南京某城市污水二级处理系统中酞酸酯类的分布及去除特征

以南京某城市污水厂污水和污泥中的酞酸酯类（PAEs）为研究对象,分别采用固相萃取-气相色谱-质谱联用（SPE—Gc．Ms）和超声提取．气相色谱．质谱联用（USE—GC—Ms）检测其中的优先控制污染物邻苯二甲酸二甲酯（DMP）、邻苯二甲酸二乙酯（DEP）、邻苯二甲酸二丁酯（DBP）和邻苯二甲酸单（2-乙基己基）酯（MEHP）,研究其在厌氧／好氧（A／O）污泥处理过程中的分布特征及降解规律。研究结果表明,各类PAEs在该污水厂的污水和污泥中均有检出,二级处理出水中4种酞酸酯类物质的浓度在0．151—2．419μg／L。污水中4种酞酸酯的分布规律为MEHP〉DBP〉DMP〉DEP,污泥中4种酞酸酯的分布规律为MEHP〉DBP〉DEP〉DMP。该污水厂二级处理工艺对4种PAEs的去除效果较明显,去除效率DBP〉DEP〉DMP〉MEHP．     

发酵类抗生素废水处理工艺及运行效果

介绍了内蒙古某抗生素废水处理厂的处理工艺流程、处理单元类型及其详细设计参数,通过对该污水处理厂半年内运行效果的调研,分析评价该污水处理系统的处理效果及出水指标;该水厂工艺流程对COD、TOC、氨氮、总氮、总磷、BOD和急性毒性的平均去除率分别为96.52%、95.83%、50.24%、55.20%、62.05%、98.52%和99.14%,COD、氨氮、总氮、总磷出水水质分别为477、438、556.7和7.69 mg/L,达到排放到城区下水道要求,园区内所有废水汇集到园区污水处理厂进行集中深度处理达标后排放水体。通过对该水厂工艺的介绍和水质分析,为我国抗生素生产企业面临的废水处理工艺类型选择及工程改造升级提供一定参考。     

宝钢焦化废水处理脱氮研究与实践

针对上海提高新排放标准中总氮(TN)≤35 mg/L的要求,对焦化废水进行了脱氮研究。选取现场缺氧-好氧-好氧(A-O-O)工艺中前两段的A-O生化沉淀池1出水,在SBR内进行反硝化脱氮实验,考察葡萄糖、葡萄糖+乙酸钠、甲醇和甲醇+乙酸钠单一或复合碳源及投加反硝化菌种对脱氮的影响,确定最佳碳源为甲醇+乙酸钠,最佳反硝化水力停留时间为16 h。当反硝化菌液投加浓度为1 mg/L时,SBR出水TN满足达标排放要求。结合实验结果对宝钢焦化废水原有AO-O工艺改造升级为A-O-A-O二段脱氮工艺,并对生化出水实施进一步的物化混凝处理。改造后,工艺长期运行稳定,最终出水完全达到上海市污水综合排放标准(DB 31/199-2009)TN≤35 mg/L的要求,并满足氰化物、氟化物以及COD的排放要求。     

Industrial wastewater pre-treatment for heavy metal reduction by employing a sorbent-assisted ultrafiltration system

This work examined the adoption of a sorbent-assisted ultrafiltration (UF) system for the reduction of Pb(II), Cu(II), Zn(II) and Ni(II) from industrial wastewater. In such a system metals were removed via several processes which included precipitation through the formation of hydroxides, formation of precipitates/complexes among the metal ions and the wastewater compounds, adsorption of metals onto minerals (bentonite, zeolite, vermiculite) and retention of insoluble metal species by the UF membranes. At pH = 6 the metal removal sequence obtained by the UF system was Pb(II) > Cu(II) > Zn(II) > Ni(II) in mg g⁻¹ with significant amount of lead and copper being removed due to chemical precipitation and formation of precipitates/complexes with wastewater compounds. At this pH, zinc and nickel adsorption onto minerals was significant, particularly when bentonite and vermiculite were employed as adsorbents. Metal adsorption onto zeolite and bentonite followed the sequence Zn(II) > Ni(II) > Cu(II) > Pb(II), while for vermiculite the sequence was Ni(II) > Zn(II) > Cu(II) > Pb(II) in mg g⁻¹. The low amount of Pb(II) and Cu(II) adsorbed by minerals was attributed to the low available lead and copper concentration. At pH = 9 the adoption of UF could effectively reduce heavy metals to very low levels. The same was observed at pH = 8, provided that minerals were added. The prevailing metal removal process was the formation of precipitates/complexes with wastewater compounds.     

Zero-valent iron nanoparticles in treatment of acid mine water from in situ uranium leaching

Acid mine water from in situ chemical leaching of uranium (Straz pod Ralskem, Czech Republic) was treated in laboratory scale experiments by zero-valent iron nanoparticles (nZVI). For the first time, nZVI were applied for the treatment of the real acid water system containing the miscellaneous mixture of pollutants, where the various removal mechanisms occur simultaneously. Toxicity of the treated saline acid water is caused by major contaminants represented by aluminum and sulphates in a high concentration, as well as by microcontaminants like As, Be, Cd, Cr, Cu, Ni, U, V, and Zn. Laboratory batch experiments proved a significant decrease in concentrations of all the monitored pollutants due to an increase in pH and a decrease in oxidation-reduction potential related to an application of nZVI. The assumed mechanisms of contaminants removal include precipitation of cations in a lower oxidation state, precipitation caused by a simple pH increase and co-precipitation with the formed iron oxyhydroxides. The possibility to control the reaction kinetics through the nature of the surface stabilizing shell (polymer vs. FeO nanolayer) is discussed as an important practical aspect.     

XAFS study of starch-stabilized magnetite nanoparticles and surface speciation of arsenate

It has been shown that starch can effectively stabilize nanoscale magnetite particles, and starch-stabilized magnetite nanoparticles (SMNP) are promising for in situ remediation of arsenic-contaminated soils. However, a molecular level understanding has been lacking. Here, we carried out XAFS studies to bridge this knowledge gap. Fe K-edge XAFS spectra indicated that the Fe-O and Fe-Fe coordination numbers of SMNP were lower than those for bare magnetite particles, and these coordination numbers decreased with increasing starch concentration. The decrease in the average coordination number at elevated stabilizer concentration was attributed to the increase in the surface-to-volume ratio. Arsenic K-edge XAFS spectra indicated that adsorbed arsenate on SMNP consisted primarily of binuclear bidentate (BB) complexes and monodentate mononuclear (MM) complexes. More BB complexes (energetically more favorable) were observed at higher starch concentrations, indicating that SMNP not only offered greater adsorption surface area, but also stronger adsorption affinity toward arsenate.     

Reducing phosphorus flux from organic soils in surface flow treatment wetlands

Treatment wetlands have a finite period of effective nutrient removal after which treatment efficiency declines. This is due to the accumulation of organic matter which decreases the capacity and hydraulic retention time of the wetland. We investigated four potential solutions to improve the soluble reactive P (SRP) removal of a municipal wastewater treatment wetland soil including; dry down, surface additions of alum or calcium carbonate and physical removal of the accreted organic soil under both aerobic and anaerobic water column conditions. The flux of SRP from the soil to the water column under aerobic conditions was higher for the continuously flooded controls (1.1 ± 0.4 mg P m⁻² d⁻¹), dry down (1.5 ± 0.9 mg P m⁻² d⁻¹) and CaCO₃ (0.8 ± 0.7 mg P m⁻² d⁻¹) treatments while the soil removal and alum treatments were significantly lower at 0.02 ± 0.10 and −0.07 ± 0.02 mg P m⁻² d⁻¹, respectively. These results demonstrate that the two most effective management strategies at sequestering SRP were organic soil removal and alum additions. There are difficulties and costs associated with removal and disposal of soils from a treatment wetland. Therefore our findings suggest that alum addition may be the most cost effective and efficient means of increasing the sequestering of P in aging treatment wetlands experiencing reduced P removal rates. However, more research is needed to determine the longer term effects of alum buildup in the organic soil on the wetland biota, in particular, on the macrophytes and invertebrates. Since alum effectiveness is time limited, a longer term solution to P flux may favor the organic soil removal.     

粗MnSO4溶液中MnS2O6的去除条件研究

用软锰矿吸收SO2生成MnSO4时会伴随有副产物MnS2O6生成。产品中MnS2O6的存在会降低硫酸锰产品质量,同时会缓慢释放出SO2气体污染环境。本文用单因素实验方法研究了粗MnSO4溶液中MnS2O6的最优去除条件。研究结果显示,软锰矿用量为12.2 g,硫酸加入量为20 mL、反应温度100℃、反应时间3 h、搅拌速度500 r/min,MnS2O6的去除率可达91%以上。其最终产品能达到GB1622-1986一级品标准。     

钛基IrO2-SnO2电极在烟气海水脱硫恢复系统中的应用

采用浸渍-热分解法制备了含IrOx-TiO2中间层的IrO2-SnO2电极,得到的电极具有较高的析氯电催化活性和较强的稳定性,并通过电化学氧化法对Na2SO3海水脱硫模拟液进行处理,考察了电流密度、温度、pH值和电解时间等电解工艺参数对Na2SO3去除率和化学需氧量COD的影响。结果表明,在电流密度为200 mA/cm^2,pH值为3.5,电解440 mg/L的Na2SO3海水脱硫模拟液,15 min时Na2SO3去除率可达96.5%,COD去除率可达82.6%。     

钛基IrO2-SnO2电极在烟气海水脱硫恢复系统中的应用

采用浸渍-热分解法制备了含IrOx-TiO2中间层的IrO2-SnO2电极,得到的电极具有较高的析氯电催化活性和较强的稳定性,并通过电化学氧化法对Na2SO3海水脱硫模拟液进行处理,考察了电流密度、温度、pH值和电解时间等电解工艺参数对Na2SO3去除率和化学需氧量COD的影响.结果表明,在电流密度为200 mA/cm...