武汉某湖泊底泥的机械脱水性能研究

通过测定污泥比阻值来评价污泥的脱水性能,探讨采用机械脱水的方法处理武汉某湖泊疏浚底泥的可行性和经济性。结果表明,底泥脱水性能良好,可以采用机械脱水的处理方法。CaO、PAC、FeCl3和PAM都可以进一步改善污泥的脱水性能,而CaO和PAC的处理效果更好,且PAC的成本更低。较佳的控制条件：温度为16～18℃,过滤压强为0．015MPa左右,PAC投加量为0．09％左右。采用机械脱水方式处理底泥,操作压强低、药剂投加量少、脱水效果好、经济可行。     

城市污水处理过程中污泥的理化特性研究

为研究城市污水处理过程中污泥理化特性的变化情况,采集了南京市江心洲污水处理厂各处理单元的污泥,分析了各种污泥的含水率、pH、EC、CEC、LOI、TN和TP的含量.结果表明,不同污泥的pH、EC、CEC、LOI、TN和TP含量存在明显差异,且随污水处理流程呈规律性变化.初沉池污泥、脱水前混合污泥和脱水污泥的pH、CEC略高于生化污泥和二沉池污泥的;而EC、LOI、TN和TP则低于生化污泥和二沉池污泥的.二沉池污泥和脱水前混合污泥的理化特性对比结果表明,该污水处理厂最终处理污泥(脱水污泥)的理化特性主要由初沉池污泥的理化特性决定.脱水处理会导致污泥中TP、CEC、pH的下降及EC的升高.     

含盐量对好氧颗粒污泥结构及处理效能的影响

研究了含盐量对好氧颗粒污泥结构的影响.研究发现高含盐量有助于提高颗粒污泥的沉速,减小孔隙率.从而形成更加密实的颗粒结构.对比结果表明,在低含盐量下颗粒污泥容易形成中空结构,这是低含盐量下颗粒污泥孔隙率大的根本原因.但高含盐量下形成的菌胶团颗粒污泥容易被丝状茵颗粒污泥所取代,因此控制丝状茵的过度繁殖是采用好氧颗粒污泥处理高盐度有机废水时需要注意的问题.     

传感器技术与污水处理过程控制技术的协同发展现状

仪表、控制和自动化(ICA)技术是污水处理厂降低运行成本、提高处理效率的有效手段,而ICA技术在污水生物处理领域的应用与发展,主要依赖于仪表技术尤其是传感器技术的发展.介绍了传感器技术在活性污泥法污水处理厂的应用现状,以及基于DO传感器、营养物传感器、间接参数测量传感器所发展起来的过程控制技术,并对传感器技术与过程控制技术在未来的协同发展趋势进行了讨论,以期为该技术的发展提供参考.     

添加碱渣对污泥厌氧消化的影响研究

将碱渣与城市污水处理厂的剩余污泥按不同的比例均匀混合后,进行厌氧消化试验,并根据消化液中SCOD、pH值及产气量等指标的变化,分析了碱渣对污泥厌氧消化性能的影响.结果表明:在碱渣添加量<8.25 g/L时,对污泥厌氧消化中的水解反应有较大的促进作用,溶出的有机物可生物降解性好;在试验的碱渣添加量范围内,厌氧消化液的pH值维持在7～8,显示碱渣对污泥消化产生的有机酸具有一定的缓冲作用;当碱渣添加量为3.30 g/L时,产气量和甲烷产量最大且厌氧消化反应速度最快,与未添加碱渣的相比则甲烷产量提高了约37.9%.碱渣中含有的碱性物质对污泥厌氧消化有较大的促进作用.     

利用东湖淤泥制备超轻陶粒的研究

利用东湖淤泥为主要原材料,进行堆积密度小于500kg/m3超轻陶粒研制。结果表明:按照发泡组分与东湖淤泥比例为20%∶80%,600℃预烧15min,1180℃焙烧12min,制备出了筒压强度1.7MPa、吸水率13.4%、堆积密度为485 kg/m3超轻陶粒。     

Analysis of wet oxidation process after initial thermohydrolysis of excess sewage sludge

The authors propose a new technique to analyse a complex process of wet oxidation of excess sewage sludge by separating thermohydrolysis that results in the separation of sewage sludge into hydrolysates: solid and liquid products, from the basic process of oxidation of the two products. Wet oxidation kinetics was studied at different temperatures of both products based on the measurement of total organic carbon during the process with the use of a PARR high-pressure reactor. Decomposition of the liquid product leads to the formation of non-degradable and gaseous final products, while degradation of the solid product-via an intermediate liquid product-also leads to the formation of final and gaseous products. Solution of the kinetic equations that describe the dependence of relative organic carbon concentration on time is well illustrated by experimental results. On the basis of fitting theoretical curves to the experimental results, the kinetic parameters of the process were determined.     

Continued development of a mass balance model of chemical fate in a sewage treatment plant

Chemicals that pass through a sewage treatment plant (STP) and into receiving waters lead to exposure of human and ecological receptors. Most countries require that such chemicals and especially those that are new to commerce be assessed for their treatability in STPs using a screening-level model. The STP model has been widely used for such assessments in Canada, the US and elsewhere. It is important for both industry and regulators that such a model be simple, accurate and applicable even with the limited data available for most chemicals. The STP model has been upgraded to include the capability to handle ionizing chemicals, and a variety of treatment plant configurations commonly used in Canada and elsewhere around the world. A scheme for obtaining appropriate biodegradation half-lives for the different treatment options from available aqueous biodegradation half-lives or standard biodegradability tests is suggested. Model simulations show good agreement with pilot-scale experimental data from literature for 20 organic chemicals with widely varying physico-chemical properties.     

Chlorinated-solvent-free gas chromatographic analysis of biomass containing polyhydroxyalkanoates

An extraction and derivatization method was developed for more environmentally friendly routine quantification of polyhydroxyalkanoates (PHAs) in activated sludge biomass by gas chromatography (GC). This method can be further applied to assess relative changes in biomass carbohydrate levels relating to, for example, glycogen or extracellular polysaccharides. Further, co-extracted principal membrane fatty acids are indicative of relative changes in active biomass. The protocol is attractive for routine assessment because it does not require any chlorinated solvents, which are still almost exclusively used today for PHA analysis by GC. Acidic alcoholysis of dried microbial biomass using 3:1 butanol to concentrated (37%) hydrochloric acid at 100 degrees C for 8 h will hydrolyse and derivatize microbial storage products and membrane lipids. Esters of the hydroxyalkanoates, carbohydrates converted to levulinic acid, and long chain microbial fatty acids are reliably extracted into hexane for gas chromatographic analysis and quantification. Calibration can be achieved with benzoic, 2-hydroxyvaleric, or 2-hydroxycaproic acids as the method reference standards.     

浅谈进水低浓度情况下的活性污泥培养

针对进水浓度偏低、进水水量不足是刚投入运行的污水处理厂普遍遇到的问题,对如何在此阶段将活性污泥培养起来进行了探讨,提出采用集中负荷形式、确保混合液流速、暂不考虑溶解氧含量、适时启动污泥回流,是活性污泥培养成功的有效方法.