摘要:

An improved procedure was used to isolate and fractionate natural organic matter (NOM) in water for subsequent ozonation and disinfection by-product (DBP) and color removal quantisation. Isolated NOM fractions from two different sources, accounting for approximately 50 to 60% of the dissolved organic material and 60 to 75% of the color, were characterized and then ozonated under conditions approximating those encontered during drinking water treatment. The natural waters also were ozonated. Organic DBPs of either health concern or which may contribute to biological instability of finished water were investigated, including aldehydes, oxoacids and low molecular weight carboxylic acids. pH and ozone dosage were the parameters having the greatest effect on DBP formation. On the basis of UV absorbance measurements, the fulvic acid fractions studied taken together accurately represented the natural water and may be the primary sources of precursor material for aldehydes and oxoacid DBPs. However, as yet unidentified NOM fractions contribute significantly to carboxylic acid formation upon ozonation.

ISSN:0191-9512    

DOI:10.1080/01919519408552376

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Preozonation was investigated for its effects on the biodegradability of five chlorophenolic compounds in activated-sludge systems. The biodegradability was expressed in terms of the oxidation of each compound itself and of the total organic contents of the whole sample.

ISSN:0191-9512    

DOI:10.1080/01919519408552377

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The quality of water provided by the Budapest Waterworks should comply with the standards prescribed by the European Community. According to these provisions, on one of the major water-producing regions (Csepel Island), rows of wells of 60,000 m3/day yield have been closed recently, and in the immediate future further plants would have been closed because of the high iron and manganese content of the water.

ISSN:0191-9512    

DOI:10.1080/01919519408552378

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The aim of this work was to study the reaction of ozone and combined ozone/hydrogen peroxide on oxygenated additives such as methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE) in dilute aqueous solution using controlled experimental conditions. Experiments conducted in a semi-continuous reactor with MTBE and ETBE in combination (initial concentration: 2 mmol/L of each) showed that ETBE was better eliminated than MTBE with both ozone and combined O3/H2O2. Batch experiments led to the determination of the ratio of the kinetic constants for the reaction of OH°-radical with MTBE and ETBE [kOH°/ETBE/kOH°/MTBE= 1.7). Tert-butyl formate and tert-butyl acetate were identified as the ozonation byproducts of MTBE and ETBE, respectively, while tert-butyl alcohol was found to be produced during the ozonation of both compounds.

ISSN:0191-9512    

DOI:10.1080/01919519408552379

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

There are numerous reports on coagulation/flocculation effects of preozonation, which cannot be interpreted by one single mechanism. About 7 basic processes are presently discussed. This paper presents results from drinking and wastewater treatment, indicating that preozonation effects can be explained with algae flocculation, with the destabilization of particles, and with polymerization of the dissolved organics. In view of the complexity of the systems, it is anticipated that several processes can be responsible, leading to an optimum ozone dosage.

ISSN:0191-9512    

DOI:10.1080/01919519408552380

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The disinfection effects of the ozone molecule alone and that of ozone decomposition products when inactivatingGiardia muriscysts were investigated at bench-scale using two different ozone demand-free laboratory buffer systems. The first water was a 0.05 M phosphate buffer with hydrogen peroxide added at a 10:1 weight ratio. The second water was a 0.05 M phosphate – 0.01 M bicarbonate buffer which quickly scavenged radical species from ozone decomposition. The C3H/HeN mouse model was used to assess the infectivity of ozone treated cysts.

ISSN:0191-9512    

DOI:10.1080/01919519408552381

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A flow injection, non-ion chromatographic method has been developed using chlorpromazine for the determination of bromate ion in ozone treated waters containing bromide ion. The procedure has been automated over a linear operating range of 1.0 to 30.0 μ/LThe precision of the method in reagent water is calculated to be better than 2.5% with an accuracy within ± 1 μ/LThe method detection limit (MDL) is 0.8 μ/L. Chemical masks are described to minimize potential interference from nitrite ion and chlorite ion.

ISSN:0191-9512    

DOI:10.1080/01919519408552382

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:0191-9512    

DOI:10.1080/01919519408552375

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor