硫酸铝投加量对前置A^2/O除磷及活性污泥性能的影响

为保证城镇污水厂出水总磷达标排放,以A^2/O工艺为研究对象,采用生物除磷与前置化学除磷相耦合的方法,重点考察Al_2(SO_4)_3投加量对出水TP含量以及反应器内活性污泥性能的影响。结果表明,铝、磷摩尔比为1:1时,出水COD和TP、NH4^+-N、TN含量均达到了GB 18918-2002的一级A标准;铝、磷摩尔比为0.5:1时,出水TP的质量浓度则高达2.0 mg/L左右。铝、磷摩尔比为1:1时,好氧污泥SVI由投药前的87.4 m L/g降至74.2 m L/g,ζ电位由-4.73 m V降至-7.16 m V,氧吸收速率由3.185 mg/(g·min)升到3.462 mg/(g·min),胞外聚合物(EPS)的总量由66.25mg/g升到105.2 mg/g,蛋白质与多糖的质量比由5.23降至2.09,表明污泥活性、沉降性能、脱水性能增强。进行好氧污泥微生物群落结构分析,发现铝、磷摩尔比为1:1时微生物种属由投药前8种减为5种,微生物丰度降低,拟杆菌和绿弯菌的比例有所上升,与变形菌一起成为反应器内优势菌群。

氨氮冲击对活性污泥性能影响的研究

氨氮是炼油催化剂生产废水达标排放的一项重要指标,通常采用生化处理法对其进行有效控制。由于系统中活性污泥承受氨氮负荷冲击的能力较弱,易发生膨胀、中毒等情况,而且催化剂生产废水中其浓度变化范围较大,不可避免要对活性污泥的性能产生较大的影响。本文分别在污泥起始浓度为1500,2000,2500mg/L时提高进水氨氮浓度(保持其他条件不变)对污泥系统进行冲击试验,旨在研究氨氮冲击对活性污泥性能的影响,并观察了氨氮冲击下微生物相的演变过程。

化学协同除磷对城市污水处理厂活性污泥性能的影响

化学协同除磷在提高污水处理厂除磷效果的同时,存在除磷剂过量投加导致剩余污泥产量增加及影响活性污泥脱氮除磷性能等问题。目前化学除磷剂实际投加率多为理论投加率的2-3倍甚至更高,由于污水处理厂的除磷要求及除磷剂投加策略不同将影响除磷剂过量投加程度。因此,本文分析了化学协同除磷过量投加除磷剂对污水处理系统活性污泥性能影响。

溶菌酶辅助壳聚糖调理对活性污泥脱水性能的影响及其机理

通过测定真空抽滤泥饼含水率、污泥比阻、污泥ζ电位,研究溶菌酶辅助壳聚糖调理对活性污泥脱水性能的影响,并通过提取污泥絮体形态学特征进行二维分形维数(D2)分析,深入剖析污泥脱水机理。结果表明,溶菌酶辅助壳聚糖调理后泥饼含水率下降了约21.3%,污泥比阻下降了约94.5%,活性污泥脱水性能得到显著提高。分析调理前后的污泥ζ电位和絮体形态,发现污泥双电层被压缩,污泥|ζ|电位降至0.28 mV,同时污泥絮体密实程度增加,D2值提高到1.748,说明溶菌酶辅助壳聚糖调理活性污泥可以促进污泥胶体的脱稳、絮凝,压缩絮体颗粒间孔隙并释放部分间隙水。

磺胺和四环素类抗生素对活性污泥性能的影响

废水处理工艺中抗生素类污染物的存在可能会对生物处理过程产生长期而深远的影响,为探明此类污染物对废水生物处理主体活性污泥性能等方面的影响,采用间歇培养法研究了活性污泥法处理污水时,抗生素类污染物的存在对活性污泥性能如胞外聚合物(EPS)、污染物处理能力、脱氢酶活性和群落结构的影响。结果表明,抗生素的存在会导致活性污泥的胞外聚合物总量及其主要组分蛋白质和多糖增加,以产生保护屏障;且由于污泥絮体解体,细胞破裂导致EPS中DNA和色氨酸含量增加。同时,由于蛋白质大量增加引起的表面负电荷的增加,使污泥疏水性增强,絮凝性能恶化;污泥絮体解体导致污泥颗粒变小,SVI也随之下降;在活性污泥脱氢酶活性急剧下降的同时,出水TOC迅速升高。此外,抗生素类污染物在抑制活性污泥中大部分细菌的同时,对部分菌群也有刺激生长作用,最终导致活性污泥生物群落结构的改变。四环素类抗生素对活性污泥的EPS和絮凝沉降性能的影响大于磺胺类,而对污水处理能力和群落结构的影响则不如磺胺类。抗生素类污染物的长期存在会对活性污泥沉降性能、絮凝性能、脱氢酶活性以及活性污泥群落结构等产生一系列负面影响,进而影响污染物去除效果,导致出水水质恶化。

全细胞脂肪酶(菌)对SBR系统中活性污泥性能的影响

将全细胞脂肪酶(菌)以产脂肪酶微生物的形式直接投加到SBR内,与投加野生型酵母菌及空白对照进行比较,研究其对活性污泥性能及含油脂废水处理效果的影响。结果表明,在15～20℃,pH 6.5～7.5,进水油脂浓度2 000 mg/L的条件下,投加一定量全细胞脂肪酶(菌)的SBR系统间歇处理4 d,活性污泥增殖速度加快,是投加野生型酵母菌的1.3倍。静置30 min时活性污泥SV达到45%,SVI为151,MLSS最高可达2 965 mg/L左右,絮凝时间缩短且无污泥膨胀现象。投加全细胞脂肪酶(菌)的SBR系统中,油脂去除率为86.5%,COD去除率为79.5%,与投加野生型酵母菌的SBR系统相比去除率提高了1.3倍。说明投加全细胞脂肪酶(菌)后活性污泥性能增强,油脂废水处理效率提高。

同步化学除磷对A^2/O工艺除污染效能与活性污泥性能的影响

考察了A2/O同步化学除磷工艺中Al2(SO4)3投加量对TP、COD、NH+4-N和TN的去除率与活性污泥性能的影响。结果表明,常温(18~32℃)条件下同步化学除磷最适宜的Al2(SO4)3投加量为铝、磷摩尔比0.5∶1,此条件下出水TP、COD、NH+4-N和TN浓度均能达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A标准。研究同时发现,Al2(SO4)3投加后,活性污泥的沉降性能和污泥活性均有所增强,其中SVI值由93.8 m L·g-1降至81.3 m L·g-1,Zeta电位由-5.5 m V降至-11.8 m V,胞外聚合物EPS含量增加了59.9%,蛋白质与多糖的比例由5.2降至2.1,比耗氧速率由4.2 mg·(g·min)-1升高到6.7 mg·(g·min)-1(以MLSS计)。微生物菌群结构分析结果表明,投药后污泥中微生物种类由投药前的8种减少为6种,硝化菌和反硝化菌比例有所降低,聚磷菌比例升高为6%。在低温(0~10℃)条件下,Al2(SO4)3投加量需有所增加,当铝、磷摩尔比为1∶1时,反应器出水TP、COD、TN和NH+4-N浓度方可达到一级A标准。

不同曝气强度下活性污泥中松散束缚型胞外聚合物组分含量及其对污泥沉降性能的影响

为了探求曝气强度对活性污泥沉降性能的影响规律和机制,在实验室条件下利用序批式活性污泥法(SBR)装置研究了活性污泥好氧阶段曝气强度对活性污泥沉降性能、松散束缚型胞外聚合物(LB-EPS)含量及其组分的影响。结果表明:(1)随着曝气强度增加,活性污泥中LB-EPS含量逐渐升高。(2)活性污泥LB-EPS中,蛋白质为其最主要成分,其次为多糖,腐殖酸所占比例最小,多糖含量及比例均随曝气强度的上升而增大,蛋白质和腐殖酸含量受曝气强度影响不大。(3)曝气强度为40、80、120L/h,污泥体积指数(SVI)分别为(65.00±0.98)、(83.00±1.45)、(103.00±2.00)mL/g。曝气强度增加引起活性污泥沉降性能的恶化的原因主要在于曝气强度的增加会使LB-EPS中的多糖含量上升。

制药废水中三乙胺对活性污泥特性、氨氮及COD的影响

目的:探究制药废水中的三乙胺对活性污泥特性、氨氮、化学需氧量(COD)的影响。方法:向活性污泥系统中加入不同浓度三乙胺,并检测活性污泥化学需氧量(COD)、氨氮去除率、活性污泥特性及污泥表观产率系数(Y_(obs))。结果:随着三乙胺浓度的增大,氨氮浓度显著升高,氨氮去除率呈现下降趋势;在进水三乙胺浓度为0~100 mg/L条件下,活性污泥COD及去除率受到的影响较小;当三乙胺浓度为100 mg/L时,SV_(30)、SVI迅速上升至58.1%和160 mL/g,MLSS、MLVSS迅速下降。结论:采用生物法处理制药废水,需对其三乙胺浓度进行控制。

菲律宾蛤仔黏附污泥用于废水处理的生物絮凝剂特性研究

菲律宾蛤仔黏附污泥已被报道为一种新型的天然生物絮凝剂,适合淡水处理和海水处理。本文探究了菲律宾蛤仔黏附污泥在实际废水处理中的应用效果。结果表明:菲律宾蛤仔黏附污泥作为絮凝剂可以有效去除废水中悬浮物(SS),去除率可达49.3%,并能有效改善膨胀的活性污泥的沉降性能,促进光合细菌的挂膜,促进率为33.3%;另外,其还有效吸附去除水中的重金属,当重金属离子Cd^(2+)、Zn^(2+)、Cu^(2+)的浓度分别为5.09 mg/L、14.09 mg/L、255.81 mg/L时,去除率分别达72%、67%、92%。

Influence of Pyrolytic Biochar on Settleability and Denitrification of Activated Sludge Process

Biochar is a massively produced by-product of biomass pyrolysis to obtain renewable energy and has not been fully used. Incomplete separation of sludge and effluent and insufficient denitrification of sewage are two of main factors that influence the efficiency of activated sludge process. In this work, we proposed a new utilization of biochar and investigated the effect of biochar addition on the performance of settleability and denitrification of activated sludge. Results show that the addition of biochar can improve the settleability of activated sludge by changing the physicochemical characteristics of sludge （e.g., flocculating ability, zeta-potential, hydrophobicity, and extracellular polymeric substances constituents）. Moreover, the dissolved organic carbon released from biochar obtained at lower pyrolysis temperature can improve the nitrate removal efficiency to a certain extent.

兼性生化反应池出水的深度处理工艺研究

通过试验分析了兼性生化反应池出水中残余有机污染物的 COD组成 ,指出反应池内兼性活性污泥的生物吸附絮凝性能是反应池在负荷较高时污染物去除效率较低的主要原因。为保证系统出水达标 ,针对兼性系统的出水水质 ,利用化学混凝、好氧生物吸附絮凝和生态渗滤方法进行了 3套后续深度处理工艺方案的试验研究并对其进行了技术经济比较 。

Evaluation and improvement of wastewater treatment plant performance using BioWin

In this study,the activated sludge model implemented in the BioWin software was validated against full-scale wastewater treatment plant data. Only two stoichiometric parameters(Y p /acetic and the heterotrophic yield(Y H)) required calibration. The value 0.42 was used for Yp /acetic in this study,while the default value of the BioWin software is 0.49,making it comparable with the default values of the corresponding parameter(yield of phosphorus release to substrate uptake(YPO4)) used in ASM2,ASM2 d,and ASM3 P,respectively. Three scenarios were evaluated to improve the performance of the wastewater treatment plant,the possibility of wasting sludge from either the aeration tank or the secondary clarifier,the construction of a new oxidation ditch,and the construction of an equalization tank. The results suggest that construction of a new oxidation ditch or an equalization tank for the wastewater treatment plant is not necessary. However,sludge should be wasted from the aeration tank during wet weather to reduce the solids loading of the clarifiers and avoid effluent violations. Therefore,it is recommended that the design of wastewater treatment plants(WWTPs) should include flexibility to operate the plants in various modes. This is helpful in selection of the appropriate operating mode when necessary,resulting in substantial reductions in operating costs.

Ammonium Ion Adsorption and Settleability Improvement Achieved in a Synthetic Zeolite-Amended Activated Sludge

Municipal wastewater treatment plants typically exhibit two classic problems： high ammonium concen- tration in water after conventional biological treatment and, in some cases, poor activated sludge sediment ability. Potential solutions to these problems were investigated by adding a synthetic zeolite obtained from coal fly ash to different steps of activated sludge treatment. The experimental results for ammonium removal fit well with the theoretical adsorption isotherms of the Freundlich model with a maximum adsorption capacity of 13.72 mg.g-＇. Utiliza- tion of this kind of zeolite to improve activated sludge sediment ability is studied for the first time in this work. It is found that the addition of the zeolite （1 g. L-1） to an activated sludge with settling problems significantly enhances its sediment ability and comoact ability. This is confirmed by the sludge volume index （SVI）, which was reduced from 163 ml.g-1 to 70 ml.g-r, the V60 value, which was reduced from 894 ml.L-1 to 427 ml.L-1, and the zeta poten- tial （0, which was reduced from -19.81 mV to -14.29 mV. The results indicate that the addition of this synthetic zeolite to activated sludge, as an additional waste management practice, has a positive impact on both ammonium removal and sludge settleability.

Storage and Subsequent Reactivation of Phosphate-Accumulating Aerobic Granules

Phosphate-accumulating aerobic granules cultivated in a sequencing batch reactor were composed of inner rod-shaped bacteria aggregates and outer twining filamentous bacteria. The influence of two-month storage under dif- ferent conditions on the storage and subsequent reactivation performance of aerobic granules was investigated. After two-month storage the granules sealed at 4 ~C in distilled water or normal saline （named granules A and granules B, respectively） could maintain their characteristics as before, while the granules idled in the reactor at room temperature （named granules C） exhibited decreased properties. During reactivation, granules A and granules B presented almost identical recovery performance, faster than granules C, in terms of phosphorus removal efficiency, mixed liquor sus- pended solids （MLSS）, phosphate release and accumulating ability. The results suggest that hermetical storage at low temperature promoted the maintenance of the granular properties and the reviving behaviors of phosphateaccumulating aerobic granules, and storage medium had little influence on the storage and recovery perfomlance.

Interplay Factors Involved in the Inadequate Performance of Four Activated Sludge Systems in Northern Gauteng-South Africa

A recent study conducted on the four activated systems serving the surrounding communities in the Northern Gauteng revealed the failure of three of these wastewater treatment plants to remove enteric pathogenic bacteria and protozoan parasites such as Cryptosporidium and Giardia spp. To determine the factors involved in the inadequate performance of the plants, the following parameters were considered： the design characteristic of the plants, the microbiological structure and the physical characteristics of the plants. The results revealed that higher than optimal influent loadings and inadequate aeration systems, observed in Baviaanspoort, Refilwe and Rayton Water Care Works （WCW） increased the composition of filamentous bacteria in flocs and decreased the diversity of protozoan species in the sludge. Sequentially, these resulted in the poor settling properties of the sludge at these plants. However, Zeekoegat WCW showed optimum influent loads and adequate aeration systems. This maintained balance in the microbial community, resulting in good clarification of the sludge.

优化恒压死端过滤方法筛选抗膜污染药剂

为研究采用恒压死端过滤方法初选MBR中抗膜污染药剂的可靠性,考察了在搅拌或不同曝气时间条件下,投加不同剂量高分子絮凝剂的活性污泥的静态过滤性能,确定了曝气10min为最佳扰动时间;同时表明,投加高分子絮凝剂可使污泥絮体尺寸增加、Zeta电位升高、上清液中的SMP浓度降低。另外,恒压死端过滤得出的絮凝剂最佳投加量为400 mg/L,这对减缓MBR的膜污染有积极的指导作用。在试验条件下,向MBR中投加400 mg/L的高分子絮凝剂,可使膜污染速率降为对照MBR的74.88%。