Adsorption and desorption of iodine by various Chinese soils: I. Iodate

In order to assess the adsorption of iodate by different soils from China, a series of batch experiments were conducted. It was found that soils rich in iron oxide had high affinity for iodate. Iodate adsorption isotherms could be well fitted with both Langmuir and Freundlich equations. Iodate adsorption by 20 different soils from China revealed that iodate adsorption was significantly correlated with soil organic matter negatively and positively with free iron oxide contents. At initial concentration of 4 mg I L(-1), iodate adsorption ranged between 9 and 34 mg kg(-1) soil. No correlation between iodate adsorption and cation exchange capacity and soil pH was found. For a single soil, there was a significant linear relationship between the amounts of iodate adsorbed and desorbed, but for a group of different soils, the relationship between the amounts of iodate adsorption and desorption followed a nonlinear relationship, the deviation mainly occurred at high adsorption side. The relationship between K(d) and free aluminum oxide and free iron oxide contents showed an exponential relationship for various soils with exception of the soil from Hetian in Xinjiang.     

模拟酸雨对峨眉山冷杉林土壤特性的研究

本文采用模拟酸雨方法,考察了峨眉山不同区域冷杉生长正常区和受害区的土壤样品,在酸沉降影响下,土壤特性所发生的改变,测定了土壤酸碱度及主要元素含量。同时以未受到酸沉降侵蚀的贡嗄山土样作为对照点,探讨由酸沉降所造成的土壤酸化,进而引起土壤特性改变与冷杉生长间的关系。     

对氯酚的生物降解及其污染土壤的生物修复探索

从天津农芭厂混合土壤中分离到一株能够降解对氯酚的黄单胞菌Ｄ－１,在此基础上,研究了该菌株对对氯酚的降解特性和将Ｄ－１菌株加入模拟对氯污染土壤中的生物修复试验。     

油田污染土壤中石油烃类微生物及其降解基因的分布

以原油为唯一碳源,运用传统分离培养法,从中国江苏省淮安市金南油田石油污染土壤中筛选出9株具有原油降解功能的菌株并分别命名为JN1~JN9。对其进行形态观察、生理生化实验和分子生物学鉴定,最终确定其分别隶属于Lysinibacillus、Pseudomonas、Raoultella等5个菌属;在适宜条件下进行降解实验,9株菌对原油的降解率最高可达到32.63%;进一步对9株菌进行质粒和基因组上原油降解基因的分析,结果表明,GSTs基因广泛分布在其中8株菌的基因组上,同时JN1、JN3、JN4的质粒上也检测到了GSTs基因; alkB基因分别在7株菌的基因组中和2株菌的质粒检出;LmPH基因仅在JN9的基因组上检出。利用分子生物学手段对石油降解菌降解基因的分布的初步研究结果,可为原油污染场地的微生物修复提供理论依据。     

Synergistic solubilization of polycyclic aromatic hydrocarbons by mixed anionic-nonionic surfactants

Water solubility enhancements of naphthalene (Naph), acenaphthylene (Acen), anthracene (An), phenanthrene (Phen) and pyrene (Py) by micellar solutions of single and mixed anionic-nonionic surfactants were measured and compared. Effects of typical inorganic ions, such as NH(4)(+), Na(+) and Mg(2+) coexisted with the organic pollutants (in soils) on water solubilities of polycyclic aromatic hydrocarbons (PAHs) in the presence of single and mixed surfactants were also investigated. Solubilities of PAHs in water are greatly enhanced in a linear fashion by each of Triton X-100 (TX100), Triton X-305 (TX305), Brij 35, and sodium dodecyl sulfate (SDS). Solubility enhancement efficiencies of surfactants above the critical micelle concentration (CMC) follow the order of TX100>Brij 35>TX305>SDS. PAHs are solubilized synergistically in mixed anionic-nonionic surfactant solutions, especially at low surfactant concentrations. The synergistic power of the mixed surfactants is SDS-TX305>SDS-Brij 35>SDS-TX100. Synergistic effect of a given mixed-surfactant solution on different PAHs also appears to be linearly related to the solute logK(ow). The noted synergism for the mixed surfactants is attributed to the formation of mixed micelles, the lower CMC of the mixed-surfactant solutions, and the increase of the solute's molar solubilization ratio or micellar partition coefficients (K(mc)) because of the lower polarity of the mixed micelles. Suitable quantity of inorganic cations can enhance the solubilization capacities of anionic-nonionic mixed surfactants, the effect being Mg(2+)>NH(4)(+)>Na(+). The water solubility of pyrene was slightly increased by anthracene and significantly increased by 1,2,3-TCB in the presence of SDS-Brij 35. Mixed surfactants may improve the performance of surfactant-enhanced remediation of soils and sediments by decreasing the applied surfactant level and thus the remediation cost.     

Fenton试剂法预处理发酵甘油生产提取废水

采用Fenton试剂预处理高浓度难降解发酵法甘油生产提取废水。研究了pH、Fe2 + 、H2 O2 、反应时间和H2 O2 投加次数对废水COD去除效果的影响。结果表明 ,通过Fenton试剂氧化可使废水中的COD值从 135 0 0mg/L降至 4 0 30mg/L ,COD去除率达到 70 1%。废水的BOD5/COD值从 0 2 0 2提高至 0 5 6 8,可生化性得到较大提高 ,为后续处理创造了条件。研究成果为发酵法甘油生产提取废水的预处理提供了一种非常有效的方法。     

南开菊酯微生物降解的研究

南开菊酯(高效反体氯氰菊酯),是一种新型广谱杀虫剂,经研究可被微生物降解。其溶液中细菌总数的消长,与其降解速率呈正相关关系,说明南开菊酯可被微生物分解利用,在研究土壤混合菌对其降解作用的同时,发现筛选出优势菌株(NK102)。     

MnO2.CuO／Al2O3催化剂上CO的常温催化氧化研究

本文研究了CO常温氧化的催化剂——MnO_2·CuO/Al_2O_3。考察了活性组分MnO_2,CuO的相对百分含量,浸渍溶液的酸度、焙烧温度、反应温度等因素对催化剂活性的影响。发现催化剂的活性与其差热分析的脱水峰及分解反应(MnO_2→Mn_2O_3)的峰温存在一定的对应关系。     

稻田环境与生物多样性实证研究

通过对浙江省安吉县的调查发现,在自然生态环境相似的两个自然村中,以农业为基础产业的禹山坞村稻田及其环境中水栖无脊椎动物、畦畔和沟渠植物的种类和数量多于以工业为主导产业的北村,稻田杂草和秋季稻田天敌的种类和数量少于北村。研究分析表明,稻田及其环境的生物种类和数量与农业生态环境质量的优劣及化肥、农药、除草剂的施用量密切相关。