化学生物絮凝工艺污泥回流对污染物的絮凝效果研究

采用化学生物絮凝(CBF)工艺处理上海市城市污水,通过停止加药试验、不同污泥回流比模拟试验、污泥胞外聚合物组分及含量的分析测定,研究分析污泥回流对污染物去除效果的影响.结果表明,CBF的回流污泥具有较强的污染物去除能力,其携带的化学药剂可以增强系统抗磷酸盐冲击负荷能力,停止PAFC药剂投加期间,其COD去除率基本维持在50%以上, PO3-4、TP去除率呈现逐渐缓慢下降的趋势.化学药剂投加是CBF实现良好泥水分离效果的重要因素.CEPT工艺剩余污泥VSS中的EPS含量仅为17.24 mg/g,而CBF工艺VSS中的EPS含量高达145.89 mg/g,其微生物活性较高,生物絮凝能力较强.化学强化一级工艺(CEPT)剩余污泥中药剂的絮凝性能较差,其对TP和COD的去除能力随污泥回流比提高而显著降低,而由于存在生物絮凝作用,CBF系统的污泥具有较强的絮凝性能.化学生物絮凝工艺是一种化学与生物协同作用的污水强化一级处理工艺.     

化学生物絮凝工艺污染物去除试验研究

化学生物絮凝污水处理工艺是一种新的一级强化处理工艺。该工艺在传统的化学混凝的基础上将沉淀池内的污泥回流至化学生物絮凝池,利用化学混凝和污泥吸附的协同作用去除污水中的污染物。中试试验结果表明,聚合硫酸铝铁絮凝剂投加量为70mg/L,PAM投加量为0.5m g/L时,COD、TP和SS去除率分别为61.8%、74.5%和74.6%。化学生物絮凝池内污泥富集了未反应的絮凝剂,这部分絮凝剂对污水中TP具有很好的去除作用。化学生物絮凝池内污染物的沿程分析显示,回流污泥与污水充分接触可促进TP的进一步去除。     

新型硫酸铝-壳聚糖助滤剂强化砂滤效能研究

将硫酸铝和壳聚糖复配作为微絮凝助滤剂（AS-CTS）,考察其强化过滤性能.利用分子量分级、荧光光谱等手段分析有机物的去除特性,通过Zeta电位、絮体粒径、分形维数的变化分析其强化过滤机理.结果表明：AS-CTS较AS、CTS强化过滤效果明显,在AS/CTS复配比为2：1、CTS投加量0.3mg/L,转速300r/min,搅拌时间2min的条件下,砂滤出水浊度能达到0.1NTU、颗粒物125个/mL,残余铝浓度0.02mg/L;浊度和颗粒物去除率较未加AS-CTS分别提高了58%、61.7%.AS-CTS强化过滤可有效去除分子量>30KDa的腐殖酸和1~3KDa间的色氨酸类蛋白、溶解性微生物代谢产物、类富里酸.AS-CTS主要靠高分子吸附架桥作用和界面化学作用,增加胶体颗粒在滤料表面的粘附;通过形成较大粒径和分形维数的微絮体,增强絮体向滤料表面的迁移.     

聚合铝基复合絮凝剂用于城市纳污河道废水处理

以城市纳污河道废水为处理对象,聚合氯化铝-二甲基二烯丙基氯化铵（PAC-PDMDAAC,代号JYF-1）复合絮凝剂为处理药剂,在室内模拟化学强化一级处理（CEPT）现场工艺,进行了烧杯絮凝实验,主要考察废水中颗粒物、有机物和氮磷的去除效果,以及pH和表面负荷率（SOR）对絮凝效果的影响,分析了投药前后废水中颗粒物粒径分布和电荷特性的变化,讨论了JYF-1药剂的作用机理及其在CEPT工艺中的应用. 结果表明,聚合铝基复合絮凝剂JYF-1比传统的PAC拥有更好的絮凝效果,对pH和SOR的适应能力更强. JYF-1对非溶解性污染物的去除要好于溶解性污染物的去除,8 mg·L^-1的JYF-1对COD和溶解性COD（SCOD）的去除率分别为76.72%和64.31%,处理后出水的可生化性大幅提高,BOD/COD从处理前的0.23增加到处理后的0.53. JYF-1具有良好的除磷效果和一定的脱氮效果,当JYF-1投量为12 mg·L^-1时,溶解性总磷（STP）的去除率可达到90%以上,总磷（TP）的去除率可达到80%左右,总氮（TN）去除率为20%左右. 将JYF-1应用于CEPT工艺,可以无需改变现有的设备和工艺,以更少的投药量获得更好的出水水质,产生更少的污泥,是值得推广应用的高效低价絮凝剂.     

HCA强化混凝预处理生活污水的效能及机理

通过单因素及正交试验,以聚二甲基二烯丙基氯化铵（HCA）为混凝剂对模拟农村生活污水进行强化混凝预处理,考察了影响HCA混凝去除SS、TP及有机物的主要因素及其主次顺序,并以Zeta电位及分形维数对HCA的混凝机理进行了分析.结果表明,影响HCA处理效果的因素顺序为初始pH值值 > HCA投加量 > 絮凝搅拌时间 > 混合搅拌速度梯度 > 混合搅拌时间 > 絮凝搅拌速度梯度,在优化条件下HCA混凝对SS、TP及COD去除率最高分别达94.1%、74.9%及61.1%;当HCA投加量为15mg/L时,Zeta电位与絮体分形维数分别为-2.03mv及1.0149.试验表明HCA对生活污水具有较好的处理效果,强化混凝去除污染物的机理主要是电性中和作用.     

生物吸附强化一级处理中添加蛭石填料的试验

实验研究了蛭石填料在生物吸附强化一级处理中的作用，并对处理工艺的影响因素进行了分析。试验结果表明，投加蛭石填料后，不影响系统对有机物及悬浮颗粒物的去除。生物絮凝吸附在30min时达到最大，污泥再生曝气时间以2h较适合。应用了蛭石填料的处理系统的氨氮去除性能得到显著提高，氨氮的去除率比对照组高30％以上。     

投加HCPA对UF-MBR处理低温高色高氨氮水源水效能与膜污染控制的影响

采用高浓度纯化凹凸棒土-超滤膜生物反应器(HCPA-UF-MBR)耦合工艺处理低温高色高氨氮水源水,考察HCPA对UF-MBR系统除污效能与膜污染控制的影响.基于污泥混合液粒径分布、Zeta电位、有机物相对分子质量分布、傅里叶红外光谱与三维荧光光谱分析探究HCPA投加后UF-MBR中污泥混合液性能的变化,研究清洗前后膜的微观性貌、洗脱液的物质成分,明确HCPA在减缓膜污染方面发挥的作用.结果表明:HCPA-UF-MBR工艺对色度、COD_(Mn)、TOC、NH_4~+-N、浊度等的去除效果优于UF-MBR工艺的1.02~3.9倍,HCPA-UF-MBR中TMP始终大于UF-MBR.投加HCPA后,UF-MBR内污泥絮体平均粒径变小、趋于均匀,易使膜通量降低,HCPA通过吸附、生物载体降解有机物与降低污泥混合液粘度作用控制膜污染,使系统除污效能未降返增;污泥混合液的|Zeta|电位降低11%~26%,利于污泥沉降;系统对UF膜难以截留的3~10kD小分子有机物的去除效能增强,污泥混合液与相应膜表面滤饼层中有机物种类与含量明显减少,系统对蛋白质类、溶解性微生物代谢产物去除效果显著.膜表面主要污染物为无机物Ca、Fe、Mg、Mn、Si与有机物,同样运行条件下膜HCPA-UF-MBR的污染程度比膜UF-MBR轻,污染物少;污染膜HCPA-UF-MBR表面的有机物易被水清洗但效果甚微,碱清洗膜效果最佳;该研究为凹凸棒土在MBR中的应用提供技术支撑.     

微絮凝强化过滤工艺处理低温低浊水的实验研究

以北京市某水厂冬季沉后水为研究对象,分别采用常规过滤工艺和强化过滤工艺对其进行处理.通过改变聚合氯化铝(PACl)投加量、滤料粒径d和微絮凝时间,并结合水头损失、颗粒数、总有机碳(TOC)、化学需氧量(COD)等实验数据,对低温低浊水体强化过滤工艺条件进行了研究.结果表明,强化过滤工艺与常规过滤工艺相比具有较强的除浊、去除有机物和颗粒物的能力,当微絮凝时间为2min时可以得到较好的过滤效果;PACl投药量为1.5mg·L-1时,浊度可降到0.04NTU,而常规过滤工艺最多只能将浊度降到0.2NTU.在滤料选用方面,当滤料粒径d=0.6～1.2mm时滤后水中颗粒数(2～5μm)、浊度、COD等指标均达到最优值.同时,电感耦合等离子体光谱(ICP-OES)检测结果表明,滤后水中Al3+含量小于0.2mg·L-1,并未因二次投加PACl而升高,因此,不会对水的饮用产生任何健康和安全风险.     

山地城市排水管网特细颗粒物特性及变化规律

对山地城市排水管网中特细颗粒物的粒径分布特征及变化规律、Zeta电位分布特征及变化规律和ρ(SS)的变化规律进行研究,同时对相关水化学参数(如电导率、pH)的变化规律进行了分析.结果表明:特细颗粒物的平均粒径、Zeta电位、ρ(SS)和电导率分别为21.04～73.53μm、-20.83～-11.15 mV、106～492 mg/L和973～2 445μS/cm,其统计平均值分别为(43.74±14.12)μm、(-17.95±1.88)mV、(233±90)mg/L和(1 343±331)μS/cm;pH为7.25～7.63.工业废水的排入对排水管网特细颗粒物的粒径分布特征、Zeta电位分布特征以及电导率有显著的影响并呈现出一定的规律性;传统沉砂池对进水中特细颗粒物的去除能力相当有限,特细颗粒物会直接进入生物处理系统.      

颗粒活性炭对AnDMBR污水处理性能与动态膜性质的影响

构建了颗粒活性炭(GAC)强化型厌氧动态膜生物反应器(AnDMBR),考察了GAC投加量(3,6,10,20 g/L)对工艺的过滤性能、污染物去除、产甲烷性能以及动态膜性质的影响,探究了GAC的物化和生物强化作用。研究结果表明,与未投加GAC相比,随着投加GAC浓度的增大,浊度去除率分别提高了3.1～12.3百分点,COD去除率分别提高了5.7～12.1百分点,GAC投加量越大对污染物去除的贡献越大。与未投加GAC相比,随着投加GAC浓度的增大,甲烷总产率分别提高了23.7%、34.6%、24.2%、8.3%,最佳GAC投加量为6 g/L。投加GAC改善了AnDMBR的污染物去除性能和产甲烷性能。GAC的投加有利于降低厌氧污泥和动态膜中EPS的含量,削减出水中荧光性溶解性有机物的含量,减小跨膜压差(TMP)的增长率。同时GAC的吸附与生物富集效应可形成生物活性炭,增大污泥粒径,改善污泥性质和动态膜的多孔结构,对AnDMBR的长期运行起到了积极作用。     

Particle size distribution and removal in the chemical-biological flocculation process

The particle characterization from the influent and effluent of a chemical-biological flocculation (CBF) process was studied with a laser diffraction device. Water samples from a chemically enhanced primary treatment (CEPT) process and a primary sediment tank process were also analyzed for comparison. The results showed that CBF process was not only effective for both the big size particles and small size particles removal, but also the best particle removal process in the three processes. The results also indicated that CBF process was superior to CEPT process in the heavy metals removal. The high and non-selective removal for heavy metals might be closely related to its strong ability to eliminate small particles. Samples from different locations in CBF reactors showed that small particles were easier to aggregate into big ones and those disrupted flocs could properly flocculate again along CBF reactor because of the biological flocculation.     

Particle size distribution and removal by a chemical-biological flocculation process

The particle characterization from the influent and effluent of a chemical-biological flocculation （CBF） process was studied with a laser diffraction device. Water samples from a chemically enhanced primary treatment （CEPT） process and a primary sediment tank process were also analyzed for comparison. The results showed that CBF process was not only effective for both the big size particles and small size particles removal, but also the best particle removal process in the three processes. The results also indicated that CBF process was superior to CEPT process in the heavy metals removal. The high and non-selective removal for heavy metals might be closely related to its strong ability to eliminate small particles. Samples from different locations in CBF reactors showed that small particles were easier to aggregate into big ones and those disrupted flocs could properly flocculate again along CBF reactor because of the biological flocculation.     

Removal and transformation of organic matters in domestic wastewater during lab-scale chemically enhanced primary treatment and a trickling filter treatment

To find a simple and economical way for treating the domestic wastewater in small counties and towns, a process combining chemically enhanced primary treatment and a trickling filter (CEPT-TF, representing the physical and biological effects) was constructed and operated in laboratory conditions. The characteristic behaviors of dissolved organic matter in raw wastewater and effluents were examined during steady-state operation. Experimental results showed that the process of CEPT and TF in series was beneficial for the removal of hydrophobic and hydrophilic organics. Specially, the hydrophobic and aromatic materials could be preferentially removed in the CEPT unit, and the hydrophilic fraction in the TF. Structural changes of the organic fractions during the operation of the different units were also characterized via spectrum analysis.     

Dyes wastewater treatment by reduction-oxidation process in an electrochemical reactor packed with natural manganese mineral

A novel technology which combined electrochemical process catalyzed by manganese mineral with electro-assisted coagulation process was proposed in this study. The mineralization of organic pollutant from simulated dye wastewater containing an azo dye Acid Red B（ARB） was experimentally investigated using this method. It was found that the manganese mineral could catalyze the electrochemical process dramatically. The TOC removal percentage of electrochemical treatment catalyzed by manganese mineral was 43.6% while the TOC removal percentage of the process using the manganese mineral alone and using the electrolysis alone were 9.3% and 20.8%, respectively. Moreover, it was found that combined electroxidation with electro-assisted coagulation process could more effectively eliminate ARB. After a period of 180 min electrooxidation and 300 min electroreduction, almost 66.9% of TOC was removed, and the dissolved Mn^2＋. could be effectivly removed. The effects of the order of oxidation and reduction, the proper ratio electrooxidation/reduction time, and current density on the removal efficiency were investigated in detail. In addition, a proposed mechanism of manganese-mineral-catalyzed electrooxidation-reduction process was discussed in this paper.     

铁盐和铝盐混凝对水中天然有机物的去除特性研究

以三氯化铁和硫酸铝为研究对象,探讨了2种混凝剂对水中天然有机物的去除效果及特点.结果表明,低投量下,硫酸铝对天然有机物的去除效果要好于三氯化铁,混凝剂投量高于15mg/L时,三氯化铁的效果较好.如混凝剂投量为10mg/L时,硫酸铝和三氯化铁处理水的TOC分别为4.19mg/L和9mg/L;当混凝剂投量为20mg/L时, TOC分别降至2.44mg/L和1.69mg/L.三氯化铁混凝后水的pH值降低幅度高于硫酸铝,形成的水解产物所带正电荷密度升高,水中有机物的质子化程度高,有利于对有机物的吸附去除.通过对UV254出和SUVA的考察可知,三氯化铁对共轭结构及不饱和有机物的去除能力要高于硫酸铝.2种混凝剂对水中不同性质有机物的去除效果不同,三氯化铁对亲水性有机物去除效果较好,对小分子量有机物去除高于硫酸铝,如混凝剂投量为20mg/L时,三氯化铁和硫酸铝对相对分子质量区间小于10 000的有机物去除率分别为16.4%和6.1%,而硫酸铝对大分子量有机物去除效率较高.     

A field study of advanced municipal wastewater treatment technology for artificial groundwater recharge

Field studies were conducted to investigate the advanced treatment of the municipal secondary effluent and a subsequent artificial groundwater recharge at Gaobeidian Wastewater Treatment Plant, Beijing. To improve the secondary effluent quality, the combined process of powdered activated carbon adsorption, flocculation and rapid sand filtration was applied, which could remove about 400 dissolved organic carbon （DOC） and 70% adsorbable organic halogens. The results of liquid size exclusion chromatography indicate that in the adsorption unit the removed organic fraction was mainly low molecular weight compounds. The fractions removed by the flocculation unit were polysaccharides and high molecular weight compounds. The retention of water in summer in the open recharge basins resulted in a growth of algae. Consequently, DOC increased in the polysaccharide and high molecular weight humic substances fraction. The majority of the DOC removal during soil passage took place in the unsaturated area. A limited reduction of DOC was observed in the aquifer zone.     

高DOM渗滤液厌氧-好氧-混凝处理工艺

采用厌氧-好氧-混凝工艺,对垃圾焚烧厂高DOM渗滤液进行处理,当进水ρ(COD_Cr)平均值为10 800 mg/L时,出水ρ(COD_Cr)平均值可达208 mg/L;同时,着重针对各工艺单元出水DOM不同分子质量分布区间的ρ(COD_Cr)以及DOM组成成分的变化进行了研究.结果表明:该处理工艺对DOM分子质量＜50 ku的有机物去除率均可达到94.7%以上,而对分子质量＜2 ku的有机物的去除率可达99.0%;对渗滤液DOM组成成分〔腐殖酸(HA)、富里酸(FA)和亲水性有机质(HyI)〕的去除率均达到90.0%以上,表明该组合工艺用于处理垃圾焚烧厂渗滤液是可行的.