破络合剂对化学镀镍废水处理的影响

采用不同的破络合剂处理化学镀镍废水,探讨了CaO、CaCl2和BaCl2 3种破络合剂处理化学镀镍废水时,对Ni2＋去除率的影响,同时对CaO联合BaCl2处理化学镀镍废水进行了研究。实验结果表明,CaO、CaCl2和BaCl2的使用量分别为3.0、6.0和4.5 g/L时,Ni2＋去除率分别为32%、19%和99.9...     

铁炭-混凝沉淀-生化处理强酸性染料废水的中试研究

采用铁炭-混凝沉淀-水解酸化-生物接触氧化工艺对强酸性染料废水进行中试处理研究。在铁炭微电解单元主要考察了铁炭比、HRT和曝气量大小对处理效果的影响;在水解酸化单元主要考察了进水pH和HRT对处理效果的影响。通过铁炭微电解和水解酸化,在大幅改善废水的可生化性的同时,还可以有效去除废水的色度、削减有机负荷,以保证后续的生物接触氧化工艺的高效稳定运行。在生物接触氧化单元主要考察了进水浓度、HRT对处理效果的影响。经过组合工艺的处理,最终的出水COD〈75 mg/L,出水色度〈40倍。     

Polychlorinated biphenyls and organochlorine pesticides in local waterbird eggs from Hong Kong: risk assessment to local waterbirds

The contamination status of the marine environment in Hong Kong was studied by measuring concentrations of organochlorine (OC) pollutants (i.e., hexachlorobenzene, aldrin, dieldrin, endrin, mirex, total heptachlor, total chlordane, total DDTs, total PCBs, and total toxaphenes) in the eggs of selected waterbird species from different locations around the city: Little Egret (Egretta garzetta) and Chinese Pond Heron (Ardeola bacchus) from Mai Po Village, Great Egret (Ardea alba) and Black-crowned Night Heron (Nycticorax nycticorax) from A Chau, and Chinese Pond Heron (A. bacchus) from Ho Sheung Heung. The mean concentrations of total PCBs and total DDTs ranged from 191-11 100 ng g⁻¹ lipid and 453-49 000 ng g⁻¹ lipid, respectively. Recent exposure of waterbirds to technical chlordane was found in Hong Kong. The risk characterization demonstrated potential risks to birds associated with exposure to DDE, which was found to cause a reduction in survival of young in Hong Kong Ardeids based on the endpoint in the risk assessment.     

Effects of hydrodynamics on the distribution of trace persistent organic pollutants and macrobenthic communities in Bohai Bay

In recent years, the rapid economic development along Bohai Bay, has brought out continuous increasing of the pollution loads in the Bohai Sea, especially by the large coastal reclamation project, Tianjin Binhai New Area. In the period of 2007-2009, we collected the sediments of the main rivers, estuaries, intertidal zone, and near-shore area of Bohai Bay, and Macrobenthos associated with the marine sediments to assess the influence of hydrodynamics in the coastal environment on the pattern of trace contaminants and the macrobenthic community. Based on data derived from these samples, the levels of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) in sediments followed the order PAHs > OCPs > PCBs > PBDEs. The higher concentrations of PCBs, OCPs, PAHs and PBDEs were found in the estuarine and near-shore environment of the Dagu Drainage River. The spatial distribution of OCPs was different to that of PCBs due to the direction of the velocity field of Bohai Bay in its old and new topography, and the higher water-solubility of OCPs than that of PCBs. The results of the Pearson correlation and the PCA indicate that the medium diameter (MD) of sediments was the predominant factor influencing the distribution of PCBs and OCPs, most sampling sites were characterized mainly by TOC of sediments and biomass of macrobenthos. The results indicate that the distribution of trace contaminants and macrobenthic community in Bohai Bay are mainly affected by the hydrodynamic conditions.     

Reactive transport modeling of column experiments on the evolution of saline-alkaline waste solutions

Leakage of saline-alkaline tank waste solutions often creates a serious environmental contamination problem. To better understand the mechanisms controlling the fate of such waste solutions in the Hanford vadose zone, we simulated reactive transport in columns designed to represent local site conditions. The Pitzer ion interaction module was used, with principal geochemical processes considered in the simulation including quartz dissolution, precipitation of brucite, calcite, and portlandite, multi-component cation exchange, and aqueous complexation reactions. Good matches were observed between the simulated and measured column data at ambient temperature ( approximately 21 degrees C). Relatively good agreement was also obtained at high temperature ( approximately 70 degrees C). The decrease of pH at the plume front is examined through formation of secondary mineral phases and/or quartz dissolution. Substantial formation of secondary mineral phases resulting from multi-component cation exchange suggests that these phases are responsible for a decrease in pH within the plume front. In addition, a sensitivity analysis was conducted with respect to cation exchange capacity, selectivity coefficient, mineral assemblage, temperature, and ionic strength. This study could serve as a useful guide to subsequent experimental work, to thermodynamic models developed for the concentrated solutions at high ionic strength and to other types of waste plume studies.     

泡沫分离法去除废水中微量钴离子

采用泡沫分离法对水中微量钻离子的去除进行了研究,考察了表面活性剂种类及浓度、pH、气流量等因素对钴离子去除率的影响。实验结果表明：当水中钴离子初始质量浓度为10mg／L、采用十二烷基硫酸钠（SLS）做表面活性剂且质量浓度为10mg／L、pH为11．0、气流量为300L／h时,钴离子去除率达97．61％。根据泡沫分离过程与化学反应过程在物理行为上的类似性,引入等效的化学反应常数,对泡沫分离法去除水中钴离子进行了宏观动力学研究。结果表明,该泡沫分离过程可等效为一级反应。     

Adsorption and absorption of polycyclic aromatic hydrocarbons to rice roots

Rice roots and surrounding air, soil and water samples were collected for polycyclic aromatic hydrocarbon (PAH) analysis. The rice roots were separated into lateral roots and nodal roots, and the PAH concentration in the former was found to be higher than that in the latter. In addition, root physiological characteristics including root biotic mass, root lipid content and specific surface area are also discussed. When normalizing the total, adsorption and absorption PAH fractions on a dry root weight basis to root biomass, root lipid, and surface area bases respectively, the differences between PAHs in the two types of roots diminished by 2 to 3 times on average. Results from sequential extraction indicated that PAHs were more easily absorbed by interior rice roots than adsorbed on the surface. In addition, more than 60% of total PAHs accumulated in root tissue for both lateral and nodal roots. However, the results were highly related to the solvent used, extraction time and methodology. Correlation analysis between bioconcentration factors (root over environment) and K(OA), K(OW) showed water to be more significant for PAH adsorption in rice roots than other environmental media.     

在线液膜萃取富集流动注射分光光度法测定水中痕量对硝基苯酚

介绍了选用无毒性的磷酸三丁酯为流动载体,煤油为膜溶剂的支撑液膜萃取体系,建立了支撑液膜在线萃取富集流动注射分光光度法测定水中痕量对硝基苯酚的新方法。通过对实验条件的优化选择,得出该方法的检测限为0．002mg／L,线性范围为0．005mg／L～0．05mg／L。该方法应用于废水中对硝基苯酚的检测,结果满意。     

聚乙烯微塑料对土壤养分和酶活性的影响

微塑料污染对土壤生态系统的威胁引起了广泛关注.为了明确聚乙烯微塑料对土壤性质的影响,通过为期4个月的土壤培养试验,探究不同质量分数（1 %、2.5 %、5 %）和粒径（30目、100目）聚乙烯微塑料对土壤化学性质、养分含量和酶活性的影响.结果表明:①100目2.5 %和5 %微塑料处理显著降低了土壤pH,不同质量分数和粒径聚乙烯微塑料添加对土壤电导率影响不显著.②相比于CK,添加微塑料会不同程度降低土壤速效钾、有效磷和硝态氮含量.添加100目微塑料显著增加了土壤有机质和铵态氮含量.③当微塑料粒径为100目时,相比于CK,不同质量分数处理均显著提高了土壤过氧化氢酶和碱性磷酸酶活性,5 %处理显著降低了土壤蔗糖酶活性.④土壤性质的变化受微塑料质量分数和粒径影响,质量分数越高、粒径越小,影响越显著.综上,聚乙烯微塑料对土壤性质的影响没有预期的明显,未来研究应重点关注不同影响所涉及的机制问题.     

控制在用车排放恶化的有效措施

针对我国在用车排放比较严重的现状，我们认为：短期内易于实现，花费不高，不用对现有车辆作重大技术变动的有效措施是完善在用车Ｉ／Ｍ计划和进行在用国的加速淘汰工作。而且，对于用率和高污染车辆，完善的Ｉ／Ｍ计划也是更有效控制机动车排放污染所必需的。