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101. Considerations for chlorine dioxide treatment of drinking water.
Hoehn, Robert C.; Rosenblatt, Aaron A.; Gates, Donald J. (Virginia
Polytechnic Inst. State Univ., Blacksburg, VA 24061, USA). Proc. -
Water Qual. Technol. Conf., Volume Date 1996 63/B-74/B (English)
1997 American Water Works Association. CODEN: PWQCD2. ISSN:
0164-0755. DOCUMENT TYPE: Journal; General Review CA Section:
61 (Water)
A review with 24 refs. Used for drinking water treatment in the United
States for more than 50 yr, principally to control off-tastes, odors and
color, chlorine dioxide is of increasing importance as an alternative to
chlorine for disinfection of public water supplies. A no. of factors have
contributed to the current surge in interest in the use of chlorine dioxide
for drinking water treatment:. Chlorine dioxide does not produce the
problematic disinfection byproducts assocd. with chlorination. Chlorine
dioxide has proven effective against chlorine-resistant pathogens (e.g.,
giardia; cryptosporidium). Useful techniques for measuring chlorine
dioxide and related oxychlorine have been established. Efficient,
reliable chlorine dioxide generators are now com. available. Effective
strategies for minimizing chlorine dioxide byproducts have been
developed. In view of these advances, great benefit with few attendant
difficulties can be achieved through appropriate application of chlorine
dioxide, so long as chlorine-dioxide treatment goals are clearly
identified and certain practical guidelines are followed.
102. Carbon monoxide emissions from oxygen delignification and chlorine
dioxide bleaching of wood pulp.
Someshwar, A. V.; Dillard, D. S.; Jain, A. K.; Caron, A. L. (NCASI,
Gainesville, FL 32614, USA). Pulping Conf., Volume 2, 1029-1034.
TAPPI Press: Atlanta, Ga. (English) 1997. CODEN: 66GYAG.
DOCUMENT TYPE: Conference CA Section: 59 (Air Pollution and
Industrial Hygiene) Section cross-reference(s): 43
CO is a byproduct of bleaching pulp with ClO2 and delignification with
O2. Preliminary results from an ongoing NCASI study to examine CO
emissions from ClO2 bleaching and O2 delignification are presented.
Continuous emission monitoring systems (CEM) measured CO
emissions from vents on 4 O2 delignification systems and 6 bleach
plants in the northwestern USA. Recent CO emission data generated
by mills conducting tests in the southeastern USA on 4 O2
delignification systems and 10 bleach plants using ClO2 were also
obtained and analyzed. CEM data showed long-term av. CO
emissions were 0.05-0.4 lb/ODTBS for the 4 O2 reactors, and 0.5-1.2
lb/ODTBS for the 6 bleach plants. Including the short-term stack test
data for the southeastern O2 reactors, CO emissions appeared to
increase with total O2 charge on the brown pulp, although not all data
conformed to such a relationship. For bleaching with ClO2, CO
emissions also seemed to depend primarily on percent ClO2 applied to
the pulp, although there is significant scatter in the data.
103. Soda-AQ pulping and elemental chlorine free (ECF) bleaching of
softwood to achieve minimum impact mill.
Parthasarathy, V. R. (Technical Group Leader (Pulp/Utilities),
Willamette Industries (Kingsport Mill), Kingsport, TN 37660, USA).
Minimum Effluent Mills Symp., 127-140. TAPPI Press: Atlanta, Ga.
(English) 1996. CODEN: 66FRAO. DOCUMENT TYPE: Conference
CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood Products)
Prehydrolysis for removal of transition meals, alk. pulping, oxygen
delignification, hydrogen peroxide-reinforced two-stage oxygen
delignification, gaseous chlorine dioxide delignification, and alk. extn.
were discussed for soda-anthraquinone pulping of softwood were
discussed.
104. Gas recovery system.
Heredia, Leon M.; Battisti, Diane L.; Plocic, Michael F. (Johnson +
Johnson, USA). Eur. Pat. Appl. EP 847764 A2 17 Jun 1998, 77 pp.
DESIGNATED STATES: R: AT, BE, CH, DE, DK, ES, FR, GB, GR, IT,
LI, LU, NL, SE, MC, PT, IE, SI, LT, LV, FI, RO. (English). (European
Patent Organization). CODEN: EPXXDW. CLASS: ICM:
A61L002-20. ICS: A61L002-24. APPLICATION: EP 97-310027 11
Dec 1997. PRIORITY: US 96-764794 12 Dec 1996. DOCUMENT
TYPE: Patent CA Section: 10 (Microbial, Algal, and Fungal
Biochemistry) Section cross-reference(s): 48, 59
App. and methods are presented for generating, administering, extg.
and recovering sterilant gas for sterilizing and/or decontaminating
enclosed spaces such as, e.g., interior spaces of microbial isolators,
and also to components assocd. with such app. and methods.
Specifically contemplated herein is an arrangement for extg. gas, such
as decontaminant gas, that includes a selectively removable
arrangement for holding a predetd. quantity of a medium for interacting
with gas, such as decontaminant gas, and promoting the recovery
therefrom of at least one predetd. ingredient. Such arrangements may
conceivably be used in contexts other than contexts of app. and
methods for generating, administering, extg. and recovering sterilant
gas for sterilizing and/or decontaminating enclosed spaces.
105. Optical measurement system for sterilizing gas.
Heredia, Leon M.; Battisti, Diane L.; Vuono, Michael J. (Johnson +
Johnson, USA). Eur. Pat. Appl. EP 847759 A2 17 Jun 1998, 77 pp.
DESIGNATED STATES: R: AT, BE, CH, DE, DK, ES, FR, GB, GR, IT,
LI, LU, NL, SE, MC, PT, IE, SI, LT, LV, FI, RO. (English). (European
Patent Organization). CODEN: EPXXDW. CLASS: ICM:
A61L002-20. ICS: A61L002-24. APPLICATION: EP 97-309989 11
Dec 1997. PRIORITY: US 96-764793 12 Dec 1996. DOCUMENT
TYPE: Patent CA Section: 9 (Biochemical Methods)
App. and methods for generating, administering, extg. and recovering
sterilant gas for sterilizing and/or decontaminating enclosed spaces
such as, for example, interior spaces of microbial isolators, and also to
components assocd. with such app. and methods are disclosed.
Specifically contemplated herein, inter alia, is an arrangement for detg.
the concn. of a given component of fluid or gas, including an
arrangement, responsive to an arrangement for sensing the intensity of
radiation emitted by an emitter, for providing a correcting feedback to
the emitter. This detg. arrangement may conceivably be utilized in
contexts other than contexts of app. and methods for generating,
administering, extg. and recovering sterilant gas for sterilizing and/or
decontaminating enclosed spaces.
106. Apparatus and method for oxidization treatment.
Ookura, Hiroyuki; Masuda, Shigeki (Ookura, Hiroyuki; Masuda,
Shigeki, Japan). Jpn. Kokai Tokkyo Koho JP 10165488 A2 23 Jun
1998 Heisei, 5 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS:
ICM: A61L002-20. ICS: A61K007-06; A61L009-04. APPLICATION:
JP 96-358376 9 Dec 1996. DOCUMENT TYPE: Patent CA Section:
63 (Pharmaceuticals) Section cross-reference(s): 17, 62
A method for oxidization treatment for sterilization and deodorization
uses an app. contg. chlorine dioxide-, hydrogen peroxide- or
chlorine-contg. silica gel that generate gasses having oxidn. capability.
The app. also can be used in hair treatment. Diagrammatic views of
the app. are presented.
107. SO2, OClO, BrO, and other minor trace gases from the global ozone
monitoring experiment (GOME).
Eisinger, Michael; Burrows, John P.; Richter, Andreas;
Ladstatter-Weissenmayer, Annette (Alfred Wegener Institute for Polar
and Marine Research, Potsdam D-14473, Germany). Eur. Space
Agency, [Spec. Publ.] ESA SP, ESA SP-414(Vol. 2, Space at the
Service of Our Environment), 675-680 (English) 1997 ESA
Publications Division. CODEN: ESPUD4. ISSN: 0379-6566.
DOCUMENT TYPE: Journal CA Section: 59 (Air Pollution and Industrial
Hygiene) Section cross-reference(s): 53, 79
The Global Ozone Monitoring Expt. (GOME) on board ESA's 2nd
European Remote Sensing Satellite (ERS-2) measures earth radiance
and solar irradiance spectra between 240 and 790 nm. Inversion of
these measurements enables a variety of atm. trace gases having
banded absorptions in this wavelength range to be retrieved. The
"strong" absorber ozone is GOME's primary target species. However,
the amts. of a no. of important atm. trace gases which have relatively
weak atm. absorptions compared to ozone can also be retrieved. This
study focuses on the detection of "weak" absorbers by means of the
Differential Optical Absorption Spectroscopy (DOAS) method. GOME
measurements of SO2 are reported for the Dec. 1996 eruption of the
Nyamuragira volcano, Zaire. Furthermore, first results from an
investigation of OClO and BrO column measurements obtained from
the GOME data are presented for the Antarctic ozone holes of 1995
and 1996. Similarly, the status of the investigations is reported for the
retrieval of HCHO, NO3, and ClO.
108. Kit and method for preparing aqueous chlorine dioxide solution.
Ogawa, Katsutoshi; Oyama, Shoko (Chisso Corp., Japan). Jpn. Kokai
Tokkyo Koho JP 10182105 A2 7 Jul 1998 Heisei, 5 pp. (Japanese).
(Japan). CODEN: JKXXAF. CLASS: ICM: C01B011-02. ICS:
B01F003-08; B65D081-32; C02F001-50; C02F001-76.
APPLICATION: JP 96-354317 19 Dec 1996. DOCUMENT TYPE:
Patent CA Section: 49 (Industrial Inorganic Chemicals)
The kit consist of 3 containers each filled with aq. chlorite soln., aq.
hypochlorite soln., and aq. acid soln. sep. Aq. ClO2 soln. is prepd. by
mixing the 3 solns. in water. Aq. solns. ideal for disinfection are
obtained.
109. Use of chlorine dioxide as a disinfectant for water treatment.
Korzhenyak, I. G.; Romashin, O. P.; Mirkis, V. I.
(Mosvodokanalniiproekt, Russia). Vodosnabzh. Sanit. Tekh., (10),
10-12 (Russian) 1997 Stroiizdat. CODEN: VSTEAO. ISSN:
0321-4044. DOCUMENT TYPE: Journal CA Section: 61 (Water)
The advantages of using ClO2 for water disinfection are discussed.
Water disinfection with ClO2 nearly completely removed the smell of
manure from the water.
110. The effect of chloride on the HClO2-HOCl2 reaction in a 4.5 mol/L
sulfuric acid solution.
Yin, G.; Ni, Y. (Dr. Jack McKenzie Limerick Pulp and Paper Research
and Education Centre, University of New Brunswick, Fredericton, NB
E3B 6C2, Can.). Can. J. Chem. Eng., 76(2), 248-252 (English) 1998
Canadian Society for Chemical Engineering. CODEN: CJCEA7.
ISSN: 0008-4034. DOCUMENT TYPE: Journal CA Section: 49
(Industrial Inorganic Chemicals) Section cross-reference(s): 43, 67
The chlorous acid reaction with hypochlorous acid (chlorine) may be
responsible for the chlorine dioxide formation in a methanol based
chlorine dioxide generation process. In this paper, the reaction
between chlorous acid and hypochlorous acid in a 4.5 mol/L sulfuric
acid soln. was studied. It was found that chlorine dioxide is generated
only if chloride is present. The underlying mechanism assocd. with the
effect of chloride on the reaction was discussed.
111. Structure, vibrational spectra and energetics of OBrO+.
Francisco, Joseph S. (Department of Chemistry and Department of
Earth and Atmospheric Sciences, Purdue University, West Lafayette,
IN 47907-1393, USA). Chem. Phys. Lett., 288(2,3,4), 307-310
(English) 1998 Elsevier Science B.V. CODEN: CHPLBC. ISSN:
0009-2614. DOCUMENT TYPE: Journal CA Section: 73 (Optical,
Electron, and Mass Spectroscopy and Other Related Properties)
Structural, energetic and vibrational frequency data for OBrO+ are
calcd. at the MP2, MP4 and CCSD(T) levels of theory. The adiabatic
ionization potential for OBrO is 234.3 * 3 kcal mol-1, and is calibrated
using the adiabatic ionization potential for OClO. From the calibration,
the probable uncertainty in the adiabatic potential for OBrO is estd.
112. Bleaching of cellulosic pulp with ozone and peracids.
Fuhrmann, Agneta (Oy Keskuslaboratorio - Centrallaboratorium AB;
Fuhrmann, Agneta, Finland). PCT Int. Appl. WO 9823811 A1 4 Jun
1998, 40 pp. DESIGNATED STATES: W: AL, AM, AT, AU, AZ, BA,
BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GE,
GH, HU, ID, IL, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU,
LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG,
SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZW, AM, AZ, BY,
KG, KZ, MD, RU, TJ, TM; RW: AT, BE, BF, BJ, CF, CG, CH, CI, CM,
DE, DK, ES, FI, FR, GA, GB, GR, IE, IT, LU, MC, ML, MR, NE, NL, PT,
SE, SN, TD, TG. (English). (World Intellectual Property Organization).
CODEN: PIXXD2. CLASS: ICM: D21C009-153. ICS: D21C009-16.
APPLICATION: WO 97-FI730 26 Nov 1997. PRIORITY: FI 96-4715 26
Nov 1996. DOCUMENT TYPE: Patent CA Section: 43 (Cellulose,
Lignin, Paper, and Other Wood Products)
Pulp is treated with ozone in *1 bleaching stage. Ozone-treated pulp is
brought into contact with a peroxy alkanoic acid under acid conditions
in order to reduce the pulp's alkali lability, and the resulting pulp is
subjected to an alk. extn. stage or peroxide bleaching stage. The
bleaching sequences are thus of type Z/Paa/E or Z/Paa/P, for example,
where Z, Paa, and P indicate an ozone, peroxy acid, and peroxide
state, resp. The pulp has a kappa no. of <2, a viscosity of >600 mL/g,
a tear index (T70) of >13 mN譵2/g and a zero-span tensile index (T70)
as measured from a wet sheet of >100 N譵/g.
113. Interaction of hydrogen peroxide and chlorine dioxide stages in ECF
bleaching.
Senior, David J.; Hamilton, Janice; Ragauskas, Arthur J.; Sealey,
James; Froass, Peter (Pioneer Technol. Cent., Missisauga, ON L5K
2L3, Can.). Tappi J., 81(6), 170-178 (English) 1998 TAPPI. CODEN:
TAJODT. ISSN: 0734-1415. DOCUMENT TYPE: Journal CA Section:
43 (Cellulose, Lignin, Paper, and Other Wood Products)
Changing the order of the hydrogen peroxide (P) and chlorine dioxide
(D) stages in an ECF (elemental chlorine free) bleach sequence was
shown to affect the final brightness of kraft pulps. Application of a
D(EOP)DPP bleach sequence to a southern soft-wood pulp produced
consistently higher interstage and final brightnesses than a
D(EOP)PDP sequence. These results were confirmed by bleaching a
northern softwood and a eucalypt pulp using DEDP and DEPD
sequences. In all cases, higher brightnesses were achieved when the
second D stage (D2) preceded the P stage. The effect was esp.
evident with the hardwood pulp, where brightness of the DEDP pulp
was three points higher than the DEPD pulp. NMR anal. of extd. lignin
showed that the D2 stage reduced the phenolic lignin content of
softwood pulp by 60%, while the P stage had no effect. For the
hardwood pulp, the D2 stage reduced the phenolic lignin content by
90-95%. The greater bleaching efficiency of a DEDP sequence
(compared with DEPD) is consistent with known reactivities of
hydrogen peroxide and chlorine dioxide toward specific lignin
structures. The D2 stage lowers the phenolic lignin content of pulp while
generating hydrogen peroxide-sensitive, nonphenolic lignin species. A
followup P stage reacts effectively with this lignin.
114. Shive and knot elimination with TCF and ECF bleaching sequences.
Strom, Maria; Bergnor-Gidnert, Elisabeth; Mellander, Pia (Dep. Pulp
and Paper Chem. Technol., R. Inst. Technol., Stockholm S-100 44,
Swed.). Tappi J., 81(6), 163-169 (English) 1998 TAPPI. CODEN:
TAJODT. ISSN: 0734-1415. DOCUMENT TYPE: Journal CA Section:
43 (Cellulose, Lignin, Paper, and Other Wood Products)
Comparisons were made between bleaching stages that include
hydrogen peroxide (P), peracetic acid (T), ozone (Z), and chlorine
dioxide (D). Shives or knots were added to particle free pulp before
bleaching. The efficiencies of particle removal in totally chlorine free
(TCF) and elemental chlorine free (ECF) sequences were compared.
Using a QPQ(PO)* sequence, it is possible to obtain the same degree
of shive elimination as with ECF bleaching. Other TCF sequences do
not show the same capacity for reducing particles. If an ozone or
peracetic acid state precedes a final hydrogen peroxide stage,
problems with cleanliness may occur in the final pulp. However, mech.
treatment after final bleaching improves shive elimination in all TCF
sequences.
115. Studies of chlorine dioxide delignification: vapor phase bleaching of
hardwood and softwood kraft pulps.
Mcdonough, Thomas J.; Ragauskas, Arthur J.; Shaket, Alexander;
Sezgi, Umit S. (Institute of Paper Science and Technology, Atlanta, GA
30318, USA). Int. Environ. Conf. Exhib., Volume Bk. 3, 1121-1129.
TAPPI Press: Atlanta, Ga. (English) 1998. CODEN: 66BYAP.
DOCUMENT TYPE: Conference CA Section: 43 (Cellulose, Lignin,
Paper, and Other Wood Products)
Lab. vapor phase ClO2 delignification expts. were performed on
hardwood pulps made from sweet gum by lab. simulations of both
conventional and RDH kraft pulping. A smaller no. of expts. were
conducted on pulps made from southern pine by lab. simulations of
conventional kraft pulping. All expts. consisted of D0(EO) bleaching
followed by detn. of kappa no. and anal. of the individual stage filtrates
for AOX, as well as chloride, chlorate, and chlorite ions. For
comparison, control expts. were done in which the ClO2 was applied at
low consistency, in the conventional manner. In bleaching the
hardwood pulps, vapor phase delignification was remarkably more
efficient, but generated markedly larger quantities of AOX than the
conventional process, which itself generated much more AOX than
expected on the basis of earlier softwood pulp bleaching data. These
observations, together with analyses of the bleaching filtrates, are
consistent wit the hypothesis that ClO2 partially decomps. to Cl in the
vapor phase before reacting with the pulp. In the case of southern pine
kraft pulps, there was a much smaller improvement in delignification
efficiency in going from low consistency to vapor phase bleaching.
Qual. similar observations were made with regard to the softwood
pulps, but the trends were generally less pronounced than in the case of
the hardwood pulps. Differences in the structure of hardwood pulp
residual lignin after conventional and vapor phase bleaching were
slight. This may indicate that the superior bleaching efficiency of the
vapor phase process is caused by diminished importance of reactions
that occur between active Cl compds. and dissolved org. byproducts.
116. Complex use of hydrogen peroxide during bleaching of sulfate pulp.
Fedorova, E. I.; Nikulina, L. A.; Merkulova, T. A.; Terzi, A. I.; Kalinin, N.
N. (Syktyvkar. Fil., St. Peterburg. Lesotekh. Akad., Russia). Izv. Vyssh.
Uchebn. Zaved., Lesn. Zh., (6), 59-63 (Russian) 1997 Arkhangel'skii
Gosudarstvennyi Tekhnicheskii Universitet. CODEN: IVZLAL. ISSN:
0536-1036. DOCUMENT TYPE: Journal CA Section: 43 (Cellulose,
Lignin, Paper, and Other Wood Products)
The use of hydrogen peroxide in pulp bleaching has been detd. to be
the most efficient in the combination with other bleaching reagents,
such as ClO2 and oxygen. In this case, hydrogen peroxide, depending
on pH medium, can display both nucleophilic and electrophilic
properties. The effect of bleaching conditions in multistage sulfate pulp
bleaching was detd.
117. Vibrational relaxation of ClO2 in water.
Poulsen, J. Aa.; Thomsen, C. L.; Keiding, S. R.; Tho/gersen, J.
(Department of Chemistry, University of Aarhus, Langelandsgade 140,
Aarhus DK-8000, Den.). J. Chem. Phys., 108(20), 8461-8471
(English) 1998 American Institute of Physics. CODEN: JCPSA6.
ISSN: 0021-9606. DOCUMENT TYPE: Journal CA Section: 74
(Radiation Chemistry, Photochemistry, and Photographic and Other
Reprographic Processes) Section cross-reference(s): 73
Photodissocn. of ClO2 in aq. soln. at 400 nm results in the formation of
ClO + O and Cl + O2. ClO and O geminately recombine to ClO2 in the
electronic ground state (2B1), formed with an initial vibrational energy of
u2.5 eV. In this paper the vibrational relaxation of ClO2(2B1) in aq. soln.
is studied by femtosecond transient absorption spectroscopy in the
spectral range 234 to 1024 nm. The measured transient absorption of
the vibrationally relaxing ClO2 mols. is compared with the transient
absorption calcd. for relaxation in the asym. stretch as well as the sym.
stretch and bending modes. The calcns. of the absorption spectra
pertaining to the asym. stretch are based on a harmonic potential
derived from the exptl. detd. fundamental vibrational energy, whereas
that of the sym. vibrations are based on ab initio potentials. An
excellent agreement is obtained by assuming that the vibrational
relaxation predominantly occurs in the asym. stretch with a 9.5 ps
relaxation time. A weak spectral feature in the UV part of the spectrum
is assigned to vibrational relaxation in the sym. stretch and bending
modes, indicating a coupling between the asym. and sym. modes.
118. Paper mill freshwater treatment: life after chlorine.
Mouche, Richard J.; Kelly, Robert F. (Nalco Chem. Co., Naperville, IL,
USA). Tappi J., 81(6), 71-75 (English) 1998 TAPPI. CODEN:
TAJODT. ISSN: 0734-1415. DOCUMENT TYPE: Journal CA Section:
61 (Water) Section cross-reference(s): 43
System inoculation is a primary factory affecting performance of a
microbiol. deposit control program. Despite current trends toward
increased closure of mill water loops, freshwater remains the largest
raw material used in the papermaking process. As such, this water
supply represents a significant source of microbial inoculation into a
paper mill. Many pulp and paper mills are reconsidering the use of Cl
gas for freshwater treatment due to safety and environmental concerns.
Development of alternative chemistries may preclude Cl gas as the
best choice for paper mill freshwater treatment. Cl gas as a freshwater
biocide was studied to evaluate the performance of alternative
oxidizing biocides. The following topics are discussed: best practices
approach; assessing freshwater treatment role (biocidal efficacy, color
removal, sol. Fe and Mn oxidn., raw water clarification); what are the
alternatives; effects of alternative programs (paper machine operation,
machine clothing and system corrosion, demineralizer performance,
compatibility with other process additives); and detg. Cl replacement
cost.
119. Experience at 100% substitution bleaching and the cluster rule.
Hinck, Matthew L.; Stuart, Ronald (Simpson Tacoma Kraft Company,
Tacoma, WA 98401, USA). Int. Environ. Conf. Exhib., Volume Bk. 1,
73-83. TAPPI Press: Atlanta, Ga. (English) 1998. CODEN: 66BYAP.
DOCUMENT TYPE: Conference CA Section: 43 (Cellulose, Lignin,
Paper, and Other Wood Products)
A Washington state kraft pulp mill operates a 3-stage bleaching
process that has operated at 85% ClO2 substitution since 1991. The
historical AOX discharge for the mill is 0.95 kg/admt, which is higher
than the requirements outlined in EPA's new cluster rule. The mill
conducted a 7-mo trial, by operating the bleach plant at 100%
substitution to det. environmental performance for AOX, 2,3,7,8-TCDD,
CHCl3, and the 12 chlorinated phenolics. The trial results showed that,
at a pre-bleach kappa no. of *26, the mill should be in compliance with
the new EPA cluster rule regulations for the aforementioned compds.
Such results allow the mill to plan for the future and focus future work on
optimization and expansion.
120. Suspended bacterial biomass and activity in full-scale drinking water
distribution systems: impact of water treatment.
Prevost, Michele; Rompre, Annie; Coallier, Josee; Servais, Pierre;
Laurent, Patrick; Clement, Bernard; Lafrance, Pierre (NSERC Chair on
Drinking Water, Civil Engineering, Ecole Polytechnique de Montreal,
Montreal, PQ H7N 3A7, Can.). Water Res., 32(5), 1393-1406 (English)
1998 Elsevier Science Ltd. CODEN: WATRAG. ISSN: 0043-1354.
DOCUMENT TYPE: Journal CA Section: 61 (Water)
Bacterial regrowth in drinking water distribution systems is a source of
concern, since it could result in noncompliance with water quality
regulations and taste and odor problems and may be assocd. with an
increased risk of gastrointestinal illness. Bacterial regrowth is
dependent on several factors, including the amt. of substrate available
for growth, such as biodegradable dissolved org. carbon (BDOC),
oxidant residuals, and the presence of corrosion. To investigate the
impact of nitrient levels and oxidant residual maintenance, a full-scale
investigation of two distribution systems (DSs) was completed. This
study presents data obtained from two DSs fed by different treatment
trains: one DS has low BDOC concns. and no free oxidant residual (St.
Rose plant, Quebec, Canada), and the other has a high BDOC concn.
and moderate concns. of free oxidant residual (Pont Viau plant,
Quebec, Canada). Monitoring included heterotrophic plate counts
(HPC), total direct count by epifluorescence after acridine orange
staining (AODC), direct viable counts (DVC-CTC method), and the
measurement of bacterial prodn. by 3H-thymidine incorporation. The
results show that bacterial biomass (AODC and DVC) and bacterial
prodn. are lower in the DS fed by the treatment plant with a low BDOC
concn. in the plant effluent. This difference is obsd. in warm water but
not in cold water. The results suggest that HPCs are not a good
indicator of bacterial regrowth in DSs. Finally, statistical anal.
demonstrated that the treatment type and cumulative surface-to-vol.
ratio are the significant factors affecting regrowth in the distribution
systems studied in warm waters.
121. Comparison of the ACVK and LGB methods for measuring chlorine
dioxide in drinking water.
Hofmann, Ron; Ye, Quanfang; Andrews, Robert C. (Department of Civil
Engineering, University of Toronto, Toronto, ON M5S 1A4, Can.). Proc.
- Water Qual. Technol. Conf., P12F/1-P12F/15 (English) 1997
American Water Works Association. CODEN: PWQCD2. ISSN:
0164-0755. DOCUMENT TYPE: Journal CA Section: 61 (Water)
Section cross-reference(s): 79
Two spectrophotometric methods for measuring residual ClO2 in
drinking water, one using acid chrome violet K (ACVK) reagent and the
other using lissamine green B (LGB), were evaluated and compared.
The linear range (without diln., at 20*) of the LGB method was 0.02-2
mg/L, while that using ACVK was 0.08-2.5 mg/L. Both methods were
free of interferences from Cl, chloramines, chlorite, and chlorate, at
concns. >5 mg/L. The LGB method was also unaffected by
permanganate at concns. as high as 6 mg/L, however, permanganate
did cause a significant neg. error in ClO2 measurements when using
ACVK.
122. Prebleaching of paper pulp before peroxide bleaching stage.
Germgard, Ulf (Sunds Defibrator Industries AB; Germgard, Ulf, Swed.).
PCT Int. Appl. WO 9821400 A1 22 May 1998, 11 pp. DESIGNATED
STATES: W: AU, BR, CA, CN, JP, NO, NZ, US; RW: AT, BE, CH, DE,
DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE. (English). (World
Intellectual Property Organization). CODEN: PIXXD2. CLASS: ICM:
D21C009-10. ICS: D21C009-14; D21C009-16. APPLICATION: WO
97-SE1810 29 Oct 1997. PRIORITY: SE 96-4094 8 Nov 1996.
DOCUMENT TYPE: Patent CA Section: 43 (Cellulose, Lignin, Paper,
and Other Wood Products)
A method for bleaching papermaking pulp with peroxide with enhanced
efficiency for a chelating stage wherein the pulp after digestion, and
possibly oxygen bleaching, is subjected to a mild chlorine dioxide
treatment at acidic pH, an alkalization and a treatment with chelating
agent at a high pH before a peroxide stage.
123. Hair treatment system and kit for invigorating hair growth.
Edwards, William Thomas (Regenix Marketing Systems, Inc., USA).
U.S. US 5750108 A 12 May 1998, 5 pp. Cont. of U.S. Ser. No.
529,791, abandoned. (English). (United States of America). CODEN:
USXXAM. CLASS: ICM: A61K033-20. ICS: A61K035-78;
A61K031-34. NCL: 424195100. APPLICATION: US 97-829623 31
Mar 1997. PRIORITY: US 95-529791 18 Sep 1995. DOCUMENT
TYPE: Patent CA Section: 62 (Essential Oils and Cosmetics)
A method for hair treatment is disclosed wherein a first treatment soln.
comprising tea tree oil is periodically applied to the scalp for at least 10
days. Then, a second treatment soln. comprising chlorine dioxide is
periodically applied to the scalp, immediately followed by application of
an acidic soln. having an acidity effective to release the oxygen in the
chlorine dioxide soln., for at least 1 mo. Finally, a third treatment soln.
comprising saw palmetto berry ext. is periodically applied to the scalp
for at least 1 mo. Also disclosed is a hair treatment kit. For example,
the dil. tea tree oil soln. is massaged into the scalp where it is left for 8
h and this treatment is continued for 3 times per wk over a period of 21
days to emulsify waxy sebum from the follicle entrance and to normalize
topical scalp problems such as itching, dandruff, excessive oiliness and
dryness, and to increase blood circulation to the scalp. Then, an aq.
soln. contg. 500 ppm chlorine dioxide is massaged into the scalp,
immediately followed by an aq. soln. contg. enough citric acid to adjust
the pH to about 4.0. and the hair is washed after 8 h; this treatment is
continued for 3 times per wk for 1 mo to oxidize 5a-reductase and
make it inactive, and to continue to eliminate follicle debris. Finally,
100 % saw palmetto berry ext. is massaged into the scalp, followed by
10 min under a heat cap; subsequently, a soln. contg. deionized water,
alc. SDA-40, biotin, folic acid, Zn picolinate, niacin, and hydrolyzed
keratins and a nicotinate soln. contg. water, alc. SDA-40, menthol,
panthenol, salicylic acid, menthol nicotinate, niacin, biotin, herbal exts.,
and fragrance, is massaged into the scalp, followed by an addnl. 10
min under a heat cap. The above solns. are washed from the hair after
8 h; this treatment is designed to utilize the 5a-reductase inhibiting
properties along with the dihydrotestosterone receptor site binding
characteristics of saw palmetto, and it is continued for 3 times per wk
for 6 mo.
124. Spectrophotometric determination of chlorine dioxide in water with the
decolorization of Neutral Red.
Kang, Xuejun; Fan, Xingrong; Zhang, Disheng; Wang, Yu (Jiangsu
Provincial Inst. Medical Industry, Nanjing 210042, Peop. Rep. China).
Fenxi Huaxue, 26(5), 619 (Chinese) 1998 Zhongguo Huaxuehui "Fenxi
Huaxue" Bianji Weiyuanhui. CODEN: FHHHDT. ISSN: 0253-3820.
DOCUMENT TYPE: Journal CA Section: 61 (Water) Section
cross-reference(s): 79
A spectrophotometric method for the detn. of chlorine dioxide in water
with the decolorization of Neutral Red as indicator has a detection limit
0.01 mg/L and linearity range in 0-30 mg/L.
125. Determination of inorganic chlorine species in kraft mill bleach effluents
by ion chromatography.
Sullivan, Joseph; Douek, Maurice (Pulp and Paper Res. Inst. Canada,
Pointe Claire, PQ H9R 3J9, Can.). J. Chromatogr., A, 804(1 + 2),
113-121 (English) 1998 Elsevier Science B.V. CODEN: JCRAEY.
ISSN: 0021-9673. DOCUMENT TYPE: Journal CA Section: 61
(Water) Section cross-reference(s): 60, 79
A sensitive ion chromatog. method has been developed for the detn. of
chlorine dioxide, chloride, chlorite, chlorate and several other anions in
kraft mill bleach effluents. The new method overcomes problems found
in existing methods, such as low recovery of chlorine dioxide and poor
resoln. of chlorite from org. anions. The effects of storage time and
temp. on the stability of inorg. chlorine species and other ions, in first
bleaching, first extn., final bleaching and combined mill effluent samples
were also studied. In addn., the efficacy of ethylenediamine as a
preservative for chlorite and its impact on chlorine dioxide in stored
samples of final bleaching stage effluent were assessed.
126. In situ remediation of petroleum compounds in groundwater aquifer with
chlorine dioxide.
Kun, Zhu; Hui, Chen; Guanghe, Li; Zhaochang, Liu (Dep. of
Environmental Engineering, Lanzhou Railway Institute, Gansu 730070,
Peop. Rep. China). Water Res., 32(5), 1471-1480 (English) 1998
Elsevier Science Ltd. CODEN: WATRAG. ISSN: 0043-1354.
DOCUMENT TYPE: Journal CA Section: 61 (Water)
A comparison was made of the remedial effect on org. contaminants
using ozone, chlorine dioxide, potassium permanganate and hydrogen
peroxide in lab. tests. Chlorine dioxide was chosen for use in in situ
remediation of a petroleum contaminated aquifer. The lab. expts.
indicated that oxidn. capacity of chlorine dioxide was affected by
reaction time, gas injection method, and pH of groundwater. A
pilot-scale field expt. was conducted through the oxidn. treatment
involving the injection of chlorine dioxide soln. into the aquifer where
pollutants included more than 80 org. compds. contg. 14 mutagens.
The in situ oxidn. treatment proved that most of the org. contaminants
including 5 mutagenic compds. were decompd. or removed and 19
new byproducts were found without mutagenic carcinogens. The
results shows that the unsatd. hydrocarbons were easily removed
excluding that some of satd. alkane and alkene and polycyclic arom.
hydrocarbons and heterocyclic compds. were not oxidizable. The oil
concn. in groundwater reduced by 50-60%. It was evident that
desorption of org. contaminants from aquifer media significantly
affected the groundwater quality during remediation process.
Therefore, groundwater remediation must include aquifer media
cleaning. Degrdn. of benzene, toluene, ethylbenzene, p-toluene,
o-toluene, m-toluene, and styrene are given.
127. Excited-State Reaction Dynamics of Chlorine Dioxide in Water from
Absolute Resonance Raman Intensities.
Foster, Catherine E.; Reid, Philip J. (Department of Chemistry,
University of Washington, Seattle, WA 98195, USA). J. Phys. Chem.
A, 102(20), 3514-3523 (English) 1998 American Chemical Society.
CODEN: JPCAFH. ISSN: 1089-5639. DOCUMENT TYPE: Journal
CA Section: 74 (Radiation Chemistry, Photochemistry, and
Photographic and Other Reprographic Processes) Section
cross-reference(s): 73
Resonance Raman spectra of aq. chlorine dioxide (OClO) are
measured for several excitation wavelengths spanning the photochem.
relevant 2B1-2A2 optical transition. A mode-specific description of the
optically prepd., 2A2 potential energy surface is derived by
simultaneous anal. of the abs. resonance Raman and absorption cross
sections. The resonance Raman spectra are dominated by transitions
involving the sym. stretch and bend coordinates demonstrating that
excited-state structural evolution occurs predominately along these
degrees of freedom. Scattering intensity is not obsd. for transitions
involving the asym. stretch, demonstrating that excited-state structural
evolution along this coordinate is modest. The limited evolution along
the asym. stretch coordinate results in the preservation of C2v symmetry
on the 2A2 surface. It is proposed that this preservation of symmetry is
responsible for the increase in Cl photoproduct quantum yield in soln.
relative to the gas phase. Anal. of the abs. scattering cross sections
also demonstrates that the homogeneous line width for the 2B1-2A2
optical transition in water is essentially identical to that in cyclohexane;
however, the extent of inhomogeneous broadening increases
dramatically in aq. soln. Comparison of the spectroscopic properties
of OClO to the properties of isoelectronic O3- is made to elucidate the
origin of the solvent response to OClO photoexcitation. It is suggested
that solvent-solute dipole-dipole coupling and intermol. hydrogen
bonding represent the largest components of the solvent coordinate.
128. Removal of chlorite ion using sulfite ion in natural waters.
Gregory, Dean; Carlson, Kenneth; Gordon, Gilbert; Bubnis, Bernard
(Fort Collins Water Utility, Fort Collins, CO, USA). Proc. - Water Qual.
Technol. Conf., 3E6/1-3E6/12 (English) 1997 American Water Works
Association. CODEN: PWQCD2. ISSN: 0164-0755. DOCUMENT
TYPE: Journal CA Section: 61 (Water)
The use of chlorine dioxide as an alternative disinfectant and for other
purposes such as manganese oxidn. may be impacted by the
impending MCL of 1.0 mg/L proposed for chlorite ion under Stage I of
the D/DBP Rule, which is to take effect in Nov., 1998. Treatment
facilities which routinely apply chlorine dioxide doses in the range of
1.3-1.5 mg/L or higher may be forced to implement chlorite removal
methods to be in compliance with the MCL. This study evaluated the
use of sulfite ion for chlorite ion removal in chlorine dioxide-treated
waters. The effects of pH, sulfite dose, and initial chlorite ion concn.
were investigated. The effect of sulfite ion on newly-formed
manganese oxides was also examd. For initial chlorite ion concns. of
1.0 mg/L, sulfite ion doses of 15-20 mg/L effectively removed chlorite
ion when the pH was below approx. 6.5, without significant chlorate ion
formation. When the pH was raised to 7.0, sulfite ion doses greater
than 30 mg/L were required. The application of sulfite ion to water
contg. manganese dioxide (formed by the ClO2/Mn2+ reaction) was
shown to cause significant resolubilization of manganese solids unless
adequate flocculation time was provided following alum addn.
129. Pilot-study report, mixed oxidant disinfection system at Greenfield,
Iowa.
Herrington, Rodney E.; Bradford, Wesley L. (MIOX Corporation,
Albuquerque, NM, USA). Proc. - Water Qual. Technol. Conf.,
P6J/1-P6J/17 (English) 1997 American Water Works Association.
CODEN: PWQCD2. ISSN: 0164-0755. DOCUMENT TYPE: Journal
CA Section: 61 (Water) Section cross-reference(s): 48, 72
Greenfield, Iowa, pilot-tested the MIOX Trigen mixed oxidant
disinfection system to verify: consistent mixed oxidant feed dose;
provision of more stable Cl residuals; persistent residual at distribution
system limits; ultimate trihalomethane disinfection byproduct redn.;
improved water clarity, i.e., reduced turbidity; taste and odor redn.; and
elimination of potassium permanganate and redn. of coagulant
demand during colder operational months in the pretreatment portion of
the plant. These verification issues were important considerations in
the decision to continue mixed oxidant disinfection and equipment
purchase for permanent installation. This mixed oxidant system
provided improvements in all conditions vs. gas chlorination.
130. Treatment of chlorine dioxide generator effluent and feed streams with
fixed-resin bed.
Paleologou, Michael; Thompson, Rokhsareh; Brown, Craig J.; Sheedy,
Michael (Pulp and Paper Research Institute of Canada; Eco-Tec
Limited; Paleologou, Michael; Thompson, Rokhsareh; Brown, Craig
J.; Sheedy, Michael, Can.). PCT Int. Appl. WO 9816462 A1 23 Apr
1998, 86 pp. DESIGNATED STATES: W: AL, AM, AT, AU, AZ, BA,
BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GE,
GH, HU, ID, IL, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU,
LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG,
SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZW, AM, AZ, BY,
KG, KZ, MD, RU, TJ, TM; RW: AT, BE, BF, BJ, CF, CG, CH, CI, CM,
DE, DK, ES, FI, FR, GA, GB, GR, IE, IT, LU, MC, ML, MR, NE, NL, PT,
SE, SN, TD, TG. (English). (World Intellectual Property Organization).
CODEN: PIXXD2. CLASS: ICM: C01B011-02. ICS: C01D005-16;
C01B017-90. APPLICATION: WO 97-CA750 9 Oct 1997. PRIORITY:
US 96-729148 11 Oct 1996. DOCUMENT TYPE: Patent CA Section:
43 (Cellulose, Lignin, Paper, and Other Wood Products) Section
cross-reference(s): 61
A process is disclosed employing a fixed-resin bed Acid Retardation
Unit (ARU) to sep. spent acid from ClO2 generators into a de-acidified
sodium sulfate component and a purified sulfuric acid component. The
de-acidified sodium sulfate produced is returned to the chem. recovery
cycle of the kraft mill in place of acidic ClO2 generator effluent thereby
avoiding the destruction of alky. in pulp mill liquors. In addn., sulfuric
acid is purified providing an opportunity for reuse in various mill
applications, and/or concd. and recycled to the generator. Alternatively,
to avoid high evapn. costs, the purified acid can be used to regenerate
a cation-exchange unit (CEU) used in the conversion of sodium
chlorate to a sodium chlorate/chloric acid mixt. which is fed to the
generator in place of sodium chlorate and sulfuric acid. Using this
approach, the sulfuric acid requirement of ClO2 generators and, in turn,
the amt. of acidic generator effluent can be reduced. The process is
applicable to both atm. and subatmospheric ClO2 generators. In the
latter case, the concn. of the purified sulfuric acid from the ARU or any
other acid sepn. system can be increased by using a portion of it to
dissolve the sodium sesquisulfate byproduct from such generators.
131. Comparison of Various Quantum Chemistry Methods for the
Computation of Equilibrium Constants.
Bohr, Frederic; Henon, Eric (Laboratoire de Chimie Physique GSMA
UPRES-A 6089, Faculte des Sciences de Reims, Reims 51687, Fr.).
J. Phys. Chem. A, 102(25), 4857-4862 (English) 1998 American
Chemical Society. CODEN: JPCAFH. ISSN: 1089-5639.
DOCUMENT TYPE: Journal CA Section: 68 (Phase Equilibriums,
Chemical Equilibriums, and Solutions)
Ab initio and d. functional computations were carried out to test their
ability to reproduce exptl. equil. consts. Gas phase equil. involving
nitrogen oxides, methanol, and chlorine oxides were considered; the
equil. of the oxides is of relevance in studies of tropospheric pollution
and stratospheric ozone layer destruction, while MeOH equil. is of
industrial interest. The basis set effect was also examd. Hybrid
HF-DFT and G2 methods seem to be the best adapted for calcn. of
equil. consts.
132. Surface water treatment plant improvements Milford Municipal Utilities.
Catlin, Chris L. (Howard R. Green Company, Des Moines, IA 50310,
USA). Proc. - Annu. Conf., Am. Water Works Assoc., (Engineering and
Operations), 387-391 (English) 1997 American Water Works
Association. CODEN: PWACDO. ISSN: 0360-814X. DOCUMENT
TYPE: Journal CA Section: 61 (Water)
In 1994, Milford, Iowa, faced compliance with the Surface Water
Treatment Rule (SWTR). The town's water treatment plant was
equipped to meet most requirements of the new rule, but it did not have
a mechanism to allow adequate contact time between disinfectant (Cl)
application and water distribution. To remedy this situation, the plant
was updated to meet the SWTR and future regulations by: converting
the existing clear-well to a Cl contact tank and adding a new serpentine
clear well for addnl. storage; installing new equipment (coagulation and
polymer chem. feed equipment, in-line power mixer, filter controls
including filter-to-waste capability, particle counters, granular activated
C filter media, low profile underdrains); and implementing multiple
barrier technol. to remove potential water pollutants. Results showed th
project successfully enables the city to meet SWTR requirements and
has positioned the water utility for compliance with the upcoming
Disinfectant/Disinfection Byproducts and Enhanced Surface Water
Treatment rules.
133. Optimizing plant performance using chlorine dioxide: a case study at
Soldier Canyon Water Treatment Plant Fort Collins, Colorado.
Ullmann, Thomas F.; Reed, Bob; Turner, John (The Engineering Co.,
Fort Collins, CO, USA). Proc. - Annu. Conf., Am. Water Works Assoc.,
(Water Quality), 593-606 (English) 1997 American Water Works
Association. CODEN: PWACDO. ISSN: 0360-814X. DOCUMENT
TYPE: Journal CA Section: 61 (Water)
Using ClO2 to control seasonal problems with dissolved Mn at the
Soldier Canyon Water Treatment Plant, Fort Collins, Colorado, is
discussed. Results showed Cl2 treatment exceeded expectations with
respect to effective Mn removal, and it improved overall treatment
efficiency and reduced trihalomethane formation. In addn., filter
operation improved, i.e., longer filter runs. The following items should
be considered when using ClO2: best Mn removal rates occurred when
minimal ClO2 residual was carried to the filters; backwash recycle
water should be monitored to det. addnl. Mn being returned to the plant;
adjust ClO2 dose required to meet addnl. demand created by Mn return
to plant influent from backwash recycle system; maintain 95+%
generator efficiency to minimize Cl residuals; frequently monitor influent
Mn concns., ClO2 residuals throughout the plant, filter effluent Mn
concns., and effluent chlorite concns.; and increase the frequency of
solids removal from recycle point to keep recycle water Mn concns.
down. In addn., consider adjusting influent pH. An alternative may be
to use polyaluminum chloride or polyaluminum chloride/alum
combination to keep from dropping influent pH; Mn removal rates
appeared to be better when influent pH was >7.5.
134. Chlorine dioxide-related byproducts when disinfecting to Giardia and
Cryptosporidium CT criteria.
Hofmann, Ron; Ye, Quanfang; Andrews, Robert C. (Civil Engineering
Department, University of Toronto, Toronto, ON M5S 1A4, Can.). Proc.
- Annu. Conf., Am. Water Works Assoc., (Water Research), 177-195
(English) 1997 American Water Works Association. CODEN:
PWACDO. ISSN: 0360-814X. DOCUMENT TYPE: Journal CA
Section: 61 (Water) Section cross-reference(s): 10
Chlorine dioxide was applied to clarified surface water samples in
bench scale, batch reactors, for a 60 min contact time. The dosages
required to achieve varying levels of Giardia and Cryptosporidium
inactivation based on CT values were examd., as well as the
subsequent byproduct concns. Typically 1.5 to 2 mg/L of applied
chlorine dioxide was capable of 3-log Giardia inactivation at 1癈 to
25癈, and at both pH 6 and 9. Chlorine dioxide dosages of up to 3
mg/L were required to achieve 0.5-log Cryptosporidium inactivation
using a simple CT model developed for this study on the basis of
published inactivation data. Greater chlorine dioxide dosages were
typically required at 1癈 compared to 25癈, and at pH 9 when
compared to pH 6, to provide the same level of microbial inactivation.
Chlorite concns. were below 1 mg/L for 0.5 to 3-log Giardia
inactivation, however this level was exceeded when greater inactivation
levels were examd. Chlorate concns. were always less than 0.5 mg/L.
When 1.5 mg/L of chlorine was added as a secondary disinfectant in a
simulated distribution system (SDS) test, chlorite concns. at pH 6 were
reduced by 0.2 to 0.4 mg/L due to oxidn. by chlorine. At pH 9 there was
no apparent effect. Application of 0.7 to 1.2 mg/L of chlorine dioxide
resulted in a 30 mg/L redn. in subsequent THM formation at pH 9 when
chlorine was applied to provide an SDS residual, however little impact
was obsd. at pH 6.
135. Assessment of the use of chlorine dioxide at the Topeka, KS water
treatment plant.
Shelton, Sharon L.; Randtke, Stephen J. (Department of Civil and
Environmental Engineering, University of Kansas, Lawrence, KS,
USA). Proc. - Annu. Conf., Am. Water Works Assoc., (Water
Research), 171-175 (English) 1997 American Water Works
Association. CODEN: PWACDO. ISSN: 0360-814X. DOCUMENT
TYPE: Journal CA Section: 61 (Water)
Batch expts. showed that by substituting ClO2 for Cl2 as a preoxidant,
the plant should be able to readily meet the proposed Stage-1 Max.
Contaminant Levels for both trihalomethanes and haloacetic acids.
136. Numerical investigation of nonequilibrium photochemical processes in
the wake of subsonic aircraft.
Lebedev, A. B.; Starik, A. M.; Titova, N. S. (Central Institute of Aviation
Motors, Moscow 111250, Russia). High Temp., 36(1), 75-89 (English)
1998 MAIK Nauka/Interperiodica Publishing. CODEN: HITEA4. ISSN:
0018-151X. DOCUMENT TYPE: Journal CA Section: 59 (Air Pollution
and Industrial Hygiene) Section cross-reference(s): 51, 53
A quasi 1-dimensional mixing model analyzed nonequil. chem.
processes occurring in the reaction plume of subsonic aircraft. It was
shown that, as a result of nonequil. processes in the plume, compds.
may form, the values of whose concn. exceed considerably (by a factor
of 102) background concns. in undisturbed atm. and concns. at the
nozzle exit section.
137. Production and application of NaClO3, NaClO2, and ClO2.
Huang, Yunxiang (Guangzhou Haotian Chemical (Group Co. Ltd.),
Canton, Peop. Rep. China). Guangzhou Huagong, 25(3), 15-20
(Chinese) 1997 Guangzhou Huagong Bianjibu. CODEN: GUHUEZ.
ISSN: 1001-9677. DOCUMENT TYPE: Journal; General Review CA
Section: 49 (Industrial Inorganic Chemicals)
A review with 23 refs. of prodn. status, prepn. methods, and
applications of NaClO3, NaClO2, and ClO2.
138. Georgia-Pacific studies relate contaminants in process streams,
effluents.
Kemeny, Thomas E.; Banerjee, Sujit (Georgia-Pacific, Atlanta, GA,
USA). Adv. Bleaching Technol., 31-35. Edited by: Patrick, Ken L.
Miller Freeman: San Francisco, Calif. (English) 1997. CODEN:
65YZAY. DOCUMENT TYPE: Conference CA Section: 43 (Cellulose,
Lignin, Paper, and Other Wood Products)
Two studies conducted by Georgia-Pacific Corp. to assess the
environmental status of its Ga. and Miss. pulping operations, which are
both ECF (100% ClO2) bleach mills, are reported. These studies
demonstrated the absence of dioxins, chlorophenols, or acrolein in
100% ClO2 bleaching. They showed the utility of developing
relationships among contaminant profiles across various locations and
analytes. These correlations can establish source-sink relationships
and provide insight into the transport of these materials through the mill.
139. Mildew preventing method of grains.
Ye, Zhongliang (Ye, Zhongliang, Peop. Rep. China). Faming Zhuanli
Shenqing Gongkai Shuomingshu CN 1138948 A 1 Jan 1997, 4 pp.
(Chinese). (People's Republic of China). CODEN: CNXXEV. CLASS:
ICM: A23B009-18. ICS: A01N059-00. APPLICATION: CN 95-108345
29 Jun 1995. DOCUMENT TYPE: Patent CA Section: 17 (Food and
Feed Chemistry)
Chlorine dioxide is used as the effective component to kill and inhibit
mold through fumigation and spraying to prevent grains from mildewing
and rotting. The said method is safe and simple.
140. Vector correlations in the photodissociation of OClO A2A2(n1, 0, 0).
Kreher, Christoph J.; Carter, Robert T.; Huber, J. Robert
(Winterthurerstrasse 190, Physikalisch-Chemisches Institut der
Universitat Zurich, CH-8057, Zurich, Switz.). Chem. Phys. Lett.,
286(5,6), 389-397 (English) 1998 Elsevier Science B.V. CODEN:
CHPLBC. ISSN: 0009-2614. DOCUMENT TYPE: Journal CA
Section: 74 (Radiation Chemistry, Photochemistry, and Photographic
and Other Reprographic Processes) Section cross-reference(s): 73
Using resonant-enhanced multiphoton ionization combined with the
time-of-flight method, the photodissocn. OClO(A2A2) * ClO(X 2P) +
O(3P) was investigated at two wavelengths which were found to give
access to excitation below (397.5 nm) and above (359.7 nm) the
predicted exit barrier on the A2A2 surface. The complete angular
correlations between the vectors m, v and J for ClO(v=0) were detd. at
both wavelengths, providing information on the direct and indirect
dissocn. pathways on the A2A2 surface of OClO.
141. Oxidation of Peroxynitrite by Inorganic Radicals: A Pulse Radiolysis
Study.
Goldstein, Sara; Saha, Abhijit; Lymar, Sergei V.; Czapski, Gidon
(Department of Physical Chemistry, Hebrew University of Jerusalem,
Jerusalem 91904, Israel). J. Am. Chem. Soc., 120(22), 5549-5554
(English) 1998 American Chemical Society. CODEN: JACSAT. ISSN:
0002-7863. DOCUMENT TYPE: Journal CA Section: 67 (Catalysis,
Reaction Kinetics, and Inorganic Reaction Mechanisms)
Reactivity of the peroxynitrite ion toward a no. of inorg. radicals was
detd. by using the pulse radiolysis technique. The rate consts. for the
oxidn. of the ONOO- ion by CO3*-, 種3, and ClO2* radicals were detd.
from their decay kinetics to be (7.7 * 1.2) * 106 (I = 0.6 M), (7.2 * 0.9) *
108, and (3.2 * 0.3) * 104 M-1 s-1, resp. For the 稯H radical, the rate
const. of (4.8 * 0.8) * 109 M-1 s-1 was obtained by using competition
kinetic anal. The oxidn. potential of the ONOO- ion was estd. as 0.8 V
from the kinetic data. Although thermodynamically favorable, oxidn. of
ONOO- by the 種O2 radical was not obsd.; an upper limit of 2.5 * 104
M-1 s-1 could be set for this reaction. Contribution from some of these
reactions to the decompn. of peroxynitrite in the presence and absence
of CO2 is discussed.
142. Gaseous, chlorine-free chlorine dioxide for drinking water.
Gordon, Gilbert; Rosenblatt, Aaron (Miami University, Oxford, OH
45056, USA). Proc. - Water Qual. Technol. Conf., Volume Date 1995,
(Pt. 1), 457-465 (English) 1996 American Water Works Association.
CODEN: PWQCD2. ISSN: 0164-0755. DOCUMENT TYPE: Journal
CA Section: 61 (Water) Section cross-reference(s): 49
The benefits of applying chlorine dioxide (ClO2) for the oxidative
treatment of drinking water are well established. Chlorine dioxide
treated finished water typically has substantially lower trihalomethane
(THM) levels because ClO2 will not form chlorinated org. species as a
byproduct of disinfection. The THMs that are formed are probably due
to chlorine from the generator or chlorine used to maintain a
post-disinfection residual. An emerging regulatory issue concerning
the formation of disinfection byproducts (DBPs) is causing the water
industry to set stds. for the generation and delivery of ClO2. The
Federal Register (11 Feb. 1994) contains language developed to limit
the prodn. of the unwanted inorg. byproducts chlorite (ClO2-), chlorate
(ClO3-), and bromate (BrO3-) ions by requiring utilities to maintain high
(95%) generation efficiencies and by limiting the amt. of excess Cl2 that
can be used during the generation process. The efficiency and excess
Cl2 regulations may be problematic for utilities that over-chlorinate to
attain chlorine dioxide high yields. Many utilities will have to decide
either to reduce the amt. of Cl2 used to react with sodium chlorite
(NaClO2), thereby increasing the ClO2- residual in finished water, or
over-chlorinate to increase yields and surpass the excess Cl2 limits. A
new ClO2 gas technol. is available that delivers essentially 100% ClO2
gas that is Cl2 free and also eliminates ClO2- and ClO3- that are often
produced in traditional generators or carried through such systems as a
result of poor generation efficiency. The technol. affords infinite
turndown capability, meaning that if a smaller or larger dose of ClO2 is
required to meet changing demand or seasonal variations, a system
recalibration is not required to maintain generator efficiency. This
eliminates a common problem assocd. with ClO2 generation when
water flow through the treatment plant changes unexpectedly and
reduces generator efficiency.
143. Bromate ion formation in water when chlorine dioxide is photolyzed in
the presence of bromide ion.
Gordon, Gilbert; Emmert, Gary L.; Bubnis, Bernard (Department of
Chemistry, Miami University, Oxford, OH 45056, USA). Proc. - Water
Qual. Technol. Conf., Volume Date 1995, (Pt. 2), 1985-1992 (English)
1996 American Water Works Association. CODEN: PWQCD2. ISSN:
0164-0755. DOCUMENT TYPE: Journal CA Section: 61 (Water)
Section cross-reference(s): 74
Concern over the health effects of bromate ion has led to increased
scrutiny of the bromate ion formation potential of ozonation. It is widely
assumed that the major contributor to bromate ion in drinking water
comes from the ozonation of bromide ion-contg. waters. Bromate ion
formation readily occurs when ozone oxidizes bromide ion, and it has
often been assumed that this is the only mechanism of bromate ion
formation in water. Recent results from our labs. clearly show that this
is simply not the case. Many researchers and anal. labs. have reported
the observance of bromate ion in ion chromatograms of chlorine
dioxide treated water that contains bromide ion. Thus, expts. were
designed to understand the origin of bromate ion in chlorine dioxide
treated waters. Chlorine dioxide treatment of a bromide ion contg.
water has been shown to result in bromate ion formation in the
presence of UV light over a wide range of pH values. This formation
occurs in high concns. and at an appreciable rate. Furthermore, results
indicate that this mechanism appears to be photochem. in nature, since
expts. carried out under identical conditions in the absence of UV light,
did not result in bromate ion formation.
144. Neuro-reproductive toxicity issues concerning chlorine dioxide and the
chlorite ion in public drinking water supplies.
Gates, D. J.; Harrington, R. M. (Rio Linda Chemical Co., Sacramento,
CA, USA). Proc. - Water Qual. Technol. Conf., Volume Date 1995, (Pt.
1), 813-830 (English) 1996 American Water Works Association.
CODEN: PWQCD2. ISSN: 0164-0755. DOCUMENT TYPE: Journal
CA Section: 61 (Water) Section cross-reference(s): 4
A comprehensive, two-generation toxicol. study has been undertaken to
help satisfy "data gaps" identified by the USEPA for the chlorite ion
(ClO2-), a disinfection byproduct of chlorine dioxide (ClO2). As part of
the negotiated rulemaking process used to develop the Disinfectants-
Disinfection Byproduct Rule (D/DBP; 59 CFR 38668), USEPA and
other members of the Negotiating Committee asked that studies
reported here be undertaken by the Chlorine Dioxide Panel of the
Chem. Manufacturer's Assocn. Because of renewed concern over
possible fetal neuro-developmental effects, the USEPA may be
considering a lower MCL for ClO2- than is currently proposed in the
D/DBP Rule. These concerns have been exaggerated by a lack of high
quality, state-of-the-art, toxicol. data useful in deriving regulatory
setpoints. The studies chosen by the USEPA to derive the current
Maximum Contaminant Level Goal (MCLG) for ClO2- included only one
or two of the 18 necessary parameters required to properly assess
developmental neurotoxicity. The exptl. protocol employed in this
comprehensive study will be presented, along with interim data
currently available. The protocol includes a battery of 28 tests that are
required to adequately assess developmental neurotoxicity. Final
results of this ongoing study may significantly impact the extra
uncertainty factors applied in establishing the current Ref. Dose (RfD),
and possibly result in recognition of a higher NOAEL for the chlorite ion
based on this rigorous two-generation neurotoxicol. study. No decision
should be made on the MCLG for ClO2- until this study is completed in
1996 and fully evaluated by the USEPA.
145. Mechanism of the methanol based ClO2 generation process.
Ni, Y.; Wang, X. (Dr. Jack McKenzie Limerick Pulp and Paper
Research and Education Centre, University of New Brunswick,
Fredericton, NB E3B 6C2, Can.). Int. Pulp Bleaching Conf., Volume 2,
453-462. TAPPI Press: Atlanta, Ga. (English) 1996. CODEN:
65XBAP. DOCUMENT TYPE: Conference CA Section: 43 (Cellulose,
Lignin, Paper, and Other Wood Products) Section cross-reference(s):
49
The development of chlorine dioxide, chlorous acid, chlorine, and
chloride during the methanol based chlorine dioxide generation
process has been detd. Accordingly three distinct phases, namely the
initiation phase, the start-up phase, and the steady-state phase have
been identified. In the initiation phase, it was found that no chlorine
dioxide is generated while chlorous acid, chloride, and chlorine are
gradually formed. Chlorous acid is produced from the redn. of chloric
acid by methanol, and/or formaldehyde, and/or formic acid. The in-situ
generated chlorous acid is further reduced to hypochlorous acid.
Chloride is generated from chlorous acid in three possible reactions,
and it is a catalyst in the reaction between chlorine and chlorous acid,
which is responsible for the generation of chlorine-dioxide in the
methanol based ClO2 process. Due to an extremely low concn. of
chloride in the initiation phase, this reaction is not taking place, as a
result, no chlorine dioxide is generated. In the start-up phase, due to
the accumulation of chloride in the initiation phase, the reaction
between chlorine and chlorous acid becomes possible. As a result,
chlorine dioxide is now generated while chloride is formed from the
same reaction. Chlorate continues to be reduced to chlorous acid and
hypochlorous acid. In the steady-state phase, the concns. of both
chloride and chlorous acid are const. No chlorine is detected. Chlorine
dioxide is the only overall reaction product. Chloride is essentially a
"catalyst" in the chlorine dioxide generation cycle because it is
consumed in the redn. of chlorate, but reformed in the ClO2 generation
reaction between chlorine and chlorous acid. The reactions are
proposed as follows: HCl + HClO3 * HClO2 + HOCl; HOCl + HCl *
Cl2 + H2O; HClO3 + R * HClO2 + RO; Cl2 + 2 HClO2 * 2 ClO2 + 2 HCl.
Overall 2 HClO3 + R * 2 ClO2 + RO + H2O.
146. Effects of kappa variability on pulp properties.
Thomson, Sherry L.; Gustafson, Richard R. (Weyerhaeuser Company,
Seattle, WA, USA). Pulping Conf., Volume 1, 445-449. TAPPI Press:
Atlanta, Ga. (English) 1996. CODEN: 65XDAV. DOCUMENT TYPE:
Conference CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood
Products)
Although there have been documented cases of pulp uniformity issues
in the pulp and paper industry, there has not been a clear.
understanding of what effect nonuniformity has on pulp properties. The
purpose of this project was to understand this problem by comparing
pulp with variable kappa distributions with regard to bleachability and
mech. properties. Two mixts. with different kappa distributions were
compared to a uniform control pulp. These pulps were analyzed for
brownstock strength and fiber morphol. The pulps were also bleached
using an ECF and a TCF bleaching sequence. The pulps in this study
did not demonstrate significant differences between the mixts. and the
control pulp in strength or bleachability. There were some differences
in brownstock strength, but this difference was limited. Overall, the lab.
pulping and bleaching conditions used in this study were too mild to
produce the neg. effects that traditionally effect fiber strength;
consequently, the pulps in this study showed limited differences
between the mixts. and the control pulp. The intrinsic fiber strength was
maintained, and even with kappa variability, all of the pulps behaved
similarly.
147. Chlorine dioxide delignification practices in Canada.
Pryke, Douglas C.; Reeve, Douglas W. (Erin, ON, Can.). Pulping
Conf., Volume 1, 217-235. TAPPI Press: Atlanta, Ga. (English) 1996.
CODEN: 65XDAV. DOCUMENT TYPE: Conference CA Section: 43
(Cellulose, Lignin, Paper, and Other Wood Products)
The speed of implementation of complete replacement of chlorine
dioxide for chlorine in the first stage of chem. pulp bleaching, i.e.,
chlorine dioxide delignification, has been remarkable. Beginning in
1989, the prodn. of pulp using chlorine dioxide as the only
chlorine-contg. bleaching agent, often referred to as "Elemental
Chlorine Free" (ECF), has grown quickly. Almost ninety percent of
bleach plants in Canada will produce ECF in 1996, totaling 8.2 million
tonnes of bleached pulp. ECF pulp now accounts for almost seventy
percent of Canadian bleached chem. pulp prodn. Chlorine dioxide
delignification is rapidly becoming std. practice in the first stage of
bleached chem. pulp bleach plants. Optimum conditions, (based on
lab. bleaching) are well developed for: (1) minimizing cost; (2)
maximizing delignification; (3) maximizing pulp quality; and (4)
minimizing environmental impact. However, the practical conditions
utilized in actual mill scale prodn. of ECF pulps are not well
documented. This paper, based on the results of a survey of operating
conditions employed by Canadian bleached chem. pulp mills producing
ECF grades, describes mill practice for bleaching market pulp to high
brightness where chlorine dioxide is used in the first stage of bleaching.
Conditions for minimizing bleaching chem. cost and consumption are
identified for conventionally delignified softwood kraft pulps.
148. Reduced AOX and biological effects by modification of a mill
ClO2-stage.
Ljunggren, S.; Bergnor Gidnert, E.; De Sousa, F. (STFI, Stockholm
S-114 86, Swed.). Pulping Conf., Volume 1, 207-215. TAPPI Press:
Atlanta, Ga. (English) 1996. CODEN: 65XDAV. DOCUMENT TYPE:
Conference CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood
Products) Section cross-reference(s): 60
The first ClO2-stage in a modern OD(EPO)DD sequence for bleaching
of softwood kraft pulp at the Iggesund Paperboard Mill has been
modified by lowering the ClO2-charge, raising the pH-level and
introducing a more effective reinforced EPO-stage. The ClO2-charge
in the last D-stage was, however, slightly raised to maintain the same
high pulp brightness of 90 %. The two mixed D and EPO effluents
obtained before and after this modification were compared. The chem.
analyses included AOX (absorbable org. halogens), EOX (extractable
org. halogens), COD, TOC (total org. carbon), BOD7, chloroform,
chlorinated phenolics and extractives, etc. The bioassays consisted of
acute toxicity (Microtox), growth inhibition green algae (S.
capricornutum), survival and reprodn. (C. dubia), embryo-larval toxicity
with zebrafish (B. rerio) tests. Effluents were also tested in a
mini-model ecosystem. The chem. characterization study clearly
showed that the process modifications resulted in a redn. in the amt. of
chlorinated matter in the bleach plant effluent. An AOX redn. of 20 %
was obsd., while chlorinated acetic acids and chlorinated phenolic
compds. were reduced by 55 % and 35 % resp. For some of the test
methods used in the bioassay study, an improvement in effluent quality
was obsd.
149. An ECF sequence for the ALCELL process including an
ethanol-assisted ozone stage.
Ni, Yonghao; Van Heiningen, Adriaan R. P. (Univ. New Brunswick,
Fredericton, NB E3B 6C2, Can.). Tappi J., 81(4), 141-144 (English)
1998 TAPPI. CODEN: TAJODT. ISSN: 0734-1415. DOCUMENT
TYPE: Journal CA Section: 43 (Cellulose, Lignin, Paper, and Other
Wood Products)
An elemental chlorine-free (ECF) bleaching sequence was developed
for the ALCELL process (an ethanol-based autocatalyzed pulping
technol. for manuf. of organosolv pulp.). The sequence consists of an
efficient washing stage with an ethanol-water mixt. to further decrease
the residual lignin content, a high-consistency ozone bleaching stage
using a pH of 2, a 70% wt./wt. ethanol soln. for pulp impregnation, a hot
ethanol-water extn. stage, and two chlorine dioxide stages for final
brightening. This solvent-based bleaching process is compatible with
a recently developed ethanol-based solvent pulping technol. and shows
very limited carbohydrate degrdn. We found that the phys. and optical
properties of this ECF-bleached pulp are similar to or better than those
of the corresponding ODED bleached pulp. The advantage over the
ODED bleaching sequence is that the use of sodium hydroxide is
eliminated or decreased to a level that will not affect the economics or
environmental impact of an ethanol-water pulp mill that is operated
without a high-capital-cost caustic recovery system. The ozone-based
ECF bleaching sequence naturally fits into the ALCELL process.
150. D/Z or Z/D a large step toward cost reduction.
Johnson, Scott; Epiney, Michel; Homer, Gordon (USA). Int. Pulp
Bleaching Conf., Volume 2, 433-438. TAPPI Press: Atlanta, Ga.
(English) 1996. CODEN: 65XBAP. DOCUMENT TYPE: Conference
CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood Products)
The combination of ozone (Z) and ClO2 (D) in a single stage, the Z/D or
D/Z stage, in multistage pulp bleaching technols. is attractive in terms
of operating costs, capital costs, effluent quality, and final product
quality. Applicability of this bleaching stage in various pulping and
bleaching technols. is exemplified.