污泥堆肥项目中除臭技术的选择与设计

介绍了我国污泥堆肥(生物干化)项目臭气治理现状,指出除臭问题是制约污泥堆肥技术推广应用的关键。对比各种除臭技术,分析了污泥堆肥臭气成分和除臭机理,得出结论:化学生物组合除臭工艺与植物液除臭工艺相结合是适合污泥堆肥项目的选择。最后介绍了除臭系统设计选型的主要参数,指出在污泥处理工艺设计中考虑除臭系统可节省投资和运行成本。     

Mobility of radium and trace metals in sediments of the Winterbeek: Application of sequential extraction and DGT techniques

For several decades, phosphate ores containing ²²⁶Ra as well as several trace metals have been processed in Belgium to produce calcium phosphate for use in cattle food. The waste water is discharged in two small rivers, the Laak and the Winterbeek.In this study, the levels of ²²⁶Ra and trace metals in surface water and sediments of the Winterbeek were investigated and the mobility of these compounds was assessed using DGT (Diffusive Gradient in Thin Films) and sequential extraction techniques.The concentrations of ²²⁶Ra and trace metals in water and sediment indicate a decreasing trend in inputs to the Winterbeek.The mobility of ²²⁶Ra, assessed by DGT, is related to the reductive mobilization of Fe. The sequential extraction technique shows that at some stations an important fraction of ²²⁶Ra is found to labile sediment phases.Diffusive ²²⁶Ra sediment fluxes, are however, relatively small and have only a minor contribution to the water column concentration of ²²⁶Ra.     

电磁阀贮存寿命加速试验技术研究

首先陈述了贮存寿命加速试验的基本原理,介绍电磁阀的结构组成,分析了失效模式和失效机理后,采取恒定应力加速试验方法,然后运用极大似然估计和最小二乘法对数据进行处理,最后得出其贮存寿命等结论。     

聚环氧琥珀酸对锰渣中砷的萃取

以锰渣为材料,用聚环氧琥珀酸(PESA)作为萃取剂,研究PESA在不同pH、萃取剂浓度、土液比下对砷(As)的萃取效果。实验结果表明,与丙烯酸/马来酸酐共聚物(MA/AA)相比较,PESA对锰渣中As有优良的萃取效果。在萃取体系条件为pH=1、萃取剂浓度50 mg/mL、土液比1∶200、搅拌60 min并浸泡过夜时,PESA对砷的萃取率可达78.3%。实验还发现,PESA对三价砷和五价砷均有螯合萃取作用,对砷的萃取无价态的选择性。     

M3法测定土壤有效态Cd、Cr、Pb和Ni

通过M3法对耕地土壤重金属的联合测定,为土壤重金属污染监测应用提供快速联合测定的方法。用M3法测定北方耕地土壤的有效Cd、Cr、Pb和Ni,通过对M3法与其他方法进行有效重金属测定值差异性及其相关性比较,与全量的浸出率分析等探讨M3法对耕地土壤有效重金属测定的特征。结果表明,M3法在《土壤环境质量标准》(GB 15618—1995)的土壤重金属含量范围内可以测定土壤有效态重金属Cd、Cr、Pb和Ni,且呈线性极显著相关。M3法与其他方法有效Cd、Cr、Pb和Ni有较好的相关性,与DTPA法呈极显著相关;与NaNO₃法除有效Pb外,呈极显著和显著相关;与HCl法除褐土和潮土的有效Pb外,也呈极显著和显著相关。M3法的有效态Cd、Cr、Pb和Ni的测定值均为最大。M3法对4种耕地土壤有效Cd、Cr、Pb和Ni的浸出率,因土壤类型不同,有效重金属含量所占比率不同,但利用M3法测定的有效态Cd、Cr、Pb和Ni的浸出率最大。     

Evaluation of C18 solid‐phase extraction cartridges for the isolation of select pesticides and metabolites

Abstract

Nine different C₁₈ solid‐phase extraction (SPE) cartridges were evaluated for their efficiency at extracting nine pesticides and two s‐triazine metabolites from spiked deionized water samples. The SPE cartridges were found to contain nitrogen (N) and/or phosphorus (P) contaminants and varied in their extraction efficiency for certain pesticides and metabolites. Four of the nine SPE cartridges gave acceptable (70 to 120%) pesticide and metabolite recovery percentages, while five cartridges had marginal (50 to 70%) to poor (< 50%) recoveries. Statistical analyses showed that the poor to marginal recoveries found for three compounds could not be explained by considering several indigenous chemical and physical traits of the cartridge. It is suggested that proper SPE cartridge selection for pesticide recovery should be evaluated using several different cartridges.     

六自由度气锤振动技术与电磁斜面振动技术比较

六自由度气锤振动与电磁斜面振动是两种模拟产品三轴振动的振动技术。由于两种振动技术的机理不同，其对样品的振动影响也会有区别。本文研究讨论两种不同振动技术的不同特点，以及对不同产品的振动效果别，我们可以根据样品特点和测试需求，选择更合适的震动技术。     

一种活性污泥总DNA提取方法的优化

对3种活性污泥DNA提取方法———传统蛋白酶K-SDS-氯仿异戊醇法(CPSCI法)、液氮研磨法和脱腐处理法进行了对比,并针对CPSCI法从污泥量、保温时间、裂解方式及沉淀时间等4个方面进行了优化。结果表明,优化的蛋白酶K-氯仿-异戊醇法(OPSCI法)采用污泥量0.10 g、37℃静置10 min,加SDS常温旋涡振荡及异丙醇直接离心等条件可获得长度在23.1 kb左右的DNA,OD260nm/OD280nm为1.86,稀释10倍后即可进行16S rDNA PCR。该方法重复性好,提取得率高,纯度好,操作简便,为常规实验室开展活性污泥微生物多样性研究提供了帮助。     

Genotoxicity of sediment extracts of the Berre lagoon (France)

To evaluate the genotoxic risk that contaminated sediment could constitute for benthic organisms, three contaminated (VA, VC and VN) and one uncontaminated (RN) sediment samples were collected in the Berre lagoon (France). Potentially bioavailable contaminants in sediments were obtained using sediment extraction with synthetic seawater adjusted to pH 4 or pH 6, simulating the range of pH prevailing in the digestive tract of benthic organisms. The genotoxic activities of these extracts were evaluated by three short-term bioassays: the Salmonella mutagenicity test using the Salmonella typhimurium strain TA102, the alkaline comet assay and the micronucleus assay on the Chinese Hamster Ovary cells CHO-K1. Results of the Salmonella mutagenicity assay detected a mutagenic response for RN extract at pH 6, and for VA extract at pH 4. Results of the comet and micronucleus assays detected low genotoxic/clastogenic activities for VA and VC extracts at pH 6 and higher activities for RN, VA and VC extracts at pH 4. To identify if metals (Al, Fe, Mn, As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn) were involved in these genotoxic activities, their concentrations were determined in the extracts, and their speciation was assessed by thermodynamic calculations. Results showed that extracts from sites VA, VC and VN generally presented the highest trace metal contents for both extractants, while the site RN presented lower trace metal contents but the highest Fe and Mn contents. Thermodynamic calculations indicated that Fe, Mn, As and in a lower extend Co, Ni and Zn were mainly present under free forms in extracts, and were consequently, more likely able to induce a genotoxic effect. Results globally showed no correspondence between free metal contents and genotoxic activities. They suggested that these positive results could be due to uncharacterized compounds, acting as direct genotoxic agents or enhancing the genotoxic properties of analyzed metals.     

江苏盐城滩涂土壤中多环芳烃的测定

文中采用江苏盐城滩涂响水到滨海一带的滩涂土壤样品,利用索氏提取法提取、硅胶柱净化、高效液相色谱法分离检测土壤样品中的多环芳烃(PAHs),并用优化洗脱程序对滩涂土壤中PAHs的含量进行了测定。结果表明:11个滩涂土壤样品中检出萘、苊烯、菲、蒽、荧蒽、芘六种PAHs,其含量较低,说明该段滩涂土壤尚未受到多环芳烃的污染。