化学同步除磷药剂的优选研究

以城市污水为处理对象,通过分析三氯化铁、硫酸亚铁、三氯化铝、聚合氯化铝、聚合硅酸硫酸铁等5种常用混凝剂的同步除磷效果,优选化学同步除磷药剂种类。结果表明,硫酸亚铁的同步除磷效果最佳,在进水TP为2.75 mg/L的条件下,按Fe/TP=1.2(铁与进水TP的物质的量之比)投加硫酸亚铁,可使出水TP降至0.5 mg/L以下,满足GB 18918—2002的一级A标准。在选择硫酸亚铁作为同步除磷药剂的条件下,当Fe/TP≤1.6时,Fe/TP值与出水TP和PO34-浓度均呈现较好的相关性。     

南宁市埌东污水厂提标改造的化学除磷研究

为将南宁市埌东污水处理厂二级出水TP浓度从一级B提升至一级A标准,对该厂出水进行了化学除磷研究。以硫酸铝、聚合氯化铝(PAC)、聚合硫酸铁(PFS)、氯化铁和聚合氯化铝铁(PAFC)为药剂对出水进行化学除磷混凝剂选择试验,并对混凝剂用量进行优化,同时考察了温度对PAC化学除磷的影响。结果表明,各药剂除磷效果排序为:硫酸铝=PFS氯化铁PACPAFC;综合除磷效果及药剂成本,确定PAC为适宜混凝剂;为控制出水TP≤0.5 mg/L,PAC适宜用量为23 mg/L,污水处理药剂成本为0.016元/m3;在10~30℃范围内,温度对PAC除磷效果影响较小。此外,PAC对污水中COD、BOD5、NH+4-N也有一定的去除作用。     

化学除磷药剂的比较试验

针对水体富营养化的问题,指出排放污水中的磷是引起水体富营养化的主要诱因,选用了几种水处理中常用的化学药剂,通过对比试验,探讨了其间的除磷效果,试验表明,聚合氯化铝和三氯化铁具有较好的除磷性能.     

气浮工艺用于海水淡化预处理试验研究

以三氯化铁和聚合氯化铝作为混凝剂,氯水作为氧化剂,考察了气浮工艺用于海水淡化预处理的运行效果.结果表明:预氧化可以强化混凝+气浮预处理工艺对浊度、CODMn、UV254和TOC的去除效果,三氯化铁的最佳投加量为15～20 mg/L,聚合氯化铝最佳授加量为6～10mg/L,最佳气浮回流比为15％;在最佳运行条件下,预处理...     

厌氧前置氧化沟化学除磷投药点的优化

厌氧前置氧化沟工艺辅助化学除磷具有很好的脱氮除磷效果,不同的投药位置会影响出水水质和最佳投药量。以新兴县污水处理厂一期工程为研究对象,探讨了不同投药位置对出水水质及最佳投药量的影响,并对其进行了优化改造。结果表明:采用缺氧池和氧化沟出水口两点位加药比氧化沟出水口单点位加药方式更能提高聚合氯化铝(PAC)化学除磷效率,降低整个生物处理单元的磷负荷,节约药剂用量,取得了更好的除磷效果。     

化学沉淀法去除水中镍的研究

试验在自来水为原水的条件下,调节不同的pH,分别进行了三氯化铁、聚合氯化铝和硫化钠去除重金属镍效果的研究.结果表明三氯化铁药剂对水中镍的去处效果明显,能将污染浓度为国家标准限值50倍的镍去除到国家标准限值以内.聚合氯化铝药剂对水中镍的去除能力有限,仅能将污染浓度为国家标准限值10倍的镍去除到国家标准限值以内.三氯化铁的...     

化学沉淀法对水中钛、钒金属污染物的应急处理技术研究

通过对钛、钒金属污染物进行化学沉淀法混凝试验,研究了其可行性、最佳处理条件及最大应对能力。结果表明,用三氯化铁和聚合氯化铝作混凝剂均对钛有很好的去除效果,且混凝沉淀后上清液pH对钛的去除效果并无影响;在钛标准限值10倍、50倍、100倍高浓度条件下,混凝沉淀后上清液钛浓度依然远低于其标准限值,去除率达99.9%以上;混凝前将水样调至合适的pH值,采用三氯化铁和聚合氯化铝均可有效去除钒,但总体上来说,采用三氯化铁作混凝剂的去除效果要明显优于聚合氯化铝;在钒标准限值10倍、50倍、100倍高浓度条件下,三氯化铁和聚合氯化铝作混凝剂,随着污染物浓度的增大,其去除率均呈显著下降趋势,混凝沉淀后上清液钒浓度均无法达标。     

铁盐与铝盐混凝去除反渗透浓水中磷元素的研究

反渗透(RO)工艺在污水回用处理中应用广泛,但反渗透浓水中污染物含量非常高,以活性污泥处理法为代表的污水处理工艺并不能有效去除其中的磷.混凝作为一种常规的水处理工艺,常被用在污水深度处理中.以反渗透浓水为研究对象,模拟污水处理厂实际运行工况,考察了高效除磷剂、氯化铁、硫酸铁、聚合氯化铝、硫酸铝等5种混凝剂的混凝除磷效果...     

化学沉淀法去除水中钼的特性研究

采用自来水为原水,考察了不同pH值条件下三氯化铁、聚合氯化铝对重金属钼的去除效果.结果表明,原水pH值为7.5时,投加15 mg/L三氯化铁能将原水中标准限值100倍(7mg/L)的钼去除到0.07mg/L以下;聚合氯化铝对钼的去除效果较差,对原水中标准限值5倍的钼的最高去除率仅为11%;三氯化铁对钼的去除效果明显优于...     

城市污水处理化学辅助除磷药剂的筛选

针对某污水处理厂经过缺氧滤池+两级曝气生物滤池处理方法对总磷的去除率低这一问题,对硫酸亚铁、三氯化铁等六种混凝剂的除磷效果进行了研究,并通过经济比较,确定了硫酸亚铁为最佳的除磷混凝剂。     

天津市某县高色度地下水处理试验研究

针对天津市某县地下水低浊高色的特点,应用强化混凝工艺对该地下水进行了处理,强化混凝烧杯试验表明：聚合氯化铁对该地下水的色度去除率高,强化混凝过程的最优条件是：混凝剂投加量15mg／L;静沉时间30min;300r／min搅拌1min,70r／min搅拌15min。     

Chemical coagulation of combined sewer overflow: heavy metal removal and treatment optimization

The coagulation of combined sewer overflow (CSO) was investigated by jar-testing with two commercial coagulants, a ferric chloride solution (CLARFER) and a polyaluminium chloride (WAC HB). CSO samples were collected as a function of time during various wet-weather events from the inlet of Boudonville retention basin, Nancy, France. Jar-tests showed that an efficient turbidity removal can be achieved with both coagulants, though lower optimum dosages and higher re-stabilization concentrations were obtained with the aluminum-based coagulant. Optimum turbidity removal also yielded effective heavy metal elimination. However, the evolution with coagulant dosage of Cu, Zn, Pb, Cr, soluble and suspended solids contents followed various patterns. The removal behaviors can be explained by a selective aggregation of heavy metal carriers present in CSO and a specific interaction between hydrolyzed coagulant species and soluble metals. Stoichiometric relationships were established between optimal coagulant concentration, range of optimal dosing, and CSO conductivity, thus providing useful guidelines to adjust the coagulant demand during the course of CSO events.     

PAC和PAM复合混凝剂处理垃圾渗滤液的研究

通过投加混凝剂聚合氯化铝(PAC)和助凝剂聚丙烯酰胺(PAM)对垃圾渗滤液进行混凝沉淀处理,根据单因素和正交试验确定其最佳工艺条件.结果表明,混凝的最佳条件:PAC投加量为750 mg/L、PAM投加量为15 mg/L、快速(150 r/min)搅拌1 min、中速(45 r/min)搅拌6min、慢速(35 r/min)搅拌7 min、在快速混合之后投加助凝剂.在该处理条件下,系统对垃圾渗滤液中COD和浊度的去除率达到最大,分别为27.45%和65.80%.     

Return sludge employed in enhancement of color removal in the integrally industrial wastewater treatment plant

In this study, the recirculation of chemical sludge and integrated sludge were employed for enhancement of color removal in an integrally industrial wastewater treatment plant. The jar test was conducted for simulating chemical coagulation process with different coagulants, aluminum sulfate and polyaluminum chloride (PACl), after different activated sludge systems (with air or high-purity oxygen). The results showed that with sludge recirculation the process of coagulation for the color removal has up to 35% enhancement in comparison with no sludge recirculation. Meanwhile, the color removal enhancement of coagulant aluminum sulfate was approximately 2 to 3-times the color removal enhancement of coagulant PACl at the optimum ratio of return sludge. In coagulation process with influent color of 1220 true color unit (TCU), the optimum dosage of return sludge was 3010mg/L, when coagulant PACl or aluminum sulfate was employed. In coagulation process with influent color of 536 TCU, the optimum dosages of return sludge were 2340 and 4680mg/L using PACl and aluminum sulfate, respectively.     

复合混凝剂PTA-CPAM的形貌结构与净水性能

以聚合氯化铝(PAC)、四氯化钛(TiCl_4)、阳离子聚丙烯酰胺(CPAM)为原料成功制备无机-有机复合混凝剂聚钛氯化铝-阳离子聚丙烯酰胺(PTA-CPAM),采用红外光谱(IR)、扫描电镜(SEM)、能谱分析(EDS)与差热热重(TG-DTA)对产物的结构、组成及热稳定性进行分析。此外,对PTA-CPAM的混凝性能进行研究。结果表明:当m(CPAM)/m(PTA)=0.4、PTA-CPAM投加量为9.0mg/L、pH为9.0的条件下,混凝剂的净水效果最优,且PTA-CPAM对不同初始浊度的水样都有较优的除浊能力;协同增效作用使PTA-CPAM具备更强的吸附电中和与吸附架桥网捕能力,表现出优异的除浊性能。     

Nutrient removal and sludge production in the coagulation-flocculation process

Nutrient removal and sludge production in the coagulation-flocculation process, applied to a slaughterhouse effluent, have been studied. Fe2(SO4)3, Al2(SO4)3 and polyaluminium chloride were used as coagulants. Inorganic products were used as coagulant aids: activated silica, powdered activated carbon and precipitated calcium carbonate and synthetic polyelectrolytes: cationic polyacrylamide, polyacrilic acid, anionic polyacrylamide and polyvinyl alcohol. Performances were measured under optimum conditions for the products used. They were found after studying the different variables which influence the process. Phosphorus removal is very high (approximately 100% for the orthophosphate and between 98.93% and 99.90% for the total phosphorus). Ammonia nitrogen removal is very low although appreciable performances are observed for albuminoid nitrogen (73.9-88.77%). The use of coagulant aids reduces the volume of the sludge produced up to 41.6%.     

饮用水中溴化物的混凝去除及影响因素研究

在饮用水的消毒过程中，溴化物可与消毒剂反应生成具有“三致”效应的消毒副产物。为此，选择AlCl3作混凝剂，研究了混凝去除溴化物的效果及影响因素。结果表明，向模拟水样（溴化物初始浓度为0．2mg／L）中投加3-15mg／L的AlCl3，当无腐殖酸存在时对溴化物的去除率为93．3％-99．2％，当有腐殖酸存在时对溴化物的去除率为78．4％～98．4％；对于湘江原水。投加15mg／L的AlCl3时对溴化物的去除率为87．0％。在低混凝剂投量或高pH值条件下，腐殖酸的存在明显降低了对溴化物的去除率；在高混凝剂投量或低pH值条件下，腐殖酸对去除溴化物的影响较小。因此，可采用强化混凝去除饮用水中的溴化物。     

Optimization of the coagulation-flocculation process for pulp mill wastewater treatment using a combination of uniform design and response surface methodology

Pulp mill wastewater was treated using the coagulation-flocculation process with aluminum chloride as the coagulant and a modified natural polymer, starch-g-PAM-g-PDMC [polyacrylamide and poly (2-methacryloyloxyethyl) trimethyl ammonium chloride], as the flocculant. A novel approach with a combination of response surface methodology (RSM) and uniform design (UD) was employed to evaluate the effects and interactions of three main influential factors, coagulant dosage, flocculant dosage and pH, on the treatment efficiency in terms of the supernatant turbidity and lignin removals as well as the water recovery. The optimal conditions obtained from the compromise of the three desirable responses, supernatant turbidity removal, lignin removal and water recovery efficiency, were as follows: coagulant dosage of 871 mg/L, flocculant dosage of 22.3 mg/L and pH 8.35. Confirmation experiments demonstrated that such a combination of the UD and RSM is a powerful and useful approach for optimizing the coagulation-flocculation process for the pulp mill wastewater treatment.     

铝盐一级强化处理城市污水的正交试验

为研究一级强化处理城市污水的最佳工艺条件和各种因素对处理效果的影响,采用Al2(SO4)3和PAC分别与非离子、阴离子、弱阳离子的高分子助凝剂配合,进行了6种药剂组合的正交试验。结果表明,混凝剂投量是出水水质最主要的影响因素,在优化条件下,一级强化工艺对COD的去除率达到60%,出水COD为150mg/L左右;对TP的去除率由铝盐混凝剂的投量决定,出水TP<1mg/L,并可随混凝剂投量的继续增加而降低。高分子助凝剂能有效提高Al2(SO4)3的除磷效果,是影响出水TP的第二重要因素,但PAC系列是影响出水TP最小的因素。总之,Al2(SO4)3 高分子助凝剂与PAC 高分子助凝剂两个系列对COD的去除效果差别不大;但是,Al2(SO4)3 高分子助凝剂系列除磷效果更好。     

Comparison of coagulation behavior and floc structure characteristic of different polyferric-cationic polymer dual-coagulants in humic acid solution

Three polyferric-cationic polymer dual-coagulants were comparatively evaluated in terms of coagulation behavior and floc structure characteristic in the coagulation of humic acid (HA) solution. The first dual-coagulant, PFC-PDADMAC, was prepared by premixing of polyferric chloride (PFC) and polydiallyldimethylammonium (PDADMAC) before dosing. The other two were achieved by dosing PFC and PDADMAC in different order. For the given neutral condition, all three dual-coagulants gave similar HA removal before reaching optimal dosage. The strongest charge neutralization and narrowest effective coagulation dosage range were obtained when PFC was dosed firstly. While the weakest charge neutralization and the broadest effective coagulation dosage were obtained when PDADMAC was used as the primary coagulant. The HA removal of all three dual-coagulants was slightly pH dependent for optimum coagulant doses. Fe(III) hydrolysis species distributions of the dual-coagulants in coagulation process were measured by ferron method. PFC-PDADMAC gave the highest content of active Fe(III) coagulating species which is responsible for the coagulation performance of ferric coagulant. The evolution of floc size and floc fractal dimension (D_f) in coagulation process was measured under optimum dose and neutral condition by laser diffraction instrument and small-angle laser light scattering (SALLS), respectively. All three dual-coagulants gave similar final floc size but different floc growth rate and floc structure. Both the growth rate and D_f were in the same order: PFC dosed firstly > PDADMAC dosed firstly > PFC-PDADMAC.