利用PCR-DGGE溯源典型农村塘坝饮用水中的污染

以华南地区典型农村塘坝饮用水为研究对象,采用基于大肠杆菌的两种特异性基因(β-D-葡萄糖苷酶编码基因uidA和膜外周磷通道蛋白编码基因phoE)的群体差异分析(PCR-DGGE),对饮用水中的污染情况进行了溯源研究.结果表明,采用富集培养的混合菌体DNA作为模板扩增大肠杆菌特异性基因更加实用.uidA和phoE的引物均...     

Removal of copper ions from aqueous solution by calcium alginate immobilized kaolin

Kaolin has been widely used as an adsorbent to remove heavy metal ions from aqueous solutions. However, the lower heavy metal adsorption capacity of kaolin limits its practical application. A novel environmental friendly material, calcium alginate immobilized kaolin (kaolin/CA), was prepared using a sol-gel method. The e ects of contact time, pH, adsorbent dose, and temperature on Cu2+ adsorption by kaolin/CA were investigated. The Langmuir isotherm was used to describe the experimental adsorption, the maximum Cu2+ adsorption capacity of the kaolin/CA reached up to 53.63 mg/g. The thermodynamic studies showed that the adsorption reaction was a spontaneous and endothermic process.     

Application of magnetic particles modified with amino groups to adsorb copper ions in aqueous solution

A magnetic adsorbent can be easily recovered from treated water by magnetic force,without requiring further downstream treatment.In this research,amine-functionalized silica magnetite has been synthesized using N-[3-(trimethoxysilyl)propyl]-ethylenediamine(TPED) as a surface modification agent.The synthesized magnetic amine adsorbents were used to adsorb copper ions in an aqueous solution in a batch system,and the maximum adsorption was found to occur at pH 5.5 ± 0.1.The adsorption equilibrium data fitted t...     

Archaeal community structure along a gradient of petroleum contamination in saline-alkali soil

The impact of petroleum on archaeal community in salinealkali soils was investigated, which will expand the knowledge of the archaeal population involved in the natural attenuation of hydrocarbons in extreme environments.     

利用铜矿尾砂研制低强度可控性填料

利用铜矿尾砂、粉煤灰、水泥以及加气剂等,混合搅拌成泥浆体,振动成型,制备出低强度可控性填料(CLSM).试验表明:以水泥12.9％、铜矿尾砂(细集料)22.6％、加气剂3.2％、粉煤灰12.9％等工业废弃物,加水48.4％,固液比控制在(14～15):(15～16)之间,制得的CLSM制品,抗压强度0.35～2.00 ...     

铜对草鱼及花鲢的毒性预测：基于生物配体模型

试验配置不同胡敏酸浓度(DOC浓度为0.05、0.5、1、2、4 mg·L-1)下,分别对草鱼及花鲢进行铜的一系列96 h生物急性毒性试验,结果表明DOC浓度与LC50呈正相关关系,此与生物配体模型描述一致.利用两鱼种(Fathead minnow、Rainbow trout)的生物配体模型预测草鱼及花鲢的LC50,得出平均绝对偏差分别为591.2、157.14μg·L-1及728.18、91.24μg·L-1.在生物配体模型(biotic ligand model,BLM)铜形态分布平台下,得到草鱼及花鲢的LA50(以湿重计)依次为10.960nmol·g-1和3.978 nmol·g-1.通过校正草鱼及花鲢的LA50,得出平均绝对偏差依次为280.52μg·L-1和92.25μg·L-1,预测性能显著提高.基于所确立的LA50,通过搜集草鱼及花鲢的毒性数据,预测其LC50,得到平均绝对偏差分别为252.37μg·L-1和50.26μg·L-1,此证实基于生物配体模型的毒性预测具有一定的实用性.     

不同条件下皂苷对污染塿土中Cu、Pb的淋洗修复

为了探讨环境友好型生物表面活性剂皂苷(saponin)对污染塿土中重金属Cu、Pb的淋洗修复效果,采用批次试验方法,研究了皂苷在不同的淋洗时间、质量浓度、p H、淋洗次数及背景电解质强度下对Cu、Pb单一污染塿土和复合污染塿土中Cu、Pb的淋洗效果.结果表明,当皂苷质量浓度为50 g·L-1、p H值为5.0、淋洗时间为240 min、无背景电解质离子共存时,重金属离子通过与皂苷胶团络合,对污染塿土中Cu、Pb的淋洗去除效果达到最大;在单一污染塿土和复合污染塿土中,50g·L-1的皂苷在最佳淋洗条件下对Cu的单次淋洗百分率分别为29.02%和25.09%,对Pb的单次淋洗百分率分别为31.56%和28.03%,同时也显示皂苷对Pb的去除效果比Cu更显著.经过4次淋洗后,在单一污染塿土和复合污染塿土中皂苷对Cu的累积淋洗百分率分别为58.92%和53.11%,对Pb的累积淋洗百分率分别为77.69%和65.32%.单次淋洗前后污染塿土中重金属形态分级结果表明:污染塿土中吸附态、交换态Cu、Pb的质量分数有所增加;碳酸盐结合态、有机结合态和硫化物残渣态的Cu、Pb可得到有效去除.     

掺杂聚乙烯醇的壳聚糖小球对铜离子-腐殖酸的单一和连续吸附行为

以三聚磷酸钠作为离子交联剂,合成了一种掺杂聚乙烯醇的壳聚糖小球,采用SEM和FTIR表征了小球的表面性能及官能团分布情况,进一步研究了这种小球对腐殖酸和铜离子的单独吸附行为、连续吸附行为及两者共存状态下的吸附行为,并通过XPS能谱分析了吸附过程的机理.结果表明:在单独吸附过程中,壳聚糖小球与腐殖酸和铜的作用方式主要是通过静电引力和络合作用;在连续吸附过程中,先吸附了腐殖酸的小球,后续对铜离子的吸附效果变弱;而先吸附了铜离子的小球,后续对腐殖酸的吸附能力变强,说明这种小球在吸附过程中可以被连续使用.而在腐殖酸和铜离子共存的吸附实验中发现,壳聚糖小球除了会吸附溶液中的铜离子和腐殖酸外,还导致它们的聚集沉降.     

Monitoring aromatic hydrocarbon biodegradation by functional marker genes

The development of biological treatment technologies for contaminated environments requires tools for obtaining direct information about the biodegradation of specific contaminants. The potential of functional gene array analysis to monitor changes in the amount of functional marker genes as indicators of contaminant biodegradation was investigated. A prototype functional gene array was developed for targeting key functions in the biodegradation of naphthalene, toluene and xylenes. Internal standard probe based normalization was introduced to facilitate comparison across multiple samples. Coupled with one-colour hybridization, the signal normalization improved the consistency among replicate hybridizations resulting in better discrimination for the differences in the amount of target DNA. During the naphthalene biodegradation in a PAH-contaminated soil slurry microcosm, the normalized hybridization signals in naphthalene catabolic gene probes were in good agreement with the amount of naphthalene-degradation genes and the production of 14CO2. Gene arrays provide efficient means for monitoring of contaminant biodegradation in the environment.     

Causes of change in nitrophytic and oligotrophic lichen species in a Mediterranean climate: impact of land cover and atmospheric pollutants

With the aim of determining the main drivers of changes in nitrophytic and oligotrophic macro-lichen communities in an industrial region with a Mediterranean climate, we considered both land-cover types and atmospheric pollutants. We determined the relation between the abundance of nitrophytic and oligotrophic species with environmental factors considering the distance of influence of land-cover types. The results showed that oligotrophic species decreased in the proximity of artificial areas, barren land and agricultural areas, associated with higher concentrations of NO₂ and Zn, and Ti, probably dust of industrial and agricultural origin. Nitrophytic species were positively related to all the mentioned land-cover types, and with higher concentrations of Fe and N. Magnesium, probably from ocean aerosols, was negatively related to oligotrophic species and positively to nitrophytic.