混晶纳米二氧化钛光催化剂处理印染废水的研究

以混晶纳米二氧化钛为光催化剂,研究了pH值、光催化反应时间、纳米二氧化钛的用量及晶型、光源等因素对活性大红BES模拟印染废水和实际印染废水COD降解的处理效果.结果表明,对30 mL活性大红BES模拟印染废水,在溶液pH值为4、催化剂添加量为0.090 g时,紫外灯照射1 h,COD去除率可达到86%;对30 mL实际印染废水,在溶液pH值为9、催化剂添加量为0.150 g时,紫外灯照射1 h,COD去除率达到57%.     

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%.     

A comparative study of electrocoagulation and electro-Fenton for food industry wastewater treatment: Multiple response optimization and cost analysis

ABSTRACT

In this study, response surface methodology was applied for food wastewater by electrocoagulation (EC) and electro-Fenton (EF) processes. The optimum conditions for the chemical oxygen demand (COD) removal were found to be 21.36 min, pH 10 and 86 mA/cm² in EC, whereas 27.11 min, pH 2.38, 86 mA/cm² and H₂O₂/COD:2 in EF process. COD removal efficiencies were determined to be 29.4% for EC and 59.1% for EF processes and higher than 99% total suspended solids removal efficiencies were achieved. It can be concluded that high COD removal was obtained (4998 mg/L COD removal by EC and 10,047 mg/L COD removal by EF).     

Bilge Water Treatment in an Upflow Electrochemical Reactor using Pt Anode

Bilge water treatment was studied in an upflow electrochemical reactor (UECR) in order to design a compact onboard wastewater treatment system. The influence of retention time on the removal efficiencies of chemical oxygen demand (COD) and turbidity were analyzed, and optimized using response surface methodology (RSM) for maximizing the removal efficiencies. The best operating performance was obtained at 390 min retention time and 480 min reaction time for cost effective analysis with the composition of 100% bilge water (COD_o = 3080 mg/L) and 50/50% seawater/fresh water, 12.8 mA/cm² current density, and 32°C reaction temperature. Under response surface optimized conditions, the responses were estimated as; 90% COD removal, 97% turbidity removal, outlet pH value of 8.1, mass transfer coefficient of 0.494 × 10^?5 m/s, and mean energy consumption of 44.8 kWh/kg COD removed.     

固体废弃物预处理中药制药废水的实验研究

采用固体废弃物(铁屑和炉渣)预处理中药制药废水,并以COD去除率和脱色率为指标考察其处理效果。考察了废水pH值、试剂投加量、反应时间等对COD去除率及脱色率的影响,确定了最适工艺条件。结果表明,在弱酸性条件下内电解处理效果较好;加入适量的H2O2可明显提高对COD和色度的去除效果;内电解处理后投加适量的石灰乳对废水的COD去除和脱色均有利。废水预处理的最适工艺条件为:常温下,废水的pH为5.0~6.5,铁屑加入量为60 g/L,炉渣加入量为100 g/L,H2O2加入量为20 mL/L,反应30 min后,加入石灰乳(16 mL/L)调节pH至9。在此条件下,废水COD去除率及脱色率可分别达到73%和96%以上,而且处理成本较低。     

TiO_2光催化处理炼化污水回用反渗透浓水的研究

以悬浮态TiO2为催化剂,在紫外光下对炼化污水回用装置反渗透浓水进行光催化处理,采用单因素实验,考察了反应时间、pH值、光照强度、TiO2投加量、H2O2投加量、曝气量对处理效果的影响。结果表明:在反应时间为2 h,pH为4,500 W高压汞灯,TiO2投加量为0.6 g/L,H2O2投加量为0.8 ml/L,曝气量为0.75 L/min的条件下,反渗透浓水COD的去除率可达93.63%,脱色率可达98.15%。     

活性染料废水的混凝处理研究

采用化学混凝法,以MgSO4为混凝剂、阴离子聚丙烯酰胺为助凝剂,分别对棉布印染过程中排放的活性染料废水进行实验研究.结果表明,pH对脱色率有较大的影响,当pH＞12.0时,脱色率基本趋于稳定;脱色率及COD去除率均随MgSO4加量的增加而提高;加入阴离子聚丙烯酰胺可降低絮凝沉降时间.经混凝处理后废水的脱色率＞90%,COD去除率＞80%.该方法对处理棉布印染活性染料废水具有一定的适用性.     

杀螟硫磷生产废水的试验研究

研究了微波辐射条件下,以活性炭为催化剂,过氧化氢为氧化剂氧化处理杀螟硫磷生产废水。考察了微波功率、辐照时间、pH值、活性炭用量、过氧化氢用量对COD去除率的影响,在pH值为2.0、微波功率400W、微波辐照时间5 min、过氧化氢用量0.59 mol/L、活性炭用量120 g/L的条件下,废水COD去除率可达到65.9%,并对反应机理进行了初步探讨。     

Enhancing Biodegradability of Textile Wastewater by Ozonation Processes: Optimization with Response Surface Methodology

ABSTRACT

In this study, an ozonation process was used to increase biodegradability of textile wastewater by considering chemical oxygen demand (COD) and color removal. Response surface methodology was applied in order to determine the significance of independent variables which are initial pH, reaction time and ozone dose. While a biological oxygen demand (BOD)/COD rate of 0.315 was obtained at optimum conditions, which are pH 9, 75 min of reaction time and 26 mg/L ozone dose, color and COD removal was obtained at 74% and 39%, respectively. BOD/COD ratio value increased from 0.18 to 0.32 by ozonation process. In addition, k coefficient for BOD also increased from 0.21 to 0.30 d^?1.     

Application of Ni-doped ZnO nanorods for degradation of diazinon: Kinetics and by-products

The photocatalytic degradation of the organophosphorus insecticide diazinon in aqueous suspensions was studied by using Ni-doped ZnO nanorods as a photocatalyst. The effects of some operational parameters such as solution pH, nanocatalyst dosage, initial diazinon concentration, different purging gases, H₂O₂ concentration, and type of organic compounds on the removal efficiency were studied. Under optimal conditions: pH = 7, [Diazinon]₀ = 20 mg/L, nanocatalyst dosage = 0.2 g/L, H₂O₂ = 15 mM, 99.96% of the insecticide was removed after 120 min. Three kinetic models were developed for this process, and the findings showed that the diazinon removal rate obeyed the first-order kinetic.     

复合絮凝剂对染料废水的脱色作用

用羧甲基壳聚糖(CMCTS)复合聚合氯化铁(PFC)对相对分子质量较小的活性染料模拟废水进行脱色处理.结果表明,引入PFC作为助凝剂的脱色效果优于单纯使用CMCTS.采用此复合絮凝剂处理染料废水的最佳条件为pH=5,CMCTS和PFC的投加质量浓度分别为90 mg/L和2 mg/L.在此优化条件下,染料废水的脱色率可达93.8%,COD去除率达89.6%.     

改性焦渣复合吸附剂处理印染废水研究

实验研究了改性焦渣复合吸附剂热处理印染废水时各种因素的影响,结果表明：用十二烷基苯磺酸钠溶液改性焦渣并与活性炭质量比按10：1制成复合吸附剂,处理印染废水,在吸附剂用量为废水量0．4％,pH值控制在6,废水水温20℃,吸附时间20min的实验条件下,脱色率达90．8％,COD去除率达84．8％,SS去除率达到90．2％,处理效果良好。     

Application of TiO2/perlite photocatalysis for degradation of ammonia in wastewater

The purpose of this study was removal of ammonia by a new photocatalytic process from synthetic wastewater under UV irradiation. TiO₂ was used as the photocatalyst and immobilized on perlite granules as a supporter. The prepared catalysts were characterized by SEM and FTIR analysis showed that TiO₂/perlite catalyst has mesoporous structures and uniform coating of TiO₂ on support. Also, the optimum efficiency of photocatalytical degradation of ammonia was obtained at pH 11 for UV intensity irradiation with 125 W lamp. About 68% degradation of ammonia in wastewater was achieved after 180 min of irradiation by using the optimized reaction conditions.     

风化煤处理染料废水的实验研究

对风化煤吸附剂在常温下处理染料废水进行了实验研究,探讨了吸附时间、pH值和吸附剂用量对吸附效果的影响。结果表明,适量的吸附剂在OH值为11．5时吸附1d,对废水的脱色率可达99％左右,COD去除率在95％以上,BOD5可降低约80％。     

阳离子改性稻草处理印染废水研究

将稻草秸秆粉与2,3-环氧丙基三甲基氯化铵(EPTMAC)在NaOH催化下,于85℃反应6 h,合成季铵化度为97%的稻草季铵盐(QAS-RS),用于染料废液的处理,研究了QAS-RS用量、pH值和染液种类对脱色效果的影响。结果表明,0.13 g/L QAS-RS能使浓度为100 mg/L活性染料和酸性染料染液迅速脱色,COD去除率和脱色率最高达99.5%和98%,最低为86.3%和94%。     

Investigation of photocatalytic degradation of clindamycin antibiotic by using nano-ZnO catalysts

The photocatalytic degradation of clindamycin (CLM) was studied by a batch reactor using UV irradiation and ZnO catalyst. The effects of several parameters such as pH, catalyst loading, light intensity and irradiation time were evaluated in the removal process. The results showed that the degradation of CLM was effective in alkaline conditions. The optimum catalyst loading in an aqueous solution containing 25 mM of CLM and UV lamp of 50 W was observed at 3.0 g/L of catalyst loading. The process followed pseudo-first order kinetics, and the apparent rate constant (k) decreased with increasing the initial concentration of CLM. The photocatalytic process had higher removal efficiency in synthetic than actual wastewater in optimum conditions.     

用复相光催化剂WO3/CdS/W深度处理印染废水的研究

用复相光催化剂WO3/CdS/W对印染废水的深度处理进行了研究。探讨了光催化反应机理,讨论了复相光催化剂的组成、用量、试液、pH值、光照时间与COD、色度去除率的关系。实验结果表明：以WO3／CdS/W为复相光催化剂,其组成为m(WO3)/m(C dS)/m(W)=60:39:1(质量比）、用量为0.300g、试液pH为6.5、光照10h,印染废水的COD、色度去除率分别达到69.8%、71.0%.     

The combination of photocatalysis process (UV/TiO2(P25) and UV/ZnO) with activated sludge culture for the degradation of sulfamethazine

The major factors affecting the removal efficiency of sulfamethazine (SMT) by photocatalysis process in the presence of TiO₂ P25 or ZnO, namely the pH, the amount of catalyst and the initial SMT concentration were examined. The obtained results showed the absence of adsorption of SMT on the catalysts and the absence of degradation of SMT by direct photolysis under UV light in the absence of catalyst. The variation of the pH solution in the range 4–9 did not cause any significant degradation of SMT. The optimal amounts of each catalyst were, respectively, 0.5 and 0.25 g/L for TiO₂ P25 and ZnO. Increasing the initial SMT concentration impacted negatively the removal efficiency, which decreased from 31% to 13% and from 100% to 27% in the presence of TiO₂ P25 and ZnO in the presence of 10 mg/L and 50 of SMT after 30-min reaction time, respectively. The obtained results showed better efficiency of ZnO than TiO₂ P25 regarding both removal efficiency and chemical oxygen demand (COD) abatement. However, removal efficiency and COD abatement were not complete, even after 7 h of photocatalysis, about 92% and 41%, respectively. The biodegradability was examined after photocatalysis performed in the following conditions: [SMT]₀ = 50 mg/L, pH = 6, T = 25°C, ω = 360 rpm and 0.5 g/L of TiO₂ P25 or 0.25 g/L of ZnO. In these conditions, the removal efficiencies were, respectively, 26% and 41% in the presence of TiO₂ P25 and 55 and 92% in the presence of ZnO after 4 and 7 h of pretreatment times, respectively. The BOD₅/COD ratio increased substantially and, respectively, from 0 to 0.25 and from 0 to 0.16 in the presence of TiO₂ P25 and ZnO after 7 h of irradiation. Even if the limit of biodegradability (0.4) was not achieved, a subsequent biological treatment was considered in the presence of TiO₂ P25, leading to 58% COD abatement after a 28-day culture.     

Degradation of 1‐amino‐4‐bromoanthraquinone‐2‐sulfonic acid using combined airlift bioreactor and TiO2‐photocatalytic ozonation

BACKGROUND: Traditional treatment systems failed to achieve efficient degradation of anthraquinone dye intermediates at high loading. Thus, an airlift internal loop reactor (AILR) in combination with the TiO₂‐photocatalytic ozonation (TiO₂/UV/O₃) process was investigated for the degradaton of 1‐amino‐ 4‐bromoanthraquinone‐2‐ sulfonic acid (ABAS). RESULTS: The AILR using Sphingomonas xenophaga as inoculum and granular activated carbon (GAC) as biocarrier, could run steadily for 4 months at 1000 mg L^?1 of the influent ABAS. The efficiencies of ABAS decolorization and chemical oxygen demand (COD) removal in AILR reached about 90% and 50% in 12 h, respectively. However, when the influent ABAS concentration was further increased, a yellow intermediate with maximum absorbance at 447 nm appeared in AILR, resulting in the decrease of the decolorization and COD removal efficiencies. Advanced treatment of AILR effluent indicated that TiO₂/UV/O₃ process more significantly improved the mineralization rate of ABAS bio‐decolorization products with over 90% TOC removal efficiency, compared with O₃, TiO₂/UV and UV/O₃ processes. Furthermore, the release efficiencies of Br^? and SO₄^2? could reach 84.5% and 80.2% during TiO₂/UV/O₃ treatment, respectively, when 91.5% TOC removal was achieved in 2 h. CONCLUSION: The combination of AILR and TiO₂/UV/O₃ was an economic and efficient system for the treatment of ABAS wastewater. © 2012 Society of Chemical Industry     

酸改性粉煤灰对印染废水处理的实验研究

对原始粉煤灰进行了酸性改性,制备了酸改性粉煤灰,并用其对印染废水进行脱色处理。研究了粉煤灰及酸改性粉煤灰的投加量(质量浓度)、反应pH值、反应时间等因素对印染废水脱色效果的影响。实验结果表明:用原始粉煤灰对染料废水进行脱色处理,在粉煤灰投加量为50 g/L,反应时间为40 min,pH值为10的最佳反应条件下,脱色效率为63.45%。用盐酸改性粉煤灰对染料废水进行脱色处理,在酸改性粉煤灰投加量为25 g/L,反应时间为10 min,pH值为10时,最佳脱色效率达到88.73%。