黑臭底泥土著微生物促生对磷的影响

土著微生物促生是一项低成本高效率的河湖黑臭底泥原位修复技术,然而向底泥中投加药剂可能会影响上覆水水质。为探讨该技术对水环境的不利影响,实验研究了城市湖泊黑臭底泥修复过程中上覆水中磷浓度和底泥中磷含量及形态的变化。结果表明,在投药深度为泥面以下15 cm,微生物营养剂（BE）和生物解毒剂（MT）的投加量分别低于60mL/m3和70 mL/m3的条件下,上覆水总磷（TP）浓度低于地表水环境质量Ⅲ类（湖库类）标准值。投加微生物促生剂（BE和MT）导致上覆水磷含量升高,并促进了上覆水中藻类的增长。复配投加硝酸钙能减少上覆水中磷含量及藻类生物量,从而抑制微生物促生剂对上覆水磷浓度的影响。另外,投加微生物促生剂及硝酸钙到底泥中后,底泥磷含量以及磷形态组成的变化均不明显。     

改性污泥替代垃圾填埋场覆土的研究

以市政污泥为研究对象，采用固化剂对污泥进行改性，通过分析不同固化剂添加比例下固化产物的抗压强度和渗透系数，比较不同养护时间下污泥固化产物浸出液的COD、氨氮和重金属性质，探讨市政污泥固化产物作为垃圾填埋场覆土可行性。实验结果表明：固化剂添加比例为30％的固化产物抗压强度高于50kPa，其渗透系数达到10^-7cm／s数量级，基本满足覆土材料的标准要求。污泥固化产物重金属的最大浸出量远远低于《污水综合排放标准》（GB8978-88）中一级排放标准。随养护时间延长，固化产物浸出液COD和氨氮浸出浓度亦呈下降趋势，重金属Pb、Cd浸出量明显减少，浸出比例小于1％。养护有利于降低固化产物的浸出污染程度，30％的污泥固化产物养护3d后可作为垃圾填埋场日覆盖材料。     

Using variances in hydrocarbon concentration and carbon stable isotope to determine the important influence of irrigated water on petroleum accumulation in surface soil

Hunpu is a wastewater-irrigated area southwest of Shenyang. To evaluate petroleum contamination and identify its sources at the area, the aliphatic hydrocarbons and compound-specific carbon stable isotopes of n-alkanes in the soil, irrigation water, and atmospheric deposition were analyzed. The analyses of hydrocarbon concentrations and geochemical characteristics reveal that the water is moderately contaminated by degraded heavy oil. According to the isotope analysis, inputs of modern C3 plants and degraded petroleum are present in the water, air, and soil. The similarities and dissimilarities among the water, air, and soil samples were determined by concentration, isotope, and multivariate statistical analyses. Hydrocarbons from various sources, as well as the water/atmospheric deposition samples, are more effectively differentiated through principal component analysis of carbon stable isotope ratios (δ¹³C) relative to hydrocarbon concentrations. Redundancy analysis indicates that 57.1 % of the variance in the δ¹³C of the soil can be explained by the δ¹³C of both the water and air, and 35.5 % of the variance in the hydrocarbon concentrations of the soil can be explained by hydrocarbon concentrations of both the water and the air. The δ¹³C in the atmospheric deposition accounts for 28.2 % of the δ¹³C variance in the soil, which is considerably higher than the variance in hydrocarbon concentrations of the soil explained by hydrocarbon concentrations of the atmospheric deposition (7.7 %). In contrast to δ¹³C analysis, the analysis of hydrocarbon concentrations underestimates the effect of petroleum contamination in the irrigated water and air on the surface soil. Overall, the irrigated water exerts a larger effect on the surface soil than does the atmospheric deposition.     

Reducing volatilization of heavy metals in phosphate-pretreated municipal solid waste incineration fly ash by forming pyromorphite-like minerals

This research investigated the feasibility of reducing volatilization of heavy metals (lead, zinc and cadmium) in municipal solid waste incineration (MSWI) fly ash by forming pyromorphite-like minerals via phosphate pre-treatment. To evaluate the evaporation characteristics of three heavy metals from phosphate-pretreated MSWI fly ash, volatilization tests have been performed by means of a dedicated apparatus in the 100-1000 °C range. The toxicity characteristic leaching procedure (TCLP) test and BCR sequential extraction procedure were applied to assess phosphate stabilization process. The results showed that the volatilization behavior in phosphate-pretreated MSWI fly ash could be reduced effectively. Pyromorphite-like minerals formed in phosphate-pretreated MSWI fly ash were mainly responsible for the volatilization reduction of heavy metals in MSWI fly ash at higher temperature, due to their chemical fixation and thermal stabilization for heavy metals. The stabilization effects were encouraging for the potential reuse of MSWI fly ash.     

生物法生成单质硫过程中氧化还原电位的研究

采用升流式好氧反应器,接种实验室自行培养的排硫硫杆菌,进水硫化物质量浓度为343～356 mg/L,在不同容积负荷下,研究不同氧化还原电位(ORP)对硫化物生物转化的影响.结果表明,ORP为(-260±10)mV时,硫化物去除率均达95%以上;随着ORP的降低,硫化物去除率和硫酸根生成率均呈下降趋势;不同容积负荷下,控制合适的ORP均可得到单质硫的最大生成率.     

微波污泥上清液为燃料的微生物燃料电池内阻分布

实验采用单室无膜悬浮阴极微生物燃料电池（MFC），考察了微波污泥上清液为燃料的MFC（MSMFC）的内阻组成。研究表明，当未投加氯化钠时，MSMFC内阻为486．13Ω。当投加100mmol／L的氯化钠时，内阻迅速下降为207．18Ω。而投加量进一步增加时，内阻变化不明显。当阳极面积从4cm2增加到8cm2时，MSMFC内阻从387．34Ω迅速下降到293．96n。而当阳极面积增加到24cm。时，MSMFC内阻变化不明显。但当阳极面积增加到60cm2时，MSMFC内阻下降了38．4％。当阴极面积从24．87cm2增加到49．74cm2时，MSMFC内阻减少了40．4％（从545．72Ω减少到220．56Q）。MSMFC中阳极内阻占主要部分，其次为阴极内阻，电解液电阻最小。随着阴阳极面积比的增加，阴阳极电阻比例减少，说明控制阴阳极面积比可以调整系统内阻的分配。     

阴离子对地下水中氯苯微电解的影响

在模拟氯苯污染的地下水中分别添加Cl-,SO4 -,NO3-,CO32-,HCO3-等阴离子,考察了各种阴离子对氯苯去除率的影响.实验结果表明:SO4 -质量浓度对氯苯去除率影响不明显；HCO3-质量浓度为200～ 400 mg/L、反应5h时,氯苯去除率与未加HCO3-的空白试样的氯苯去除率接近；随Cl-质量浓度增加...     

从“人肉搜索”看网络媒介灾害信息的非主流传播

汶川地震“人肉搜索”事件集中代表了网络媒介灾害信息的非主流传播，成为灾后社会舆论的重要组成部分。本文从汶川地震“人肉搜索”事件入手，结合大量实例，分析了网络媒介灾害信息非主流传播的特点、功能及存在的问题，并提出了有效解决的方法。     

Trapping and decomposing of color compounds from recycled water by TiO2 coated activated carbon

Five types of commercially available activated carbons (ACs) were coated with TiO₂ nanoparticles prepared using a sol–gel method. Color and trace organics remaining in the actual treated effluent were adsorbed by TiO₂ coated ACs. The absorbed organic compounds were then decomposed using a photocatalytic process, and the ACs were regenerated for reuse. The efficiency of the process was assessed by the characterization of true color and A₂₅₄ (the organics absorption at the wavelength of 254 nm) at the beginning and the end of the experiment. The effects of UV light source, UV irradiation time, hydrogen peroxide and ultrasound on the efficiency of photocatalytic regeneration were also investigated. Significant differences in the efficiency were observed between uncoated ACs and TiO₂ coated samples. Among the 5 types of ACs tested, AC-3, AC-4 and their coated ones achieved better efficiency in color and A₂₅₄ removal, with around 90% or more color and A₂₅₄ being removed within 1 h of treatment. The data obtained in this study also demonstrated that the photocatalytic process was effective for decomposing the adsorbed compounds and regenerating the spent TiO₂/AC-3. Finally, it was found that this regeneration process could be greatly enhanced with the assistance of H₂O₂ and ultrasound by reducing the required regeneration time.     

MAP法处理饲料级磷酸氢钙母液的研究

运用 MAP(磷酸铵镁)法处理高浓度饲料级磷酸氢钙母液,研究了处理的最优反应条件并分析了最优条件下所得产物成分.结果表明,母液处理的最优反应条件为pH=9.5,n(NH4 ):n(PO43-)=1:1,反应时间 10 min,反应温度40℃以下.该条件下,当温度为40℃时,PO43-、Mg2 和Ca2 的去除率分别达到 98.46%、92.54%和98.48%,残留浓度分别为 15.91、70.25 和2.94 me/L.生成的沉淀产物中 P2O5、NH4 -N、CaO 和MgO 所占重量百分比分别为29.08%、6.07%、2.83%和 15.91%,所含 MAP 可作为肥料回收利用.