线性判别分析对舟山海洋站降水中常量阳离子含量的年度、季节特征分析

通过对舟山站点2002/2003年度降水中的6种常量阳离子H⁺、NH₄⁺、K⁺、Na⁺、Ca²⁺、Mg²⁺近2a的连续观测,采用稳健统计分析对浓度范围及变化趋势进行了描述.利用线性判别分析对实验数据进行降维处理,得到线性判别曲面,对样本点在新正规变量空间的时间性分布特征进行了描述,依据正规变量的线性组合,解释了决定该样本点时间性特征分布的主要阳离子影响因素,并对造成异常样品点的影响因素进行了分析.     

Effects of bile salts and divalent cations on the adsorption of norfloxacin by agricultural soils

The effects of bile salts （sodium cholate and sodium deoxycholate, 0-20 mmol/L）, divalent cations （Ca^2＋, Mg^2＋, Cu^2＋ and Zn^2＋, 0-20 mmol/L） or pH （3.0-10.0） on the adsorption of norfloxacin by three selected soils （Paddy_H, Paddy_G and Red_J） were systematically studied. Soil adsorption of norfloxacin follows a pseudo second-order kinetics model, and the maximum adsorption capacity has been determined from the nonlinear fit of the Langmuir isotherm model to be 88.8, 88.1 and 63.0 μmol/g for the adsorption onto Paddy_H, Paddy_G and Red_J, respectively. The results indicate that norfloxacin has a high adsorption affinity for the agricultural soils tested and that the organic content of these soils have at least a slight influence on this adsorption. The adsorption of norfloxacin to soils was strongly dependent on pH and exhibited a maximum at approximately pH 6. The presence of divalent cations prominently suppressed the adsorption of norfloxacin by paddy soils, which followed an order of Cu^2＋ 〉 Mg^2＋ 〉 Ca^2＋ 〉 Zn^2＋, and by red soil, which followed an order of Cu^2＋ 〉 Zn^2＋ 〉 Ca^2＋ 〉 Mg^2＋. The adsorption of norfloxacin （by the soils studied） sharply decreased as the amount of bile salts was increased. For uncharged norfloxacin at environmentally relevant pH values, such factors as soil type, exogenous divalent cations and macromolecules significantly altered the environmental fate and transport of norfloxacin between aquatic and soil interfaces.     

阳极内添加阳离子交换树脂提升辊压“三合一”膜电极MFC性能

阳极-隔膜-阴极的"三合一"膜电极结构能够最大程度减小阴阳极间距,提高微生物燃料电池(microbial fuel cell,MFC)的输出功率.为进一步提高MFC性能,本研究使用非贵金属材料构建了辊压"三合一"膜电极系统,其欧姆内阻降低至3~5Ω.以乙酸钠为底物,MFC的最高功率密度达到446 m W·m-2.向阳极内添加固体小球(如聚苯乙烯球和玻璃微球)可在辊压过程中增加阳极表面和内部的大孔,强化电解液向阴极的传递从而使MFC的功率密度提升10%.添加阳离子交换树脂能够进一步强化阳极内部的质子传递,提高阴极电位,从而将功率密度提升至543 m W·m-2.此外,阳极内添加阳离子交换树脂还可提高电池运行的稳定性和库仑效率.     

溶解氧对HLB-MR反应器内有机物的生物絮凝影响

为了研究溶解氧（DO）对高负荷生物絮凝-膜反应器（HLB-MR）内有机物生物絮凝规律的影响,采用平行对比实验,考察了不同DO条件下反应器内有机物的生物絮凝效果、胞外聚合物（EPS）含量、金属阳离子浓度和微生物群落结构.结果表明：DO浓度分别为1~2mg/L和6~8mg/L时,HLB-MR反应器的絮凝效率分别为83%和89%,两反应器内上清液的浊度差别也进一步证实,较高的DO浓度下,反应器的生物絮凝效果更好.DO浓度在6~8mg/L时,HLB-MR反应器内结合态EPS和自由态EPS的含量分别为15.64mg/（g·VSS）和8.71mg/L,两者均显著高于DO为1~2mg/L时的11.83mg/（g·VSS）和6.56mg/L,反应器浓缩液中镁和铝的浓度也均明显高于低DO浓度时所对应的值,这说明在高DO条件下,有更多的EPS与金属阳离子结合而固定在污泥基质中,促进了生物絮凝.高通量测序表明,DO浓度分别为1~2mg/L和6~8mg/L时,HLB-MR反应器内细菌的群落结构差异明显,高DO浓度反应器底泥中Actinobacteria和Saccharibacteria的相对丰度较高,可能对生物絮凝有促进作用.     

锰氧化物-阳离子交换树脂复合材料的制备及其对水中重金属的吸附性能

采用原位沉淀-空气氧化法将锰氧化物负载于大孔强酸性阳离子交换树脂D001上,制备出一种新型锰氧化物-阳离子交换树脂复合材料Mn-D001,并对该材料吸附水中Pb2+、Cd2+、Cu2+的性能进行了深入研究.TEM、XRD以及XPS的分析结果表明,负载的锰氧化物以MnO2的形态存在.基于单一金属离子静态吸附的一元体系实验表明,Mn-D001比D001对Pb2+、Cd2+、Cu2+具有更高的吸附选择性,在高浓度竞争离子Ca2+、Mg2+、Na+共存的情况下,仍能保持较高的重金属去除率;Mn-D001对Pb2+、Cd2+、Cu2+的吸附行为符合准一级动力学模型(R2>0.99)和Langmuir吸附等温线模型(R2>0.99).在温度为303 K时,Mn-D001对3种重金属的饱和吸附容量可分别达到476.19 mg.g-1、243.90 mg.g-1及196.08 mg.g-1,优于原有树脂D001.基于复合重金属离子竞争吸附的二元、三元体系的实验表明,Mn-D001对3种重金属的吸附能力顺序为Pb2+>Cu2+>Cd2+,吸附能力由原有树脂D001以及负载的锰氧化物的性质共同决定.     

废钻井液固液分离处理用化学剂性能评价

为了满足废钻井液固液分离处理要求,通过试验优化出两种无机破胶剂,同时对该处理用化学剂的性能进行了详细的评价。结果表明,所合成阳离子聚合物与无机破胶剂配伍使用可以保证滤出液具有较好的透明性,且具有良好的协同增效作用。用滤出液配制处理液进行反复处理,效果同用清水配制处理液处理相当,可节约处理费用。     

有机膨润土对对硝基苯酚吸附性能的研究

以溴化十六烷基三甲铵(CTMAB)和溴化十六烷基吡啶(CPB)两种表面活性剂对钠基膨润土进行有机改性,研究了改性后的有机膨润土的用量、介质pH值、作用时间、溶液中对硝基苯酚的浓度等因素对膨润土去除对硝基苯酚的影响.结果表明:同一浓度条件下,CTMAB-有机膨润土对对硝基苯酚的去除率和吸附量均比CPB-有机膨润土高;当对硝基苯酚溶液pH在2-10范围内,2种有机膨润土对对硝基苯酚的吸附性能变化不大,但当pH上升到12时,2种有机膨润土对对硝基苯酚去除率分别下降20.5%和36.2%.2种有机膨润土对对硝基苯酚的吸附可用Freundlich方程加以描述.     

活性污泥胞外聚合物提取方法的研究

对两种不同来源的活性污泥中EPS的提取效率进行了研究,采用的提取方法有NaOH法,阳离子交换树脂法（CER法）,加热法和离心法。结果表明,CER法是两种污泥EPS提取中最有效的方法。经过16h的提取,EPS中DNA的含量分别为0．73％和1．61％,这表明EPS的提取没有受到胞内物质的污染。两种污泥EPS的提取量分别为74mg／gVSS和80mg／gVSS,其中多糖和蛋白质是EPS的主要成分。在研究中,CER法最佳提取时间为8h,高搅拌强度和CER投加量都有利于EPS提取量的增加。     

Effect of background electrolytes on the adsorption of nitroaromatic compounds onto bentonite

To further elucidate interaction of nitroaromatic compounds with mineral surface, the sorption of m-dinitrobenzene (m-DNB) and nitrobenzene to original bentonite in aqueous solution containing di erent electrolytes (i.e., KCl, NH4Cl, CaCl2 and Tetramethylammonium bromide (TMAB)) was studied. The sorption of m-DNB was greatly enhanced with the presence of KCl and NH4Cl, while little influence was observed with CaCl2 and TMAB, following the order of KCl > NH4Cl TMAB, CaCl2, or DI water. For nitrobenzene, sorption enhancement only occurred at high nitrobenzene concentrations in the presence of KCl, and the solute equilibrium concentration at inflexion point was lowered with increasing KCl concentration. These sorption enhancements were significantly promoted with the increase of electrolyte concentration. The salting-out e ect is insu cient to account for the sorption enhancement by original bentonite with increasing KCl or NH4Cl concentration. X-ray di raction patterns of bentonite suspensions indicated that the sorption enhancement of m-DNB was attributed to the intercalation of K+ or NH4 + into bentonite interlayer and then dehydration with m-DNB to form inner-sphere complexes, which caused previously expanded bentonite interlayers to collapse in aqueous suspension, thus further enhanced the interaction of phenyl with siloxane surface. In comparison, the sorption enhancement of NB is attributed to the formation of outer-sphere complexes with K+ at high solute-loadings (> 200–400 mg/kg). The sorption of m-DNB to initially modified TMA+-bentonite and K+-bentonite was almost the same as respective sorption to original bentonite in solution containing TMA+ and K+.