Effects of sulfur dioxide and nitric oxide on mercury oxidation and reduction under homogeneous conditions

This paper is particularly related to elemental mercury (Hg0) oxidation and divalent mercury (Hg2+) reduction under simulated flue gas conditions in the presence of nitric oxide (NO) and sulfur dioxide (SO2). As a powerful oxidant and chlorinating reagent, Cl2 has the potential for Hg oxidation. However, the detailed mechanism for the interactions, especially among chlorine (Cl)-containing species, SO2, NO, as well as H2O, remains ambiguous. Research described in this paper therefore focused on the impacts of SO2 and NO on Hg0 oxidation and Hg2+ reduction with the intent of unraveling unrecognized interactions among Cl species, SO2, and NO most importantly in the presence of H2O. The experimental results demonstrated that SO2 and NO had pronounced inhibitory effects on Hg0 oxidation at high temperatures when H2O was also present in the gas blend. Such a demonstration was further confirmed by the reduction of Hg2+ back into its elemental form. Data revealed that SO2 and NO were capable of promoting homogeneous reduction of Hg2+ to Hg0 with H2O being present. However, the above inhibition or promotion disappeared under homogeneous conditions when H2O was removed from the gas blend.     

低温降解六六六优势菌种的选育研究

通过实验,筛选出低温条件(≤10℃)下降解六六六的优势菌株--1号菌株,同时利用正交实验测得该菌株的最佳降解条件为:pH=5.5、接菌量2 g/L、NH4Cl 0.8 g/L、KH2PO4 0.6 g/L、MgSO4 0.2 g/L.在此条件下,经30 d驯化后的菌株对六六六的降解率由原来的54.71%提高到62.58%     

中国淘汰滴滴涕的环境影响分析

目前中国仍在生产滴滴涕(DDT),并以其为原料生产三氯杀螨醇作为杀虫剂使用.为评价淘汰DDT对于中国生态环境的影响,采用情景分析的方法,估算了在采取不同的淘汰策略下土壤中DDT残留浓度的变化,以此来评价淘汰DDT的环境影响.与基线情景相比,三种控制情景下DDT的累积生产量都有不同程度的减少,相应土壤中的残留浓度也有不同的下降,且淘汰的速度越快土壤中DDT浓度下降的幅度越大.     

利用水泥处理垃圾渗滤液生物处理出水的研究

利用水泥的表面吸附和水化反应性质处理垃圾渗滤液生物处理出水可以取得很好的效果,COD的去除率可达69.5%.处理效果与水灰比、反应时间密切相关,低水灰比和较长反应时间对COD的去除更为有利.对处理前后水样的COD和TOC分析表明,水泥对非TOC贡献的COD有很强的去除效果.     

生活垃圾填埋场封场后种植植物中重金属迁移研究

在上海老港生活垃圾填埋场填埋单元封场的覆盖土中掺混了矿化垃圾种植植物,分析Cd、Pb、Cu、Zn 4种重金属在土壤和植物中的迁移变化,研究表明:(1)覆盖土土质从一般耕作土变成肥沃土壤;覆盖土和种植混合土重金属Cd、Pb、Cu、Zn中Cd、Pb含量相近,但种植土的Cu含量略大于覆盖原土,Zn含量远大于覆盖原土;(2)植物能富集土壤和垃圾中的重金属,木本植物的根部富集重金属的能力强于草本植物,但重金属在草本植物根、茎、叶中的迁移速度大于木本植物;(3)植物根、茎、叶的Cu、Zn含量均远大于未受污染土壤种植植物相应部位的Cu、Zn含量,种植的植物不能供家养动物食用,以免通过食物链作用危及人体安全.     

城市生活污水处理后回用作热电厂循环冷却水的可行性研究

选用适合热电厂特点的水处理剂,利用静态试验,动态模拟试验手段,对城市生活污水回用于热电厂循环冷却水系统中的复配药剂的阻垢缓蚀性能进行了研究.通过试验表明,污水回用是可行的,为城市生活污水回用于热电厂循环冷却水系统工程提供了可靠的参数.     

Fenton试剂法处理甘氨酸废水中COD的研究

通过正交试验的方法用Fenton试剂对甘氨酸生产中的工业废水进行了试验研究,分析了各因素影响程度及各影响因子的作用机理,得出了最佳的操作条件为:H2O2:COD=1.8,[Fe2 ]=40 mmol/L,反应温度40℃,pH值为3,反应时间为80 min,最终的COD去除率为68%左右.     

微波辅助空气氧化水溶液中的PCP

采用活性炭为催化剂,对微波辅助空气氧化水溶液中的五氯酚进行了处理研究.考察了活性炭投加量、微波功率、辐射时间和通气量对溶液中五氯酚的去除率的影响.结果表明,在通气量为0.2 L/min,微波功率800 W和微波辐射60 min时,五氯酚的去除率可达到90%以上;对微波辐射前后的滤液进行紫外扫描和pH分析,可证实五氯酚被降解.     

Ionic liquid-containing semipermeable membrane devices for monitoring the polycyclic aromatic hydrocarbons in water

Ionic liquid-containing semipermeable membrane devices (IL-SPMDs) were developed to monitor the polycyclic aromatic hydrocarbons in water. Uptake kinetics of naphthalene, 1-methylnaphthalene, phenanthrene, pyrene, chrysene by layflat low-density polyethylene tubing (15 cm x 2 cm) filled with 0.5 ml 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid were studied in a laboratory continuous-flow system for the duration of 16 days. The device concentration factors were in the range of 830-7800 for the studied PAHs. The kinetic parameters of IL/water partition coefficients, analytes uptake rate constants and sampling rates were estimated using mathematical models. These parameters were used in the field experiment to estimate the concentrations of the PAHs in Lanzhou section of Yellow River in China, with the result in comparison with that obtained by triolein-SPMD.     

一种高速反硝化颗粒污泥的培养

以葡萄糖为碳源,在USB反应器内接种好氧活性污泥在40 d内培养出良好的反硝化颗粒污泥.颗粒污泥形成经历了2个阶段:起始阶段,接种的好氧活性污泥中非反硝化菌逐渐衰亡演变为"惰性固体",与原有的固体一起,成为反硝化菌附着生长的载体,与此同时,反硝化菌在载体表面渐渐繁殖,形成细颗粒污泥;随后,反硝化菌在细颗粒污泥表面不断增殖,颗粒长大,发育成为成熟的颗粒污泥.成熟的颗粒污泥密实,表面均为杆状菌,且排列紧密,当污泥床容积负荷为19.1 g N/L·d时,去除率高达98.4%(N).