高级氧化+SBR工艺处理聚乙二醇废水试验研究

研究了高级氧化+SBR组合工艺处理高浓度聚乙二醇(PEG)废水的效果及其影响因素。结果表明,采用芬顿试剂作为高级氧化剂,当FeSO4.7H2O投加量为800 mg/L,H2O2投加量为30 mL/L,反应时间为3.5 h时,CODCr去除率可达到50.5%;生化处理阶段所需采用两级SBR工艺,污泥浓度均为4 000 mg/L,一、二级厌氧及好氧反应时间分别为12和10 h;芬顿试剂氧化和厌氧处理对提高PEG废水的可生化性有明显效果;该组合工艺的出水水质可以达到《污水综合排放标准》(GB 8978—1996)中的二级排放标准。     

甲苯二异氰酸酯(TDI)生产废水处理工程实例

针对某集团公司排放的甲苯二异氰酸酯(TDI)生产废水,采用自然冷却/一体化全混微电解/芬顿氧化/中和絮凝沉淀工艺进行物化预处理后,再与聚氯乙烯(PVC)生产废水以及其他杂排水形成综合废水。采用水解酸化/好氧活性污泥/生物接触氧化处理和末端混凝沉淀/末端氧化深度处理的组合工艺处理综合废水。工程实践表明,物化预处理可大幅降低TDI生产废水中有机污染物浓度和生物毒性,生化和深度处理能够稳定有效处理综合废水,出水水质达到《污水综合排放标准》(GB 8978—1996)的一级标准。     

催化氧化/组合生化工艺处理丁苯橡胶废水的中试

针对丁苯橡胶生产废水组分复杂,常规工艺难以有效处理的特点,采用催化氧化/组合生化工艺进行现场中试,考察了整个系统的处理效果。结果表明:臭氧催化氧化可显著提高丁苯橡胶废水的处理效果,水解酸化/臭氧催化氧化/膜生物反应器(MBR)组合工艺运行稳定、可靠,对COD、NH3-N的平均去除率分别为91.8%和88.3%,出水水质可稳定达到天津市《污水综合排放标准》(DB 12/356—2008)的二级标准。     

高浓度石化废水综合处理工程

采用气浮/铁炭曝气/芬顿氧化/UASB/生物接触氧化工艺处理高浓度石化废水,介绍了系统的启动与运行情况.工程实践表明,该组合工艺对COD、色度等均有较好的去除效果,处理后出水水质达到<污水综合排放标准>(GB 8978-1996)的一级标准.     

某制剂类制药废水处理工程实例

制剂类制药废水生物毒性较大、可生化性较差,属较难降解有机废水。采用混凝沉淀+上升式厌氧污泥床+生物接触氧化工艺进行处理。运行结果表明,该工艺处理效果稳定,抗冲击负荷能力强,出水COD300 mg/L,出水水质达到《污水综合排放标准》(GB 8978—1996)表4中的二级排放标准。     

港口液体化学品废水处理工程实例

液体化学品废水有毒有害物质多,水质波动大.采用隔油气浮/曝气生物滤池蠕动床/臭氧氧化/曝气生物滤池固定床组合工艺进行处理,COD由进水的1 200 mg/L左右降到100 mg/L以下,SS由进水的600 mg/L左右降到30 mg/L以下,出水水质达到<污水综合排放标准>(GB 8978-1996)的一级标准,可回用作生活杂用水.实际运行结果表明,该组合工艺有效、稳定,污泥产量少,可操作性强,有很好的环境效益和经济效益.     

高浓度中药制剂废水处理工程设计

针对中药制剂生产废水有机物浓度高、成分复杂、水量变化大的特点,某药业公司废水处理采用了高、低浓度废水分质处理的方法。为满足《黄河流域(陕西段)污水综合排放标准》(DB 61/224—2011)的一级标准,对高浓度废水采用了稀释、UASB、Fenton试剂氧化的组合处理工艺,其出水再与低浓度废水混合为综合废水,经生物接触氧化、曝气生物滤池组合工艺处理后,出水水质达到了排放标准。     

Fenton-混凝沉淀-水解酸化-A/O工艺处理医药废水

针对浙江某医药厂高浓度难降解医药废水的特点,设计将高浓度废水先经芬顿(Fenton)氧化处理后与低浓度废水混合,再采用混凝沉淀、水解酸化、缺氧/好氧(A/O)工艺进行后续处理,处理水量为120 m~3/d。工程实践结果表明,Fenton氧化处理有效提高了废水的可生化性,该组合工艺能够稳定高效地处理医药废水,实现了良好的脱氮除磷效果,出水水质达到《污水综合排放标准》(GB 8978—1996)的三级排放标准,且其中氨氮、总磷达到《污水排入城镇下水道水质标准》(GB/T 31962—2015)的B级标准。     

声电与生物氧化联合处理医药化工废水

采用声电协同法作为预处理工艺,联合生物法处理医药化工废水,处理规模为1 000m3/d.运行实践表明,声电工艺与生物法联用,可提高废水的生物降解性.整个系统对COD的去除率达到99.26％,出水pH值为8.2、COD为233 mg/L,达到《污水综合排放标准》(GB 8978-1996)的三级标准.     

水解酸化/两段生物接触氧化去处理锦纶6生产废水

锦纶6生产废水为可生化性良好的含氮有机废水,采用水解酸化-两段生物接触氧化工艺处理该废水,考察了硝化液回流比、水力停留时间及溶解氧浓度对处理效果的影响.结果表明,在硝化液回流比为3、水力停留时间为12.1 h以及水解酸化池和1#、2#接触氧化池的溶解氧浓度分别为(0.5～1.0)、(3.0～3.5)和(1.8～2.3)mg/L的条件下,系统的处理效果最好,对COD和TN的去除率分别为95.85%和61.04%,出水水质达到了《污水综合排放标准》的一级标准.     

Enhanced biodegradation of petrochemical wastewater using ozonation and BAC advanced treatment system

The characteristics of degradation/conversion of bio-refractory and the growth of a biofilm are investigated in laboratory-scale pre-ozonation and lifted moving-bed biological activated carbon (BAC) advanced treatment processes treating phenol, benzoic acid, aminobenzoic acid and petrochemical industry wastewater which contains acrylonitrile butadiene styrene (ABS). The optimal reaction time and ozone dosage of pre-ozonation for bio-refractory conversion were determined to be 30 min and 100-200 mg O3/hr, respectively. After pre-ozonation of 30 min treatment, BOD5/COD ratio of influent and effluent increased apparently from 20 to 35%, approximately. However, the change of pH in pre-ozonation was inconspicuous. The optimal flow rate of influent and air were controlled at 1.6 l/h and 120-150 nl/min in lifted moving-bed BAC advanced treatment reactor. A COD removal efficiency of 85-95% and 70-90% may be maintained by using an organic loading of 3.2-6.3 kg COD/m3 day and 0.6-1.6 kg-COD/m3 day with an HRT of 6.0 h as secondary and advanced treatment system, respectively. The time required for the BAC bed is be regenerated by a thermal regeneration is prolonged 4-5 times more than that of GAC system. It can be estimated that the enhanced COD removal capability of the biofilm was not only due to the increase in the COD removal capability of acclimated bacteria, but also due to species succession of bacteria in bio-film ecosystem.     

Chemical treatment of an anionic surfactant wastewater: Electrospray-MS studies of intermediates and effect on aerobic biodegradability

The effect of wet air oxidation on the aerobic biodegradability of a model wastewater containing 1000 mg L(-1) of linear alkylbenzene sulfonate (LAS) has been investigated. Semibatch oxidation experiments were performed temperature of 473 K, oxygen partial pressure of 1.3 MPa and residence times varying from 40 to 390 min, while continuous oxidation experiments were performed at a residence time of 120 min. Oxygen uptake tests were performed to assess the aerobic biodegradability of both the oxidised and the original LAS solutions using cultures that had been adapted to both LAS and oxidation intermediates. The concentration of total organic carbon, chemical oxygen demand and active detergent were followed throughout the wet oxidation and biodegradation experiments, while the main intermediates formed during wet oxidation were identified by means of Electrospray-MS and high performance liquid chromatography. It was found that LAS could be easily oxidised at 473 K to yield a group of molecules with short alkyl chains which do not behave as active detergents. Sulfonated aromatics are produced as intermediates which have had the alkyl chains shortened. The segments of alkyl chains broken off the intermediate compounds appear primarily as short chain organic acids. The original unoxidised 1000 mg L(-1) LAS solution was found to be readily biodegradable in the laboratory aerobic reactors operating at low organic loadings and substrate to microorganism concentration ratios. However, wet oxidation resulted in effluents that were less readily biodegradable than the original LAS with biodegradability decreasing with increasing degree of oxidation. These results suggest that, at the conditions under consideration, a combined chemical pre-oxidations and biological post-treatment process may be less effective in removing LAS than a single-stage biological or chemical process.     

Advanced treatment of the reverse osmosis concentrate produced during reclamation of municipal wastewater

The work investigated the treatment of the concentrate produced from the reverse osmosis treatment of an MBR effluent. Two conventional chemical processes, coagulation and activated carbon adsorption, and three advanced oxidation processes (electrochemical treatment, photocatalysis and sonolysis) were applied. Coagulation with alum gave dissolved organic carbon (DOC) removals up to 42%, while FeCl(3) achieved higher removals (52%) at lower molar doses. Adsorption with granular activated carbon showed the highest DOC removals up to 91.3% for 5 g/L. The adsorption isotherm was linear with a non-adsorbable organic fraction of around 1.2 mg/L DOC. The three oxidation methods employed, electrolytic oxidation over a boron-doped diamond electrode, UVA/TiO2 photocatalysis and sonolysis at 80 kHz, showed similar behavior: during the first few minutes of treatment there was a moderate removal of DOC followed by further oxidation at a very slow rate. Electrolytic oxidation was capable of removing up to 36% at 17.8A after 30 min of treatment, sonolysis removed up to 34% at 135W after 60 min, while photocatalysis was capable of removing up to 50% at 60 min.     

New Treatment Processes for Pesticides and Chlorinated Organics Control in Drinking Water

Sources of pesticides and chlorinated organic compounds potentially found in water sources are reviewed. International and UK drinking water standards for these compounds are discussed and compared with concentrations found in ground and surface waters derived from lowland agricultural and urban areas.
Water soluble herbicides including triazines, phenylamides (urons) and chlorophenoxy acids are the most commonly reported types of pesticide compounds found above 0.1 μg/l in water sources. The more toxic, and less water soluble, organo-chlorine and organophosphorus pesticides are rarely reported.
Chlorinated organic solvents are reported as contaminants of some groundwaters. Disinfection by-products, in particular trihalomethanes, formed during the chlorination of waters containing natural organics, are widely reported, sometimes at concentrations above current UK standards.
The effects of conventional water-treatment processes on the concentrations of these organic compounds are discussed. Additional water-treatment processes, designed specifically for trace organic micropollutant removal, are identified and reviewed. Ozonation, activated-carbon adsorption and air stripping are acknowledged as appropriate advanced water-treatment process solutions. Developments in novel technologies include organics destruction via advanced oxidation processes, biological processes, membrane technology and novel adsorbents.
Thames Water Plc is contributing to research in this area, investing over £5 million in pilot- and large-scale trials prior to a £200-£300 million capital investment programme in advanced water treatment in the 1990s.     

Ozonation kinetics of cork-processing water in a bubble column reactor

The oxidative degradation of organic pollutants present in cork-processing water at natural pH (6.45) was studied in a bubble column ozonation reactor. A steady reduction in both chemical oxygen demand (COD) and total organic carbon (TOC) was observed under the action of ozone alone and the feasibility of deep mineralisation (organic matter removal more than 90% in 120 min under the following experimental conditions: liquid volume 9L; superficial gas velocity 6.8x10(-3) m s(-1); ozone partial pressure 1.31 kPa; initial COD 328 mg L(-1); initial TOC 127 mg L(-1)) was demonstrated. The monitoring of pH, redox potential (ORP) and the mean oxidation number of carbon (MOC) was correlated with the oxidation and mineralisation of the organic species in the water. The ozonation of cork-processing water in the bubble column was analysed in terms of a mole balance coupled with ozonation kinetics modelled by the two-film theory of mass transfer and chemical reaction. Under the experimental conditions used, and in contrast with the literature, it was determined that the reaction follows a fast kinetic regime at the beginning of the oxidation process, shifting to the moderate and the slow kinetic regimes at later stages of the oxidation reaction. The dynamic change of the rate coefficient estimated by the model was correlated to changes in the water composition.     

Iron(3) oxide-based nanoparticles as catalysts in advanced organic aqueous oxidation

Water contaminated with dissolved organic matter is an important issue to resolve for all-purpose uses. The catalytic behavior of iron-based nanocatalysts was investigated for the treatment of contaminated water in the advanced chemical oxidation process. In this study, typical organic contaminants, such as ethylene glycol and phenol, were chosen to simulate common contaminants. It was shown that the two substances are efficiently destroyed by the Fenton-like reaction using iron(3) oxide-based nanocatalysts in the presence of hydrogen peroxide without the need for UV or visible radiation sources at room temperature. A strong effect of nanocatalyst concentration on reaction rate was shown. The kinetic reaction was found and the reaction rate coefficient k was calculated.     

利用畜禽废水中的氨氮驯化矿化垃圾填料氧化填埋场的CH4

探讨通过利用畜禽废水中氨氮实现矿化垃圾中铵氧化菌的富集,再利用其对CH4同等氧化能力实现垃圾填埋场温室气体总量减排。研究结果表明：矿化垃圾对畜禽污水中氨氮具备较强的硝化能力,运行120 d内氨氮去除率高于60%;投加200 mg·kg -1氨氮后的培养研究中,120 h驯化后矿化垃圾硝酸盐氮的生成量分别为原生矿化垃圾样品和粘土样品的2.0倍和3.8倍;矿化垃圾和粘土样品中CH4消耗和CO2的净生成趋势可分别采用一级和零级动力学模型来表征(R 2>0.68);与氮转化趋势类似,基于CO2的净生成速率,120 d驯化后矿化垃圾的CH4氧化能力比粘土样和原生矿化垃圾分别提高了59.3%和10.6%。矿化垃圾经高氨氮畜禽养殖废水驯化可有望提高其对CH4的氧化能力,而污水中其他组分(CODCr、SS及磷素等)富集对CH4氧化过程的影响还亟待进一步研究。     

Phenol oxidation kinetics in water solution using iron(3)-oxide-based nano-catalysts

The influence of inorganic ions (HCO(3), PO(4)/HPO(4)/H(2)PO(4), Cl, SO(4), Ca, Na and Mg) on the advanced chemical oxidation process of organic compounds dissolved in water is reported here. The catalytic behavior of iron(3)-oxide-based nano-particles was investigated together with inorganic ions and hydrogen peroxide concentrations, and pH level. Phenol was chosen as a typical organic contaminant for this study as a simulating pollutant. The limiting concentrations of radical scavengers making the oxidation process inefficient were identified. The strong effect of concentration of radical scavengers HCO(3), PO(4)/HPO(4)/H(2)PO(4), the nano-catalyst and hydrogen peroxide concentrations, and pH on the phenol oxidation rate and lag time period before reaction starts was determined. It was shown that Cl, SO(4), Ca, Na and Mg ions had no significant effect on the kinetics of phenol oxidation.     

Review of photochemical reaction constants of organic micropollutants required for UV advanced oxidation processes in water

Emerging organic contaminants (pharmaceutical compounds, personal care products, pesticides, hormones, surfactants, fire retardants, fuel additives etc.) are increasingly found in water sources and therefore need to be controlled by water treatment technology. UV advanced oxidation technologies are often used as an effective barrier against organic contaminants. The combined operation of direct photolysis and reaction with hydroxyl radicals ensures good results for a wide range of contaminants. In this review, an overview is provided of the photochemical reaction parameters (quantum yield, molar absorption, OH radical reaction rate constant) of more than 100 organic micropollutants. These parameters allow for a prediction of organic contaminant removal by UV advanced oxidation systems. An example of contaminant degradation is elaborated for a simplified UV/H₂O₂ system.     

UV-based processes for reactive azo dye mineralization

In the present study, advanced oxidation processes, UV/H2O2, UV/O3, and UV/H2O2/O3 have been applied to bleach and degrade organic dye C.I. Reactive Red 45 in water solution. Influence of pH and hydrogen peroxide dosage on process efficiency was investigated. The rate of color removal was studied by measuring the absorbance at the characteristic wavelength while mineralization rates were obtained on the basis of total organic carbon (TOC) and adsorbable organic halides (AOX) measurements. Complete bleaching was achieved by all applied processes after 60 min while the maximal mineralization extent depended on the reaction conditions for each of the processes. It has been found that UV/H2O2/O3 process was the most efficient with 61.1% TOC removal and 72.0% AOX removal, respectively, achieved after a 1-h treatment. Time required for complete mineralization of RR45 by UV/H2O2 and UV/H2O2/O3 processes was determined as well.