包气带砂层中垃圾渗滤液自然衰减作用研究

通过实验定量分析了包气带砂层中影响垃圾渗滤液污染物自然衰减的吸附作用和生物降解作用。通过静态吸附实验计算得到砂层对COD和NH4+的理论最大吸附量为52.36和35.34 mg/kg。在生物降解作用研究中,确定HgCl2为生物作用抑制剂,最佳抑制浓度为10 mg/L。通过模拟柱对比得出包气带砂层中,生物降解是垃圾渗滤液污染物自然衰减的主要机制。生物作用和自然衰减条件下,垃圾渗滤液中COD在包气带砂层中的一级衰减动力学方程分别为:ρ(COD)=642221e-0.0017t和ρ(COD)=642221e-0.0021t。     

Minimizing N_20 fluxes from full-scale municipal solid waste landfill with properly selected cover soil

Municipal solid waste landfills emit nitrous oxide(N_2O)gas.Assuming that the soil cover is the primary N_2O source from landfills, this study tested,during a four-year project,the hypothesis that the proper use of chosen soils with fine texture minimizes N_2O emissions.A full-scale sanitary landfill,a full-scale bioreactor landfill and a cell planted with Nerium indicum or Festuca arundinacea Schreb,at the Hangzhou Tianziling landfill in Hangzhou City were the test sites.The N_2O emission rates from all test sites were considerably lower than those reported in the published reports.Specifically,the N_2O emission rate was dependent on soil water content and nitrate concentrations in the cover soil.The effects of leachate recirculation and irrigation were minimal.Properly chosen cover soils applied to the landfills reduced N_2O flux.     

膜分离腐殖质前后晚期渗滤液可生化性的变化

晚期渗滤液由于含有大量难降解有机物腐殖质,可生化性差,较难处理。采用特定分子量的超滤膜对晚期渗滤液中的腐殖质进行有效的分离,研究了膜分离腐殖质前后渗滤液的可生化性的变化：渗滤液中腐殖质类物质去除率为90．7％,BOD5/COD值提高了6倍,可生物降解的有机物在总有机物中所占比率提高了约4倍。结果表明,分离腐殖质可提高渗滤液的可生化性。     

PAC-SBR与SBR处理垃圾渗滤液对比研究

利用PAC-SBR与SBR对垃圾渗滤液进行了对比试验研究,从处理效果、微生物性状以及生化反应表征特性进行了研究,结果表明,同条件SBR法相比,PAC-SBR法可以取得更高的有机物去除、脱氮和脱色效果。COD、色度和NH3去除率分别可达到81.6%、48.6%和90%以上。     

Performance of landfill leachate treatment system with disc-tube reverse osmosis units

Reverse osmosis system with the disc-tube module (DT-RO) was applied to treat landfill leachate on full scale at the Changshengqiao Sanitary Landfill, Chongqing City, China. In the first six-mouth operation phase, the treatment performance of DT-RO system had been excellent and stable. The removal rate of chemical oxygen demand (COD), total organic carbon (TOC), electrical conductivity (EC), and ammonia nitrogen (NH₃-N) reached 99.2–99.7%, 99.2%, 99.6%, and over 98%, respectively. The rejection of Ca²⁺, Ba²⁺, and Mg²⁺ was over 99.9%, respectively. Suspended solid (SS) was not detected in product water. Effective methods had been adopted to control membrane fouling, of which chemical cleaning is of utmost importance to guarantee the long smooth operation of the DT-RO system. The DT-RO system is cleaned in turns with Cleaner A and Cleaner C. At present, the 1st stage cleaning cycle by Cleaner A and Cleaner C is conducted every 100 and 500 h, respectively, depending on raw the water quality.     

垃圾渗滤液净化物理化学处理方法研究

根据垃圾填埋场渗滤液成分复杂,有机物中氨氮浓度高,COD及BOD值较大,而且含有一定重金属离子的特点,采用物理化学处理方法进行处理。将有机物、重金属化学沉降,同时将滤液中的铵根离子转化为氨气,用鼓气的方法赶出氨气,再用絮凝剂混凝沉降的方法对渗滤液进行处理。经优化条件实验出水后的渗滤液基本达到《生活垃圾填埋污染控制标准》二级排放标准。     

混凝—催化臭氧化处理垃圾渗滤液MBR出水

本文研究了混凝—催化臭氧化对垃圾渗滤液MBR出水COD、UV254和色度的去除效果及可生化性能的影响。在pH 11,FeCl3用量800 mg/L的优化条件下,COD、UV254和色度去除率分别为37.8%、61.9%和88.7%。混凝出水催化臭氧化结果表明,3%-Ce/AC催化臭氧化效率最好,COD去除率为33.6%,臭氧消耗系数为1.40 mgO3/mgCOD。经混凝—催化臭氧化处理后,MBR出水的COD、UV254及色度总去除率分别为58.7%、90.8%及98.7%,BOD5/COD从0.036提高到0.375,可生化性明显改善。     

Influence of seasonal temperature change on autotrophic nitrogen removal for mature landfill leachate treatment with high-ammonia by partial nitrification-Anammox process

In this study, a denitrification (DN)–partial nitritation (PN)–anaerobic ammonia oxidation (Anammox) system for the efficient nitrogen removal of mature landfill leachate was built with a zone-partitioning self-reflux biological reactor as the core device, and the effects of changes in seasonal temperature on the nitrogen removal in non-temperature-control environment were explored. The results showed that as the seasonal temperature decreased from 34°C to 11.3°C, the total nitrogen removal rate of the DN-PN-Anammox system gradually decreased from the peak value of 1.42 kg/(m³?day) to 0.49 kg/(m³?day). At low temperatures (<20°C), when the nitrogen load (NLR) of the system is not appropriate, the fluctuation of high NH₄⁺-N concentration in the landfill leachate greatly influenced the stability of the nitrogen removal. At temperatures of 11°C–15°C, the NLR of the system is controlled below 0.5 kg/(m³?day), which can achieve stable nitrogen removal and the nitrogen removal efficiency can reach above 96%. The abundance of Candidatus Brocadia gradually increased with the decrease of temperature. Nitrosomonas, Candidatus Brocadia and Candidatus Kuenenia as the main functional microorganisms in the low temperature.     

不同水力负荷渗滤液对植物土壤系统的影响

以稳定产甲烷阶段垃圾层循环回灌处理后的渗滤液、轻壤土和百慕大草(Cynodon dactylon)为实验材料,比较了不同水力负荷渗滤液对植物-土壤系统的生态影响.结果表明,2.77～12.00 mm·d^-1渗滤液灌溉组土壤的几种关键酶活性、呼吸作用强度、土壤微生物量、微生物商,叶绿素含量均较对照组高,丙二醛(MDA)、过氧化氢(H₂O₂)、脯氨酸(Pro)含量较低;在渗滤液灌溉组间,6.46～10.15 mm·d^-1渗滤液灌溉下百慕大草Pro含量下降显著,叶绿素含量明显提高,过氧化物酶(POD)活性、MDA和H₂O₂含量较低,土壤酶活性显著提高、呼吸作用强度、微生物量和微生物商较大;而当渗滤液水力负荷过低(2.77～4.16 mm·d^-1)或过高(12.00 mm·d^-1)时百慕大草胁迫会加重、土壤生物活性下降.表明适量渗滤液灌溉可减缓环境对百慕大草的胁迫,提高土壤的生物活性,表现出对植物-土壤系统的生态正效应,其原因可能与不同水力负荷渗滤液灌溉改变了土壤的水分和理化性质.研究说明,通过控制渗滤液原液水力负荷,可望获得渗滤液灌溉对植物-土壤系统最佳的生态效应.     

含砷污泥制砖的毒性浸出试验研究

将含砷污泥和粘土按一定比例混合制砖,并对样品砖的毒性浸出进行了研究。结果表明对As、Zn、Pb、Cd离子的固化效果好,浸出毒性低于国家标准。还分析了浸出液的pH值、Eh和溶解氧对重金属离子浸出浓度的影响。