生物滴滤池法处理废气动力学模式研究

基于物料平衡和微生物降解废水中污染物的动力学模式,以丙酮、甲苯为处理对象提出了生物滴滤池处理废气的模式。当入口浓度C_(in)较低,小于临界浓度C_(crit),时,C=C_(in)EXP((-B/V_g)·H);当人口浓度C_(in)较高,大于临界浓度C_(crit)时,C=C_(in)-(K_0X/V_g)·H。研究表明,实验结果与模式计算结果吻合较好。     

矿区湖泊微型浮游生物对重金属的富集研究——以湖北大冶湖和磁湖为例

以湖北大冶湖和磁湖为研究对象,分析了矿区湖泊表层水和微型浮游生物中Cu、Pb、Cd、Zn、Cr、Fe 6种重金属的含量,并对矿区湖泊表层水重金属污染和微型浮游生物对重金属的富集能力进行了评价.结果表明:大冶湖表层水中重金属Cu、Pb、Cd、Zn、Cr和Fe的平均浓度分别为0.009 1 mg/L、0.013 4 mg/L、0.009 2 mg/L、0.043 4 mg/L、0.057 8 mg/L、0.338 2 mg/L,磁湖表层水中重金属Cu、Pb、Cd、Zn、Cr和Fe的平均浓度分别为0.004 3 mg/L、0.012 7 mg/L、0.001 1 mg/L、0.389 2 mg/L、0.063 4 mg/L、0.7110mg/L;大冶湖微型浮游生物中重金属Cu、Pb、Cd、Zn、Cr和Fe的平均浓度分别为278.6 mg/kg干重、695.6 mg/kg干重、23.1 mg/kg干重、578.0mg/kg干重、323.5 mg/kg干重、142 14 mg/kg干重,磁湖微型浮游生物中重金属Cu、Pb、Cd、Zn、Cr和Fe的平均浓度分别为316.1 mg/kg干重、361.4 mg/kg干重、2.06 mg/kg干重、1 004.5 mg/kg干重、313.3 mg/kg干重、18 366 mg/kg干重;大冶湖和磁湖微型浮游生物中的重金属含量远高于表层水中的重金属含量,甚至高于表层沉积物中的重金属含量;矿区湖泊微型浮游生物对重金属的富集系数在1 800～82 600之间,其中微型浮游生物对Cd、Zn、Cr的富集系数较小,对Cu、Pb、Fe的富集系数较大.     

pH对铜在黄土中吸持及其形态的影响

用黄土为吸持剂,以石英砂作对照,研究了pH对铜的吸持及形态的影响,并用MINTEQA2模型对铜离子的沉淀形态进行了理论计算.结果表明:无论吸持剂是石英砂还是黄土,随着pH的升高,吸持曲线都分为3区:低pH微吸持区、中pH吸持增长区和高pH强吸持区.含沙量一定,随着铜液初始浓度的增加,吸持量、可交换态含量和碳酸盐结合态含量均增加;铜液初始浓度一定,随着含沙量的增加,吸持量、可交换态含量和碳酸盐结合态含量均减少.MINTEQA2模型计算结果表明,对于不同的吸持剂,铜离子发生沉淀的比例及沉淀的物质组成是不同的;以黄土为吸持剂时,中pH范围内随着含沙量的增加铜离子沉淀的比例减少.     

CALPUFF模型在大气环境容量测算中的应用研究

本研究利用CALPUFF空气质量扩散模式模拟了凉山州2007年气象场和s02浓度场,通过现状监测结果与模拟结果的比较评述了模型的适用性;并根据西昌市现状污染源和虚拟污染源情况,通过CALPUFF模拟建立大气污染物传递矩阵,结合线性优化模型测算了西昌市大气环境容量。     

臭氧+曝气生物滤池深度处理工艺试验研究

针对某污水厂出水不达标的情况,本研究采用臭氧(O3)和曝气生物滤池(BAF)组合工艺对其进行深度处理.结果表明,当采用两级臭氧+曝气生物滤池工艺时,出水COD在31～46 mg/L,色度在13～29倍,均达到一级A排放标准.在最佳运行条件下,臭氧氧化使相对分子质量大于50 000的有机物含量减少10％,小于1 000的有机物含量增加14％.曝气生物滤池工艺使相对分子质量小于1 000的有机物含量降低了24％.     

沸石改良土壤的研究进展

沸石因其独特的晶体结构具有较强的离子交换能力和吸附能力,作为良好的土壤改良剂逐步引起了人们的广泛重视。简要综述了沸石对土壤的理化性质、重金属、植物、微生物和酶的影响及其研究进展。     

5种沉水植物对重金属富集能力的对比研究

为了探求不同的沉水植物对水体中重金属吸收富集能力的差异,采用原子吸收光谱法,对淮河支流东风渠水体及水体中常见的5种沉水植物:菹草、黑藻、龙须眼子菜、穗花狐尾藻及小茨藻进行了铅(Pb)、镉(Cd)、锌(Zn)、铜(Cu)含量分析。结果表明:5种沉水植物样品中重金属含量远远高于水体重金属背景值,对重金属Cu、Pb、Cd、Zn的富集系数为58~1 515,对Zn富集最强,最大富集量达到242.42 mg/kg,富集系数为1 515。不同的沉水植物对重金属的吸收富集优势存在明显差异,利用沉水植物来修复水体重金属污染时,须依据不同的污染元素来选择合适的沉水植物。     

Fractionation of heavy metals in shallow marine sediments from Jinzhou Bay, China

This work investigated the distribution and speciation of Cd, Cu, Pb, Fe and Mn in the shallow sediments of Jinzhou Bay, Northeast China, which has been heavily contaminated by nonferrous smelting activities. The concentrations of Cd, Cu and Pb in sediments were found to be 100, 13 and 7 times, respectively, being higher than the national guideline (GB 18668-2002). Sequential extraction test showed that 39%-61% of Cd were exchangeable fractions, indicating that Cd in the sediments posed a high risk to local...     

Adsorption of mixed cationic-nonionic surfactant and its effect on bentonite structure

The adsorption of cationic-nonionic mixed surfactant onto bentonite and its effect on bentonite structure were investigated. The objective was to improve the understanding of surfactant behavior on clay mineral for its possible use in remediation technologies of soil and groundwater contaminated by toxic organic compounds. The cationic surfactant used was hexadecylpyridinium bromide (HDPB), and the nonionic surfactant was Triton X-100 (TX100). Adsorption of TX100 was enhanced significantly by the addition of HDPB, but this enhancement decreased with an increase in the fraction of the cationic surfactant. Part of HDPB was replaced by TX100 which decreased the adsorption of HDPB. However, the total adsorbed amount of the mixed surfactant was still increased substantially, indicating the synergistic effect between the cationic and nonionic surfactants. The surfactant-modified bentonite was characterized by Brunauer-Emmett-Teller specific surface area measurement, Fourier transform infrared spectroscopy, and thermogravimetric-derivative thermogravimetric/differential thermal analyses. Surfactant intercalation was found to decrease the bentonite specific surface area, pore volume, and surface roughness and irregularities, as calculated by nitrogen adsorption-desorption isotherms. The co-adsorption of the cationic and nonionic surfactants increased the ordering conformation of the adsorbed surfactants on bentonite, but decreased the thermal stability of the organobentonite system.     

Fabrication and photoelectrocatalytic properties of nanocrystalline monoclinic BiVO4 thin-film electrode

Monoclinic bismuth vanadate(BiVO4) thin film was fabricated on indium-tin oxide glass from an amorphous heteronuclear complex via dip-coating.After annealation at 400,500,and 600°C,the thin films were characterized by X-ray diffraction,field emission scanning electron microscopy,X-ray photoelectron spectroscopy,and UV-Vis spectrophotometry.The BiVO4 particles on the ITO glass surface had a monoclinic structure.The UV-Visible diffuse reflection spectra showed the BiVO4 thin film had photoabsorption propertie...