石油化工业对周边土壤中金属元素的影响分析

在黄岛石油化工区周边采集土壤样品27个,测定土壤中As、Cd、Cr、Cu、Hg、Ni、Pb、Zn等元素,并运用统计分析、土壤质量综合指数法对测定结果做系统分析。结果表明,除As外,黄岛石油化工区周边土壤中Cd、Cu、Cr、Hg、Ni、Pb、Zn的测定均值均超过青岛市土壤背景值。Cd、Pb、Zn空间分布大体一致,测定值最高的地方均是离石油化工区最近的地方。Cr、Cu、Ni离石油化工区越远,测定值越低。而Hg则相反,离石油化工区越远测定值越高。黄岛石油化工区周边土壤不宜用作农用地,除1处不宜用作建设用地Ⅰ类外,其他均可作为建设用地Ⅰ类和Ⅱ类。     

不同组织碳、氮元素含量和同位素分馏特征研究—以抚仙湖草鱼、鱇浪白鱼为例

结合抚仙湖浮游植物、水生植物等样品,对野生植食性草鱼(Ctenopharyngodon idellus)31个组织和野生肉食性鱇浪白鱼(Anabarilius grahami)17个组织样品碳、氮元素含量和稳定同位素比值(δ13C、δ15N)进行了对比分析.结果显示,鱼类不同组织的碳稳定同位素分馏效应显著,草鱼不同组织...     

Effects of pre-ozonation on organic matter removal by coagulation with IPF-PACI

Ozone plays an important role as a disinfectant and oxidant in potable water treatment practice and is increasingly being used as a pre-oxidant before coagulation. The purpose of this study is to obtain insight into the mechanisms that are operative in pre-ozonized coagulation. Effects ofpre-ozonation on organic matter removal during coagulation with IPF-PAC1 were investigated by using PDA （photometric disperse analysis）, apparent molecular weight distribution and chemical fractionation. The dynamic formation of flocs during coagulation process was detected. Changes of aquatic organic matter （AOM） structure resulted from the influence of pre-ozonation were evaluated. Results show that dosage of O3 and characteristics of AOM are two of the major factors influencing the performance of O3 on coagulation. No significant coagulation-aid effect of O3 was observed for all experiments using either A1C13 or PAC1. On the contrary, with the application of pre-ozonation, the coagulation efficiency of A1C13 was significantly deteriorated, reflected by the retardation of floc formation, and the removal decreases of turbidity, DOC, and UV254. However, if PACl was used instead of AlCl3, the adverse effects of pre-ozonation were mitigated obviously, particularly when the O3 dosage was less than 0.69 （mg O3/mg TOC）. The difference between removals of UV254, and DOC indicated that pre-ozonation greatly changed the molecular structure of AOM, but its capability of mineralization was not remarkable. Only 5% or so DOC was removed by pre-ozonation at 0.6--0.8 mg/L alone. Fractionation results showed that the organic products of pre-ozonation exhibited lower molecular weight and more hydrophilicity, which impaired the removal of DOC in the following coagulation process.     

Metal (Cu, Cd and Zn) removal and stabilization during multiple soil washing by saponin

The influence of multiple saponin washing on copper, cadmium and zinc removal and stability in three types of soils (loamy sand, loam, silty clay) was investigated. Distribution of metals and their mobility measured as the ratio of exchangeable form to the sum of all fractions in soils was differential. After single washing the highest efficiency of metal removal was obtained in loamy sand (82-90%) and loam (67-88%), whereas the lowest in silty clay (39-62%). In loamy sand and loam metals had higher mobility factors (44-61% Cu, 60-76% Cd, and 68-84% Zn) compared to silty clay (9% Cu, 28% Cd and 36% Zn). Triplicate washing led to increase both efficiency of metal removal and percentage content of their stable forms.In consequence, fractional patterns for metals before and after treatment changed visibly as a result of their redistribution. Based on the redistribution index, the most stable metal (mainly in residual and organic fractions) after triplicate washing was Cu in loamy sand and loam. For silty clay contaminated with Cd, effective metal removal and its stabilization required a higher number of washings.     

Fungal biodegradation of CCA-treated wood and removal of its metal components

In the present study, 5 isolates of brown-rot fungi were used for fungal bioprocessing (FB) of chromated copper arsenate (CCA)-treated wood wastes: Antrodia vaillantii SEL8501, Fomitopsis palustris TYP0507 and TYP6137, and Crustoderma sp. KUC8065 and KUC8611. The isolates showed notable capacity for the degradation of treated wood and removal of CCA components via the American Wood Protection Association soil block test. Among them, Crustoderma sp. KUC8611 effectively decayed the treated wood, causing a mass loss of up to 60%. F. palustris caused extensive leaching of CrO₃ of up to 79% and As₂O₅ of up to 87%, but only moderate leaching of CuO of up to 50%. This high capacity for removal of CrO₃ and As₂O₅ showed a strong logarithmic relationship with the amount of oxalic acid produced in the decayed wood. The majority of metals removed from treated wood during the decay process were deposited in the soil and feeder strip. Further investigation will be required to establish the capability of selected fungi for FB of full-sized lumber treated with CCA.     

Heavy metal pollution status in surface sediments of Swan Lake lagoon and Rongcheng Bay in the northern Yellow Sea

The national ‘Shandong Peninsula Blue Economic Zone Development Plan’ compels the further understanding of the distribution and potential risk of metals pollution in the east coast of China, where the rapid economic and urban development have been taken off and metal pollution has become a noticeable problem. Surface sediments collected from the largest swan habitat in Asia, the Swan Lake lagoon and the surrounding coastal area in Rongcheng Bay in northern Yellow Sea, were analyzed for the total metal concentrations and chemical phase partitioning of five heavy metals (Cu, Zn, Pb, Cd, and Cr). Metal contents in the studied region have increased significantly in the past decade. The speciation analyzed by the sequential extraction showed that Zn and Cr were present dominantly in the residual fraction and thus of low bioavailability, while Cd, Pb and Cu were found mostly in the non-residual fraction thus of high potential availability, indicating significant anthropogenic sources. Among the five metals, Cd is the most outstanding pollutant and presents high risk, and half of the surface sediments in the studied region had a 21% probability of toxicity based on the mean Effect Range-Median Quotient. At some stations with comparable total metal contents, remarkably different non-residual fraction portions were determined, pointing out that site-specific risk assessment integrating speciation is crucial for better management practices of coastal sediments.     

Roles of pyrolysis on availability,species and distribution of Cu and Zn in the swine manure: Chemical extractions and high-energy synchrotron analyses

Animal manures generally contain high levels of heavy metals that may pose a significant threat to soil and groundwater qualities. Pyrolysis as means of reducing metal availability in such feed stocks is recently encouraged, but systematic studies are currently lacking. The aim of this study was to assess the impact of pyrolysis temperature on the availability of Cu and Zn by chemical extraction, to determine the speciation of Cu and Zn by synchrotron-based X-ray spectroscopy, and finally to investigate the phase distribution of metal species in the carbonaceous materials by combining acid–base extractions and absorption spectroscopy data. The results showed that both Cu and Zn in the swine manure were mainly bound to organic functional groups. Cu (II) reduction and Cu (I)–S complexes were observed during the pyrolysis process. Zn species resembling ZnAc₂ was still dominant, being 60.8–69.2%, and ZnS increased by 6.6–21.8% in the carbonaceous materials. The distribution of Cu and Zn in the mineral, carbonized and non-carbonized organic phases varied greatly with the pyrolysis temperature. The higher the temperature, the more the metals existed in the mineral phase and carbonized organic phase. The decrease of EDTA extractable Cu and Zn with pyrolysis temperature was due to the increase of metals in the carbonized organic phase and mineral phase. It is suggested that pyrolysis at the relatively higher temperature is a better choice for metal-containing manure according to the metal speciation, solubility and availability.     

石化综合污水处理厂出水溶解性微生物产物的特性

溶解性微生物产物(soluble microbial products,SMP)是生化系统出水残留COD的主要组成部分,通过采用分子量截留超滤分离、有机物树脂分离等方法对某石化综合污水处理厂出水SMP的分子量分布、亲水特性进行了分析研究.结果表明,水样中的SMP占出水残留COD的85%左右。SMP中主要成分是蛋白质,出水中小于1 kDa的有机物是SMP中的主要物质。树脂分离实验表明,亲水性有机物和疏水酸性有机物分别约占出水SMP的50%和20%,是需要进一步处理削减的主要物质类别。     

城市污水厂污泥中重金属去除及其土地利用的研究现状

污泥中富含磷、氮和钾等农作物需要的营养物质,但碍于污泥中残留的重金属离子而难以使用.文章介绍了污泥中重金属的存在形式及作用机理,综述了几种能有效去除重金属的方法(吸附法、淋滤法和化学法),分析了各种方法的优缺点、影响因素、处理效果、适用范围及处理后土地利用的现状,以期处理后的污泥能够作为农用土地,减轻剩余污泥二次污染危...