水和废水中阴离子表面活性剂测定干扰因素试验研究

对二氮杂菲萃取分光光度法测定水和废水中阴离子表面活性剂的主要干扰因素进行了试验研究.设计了温度过低、浑浊带色和混溶乳化3种干扰试验方案,探讨了各干扰因素在不同工况下的试验结果、影响程度及消除措施.提出温度过低须在测定前提高环境温度,以确保显色反应完全;浑浊带色须在测定中采用色(浊)度校正法消除干扰;混溶乳化可在测定中利...     

Adsorption-desorption behavior of acetochlor to soils in the presence of some environmental substances

ＩｎｔｒｏｄｕｃｔｉｏｎＡｌｔｈｏｕｇｈｔｈｅｈｅｒｂｉｃｉｄｅａｃｅｔｏｃｈｌｏｒ [2 ｃｈｌｏｒｏ Ｎ (ｅｔｈｏｘｙｍｅｔｈｙｌ) Ｎ (2 ｅｔｈｙｌ 6 ｍｅｔｈｙｌｐｈｅｎｙｌ)ａｃｅｔａｍｉｄｅ]ｈａｓｂｅｅｎｕｓｅｄｆｏｒｔｅｎｙｅａｒｓｉｎＣｈｉｎａ,ｌｉｍｉｔｅｄｉｎｆｏｒｍａｔｉｏｎｈａｓｂｅｅｎｃｏｌｌｅｃｔｅｄｔｏｄｅｔｅｒｍｉｎｅｉｔｓｆａｔｅａｎｄｔｒａｎｓｐｏｒｔｉｎｔｈｅｅｎｖｉｒｏｎｍｅｎｔ.Ｆｏｒｍｕｌａｔｉｏｎｓａｒｅｇｅｎｅｒａｌｌｙｓｏｌｄａｓｅｍｕｌｓｉｆｉａｂｌ…     

活化剂联合植物移除污染土壤重金属的研究进展

土壤重金属活化移除技术作为一种快速有效的污染土壤治理技术,越来越受到重视。综述了近年来螯合剂、低分子有机酸、表面活性剂等不同活化剂对重金属的活化移除效果,包括活化剂对部分重金属形态变化的影响以及与植物联合修复的效果,并综合考虑其本身的生物降解性和生态毒性等优缺点,以期为研究重金属污染土壤修复技术提供参考。     

Alcohol ethoxylate mixtures in marine sediment: Competition for adsorption sites affects the sorption behaviour of individual homologues

Mineral surfaces form the main sorption phase for alcohol ethoxylates (AEs) in marine sediment. Competition for adsorption sites is investigated for marine sediment and kaolinite clay using simple mixtures of AE homologues. For both sorbents, adsorption sites on mineral surfaces can be effectively blocked by an AE homologue with the strongest adsorption affinity. The strongly adsorbed AE, however, forms a second sorption phase to which weakly adsorbing AE will sorb, forming bilayers. An extended dual-mode model accounts for competition effects, while still based on sorption properties of individual compounds. Competition effects become apparent when total adsorbed concentrations reach ∼10% of the adsorption capacity. Deviations from individual sorption isotherms depend on affinity constants and dissolved homologue composition. Competition will not often occur in contaminated field sediments, with AEs concentrations usually far below the adsorption capacity, but will affect sorption studies, sediment toxicity tests or applications with nonionic surfactant mixtures.     

非一阴离子表面活性剂对PAHs的增溶作用及无机盐的强化效果研究

文章研究了几种非离子和阴离子表面活性剂在单一或混合条件下对多环芳烃（PAHs）萘和菲的增溶作用,并分析了无机盐对表面活性剂增溶PAHs的强化效果.结果表明,在相同浓度条件下,非离子表面活性剂对菲和萘的增溶效果均高于阴离子表面活性剂,其增溶能力大小顺序为：Tween 80 ＞TX-100＞ Tween 20＞ SDS＞SDBS.将非离子与阴离子表面活性剂混合后,对萘和菲的增溶作用大于单一阴离子表面活性剂而小于单一非离子表面活性剂,且增溶效果随着非离子表面活性剂比例的增加而增大.低浓度（0.03 mol/L）的NaCl和Na2SO4可大幅度促进表面活性剂对萘和菲的增溶效果,但随着无机盐浓度的提高,对增溶效果的促进作用不明显.     

Enhancing plant-microbe associated bioremediation of phenanthrene and pyrene contaminated soil by SDBS-Tween 80 mixed surfactants

The use of surfactants to enhance plant-microbe associated dissipation in soils contaminated with polycyclic aromatic hydrocarbons(PAHs) is a promising bioremediation technology. This comparative study was conducted on the effects of plant-microbe treatment on the removal of phenanthrene and pyrene from contaminated soil, in the presence of low concentration single anionic, nonionic and anionic-nonionic mixed surfactants. Sodium dodecyl benzene sulfonate(SDBS) and Tween 80 were chosen as representative anionic and nonionic surfactants, respectively. We found that mixed surfactants with concentrations less than 150 mg/kg were more effective in promoting plant-microbe associated bioremediation than the same amount of single surfactants. Only about(m/m) of mixed surfactants was needed to remove the same amount of phenanthrene and pyrene from either the planted or unplanted soils, when compared to Tween 80. Mixed surfactants( 150 mg/kg) better enhanced the degradation efficiency of phenanthrene and pyrene via microbe or plant-microbe routes in the soils. In the concentration range of 60–150 mg/kg, both ryegrass roots and shoots could accumulate 2–3 times the phenanthrene and pyrene with mixed surfactants than with Tween 80. These results may be explained by the lower sorption loss and reduced interfacial tension of mixed surfactants relative to Tween 80, which enhanced the bioavailability of PAHs in soil and the microbial degradation efficiency. The higher remediation efficiency of low dosage SDBS-Tween 80 mixed surfactants thus advanced the technology of surfactant-enhanced plant-microbe associated bioremediation.     

Influence of residual surfactants on DNAPL characterization using partitioning tracers

The partitioning tracer technique is among the DNAPL source-zone characterization methods being evaluated, while surfactant in-situ flushing is receiving attention as an innovative technology for enhanced source-zone cleanup. Here, we examine in batch and column experiments the magnitude of artifacts introduced in estimating DNAPL content when residual surfactants are present. The batch equilibrium tests, using residual surfactants ranging from 0.05 to 0.5 wt.%, showed that as the surfactant concentrations increased, the tracer partition coefficients decreased linearly for sodium hexadecyl diphenyl oxide disulfonate (DowFax 8390), increased linearly for polyoxyethylene (10) oleyl ether (Brij 97), and decreased slightly or exhibited no observable trend for sodium dihexyl sulfosuccinate (AMA 80). Results from column tests using clean sand with residual DowFax 8390 and Tetrachloroethylene (PCE) were consistent with those of batch tests. In the presence of DowFax 8390 (less than 0.5 wt.%), the PCE saturations were underestimated by up to 20%. Adsorbed surfactants on a loamy sand with positively charged oxides showed false indications of PCE saturation based on partitioning tracers in the absence of PCE. Using no surfactant (background soil) gave a false PCE saturation of 0.0004, while soil contacted by AMA 80, Brij 97, and DowFax 8390 gave false PCE saturations of 0.0024, 0.043, and 0.23, respectively.     

CTMAB／SDS改性沸石对水中痕量邻苯二甲酸酯吸附机制

以季铵盐阳离子表面活性剂CTMAB及阴离子表面活性剂SDS对粉末状天然沸石进行复合改性,制备得到了CTMAB／SDS改性沸石。对改性沸石及天然沸石进行红外吸收光谱及XRD衍射表征,并研究了PAEs在天然沸石和CT-MAB／SDS改性沸石上的吸附机制。结果表明,阴阳离子表面活性剂没有对层状结构的键型造成较大的影响;PAEs在天然沸石和CTMAB／SDS改性沸石上的吸附更符合表面吸附一分配作用复合模型;PAEs的表面吸附和分配作用对吸附作用的贡献主要受吸附剂中有机质含量及吸附物质大小、极性及溶解度的影响。     

Photocatalytic degradation of bentazone in soil washing wastes containing alkylpolyoxyethylene surfactants

Three alkylpolyoxyethylene surfactants bearing the same hydrophobic chain and a different number of oxyethylene groups were investigated as suitable candidates for the soil washing treatment of contaminated soil samples containing bentazone. Comparable good recoveries of the pesticide were obtained working with these surfactants. The photocatalytic treatment of the collected washing wastes, performed in the presence of suspended TiO₂ particles under irradiation with simulated sunlight, leads to the effective degradation of bentazone residues after a time depending on the nature and concentration of the chosen amphiphile. Brij 35 was found to be the best surfactant candidate, giving the faster abatement of the pesticide in the collected wastes. The overall treatment time depends on the bentazone mineralization kinetics, markedly slow in the presence of surfactants. Useful information about the photocatalytic degradation route was obtained from the HPLC-MS analysis of transient intermediates formed in water.