Influence of Experimental Parameters in the Treatment of Distillery Effluent by Electrochemical Oxidation

The electrochemical oxidation of distillery effluent was studied in a batch reactor in the presence of supporting electrolyte NaCl using Mixed Metal Oxide (MMO) electrode. The effect of operating parameters such as current density, initial pH, and initial electrolyte concentration on the percentage of Chemical Oxygen Demand (COD) removal, power consumption, and current efficiency were studied. The maximum percentage removal of COD was observed to be 84% at a current density of 3 A/dm²at an electrolyte concentration of 10 g/l with an effluent COD concentration of 1000 ppm and at an initial pH of 6. The operating parameters for the treatment of distillery effluent by electrochemical process were optimized using response surface methodology by CCD. The quadratic regression models with estimated coefficients were developed for the percentage removal of COD and power consumption. It was observed that the model predictions matched with experimental values with an R² value of 0.9504 and 0.9083 for COD removal and power consumption respectively. The extent of color removal and oxidation of organic compounds were analyzed using UV spectrophotometer and HPLC.     

染料化工废水预处理实验研究

采用二级混凝沉淀工艺处理染料化工废水,探讨混凝剂种类、加入量和体系pH值对脱色效果的影响。实验结果表明,硫酸亚铁对染料废水脱色效果优于其他混凝剂。当进水色度为8000￣65000倍,COD浓度为2000￣10000mg/L,在pH为10.5条件下,硫酸亚铁投加量为500mg/L,活性凹凸棒投加量为80mg/L时,脱色率可高达97.69%,COD去除率最高可达76.86%,有利于后续生化处理。     

有机絮凝剂在染料中间体废水处理中的应用

采用新型絮凝剂处理染料中间体废水(色度2200：CODcr22800：pH13)色度去除率为93.2％，CODcr去除率为75．20％。废水的pH值、絮凝剂SD-1的用量、搅拌速度及时问、絮凝剂浓度对絮凝效果产生不同影响。其最佳工艺条件参数为pH=6；絮凝剂用量为0．8%;搅拌速度为100r／分；搅拌时间为4分钟；助凝剂5ppm：室温操作。     

SBR法处理皂素废水的驯化实验

以城市污水处理厂普通活性污泥为对象,按照浓度梯度法向其中通入皂素废水进行驯化实验。通过3个周期的运行,当皂素废水投加量从0.5%增加到5%时,COD去除率均保持在68.93%以上。结果表明,污泥已基本适应皂素废水特性,活性污泥驯化完成。     

仲丁灵生产废水混凝预处理研究

以仲丁灵生产废水为研究对象,COD(化学需氧量)与色度为指标,研究了几种混凝剂与新型混凝脱色剂DH复合使用的混凝处理特性。通过不同的投配选择,得出了最佳的复合投加方式以及最佳药剂投加量。结果表明,采用硫酸亚铁与混凝脱色剂这种投加方式对该生产废水的预处理效果最佳,其色度去除率为70%,COD去除率为58%,有利于后续的生化处理;确定了最佳的药剂投加量为硫酸亚铁200mg/L,混凝脱色剂DH为250mg/L。     

臭氧氧化法处理煤化工难降解废水实验研究

某煤化工废水经生物处理后COD仍然在500mg／L以上,色度较大,为保证后处理排水达标,对该废水进行臭氧氧化处理。经实验,处理1L废水时的最佳反应条件为进气流量0．6m3／h,产臭氧量7．73mg／min,气循环1．0m3/h,反应时间30min。处理后COD去除率为30％,废水B／C达到0．3,色度达80％。     

卤水对碱性印染废水脱色处理的初步研究

采用含镁量高的废弃卤水处理碱性印染废水。考察了pH值、卤水投加量、温度、沉降时间对脱色率的影响。实验表明:废水的脱色率主要受pH值、卤水投加量的影响,温度也有一定的影响。pH11时脱色率可达98%以上。利用废弃的卤水对印染废水进行脱色处理具有实际应用前景。     

几种混凝剂应用于活性染料印染废水的脱色研究

应用PAC、BT-03、BT-04三种混凝剂处理了活性染料模拟废水和实际印染废水,研究了它们对以活性染料为主的印染废水脱色效果。结果表明,BT-03脱色效果较好。     

臭氧预氧化/混凝处理活性藏青废水的试验研究

文章采用臭氧预氧化与三氯化铁混凝联用工艺处理活性藏青印染废水,考察了臭氧流量、三氯化铁投加量、pH、废水温度等参数对活性藏青废水色度去除率和CODCr去除率的影响。结果表明在臭氧流量为40 L/h,通气时间为3 min,三氯化铁投加量为200 mg/L,pH为7,混凝温度为30℃的条件下,臭氧预氧化与三氯化铁混凝联用工艺对活性藏青废水有比较理想的降解效果,印染废水的色度去除率达到95.3%,CODCr去除率达到71.5%。     

UASB反应器处理制膜废水的试验研究

利用升流式厌氧污泥床(UASB)反应器在中温条件下处理高浓度难降解的制膜废水。当UASB反应器稳定运行时,进水CODCr=10000mg·L-1时,COD容积负荷可达到9~11kg·m-3.d-1,水力停留时间24h,COD去除率可以达到85%以上,出水COD小于1500mg·L-1。通过本试验取得的良好试验效果,为利用厌氧技术处理制膜废水提供了设计依据。     

重金属在城市污水处理中的去除机理

由于重金属的毒性及致癌性,受重金属污染水体备受关注,去除水体中的重金属势在必行。活性污泥作为一种生物吸附剂,在处理低浓度重金属废水应用中前景广泛。以活性污泥为核心的城市污水处理厂在有效去除有机物的同时,对重金属也有一定的去除能力。通过综述城市污水系统中重金属迁变特性的最新研究,分析了活性污泥处理重金属废水的优越性、国内外污水处理厂对重金属的去除效果,推导出活性污泥去除重金属的可能机理,最后展望了城市污水处理厂去除重金属的前景和发展方向。     

UV-Fenton体系处理活性黑KNB染料废水的实验研究

采用UV-Fcnton体系处理活性黑KNB染料废水．研究了pH值、H2O2和FeSO4用量、反应温度和反应时间等对染料废水脱色率的影响。实验结果表明,当KNB的初始浓度为50mg／L时,在t=25℃、pHi5．4、[H2O2]=0．2ml/L,[FeSO4]=0．7mmol/L。使用30W的紫外灯光照射条件．反应1小时后,KNB染料废水脱色率几乎可达100%。通过比较反应前后染料废水的UV-Vis吸收光谱,初步探讨了KNB的降解机理。研究表明,UV-Fenton体系可以有效地处理活性黑KNB染料废水,为该工艺处理实际染料废水提供基础数据。     

上流式厌氧污泥床反应器处理凉果废水性能研究

采用上流式厌氧污泥床反应器(UASB)法处理凉果废水,考察废水厌氧处理过程中COD、浊度、脱色率、pH、电导率、悬浮物去除率的变化规律。结果表明:随着厌氧时间的增加,UASB反应器对废水的处理效果不断提高。在最适宜的厌氧时间条件下,废水的COD去除率达62.0%、浊度去除率达41.1%、吸光度及脱色率分别为0.498及48.4%、pH为5.4、悬浮物去除率达30.3%。故,UASB法可作为凉果废水的预处理方式,以降低后续废水的好氧处理难度。     

Improving Dewaterability and Other Properties of Citric Acid Wastewater Treatment Sludge by Ozone and Peroxone

ABSTRACT

The efficacies of ozonation and peroxone (O₃/H₂O₂) pretreatments were compared for citric acid wastewater sludge conditioning with the objective of improving dewatering characteristics of the sludge. Treatment with 84 mg O₃/g dry solid (DS) and 12.5 mg/g DS H₂O₂ greatly enhanced the effectiveness of ozonation, providing sludge dewaterability similar to that obtained by ozonation at 250 mg O₃/g DS. Most importantly, treatment of citric acid wastewater sludge with 84 mg O₃/g DS and 12.5 mg/g DS H₂O₂ led to the preservation of the nutrient elements nitrogen, phosphorus, and potassium in the sludge with a minimal volatile suspended solids/total suspended solids reduction of 5.5%, which is much lower than that with ozonation at 250 mg O₃/g DS.     

Evaluation of the Efficiency of a Combined Adsorption–Ultrafiltration System for the Removal of Heavy Metals,Color, and Organic Matter from Textile Wastewater

In this work an ultrafiltration (UF) membrane system was investigated for the treatment of textile wastewater. UF membranes were assisted by activated sludge and minerals, which were employed as sorbents, to remove Cu(II), Pb(II), Zn(II), Ni(II), color, and organics. Significant variations were observed in metal removal efficiencies among the textile wastewater samples of different origin, even at the same pH (= 6) due to the presence of different compounds in wastewater. At the examined pH range (5.63–9.21), the dominant mechanism for copper and lead removal was the formation of insoluble metals due to precipitation and complexation of metal ions with wastewater compounds, including adsorption of metals on suspended solids and colloidal matter. The adsorption process of metals on minerals and activated sludge was the dominant process for nickel and zinc removal at low pH, while precipitation/complexation prevailed at higher pH. The examined adsorption-UF system could produce a treated effluent having low metal concentrations that could be safely discharged into municipal sewers. COD removal ranged from 76%–92% for the five textile wastewater samples. The color removal accomplished was significant (45%–70%), and depended on the type of dye.     

经表面修饰的FeO(OH)胶粒制备动态膜及其脱色性能

研究了FeO（OH）动态膜的膜通量衰减与FeO（OH）胶粒的凝并关系。以阴离子表面活性剂对FeO（OH）胶粒表面修饰并将其形成的动态膜与未修饰时比较,结果显示：成膜时间从6～8h减少至1～2h;在同样成膜压力（0.11MPa）下,膜通量增大13．2％,在最大值条件（0．24MPa和0．11MPa）下,膜通量增大24．1％;用该膜处理印染厂二沉池排水,脱色率高达98．5%,膜通量增加40％-150％,运行周期提高2～3倍。     

Purification of Phenolic Wastewater Using Aerobic Bio-oxidation Combined with Activated Carbon Treatment and Ozonation

The combined process – aerobic bio-oxidation with activated carbon addition and ozonation was studied (ABO/AC/O3). The performance of the process was compared with conventional aerobic bio-oxidation (ABO). The studies were carried out in two continuous and periodic reactors to evaluate the purification efficiencies (in terms of COD, BOD and resorcinols removal), excess sludge generation and stability of the bioreactors against shock loadings. The parameters in continuous combined process were as follows: organics loading was 620 mgCOD/(day·L), activated carbon concentration 1g/L and ozone dose 2.45 mgO₃/L (mg ozone per liter of treated water). In periodic reactors the combined process was studied at lower activated carbon concentration and ozone dose (0.3 g/L and 0.57 mg/L respectively).

The results indicated that compared with conventional ABO, the co-effect of AC addition and short-termed (less than 1 week) or intermittent ozonation improved the removal of COD and BOD, while the longer period of ozonation resulted in reduction of excess sludge concentration in the bioreactor. The impact of AC and ozone on the ABO in the combined process did not concern only increased biomass activity, but AC and ozone improved also settleability of activated sludge and enhanced stability of the bioreactor to shock loadings.     

Cu~(2+)/H_2O_2法降解高浓度偏二甲肼废水

采用Cu~(2+)/H_2O_2法降解高浓度偏二甲肼(UDMH)废水,以废水中UDMH的去除率作为检测指标,通过正交实验确定了该反应的主要影响因素及最佳工艺条件,考察了最佳工艺条件下的降解效果;针对化学需氧量(COD)去除率低的问题,探讨了降解中间产物甲醛和亚硝基二甲胺的变化规律。结果表明,H_2O_2摩尔投加量为UDMH完全矿化理论摩尔投加量的1.5倍(1.5Qth)、初始pH值为9、Cu~(2+)与H_2O_2摩尔比1∶10、反应温度为20℃、反应进行120min后,废水中UDMH的降解率达98.88%,COD去除率达92.59%。但Cu~(2+)/H_2O_2法处理时产生有毒中间产物亚硝基二甲胺和甲醛,反应后期甲醛迅速降解,而亚硝基二甲胺则难以去除。