Adsorption of Ammonium and Heavy Metal Ions on Industrial Vermiculite from the Yuli Mine in Xinjiang, China

The present work discusses the mineralogy, saturated adsorption of ammonium and adsorption of heavy metal ions （Cu^2＋, Pb^2＋ and Zn^2＋） on industrial vermiculite samples from the Yuli Mine in Xinjiang Autonomous Region. The saturated adsorption capacity of ammonium and the affection factors of adsorption of Cu^2＋, Pb^2＋ and Zn^2＋ are discussed on the basis of the mineralogical characteristics of the industrial vermiculite samples. The saturated adsorption capacities of ammonium are between 56.02 and 98.42 mmol/100g. The time of adsorption equilibrium is about 30-60 min, and the pH values and concentration of the ion solution significantly affect the adsorption capacities of the heavy metal ions. The adsorption capabilities of the heavy metal ions on industrial vermiculite are almost the same in the low ion concentration solutions, characterized by a sequence of Zn^2＋〉Pb^2＋〉Cu^2＋ for adsorption capacity in solutions with relatively high ion concentration. The results have practical significance for the application of the industrial vermiculite to treating wastewater containing ammonium or heavy metal ions.     

相转移催化合成增塑剂邻苯二甲酸丁苄酯的研究

以CTMAB为相转移催化剂，苯酐、正丁醇和苄氨为原料合成BBP的新方法。通过设计正交实验，对原料配比、反应时间、催化荆用量、pH值和加水量等影响因素以及催化荆的回收利用进行了研究。实验结果表明，苯酐：正丁醇：CT．MAB：苄氨为1：1．33：0．04：1．2，pH值为9，反应时间为3h，反应过程中的加水量为1％时最高酯产率可达到80％以上。本方法操作简单，耗时少，成本低，催化荆可回收利用，产品质量好，无“三废”污染，并易于工业化生产。     

Experimental and Modelling Approaches for the Assessment of Chemical Impacts of Leachate Migration from Landfills: A Case Study of a Site on the Triassic Sandstone Aquifer in the UK East Midlands

Current risk-based methods for assessing the effects of landfill leachate migration on groundwater resources are conservative and generalised. Cost-effective and practical strategies are required which can robustly determine the potential for contaminant attenuation on a site-specific basis. In this paper laboratory column experiments and reactive transport modelling are evaluated as a combined approach for assessing the chem’ical impact of leachate migration in the Triassic Sandstone aquifer. The results are compared with field data for a landfill in the East Midlands. Columns of aquifer sandstone were flushed sequentially with groundwater, followed by acetogenic or methanogenic leachate to simulate chemical interactions occurring during leachate loading episodes. The key contaminants in leachate (NH₄, heavy metals, organic fractions) were attenuated by ion exchange, redox reactions, sorption and degradation. These processes produce a consistent hydrochemical signature which may help identify the extent of leachate migration in the aquifer. The laboratory results largely replicate those found in the field system, and the behaviour of inorganic contaminants during leachate flushing of the aquifer columns can be described by the reactive transport model. The experimental and modelling approach presented represents a powerful tool for risk assessment and prediction of leachate contaminant fate at unlined and lined landfills.     

裙带菜(Undaria pinnatifida)配子体对氨态氮和硝态氮的吸收利用比较

本文对裙带菜(Undaria pinnatifida)配子体丰富培养的氮源进行了研究,结果发现裙带菜配子体能够有效利用氨态氮和硝态氮进行扩增,在30μmol/L氮离子浓度条件下,裙带菜配子体的日生长率能达到25%,可以满足配子体快速扩增的需要。裙带菜配子体在同时含有硝态氮和氨态氮的培养液中培养时,同时吸收两种氮源,并没有出现相互抑制的现象;配子体对氨态氮的吸收速率略大于硝态氮的吸收;对裙带菜配子体的氮吸收速率进行了测定,吸收速率最高分别可达24.3μmol/(g·h)和20.73μmol/(g·h),吸收速率随着氮浓度的增加而升高。     

不同链长烷基季铵离子在蒙脱石层间域内排列方式的对比

选用含不同烷基长链的三种季铵盐——十二烷基三甲基溴化铵(DDTMAB)、十四烷基三甲基溴化铵(TDTMAB)、十六烷基三甲基溴化铵(HDTMAB)，对河北钠交换蒙脱石进行了有机柱撑实验，以X射线衍射分析方法对实验产物进行了对比研究。结果表明，由于烷基链中所含的碳原子数目不同，三种长链季铵离子对蒙脱石的柱撑效果不同，DDTMA^ 在蒙脱石层间域内可形成平卧单层、平卧双层和假三层三种不同排列方式；TDTMA^ 与DDTMA^ 在低浓度条件下形成的前两种排列方式相同，而第三种则不同，为倾斜单层排列；HDTMA^ 有机柱撑产物中除了具有前两者的排列方式外，还具有倾斜双层排列方式。不同排列方式的复合产物可以多相共存。此外，随着柱撑剂浓度的增加，三种长链烷基季铵离子在蒙脱石层间域内的排列方式及其演化是不同的。     

虾头透明质酸酶的研究

以中国对虾Ｐｅｎａｅｕｓｃｈｉｎｅｎｓｉｓ虾头经处理，得到虾头透明质酸酶酶液，再经沉淀、硫酸铵反抽提、ＤＥＡＥ－纤维素提取和ＳｅｐｈａｄｅｘＧ－７５凝胶层析。纯化倍数达７２０倍，比活８４０ｕ·ｍｇ－１蛋白。该酶最适ｐＨ为４．５，最适温度为５０℃。     

氯化铵浸取纤蛇纹石动力学研究

较低的矿物溶解率和反应剂的不可循环利用是CO2矿物封存发展的两大难题。针对这些问题,本文提出了一种新的以可循环的NH4Cl溶液作为中间媒介的CO2矿物封存工艺,并系统地研究了蛇纹石在氯化铵溶液中的液-固两相的反应动力学。实验研究发现:(1)纤蛇纹石的浸取符合Elovich模型,浸取过程基本在1h左右完成,在100℃、5mol/L氯化铵溶液中,纤蛇纹石的浸取率达到12.67%;(2)温度对纤蛇纹石初始反应速率的影响显著,温度越高,反应速率越快;(3)当氯化铵浓度在1~5mol/L范围内变化时,它对镁离子浸取率的影响不明显,反应速率随着浓度的升高而有所增加;(4)本实验反应表现出来的活化能大小为129.56kJ/mol。      

Flume simulation of wave-induced release of internal dissolved nitrogen in Taihu Lake, China

A wave flume simulator was used to study internal nitrogen release from the surface sediment collected from Taihu Lake,China.Particulate nitrogen concentrations were positively correlated with the concentrations of suspended solids,primarily from surface erosion related to the shear stress and duration of wave action.In response to 4 cm-and 10 cm-high wave production representing waves generated in Taihu Lake by gentle and gusty winds,respectively,the mean dynamic release rate of ammonium(NH+4) from the sediment to the overlying water was 1×10-3 mg/(m2.s) and the NH4+ concentration in the overlying water increased by 0.016 mg/L,indicating that waves resulting from strong wind can induce the rapid release of dissolved nitrogen from Taihu Lake sediments.The decrease in interstitial NH+4 concentrations at all sediment depths was associated with an increase in NH4+ concentrations in the overlying water by 0.01 mg/L,showing that sediment below the eroded layer was the main source of internal nitrogen release.Changes in the interstitial dissolved oxygen and NH+4 concentrations showed that wave-induced pore water movement can greatly increase the diffusion rate,and that these effects can influence the sediment to a depth of at least 15 cm.Diffusion induced by pore water movement may be very important for the formation of an active sediment layer in Taihu Lake.     

基于次溴酸钠氧化-氨基磺酸还原测定沉积物15N加富培养样品中的15NH+4的方法探索

沉积物中的异化硝酸盐还原过程是海洋中活性氮转化的关键过程之一.不同于反硝化和厌氧铵氧化,异化硝酸盐还原为铵(DNRA)是将硝酸盐直接还原为铵,而不是以氮气的形态移除,这有可能会加重水体富营养化和缺氧.目前测定沉积物中异化硝酸盐还原过程的主要手段是15N标记培养技术.为了准确评估DNRA的潜在速率,首先要准确测定加富样品...