Feasibility Study on the Treatment of Wastewater Containing High-concentration Hg by Coagulation Sedimentation-Adsorption

For the wastewater containing high-concentration Hg,the feasibility of high-concentration Hg in wastewater treated by coagulation sedimentation,adsorption and the combined process was studied. Research results showed that if using the single coagulation sedimentation process,when FeSO_4·7H_2O dosage was 1. 39 g / L,and NaOH dosage was 0. 40 g / L,it could meet discharge requirement,but the reagent cost was 13. 1yuan / t,which was high. Because that there was subsequent adsorption process,it was selected 0. 28 g / L of FeSO_4·7H_2O and 0. 36 g / L of NaOH,and the estimated reagent cost was 2. 62 yuan / t. In selection process of adsorption materials,powdered activated carbon,granular activated carbon and diatomite all could effectively adsorb Hg,and the technology was feasible. When using the combined process of coagulation sedimentation + adsorption to treat the wastewater containing high-concentration Hg( 800 μg / L),removal rate could reach 99%,and operation cost was 2. 71 yuan. It could meet the requirement of sewage discharged into sewer( 20 μg / L) at the technology,and was acceptable at the economy.Therefore,treatment of wastewater containing high-concentration Hg by the combined process was feasible at the aspects of technology and economy.

Treatment of Wastewater from Dairy Farm by Coagulation Sedimentation

In order to evaluate the processing efficiency of coagulation sedimentation on wastewater from dairy farm and to provide reference for wastewater treat- ment, an experimental study was carried out to investigate effects of coagulant dosage, types, pH, dosage of coagulant aids PAM on removal rate of COD, turbidity and SS in wastewater from dairy farm. The results showed that PAC displayed higher effectiveness in treatment; the removal rates of COD, turbidity and SS were 61.4%, 86.6% and 94.5% respectively when pH was 11.0, PAC dosage was 150 mg/L, and PAM dosage was 4 mg/L. The results indicated that coagulation sedimentation could reduce organic content of wastewater effectively and alleviate the load of subsequent biochemical treatment.

Effects of Coagulation and Ozonation Pretreatments on Biochemical Treatment of Fluid Catalytic Cracking Wastewater

Fluid catalytic cracking (FCC) salty wastewaters, containing quaternary ammonium compounds (QACs), are very difficult to treat by biochemical process. Anoxic/oxic (A/O) biochemical system, based on nitrification and denitrification reactions, was used to assess their possible biodegradation. Because of the negative effects of high salt concentration (3%), heavy metals and toxic organic matter on microorganisms’ activities, some techniques consisting of dilution, coagulation and flocculation, and ozonation pretreatments, were gradually tested to evaluate chemical oxygen demand (COD), ammonia-nitrogen (ammonia-N) and total nitrogen (TN) removal rates. In this process of FCC wastewater, starting with university-domesticated sludge, the ammonia-N and TN removal rates were worst. However, when using domesticated SBR’s sludge and operating with five-fold daily diluted influent (thus reducing salt concentration), the ammonia-N removal reached about 57% while the TN removal rate was less than 37% meaning an amelioration of the nitrification process. However, by reducing the dilution factors, these results were inflected after some days of operation, with ammonia-N removal decreasing and TN barely removed meaning a poor nitrification. Even by reducing heavy metals concentration with coagulation/flocculation process, the results never changed. Thereafter, by using ozonation pre-treatment to degrade the detected organic matter of di-tert-butylphenol and certain isoparaffins, COD, ammonia-N and TN removal rates reached 92%, 62% and 61%, respectively. These results showed that the activities of the microorganisms were increased, thus indicating a net denitrification and nitrification reactions improvement.

Test Research on the Treatment of Rectifier Diode Production Wastewater from a Company

Rectifier diode production wastewater that contains acid,alkali and heavy metal ions in a company was treated by using neutralization/coagulation sedimentation method.Firstly,pH of wastewater was adjusted via neutralization reaction,and then heavy metal ions(Cu^(2+),Cr^(2+)and Pb^(2+))were removed by adding coagulant PAC and flocculant PAM.Different acid-alkali neutralization reactions were conducted under the process condition to analyze and compare their neutralization effects.The results showed that removal rates of heavy metal ions were high after coagulation test:Cu^(2+),Pb^(2+)and Cr^(2+)contents dropped from 13.230,0.032,and 1.720mg/L to 0.3,0.001,and 0.24mg/L;besides,total iron,total manganese and turbidity all had very good removal effects.

臭氧氧化+A/O+臭氧氧化工艺在化工园区污水处理厂中的运用

化工园区废水成分复杂,难降解物质多。某化工园区污水处理厂选用分质强化混凝沉淀+臭氧氧化作为预处理工艺,同时采用水解酸化+厌氧好氧(Anaerobic/Oxic,A/O)的二级处理工艺和混凝沉淀+臭氧氧化的深度处理工艺。实际运行结果表明,该组合工艺对化学需氧量(Chemical Oxygen Demand,COD)的平均去除率为85.7%,COD去除效果良好,出水水质优于《城镇污水处理厂污染物排放标准》(GB 18918—2002)的一级A标准。

光伏企业生产废水处理工程实例

根据光伏企业生产废水水质特征,按照分类收集、分质处理原则,将含氟废水经混凝沉淀预处理后再与综合废水合并,采用电催化-混凝沉淀-管式微滤-UASB-AO组合工艺进行处理。运行结果表明,该工艺对光伏企业综合废水中的污染物有较高的去除率,对F^(-)、COD_(Cr)、BOD_(5)、NH_(4)^(+)-N、TN和SS的最终去除率分别达到了89.1%、97.6%、96.5%、90.6%、84.3%和85.3%,出水水质可以达到《电池工业污染物排放标准》(GB 30484—2013)表2新建企业水污染物间接排放标准要求,工程投资共计797万元,运行费用为8.36元/t,通过沼气回收、磁悬浮风机节能技术,每年产生经济效益为34.0万元,为光伏企业生产废水的设计与运行处理提供参考。

“混凝沉淀+A/O+芬顿反应”处理卡拉胶生产废水

为解决AO(厌氧+好氧)工艺处理卡拉胶废水难达标的问题,针对卡拉胶生产过程中产生大量含藻类颗粒的废液富含盐碱和有机物的特点,采用混凝沉淀去除富盐碱的混合溶液,然后用厌氧、好氧生化处理工艺+芬顿反应池处理去盐碱的有机废液。经过一年期的运行结果表明:该工艺的最终出水pH值都落在6-9、色度为15-20度、CODcr、排放质量浓度为55-68 mg/L,出水质量达到《中华人民共和国污水综合排放标准》(GB8978-1996)一级排放标准。该工艺的整体效果好,可为卡拉胶生产企业提供参考借鉴。

混凝沉淀法处理冶金含氟废水工艺研究

水中氟含量超标会对环境造成巨大影响,目前冶金行业普遍采用混凝沉淀法处理含氟废水。因此,针对混凝沉淀法除氟工艺中影响因素多、除氟效果缺少综合评估的问题,以某钢铁公司生产过程中产生的含氟废水为对象进行研究。首先通过正交实验考察pH、聚氯化铝(PAC)投加量、聚丙烯酰胺(PAM)投加量、PAC搅拌时间、PAM搅拌时间对含氟废水除氟效率影响的主次关系。研究结果表明,影响除氟效率的主次因素排序依次为pH、PAC搅拌时间、PAC投加量、PAM搅拌时间、PAM投加量。此外,对上述因素及温度等单因素变化对除氟效率的影响进行了研究。结果表明,最佳条件:pH为7、PAC投加量为70 mL、PAM投加量为2.5 mL、PAC搅拌时间为15 min、PAM搅拌时间为30 min、温度为30℃,在此最佳条件下除氟效率最高,可以达到99.3%。实际工程应用中,混凝沉淀法对氟离子总去除率在80%~90%,出水氟含量保持在7 mg/L左右,能够满足氟离子达标排放的要求。

污水中阴离子表面活性剂的影响及去除

文章系统研究了应用较为广泛的阴离子表面活性剂——十二烷基苯磺酸钠(SDBS)对生物池中污染物(氨氮、总磷、硝态氮)的去除影响以及不同混凝剂[聚合氯化铝(PAC)、硫酸铝(AS)、聚合硫酸铁(PFS)、三氯化铁(FeCl_(3))]对SDBS去除效能和最佳投加位点的选择。试验结果表明,氨氮和总磷的去除率随着SDBS浓度的增加会明显降低,SDBS对以上两种污染物的去除有显著的抑制作用,而SDBS对硝态氮的去除基本无影响。通过进一步试验得出,FeCl_(3)作为混凝剂可以更有效去除SDBS,当FeCl_(3)与SDBS在最佳质量配比(3∶1)时,SDBS的去除率可达到78.3%。在提升泵站、初沉池出口、外回流液中投加FeCl_(3)对SDBS皆有明显的去除效果,但在初沉池出水中投加时SDBS的去除效果最佳。

“A/RPIR+磁混凝沉淀”组合工艺处理城镇废水的稳定运行效能分析

“A/RPIR+磁混凝沉淀”组合工艺具有运行能耗低,投资节省,占地少,运行稳定,出水水质好等优势,已在河道黑臭水体治理及市政污水处理领域得到广泛应用。本文对某市政污水处理厂(A/RPIR+磁混凝沉淀工艺、设计规模10×10^(4)m^(3)/d)的稳定运行效能进行分析评估。结果表明,水厂出水水质全部稳定达标,年平均吨水电耗为0.196kWh,产出泥饼含水率相对稳定,平均为79.5%,日泥饼产量为74.1 t,污泥产率为1.14×10^(4)TDS/m^(3)。污水厂整体运行效能良好。

物化预处理-生化组合工艺处理草甘膦生产废水工程实例

对不同工艺废水采用物化方法分质预处理后,利用厌氧-缺氧-CAST组合工艺处理综合废水,设计处理量为470 m^(3)/d。运行实践表明:中和反应-混凝沉淀对总磷的去除率可以达到46%,整个工艺处理出水COD稳定低于500 mg/L,总磷稳定低于8 mg/L,出水水质达到接管要求。

宜昌市某园区难降解工业废水深度处理试验及改造工程设计

工业园区难降解工业废水的经济性达标一直是亟待解决的难题。宜昌市某工业园区污水处理厂主要处理造纸厂及食品加工厂预处理后的难降解工业废水,长期存在出水不达标、运行成本高的难题。研究以现状污水处理厂难降解有机污染物为研究对象,开展了活性炭静态吸附、混凝沉淀和类芬顿催化氧化对比试验研究,比较了3种方法的处理效果。结果表明,在pH值=5.0~5.5时,类芬顿催化氧化工艺对CODCr的总体去除率最高可达73%以上,出水水质可稳定达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A排放标准,新增运行成本为0.905元/m^(3)。基于深度处理对比试验结果,针对该污水处理厂用地紧张的现状,结合现有土地及各构筑物单元布置情况,提出了提标改造方案,可为类似高比例工业污水厂升级改造提供参考借鉴。

两级化学-混凝沉淀工艺处理高浓度含氟废水工程实例

针对某从事硅砂开采、加工、提纯企业排放的高浓度含氟废水,文中采用两级化学-混凝沉淀组合工艺,在投加钙盐的基础上联合投加适量PAC和PAM。工程实践结果表明,在系统稳定运行的情况下,出水可稳定满足回用及排放要求,回用水氟离子浓度小于20 mg/L,排水氟离子浓度小于10 mg/L,且联合药剂投加可提高氟化物的去除率。

矿井废水处理中混凝沉淀过滤技术应用

矿井废水经过处理后可作为煤矿工业用水,提高水资源利用价值,减轻废水排放引起的环境污染问题。本文以某煤矿项目为例,通过对矿井水来源及水质特点的了解,提出混凝沉淀过滤技术在矿井废水处理中的应用策略,监测污染物排放指标,并从经济效益和生态环境效益进行分析,认为混凝沉淀过滤技术的综合应用效果良好,具有推广价值。

EBIS(改良AO)+磁混凝工艺在陕西某城市污水厂提标改造工程中的应用

陕西某城市污水处理厂总设计规模80000 m^(3)/d,其中40000 m^(3)/d生化池利用现状的CASS池进行改造,另外新建40000 m^(3)/d生化池及80000 m^(3)/d规模的深度处理设施。污水处理厂进水主要来源为城市生活污水,混合少量的工业污水,处理工艺采用“预处理+EBSI生化池+磁混凝沉淀池+次氯酸钠消毒”主体工艺,介绍了工程的工艺流程、主要设计参数及运行效果等。出水水质监测指标表明,本项目出水完全满足《陕西省黄河流域污水综合排放标准》(DB61/224-2018)中A标准。

聚合氯化铝-聚丙烯酰胺处理含氟废水研究

使用聚合氯化铝(PAC)-聚丙烯酰胺(PAM)联合处理含氟废水,考察了PAC投加量、PAM浓度、pH值、反应时间以及搅拌速度对除氟效果的影响。结果表明,在PAC投加量4400 mg/L、PAM浓度1 mg/L、溶液pH值7.0、反应时间20 min、搅拌速度300 r/min时,氟去除率达97.98%,除氟后溶液中氟离子残余浓度为0.81 mg/L。溶液中杂质离子的存在会降低PAC的除氟性能。

磁介质混凝沉淀工艺在污水处理厂深度除磷改造中的应用

重庆市某污水处理厂现状规模为7.5万m^(3)/d,采用改良型氧化沟+滤布滤池处理工艺,出厂尾水达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。由于面临水体国控断面水质稳定达标的考核,工程在利用厂区有限用地的条件下,新增磁介质混凝沉淀工艺以提升处理效率。运行结果表明:污水处理厂整体出水效果提升,在90%覆盖率条件下,出水TP质量浓度为0.10 mg/L,SS质量浓度为4 mg/L,COD_(Cr)质量浓度为14 mg/L,BOD5质量浓度为2.3 mg/L,TN质量浓度为11.2 mg/L,氨氮质量浓度为0.30 mg/L,出水稳定达到准Ⅳ类标准。项目建设投资指标为468元/m^(3);运行药耗分别为:PAC(10%溶液)投加量为98 mg/L;PAM(阴离子)投加量为0.95 mg/L;磁粉的补充量为1.73 mg/L;电耗为0.021 kW·h/m^(3)。磁介质混凝沉淀工艺直接运行成本为0.111 0元/m^(3),主要成本为药剂,占比为85.41%。

医药产业园区废水处理工程实例

针对山东某医药产业园区生产废水高COD、高氨氮、高盐分和可生化性差等特点,设计采用蒸氨-MVR蒸发结晶-臭氧催化氧化-A^(2)/O-深度处理工艺,处理水量为500 m^(3)/d。工程实践表明,该工艺对COD、氨氮、总氮、总磷和SS的去除率分别达到了97.1%、89.9%、85.9%、93.5%和96.3%,相应出水水质分别为358、27、52、0.62和40 mg/L,出水水质满足GB/T 31962—2015《污水排入城镇下水道水质标准》中的A级排放标准。

PCB生产废水处理工程实例

针对太湖流域某大型PCB生产企业排放的综合有机废水含有胺类、有机盐类、有机溶剂等特征污染物,采用了水解酸化-缺氧反硝化-好氧生化-辐流式沉淀池的组合工艺进行处理。经过调试投产运营后,在进水COD、氨氮、TN质量浓度分别为1200~1800、110~140、130~170 mg/L时,出水质量浓度分别为30~45、3.0~5.0、11~14 mg/L,出水TP质量浓度稳定在0.5 mg/L以下,相应去除率分别为97.5%、97.1%、91.7%、99%,出水水质稳定达到GB 18918—2002《城镇污水处理厂污染物排放标准》中的一级A标准。工程总投资3300万元,运维成本约为1.34元/t。

IC厌氧-两级AO工艺处理白酒废水工程实例

针对白酒废水中有机物含量高、可生化性较好、色度高、悬浮物浓度高等特点,某企业设计采用IC厌氧-两级AO-深度处理组合工艺进行处理,工程运行结果表明,在综合废水进水ρ(COD_(Cr))≤11750 mg/L、ρ(BOD_(5))≤5875 mg/L、ρ(NH_(3)-N)≤60 mg/L,处理后出水ρ(COD_(Cr))≤30 mg/L、ρ(BOD_(5))≤6 mg/L、ρ(NH_(3)-N)≤1.5 mg/L,满足GB 3838—2002《地表水环境质量标准》中Ⅳ类标准要求,其他指标满足GB/T 18920—2020《城市污水再生利用城市杂用水水质》中城市绿化及道路清扫水质要求。