 |
|
第351---400篇 |
 |
||
|
|
第351---400篇 |
| |
||
351.
131:105010
Corrosion of steel in chlorine dioxide.
Song, Hong; Xi, Danli (Department of Environmental Science &
Engineering, China Textile University, Shanghai 200051, Peop. Rep.
China). Zhongguo Fangzhi Daxue Xuebao, 24(6), 83-86 (Chinese)
1998 Zhongguo Fangzhi Daxue. CODEN: ZFDXEQ. ISSN:
1000-1476. DOCUMENT TYPE: Journal CA Section: 55 (Ferrous
Metals and Alloys) Section cross-reference(s): 56
The corrosion behavior of steel utensils in ClO2 under different
conditions, such as concn., temp., pH, and contacting time, was
studied. At 25癈 and pH = 7, lower concn. ClO2 is a good disinfectant.
352.
131:103635
The impact of methanol-based by-products in chlorine dioxide solution
on pulp bleaching.
Van Heiningen, A. R. P.; Kang, G. K.; Reeve, D. W.; Weishar, K.; Earl,
P. F. (Dr. Jack Limerick McKenzie Pulp and Paper, Research and
Education Centre, UNB, Fredericton, NB, Can.). Pulp Pap. Can.,
100(4), 42-46 (English) 1999 Southam Inc. CODEN: PPCAAA. ISSN:
0316-4004. DOCUMENT TYPE: Journal CA Section: 43 (Cellulose,
Lignin, Paper, and Other Wood Products)
Studies were carried out to det. the fate and effects of the
MeOH-based byproducts formed during the generation of ClO2, when
that ClO2 soln. is used for pulp bleaching. The MeOH and HCOOH in
the ClO2 soln. had no effect on delignification efficiency or AOX
formation in the 1st 2 bleaching stages (DE). The MeOH formed by
lignin degrdn. in both the D0- and E1-stages is significantly higher than
that added with the ClO2 soln.. HCOOH is neither created nor
destroyed during pulp bleaching delignification. The addn. of MeOH
and HCOOH to ClO2 soln. produced mixed results with regard to the
BOD5 test. However, even in those expts. where the addn. of MeOH
and (or) HCOOH increased the bleach plant BOD5 load, the results did
not follow expected trends, and the changes were not statistically
significant.
353.
131:101528
Application of stable chlorine dioxide in malting and production of beer.
Shui, Huazhang; Wu, Jinchao; Yuan, Qing (Ningbo Jinshi Bar Co. Ltd.,
Ningbo, Peop. Rep. China). Niangjiu, (2), 80-81 (Chinese) 1999
Niangjiu Bianjibu. CODEN: NIANE6. ISSN: 1002-8110. DOCUMENT
TYPE: Journal CA Section: 17 (Food and Feed Chemistry)
Application of stable chlorine dioxide in malting and prodn. of beer was
studied. Antiseptic mechanism of stable chlorine dioxide was
introduced, and the application of stable chlorine dioxide in malting and
prodn. of beer for rinsing package, utensil, and equipment was studied.
The result showed that the method with stable chlorine dioxide as
antiseptic agent was effective, broad spectrum, and cheap, and was
suitable to apply in prodn. of beer.
354.
131:92264
Chlorine dioxide: effectiveness and epidemiological aspects.
Sansebastiano, G.; Zoni, R.; Mezzetta, S. (Facolta di Agraria,
Universita di Parma, Parma 43100, Italy). Ing. Ambientale, 27(4),
148-151 (Italian) 1998 C.I.P.A. Srl. CODEN: IGEABH. ISSN:
0394-5871. DOCUMENT TYPE: Journal CA Section: 61 (Water)
Section cross-reference(s): 4
An inactivation test was carried out on poliovirus 1, Coxsackievirus B3
and Echovirus 7, using ClO2 at various pHs and temps. A high virus
killing potential of ClO2 was obsd. and this was more active under
slightly alk. conditions and at >20*. The literature related to exptl. and
anal. epidemiol. studies carried out on humans was surveyed to
evaluate the toxic effects of ClO2 and ClO2-. This survey found no
evidence of any significant changes in hematol. parameters (red cells,
Hb, av.-cell vol., av. cell concn.) or in total cholesterol, HDL,
apolipoprotein B, metaHb and thyroid hormones.
355.
131:78966
Kinetics and a Revised Mechanism for the Autocatalytic Oxidation of
SCN- by ClO2.
Figlar, James N.; Stanbury, David M. (Department of Chemistry,
Auburn University, Auburn, AL 36849, USA). J. Phys. Chem. A,
103(29), 5732-5741 (English) 1999 American Chemical Society.
CODEN: JPCAFH. ISSN: 1089-5639. DOCUMENT TYPE: Journal
CA Section: 67 (Catalysis, Reaction Kinetics, and Inorganic Reaction
Mechanisms)
The aq. reaction of chlorine dioxide with excess thiocyanate is known to
be autocatalytic at pH 2. We find that under strongly acidic conditions
(>0.1 M HClO4) it is pseudo-first-order with respect to [ClO2]. Under
these conditions, the rate law is -d[ClO2]/dt = (2k1 +
2k2[H+])[ClO2][SCN-], with 2k1 = 0.42 M-1 s-1 and 2k2 = 0.52 M-2 s-1 at
25 癈 and m = 1 M (LiClO4). Effective activation parameters in 1 M
HClO4 are DHG = 66.5 kJ/mol and DSG = -26.3 J/mol for the temp. range
13.4-52.2 癈. Reaction products were identified by ion chromatog. and
ion-selective electrodes, which allowed a verification of the
stoichiometry, 6ClO2 + 5SCN- + 8H2O * 6Cl- + 5CN- + 5SO42- + 16H+.
Direct evidence for a reaction intermediate, thiocyanogen, was
obtained through careful anal. of multiwavelength rapid scanning data.
This intermediate provides a reactive autocatalytic species OSCN- via
hydrolysis equil., and this equil. was found to be important to
simulations and fits to raw data. A 14-step mechanism is employed for
these fits and simulations, allowing a more thorough description of the
reaction system; this mechanism successfully reproduces both the full
rate law under pseudo-first-order conditions and the autocatalytic
behavior at pH 2.
356.
131:77715
Application of stabilized chlorine dioxide removal of phenol from
wastewater.
Feng, Meiqing; Shi, Lanxiang; Li, Hui (Dep. Chemical and
Pharmaceutical Engineering, Hebei Univ. Science and Technology,
Shijiazhuang 050051, Peop. Rep. China). Hebei Keji Daxue Xuebao,
20(1), 14-16, 46 (Chinese) 1999 Hebei Keji Daxue Xuebao Bianjibu.
CODEN: HKDXFY. ISSN: 1008-1542. DOCUMENT TYPE: Journal
CA Section: 60 (Waste Treatment and Disposal)
By expts., the effects of ClO2 to remove phenol from the std. phenol
soln. under different conditions were investigated. The optimal
conditions for meeting the std. of waste removal include for reaction
temp. 25癈, the ClO2 vol. fraction 1/10,000 and reaction time 3-4 h or
1.5/10,000 and 2-3 h; and for the temp. at 35癈, 1/10 000 and 2-3 h,
resp. Thus, the waste water contg. phenol does not require
pretreatment and may simply adjust the vol. fraction of ClO2 and the
time of reaction according to the reaction temp. Using above result the
actual effect for the ClO2 to remove the phenol in waste water was
investigated. Using ClO2 to remove the phenol is suitable for the lower
vol. fraction phenol in waste water and the tertiary treatment of the
higher phenol waste water.
357.
131:75742
Process for the production of chlorine dioxide.
Fredette, Maurice C. J.; Costa, Mario L. (Sterling Canada Inc., USA).
Can. Pat. Appl. CA 2226651 AA 13 Jul 1998, 20 pp. (English).
(Canada). CODEN: CPXXEB. CLASS: ICM: C01B011-02.
APPLICATION: CA 1998-2226651 12 Jan 1998. PRIORITY: US
1997-35488 13 Jan 1997. DOCUMENT TYPE: Patent CA Section: 49
(Industrial Inorganic Chemicals) Section cross-reference(s): 43
Chlorine dioxide is produced from sodium chlorate and a hydrochloric
acid in the presence of a significant amt. (at least about 22 g/L) of
sodium dichromate to improve the efficiency of chlorine dioxide prodn.
The process is integrated with a chlorate cell producing sodium
chlorate for the chlorine dioxide generation from sodium chloride
byproduct from a chlorine dioxide generating process. The integration
is effected to maintain a pH of 6-7 in the chlorate cell in the presence of
2-7 g/L of sodium dichromate.
358.
131:75127
Enzyme bleaching following kraft/anthraquinone or
kraft/anthraquinone/polysulfide pulping.
Nemeth, A.; Jameel, H.; Joyce, T. W.; Kovacs, I.; Erdelyi, D. J.
(Department of Pulp and Paper Science, University of Sopron, Sopron,
Hung.). Cellul. Chem. Technol., 32(3-4), 291-298 (English) 1998
Editura Academiei Romane. CODEN: CECTAH. ISSN: 0576-9787.
DOCUMENT TYPE: Journal CA Section: 43 (Cellulose, Lignin, Paper,
and Other Wood Products) Section cross-reference(s): 7, 16
The effect of enzyme (xylanase) pretreatment prior to a D(EOP)D
bleach sequence for kraft, kraft/anthraquinone and
kraft/anthraquinone/polysulfide pulps has been investigated. Lower
(about 23) and higher (about 30) kappa no. pulps have been used for
the expts. The brightness results were in the focus. It was established
that the enzyme had the greatest effect on pulps with lower kappa no.,
while, amongst the lower kappa pulps, the kraft/AQ/PS pulp had been
the most sensitive to the enzyme pretreatment.
359.
131:63905
Vanishingly slow kinetics of the ClO2/Cl- reaction: its questionable
significance in nonlinear chlorite reactions.
Stanbury, David M.; Figlar, James N. (Department of Chemistry,
Auburn University, Auburn, AL, USA). Coord. Chem. Rev., 187,
223-232 (English) 1999 Elsevier Science S.A. CODEN: CCHRAM.
ISSN: 0010-8545. DOCUMENT TYPE: Journal; General Review CA
Section: 67 (Catalysis, Reaction Kinetics, and Inorganic Reaction
Mechanisms)
A review with 29 refs.; there is considerable disagreement regarding
the rate of the aq. reaction 2ClO2+Cl-+H2O瓾ClO2+ClO2-+HOCl.
Bray's early (1906) measurements indicate a third-order rate const. of
1*10-3 M-2 s-1 at 60癈, while recent kinetic modeling studies of chlorite
oscillators use rate consts. ranging from 5*101 to 8*107 M-2 s-1 at
25癈. We report attempts to make direct measurements on the
reaction at 25癈. The reaction is very slow and photosensitive: in 0.1
M HCl with 0.8 mM ClO2 less than 5% of the ClO2 is consumed in 3 h,
and in 0.01 M HClO4/1 mM NaCl with 0.3 mM ClO2 less than 10% is
consumed in 2 wk. Free energy calcns. indicate that the reaction has
an equil. const. too small for the reaction to occur by itself. In principle
the reaction can be driven by the addn. of product scavengers.
Moreover, if appropriate scavengers are present to remove the
purported intermediates ClClO2 and ClO2- then the reaction could have
the sought third-order rate law. Support for a finite but low rate const.
(k3.8*10-5 M-2 s-1) for this process comes from a consideration of a
prior report on the kinetics of the reverse reaction in view of the
principle of microscopic reversibility. Finally, ab initio calcns. on
ClClO2, an intermediate in the reaction, lead to an upper limit of
1.2*10-5 M-2 s-1; within the uncertainty in the hydration energy of ClClO2,
this result is in agreement with the lower limit given above. Thus, while
an accurate value for the rate const. at 25癈 is not yet in hand, it is
clearly orders of magnitude less than has been used in several recent
kinetic simulations.
360.
131:62501
Taking the hazard out of Cl and ClO2 exposures in a kraft pulp mill. An
extensive study looked at long-term and peak exposures in the
chemical preparation and bleach plant study.
Svirchev, Laurence; Astrakianakis, George; Band, Pierre; Bert, Joel;
Janssen, Robert; Le, Nhu; Tang, Clement (Prevention Division, the
British Columbia Cancer Agency and Workers' Compensation Board
of, Vancouver, BC, Can.). Pulp Pap. Can., 100(3), 19-20,22-23
(English) 1999 Southam Inc. CODEN: PPCAAA. ISSN: 0316-4004.
DOCUMENT TYPE: Journal CA Section: 59 (Air Pollution and Industrial
Hygiene) Section cross-reference(s): 43
Several sources of excessive worker exposure to ClO2 and Cl2 in the
chem. prepn. and bleach plant areas of a pulp mill due to gassings in a
day-to-day prodn. work and during a process upset were identified and
quantified. Continuous personal monitoring by data-logging
electrochem. sensors permitted this data to be recorded. These high
levels have not been previously obsd. due to the limitations of
older-generation industrial hygiene sampling equipment. In light of the
above findings and the current knowledge of the health effect of
gassings upon the respirator systems, it is recommended that: (1)
hygiene sampling programs be conducted in such a manner that peak
exposures workers encounter are being registered, (2) local exhaust
ventilation should be installed and checked for proper function, (3)
personal monitoring instrumentation, such as electrochem. sensors
equipped with alarms, should be used, (4) education of the work force
should be increased, (5) prospective spirometry programs should be
started, and (6) further research is needed to det. how respiratory
function is affected by multiple gassings from pulp mill hazardous
gases.
361.
131:58462
EPR study of the reaction of C60 with chlorine dioxide: experimental
evidence for the formation of the C60 radical cation.
Sokolov, Viatcheslav I.; Bashilov, Vasily V.; Timerghazin, Qadir K.;
Avzyanova, Elena V.; Khalizov, Alexey F.; Shishlov, Nikolay M.;
Shereshovets, Valeri V. (A. N. Nesmeyanov Institute of Organoelement
Compounds, Russian Academy of Sciences, Moscow 117813,
Russia). Mendeleev Commun., (2), 54-55 (English) 1999 Russian
Academy of Sciences. CODEN: MENCEX. ISSN: 0959-9436.
DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic
Chemistry)
The interaction of ClO2 with fullerene C60 affords a brown ppt., the ESR
spectrum of which exhibits an asym. singlet signal (g = 2.0029, DHpp =
0.2 mT) tentatively assigned to the fullerene radical cation.
362.
131:53220
Different valency chlorine species analysis by non-suppressed
ion-chromatography with double cell quartz crystal detector.
Chen, Po; Wei, Wan-Zhi; Yao, Shou-Zhuo (New Materials Research
Institute, Hunan University, Changsha 410082, Peop. Rep. China).
Talanta, 49(3), 571-576 (English) 1999 Elsevier Science B.V.
CODEN: TLNTA2. ISSN: 0039-9140. DOCUMENT TYPE: Journal CA
Section: 79 (Inorganic Analytical Chemistry) Section
cross-reference(s): 61
A nonsuppressed ion-chromatog. assay combined with a novel double
cell quartz crystal (DCQC) detector is developed for anal. of different
valency Cl species including chlorite, chloride, chlorate, hypochlorite.
The retention characteristics of the anions are discussed. The
chromatog. system involves the use of a Shimadzu Shim-pack IC-Al
anion anal. column with 0.5 mM K acid phthalate (KHP), pH 6.7, as a
mobile phase. The DCQC detector has a low temp. coeff. and a high
conductance sensitivity independent of the background from 7.2 to
2500 mS. The anal. of sample is completed without the use of an ion
suppression device.
363.
131:51280
Infrared Spectroscopic and ab Initio Study of HOOClO2.
Svensson, Thomas; Nelander, Bengt; Bernhardsson, Anders;
Karlstroem, Gunnar (Chemical Physics Chemical Center, Lund
S-22100, Swed.). J. Phys. Chem. A, 103(23), 4432-4437 (English)
1999 American Chemical Society. CODEN: JPCAFH. ISSN:
1089-5639. DOCUMENT TYPE: Journal CA Section: 73 (Optical,
Electron, and Mass Spectroscopy and Other Related Properties)
Section cross-reference(s): 74
HOOClO2 was produced by addn. of H atoms to a mixt. of O2 and OClO
on the surface of growing Ar matrixes at 17 K. The compd. was
identified by IR spectroscopy using the H to D and 18O2 and 16,18O2
spectral shifts. The matrixes were irradiated with the full radiation from
a 300-W Xe lamp. HOOClO2 was eliminated by the irradn., but the
authors were unable to identify the photodecompn. product. Ab initio
calcns. show that HOO binds to OClO with a bond strength
intermediate between a van der Waals interaction and a covalent bond.
364.
131:48853
Chemical aspects of disinfection.
Riganti, Vincenzo; Conio, Osvaldo (Dip. Chim. Generale, Univ. Pavia,
Pavia 27100, Italy). Ing. Ambientale, 27(10), 474-488 (Italian) 1998
C.I.P.A. Srl. CODEN: IGEABH. ISSN: 0394-5871. DOCUMENT
TYPE: Journal; General Review CA Section: 61 (Water)
A review, with ~12 refs., on processes for disinfection of drinking
waters, including management of treatment plants and economic
issues as well as treatment of residues. Processes based on use of
chlorine and its compds., formation of organochlorine derivs.,
alternatives, e.g., use of ClO2, O3, chloramines, UV irradn., advanced
oxidn. processes, and use of peracetic acid are discussed.
365.
131:44046
Preservation of cereals.
Ogawa, Katsutoshi; Shibata, Atsushi (Chisso Corp.; National
Federation of Agricultural Co-Operative Assoc., Japan). Jpn. Kokai
Tokkyo Koho JP 11168969 A2 29 Jun 1999 Heisei, 4 pp. (Japanese).
(Japan). CODEN: JKXXAF. CLASS: ICM: A01F025-00. ICS:
A23B009-00. APPLICATION: JP 97-362039 11 Dec 1997.
DOCUMENT TYPE: Patent CA Section: 17 (Food and Feed
Chemistry)
Chlorine dioxide gas or air contg. chlorine dioxide is passed through
containers of cereals such as rice, keeping the concn. of chlorine
dioxide at 10-500 ppm. for 10-240 min.
366.
131:40954
Amine-containing biocidal compositions containing a stabilized chlorite
source.
Wellinghoff, Stephen T.; Kampa, Joel J. (Southwest Research Institute,
USA). U.S. US 5914120 A 22 Jun 1999, 40 pp., Cont.-in-part of U.S.
Ser. No. 426,039, abandoned. (English). (United States of America).
CODEN: USXXAM. CLASS: ICM: A01N025-08. NCL: 424406000.
APPLICATION: US 97-924684 5 Sep 1997. PRIORITY: US
95-426039 5 Jun 1995. DOCUMENT TYPE: Patent CA Section: 5
(Agrochemical Bioregulators)
A composite for retarding, killing, preventing or controlling microbiol.
contamination includes a hydrophilic material contg. an a-amino ether,
a-amino alc. or a-amino ester, a chlorite salt, and a hydrophobic
material contg. an acid-releasing agent. The hydrophilic and
hydrophobic materials are adjacent and free of water, and the
hydrophilic material is capable of generating and releasing chlorine
dioxide after hydrolysis of the acid-releasing agent.
367.
131:35537
ECF technology: The chlorine dioxide generation system of the future.
Cowley, Gerald; Znajewski, Teresa (Sterling Pulp Chemicals, Ltd.,
Can.). Proc. Annu. Conf. West. Can. Water Wastewater Assoc.,
50th(Vol. 2), 510-519 (English) 1998 Western Canada Water and
Wastewater Association. CODEN: PWWAER. DOCUMENT TYPE:
Journal CA Section: 61 (Water) Section cross-reference(s): 47, 60
ECF technologies will allow municipalities and other users to realize
the benefits of ClO2, such as its effectiveness in deactivating
Cryptosporidium and Giardia, while meeting EPA guidelines in
disinfection byproducts (e.g. chlorite ion, etc.) and also to produce and
apply the ClO2 dose in an effective and economic manner.
368.
131:35527
Control of mutagenicity of nonvolatile organic pollutants in drinking
water.
Wang, Jia-ling; Tang, Fei; Gu, Kang-ding; Wang, Ya-zhou; Zhang,
Shui-bing (Institute of Environmental Medicine, Tongji Medical
University, Wuhan 430030, Peop. Rep. China). Zhongguo Huanjing
Kexue, 19(2), 114-118 (Chinese) 1999 Zhongguo Huanjing Kexue
Bianji Weiyuanhui. CODEN: ZHKEEI. ISSN: 1000-6923.
DOCUMENT TYPE: Journal CA Section: 61 (Water) Section
cross-reference(s): 4
Measures for decreasing mutagenicity of drinking water were studied.
Biofilm pretreatment of raw water resulted in av. redn. of algae, aquatic
humic acids and TOC by 68.2, 23.9 and 37.2%, resp. The Cl
consumption of water decreased by 50% and the mutagenicity of
drinking water decreased by 30%. Waters treated by different
disinfectants showed a consistent pattern of mutagenic potency, with
decreasing activity in the order Cl>ClO2>Cl+ClO2>raw water. The
effects of inactivation of HAV, poliovirus and E. coli bacteriophage f2
treated by disinfectants indicated that the combination of Cl and ClO2
was one or several times higher than Cl alone. The amt. of CHCl3 in
the waster treated with Cl+ClO2 decreased by 91.5-96.5% compared
with Cl and mutagenicity redn. was 27.6%.
369.
131:33131
Pulp bleaching effect and ionization rate of chlorine dioxide by
additives and various pH conditions (I). Ionization of ClO2 and formation
of chlorate in pulp bleaching.
Yoon, Byung-Ho; Wang, Li-Jun; Kim, Yong-Sik (S. Korea). Palpu,
Chongi Gisul, 30(3), 1-6 (Korean) 1998 Korea Technical Association of
the Pulp and Paper Industry. CODEN: PCGIDY. ISSN: 0253-3200.
DOCUMENT TYPE: Journal CA Section: 43 (Cellulose, Lignin, Paper,
and Other Wood Products)
Elementally chlorine free (ECF) bleaching will be superior than totally
chlorine free (TCF) bleaching, not only because they have no significant
difference in effluent toxicity, but also those pulps bleached by ECF
have higher brightness, strength, yield, etc., over those by TCF. The
chem. of chlorine dioxide decompn. and ionization, both in water soln.
and in pulp slurry, was studied. Special attention was paid to chlorate
ion because there have been controversies as how it is formed and
what its behavior to the end pH of pulp bleaching is. As a result, during
ionization of chlorine dioxide with water, both chlorate and chlorite were
found to increase with increasing pH, but during ionization with pulp,
chlorite was found to increase with end pH while chlorate decreased
with increasing end pH. In the case of ionization with water, the
disproportion equation 2ClO2 + OH- * H2O + ClO3-+ ClO2- was thought
to become the main reaction with the increasing pH, while in the case
of ionization with pulp, the reaction HClO + ClO2- * H+ + Cl- + ClO3-
was the main reaction contributing to the formation of chlorate. Based
on this above opinion, the contrary results of chlorine dioxide ionization
from different researchers were discussed and explained.
370.
131:25633
Reduction Potentials of SO3*-, SO5*-, and S4O6*3- Radicals in Aqueous
Solution.
Das, Tomi Nath; Huie, Robert E.; Neta, P. (Physical and Chemical
Properties Division, National Institute of Standards and Technology,
Gaithersburg, MD 20899-8381, USA). J. Phys. Chem. A, 103(18),
3581-3588 (English) 1999 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): 68, 72
Redn. potentials of the SO3*-, SO5*-, and S4O6*3- radicals in aq. solns.
are measured by pulse radiolysis at 294 K. These radicals are
produced by reaction of 稯H or N3* radicals with sulfite,
peroxymonosulfate, and thiosulfate anions, resp. The potentials for the
couples SO3*-/SO32- and SO5*-/SO52- are detd. from equil. consts. with
three ref. couples of the phenoxyl/phenoxide type, i.e., those derived
from phenol, 3-cresol, and tyrosine. The potential for PhO*/PhO- is
redetd. against ClO2*/ClO2- and confirms the published value. The
potentials for the other two phenols are detd. against PhO*/PhO-. The
potential for the SO3*-/SO32- couple is found to be 0.73 * 0.01 V vs
NHE. The potential for SO5*-/SO52- is found to be 0.81 * 0.02 V. The
redn. potential of the radical formed from the one-electron oxidn. of
thiosulfate, which exhibits a lmax at 375 nm, is also detd. This radical
was identified before as either the monomeric S2O3*- or the dimeric
S4O6*3-. Equil. measurements for this species, using N3* and the
4-cyanophenoxyl radical as refs., support the dimeric assignment and
yield a value of 1.07 * 0.03 V for the redn. potential for the couple
S4O6*3- /2S2O32-.
371.
131:23584
Disinfecting objects with chlorine dioxide.
Littlejohn, Graham MacCallum (UK ). Brit. UK Pat. Appl. GB 2329589
A1 31 Mar 1999,24 pp. (English). (United Kingdom). CODEN:
BAXXDU. CLASS: ICM: A61L002-20. APPLICATION: GB 98-20725
24 Sep 1998. PRIORITY: GB 97-20249 24 Sep 1997. DOCUMENT
TYPE: Patent CA Section: 63 (Pharmaceuticals)
A disinfection process for objects such as dental impressions
comprise placing an object to be disinfected into a sealable container
together with a source of chlorine dioxide, adding a reagent capable of
liberating the chlorine dioxide and sealing the container so that
liberated chlorine dioxide disinfects the objects. The source of chlorine
dioxide may be chlorine dioxide soln. provided as an absorbent fabric
wettened with the soln., the fabric being wrapped around the object to
be disinfected. Preferably the container is a transparent plastic bag. A
kit is provided for carrying out the method. Dental impressions were
wrapped in a cloth soaked in 5% chlorine dioxide soln. and placed in a
polyethylene bag. Then 0.5 g of activator granules contg. 80% sodium
hydrogen sulfate and 20% calcium hypochlorite were then poured into
the bag, and the bag was sealed and shaken to bring the granules into
contact with wettened cloth. The bag was then left for an h at room
temp. to allow prodn. of chlorine dioxide gas.
372.
131:23147
Determination of concentration of a compound in a multiple component
fluid.
Tsai, Lee-Shin; Hernlem, Bradley J.; Huxsoll, Charles C. (United States
Dept. of Agriculture, USA). PCT Int. Appl. WO 9930142 A1 17 Jun
1999, 39 pp. DESIGNATED STATES: W: AL, AM, AT, AU, AZ, BA,
BB, BG, BR, BY, CA, CH, CN, CZ, DE, DK, EE, ES, FI, GB, GD, GE,
GH, GM, HR, HU, ID, IL, IN, 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, UZ, VN, YU, ZW, AM,
AZ, BY, KG, KZ, MD, RU, TJ, TM; RW: AT, BE, BF, BJ, CF, CG, CH,
CI, CM, CY, 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: G01N027-26. ICS:
G05B001-00. APPLICATION: WO 98-US26097 9 Dec 1998.
PRIORITY: US 97-69152 9 Dec 1997. DOCUMENT TYPE: Patent CA
Section: 61 (Water)
Methods and app. are provided for accurately detg. the concn. of a
selected compd. or compds. in a multiple component fluid, by reducing
or eliminating the interference of non-selected compds. in the fluid. In
the method of the invention, the concn. of one or more compds. in a test
sample fluid which contains at least two compds. is detd. using at least
two amperometric or potentiometric membrane sensors which have
different specificities and which were calibrated to det. the individual
response-to-concn. ratio of each sensor to the selected compd. and
non-selected or interfering compd. The concn. of the selected compd.
is detd. by simultaneously measuring the response of each membrane
sensor to the test sample and computing the concn. of the selected
compd. using the simultaneously measured responses to the test
sample fluid and the calibrated responses of the sensors.
373.
131:20966
Chlorine peroxide water production kit, chlorine peroxide water
precursor composition, and production of chlorine peroxide water.
Ogawa, Katsutoshi; Oyama, Masako (Chisso Corp., Japan). Jpn.
Kokai Tokkyo Koho JP 11157805 A2 15 Jun 1999 Heisei, 7 pp.
(Japanese). (Japan). CODEN: JKXXAF. CLASS: ICM: C01B011-02.
ICS: A61L002-18. APPLICATION: JP 97-343615 1 Dec 1997.
DOCUMENT TYPE: Patent CA Section: 49 (Industrial Inorganic
Chemicals) Section cross-reference(s): 60
This ClO2-contg. water prodn. kit comprises a chlorite soln., an acid,
and chlorides of alkali metals and/or alk. earth metals: and the chlorite
soln. and the acid are kept from each other. The ClO2 water precursor
compn. is produced by statically adding the chlorite soln. to a mix. soln.
contg. the alkali and/or alk. earth chlorides, the acid, and water.
ClO2-contg. water is produced by keeping the precursor compn. still for
30 s to 10 min. and then well mixing the compn. ClO2-contg. water
having high purity and useful for disinfection, deodorization, and
discoloration can easily, safely, and timely produced on site.
374.
131:18210
Efficacy of chlorine dioxide gas as a sanitizer for tanks used for aseptic
juice storage.
Han, Y.; Guentert, A. M.; Smith, R. S.; Linton, R. H.; Nelson, P. E.
(Department of Food Science, Purdue University, West Lafayette, IN
47907-1160, USA). Food Microbiol., 16(1), 53-61 (English) 1999
Academic Press. CODEN: FOMIE5. ISSN: 0740-0020. DOCUMENT
TYPE: Journal CA Section: 17 (Food and Feed Chemistry)
An aseptic tank model system was used to study the efficacy of
chlorine dioxide (ClO2) gas as a potential sanitizing agent for com.
epoxy-lined juice storage tanks. Selected spoilage micro-organisms
(Lactobacillus buchneri, Leuconostoc mesenteroides, Eurotium spp.,
Penicillium spp, Candida spp. and Saccharomyces cerevisiae) were
surface inoculated on to epoxy-coated stainless steel strips, placed in
the model tank and subjected to different ClO2 gas treatments. The
varied treatment conditions consisted of 2-14 mg L-1 ClO2 gas, 50-98%
relative humidity, 5-120 min exposure time, and temps. ranging from
9-31癈. L. buchneri was used as the target microorganism and was
found to be most resistant to selected ClO2 gas treatments, followed by
L. mesenteroides, followed by the yeasts and molds studied.
Inactivation of L. buchneri and L. mesenteroides increased with greater
concn. of ClO2 gas, higher holding temp., higher relative humidity, and
more exposure time. Under the conditions of this study, all the selected
microorganisms could be completely inactivated, resulting in a
sterilized surface. The recommended treatments for assuring sterility
were 10 mg L-1 ClO2 gas for an exposure time of 30 min coupled with
(a) high relative humidity (>90%) and holding temps. between 9 and
28癈, or (b) high holding temps. (25-28癈) and relative humidity above
69%. (c) 1999 Academic Press.
375.
131:13046
Determination of effective chlorine content in chlorine dioxide
disinfectant.
Tao, Jiye; Ding, Zhangrong (Chongqing Cement Plant, Chungking
400060, Peop. Rep. China). Lihua Jianyan, Huaxue Fence, 35(2), 90
(Chinese) 1999 Jixie Gongyebu Shanghai Cailiao Yanjiuso. CODEN:
LJHFE2. ISSN: 1001-4020. DOCUMENT TYPE: Journal CA Section:
79 (Inorganic Analytical Chemistry) Section cross-reference(s): 10
A method for the detn. of effective Cl content in ClO2 disinfectant was
presented. I2 was released from the reaction of the disinfectant with KI
in acid condition, and titrated by Na2S2O3. Free Cl2 was masked by
glycine. The relative derivation was 2.6-3.6% and the recovery
88.4-96.6%.
376.
131:9355
Water quality impacts of pure chlorine dioxide pretreatment at the
Roanoke County (Virginia) water treatment plant.
Ellenberger, C. S.; Hoehn, R. C.; Gallagher, D. L.; Knocke, W. R.; Via,
Charles E., Jr.; Wiseman, E. V.; Benninger, R. W.; Rosenblatt, A.
(Black and Veatch, Greenville, SC 29607, USA). Proc. - Annu. Conf.,
Am. Water Works Assoc., (Vol. D, Water Quality), 131-157 (English)
1998 American Water Works Association. CODEN: PWACDO.
ISSN: 0360-814X. DOCUMENT TYPE: Journal CA Section: 61
(Water)
The fate of ClO2 following its addn. at a water treatment plant (WTP)
and development of byproducts in the WTP and distribution system
were studied. Specific objectives were: document changes in ClO3,
chlorites (ClO2-), and chlorates (ClO3-) concns. throughout the Roanoke
County, Virginia, WTP and distribution system following ClO2
pretreatment of raw water; evaluate the effectiveness of granular
activated C in post-filter contactors for ClO2- removal; and det. the
extent to which ClO2 reforms in the distribution system following
post-chlorination of treated water and concns. assocd. with customer
odor complaints. Results are reported.
377.
130:356805
Impact of Giardia inactivation requirements on ClO2 by-products.
Hofmann, R.; Andrews, R. C.; Ye, Q. (Department of Civil Engineering,
University of Toronto, Toronto, ON M5S 1A4, Can.). Environ. Technol.,
20(2), 147-158 (English) 1999 Selper Ltd. CODEN: ENVTEV. ISSN:
0959-3330. DOCUMENT TYPE: Journal CA Section: 61 (Water)
Chlorite, chlorate, and trihalomethane (THM) formation was measured
following the disinfection of drinking water using chlorine dioxide either
alone, or followed by chlorine or monochloramine. Chlorine dioxide
doses were selected to provide a range of Giardia inactivation levels
as calcd. using CT values (disinfectant concn. x contact time)
presented in the US Surface Water Treatment Rule. Expts. were
conducted at bench-scale in batch reactors, using water obtained from
two river sources. Dose requirements did not vary greatly when
disinfecting at 1 vs. 25*, since the higher CT requirements in the cold
(due to slower disinfection kinetics) were offset by greater chlorine
dioxide stability at low temp. Higher doses were required at pH 9
compared to pH 6, due to chlorine dioxide disproportionation at the
higher pH. Greater formation of chlorite and chlorate was obsd. at the
higher pH. Temp. exerted a relatively small effect on chlorite and
chlorate formation, following the trend obsd. for required dose. When
free chlorine was applied as a secondary disinfectant following primary
disinfection with chlorine dioxide, subsequent chlorite concns.
decreased at pH 6, but not at pH 9, suggesting that hypochlorous add,
and not hypochlorite, was responsible for the oxidn. of chlorite. THM
formation at pH 9 arising from secondary chlorination was reduced by
up to 30 mg L-1 due to prior application of chlorine dioxide at concns.
corresponding to as low as 0.5 log Giardia inactivation.
378.
130:356532
Disinfectants for activated sludge used in organic wastewater
treatment.
Kosho, Kenta; Suzuki, Kazuyoshi; Koyama, Osamu; Yamachi, Hisashi;
Asakawa, Taketoshi (Kankyo Engineering Co., Ltd., Japan). Jpn.
Kokai Tokkyo Koho JP 11147801 A2 2 Jun 1999 Heisei, 7 pp.
(Japanese). (Japan). CODEN: JKXXAF. CLASS: ICM: A01N025-00.
ICS: A01N025-30; A61L002-16; C02F003-12; C02F011-00.
APPLICATION: JP 97-299600 17 Oct 1997. PRIORITY: JP 97-265096
12 Sep 1997. DOCUMENT TYPE: Patent CA Section: 60 (Waste
Treatment and Disposal)
Recycle activated sludges used in org. wastewater treatment are
disinfected by dosing with a disinfectant contg. *1 compds. selected
from cationic or amphoteric surfactants, Cl compds. (esp., ClO2),
phenols, nitrofurans, alcs., nitroalkylthiol compds., aldehydes, protease,
dithiocarbamates, glucanase, amylase, magnesium
monoperoxyphthalate in a mixing tank, and then reacting with the
recirculating water in an aeration tank.
379.
130:353849
Method of converting chlorine dioxide present in a gaseous stream
from a pulp bleach plant by irradiation to chlorine.
Tenney, Joel (EKA Chemicals, Inc., USA). U.S. US 5908532 A 1 Jun
1999, 4 pp. (English). (United States of America). CODEN: USXXAM.
CLASS: ICM: D21C011-06. NCL: 162029000. APPLICATION: US
96-740533 30 Oct 1996. DOCUMENT TYPE: Patent CA Section: 43
(Cellulose, Lignin, Paper, and Other Wood Products)
A method for destroying ClO2 includes irradiating ClO2 to effect
conversion to chlorine and then reacting at least part of the resulting
chlorine to form chloride.
380.
130:353848
Bleaching of chemical pulp and treatment with chelating agents.
Jakara, Jukka; Aksela, Reijo; Paren, Aarto; Renvall, Ilkka (Kemira
Chemicals Oy, Finland). PCT Int. Appl. WO 9925919 A1 27 May 1999,
14 pp. DESIGNATED STATES: W: AL, AM, AT, AU, AZ, BA, BB, BG,
BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, GB, GD, GE, GH, GM,
HR, 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,
CY, 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: D21C009-16. ICS:
D21C009-10; D21C009-14. APPLICATION: WO 98-FI887 13 Nov
1998. PRIORITY: FI 97-4221 13 Nov 1997. DOCUMENT TYPE:
Patent CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood
Products)
The pulp is delignified and/or bleached with ClO2 or with a combination
of ClO2 and a per-compd., and addnl. the pulp is chelated in order to
bind heavy metals, such as Fe, Mn and/or Cu, to a chelate complex.
The chelate complex is selected from the group made up of
N,N-bis-[(1,2-dicarboxyethoxy)ethyl]amine,
N,N-bis[(1,2-dicarboxyethoxy)ethyl]aspartic acid and
N,N,N-tris[(1,2-dicarboxyethoxy)ethyl]amine, and the alkali metal and
earth-alkali metal salts of these, and the chelating treatments are
carried out simultaneously by combining the chelating chem. with the
pulp in the same bleaching stage as ClO2.
381.
130:343251
Structure and Bonding of Chlorine Oxides and Peroxides: ClOx, ClOx-
(x = 1-4), and Cl2Ox (x = 1-8).
Beltran, Armando; Andres, Juan; Noury, Stephane; Silvi, Bernard
(Departament de Ciencies Experimentals, Universitat Jaume I,
Castello 12080, Spain). J. Phys. Chem. A, 103(16), 3078-3088
(English) 1999 American Chemical Society. CODEN: JPCAFH.
ISSN: 1089-5639. DOCUMENT TYPE: Journal CA Section: 65
(General Physical Chemistry) Section cross-reference(s): 73
The structural and bonding properties of the chlorine oxides and
peroxides ClOx, ClOx-, (x = 1-4) and Cl2Ox (x = 1-8) in their ground state
have been investigated with the hybrid spin unrestricted and spin RHF
d. functional method. The equil. structures of the most stable isomers in
each stoichiometry have been detd. It is found that the di-chlorine
oxides avoid the formation of a Cl-Cl bond, and therefore have either
an oxo or peroxo structure. The calcd. vibrational harmonic frequencies
are in good agreement with the available gas phase or matrix isolation
IR data. The calcd. adiabatic electron affinities of the mono-chlorine
species are, resp., 2.23, 2.14, 4.07, and 5.1 eV for ClO, ClO2, ClO3,
and ClO4. The reaction enthalpies of the possible channels leading to
the formation of di-chlorine oxides and peroxides Cl2Ox from
mono-chlorine oxide fragments are reported and discussed. A
comparative discussion of the bonding in these species has been
carried out on the basis of the topol. anal. of the electron localization
function (ELF). It is found that the odd electron of the mono-chlorine
species is distributed on the oxygen and chlorine lone pairs. The weak
populations of the ClO bond basins and the absence of spin d. within
them leads to discarding a picture in which three electrons are involved
in the ClO bond. The localization of the spin d. in the mono-chlorine
oxides dets. the reactive center: oxygen for ClO and ClO4, chlorine for
ClO2 and ClO3. The formation of the di-chlorine oxides and peroxides
from the mono-chlorinated species follows the two following rules: (i)
the formation of a Cl-Cl bond never yields the most stable isomer, (ii)
the chem. bond linking the two fragments is formed between their
reactive centers provided rule (i) is satisfied.
382.
130:343189
Electron affinities of the oxides of aluminum, silicon, phosphorus, sulfur,
and chlorine.
Brinkmann, Nicole R.; Tschumper, Gregory S.; Schaefer, Henry F., III
(Center for Computational Quantum Chemistry, University of Georgia,
Athens, GA 30602-2556, USA). J. Chem. Phys., 110(13), 6240-6245
(English) 1999 American Institute of Physics. CODEN: JCPSA6.
ISSN: 0021-9606. DOCUMENT TYPE: Journal CA Section: 65
(General Physical Chemistry)
The adiabatic electron affinities of five second row atoms (Al, Si, P, S,
Cl) and their monoxides and dioxides were detd. using six different d.
functional or hybrid Hartree-Fock/d. functional methods. The 15
species selected form a convenient closed set for which reliable exptl.
electron affinities exist for 13 of the species. Zero-point vibrational
energy cor. electron affinities are also reported. Equil. geometries and
vibrational frequencies were detd. with each d. functional method. The
method based on the Becke exchange functional and the
Lee-Yang-Parr correlation (BLYP) functional reproduced the exptl.
electron affinities most accurately, having an av. abs. error of 0.15 eV.
Using this functional, the electron affinities were predicted for SiO and
SiO2, mols. for which electron affinities are not known exptl., as 0.11 eV
and 2.03 eV, resp. It is concluded that the accuracy obsd. for d.
functional theory methods applied to first row atoms and mols. extends
to mols. contg. second row atoms and that d. functional theory
continues to provide a computationally affordable means of producing
electron affinities reliable to within a few tenths of an eV of definitive
exptl. values.
383.
130:342364
Treatment of secondary effluent.
Zhang, Yanhui; Li, Xuehua; Shi, Zhihong; Diao, Yu (Changchun Institute
of Environmental Protection, Changchun 130022, Peop. Rep. China).
Huanjing Gongcheng, 17(1), 7-10 (Chinese) 1999 Huanjing Gongcheng
Bianjibu. CODEN: HGONEU. ISSN: 1000-8942. DOCUMENT TYPE:
Journal CA Section: 60 (Waste Treatment and Disposal)
A flotation-filtration-activated C adsorption-ClO2 sterilization process
for treating secondary effluent from biochem. treatment was proposed.
The technol. parameters and equipments were introduced. More than
90% SS and oil and 80% CODCr in the secondary effluent were
removed, and the treated water can be reused.
384.
130:341112
Optimal use of stainless steels in ClO2 bleaching service.
Troselius, L.; Andreasson, P. (Swedish Corrosion Institute, Stockholm,
Swed.). Pulp Pap. Can., 100(2), 17-22 (English) 1999 Southam Inc.
CODEN: PPCAAA. ISSN: 0316-4004. DOCUMENT TYPE: Journal
CA Section: 55 (Ferrous Metals and Alloys) Section
cross-reference(s): 43
The corrosion behavior of different grades of stainless steel has been
investigated in order to find a basis for a tech. and economically
optimal selection of materials for use in D-filter washers and auxiliary
equipment in paper pulp mills. A coupon-testing program has been
carried out in 3 Swedish mills, with contemporaneous measurements of
corrosion and redox potential and the corrosion-affecting parameters:
pH, Cl-, temp., and residual Cl. The major conclusion is that the degree
of corrosion in D-stage filter washers varies amongst different mills and
highly depends upon residual Cl concn. Test coupons of the
superaustenitic material S31254 were resistant to crevice corrosion as
long as the residual Cl did not exceed 50-100 mg/L as active chlorine
at 65癈. Molybdenum-alloyed duplex stainless steels were superior not
only to type 317L but also to the tested superaustenitic steels in terms
of max. depth of crevice corrosion.
385.
130:340497
Chemically induced stimulation of poor deposits in underground coal
formations for increased methane production.
Riese, Walter C.; Bross, Stephen V. (Vastar Resources, Inc., USA).
Ger. Offen. DE 19842407 A1 27 May 1999, 10 pp. (German).
(Germany). CODEN: GWXXBX. CLASS: ICM: E21B043-241. ICS:
E21B043-26. APPLICATION: DE 98-19842407 16 Sep 1998.
PRIORITY: US 97-934722 22 Sep 1997; US 97-934585 22 Sep 1997;
US 97-951719 16 Oct 1997. DOCUMENT TYPE: Patent CA Section:
51 (Fossil Fuels, Derivatives, and Related Products)
Methane prodn. from subterranean coal deposits is chem. induced
using aq. oxidizing solns. of chlorine dioxide, and metal salts of
perchlorates, chlorates, persulfates, perborates, percarbonates,
permanganates, nitrates, and their combinations.
386.
130:340163
Method and device for the production of an aqueous solution containing
chlorine dioxide.
Thangaraj, Appadurai; Speronello, Barry K.; Wildman, Timothy D.
(Engelhard Corporation, USA). PCT Int. Appl. WO 9924356 A1 20
May 1999, 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, GM, HR, 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, UZ, VN, YU, ZW, AM,
AZ, BY, KG, KZ, MD, RU, TJ, TM; RW: AT, BE, BF, BJ, CF, CG, CH,
CI, CM, CY, 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.
APPLICATION: WO 98-US22564 26 Oct 1998. PRIORITY: US
97-965911 7 Nov 1997. DOCUMENT TYPE: Patent CA Section: 49
(Industrial Inorganic Chemicals) Section cross-reference(s): 17
The invention is generally directed to a method of producing an aq.
soln. of ClO2 from the reaction of a metal chlorite and an acid-forming
component which do not react to produce ClO2 in the substantial
absence of water. The reactants are sepd. from liq. water by a
membrane which allows the controlled passage of liq. water and/or
water vapor into contact with the reactants. The generated ClO2
passes out through the membrane into the liq. water to produce the
desired aq. soln. Aq. solns. contg. ClO2 can be conveniently used for
com. and domestic cleaning operations such as in the food industry.
387.
130:339548
Kraft bleach plant ECF conversion: comparison of sequences involving
enzymes, chlorine dioxide, oxygen and hydrogen peroxide.
Sun, Yan Ping (Research and Development Fletcher Challenge Paper,
Tasman mill, Kawerau 3083, N. Z.). Appita J., 52(1), 45-50 (English)
1999 Appita. CODEN: APJOES. ISSN: 1038-6807. DOCUMENT
TYPE: Journal CA Section: 43 (Cellulose, Lignin, Paper, and Other
Wood Products)
Full-time ECF pulp prodn. at a New Zealand bleach plant is in progress
to meet environmental requirements. The main constraint for ECF
conversion is ClO2 capacity. The existing ClO2 generator was
designed for 12 tons/day, limiting the bleach plant prodn. to 400 air-dry
tons/day using a DEoDnD sequence. The lab. results using different
ECF bleaching sequences to maximize the bleach plant prodn. are
summarized. By using enzyme pretreatment (XDEoDnD), the bleach
plant prodn. can be increased to 450 air-dry tons/day. Sequences
DEopDP and DEopPD can increase the bleach plant prodn. rate to
480 air-dry tons/day. Using these sequences with enzymes would allow
the bleach plant prodn. to increase to 520 air-dry tons/day.
388.
130:339544
The generator acid purification (GAP) system reduces caustic make-up
requirements at kraft mills.
Paleologou, M.; Thompson, R.; Berry, R. M.; Brown, C.; Sheedy, M.;
Gilliss, T. (Paprican, Pointe Claire, PQ, Can.). Pulp Pap. Can., 100(2),
34-39 (English) 1999 Southam Inc. CODEN: PPCAAA. ISSN:
0316-4004. DOCUMENT TYPE: Journal CA Section: 43 (Cellulose,
Lignin, Paper, and Other Wood Products)
ClO2 generators for pulp bleaching produce an acidic H2SO4/Na2SO4
byproduct commonly referred to as spent acid. A portion of this stream
is returned to the kraft recovery cycle as Na and S make-up. The
Generator Acid Purifn. (GAP) system employs a fixed-resin bed to
remove H2SO4 from generator spent acid. De-acidified Na2SO4 can
thus be returned to the recovery cycle, thereby avoiding the
consumption of alky. in pulping liquors. In addn., H2SO4 is purified,
providing an opportunity for reuse.
389.
130:329522
Turing pattern formation in the chlorine dioxide-iodine-malonic acid
reaction-diffusion system.
Setayeshgar, Sima (California Institute of Technology, Pasadena, CA,
USA). 117 pp. Avail. UMI, Order No. DA9912877 From: Diss. Abstr.
Int., B 1999, 59(11), 5914 (English) 1998. DOCUMENT TYPE:
Dissertation CA Section: 67 (Catalysis, Reaction Kinetics, and
Inorganic Reaction Mechanisms) Section cross-reference(s): 22, 65
Abstract Unavailable
390.
130:326451
Oxygen pre-bleaching and chlorine dioxide substitution: an emerging
need of Indian paper industry.
Gupta, H. K.; Priti, Shivhare; Roy, T. K.; Mohindru, V. K. (Central Pulp
and Paper Research Institute, Saharanpur 247 001, India). IPPTA,
10(4), 15-24 (English) 1998 Indian Pulp and Paper Technical
Association. CODEN: IPPTDO. ISSN: 0379-5462. DOCUMENT
TYPE: Journal CA Section: 43 (Cellulose, Lignin, Paper, and Other
Wood Products)
The emerging need for introducing O pre-bleaching of pulp and the
possibility of partial substitution of Cl and other Cl-based bleaching
chems. with ClO2 in the Indian pulp and paper industry is discussed. By
adopting O pre-bleaching, the pulp kappa no. can be decreased, and
the low-kappa pulp can further be bleached to the required brightness
(~80% ISO) with the drastic decrease in the amt. of bleaching chems.
and pollution load generation which indirectly results in saving of energy
and other utilities required in effluent treatment. Partial substitution of
Cl and other Cl-based bleaching chems. with ClO2 results in high
brightness, i.e., +88% ISO of the eucalyptus pulp, without adversely
affecting the pulp quality. Substitution of 50-100% Cl with ClO2 in the
chlorination stage, followed by alk. extn. and ClO2 bleaching of the
O-pre-bleached pulps of bagasse, bamboo, and eucalyptus showed
very poor bleaching response. Use of Ca(ClO)2 in or after the extn.
stage showed an improvement in bleaching response. Still there is a
need for extending lab. bleaching studies to optimize the amt. of Cl and
other Cl-based chem. substitution with ClO2, in order to get the max.
bleaching response of the O-pre-bleached pulps of different raw
materials. By introducing the system in Indian mills, the Indian Paper
Industry can expect drastic decrease in the chem. cost, energy cost,
and pollution load generated. To achieve this goal, the mills need to
have very close cooperation with the machine manufacturers to modify
their existing bleaching systems.
391.
130:324539
Chlorine dioxide-containing ice, fresh food preservation using the ice,
and manufacture of chlorine dioxide solution.
Ogawa, Katsutoshi; Ohyama, Masako (Chisso Corp., Japan). Jpn.
Kokai Tokkyo Koho JP 11130407 A2 18 May 1999 Heisei, 4 pp.
(Japanese). (Japan). CODEN: JKXXAF. CLASS: ICM: C01B011-02.
ICS: A01N001-00; A23L003-358; B01F001-00; F25C001-00.
APPLICATION: JP 97-311150 28 Oct 1997. DOCUMENT TYPE:
Patent CA Section: 17 (Food and Feed Chemistry) Section
cross-reference(s): 9
The ice is manufd. by freezing aq. ClO2 solns. of 1-3000 mg/L,
preferably in a gas-permeable container. The ice packed in the
container is used for inhibiting quality deterioration of vegetables, fruits,
seafood, etc., and putrefaction of human remains. Decrease in the
concn. of ClO2 in the ice during transportation or storage is prevented
by freezing the aq. soln. in a gas-impermeable container and placing
the container at a low temp. Release of ClO2 from the ice is
suppressed by packing the ice in a gas-impermeable container and
storing the container in a freezer or a cooler. Aq. ClO2 solns. are
manufd. by slow-thawing or natural melting the Ice. An aq. soln. of ClO2
(0.1 g/L) was frozen in an O-impermeable
polyethylene/nylon/poly(vinylidene chloride) laminate film and the ice
was thawed after 8 days to show the ClO2 concn. 84 mg/L. Application
of the ice to preservation of eggs packed in a corrugated paperboard
box was also shown.
392.
130:316342
Drinking water and waste water disinfection: strategies and problems.
Collivignarelli, Carlo; Conio, Osvaldo; Riganti, Vincenzo; Ziglio,
Giuliano; Bertanza, Giorgio (Department of Civil Engineering,
University of Brescia, Brescia, Italy). Environ. Eng. Renewable Energy,
Proc. Int. Conf., 1st, 285-293. Edited by: Gavasci, Renato; Zandaryaa,
Sarantuyaa. Elsevier Science: Oxford, UK. (English) 1998. CODEN:
67LWA8. DOCUMENT TYPE: Conference CA Section: 61 (Water)
Section cross-reference(s): 60
Within the European Union, many different disinfection systems are
used. They are applied both in facilities for the potabilization of
groundwater and surface water, and for the disinfection of wastewater
after a biol. treatment. Although chem. and phys. processes are usually
used, treatment procedures and results are quite different. In this work,
main disinfection systems used in European Countries in water
potabilization facilities are described. The growing use of surface
water for the prodn. of drinking water, underlines the necessity to
minimize the formation of byproducts with potentially toxic long-term
effect. This leads to define adequate control strategies in potabilization
processes: both used reagents and process schemes must be
analyzed considering this important aspect. In the 2nd part of this
paper, problems dealing with the disinfection of wastewater and the
main characteristics of the most important disinfection systems (as far
as their applicability and efficiency are concerned) are analyzed. The
results of a research carried out in order to compare 4 different
disinfection systems (ozonization, ClO2, UV radiation, and peracetic
acid) are presented.
393.
130:316330
Factors governing odorous aldehyde formation as disinfection
byproducts in drinking water.
Froese, Kenneth L.; Wolanski, Alina; Hrudey, Steve E. (Environmental
Health Sciences, Department of Public Health Sciences, University of
Alberta, Edmonton, AB T6G 2G3, Can.). Water Res., 33(6),
1355-1364 (English) 1999 Elsevier Science Ltd. CODEN: WATRAG.
ISSN: 0043-1354. DOCUMENT TYPE: Journal CA Section: 61
(Water)
Concern over disinfection byproducts (DBPs) in drinking water has
been focused on health risks with little attention to off-flavor
consequences of disinfection. The discovery that odorous aldehydes
could be produced from the chlorination of common amino acids is a
more recent concern. This research documents the yield of 4 odorous
aldehydes produced from 4 common amino acids (isobutyraldehyde
from valine, isovaleraldehyde from leucine, 2-methylbutyraldehyde from
isoleucine, phenylacetaldehyde from phenylalanine) from reactions with
4 common disinfectants, free Cl, monochloramine, ClO2 and O3. Only
free Cl and monochloramine produced substantial yields of the odorous
aldehydes under conditions relevant to drinking water treatment.
Factors affecting the aldehyde yield, including pH, temp., reaction time
and molar ratio (disinfectant/amino acid precursor) were studied. The
highest aldehyde yields were obtained with free Cl, at optimum
conditions of pH 9, molar ratio 1.5, reaction time 2 h and temp. 20*.
Slightly lower yields were obsd. at pH 7. These conditions produced
max. aldehyde yields (% of theor.) for each amino acid precursor as
follows: isobutyraldehyde 66%, 2-methylbutyraldehyde 74%,
isobutyraldehyde 85% and phenylacetaldehyde 87%. Most obsd.
aldehyde concns. at max. yields were in a range of max. values (~50
mg/L) reported in treated drinking water and well in excess of odor
detection thresholds in water.
394.
130:316323
Chlorine dioxide inactivation of Cryptosporidium parvum oocysts in
water.
Liyanage, Lalith Raja Jayanandana (Univ. of Alberta, Edmonton, AB,
Can.). 190 pp. Avail. UMI, Order No. DANQ29064 From: Diss. Abstr.
Int., B 1999, 59(7), 3317 (English) 1998. DOCUMENT TYPE:
Dissertation CA Section: 61 (Water)
Abstract Unavailable
395.
130:313387
Bleaching of chemical pulp with chlorine dioxide and peroxides.
Cho, Takahiro; Koshizuka, Tetsuo; Shimomura, Tadashi (Mitsubishi
Gas Chemical Co., Ltd., Japan). Jpn. Kokai Tokkyo Koho JP
11107180 A2 20 Apr 1999 Heisei, 8 pp. (Japanese). (Japan).
CODEN: JKXXAF. CLASS: ICM: D21C009-02. ICS: B01J023-04;
B01J023-20; B01J023-22; B01J023-24; B01J023-28; B01J023-30;
B01J027-057; B01J027-132; B01J027-14; B01J027-187;
B01J027-188; B01J027-199; D21C009-14; D21C009-16.
APPLICATION: JP 1997-269716 2 Oct 1997. DOCUMENT TYPE:
Patent CA Section: 43 (Cellulose, Lignin, Paper, and Other Wood
Products)
The bleaching is done by delignification of chem. pulp with ClO2 and
peroxide in the presence of group IV, V and VI element oxyacids or
their salts as oxidn. catalysts at an initial pH of 1-3, then
dewatering/washing at a pH of >7 to give pulp with high brightness
without deterioration of fibers. The filtrate contg. catalysts can be
recycled for reuse. Thus, adding dild. H2SO4 to a hardwood kraft pulp
to pH 2, heating with Na2MoO4 0.05, H2O2 0.2 and ClO2 0.2% at a pulp
consistency of 12% at 70* for 2 h, dilg. with water to pulp consistency of
2.5% and pH 11.5, and pressing to pulp consistency of 20% gave a
filtrate with Mo content 97.9% vs. 68.3% if dilg. at pH 6.5 in place of
11.5.
396.
130:313367
How is catalase enzyme activity managed and controlled in the
deinking mill?.
Vernac, Yves; Lenon, Gilles; Escabasse, Jean Yves; Galland, Gerard
(Centre Technique du Papier, Grenoble 38044, Fr.). Prog. Pap.
Recycl., 8(2), 83-88 (English) 1999 Doshi & Associates Inc. CODEN:
PPREFY. ISSN: 1061-1452. DOCUMENT TYPE: Journal CA Section:
43 (Cellulose, Lignin, Paper, and Other Wood Products) Section
cross-reference(s): 7
Investigations on H2O2 bleaching perturbations reported in deinking
mills drew attention to the detrimental effects of catalase (I) activities
related to microorganism growth in water systems. I is produced by
aerobic microorganisms to protect themselves from toxic H2O2
produced during their own metabolic activities. Monitoring studies
were initiated to conduct further investigations on the processes, and to
better understand the extent of the I formation which contributes to a
decrease in bleaching efficiency. Although these studies did not
thoroughly clarify the actual phenomenon involved, early direction was
provided in the development of process treatment programs.
Significant improvements are suggested to control I propensity in
deinking plants, specifically the increase in peroxide dosage, thermal
treatment of the pulp or process waters, and the addn. of specific
chems., e.g. Cl, NaClO, ClO2, and biocides, to deactivate or inhibit I.
397.
130:313356
Reactions of lignin model compounds with chlorine dioxide. Molecular
orbital calculations on dimers.
Elder, T. (School of Forestry, Auburn University, Auburn, AL
36849-5418, USA). J. Pulp Pap. Sci., 25(2), 52-59 (English) 1999
Canadian Pulp and Paper Association, Technical Section. CODEN:
JPUSDN. ISSN: 0826-6220. DOCUMENT TYPE: Journal CA Section:
43 (Cellulose, Lignin, Paper, and Other Wood Products)
Given that elemental Cl has been largely supplanted by ClO2 as a
bleaching agent for pulp, there is increasing interest in the chem. of the
latter, and the mechanisms responsible for its delignification reactions.
This was investigated exptl., and based on the proposed mechanisms,
semi-empirical MO calcns. were performed on etherified and phenolic
model compds. representative of the condensed structures that occur
in residual lignin. From these calcns., the initial oxidn. reaction of each
model compd. was shown to be exothermic, whereas the measures of
reactivity, e.g. charge, MO d., and bond order, indicated that the
phenolic structure is more susceptible to reaction than the etherified
model.
398.
130:313340
Chlorine dioxide substitution reaction pathways: A model lignin
evaluation.
Hart, Peter W.; Hsieh, Jeffery S. (Pulp and Paper Engineering
Program, Georgia Institute of Technology, Atlanta, GA 30332, USA).
AIChE Symp. Ser., 319(Innovative Advances in the Forest Products
Industries), 73-81 (English) 1998 American Institute of Chemical
Engineers. CODEN: ACSSCQ. ISSN: 0065-8812. DOCUMENT
TYPE: Journal CA Section: 43 (Cellulose, Lignin, Paper, and Other
Wood Products)
Phenol and 3-ethoxy-l-propanol were used as representatives of kraft
lignin to aid in the elucidation of the reaction pathway assocd. with
chlorine dioxide substitution during kraft pulp bleaching.
Pseudo-reaction rate consts. and the order of reaction were detd. for
reactions of each of the model compds. with chlorine, chlorine dioxide,
and mixts. of chlorine and chlorine dioxide. The effects of the order of
chem. addn. were also detd. No attempt was made to postulate actual
reaction pathways. Rather, global reaction kinetics as detd. by a
simple power law rate model were evaluated in an attempt to
understand bleaching results seen in industry. Model compds. were
employed instead of actual kraft lignin to reduce the no. of possible
reactions thus allowing for easier interpretation of the results. The
model lignin bleaching results indicate chlorine reacts with the arom.
portion of the kraft lignin about three times faster than chlorine dioxide.
Chlorine was also found to react with a wider range of chems. than
chlorine dioxide. Order of addn. studies indicate chlorine dioxide
should be added before chlorine in order to obtain the largest no. of
lignin reactions. The global reaction rate consts. for mixts. of chlorine
and chlorine dioxide were equiv. to the sum of the rate consts. for
chlorine alone and chlorine dioxide alone, indicating chlorine and
chlorine dioxide do not interfere with each other during lignin reactions.
Model compd. results strongly support the theory that chlorine dioxide
substitution is a competing parallel reaction pathway with little or no
interaction between the chlorine and chlorine dioxide. The majority of
the rapid lignin reactions occur between the bleaching chems. and the
arom. portions of the kraft lignin. When chlorine and chlorine dioxide
are present in a specific bleaching stage, true competitive reactions
occur. Thus, more reactions between the bleaching chems. and lignin
occur when the less aggressive chem., chlorine dioxide is added
before the more reactive chlorine.
399.
130:310865
Study on drying characteristics and sterilization mechanism of
adsorption drying system.
Liu, Zhiwei; Yu, Ruoqian; Ding, Jing; Liang, Shizhong; Shao, Shan
(Department of Bioengineering, South China University of Technology,
Canton 510641, Peop. Rep. China). Shipin Gongye Keji, (6), 4-7
(Chinese) 1998 Shipin Gongye Keji Bianjibu. CODEN: SGOKE6.
ISSN: 1002-0306. DOCUMENT TYPE: Journal CA Section: 17 (Food
and Feed Chemistry)
The drying characteristics and sterilization mechanism of adsorption
drying system using carrot as raw material were studied. The factors
affecting the adsorption drying system (humidity, temp., and velocity of
drying air, and surface area of raw material) were discussed. The
results showed that original nutrient, color, perfume and taste of carrot
were basically kept after drying. Rotary dehumidifier and high efficient
filter kept the system clean, and the addn. of sterilizing agent ClO2 was
beneficial to sterilization of air and products.
400.
130:303912
Simulation of radiation-chemical behavior of americium in perchloric
acid. II. 6-12 M HClO4.
Vladimirova, M. V. (State Scientific Center, Bochvar All-Russia Institute
of Inorganic Materials, Moscow, Russia). Radiochemistry (Moscow),
41(1), 59-67 (English) 1999 MAIK Nauka/Interperiodica Publishing.
CODEN: RDIOEO. ISSN: 1066-3622. DOCUMENT TYPE: Journal
CA Section: 74 (Radiation Chemistry, Photochemistry, and
Photographic and Other Reprographic Processes)
The radiation-chem. behavior of Am(VI), Am(V), and Am(III) in 6-12 M
HClO4 was simulated. The previously unknown rate consts. of certain
reactions were obtained by comparison of the calcd. and exptl. data.
The mechanisms and kinetic features of americium redox transitions in
concd. HClO4 solns. were detd.