Interactions Between Ozone,Halogens and Organic Compounds

During drinking-water treatment, ozone used as a preoxidant and chlorine required for final disinfection, lead to competing chemical reactions, in the case of raw water containing both organic compounds and inorganic salts (such as bromides and ammonia).

The study of the interactions between those reactants has been made according to the following main topics :

As for THM formation, experiments conducted on simple organic compounds or on natural fulvic acids show important decreases in THM or TCAA formation after ozonation. It may be noticed, however, that the ozonation of surface waters may induce the formation of haloform precursors, usually with a low level of reactivity.

In water supplies containing bromide ions, oxidation of the latter through hypobromous acid may take place during the ozonation stage. Failing preozonation treatment, hypobromous acid is generated very rapidly during chlorination, thus inducing the formation of chloro- brominated organic compounds.

During the ozonation of fulvic acid solutions, the presence of small amounts of bicarbonate was found to improve precursor removal significantly.

It can be concluded that the partial analogy of the action of ozone or chlorine on aromatic structures, whether simple or complex (such as humic and fulvic acids), seems to indicate that the consequence of preozonation is the destruction, at least in part, of the most reactive sites for THM production, thus leading to a decrease of the volatile organochlorinated compounds formed during the post-chlorination. However, some ozonation products of natural waters are THM precursors, though of low reactivity. Then, in the presence of bromide ions, the formation of volatile organobrominated compounds may be observed during ozonation.     

Ozonation of Humic Substances: Effects on Molecular Weight Distributions of Organic Carbon and Trihalomethane Formation Potential

Four different sources of humic substances were studied to determine the effects of ozonation on molecular weight-distributions, based on dissolved organic carbon (DOC) and trihalomethane formation potential (THMFP). Solutions of two soil-derived fulvic acids and a one soil-derived humic acid, as well as dissolved organic matter (DOM) associated with a natural water source were studied. Both gel permeation chromatography (GPC) and ultrafiltration (UF) were employed to define apparent molecular weight (AMW). Applied ozone doses ranged from 2.0 to 2.5 mg O₃/mg DOC. Overall samples of untreated and ozonated waters, as well as individual molecular weight fractions, were characterized according to DOC, UV absorbance, and THMFP. Ozonation resulted in a significant disappearance of higher AMW material with a corresponding increase in lower AMW material. Although little overall reduction in DOC concentration was observed, significant overall reductions in UV absorbance and THMFP levels were observed.     

克拉玛依原油中活性组分的分离与分析

用碱醇液萃取法从克拉玛依原油中分离出了界面活性组分并进行了元素分析,通过硅胶柱层析按极性大小将该活性组分分成了５个级分,对５个级分进行了红外光谱分析,发现其主要成分是石油酸。用旋转滴法测定了该活性组分及其５个级分与碱水间的界面张力,结果表明的含氮化合物及石油酸具有较高的界面活性,可以使原油与ＮａＯＨ水溶液的界面张力降至１０＾－２ｍＮ／ｍ。     

原油碱水乳化活性组分研究

对河南油田三种原油中的有机酸和非酸含氧化合物进行了分离鉴定并研究了它们在碱水乳化中的作用。有机酸是引起各原油碱水乳化的活性物质，非酸含氧化合物本身无碱水乳化活性，但对有机酸的乳化活性有协同作用。     

胞外表面活性物质在石油烃生物降解过程中的形成及其作用

采用SBR法处理含葡萄糖和石油烃的人工废水,实验结果表明：在生物处理过程中,微生物首先快速吸附、降解葡萄糖,石油烃类随后也能得到有效降解;在烃类与葡萄糖共存的情况下,微生物在胞外产生更多的蛋白类物质：含石油烃和不合石油烃反应器中污泥胞外蛋白类物质平均含量分别为82．9和58．1mg／gVSS,EPS的乳化指数分别为50％和12．5％,说明胞外的蛋白类物质具有一定的表面活性,可以将烃类在一定程度上乳化,从而有利于微生物对烃类的接触和摄取。     

Multivariate analysis of anionic, cationic and nonionic textile surfactant degradation with the H(2)O(2)/UV-C process by using the capabilities of response surface methodology

Anionic, cationic and nonionic surfactants being frequently employed in the textile preparation process were subjected to H(2)O(2)/UV-C treatment. As a consequence of the considerable number of parameters affecting the H(2)O(2)/UV-C process, an experimental design methodology was used to mathematically describe and optimize the single and combined influences of the critical process variables treatment time, initial H(2)O(2)concentration and chemical oxygen demand (COD) on parent pollutant (surfactant) as well as organic carbon (COD and total organic carbon (TOC)) removal efficiencies. Multivariate analysis was based on two different photochemical treatment targets; (i) full oxidation/complete treatment of the surfactants or, alternatively, (ii) partial oxidation/pretreatment of the surfactants to comply with the legislative discharge requirements. According to the established polynomial regression models, the process independent variables "treatment time" (exerting a positive effect) and "initial COD content" (exerting a negative effect) played more significant roles in surfactant photodegradation than the process variable "initial H(2)O(2) concentration" under the studied experimental conditions.     

有机添加剂对模拟油EACN值及动态界面张力的影响

本文通过改变两种石油磺酸盐的混合比例,配制出碳数最低值不同的一系列混合表面活性剂溶液作为标尺,考察了几种有机酸、十八醇、Ｓｐａｎ６０ 及两种卟啉（ ＯＥＰ和ＥＴＩＯ） 对正癸烷模拟油的ＥＡＣＮ 值及油水界面张力的影响。     

Effects Of Catalysts During Ozonation Of Salicylic Acid,Peptides And Humic Substances In Aqueous Solution

The oxidation of two model molecules (salicylic acid and a peptide) and humic substances in aqueous solution was studied using ozone in the presence of various catalysts. Experiments were performed in reactors operated either in batch (TOC_o = 2.5 mg C.L^?1) or in semi-continuous flow mode (TOC_o = 42 mg C.L^?1).     

Bromoform Formation in Ozonated Groundwater Containing Bromide and Humic Substances

The effect of bromide ion, organic carbon concentration (natural aquatic humic substances), pH, and solar irradiation on the formation of bromoform in ozonated groundwater has been studied. The studies were conducted on four unique samples of groundwater taken from different regions of the Biscayne Aquifer in southern Florida. All other conditions being equal, increases in bromide ion concentrations resulted in increases in CHBrg formation. In three of the four samples, CHBr₃ formation decreased as the pH level increased from 5 to 9. The fourth sample exhibited an opposite trend whereby the CHBr₃ concentration increased with increasing pH. Bromoform concentration increased with increased O₃ concentration over an ozone dosage range of 3.4 to 6.7 mg/L.     

Supercritical fluid extraction and bioassay identification of prodrug substances from natural resources

For arbitrarily chosen thirty types of natural resources which have been widely used in oriental traditional herb medicine, supercritical CO₂ extraction (SFE) and organic liquid solvent extraction (LSE) withn-hexane, chloroform and methanol were carried out to extract pharmaceutical substances. To evaluate relative advantages and shortcomings between the SFE and LSE, five types of bioactivity assays as well as gas- and thin layer-chromatographic analysis were performed for all the extracts obtained by the two extraction methods. Types of bioassays performed included cytotoxicity, bleb forming, DNA binding, oxygen free radical scavenger and Xanthine oxidase inhibitor tests. To evaluate economic viability of the SFE over the traditional LSE, extractability of prodrug substances was evaluated as the functions of extraction temperature and pressure. SFE was proven to be a feasible alternative over LSE. Also, the optimum SFE conditions which provided maximum extraction and cytotoxicity for each selected sample were presented.