活性污泥系统优化设计对不确定性参数的灵敏度研究

在活性污泥系统优化设计模型参数不确定性分析的基础上,考察了进水负荷、生物动力学参数、曝气设备性能参数和二沉池浓缩常数变化对优化设计的影响。灵敏度分析结果表明,对优化设计影响较大的参数为：进水水量水质、与氧转移效率相关的校正参数以及二沉池的浓缩常数等。研究结果对于低灵敏度系统的设计,提高优化设计结果的工程实用性具有重要的意义。     

Evaluation of activated sludge properties’ changes in industrial-wastewater pre-treatment: role of residual aluminum hydrolyzed species with different polymerization degree

● Medium poly Al salts dominated the PAC residual salts with a rational dosage. ● Settlement flocculation effect under medium poly Al salts showed a better trend. ● Complex of medium poly Al salts and enzymes promoted cell activity. ● Medium poly Al salts were beneficial to the effluent indexes. With the widespread introduction of pre-coagulation prior to the biological unit in various industrial wastewater treatments, it is noteworthy that long-term accumulation of residual coagulants has certains effect on both micro and macro characteristics of activated sludge (AS). In this study, the morphology distributions of residual aluminum salts (RAS) and their effects on the removal efficiency of AS were investigated under different PAC concentrations. The results showed that the dominance of medium polymeric RAS, formed under an appropriate PAC dose of 20 mg/L enhanced the hydrophobicity, flocculation, and sedimentation performances of AS, as well as the enzymatic activity in cells in the sludge system, improving the main pollutants removal efficiency of the treatment system. Comparatively the species composition with monomer and dimer / high polymer RAS as the overwhelming parts under an over-dosed PAC concentration of 55 mg/L resulted in excessive secretion of EPS with loose flocs structure and conspicuous inhibition of cellular activity, leading to the deterioration of physico-chemical and biological properties of AS. Based on these findings, this study can shed light on the role of the RAS hydrolyzed species distributions, closely relevant to Al dosage, in affecting the comprehensive properties of AS and provide a theoretical reference for coagulants dosage precise control in the pretreatment of industrial wastewater.     

A procedure to design a Permeable Adsorptive Barrier (PAB) for contaminated groundwater remediation

A procedure to optimize the design of a Permeable Adsorptive Barrier (PAB) for the remediation of a contaminated aquifer is presented in this paper. A computer code, including different routines that describe the groundwater contaminant transport and the pollutant capture by adsorption in unsteady conditions over the barrier solid surface, has been developed. The complete characterization of the chemical–physical interactions between adsorbing solids and the contaminated water, required by the computer code, has been obtained by experimental measurements. A case study in which the procedure developed has been applied to a tetrachloroethylene (PCE)-contaminated aquifer near a solid waste landfill, in the district of Napoli (Italy), is also presented and the main dimensions of the barrier (length and width) have been evaluated. Model results show that PAB is effective for the remediation of a PCE-contaminated aquifer, since the concentration of PCE flowing out of the barrier is everywhere always lower than the concentration limit provided for in the Italian regulations on groundwater quality.     

烧结机头烟气脱硫脱硝技术比较分析

本文提出了目前常见的两种烧结机头烟气脱硫脱硝超低排放工艺技术:CFB脱硫+SCR脱硝工艺和活性焦脱硫脱硝一体化工艺,并对两种脱硫脱硝技术的工艺过程和工艺特点进行了比较和分析。     

活性污泥中需氧量的研究现状及供氧系统的节能技术

叙述了国内外活性污泥法中需氧量的研究过程及微孔曝气系统的节能技术，对微孔曝气器与穿孔曝管进行对比，证实前者较后者节电４４％．     

Plastic shaping of aqueous alumina suspensions with sucrose and maltodextrin additives

Traditional methods for the shape-forming of engineering ceramics entail plastic deformation of powder slurries containing hazardous organic liquids as suspending media. Replacing these organic with aqueous media requires the development of environmentally benign, water-soluble additives which serve as plasticizers and binders. Fundamental studies were performed with aqueous suspensions of colloidal-Al₂O₃ to evaluate the role of sucrose and maltodextrin on viscosity, sedimentation, and filtration characteristics, plastic flow behavior of filter cakes, and sinterability. Maltodextrin systems exhibited superior results, including filtration to high packing densities and clay-like plasticity with minimal cracking.Paper presented at the Bio/Environmentally Degradable Polymer Society—Third National Meeting, June 6–8, 1994, Boston, Massachusetts.Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract W-7405-Eng-82.     

SBR及其改良型技术分析

通过分析研究SBR及其衍生的各种改良型技术用于污水处理的运行方式及特点,指出SBR及其衍生的改良型技术可在中小型污水处理领域降低建设成本和运行费用,是一种适合中国国情的绿色小区污水回用处理技术.     

仇山膨润土矿不同酸度活化后蒙脱石形态及其变化

浙江仇山膨润土经不同酸度活化,蒙脱石在酸度为17.5～20％时其颗粒大小、厚度趋于一致;酸度分别为12.5％,20％时集合体由絮状,团块状向厚片状,片状变化;酸度为12.5～17.5％时其颗粒边缘变为光滑,而酸度为25％时则变为锯齿状;酸度20％时,表面更加光滑,平整。蒙脱石形态直接反映它的表面积的变化,决定了活性白土脱色性能的优劣。本文讨论了蒙脱石表面积与活性白土脱色力的变化关系。     

微生物固定化技术及其对土霉素生产废水处理的研究

本文提出活性炭核一海藻酸钙包埋微生物固定化技术，并将以假丝酵母为主的混合菌群固定化，然后分别在低氧与好氧状态对土霉素生产废水的处理进行了试验研究。结果表明，经固定的微生物，其使用温度、pH值适应范围扩大，对有机物的降解能力亦优于未固定微生物。室温下，当进水CODcr(化学需氧量)为2400～5500mg／1时，在低氧与好氧状态停留24h，其去除率分别达88．2％和97．3％。     

混凝气浮-推流式活性污泥-深度处理法处理染色废水

介绍了混凝气浮-推流式活性污泥-深度处理法在染色废水工程中的应用，分析了工程的设计及运行的情况。实践表明，混凝气浮预处理可以有效去除色度、悬浮物和部分有机物，提高抗冲击负荷能力；推流式活性污泥法有较高的处理效率，经深度处理后，废水达标排放。