淀粉基聚合氯化铝铁复合物的制备及絮凝性能研究

将马铃薯淀粉改性后,与聚合氯化铝铁复合,制备了淀粉基聚合氯化铝铁复合物(PAFC-CMPS)。通过FTIR、TG、SEM等手段对PAFC-CMPS的结构和表面形态进行了表征和分析。将PAFC-CMPS用于淀粉废水的处理,考察了絮凝时间、废水pH、絮凝剂加入量、温度等因素对PAFC-CMPS絮凝性能的影响。最佳实验条件下,絮凝剂对淀粉废水的COD去除率可达77.9%。     

聚合磷硫酸铁对含铜废水絮凝性能的影响

研究了含铜废水絮凝过程中聚合磷硫酸铁的用量、pH值、沉淀时间的影响。结果表明，聚合磷硫酸铁对含铜废水处理效果明显，处理过程中可能会出现聚合磷硫酸铁酸化解聚现象，但是处理后排水中的残留磷量和残留铁量较少，低于国家排放标准，不存在铁、磷的二次污染。     

用还原-絮凝沉淀法处理电镀废水的研究

以绿矾作还原剂、电石渣作中和剂,对还原-絮凝沉淀处理电镀废水的方法进行了研究,探讨了绿矾-电石渣处理含铬废水的工艺条件.试验表明,最佳处理工艺条件为铁铬比20,还原反应的pH值3.0～4.0,还原时间50～60 min,中和反应的pH值8.6～9.2.采用该法按最佳工艺条件对电镀废水进行处理,具有较好的处理效果,处理后的水样中各重金属离子浓度及总铬含量均低于国家排放标准.     

淀粉接枝聚丙烯酰胺在造纸废水中的应用

研究了淀粉接枝聚丙烯酰胺对造纸废水的处理,探讨了絮凝剂的投入量、废水的PH值、絮凝温度和絮凝时间对絮凝效果的影响,并得出了淀粉接枝聚丙烯酰胺作为絮凝剂处理脱墨废水时的最佳絮凝条件:絮凝剂用量为10mL,絮凝温度为40℃,PH值大于9.另外,和聚丙烯酰胺的絮凝效果进行了对比,结果表明:St-PAM的絮凝效果优于PAM的絮凝效果.     

聚季铵盐聚丙烯酰胺对电镀废水中Ni2+的吸附性能研究

在静态条件下,对聚季铵盐聚丙烯酰胺(PQAAM)吸附含Ni2 的电镀废水进行了研究,探讨了PQAAM用量、废水pH值、吸附时间、吸附温度对去除Ni2 效果的影响.结果表明,在废水pH值为6.0～8.0、Ni2 浓度0～100 mg/L范围内,吸附时间为80 min、吸附温度为20℃时,按Ni2 与PQAAM质量比为1∶30投加PQAAM进行处理,Ni2 去除率可达98%以上.含Ni2 电镀废水经PQAMM吸附后,废水中Ni2 的含量低于国家排放标准.     

催化铝内电解法预处理印染废水的试验

本试验以铝作为反应材料,铜作为催化材料构成反应器,预处理印染废水,弥补了催化铁内电解工艺处理强碱度印染废水效果不佳的局限。探讨了铝铜比、反应时间、进水pH值、温度等因素对处理效果的影响,得出了最佳工艺条件。     

粉煤灰制备聚硅酸铝絮凝剂处理洗煤废水研究

以粉煤灰为原料,经高温碱熔、中温酸浸、低温聚合,制备出聚硅酸铝絮凝剂。通过研究各种絮凝剂对洗煤废水的絮凝效果,探索了合成絮凝剂所需的最佳条件为Na2CO3用量按照摩尔比nNa2CO3:nSiO2=0.7:1加入,HCl用量按n:n=4:1投入,絮凝剂聚合阶段pH值控制在3为宜。     

粉煤灰絮凝剂处理高浓度印钞废水的研究

以粉煤灰为原料制备无机絮凝剂,采用酸浸法提取出粉煤灰中的铝及少量铁,再用碱浸出粉煤灰中的硅,然后利用上述提取出的产品制备无机絮凝剂(聚硅酸铝及聚硅酸铝铁),主要研究絮凝剂对印钞废水的浊度和COD的去除情况.结果表明:絮凝剂在介质条件为在中性范围、絮凝时间2天以上、温度为35℃时絮凝效果最佳,去浊度可高达100%,COD去除率可达到80%,达到国家2级排放标准.     

组合技术处理丁苯橡胶废水研究

采用絮凝沉降-芬顿试剂氧化-中和沉降-生化组合技术对丁苯橡胶废水进行了达标处理研究,重点考察了经过絮凝沉降处理后的丁苯橡胶废水用芬顿试剂处理的反应条件。结果显示,丁苯橡胶废水用150mg/L聚合氯化铝及2mg/L的阳离子聚丙烯酰胺絮凝沉降处理后,废水COD去除率为20.1%;芬顿试剂氧化絮凝沉降后的丁苯橡胶废水的最佳条件为pH 3.5,FeSO4·7H2O 3g/L,H2O2 3g/L,1.5h,30℃,反应后的氧化液用氢氧化钙中和沉降处理,芬顿试剂氧化阶段的COD去除率为74.5%;丁苯橡胶废水经絮凝沉降-芬顿试剂氧化-中和沉降处理后,COD去除率为79.6%,TP去除率在98%以上,该水再经过生化处理后,达到排放要求:COD≤50mg/L,TP≤0.5mg/L,NH4-N≤5mg/L。     

用铝盐絮凝剂处理含铬废水的研究

用絮凝剂PAC和PACS处理电镀含铬废水，操作简单，经济适用，最大除铬率可达94％，PACS中因含有SO42-而具有更佳的絮凝效果。     

电解制备高Alb聚合氯化铝的工艺特性研究

开发出一种批量（200kg/d)电解制备高Alb聚合氯化铝的工艺设备，并对其工艺特性进行了研究，确定了电解制备过程中的最佳工艺参数为电解电压1．4V，电流强度600A，研究了电解制备过程中PH、温度、铝含量等相关因素的变化规律并确定了最佳的PH及温度范围，要用此设备可最终制备出Al2O310%,Alb67.6%和碱化度64．5％的高效聚合氯化铝，此设备紧凑，制备方法简单，并可在线调节制备过程中的各种参数，易于实现自动控制，具有很好的应用前景。     

Synthesis of polyamine flocculants and their potential use in treating dye wastewater

Polyamine flocculants were synthesized by the polycondensation of dimethylamine and epichlorohydrin, in which organic amines, e.g. 1,2-diaminoethane, were used as modifying agents. Different products were obtained by varying the reaction parameters, such as the molar ratio of epichlorohydrin to dimethylamine, the amount of 1,2-diaminoethane and reaction temperature. The polyamine flocculants were characterized by transmission electron microscope (TEM). Their flocculation performance was evaluated with simulated dye liquor and actual printing and dyeing wastewater. The behavior of the flocculants was compared with that of inorganic coagulant, polyaluminum chloride (PAC). The experimental results show that polyamine with the highest viscosity and cationicity could be prepared under following conditions: an epichlorohydrin to dimethylamine molar ratio of 1.5, a reaction temperature of 70 degrees C, a 3% content of 1,2-diaminoethane in the total reaction monomers and a reaction time of 7h. Polyamine polymers can, as flocculants for treating simulated and actual dye wastewater, remove color and COD efficiently. The rate of color removal from reactive red liquor, reactive blue liquor and reductive yellow liquor reached as high as 96%, 97% and 96%, respectively. The highest efficiency of color removal and COD removal from polyamine for treating dye wastewater was 90% and 89%, respectively.     

Improvement of paint effluents coagulation using natural and synthetic coagulant aids

The coagulant iron chloride and the flocculants Polysep 3000 (PO), Superfloc A-1820 (SU) and Praestol 2515 TR (PR) have been used in this study to show the efficiency of coagulation flocculation process in the chemical precipitation method for the removal of organic and colouring matters from the paint industry wastewater. This study also includes the amount of produced sludge. The results indicate that FeCl(3) is efficient at pH range 8-9 and at optimal dose of 650 mgl(-1). Iron chloride allows the removal of 82% of chemical oxygen demand (COD) and 94% of colour. However, sequential addition of coagulant and polymeric additives enhance clearly pollutant removal and produces less decanted sludge compared to the results obtained when the coagulant is used alone. The removal efficiency of COD reaches 91% and that of colour 99%. Coagulation-biflocculation process is more effective than the coagulation-monoflocculation one. The sequential addition of iron chloride, Polysep 3000 (cationic flocculant) and Praestol 2515 TR (anionic flocculant) seems to be the most suitable combination for the treatment of the paint industry wastewaters.     

Flocculation behaviour of model textile wastewater treated with a food grade polysaccharide

In this study, the application of a food grade polysaccharide namely Plantago psyllium mucilage has been assessed for the removal of dyes from model textile wastewater containing golden yellow (C.I. Vat Yellow 4) and reactive black (C.I. Reactive Black 5). A series of contact time experiments were conducted to assess the system variables such as concentrations of mucilage and dyes and pH. This mucilage reduces the dye concentration by flocculation and settling. The optimal flocculant concentration required to affect flocculation is independent of dye concentration within the range examined. The dye removal obtained was influenced by the salts concentrations in the wastewater sample. The flocculation efficiency was sensitive to pH when pure aqueous solutions of dyes were used, but it was relatively unaffected by pH change when salts were added to the dye solutions. The experimental results show that the mucilage is more effective for removal of solubilised vat dye than for reactive black.     

Feasibility investigation of oily wastewater treatment by combination of zinc and PAM in coagulation/flocculation

Poly-zinc silicate (PZSS) is a new type of coagulant with cationic polymer synthesized by polysilicic acid and zinc sulfate. It has been used in several sorts of wastewaters treatment, but not used in oily wastewater treatment. In this study, we investigated the coagulation/flocculation of oil and suspended solids in heavy oil wastewater (HOW) by PZSS and anion polyacrylamide (A-PAM). The properties of PZSS cooperated with A-PAM were compared with PAC and PFS in dosages, PAMs amount, settling time, pH value and flocs morphology. The results showed that PZSS was more efficient than PAC and PFS. Under the optimum experimental conditions of coagulation/flocculation (dosage: 100mg/L, A-PAM dosage: 1.0mg/L, settling time time: 40min and pH 6.5-9.5), more than 99% of oil was removed and suspended solid value less than 5mg/L by using PZSS cooperated with A-PAM, which could satisfy the demands of the pre-treatment process for HOW to be reused in the steam boiler or recycled into the injecting well.     

Performance optimization of coagulation/flocculation in the treatment of wastewater from a polyvinyl chloride plant

This paper presents results of an experimental study of coagulation/flocculation process of wastewater generated from a polyvinyl chloride (PVC) plant. The wastewater contains fine chlorine-based solid materials (i.e. latex). Experiments were carried out using a model wastewater which is chemically identical to the actual plant but is more consistent. Inorganic ions (Al2(SO4)3, FeCl3 and CaCl2) and a water soluble commercial polyelectrolyte (PE) were added to the wastewater sample. Coagulation efficiency was determined by measuring both the turbidity of the supernatants and the relative settlement of the flocs in the jar test. It was found that aluminum and ferric ions were more efficient than calcium ions as coagulants. The addition of polyelectrolyte was found to improve substantially the coagulation/flocculation process. It was found that the (Al2(SO4)3) combined with the polyelectrolyte at certain pH and agitation speed gave the best results compared to calcium chloride or ferric chloride when combined with the same concentration of polyelectrolyte. Only 0.0375g of a solution of (0.5% Al2(SO4)3) was required to coagulate the model wastewater. Ferric chloride (2.5% FeCl3) combined with the polyelectrolyte, on the other hand, required 0.1g while the optimum turbidity is almost the same. As for calcium chloride (2.5% CaCl2) it was found to be the least effective. The coagulation/flocculation process was found to be dependent on both pH and the agitation speed.     

Removal of tungsten oxyanions from industrial wastewater by precipitation, coagulation and flocculation processes

Tungsten removal from industrial wastewater by precipitation, coagulation and flocculation processes using ferric chloride is reported. Suitable process conditions (pH, ferric chloride concentration) were established in jar tests performed with wastewater samples. Alkaline wastewater was treated with ferric chloride and pH was adjusted to various points using sulphuric acid. Tungsten removal was found to be most efficient (98-99%) in acidic conditions (pH<6). The process conditions were also found to be suitable for operation of an industrial scale wastewater treatment facility. More than 97% of tungsten were removed and the residual concentration was smaller than 10 ppm.     

Hybrid processes for the treatment of cattle-slaughterhouse wastewater using aluminum and iron electrodes

Electrocoagulation (EC) of cattle-slaughterhouse wastewater, which is characterized by (i) high turbidity (up to 340 Nephelometric turbidity units), (ii) increased chemical oxygen demand (COD) concentration (4200 mg L(-1)), and (iii) a dark color, was investigated with the purpose of lowering the turbidity and COD concentration to levels below the permitted direct-discharge limits. Iron and aluminum were used as electrode materials. Experiments were conducted to evaluate the effects of current density, initial pH, and supporting electrolyte (Na(2)SO(4)) dosage on the performance of the system. COD removal increased with increase in current density. The original pH of wastewater (7.8) was found to be preferable for both the electrode materials. Higher concentrations of Na(2)SO(4) caused an increase in COD removal efficiency, and energy consumption was considerably reduced with increasing conductivity. Hybrid processes were applied in this work to achieve higher COD removal efficiencies. In the case of aluminum electrode, polyaluminum chloride (PAC) was used as the coagulant aid for the aforesaid purpose. COD removal of 94.4% was obtained by adding 0.75 g L(-1) PAC. This removal efficiency corresponded to effluent COD concentration of 237 mg L(-1), which meets the legal requirement for discharge from slaughterhouses in Turkey. In the case of iron electrode, EC was conducted concurrent with the Fenton process. As a result, 81.1% COD removal was achieved by adding 9% H(2)O(2). Consequently, hybrid processes are inferred to be superior to EC alone for the removal of both COD and turbidity from cattle-slaughterhouse wastewater.     

Preparation and flocculation properties of cationic starch/chitosan crosslinking-copolymer

A novel flocculant (CATCS) based on corn starch and chitosan was prepared and its flocculation behaviors were studied. The synthesis conditions of CATCS were discussed and the production obtained was characterized using Fourier infrared spectra and scanning electron microscopy. Flocculation properties of the products were evaluated in terms of transmittance, removal of organic contaminant and solid suspending substances. Influences of temperature, pH and flocculant dosage on flocculation efficiency of CATCS were examined. CATCS had better flocculation performance at lower temperature for the wastewater investigated. CATCS showed better flocculation performance than cationic starch and chitosan in 5 g/L kaolin suspension trended to performance well in acidic and alkaline solution. The comparison of the flocculation performance between CATCS, Fe₂ (SO₄)₃ and polyacrylamide showed CATCS had much efficient flocculation performance. In addition, cationic starch was prepared from corn starch using microwave-assisted method.     

Coagulation/flocculation process and sludge conditioning in beverage industrial wastewater treatment

Attempts were made in this study to examine the effectiveness of coagulation and flocculation process using ferric chloride and polyelectrolyte (non-ionic polyacrylamide) for the treatment of beverage industrial wastewater. Removal of organic matter (expressed as chemical oxygen demand, COD), total phosphorus (TP) and total suspended solid (TSS) using ferric chloride and organic polyelectrolyte during coagulation/flocculation process were investigated. Also, the optimum conditions for coagulation/flocculation process, such as coagulant dosage, polyelectrolyte dosage, and pH of solution were investigated using jar-test experiment. The effect of different dosages of polyelectrolyte in combination with coagulant was also studied. The results revealed that in the range of pH tested, the optimal operating pH was 9. Percentage removals of 73, 95 and 97 for COD, TP and TSS, respectively, were achieved by the addition of 300mg/L FeCl(3).6H(2)O, whereas 91, 99 and 97% removal of COD, TP and TSS, respectively, were achieved with the addition of 25mg/L polyelectrolyte to 100mg/L ferric chloride. The volume of sludge produced, when ferric chloride was used solely, was higher compared to the use of combination of polyelectrolyte and FeCl(3).6H(2)0. The combined use of coagulant and polyelectrolyte resulted in the production of sludge volume with reduction of 60% of the amount produced, when coagulant was solely used for the treatment. It can be concluded from this study that coagulation/flocculation may be a useful pre-treatment process for beverage industrial wastewater prior to biological treatment.