生化-调碱后垃圾渗滤液的Fenton深度处理效果

针对上海老港垃圾填埋场经过厌氧-曝气塘处理后的渗滤液难进一步处理的问题,对其采用厌氧滤池-好氧接触法、氧化钙2种方式预处理,在此预处理基础上,考察了Fenton法深度处理的效果,探讨了H2O2/Fe2+投加比、初始pH、H2O2投加量、反应时间和Fenton试剂投加方式对渗滤液COD去除效果的影响。研究发现:经过生物预处理后,渗滤液的COD和TP分别降低了24%和25%;氧化钙调碱可以进一步使COD和TP去除率分别达到42%和96%;后续Fenton深度氧化的最佳条件为:初始pH为2,H2O2投加量为2.4 g/L,H2O2/Fe2+摩尔比为5∶1,Fenton试剂一次投加,反应时间为2 h。在此条件下,渗滤液的COD从1 340 mg/L降到198 mg/L,总COD去除率达到85%。     

中国排污权交易的法制建设探讨——以浙江省为例

分析了浙江省排污权交易试点工作中存在的问题,探讨了美国、欧盟等国家和地区的排污权交易法制建设对中国的启示,对国家、地方2个层面进行了排污权交易法制建设的构想。最后,对浙江省排污权交易的法制建设进行了具体设计,并对排污权交易的法制建设提出了可操作性建议。     

全氟化合物污染现状及风险评估的研究进展

全氟化合物(polyfluorinated compounds,PFCs)是近年来受到广泛关注的一类新型持久性有机污染物。PFCs因具有优良的化学稳定性、耐热性以及高表面活性,而被广泛应用于生活消费和工业生产等领域。PFCs具有难降解、生物富集和长距离迁移等特点,已在大气、土壤和水体等环境介质及生物体中检出。在生态环境中,PFCs能够通过食物链不断传递放大,其具有的多种毒性效应已对生态系统和人类造成了一定的威胁。本文主要综述了PFCs在各类环境介质的污染现状、生物的毒性效应、人类摄入健康风险评估以及PFCs的降解研究,以期为未来PFCs的研究提供参考。     

An analytical solution to contaminant diffusion in semi-infinite clayey soils with piecewise linear adsorption

The adsorption of contaminants onto soil particles typically is nonlinear if the contaminant concentration is sufficiently high. A simplified piecewise linear adsorption isotherm consistent with experimental results is proposed as an approximation for nonlinear adsorption behavior. This approximation allows for the use of analytical solution to model solute diffusion of contaminants that exhibit nonlinear adsorption. A moving boundary is introduced to represent significant changes in the retardation factor of clay with an increase in solute concentration. The proposed analytical solutions were validated using experimental data presented in the literature. There is negligible difference between the results obtained by the proposed analytical solution and those obtained by the linear model when C_m/C₀ reached 0.5. The results also show that the model based on linear adsorption using the initial secant of the Freundlich isotherm leads to significantly lower estimated breakthrough time for the contaminant of interest than that obtained using the proposed model. The earlier breakthrough is due to an under-estimation of the amount of adsorption. The proposed method is relatively simple to apply and can be used for evaluating experimental results and verifying more complex numerical models.     

Assessing the feasibility of wastewater recycling and treatment efficiency of wastewater treatment units

Wastewater reuse can significantly reduce environmental pollution and save the water sources. The study selected Cheng-Ching Lake water treatment plant in southern Taiwan to discuss the feasibility of wastewater recycling and treatment efficiency of wastewater treatment units. The treatment units of this plant include wastewater basin, sedimentation basin, sludge thickener and sludge dewatering facility. In this study, the treatment efficiency of SS and turbidity were 48.35–99.68% and 24.15–99.36%, respectively, showing the significant removal efficiency of the wastewater process. However, the removal efficiencies of NH₃–N, total organic carbon (TOC) and chemical oxygen demand (COD) are limited by wastewater treatment processes. Because NH₃–N, TOC and COD of the mixing supernatant and raw water are regulated raw water quality standards, supernatant reuse is feasible and workable during wastewater processes at this plant. Overall, analytical results indicated that supernatant reuse is feasible.     

食物粒径与混合方式对多溴联苯醚生物有效性的影响

多溴联苯醚(PBDEs)是一类典型的持久性有机污染物(POPs),口服摄入是其主要人体暴露途径。口服生物有效性是污染物健康风险评估中的关键因子。论文采用体外方法模拟食物在人体肠道中的消化过程,研究了食物粒径大小以及食物污染与混合方式对PBDEs生物有效性的影响。在150、150~212、212~250和250μm四个粒径范围的胡萝卜中,PBDEs同系物的平均生物有效性分别为48.8%±3.8%、45.2%±5.0%、38.6%±9.3%和37.3%±3.7%。测得菠菜和鲈鱼采用4种混合方式BY1、BY2、BY3和BY4中PBDEs同系物的平均生物有效性分别为17.1%±1.3%、48.3%±3.5%、36.4%±4.9%和44.4%±2.0%,比单纯菠菜(2.6%±0.2%)和鲈鱼(36.3%±4.3%)中的生物有效性高。结果表明,PBDEs的生物有效性随着胡萝卜粒径的增大而减小;不同污染方式再混合食品,比单一食品被污染时,PBDEs的生物有效性更高。     

Development of a novel solid-phase extraction element for the detection of nonylphenol in the surface water of Hangzhou

Nonylphenol (NP) is a representative environmental endocrine-disrupting chemical and persistent toxic pollutant. Previous studies have shown that the average concentration of NP in environmental waters was approximately tens to hundreds of ng L(-1) and it could even reach up to tens of μg L(-1). A simple, fast and accurate method employing a novel solid-phase extraction element named "Magic Chemisorber" (MC) followed by high-performance liquid chromatography (HPLC) using a fluorescence detector (FLD) was used for detecting NP. The most important parameters that affect the extraction process, including extraction time, desorption time, desorption solvent and repeatability, were optimized. The MC-HPLC method showed good linearity with concentrations of NP from 10 to 200 μg L(-1), a correlation coefficient of 0.9995 and the limit of detection (LOD) and limit of quantification (LOQ) of this method was 0.44 and 1.47 μg L(-1), respectively. Compared to commercial polydimethylsiloxane (PDMS) glass fiber, MC had both higher capacity and recovery and it could be used repeatedly. Using the MC-HPLC method we found that the concentration of NP in river water from Hangzhou city ranged from 8.54 ± 1.23 μg L(-1) (Qiantang River) to 65.77 ± 3.69 μg L(-1) (Tiesha River), which was similar to that of international regions heavily polluted with NP and higher than that of Bohai Bay, the Yellow River and the Pearl River Delta in China. This level of NP pollution is possibly related to the rapid development of the textile, printing and paper industries of Zhejiang province.     

两段式蚯蚓强化快速渗滤系统的试验研究

通过分析不同水力负荷下两段式蚯蚓强化快速渗滤系统进出水水质以及堵塞问题,研究水力负荷对两段式蚯蚓强化快速渗滤系统污水处理效果的影响.试验结果表明,陶粒柱中,当水力负荷从2 m3/(m2·d)提高到6 m2/(m2·d)时,COD去除率下降.水力负荷对出水污泥SS的影响不显著,但出水污泥VSS/SS却与水力负荷呈极显著正相关;煤渣桂中,水力负荷提高对有机物去除效果有一定的影响,但影响程度较小.随水力负荷的提高,煤渣柱出水NH4 -N浓度逐渐升高.其平均去除率分别为74.51%,58.21%、45.53%,下降趋势明显;由于陶粒柱中蚯蚓的作用和陶粒柱的预处理作用,在提高水力负荷的情况下,陶粒柱和煤渣柱均未发生堵塞问题,装置运行稳定.     

旅游景区标识系统的个性化实现路径研究——以三峡车溪民俗旅游区为例

旅游景区标识系统在展示景区形象、引导和管理旅游者、提升旅游者体验等方面具有重要作用,规范化与个性化是其设计的基本要求.在阐明景区标识系统的个性化内涵基础上,探讨了基于文化符号的个性化实现路径;以三峡车溪民俗旅游区为例,对其标识系统进行了个性化改进设计,以期为景区标识系统个性化建设提供理论指导和经验借鉴.     

生活垃圾可持续化填埋

通过对中国填埋场现状分析,提出了"可持续填理"的概念.认为生活垃圾填埋场将从单纯的最终处置场所演变为填埋与中转相结合的场所.填埋场的可持续发展也将从两方面得到体现:一为垃圾降解过程及其副产品处理中以能量形式得到利用,另一方面为稳定化后的垃圾及填埋场本身空间得到再一次的利用.