由粉煤灰和硫铁矿烧渣制备聚硅酸铁铝混凝剂

研究了以粉煤灰和硫铁矿烧渣为原料制备高效混凝剂聚硅酸铁铝(PSAF)的方法,确定了合理的生产工艺和操作条件。用该混凝剂处理工业废水,并与聚合硫酸铁(PFS)的处理效果比较,结果表明,出水COD和色度去除率分别提高约25%和28%,SS去除率提高约10%。     

双氰胺脱色剂强化混凝处理印染废水

将双氰胺脱色剂与聚合氯化铝进行复配,对某印染厂的二级处理出水进行强化混凝试验,确定了最佳的混凝剂复配比及混凝条件。研究结果表明:混凝剂的最佳复配比为双氰胺脱色剂0.12 mL/L、PAC 87.5 mg/L,此时脱色率达74%,CODCr去除率达57%,UV254去除率达36%,该复合混凝剂的处理效果良好。     

粉煤灰基混凝剂吸附处理垃圾渗滤液中铬离子的研究

利用粉煤灰和废旧铝皮在一定条件下反应,制得粉煤灰基混凝剂,并用于处理垃圾渗滤液中的铬离子。试验结果表明,粉煤灰基混凝剂对垃圾渗滤液中的铬离子有较好的去除效果。在最佳条件下,粉煤灰基混凝剂对垃圾渗滤液中铬离子的去除率达96.3%,比普通粉煤灰的去除率提高了70.4%。     

新型复合混凝剂在染料废水处理中的应用

染料废水由于色度高、水质变化大、生化性差等特点,是当前工业废水处理的难点和焦点之一,混凝法是处理染料废水的主要方法之一。本实验采用矿渣、盐酸和硫酸铁、氧化铝研制了一种新型复合混凝剂,以此来处理直接耐晒大红染料废水。采用单因素法分别通过改变废水pH值,混凝的时间以及混凝剂的投加量来观察混凝剂对废水的处理效果。实验结果表明,随着pH值、混凝剂投加量和反应时间的增加,COD及色度都呈现先降低后趋于稳定的变化趋势：当pH值=11时,色度去除率达最大值84.0%,COD去除率达76.1%;当投加量为0.7g时,色度去除率达最大为88.1%,COD去除率为73.2%;当混凝时间为3min时,色度去除率最大为89.3%,COD去除率达76.2%。综上,此混凝剂的最佳反应条件为投加量0.7g,pH值11,混凝时间3min。该新型复合混凝剂处理染料废水效果好,产生的絮体大,沉降速度快,出水清澈透明。     

混凝法处理珠海某织带厂印染废水

实验研究了用投加化学混凝剂处理印染废水的方法,探讨了不同的混凝剂、混凝剂的投放量和废水的起始pH对COD和色度去除率的影响.研究表明,化学混凝法处理印染废水经济,操作简单,处理效果较好.同时,研究结果表明,KAl(SO4)2投加量为250 mg/L,pH为6.7时处理该废水效果较好.在最优化条件下,COD的去除率为81.6%,脱色率为86.5%.     

强化预处理乙醇废水协同除磷试验研究

酿造行业废水具有高有机物浓度、高浊、高磷等特点,对后续生物处理的十分不利。采用混凝沉淀强化处理,能够有效提高化学需氧量（COD）、悬浮物（SS）的去除率,同时降低磷浓度,对后续生物处理具有促进作用。探讨了不同混凝剂、混凝剂的投加量对混凝沉降速度和COD、浊度、磷去除效果的影响。研究表明,三氯化铁为预处理乙醇废水最佳混凝剂,在p H值为7-8时,投加量为80mg/L,沉降速度较快,COD的去除率可达59%,磷的去除率〉90%。继续投加助凝剂聚丙烯酰胺（PAM）可以提高废水的处理效果,但是不显著。     

混凝法处理制革综合废水的研究

采用不同的混凝剂处理制革综合废水,考察它们对制革废水的混凝效果.实验结果表明:将ZnCl2、ZnSO4分别与PAM按一定比例复合所得A、B型复合混凝剂,混凝效果优于其他混凝剂.通过正交试验,确定了A、B型复合混凝剂的最佳工艺条件,并推荐使用B型混凝剂.在其最佳工艺条件下,处理后的废水COD去除率为71.9%,硫离子去除率为42.0%,明显减轻了下一工序的处理负担.     

强化混凝去除味精生产废水反渗透浓水有机物的研究

对强化混凝工艺处理味精生产废水反渗透浓水中的有机物进行了试验研究,考察混凝剂种类、投加量和反应pH对COD去除效果的影响;试验表明,聚合硫酸铁(PFS)混凝剂在投加量为1.5 g/L、pH为7.0时,COD去除率最高为28.3%;FeCl_3混凝剂在投加量为2.0 g/L、pH为7.0时,COD去除率最高为37.2%;复配混凝剂在投加量1.0 g/L、pH为4.2时,COD去除率最高为31.6%;相同条件下的混凝去除COD效果:FeCl_3混凝剂PFS混凝剂≈复配混凝剂。     

混凝-微气泡气浮法预处理油田采出废液

为了同时去除某油田三元采出液中的浊度和油分,采用混凝-微气泡气浮工艺进行预处理。拟从常用的混凝剂中确定经济高效的混凝剂和适宜的混凝条件。结果表明,聚氯化铝(PAC)混凝剂在碱性条件下,对油田采出废液的处理效果较好。通过探讨混凝剂添加量、气浮处理时间和微气泡发生器工作压力对混凝-微气泡气浮效果影响,获得了较适宜的工艺条件,即PAC添加量50 mg/L,混凝气浮处理15 min,工作压力0.4 MPa,此时浊度去除率和油分去除率分别为46.1%和82.2%。混凝-微气泡气浮的油分去除率比单独混凝沉降和单独微气泡气浮处理的油分去除率之和高出27.7个百分点,说明混凝和微气泡气浮2者之间存在着协同作用,可减少混凝剂的用量。     

污泥回流强化混凝处理印染废水二沉池出水

为了有效提高混凝效率和印染废水出水水质,对常州市某工业园集中印染废水处理厂的二沉池出水进行了深度处理,通过投加无机高分子聚合混凝剂,同时回流二沉池污泥增加水样悬浮物浓度强化去除污染物质,研究中考察了混凝剂投加量、悬浮物浓度及PAM投加量对水样CODCr、色度、SS的去除效果影响.研究结果表明在悬浮物浓度40 mg/L、双酸铝铁投药量0.36 g/L时混凝效果达到最优,此时二沉池出水CODCr去除率为50％较原厂现有工艺处理效果提高了20％～30％、SS去除率为92.5％较原厂现有工艺处理效果提高了50％～60％、色度去除率为72.65％.此外强化混凝技术与传统混凝工艺相比减少了混凝剂和助凝剂的投药量,具有良好的社会效益和经济效益.     

复合混凝法对凉果废水的处理

通过调整复合混凝剂优化处理工艺处理凉果废水,研究凉果废水的处理效果。通过数据分析可以得出结论:采用聚合硫酸铁、聚铝复合混凝剂,其适宜的用量为300 mg/L。凉果废水经过复合混凝处理,其糖及盐分去除率分别高达98.3%、99.7%,COD去除率和脱色率去除率分别为99.6%、96.9%,均达到《污水综合排放标准》(GB8978-1996)的一级标准。     

电絮凝气浮法处理分散艳蓝E-4R废水的研究

采用电絮凝气浮法处理分散艳蓝E-4R染料废水,考察了电解时间、废水初始浓度、pH值及外加电解质氯化钠和絮凝剂等不同反应条件对废水处理效果的影响。结果表明,染料废水脱色率随着电解时间的加大而逐渐增大并随初始浓度的增大而慢慢降低;pH值在2.5~10范围内电解均可获得较高的脱色率。初始浓度为400 mg/L的染料废水,电解20 min后脱色率即达87.39%,但TOC去除率只有10.49%。投加50 mg/L氯化钠后,脱色率和TOC去除率分别达到93.61%和73.49%,TOC去除率提高60%以上。在电解的条件下投加不同絮凝剂能提高染料废水的处理效果,其处理效果从大到小依次为:硫酸铝>三氯化铝>硫酸亚铁,它们的适宜用量分别为50,100,100 mg/L。     

马铃薯淀粉废水的混凝预处理研究

本文介绍了用PAC（聚合氯化铝）、PFS（聚合硫酸铁）、PAM（聚丙烯酰胺）等絮凝剂处理高浓度有机淀粉废水的效果。通过对废水处理前后CODcr值的比较,结果得知PAC作为马铃薯淀粉废水的混凝剂最为合适,PAC的最佳投药量为500mg／L,对废水的CODcr去除率可达到44％左右。再经超滤膜分离,CODcr去除率可达到77％。     

混凝工艺对给水厂滤池反冲洗废水的净化效果

通过实验室杯罐试验,对水厂滤池反冲洗废水的混凝沉淀处理进行了研究.分别采用硫酸铝、聚合氯化铝和三氯化铁为混凝剂,在不同混凝剂投量下的对色度、浊度、CODMn、及UV254的去除效果进行了考察.试验结果表明,对浊度和色度的去除,最佳混凝剂为聚合氯化铝PAC,而对其有机物的去除三氯化铁则最佳.按除浊要求得到的最佳混凝剂投量但不能满足对有机物的去除,所以选择哪种混凝剂及投加量应根据对反冲洗废水的处理要求等综合慎重考虑.     

粉煤灰混凝剂预处理DDNP废水的研究

采用自制粉煤灰混凝剂对DDNP废水进行预处理试验,通过色度去除率和CODCr去除率考察了混凝剂投加量、废水pH值及反应温度等因素对处理效果的影响,用正交试验优化了工艺条件。结果表明当废水pH=9,混凝剂投加量为40g/L,温度为30℃时,处理后废水的CODCr可降低54%以上,色度可降低90%以上。     

Treatment of tannery wastewater by chemical coagulation

The objective of this study was to develop a treatment system that can effectively reduce the concentration of pollutants in tannery wastewater to environmentally acceptable levels and that can greatly reduce the cost of discharging the effluents. Aluminium sulphate and ferric chloride were used as a coagulant in the process. The influence of pH and coagulant dosages on the coagulation process was studied and conditions were optimised corresponding to the best removal of organic matters, suspended solids as well as chromium. The COD and chromium were removed mainly through coagulation: 38-46% removal of suspended solids, 30-37% removal of total COD from settled tannery wastewaters and 74-99% removal of chromium at an initial concentration of 12 mg/l can be achieved by using the optimum coagulant dosage (800 mg/l) in the optimum pH range (around 7.5). Ferric chloride produced better results than aluminium sulphate. The initial chromium concentrations and pH values of the wastewater had a great effect on chromium removal efficiency. Low chromium concentrations and high pH produced a more effective result on chromium removal than high chromium concentrations and low pH. Higher dosages did not significantly increase pollutant removal and were not economical. Coagulation combined with centrifugation improved the removal efficiency of suspended solids (70%). A high degree of clarification is attained as indicated by an excess of 85-86% colour removal. The results provide useful information for tannery wastewater treatment.     

Sequencing coagulation–photodegradation treatment of Malachite Green dye and textile wastewater through ZnO micro/nanoflowers

Sequencing coagulation–photodegradation over ZnO micro/nanoflowers was assessed for Malachite Green (MG) dye removal and followed by the MG-containing textile wastewater treatment. The ZnO micro/nanoflowers were prepared using a facile reflux route and analyzed by various characterization techniques. The flower-like morphological structures of ZnO were witnessed through microscopy analyses. X-ray diffraction findings showed that the prepared ZnO samples were highly crystalline with hexagonal wurtzite structure. The operational parameters including type of coagulant, coagulant dosage, solution pH, photocatalyst dosage and light power exerted their individual influences on the removal of MG dye. The CaCO₃ was the best coagulant among the three coagulants tested due to its high formation of precipitates and adsorption of cationic dye molecules. Using CaCO₃ as a coagulant, 88.3% MG removal was obtained at coagulant dosage of 160?mg and solution pH of 9.0. Complete removal of MG was found with 0.5?g?L^?1 ZnO micro/nanoflowers and 105?W light power. The kinetic analysis showed that a Langmuir?Hinshelwood model was in good agreement with dye removal data. Moreover, a complete removal of MG dye and 80.0% of chemical oxygen demand removal over sequencing coagulation–photodegradation were observed for MG-containing textile wastewater treatment. The sequencing coagulation–photodegradation process using ZnO micro/nanoflowers indicated much promise to be an attractive method for textile effluent treatment applications.     

Olive Mill and Winery Wastewaters Pre-Treatment by Coagulation with Chitosan

The pre-treatment of both winery wastewater (WW) and olive mill wastewater (OMW) by coagulation, using a natural organic coagulant, was investigated as a possible alternative to conventional metal based coagulants, in order to produce a potentially reusable organic sludge. Chitosan was chosen as a model natural organic coagulant and the coagulation process was optimized investigating different coagulant doses and pH values. In spite of the notably lower polluting load for the WW compared to the OMW, the efficiency of the chitosan coagulation was found to be high in terms of total suspended solids (81% and 80% for OMW and WW respectively) and turbidity (94% and 92% for OMW and WW respectively) removal for both wastewaters, but a notable difference was observed in terms of organic matter removal (32% and 73% in terms of COD for OMW and WW respectively). Taking into account that the best performances of the coagulation process by chitosan were achieved at the actual pH for OMW as well as no significant differences were observed for WW as the pH was changed, no chemicals addition is required to adjust pH.