TMA改性粘土矿物对模拟地下水中苯系物的吸附

用短链季铵盐阳离子表面活性剂四甲基铵离子（ＴＭＡ）改性膨润土和凹凸棒土,研究它们对模拟地下水中苯系物的吸附作用。二种ＴＭＡ改性粘土矿物均可以有效地吸附模拟地下水中的苯系物,吸附机理较复杂,主要以表面吸附为主。     

Lignin and holocellulose from coir pith involved in trimethylamine (fishy odor) adsorption

Coir pith is a highly potential adsorbent for adsorbing trimethylamine(TMA). It harbors a higher adsorption capacity for TMA compared to commercial activated carbon(CAC). It was found that lignin and holocellulose extracted from coir pith played an important role in TMA adsorption. Lignin itself had the highest TMA adsorption capacity(269.01 mg/g)followed by holocellulose(75.43 mg/g), coir pith(14.3 mg/g) and CAC(10.26 mg/g),respectively. The pseudo-first-and second orders were applied to the kinetic data. For the adsorption of TMA by coir pith, the best fit was achieved by the pseudo-second order.Thermodynamic studies showed an endothermic and physico-chemical adsorption process between TMA and the coir pith. TMA desorption study suggested that only 14%–47% of TMA was desorbed with distilled water. In addition, Fourier transform-infrared(FT-IR) spectra showed that C–H bond(methyl group), C–O bond from phenolic alcohol and C–O bond from tertiary alcohol in lignin and holocellulose were involved in TMA adsorption. Coir pithbased filter showed high TMA adsorption efficiency(98%) and kept constant for more than48 days in a continuous system. Pilot scale experiment, coir pith beads filter could be succesfully applied as a packing material for TMA removal. Therefore, coir pith can be used as a promising packing material for TMA treatment at contaminated site.     

Sorption and cosorption of organic contaminant on surfactant-modified soils

Three kinds of soils were modified with the cationic surfactants, hexadecyltrimethylammonium (HDTMA) bromide and tetramethylammonium (TMA) bromide to increase their sorptive capabilities. Sorption of chlorobenzene in simulated groundwater by these soils was investigated. HDTMA-modified soil has a higher ability to sorb chlorobenzene from simulated groundwater than unmodified soil. TMA-modified soil did not show the superiority. HDTMA thus can be used to modify soil to improve its sorption capability. Cosorption of chlorobenzene in simulated groundwater in the absence or presence of nitrobenzene and dichloromethane on HDTMA-modified soil was also investigated. Nitrobenzene facilitated sorption of chlorobenzene on all HDTMA-modified soil. Dichloromethane did not influence the sorption of chlorobenzene by HDTMA-modified soil. The results suggest that HDTMA-modified soil is a highly effective sorbent for chlorobenzene and multiple organic compounds did not impede the uptake of chlorobenzene.     

生物法处理含氮硫无机有机恶臭气体研究

生物滴滤塔处理含三甲胺(TMA)和二硫化碳(CS)2的双组分含氮硫无机有机混合恶臭气体的研究结果表明,生物法能有效去除含三甲胺和二硫化碳的混合恶臭气体,三甲胺(TMA)和二硫化碳(CS)2的去除效率分别可达99.8%、93.8%,生物脱臭装置对恶臭污染物的改变具有很强的适应性,对新恶臭污染物质的进入有较好的适应性,具有较好的抗冲击负荷性,运行稳定,能适应非连续性生产的要求。污染物之间没有明显的相互抑制作用,进气浓度的提高对三甲胺的生物降解效率影响微弱,对二硫化碳的生物降解效率影响较大。适宜空床停留时间为20.6 s,三甲胺去除几乎不受循环液pH变化的影响,二硫化碳的去除则在pH=7～8.3时较高。生物降解动力学研究表明,生物塔对三甲胺的最大去除能力优于二硫化碳,对二硫化碳的亲和力优于三甲胺。