Integrated ozone–photo–Fenton process for the removal of pollutant from industrial wastewater

The use of hybrid advanced oxidation processes(AOPs) for the removal of pollutants from industrial effluents has been extensively studied in recent literature. The aim of this study is to compare the performance of the photo,Fenton, photo-Fenton and ozone–photo–Fenton processes in terms of color removal and chemical oxygen demand(COD) removal of distillery industrial effluent together with the associated electrical energy per order. It was observed from the experimental results that the O_3/UV/Fe~(2 +)/H_2O_2 process yielded a 100% color and95.50% COD removals with electrical energy per order of 0.015 k W·h·m~(-3) compared to all other combinations of the AOPs. The effects of various operating parameters such as H_2O_2 and Fe~(2+) concentration, effluent pH, COD concentration and UV power on the removal of color, COD and electrical energy per order for the ozone–photo–Fenton process was critically studied and reported. The color and COD removals were analyzed using a UV/Vis spectrometer and closed reflux method.     

N, O-羧甲基壳聚糖复合纳滤膜的制备及其对酒厂发酵废水的截留效果

N, O-carboxymethyl chitosan （NOCC） composite nanofiltration （NF） membranes were prepared by coating and cross-linking. The fermentation effluent from a wine factory was treated with the resulting NOCC/polysulfone （PSF） composite NF membranes. The permeate flux and the removal efficiencies of the resulting NF membranes for the color, chemical oxygen demand （CODcr）, total organic carbon （TOC）, and conductivity of the fermentation effluent were investigated in relation to the driving pressure, the feed flow, and the operation time. The permeate flux and the removal efficiencies were found to increase with the increase of the driving pressure or the feed flow. At 0.40 MPa and ambient temperature the removal efficiencies were 95.5%, 70.7%, 72.6%, and 31.6% for color, CODcr, TOC, and conductivity, respectively. The membrane was found to be stable over a 10-h ooeration for the fermentation effluent treatment.     

Treatment of compost leachate by the combination of coagulation and membrane process☆

This study describes the treatment of composting leachate by the combination of coagulation and nanofiltration process.Poly ferric sulfate(PSF) was used as coagulant,and the effect of p H value and PSF dosage on the coagulation performance was investigated.The results indicated that the chemical oxidation demand(COD)and turbidity removal efficiency could reach to 62.8% and 75.3%,respectively at an optimum dosage of1200 mg·L~(-1)at p H 6.0.During the nanofiltration process,the operation conditions such as temperature and pressure were optimized,89.7% of COD,78.2% of TOC,72.5% of TN,83.2% of TP,and 78.6% of NH3-N were retained when tested at 0.6 MPa at 25 °C.The final leachate effluent concentration of COD,BOD5,NH3-N,TOC,SS was92 mg·L~(-1),31 mg·L~(-1),21 mg·L~(-1),73 mg·L~(-1)and 23 mg·L~(-1),respectively,which reached the local discharge standard.The combination of coagulation-filtration is useful for composting leachate treatment.     

Wet oxidation of PVA-containingdesizing wastewater

Polyvinyl alcohol (PVA)-containing desizing wastewater was treated by various wet oxidation methods.Parameters such as reaction temperature, initial solution pH, and the dosage of H2O2 were investigated in terms of chemical oxygen demand (CODcr) and total organic carbon (TOC) removal rate. Up to 90% of the initial CODcr was removed by wet air oxidation(WAO) at 270℃ with stoichiometric oxygen supply, while at temperature of 200℃, the CODcr removal rate was found to be 80%. Similar results were obtained by Promoted WAO (PWAO) and wet peroxide oxidation(WPO) at a lower temperature of 150℃. Reaction temperature was found to have a significant effect on the oxidation performance for all the methods. Initial solution pH was observed to play a significant role in PWAO and WPO where H2O2 was employed. Comparison of WAO, CWAO(catalytic wet air oxidation), PWAO and WPO shows that the rate of CODcr removal increases in the order: WAO, CWAO, PWAO and WPO.     

Biological Nutrient Removal in a Full Scale Anoxic/Anaerobic/Aerobic/ Pre-anoxic-MBR Plant for Low C/N Ratio Municipal Wastewater Treatment

A novel full scale modified A2O （anoxic/anaerobic/aerobic/pre-anoxic）-membrane bioreactor （MBR） plant combined with the step feed strategy was operated to improve the biological nutrient removal （BNR） from low C/N ratio municipal wastewater in Southern China. Transformation of organic carbon, nitrogen and phosphorus, and membrane fouling were investigated. Experimental results for over four months demonstrated good efficiencies for chemical oxygen demand （COD） and NH4^＋-N removal, with average values higher than 84.5%and 98.1%, re-spectively. A relatively higher total nitrogen （TN） removal efficiency （52.1%） was also obtained at low C/N ratio of 3.82, contributed by the configuration modification （anoxic zone before anaerobic zone） and the step feed with a distribution ratio of 1：1. Addition of sodium acetate into the anoxic zone as the external carbon source, with a theoretical amount of 31.3 mg COD per liter in influent, enhanced denitrification and the TN removal efficiency in-creased to 74.9%. Moreover, the total phosphate （TP） removal efficiency increased by 18.0%. It is suggested that the external carbon source is needed to improve the BNR performance in treating low C/N ratio municipal waste-water in the modified A^2O-MBR process.     

UV/O3/H2O2化学氧化活性艳蓝KN-R

以商品染料活性艳蓝KN-R为研究对象，利用VC／O3/H2O2技术进行氧化处理。考察了染料溶液在此过程中的pH、电导率、COD、TOC和吸光度的变化。经过70min的氧化过程，结果表明，溶液的pH降低、电导率不断升高、色度去除率达98．9％，溶液的COD和TOC去除率分别为47％和5％。VC／O3/H2O2技术与UV/H2O2氧化法相比，UV／O3/H2O2能显著去除染料溶液的色度。     

改进型分段进水厌氧/缺氧/好氧工艺强化营养物去除

In order to enhance phosphorus removal in traditional step-feed anoxic/oxic nitrogen removal process,a modified pilot-scale step-feed anaerobic/anoxic/oxic (SFA²/O) system was developed,which combined a reactor similar to UCT-type configuration and two-stage anoxic/oxic process.The simultaneous nitrogen and phosphorus removal capacities and the potential of denitrifying phosphorus removal,in particular,were investigated with four different feeding patterns using real municipal wastewater.The results showed that the feeding ratios(Q₁)in the first stage determined the nutrient removal performance in the SFA²/O system.The average phosphorus removal efficiency increased from 19.17% to 96.25% as Q₁ was gradually increased from run 1 to run 4,but the nitrogen removal efficiency exhibited a different tendency,which attained a maximum 73.61% in run 3 and then decreased to 59.62% in run 4.As a compromise between nitrogen and phosphorus removal,run 3 (Q₁=0.45Q_total) was identified as the optimal and stable case with the maximum anoxic phosphorus uptake rate of 1.58mg·(g MLSS)^-1·h^-1.The results of batch tests showed that ratio of the anoxic phosphate uptake capacity to the aerobic phosphate uptake capacity increased from 11.96% to 36.85% with the optimal influent feeding ratio to the system in run 3,which demonstrated that the denitrifying polyP accumulating organisms could be accumulated and contributed more to the total phosphorus removal by optimizing the inflow ratio distribution.However,the nitrate recirculation to anoxic zone and influent feeding ratios should be carefully controlled for carbon source saving.     

Enhanced biological nutrient removal in modified carbon source division anaerobic anoxic oxic process with return activated sludge pre-concentration☆

A pilot-scale modified carbon source division anaerobic anoxic oxic (AAO) process with pre-concentration of returned activated sludge (RAS) was proposed in this study for the enhanced biological nutrient removal (BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratio were investigated. The results show that the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60%and 50%, respectively, with an inner recycling ratio of 100%under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L?1 with a removal efficiency of 63%and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test.     

空化水射流结合双氧水降解苯酚(英文)

The paper presents results of phenol oxidized under the conditions of high temperature created during collapse of cavitation bubbles.The degradation efficiency has been greatly improved by using cavitation water jets combined with H2O2 as demonstrated in laboratory tests.Various factors affecting phenol removal ratio were ex-amined and the degradation mechanism was revealed by high performance liquid chromatography(HPLC).The re-sults showed that 99.85% of phenol was mineralized when phenol concentration was 100 mg·L-1 with pH value of 3.0,H2O2 concentration of 300 mg·L-1,confining pressure of 0.5 MPa,and pumping pressure of 20 MPa.The in-termediate products after phenol oxidation were composed of catechol,hydroquinone and p-benzoquinone.Finally,phenol was degraded into maleic acid and acetic acid.Furthermore,a dynamic model of phenol oxidation via cavi-tation water jets combined with H2O2 has been developed.     

CaCl2-LiBr-LiNO3-KNO3/H2O工质对的热物性和腐蚀性

The new working pair of CaCl2?LiBr?LiNO3?KNO3 (mass ratio 16.2:2:2:1)/H2O was systematically evaluated in terms of the crystallization temperature and the saturated vapor pressure. The corrosion rates of the carbon steel, 316L stainless steel and copper in CaCl2?LiBr?LiNO3?KNO3/H2O were measured with a weight loss method. The results showed that under the same refrigeration conditions, the temperature required for collecting solar energy or the generation temperature of CaCl2?LiBr?LiNO3? KNO3/H2O for a single-stage absorption refrigeration cycle decreases by 6.2℃ comparing with LiBr/H2O. The corrosion rates of 316L and copper are low enough for practical applications.     

湿式空气催化氧化预处理阿普拉霉素废水

研究了阿布拉霉素废水的湿式空气氧化和混凝-酸解预处理技术。分析了COD、阿布拉霉素、NH4＋浓度、BOD5/COD。监测了废水的色度和味。在1L反应器中,于200℃和4 MPa条件下,对阿布拉霉素废水进行了无催化剂、RuO2/Al2O3和RuO2/CeO2/Al2O3的湿式空气氧化。结果表明在湿式空气氧化法中,使用催化剂RuO2/Al2O3和RuO2/CeO2/Al2O3反应150 min后,阿布拉霉素的去除率分别达到50.2%和55.0%,COD去除率达到40.0%和46.0%,BOD5/COD增加到0.49和0.54。使用混凝-酸解法预处理,COD和阿布拉霉素去除率轻微下降,BOD5/COD增加到0.45,污水不适合生物处理。在WAO中,废水的色度和味被有效控制,反应时间明显缩短。在阿布拉霉素废水的湿式空气氧化中,HO2.可以促进有机化合物氧化。CeO2的加入能够促进阿布拉霉素废水的湿式空气氧化中催化剂RuO2/Al2O3的活性和稳定性。     

阿奇霉素废水的预处理

针对阿奇霉素废水高COD、高氨氮浓度、高色度以及高含盐量的特点,采用吹脱-铁炭微电解-Fenton氧化预处理阿奇霉素废水,效果良好。试验结果表明：吹脱pH值为11～12、吹脱时间20 h时,氨氮去除率达到80%;铁炭微电解pH值为3～4、铁炭比为1.5、反应时间为80 min时,COD去除率达到45%;向微电解出水投加30 mL/L的H₂O₂（质量分数为30%）进行Fenton氧化处理,COD去除率提高到89.6%。预处理后,废水的BOD₅/COD从0.18提高到0.3,提高了废水的可生化性。     

吸附-混凝-高级化学氧化法处理庆大霉素废水的研究

采用吸附－混凝－高级化学氧化法,对庆大霉素废水进行处理,筛选出最佳的混凝条件及氧化条件。实验发现,采用聚合氯化铝（PAC）和阳离子聚丙烯酰胺（CPAM）复合混凝该废水,在pH为8,PAC与CPAM的用量分别为400mg/L和10mg/L时混凝效果较好。混凝后的废水再用H2O＋Fe^2 UV氧化,当pH为3时,采取三次投加方式加入2．4g/LH2O2,紫外灯照射6h,取得了满意的结果,实验结果表明：采用吸附－混凝－高级化学氧化处理庆大霉素废水是一种行之有效的途径。经该方法处理后的庆大霉素废水,其CODCR去除率为99．1％,脱色率达100％,达到了医药行业废水排放标准。且该方法设备简单,易于下一步实现工业放大,是一种有较好开发前景的处理庆大霉素废水工艺。     

H_2O_2/O_3体系处理反渗透浓缩垃圾渗滤液

采用H2O2/O3体系处理经反渗透膜处理后的浓缩垃圾渗滤液,比较了H2O2/O3体系和单独H2O2和单独O3处理浓缩液;并考察了体系初始pH值、O3投量、H2O2投量对H2O2/O3体系降解浓缩液的色度、腐殖酸以及COD的去除的影响;以及考察了H2O2/O3体系对浓缩液中大分子的胡敏酸（HA）以及中等分子量的富里酸（FA）的去除,并通过E250/E365（E2/E3）和E240/E420（E2/E4）的变化表征腐殖酸的腐殖度的变化。结果表明：H2O2/O3体系的处理效果远好于单独H2O2和单独O3处理;在pH值为8.0、O3投量为5.02 g/h、H2O2投量为90 mmol/L、反应时间为30 min时,H2O2/O3体系处理浓缩液的色度、腐殖酸和COD的去除率分别达到97.72%、88.85%和74.54%;O3/H2O2氧化体系对HA的去除率高于FA,且经过O3/H2O2氧化体系处理后浓缩液中腐殖酸分子量降低,腐殖化程度降低。     

Fenton试剂预处理丁硫克百威废水的实验研究

通过单因素实验考察Fenton试剂预处理丁硫克百威生产废水,研究了反应初始pH值、七水合硫酸亚铁投加量、双氧水投加量和反应时间等因素对废水COD去除率和呋喃酚去除率的影响。结果表明:Fenton法预处理丁硫克百威废水的优化条件是pH=3.0、七水合硫酸亚铁投加量为5.6 g/L、双氧水投加量为25.0 mL/L、反应时间为120 min,在此条件下废水的COD去除率为60.6%,呋喃酚去除率为74.3%,BOD5/COD从0.07上升至0.36,改善了废水水质,保障了后续生化处理条件,为企业废水处理提供了切实可行的理论依据。     

混凝-Fenton-SBR联用工艺处理印刷线路板乳化废液

采用混凝-Fenton-SBR法处理印刷线路板乳化废液,实验结果表明,采用聚合氯化铁(PFC),在pH值为6.3,投加量为2800mg/L的条件下,COD去除率约为80.9%。混凝后废水利用Fenton处理,在pH=3时,H2O2用量为50g/L,FeSO4·7H2O的用量为5g/L时,废水COD降为1342mg/L,BOD降为657mg/L,废水的可生化性指数为0.49,可利用SBR处理,生化出水COD浓度低于485mg/L,可达到《广东省水污染物排放限值》(DB44/26-2001)中COD的三级排放标准。     

超声波-Fenton法协同降解含表面活性剂SDS弱酸艳红染料废水的研究

采用Fenton氧化、超声辐射和超声-Fenton氧化三种方法处理含阴离子表面活性剂SDS的弱酸艳红B染料废水,考察溶液初始pH、H2O2投加量、FeSO4投加量、反应时间和超声功率对废水色度和COD的影响。结果表明:单独超声对废水色度和COD的去除没有效果,超声-Fenton氧化法对废水COD的去除效果明显优于Fenton氧化法。在pH 2.5,温度50℃,H2O2投加量4 mL/L,FeSO4投加量300 mg/L,反应时间90 min及超声功率400 W的条件下,废水色度去除率为98%,COD去除率为72%,比单独Fenton氧化法COD去除率提高25%。     

O3/UV高级氧化法去除腈纶废水生化出水中COD的研究

运用0/3UV协同高级氧化法处理睛纶废水生化出水,调整污水中污染物的浓度和反应初始PH值,考察处理后COD去除率的变化情况,并观察反应进行时间对COD去除率的影响;尝试向反应用水中添加适量的NaHC03,与不添加的情况比较,观察COD去除率的变化.实验结果表明,原污水稀释2倍后再进行高级氧化处理更为合理;当反应进行时间...