SBBR与SBR氧传质特性比较研究

在试验条件相同的情况下,进行了序批式膜生物反应器SBBR与SBR的清水充氧试验,氧传质特性比较研究结果表明:当曝气强度为0.3m3/h时,SBBR的(KLa)20和Eo2值均为SBR的1.59倍。SBBR具有更好的氧传质能力和更高的氧转移效率。     

电镀污泥中铬的去除工艺优化

以某公司的电镀污泥为研究对象,针对污泥中含铬量高的特点,提出了去除铬的处理工艺.根据铬在污泥中存在的状态,采用硫酸作为浸出试剂.通过正交试验,考察了硫酸浓度、浸出时间、反应温度、搅拌速率等对铬去除率的影响,同时也对去除机理进行了探讨.X射线光电子能谱(XPS)显示,电镀污泥中铬的质量分数为22.05%;取此种污泥2g,用10mol/L的硫酸溶解,在固液比(质量分数)为15∶1,搅拌速率为800r/m,待反应90min后,可使污泥中各种形态的铬溶解于硫酸中,从而去除污泥中的铬.此种方法操作简单可行,污泥中铬的去除率可达90%以上.浸出的铬可进一步综合利用,剩余污泥也可安全填埋,有利于减少此类污泥对环境甚至生态系统的危害.     

养殖场鸡粪废水厌氧发酵产氢性能

在养殖场鸡粪废水中添加米糠提高废水的碳氮比,以经过不同预处理的厌氧活性污泥为接种物,控制发酵温度为36℃,初始pH为5.0,考察污泥预处理及底物质量浓度对发酵产氢的影响,并分析液相末端产物及发酵液化学需氧量(chemical oxygen demand,COD)去除率.研究结果表明,污泥的最佳预处理方法为热处理(100℃下加热15 min),发酵累积生物气产量和氢气产量分别为1 781和1 082.8 mL,是未处理组的2.52和5.85倍;鸡粪废水的适宜质量浓度为10 218 mg/L,此时氢气产量为185.1 mL/g,由Gompertz模型对产气量进行非线性拟合得拟合方程,说明该模型可很好地模拟发酵产氢过程;发酵结束后液相末端产物主要转化为乙酸和丁酸等挥发性有机酸,在不同底物质量浓度下COD去除率随底物质量浓度先增加后减小,在质量浓度为10 218 mg/L时达到26.9%.     

城市污泥热解过程中重金属的形态转化模拟研究

利用重金属Cd,Cu,Zn和Pb的碳酸盐、可溶性盐（如硫酸盐、硝酸盐、氯化盐）或硫化物作为污泥中重金属的模拟化合物,在不同条件下对模拟化合物进行热解.通过对热解产物进行X-射线衍射分析,确定产物的组成,从而推断污泥热解时重金属的形态变化过程.结果表明：Cd的碳酸盐热解过程中向更加稳定的CdS发生转变;Cu的碳酸盐和硫化物生成Cu2S;Zn的离子交换态和Pb的碳酸盐与离子交换态热解之后均生成相应的氧化物和硫化物.     

污泥热干燥粘结的特征和影响因素

污泥热干燥过程中在干燥设备内部表面的粘结是影响干燥设备性能的重要因素。通过热干燥模拟实验,分析了污泥含水率、加热温度、加热方式、加热界面性质等因素对污泥粘结的影响。结果表明,含水率是影响污泥粘结最主要的因素,污泥含水率较高时,粘结量较少,随着污泥干燥程度增加,含水率降低,粘结量逐渐增加,当含水率达到60%左右时粘结量达到最大,之后转而减少;加热温度不超过120℃时,温度对污泥粘结的影响不明显,加热温度高于120℃时,污泥粘结量随温度升高而显著增加;传导加热方式比对流加热方式更易导致污泥粘结;加热接触界面的表面粗糙度越大则污泥粘结量越大。     

Cytochemical investigation of the digestive gland of two strombidae species (Strombus gigas and Strombus pugilis) in relation to the nutrition

Strombus gigas and Strombus pugilis are threatened species and aquaculture represents a good alternative solution to the fishing. In this study, we highlighted the intracellular digestion process in the digestive gland of two Strombidae species, S. gigas and Strombuspugilis, by the cytochemical characterization of two lysosomal enzymes: acid phosphatase and arylsulfatase. In order to check the efficiency of artificial food digestion, we conducted the characterization on freshly collected, starved and artificially fed individuals of S. pugilis. TEM observations of digestive gland sections from freshly collected individuals of both species revealed the presence of acid phosphatase and arylsulfatase activity mostly located in the apical third of digestive cells. Both enzymes were also detected in artificially fed individuals. In response to the starvation, acid phosphatase is not produced anymore by digestive cells, while arylsulfatase is still present. To our knowledge, this is the first cytochemical validation of intracellular digestion of artificial food in Strombidae. This study highlights the intracellular digestion of artificial food developed for Strombidae aquaculture. Moreover, we have shown that the lysosomal activity could be used as a feed index. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.     

Properties and mechanism of red mud in preparation of ultra-lightweight sludge-red mud ceramics

New ultra-lightweight sludge-red mud ceramics (ULS-RMC) were prepared by red mud (RM), clay and dried sewage sludge (DSS). The properties and mechanism of RM in the preparation of ULS-RMC were discussed. The chemical components, thermal properties and mineral phases of RM were determined by energy dispersive X-ray (EDX), differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA) and X-ray diffraction (XRD), respectively. Constant dosage of DSS to clay and different amounts of RM were utilized in the preparation of ULS-RMC. Physical properties test (bulk density, grain density, water absorption and expansion ratio), XRD and scanning electron microscopy (SEM) were employed to characterize the ULS-RMC. The results show that RM exhibits high hydroscopic property and good water-retention property, and bloating property and fluxing property of RM are caused by abound of gaseous components and flux, respectively. The two chemical properties are utilized to discuss the mineral phases and microstructures differences between ULSC and ULS-RMC.     

好氧颗粒污泥脱氮除磷效率研究

以实验室模拟废水为进水,在SBR反应器中利用好氧颗粒污泥进行N、P的去除效率研究.研究表明:在运行周期约为4h,进水COD控制在500～1200 mg/L之间,室温条件下,好氧颗粒污泥对COD、氨氮、硝氮、TP的去除率稳定维持在97％、95％、92％、86％,说明好氧颗粒污泥特有的结构特性和生物特性有利于脱氮除磷.     

浸提时间对城市污泥重金属浸出特性的影响

在研究含工业废水污泥中Zn、Cu、Pb、Cr、Mn、Ni含量的基础上,应用固体废物浸出毒性方法,以不同浸出时间对污泥中重金属的浸出特性进行了实验研究.结果表明:污泥中Mn和Zn含量较高,其次为Cu和Ni,而毒性较大的Pb和Cr含量较低.浸提时间对污泥中重金属的浸出具有重要影响,污泥中的Zn、Cu、Ni最大浸出浓度在8h时,而Fe和Mn随着浸提时间增加而增加;浸提时间对污泥中重金属浸出量的影响因该重金属的化学性质不同而存在较明显的差别,这可能与浸提过程中的吸附-解吸过程、络合-解离过程和溶解-沉淀/共沉淀等因素有关.     

Extended activated sludge model no. 1 (ASM1) for simulating biodegradation process using bacterial technology

Phosphorus is one of the most important nutrients required to support various kinds of biodegradation processes. As this particular nutrient is not included in the activated sludge model no. 1 (ASM1), this study extended this model in order to determine the fate of phosphorus during the biodegradation processes. When some of the kinetics parameters are modified using observed data from the restoration project of the Xuxi River in Wuxi City, China, from August 25 to 31 in 2009, the extended model shows excellent results. In order to obtain optimum values of coefficients of nitrogen and phosphorus, the mass fraction method was used to ensure that the final results were reasonable and practically relevant. The temporal distribution of the data calculated with the extended ASM1 approximates that of the observed data.