间歇式生物反应器填埋结构对渗滤液水质的影响研究

通过2套间歇式生物反应器填埋模拟装置开展实验,对不同填埋结构下垃圾降解前期渗滤液pH值、COD、NH 4＋-N、VFA以及渗滤液产生量的变化规律进行了对比研究。实验结果表明：间歇式生物反应器填埋方式能够有效抑制填埋初期渗滤液pH值的快速下降,渗滤液采取部分回灌能有效降低NH4＋-N浓度的积累,新鲜垃圾与半腐熟垃圾分层并...     

三维电极-好氧生物法联合处理酸性染料废水模拟研究

采用电解-好氧生物法联合处理酸性大红G模拟废水，三维电解反应器填料为活性炭与玻璃珠混合物，平板电极材料为石墨，通过正交实验确定的最佳实验条件为：电解时间150min，活性炭／玻璃珠体积比为2：1，槽电压20V、pH为5、Na2SO4投加量1．5g／L，进水初始浓度2000mg／L。此时COD去除率及色度去除率分别可达49．78％和81．45％，废水BOD，／COD由0．12提高到0．42。电解后的废水采用生物接触氧化法处理12h后，出水COD为48mg／L，色度120倍，达到综合污水排放二级标准。     

好氧反硝化去除低浓度NO_x的动力学模型研究

在好氧条件下,对利用生物滴滤塔（bio-trickling filter,BTF）反硝化净化废气中NOx的过程进行了理论模型探讨,并用实验结果进行了验证。在分析NOx在BTF内传质以及生物降解过程的基础上,建立了NOx在气相和生物膜相的质量守恒方程,结合Fick定律和好氧条件下的Monod微生物反应动力学方程,最终得到了NOx在BTF中＂吸附-微生物降解＂过程的动力学方程。模型计算值与实验结果表明,BTF中好氧反硝化过程为一级反应过程,利用该模型可以较好地模拟进口浓度、停留时间等因素对出口浓度的影响,对实际应用具有指导意义。     

Aerobic and anaerobic degradation of profluralin and trifluralin

Abstract

The degradation of profluralin [N‐(cyclopropylmethyl)‐α,α,α‐trifluoro‐2,6‐dinitro‐N‐propyl‐]p‐toluidine] and trifluralin (α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine) was studied under aerobic and anaerobic soil conditions. Three soils (Goldsboro loamy sand, Cecil loamy sand, Drummer clay loam) were each treated with 1 ppmw herbicide; anaerobic conditions were maintained by flooding. Soil samples were extracted monthly and subjected to TLC analysis. No degradation was detected in sterile controls. Aerobic degradation of both herbicides was greatest in the Cecil loamy sand soil over the entire incubation period. Degradation of profluralin in Cecil soil under aerobic conditions was 86 percent after 4 months with three products detected; 83 percent of the trifluralin was degraded with two products detected. Anaerobic degradation accounted for 72 percent of the profluralin and 78 percent of the trifluralin after 4 months. Degradation of both herbicides increased with incubation time for the first 3 months and decreased slightly thereafter. Generally there was more extensive degradation (percent and in number of products formed) of profluralin than trifluralin under the conditions tested. More degradation products were detected for both herbicides under aerobic conditions than under anaerobic conditions.     

光电芬顿氧化法深度处理垃圾渗滤液研究

采用光电芬顿氧化法对北京市某垃圾填埋场已经生化处理后的垃圾渗滤液进行深度处理，分别考察了电流强度和铁的不同价态等因素对渗滤液总有机碳（TOC）、化学需氧量（COD）以及色度去除效果的影响，并对阳极氧化、电芬顿和光电芬顿不同反应过程进行了对比。通过分析渗滤液UV-Vis光谱(200～500 nm)变化和渗滤液中有机污染物的分子量变化，发现光电芬顿反应可以明显改善渗滤液生化性。深入研究了反应过程中铁价态的变化规律。试验结果发现，以高比表面积的活性炭纤维(ACF)为阴极的光电芬顿反应可以有效降解垃圾渗滤液，在pH为3，Fe²⁺ 浓度为1 mmol/L，电流为0.5 A，O₂通入量为250 mL/min条件下降解360 min，垃圾渗滤液TOC和COD去除率分别达到78.9%和62.8%，色度完全去除。     

矿化垃圾基本理化性状剖面变化特征研究

矿化垃圾能否作为农业资源被重新利用,除应考虑有效植物营养物质的含量与是否存在有害物质外,还取决于其基本理化性状。对城市生活垃圾填埋场中经填埋6年、8年、10年后得到的矿化垃圾基本物化性状变化特征进行分析,结果表明:矿化垃圾的土粒密度显著小于对照土壤,交换性盐基总量、CEC显著大于对照土壤,pH值和对照土壤基本相当;表层(0~50 cm)矿化垃圾的土粒密度、CEC、交换性盐基总量、pH值的变化幅度依次大于中层(50~100 cm)和下层(100~150 cm);矿化垃圾的理化性状在填埋8~10年后总体趋于稳定。从植物生长的环境角度看,填埋8~10年后的矿化垃圾可以开采后作为植物生长基质、土壤改良剂等农业资源化利用。     

Isolation and characterization of an Alcaligenes sp. strain DG-5 capable of degrading DDTs under aerobic conditions

In this study, an Alcaligenes sp. strain DG-5 that can effectively degrade dichlorodiphenyltrichloro-ethanes (DDTs) under aerobic conditions was isolated from DDTs-contaminated sediment. Various factors that affect the biodegradation of DDTs by DG-5 were investigated. About 88 %, 65 % and 45 % of the total DDTs were consumed within 120 h when their initial concentrations were 0.5, 5 and 15 mg L^?1, respectively. However, almost no degradation was observed when their concentration was increased to 30 mg L^?1, but the addition of nutrients significantly improved the degradation, and 66 % and 90 % of the total DDTs were degraded at 336 h in the presence of 5 g L^?1 peptone and yeast extract, respectively. Moreover, the addition of 20 mM formate also enhanced the ability of DG-5 to transform DDTs, and its DDT transformation capacity (T_c) value was increased by 1.8 - 2.7 fold for the pure (p,p’-DDT or o,p’-DDT only) and mixed systems (p,p’-DDT, o,p’-DDT, p,p’-DDD and p,p’-DDE). Furthermore, it was found that competitive inhibition in the biodegradation by DDT compounds occurred in the mixed system.     

丹阳北庄生活垃圾填埋场地下水污染分析

建立了针对生活垃圾填埋场地下水污染问题的数学预测模型,以丹阳北庄生活垃圾填埋场工程为例,预测和分析了北庄生活垃圾填埋场渗滤液对地下水的污染。     

城市污水污泥处置方式的温室气体排放比较分析

针对我国现在主流的城市污水污泥处置方法:填埋,焚烧,堆肥。用IPCC中推荐的方法和缺省值,对处置过程中产生的温室气体的直接排放、间接排放和替代排放做了计算和分析。填埋过程计算排放的温室气体有CH4,焚烧过程计算排放的有温室气体CO2和N2O,堆肥过程计算的排放的有温室气体CO2和N2O,最终比较的结果都折算成CO2的排放。结果表明,污泥填埋、焚烧、堆肥所产生的CO2的净排放量分别为695.847 kg CO2/t、443.643 kg CO2/t、511.817 kgCO2/t。由于考虑了堆肥以后的有机肥利用,从减排以及污泥资源化的角度分析,得出堆肥是相对好的污泥处置方式。     

好氧颗粒污泥表征技术研究进展

随着好氧污泥颗粒化技术的兴起,好氧颗粒污泥成为研究的热点之一。各国学者对好氧颗粒污泥应用了不同的表征手段,文章对好氧颗粒污泥的物理性质表征方法、物化性质表征方法、生化性质表征方法、性能参数表征方法以及PCR、FISH、DGGE等现代分子生物学技术在好氧颗粒污泥研究中的应用进行了综述。