半连续活性污泥法测定表面活性剂的好氧生物降解度

用半连续活性污泥(SCAS)法测定表面活性剂的生物降解度,考察了表面活性剂分子在活性污泥体系中的吸附-脱附作用所导致的假降解现象,研究了活性污泥浓度对降解性能的影响,并用SCAS法对AEO7、L-64、LAS和AES进行了初级和最终生物降解度的测定,结果表明以上4种表面活性剂的初级生物降解度均>90%、最终生物降解度均>70%,达到了欧盟洗涤剂法规的相关标准,均属易降解表面活性剂。     

表面活性剂生物降解性能的研究进展

对表面活性剂的生物降解性能进行了全面概述。着重讨论了表面活性剂的降解性能测试方法、生物降解机理、降解动力学及用于量化分析可生物降解的同位素标记反应运移模型,并对各类表面活性剂结构与降解能力作了评价。最后,指出了我国表面活性剂生物降解度研究的发展方向。     

表面活性剂的结构与生物降解性的关系

对表面活性剂的生物降解性进行了全面的概述，着重讨论了表面活性剂的降解性能与结构的关系。表面活性剂的生物降解性主要由疏水基团决定，并随着疏水基线性程度的增加而增加，末端季碳原子会显著降低降解度，疏水链长短也影响降解性；表面活性剂的亲水基性质对生物降解度有次要的影响；乙氧基链长影响非离子表面活性剂的生物降解性；增加磺酸基和疏水基末端之间的距离，烷基苯磺酸盐的初级生物降解度增加（距离原则）。最后指出了我国今后表面活性剂生物降解度研究的发展方向。     

表面活性剂生物降解度的测定

建立和完善了表面活性剂生物降解度的测定方法，包括活性污泥的制备、培养、驯化和降解等试验过程。并以此方法对常见的阴离子和非离子表面活性剂的生物降解性进行测定，结果表明AES和异构C13醇AEO7需1d完全降解；天然醇AOS、AEO7和TX－10需2d完全降解；SAS和聚醚需3d完全降解；LAS则需4d完全降解，与文献完全吻合，验证了该方法的可靠性。该方法具有较好的重要性。     

表面活性剂生物降解性的研究进展

简述了表面活性剂对生态环境的影响及其对生物体存在的毒害性作用;概括了常用的表面活性剂模拟降解的方法及其检测手段;总结了表面活性剂生物降解的一般规律及新型绿色表面活性剂的生物降解性;介绍了表面活性剂降解性能的影响因素,并对今后表面活性剂生物降解性研究的发展方向进行了展望。     

表面活性剂降解研究进展

简述了表面活性剂对环境的影响及其降解的发展概况，着重讨论了表面活性剂的各种生物降解的研究方法和特点，降解动力学，结构与降解性能间的关系，影响降解的环境因素及直链烷基苯磺酸盐（LAS），烷基硫酸盐（AS）等几类常见表面活性剂的生物降解机理。并对近年发展起来的表面活性剂光催化降解的研究方法，降解机理及降解动力学作了简要介绍。     

表面活性剂生物降解的标准与法规

表面活性剂对环境的影响引起了各国和地区的关注，纷纷建立标准与法规，引导表面活性剂向着正确的方向发展。表面活性剂对环境的影响主要表现为其生物降解性。简要概述了各组织建立的表面活性剂生物降解测试方法、降解性能要求及各国为表面活性剂建立的一些法规。阐述了我国表面活性剂生物降解标准的现状及发展趋势。     

聚氧乙烯醚类表面活性剂生物降解度测定方法的改进

对聚氧乙烯醚类非离子表面活性剂生物降解度的测定方法———硫氰酸钴法进行了改进:三氯甲烷取代苯作为萃取剂;萃取次数从1次增加到3次;硫氰酸钴与表面活性剂的络合反应时间为15 min。实验结果表明:重复性实验的相对标准偏差<6.0%;对AEO7、Tween85和AEO30的平均回收率在97%~104%,相对标准偏差<4.0%。对原方法不宜测定的一些类型的聚氧乙烯醚类非离子表面活性剂的生物降解度进行测定,结果表明:对单EO链、单烷基链非离子表面活性剂,EO数从3~12可扩大到3~30,并能测定多个EO链、多个烷基链聚氧乙烯醚类非离子表面活性剂的生物降解度。     

表面活性剂最终生物降解试验装置的搭建及可行性研究

搭建了与OECD 301B相适应的表面活性剂最终生物降解装置,通过对样品醋酸钠及阴离子表面活性剂LAS生物降解性测定,表明该装置研究表面活性剂最终生物降解性能的可行性。应用该装置测定APG0810,其最终生物降解率为86.5%。     

表面活性剂的绿色化及研究进展

简述了表面活性剂对环境的影响及研究进展。着重讨论了表面活性剂的研究方法及表征,各种生物降解过程、降解机理和影响表面活性剂生物降解的因素。并对表面活性剂的安全性及毒性、温和性及对皮肤和黏膜的刺激性进行了简要介绍。     

Biodegradability and aquatic toxicity of glycoside surfactants and a nonionic alcohol ethoxylate

The environmental properties of three glycoside surfactants and one alcohol ethoxylate were examined by standardized laboratory methods. All of the surfactants biodegraded extensively in aerobic screening tests and may be assumed to approach 100% removal in aerobic wastewater treatment plants, except in cases of high loadings or otherwise exceptional conditions. Anaerobic biodegradability tests showed that an ethyl glycoside monoester (EGE) and a linear alkyl polyglycoside (APG) were both mineralized (>70%) under methanogenic conditions. In contrast, a branched APG resisted anaerobic degradation, while the alcohol ethoxylate was partially mineralized by anaerobic bacteria. The EGE surfactant was most rapidly mineralized in aerobic and anaerobic biodegradability tests. None of the surfactants inhibited respiration in activated sludge at the highest concentration tested (200 mg/L). Tests with aquatic organisms showed increasing toxicity in the following order: branched APG<EGE<linear APG<alcohol ethoxylate. Negligible aquatic toxicity was observed for the branched APG, while the alcohol ethoxylate was highly toxic to examined organisms. This evaluation demonstrates that considerable variation in biodegradability and toxicity responses can be seen within structurally related glucose-based surfactants.     

季铵盐类表面活性剂的生物降解性与其结构的关系

引　言季铵盐是一类阳离子表面活性剂 ,2 0世纪以来已越来越多地应用于工业和日用品中 .随着表面活性剂工业的发展 ,该系列化合物不断开发出新用途 ,在许多行业和领域发挥了重要作用 ,例如在轻工、纺织助剂、石油化学品、卫生用品添加剂等领域用作抗静电剂、柔软剂、腐蚀抑制剂     

烷基苯磺酸盐的生物降解性与其结构及降解时间的关系研究

运用拓扑指数研究方法，证明阴离子表面活性剂烷基苯磺酸盐系列化合物的生物降解性与其结构及降解时间之间具有明显的相关性，通过回归分析得到降解性（Y）与分子二阶连接性指数（2Xn)及降解时间（T）的相关模型方程式，其复相关系数R＞0．09，标准偏差E＝1．131，平均标准偏差D＝0．017，在传统的单变量QSBR－表面活性剂生物降解与其结构之间的定量关系研究中引入第二变量时间因子，是一种新的尝试，补充和完善了QSBR，提高了结果的合理性和准确性，也扩大了其适用范围，为众多的同名系列化合物生物降解性的预测和评价提供了一种新的方式和手段。     

Primary aerobic biodegradation of cationic and amphoteric surfactants

The primary aerobic biodegradation of several cationic and amphoteric surfactants has been studied by using the shaking-flask degradation test and orange II spectrophotometric analysis. The results show that cationic and amphoteric surfactants can be readily biodegraded, with their degradation exceeding 94%. The degradation kinetics can be accurately described by the Boltzmann model. The relationship between structure and biodegradability is discussed. The presence of hydrophobic groups has a strong effect on the biodegradability of these surfactants. Biodegradability decreases with increasing chain length. The presence of hydrophilic groups mainly affects the degradation rate of these surfactants, but not their ultimate biodegradeability. Bio-degradability is deterred and degradation is slowed as steric hindrance increases. Degradation rates increase markedly when hydrophilic groups containing an amide bond are pres-ent.     

Biodegradability of nonionic surfactants: Screening test for predicting rate and ultimate biodegradation

Environmental water quality evaluations of raw materials in consumer products occupy a position of critical importance in many industries throughout the world. The rapid growth and diversity of the household detergent market requires continuous consideration of new materials needed to meet the demands of new, improved and modified products. As household cleaning products are normally disposed of as a component of domestic sewage, surface active compounds, including nonionic surfactants, would reach surface waters only as a part of a sewage effluent and would be subject to the same degree of biological treatment as the balance of the waste. For this reason, evaluations of such new materials include an environmental assessment in which biodegradability testing of organic materials is an important first step. Biodegradability characteristics of nonionic surfactants, as a class, are generally more difficult to ascertain because of wide structural diversity and a usual lack of functional groups. Such determinations usually involve intricate and laborious test methods which necessitate development of analytical techniques for each degradation product of a given material. A method has been developed, modified and used in our laboratory, that provides, after reasonable opportunity for biological acclimation, a measure of the rate and degree of ultimate biodegradation (conversion to CO₂ and H₂O). This method, which uses simple equipment, has been used to assess the biodegradability of a wide variety of nonionic surfactants, without necessitating the development of specific analytical methods for each surfactant under consideration. Additionally, this method can be adapted to measure degradation under conditions of anaerobiosis or low temperature.     

Research on Primary Biodegradation of Alkyl Ethoxy Glucoside

This investigation was performed to determine the anaerobic biodegradation of alkyl ethoxy glucoside (AEG) nonionic surfactants using the OECD 311 method. The influence of different initial concentrations of AEG on the primary biodegradation rate was investigated using the anthrone analysis method. The results show that different initial concentrations have similar good biodegradability and the biodegradation rate can reach more than 90 % even at the highest initial concentration of 100 mg/l. Alkyl polyglucoside (APG) surfactants have previously been confirmed as readily biodegradable. The profile of concentration changes over the incubation time of AEG and APG had similar trends. Therefore, AEG are also considered as readily biodegradable. The gas chromatograph‐mass spectrometer analytical method was used to identify the metabolites. The content of alcohol ethoxylate (AEO) increased with decrease in the number of AEG at the initial stage of degradation. It was found that AEO with longer EO chains disappeared first. Accordingly, a degradation pathway that accounts for the experiment results was proposed.     

Biodegradable polymers: IV. Spectral,thermal, and mechanical properties of cross‐linked soy protein concentrate

Soy protein concentrate, a potential alternative to petrochemical polymers, was cross‐linked with formaldehyde at 0.5, 1, 2.5, 5 and 7.5 % (w/w). The materials were then compression‐moulded into plastic tensile bars and tested for tensile and yield strength, percentage elongation and water absorption. The infrared spectra of the cross‐linked product were studied. The degradation pattern of the cross‐linked product was monitored by thermogravimetric analysis. A computerised LOTUS package method that we developed was used for evaluating the kinetic parameters. The biodegradability of the cross‐linked product was also investigated. Copyright © 2005 Society of Chemical Industry