Effects of Linear Alkylbenzene Sulphonates (LASs) on Exogenous Organic Matter Content and Evolution in Sewage Sludge–Amended Soils

Abstract

Linear alkylbenzene sulphonates (LASs) are anionic surfactants commonly used in commercial detergents. A potential risk associated with the recycling of sewage waste materials is the presence of LASs and their primary degradation products, which could accumulate in sludge, especially during anaerobic processing. The long‐term accumulation of these contaminants in soils and especially the potential disturbance of soil functions need to be studied in more detail. In our study, the influence of the amendment added to an agricultural soil with different organic wastes containing LASs on organic matter content and nitrogen (N) content evolution and mineralization was studied in field conditions. A completely randomized 3×3 factorial arrangement, representing two sewage sludge types (composted and uncomposted) and three levels of LAS presence (0, 15, and 30 g/m²) in treated soils, was established using field plots (7×2 m); the results are compared with untreated plots. Statistical models based on covariance analysis were used to understand the dynamics of and the main factors influencing carbon (C) and N mineralization in sewage sludge amended–soils in the presence of LAS. LAS seemed to alter nitrogen mineralization, especially the nitrate dynamics.     

Modification of softwood kraft pulp with carboxymethyl cellulose and cationic surfactants

An elemental chlorine-free (ECF)-bleached soft-wood kraft pulp was treated first with a carboxymethyl cellulose (CMC, degree of substitution 0.3, 1% on pulp) and then with alkyltrimethylammonium bromides (alkyl chain lengths of C₁₀ to C₁₆). Surprisingly, the treatment with dodecyltrimethylammonium bromide (C₁₂TAB) markedly increased the internal and tensile strengths of the handsheets prepared from the modified pulp. Environmental scanning electron microscopy (ESEM) showed that these properties could be partly explained by the “rope/gum-like” bridges that were formed between the fibers.     

表面活性剂对植物叶面润湿作用影响的研究

】测定了表面活性剂的动表面张力、在叶面上的吸附速度和接触角,据此分析了它们在叶面上的润湿作用。结果表明,表面活性剂分子碳氢链越短,在界面上的吸附速度越快,接触角越大,在植物叶面上的润湿性能越好。其中,ＳＦＥ在界面上的吸附速度最慢,在植物叶面的润湿作用最差;ＯＰ－１０吸附速度最快,润湿性能最好。利用测定动表面张力及其变化的方法,基本上可以反映表面活性剂水溶液对植物叶面的润湿性能的变化。     

过碳酰胺对土壤中非离子表面活性剂的修复研究

过碳酰胺是一种新型精细化工品,也是一种新型N肥,其应用和开发在国外已得到广泛的研究,而在我国还刚刚起步.为考察过碳酰胺作为一种N肥去除土壤中有机污染物的作用和潜力,将修复与施肥结合,为过碳酰胺应用于环境污染修复提供新的理论依据,特进行了本研究.本文采用室内土培试验等手段,研究了1种酸性土壤中施入过碳酰胺后对2种非离子表面活性剂TritonX-100和Tween80的降解效果.试验结果表明:过碳酰胺对2种非离子表面活性剂都有明显的降解效果,降解速度均是在第2周时较快,此后.随着降解时间的延长,降解速率逐渐下降.8周后1000mg/kg Tween80的残留浓度仅有195.46mg/kg土,降解率高达80%以上.5 mmol/kg的过碳酰胺降解2周后已有明显降解效果,但继续增加过碳酰胺浓度.其降解效果并非相应增加.     

Optimization of lipase-catalyzed synthesis of palm amino acid surfactant using response surface methodology (RSM)

Amino acid surfactants are high-value surfactants which have excellent emulsifying characteristics and minimal toxicity to the living body. Enzymatic synthesis of palm kernel amino acid surfactant was optimized by response surface methodology (RSM) using palm kernel olein (PKO) and l(+)-lysine catalyzed by Lipozyme RM IM. The reaction was performed in batch mode stirred tank reactor (STR) with one multi-bladed impeller. A central composite rotatable design (CCRD) was employed to evaluate the interactive effects of various parameters. The parameters were temperature (A): (40.00–70.00 °C), impeller speed (B): (100.00–400.00 rpm), substrates ratio (C): (1.00–4.00 mmol) and enzyme amount (D): (5.00–8.00 g). The optimum condition derived via RSM at fixed reaction time of 24 h was temperature; 47.50 °C, impeller speed; 323.96 rpm, substrates ratio; 3.25 mmol and enzyme amount; 7.25 g. The experimental yield was 89.03% under the optimum condition, which compared well with the maximum predicted value of 93.77%.     

季铵盐类表面活性剂对细菌ATP提取作用的研究

通过研究几种季铵盐类表面活性剂在ATP生物发光法中不同浓度、不同提取时间对细菌ATP的提取效果,确定了浓度为0．2％的苯扎氯铵（BAC）提取细菌ATP2min,检测发光值效果最佳;与传统的TCA法进行对比,BAC法对细菌ATP的提取率更高。     

Influence of feeding habits of fish on the characteristics of their visceral alkaline proteases with special reference to detergent compatibility

Technical characteristics and detergent compatibility of visceral alkaline proteases of three freshwater fish, namely Labeo rohita, Pangasianodon hypophthalmus and Cyprinus carpio of different feeding habits, were studied. Crude enzyme extract was partially purified by (NH₄)₂SO₄ precipitation and dialysis. The molecular weight was in the range of 20–63 kDa. The enzyme purification folds post‐dialysis were found to be 1.55, 1.81 and 2.17 in case of Rohu, Pangas and Common carp respectively. The alkaline protease from Rohu, Pangas and Common carp exhibited maximum activity at pH 10.0, 9.0 and 11.0 respectively. The enzyme temperature optima observed were 60°C (Rohu and Pangas) and 70°C (Common carp). SBTI and EDTA inhibited more than 90% of the activity at conc. of 50 mM. Exposure of the proteases to non‐ionic surfactants like Tween 20–80 retained about 92%–100% and 76%–100% of their activity at conc. (v/v) of 1% and 5% respectively. Proteases were found less stable in the presence of SDS. There was moderate to lesser influence of H₂O₂ and sodium perborate on the proteolytic activity. The alkaline protease from omnivorous fish was found superior compared to the herbivore and carnivore in respect of pH and temperature optima and stability with detergents and oxidizing agents.     

不同类型表面活性剂对肌酸激酶活力影响研究

本文系统地研究了阴离子Ｃ１２Ｈ２５ＳＯ４Ｎａ（Ｃ１２Ｓ），Ｃ１２Ｈ２５（ＯＣ２Ｈ４）７ＳＯ４Ｎａ（Ｃ１２Ｅ７Ｓ）、阳离子Ｃ１２Ｈ２５Ｎ（ＣＨ３）３．Ｂｒ（Ｃ１２ＮＭｅ３）和非离子Ｃ８Ｈ１７．Ｃ６Ｈ４．（ＯＣ２Ｈ４）１０ＯＨ（ＴＸ－１００）表面活性剂对肌酸激酶（Ｃ．Ｋ．）活力的影响以及变性后的复性，结果表明，Ｃ１２Ｅ７Ｓ和Ｔｘ－１００对Ｃ．Ｋ．的活力破坏较小，Ｃ．Ｋ．经Ｃ１２Ｅ７Ｓ和ＴＸ－１００变性     

表面活性剂改善竹丝板尺寸稳定的研究

针对竹丝板生产存在的问题,探讨添加表面活性剂对改进竹丝酚醛树脂浸渍含量和竹丝板尺寸稳定性的影响.试验结果表明,在选用的3种表面活性剂中,OP-10对酚醛树脂浸渍含量的影响不显著,但可以明显提高竹丝板的尺寸稳定性;与改性剂聚乙二醇PEG-1000同时使用时效果更显著.     

二甲基-正丁基-磺化木质素基氯化铵的合成及性能研究

以麦草碱木质素为原料通过Mannich和磺化反应合成了二甲基-正丁基-磺化木质素基氯化铵(DBSLAC)两性表面活性剂,表征了其结构,考察其在不同pH值溶液中溶解性,并以铜离子为模拟废水考察了其吸附性能,以酸性黑(ATT)和亚甲基蓝为模拟染料废水考察了其絮凝性能。结果表明:傅里叶红外光谱(FT-IR)证明产物中含有季铵根和磺酸根的化学结构,DBSLAC含氮量2.34%。DBSLAC两性表面活性剂对Cu2+的吸附平衡符合Freundlich等温方程,并且在20 mL Cu2+溶液的初始质量浓度为100 mg/L,投加量0.002 g、pH值5.5和吸附时间2 h的条件下对Cu2+的吸附效果最佳,吸附量达262.34 mg/g;在20 mL染料溶液中,对酸性黑ATT(阴离子染料)的絮凝效果在投加量0.03 g、pH值2和染料质量浓度为0.1 g/L时最佳,最大脱色率75.41%;对亚甲基蓝(阳离子染料)的絮凝效果在投加量0.3 g、pH值9和染料质量浓度为0.1 g/L时最佳,最大脱色率97.87%,结果表明DBSLAC可用作重金属离子吸附剂和染料絮凝剂。