Implications of the task group model-I. The effect of initial substrate concentration

This paper explores the merit of the task group model to reflect the effect of the initial substrate concentration on the performance of microbial systems, assessed in terms of the effluent soluble COD. In this context, a structural modification is proposed to account for this effect, by incorporating mechanisms responsible for the generation of soluble microbial products, considered residual for the particular operating conditions of the activated sludge systems. Model simulations of a number of practically significant scenarios are performed and evaluated. Reasonably good agreement is depicted between the model outputs and experimental data from previous studies.     

The effect of reactor hydraulics on the performance of activated sludge systems—II. The formation of microbial products

A new model involving the concept of soluble residual microbial products formation was used to investigate the effect of reactor hydraulics on the substrate removal efficiencies of activated sludge systems. Strong experimental evidence in the literature suggests that what is measured in most studies is not the remaining portion of the influent degradable substrate, but organic matter of microbial origin which is residual, at least for the operating conditions considered. An appropriate simulation approach was formulated to account for the formation of these products, by a simple mechanistic modification of the newly proposed task group model. This model showed no practical difference between the performances of completely mixed and plug flow activated sludge systems, because they produced almost equal amounts of these microbial products, under similar operating conditions.     

Factorial experimental design of winery wastewaters treatment by heterogeneous photo-Fenton process

Winery wastewaters are difficult to treat by conventional biological processes because they are seasonal and experience a substantial flow variations. Photocatalytic advanced oxidation is a promising technology for wastewaters containing high amounts of organic matter. In this work, the photo-Fenton process in heterogeneous phase is presented as an alternative methodology for the treatment of winery wastewaters. As a consequence of the great number of existing variables, an experimental design methodology has been used in order to study the influence and interaction of various variables and to obtain a reduced empirical model which describes the organic matter degradation process. Applying photo-Fenton treatment in heterogeneous phase under energetic conditions for synthetic samples simulating winery wastewaters results in purification levels of up to 50% (measured as total organic carbon). Different reduced models are obtained and their utilization depends mainly on the degree of degradation of organic matter required.     

An/O生物除磷中两个主要控制因素的研究

在An/O生物除磷工艺的影响因子中,进水COD/TP与生化反应系统的BOD负荷是关键。试验结果表明:COD/TP越大,厌氧释磷越多,越有利于除磷,厌氧释磷量是吸收COD量的函数;并且,进水COD/TP的变化对系统COD的去除不会产生明显的影响。试验中还发现,厌氧条件下PHB的产生并不完全依赖于高能磷酸键水解提供的能量,COD浓度越高则越有利于PHB的贮存。若要达到好的除磷效果,系统的BOD负荷必须控制在0.21～0.5kgBOD5/(kgMLSS·d)之间,且BOD负荷越高,除磷效果越佳。     

压裂返排液生物处理实验研究

从油田压裂返排液中筛选出EB系列菌种,可高效降解压裂返排液中的高分子和有机污染物.考察了振荡时间、温度、接种量、菌种混合比例等对压裂返排液COD去除率的影响.结果表明:48 h振荡、25℃、10％接种量、菌种EB1和EB2按1∶1比例混合是较佳应用条件.EB复合菌种的应用范围较广,其pH值适用范围为6～9,矿化度适用范围为3000～20000 mg/L.该研究提高了压裂返排液生物处理技术规模化应用的可行性.     

Soluble microbial products (SMP) formation kinetics by biofilms

Soluble microbial products (SMP) formation kinetics were investigated by employing a laboratory-scale biofilm reactor and naturally-grown oligotrophs. The experimental results indicated that the majority of effluent soluble organic carbon(SOC) was SMP, while only a small fraction of the effluent SOC was the residual original substrate. Utilization-associated products (UAP), which were produced directly from substrate metabolism, were more important than biomass-associated products (BAP), which were produced by basic metabolism. The SMP contained mainly high-molecular-weight organic compounds, although the organic carbon source to a biofilm reactor was a low-molecular-weight compound. The steady-state concentrations of the effluent SMP and SOC were directly proportional to the influent substrate concentrations in this study. An extended steady-state biofilm model was developed by incorporating into the steady-state biofilm model an SMP formation model based on two types of SMP (i.e. UAP and BAP). The model described successfully the experimental substrate utilization, SMP formation, and the removal of total soluble organic matter (SOC).     

Characterization of dairy waste streams, current treatment practices, and potential for biological nutrient removal

Fifteen milk processing plants in the Upper Midwest of the United States participated in a study to obtain information on general process operation, waste generation and treatment practices, chemical usage, and wastewater characteristics. Long term data on wastewater characteristics were obtained for 8 of the 15 dairy plants, and a 24-h composite wastewater sample was characterized in detail for each plant. Wastewater flow rates and characteristics varied greatly among and within plants and were not easily predictable even when detailed information on processing operations was available. In addition, the contribution of milk and milk products to the waste streams was underestimated by plant operators. The use of caustic soda, phosphoric acid, and nitric acid for cleaning had a significant impact on wastewater characteristics, despite the implementation of changes in chemical usage practices during recent years. In particular, the use of phosphoric acid based cleaning products has been reduced to eliminate or decrease discharge fines. It was determined that most of the on site treatment facilities require renovations and/or operational changes to comply with current and future discharge regulations, especially with respect to nutrient (nitrogen and phosphorus) levels in their waste streams. It was concluded that biological nutrient removal of dairy wastewaters should be feasible given the relatively high concentrations of easily degradable organics, the generally favorable organic matter to total phosphorus ratio, and the very favorable organic matter to nitrogen ratio.     

Biological removal of phenol from strong wastewaters using a novel MSBR

In this study, the performance of a moving-bed sequencing batch reactor (MSBR) that removes phenol from wastewater is presented. The effects of phenol concentration (50-3325 mg L⁻¹), filling time (0-4 h) and aerating time (4-18 h) on the performance of the MSBR are given in terms of phenol and COD removal efficiencies. Moreover, the effect of the moving media on the overall performance of the reactor is also determined. The reactor can completely remove phenol and COD at inlet concentrations up to 3000 mg phenol L⁻¹ (6780 mg COD L⁻¹), which was the inhibition concentration, and with a 24-h cycle time. The filling time range tested here did not significantly affect phenol or COD removal. The optimum hydraulic retention time (HRT) for the MSBR is 40 h and the critical phenol loading rate is 83.4 g phenol m⁻³ h⁻¹, which gives a phenol removal efficiency of 99%. The reactor can also withstand shock loads from slug feeding. The moving bed contribution to phenol and COD removal efficiencies was up to 28.1 and 34.7%, respectively, at the phenol loading rate of 83.4 g m⁻³ h⁻¹. The findings of this investigation suggest that MSBR can be a robust and promising process for effectively treating wastewaters containing inhibitor or recalcitrant compounds in industrial settings.     

城市园林害虫的生物合理控制策略

通过对城市园林及其害虫发生状况的分析，提出了以建设生态园林和应用生物合理农药为核心的园林控制策略，达到无害化控制园林害虫、优化城市环境目的。     

味精废水生物除碳脱氮动力学特性的研究

为优化某味精废水处理工程的操作,研究了其除碳脱氮动力学特性.结果表明,对COD的最大比去除速率为0.110 kgCOD/(kgVSS·h),最大容积去除速率与实际容积负荷之比为17.28～21.12,最大比去除速率与实际污泥负荷之比为13～21,饱和常数KS为202 mgCOD/L;对氨氮的最大比去除速率为0.014 1 kgNH4+-N/(kgVSS·h),最大容积去除速率与实际容积负荷之比为8.86～11.25,最大比去除速率与实际污泥负荷之比为7～11,KS为19.1 mgNH4+-N/L,表明该工程去除COD和氨氮的潜力还很大,容易实现达标排放.当以葡萄糖为碳源时,对硝态氮的最大比去除速率为0.014 0 kgNO3--N/(kgVSS·h),KS为13.5 mgNO3--N/L;当以醋酸盐为碳源时最大比去除速率为0.024 4 kgNO3--N/(kgVSS·h),KS为12.0 mgNO3--N/L,表明醋酸盐比葡萄糖更有利于提高反硝化速率和强化脱氮效果.     

Biological Wastewater Treatment under the Influence of Pressure

An investigation is reported into the effect of pressures of up to 6 bar on the operation of a laboratory-scale rotating biological contactor. All results are compared with those of an identical reactor operating at atmospheric pressure. Few previous results relating to the effect of pressure on biological wastewater treatment could be found in the literature. Although improved BOD and COD removal (compared to that of the reference unit) was evident as the pressure was increased, the principal benefits of increasing pressure were recorded as being (a) significantly improved nitrification, and (b) a decrease in the sludge yield coefficient. Both these factors improved regularly with increasing pressure, although there is some indication that the production of total oxidized nitrogen might have been affected at the highest pressure employed.     

淹没式膜生物反应器膜面泥饼层的微结构特征

为研究膜生物反应器运行中的膜污染问题,利用扫描电镜（SEM）和原子力显微镜（AFM）分析了膜在污泥混合液及上清液中所形成泥饼层的微结构特征.结果表明,两种类型泥饼层的微结构存在显著差异且与膜污染速度相关,膜面泥饼层微结构的表征技术可以作为膜污染评价的重要手段.在污泥混合液中形成的膜面泥饼层厚度大但表面粗糙度高,存在一定的孔隙性;而在上清液中形成的膜面泥饼层虽然更薄但相对致密,其渗透性差,导致膜污染速度加快.活性污泥混合液及上清液中,膜截留的溶解性微生物代谢产物（SMP）的分子质量分布趋势相近,膜面泥饼层微结构的差异主要与被过滤液中微生物絮体的体积和含量有关.     

物化与生物法组合处理研磨涂装废水

采用物化法与生物法组合工艺处理研磨、涂装废水，并改进了水解酸化池和沉淀池的设计。运行结果表明，在进水有机物浓度较高、具有一定生物毒性的情况下，出水水质仍可达到GB8978-1996的一级排放标准，对COD和BOD5的去除率均超过97％。     

曝气量对膜生物反应器污泥特性和膜污染的影响

设置M1、M2和M3等3个反应器的曝气量分别为150、200和300 L/h,研究了曝气量对膜生物反应器(MBR)的运行效果和污泥特性的影响.结果表明,随着曝气量的增加,对COD和NH4+-N的去除率提高,反应器内溶解氧浓度和污泥的比耗氧速率均增加,表明增加曝气量有助于提高污泥的活性.污泥絮体的粒径变小,溶解性微生物代谢产物(SMP)浓度则由M1的46.8mg/L增加到M3的71.0 mg/L,而且其中的成分也发生了变化,蛋白质与多糖的比值随着曝气量的增加而增加,M1的为1.5,M3的则增至1.9.随着曝气量的增加则膜污染速率加快,表明膜污染以SMP污染为主.     

化学生物絮凝工艺对溶解性有机物的去除特性

研究了化学生物絮凝工艺对溶解性有机物的去除效果及其分子质量分布的变化特征，并分别与化学强化一级工艺、初沉池和二级生物处理工艺的出水进行对比。试验结果显示：化学生物絮凝工艺对分子质量〉2ku的有机物去除效果明显；对溶解性有机物和UV260的去除率分别为45．9％和38．7％，与城市污水二级生物处理工艺相比，其去除溶解性有机物的能力较弱；对溶解性有机物的去除是通过化学和生物作用共同实现的，其中生物作用主要表现为生物吸附作用。     

全流程生物氧化法处理微污染原水研究

许多水厂已经或正在准备采用生物接触氧化预处理（BCO）技术来提高水质，由于对生化处理缺乏深入了解及受传统预加氯处理的限制，现在已经运行的生化处理工艺并不能有效地去除有机污染物。在对预加氯与否所测得试验数据进行分析的基础上，提出了全流程生物氧化（EPBO）的处理工艺。     

ME/Fenton/AF/BAF工艺处理炼油废水研究

采用微电解/芬顿/厌氧/好氧生物滤池工艺(ME/Fenton/AF/BAF)处理炼油废水,探讨了各工段的工艺参数及工艺整体运行效果。试验得到最佳工艺参数如下:微电解单元的初始pH值为3,Na₂SO₄投加量为0. 05 mol/L;双氧水的投加量为1. 5 m L/L; AF/BAF工段的水力停留时间为(2+2) h。在上述工艺条件下,ME/Fenton/AF/BAF工艺连续运行处理炼油废水时对COD、氨氮、油的平均去除率分别为85. 2%、85. 0%、90. 1%。     

曝气方式对一体式膜生物反应器运行特性的影响

采用两个结构相同的一体式膜生物反应器处理生活污水，考察了不同曝气方式对运行效果的影响。结果表明，采用连续高强度曝气方式运行的MBR与采用间歇高强度曝气方式运行的MBR在对COD、氨氮和TN的去除效果方面相差不大；但间歇高强度的曝气方式减少了混合液中胞外聚合物（EPS）的释放和溶解性微生物产物（SMP）的溶出，有效缓解了膜污染，其单位产水能耗约为前者的60％。     

帕克活性生物砂滤脱氮工艺的设计与运行

位于鹿特丹西部的De Groote Lucht污水厂的原处理工艺无法满足新的氮排放标准，因此进行了改扩建工程，增加了活性生物砂滤床作为三级处理工艺。改造后的处理系统既能达到很高的脱氮效率，又能较好地去除SS和COD，运行稳定，人工操作简单，可满足年平均总氮含量〈10mg／L的标准要求。     

Effect of soluble microbial products on microbial metabolisms related to nutrient removal

In this study, the effect of soluble microbial products (SMP) on the metabolisms related to phosphate or nitrogen removal of activated sludge was investigated. Two anaerobic-aerobic activated sludge processes were operated, one with a hydraulic retention time (HRT) of 48 h (RunL) and the other 6.4 h (RunS). The longer HRT of RunL was intended to promote the accumulation of SMPs in the supernatant. With the sludge from RunS and the supernatant from both of the runs, supernatant exchange batch experiments (SEBEs) were conducted, in which the acetate uptake rate and phosphate release rates under anaerobic conditions and the phosphate uptake rate under aerobic conditions were measured as these metabolisms are related to enhanced biological phosphorus removal. The nitrification rate was also measured. The statistical analyses of the results from the SEBEs showed that the supernatant from RunL had an inhibitory effect on the anaerobic acetate uptake and nitrification of the sludge from RunS. The cause of which was attributed to SMPs in the supernatant from RunL. As a result, the inhibitory effect of SMPs on nitrification and anaerobic acetate uptake was confirmed.