Integration of chemical and biological oxidation in a SBBR for tannery wastewater treatment.

This paper reports the results of an investigation aimed at evaluating the laboratory-scale performance of an innovative process for treating tannery wastewater. In this process, biological degradation, carried out in a sequencing batch biofilm reactor (SBBR), is combined with chemical oxidation by ozone. Tannery wastewater treatment was carried out, at laboratory scale, on a real primary effluent coming from a centralised plant treating wastewater produced by a large tannery district in Northern Italy. SBBR performance both without and with ozonation, was assessed with very satisfactory results. In particular, in the latter instance the recorded COD, TKN and TSS average removals, (96%), (92%) and (98%) respectively, allowed the maximum allowable concentration values fixed by the Italian regulation in force to be achieved without any additional polishing step. During the investigation biofilm properties (biofilm concentration and biofilm density) and flow dynamics aspects (head loss, shear stress, bed porosity) were also studied. A major feature of the process is that, with or without ozonation, it was characterised by very low specific sludge production (0.05 kgVSS/kgCODremoved) and high biofilm density (i.e. 87-122 gVSS/Lsludge) both contributing to a rather high biofilm concentration (i.e. 31-44 gTSS/Lfilter).     

兼氧—深曝—接触氧化工艺处理制药废水

某制药厂生产废水CODCr高,成分复杂,水质混浊,pH变化大,有颜色和异味,且含有难生物降解和有抑菌作用的抗菌素等毒性物质.针对以上情况,采用兼氧-深曝-接触氧化工艺处理该制药废水.经过3个月调试监测结果表明:处理后BOD5、CODCr、NH3-N和SS的去除率分别为99%、98.5%、85%和98%,出水各项指标符合<污水综合排放标准>(GB 8978-1996)一级排放标准.     

Phenol wastewater remediation: advanced oxidation processes coupled to a biological treatment.

Nowadays, there are increasingly stringent regulations requiring more and more treatment of industrial effluents to generate product waters which could be easily reused or disposed of to the environment without any harmful effects. Therefore, different advanced oxidation processes were investigated as suitable precursors for the biological treatment of industrial effluents containing phenol. Wet air oxidation and Fenton process were tested batch wise, while catalytic wet air oxidation and H2O2-promoted catalytic wet air oxidation processes were studied in a trickle bed reactor, the last two using over activated carbon as catalyst. Effluent characterisation was made by means of substrate conversion (using high liquid performance chromatography), chemical oxygen demand and total organic carbon. Biodegradation parameters (i.e. maximum oxygen uptake rate and oxygen consumption) were obtained from respirometric tests using activated sludge from an urban biological wastewater treatment plant (WWTP). The main goal was to find the proper conditions in terms of biodegradability enhancement, so that these phenolic effluents could be successfully treated in an urban biological WWTP. Results show promising research ways for the development of efficient coupled processes for the treatment of wastewater containing toxic or biologically non-degradable compounds.     

湿式氧化技术处理化工废水的研究

采用湿式氧化技术处理在生产磺胺间二甲氧嘧啶过程中产生的高浓度有机废水。在反应温度为250℃,初始ρ(COD)为4 575 mg/L,反应时间为2 h,pH值为7~8时,采用湿式双氧水氧化和催化湿式氧化,COD去除率分别为78.3%和92.0%,表明催化湿式氧化具有较好的COD去除效果。同时考察了催化湿式氧化中反应温度、反应时间、废水pH值对COD去除率的影响。     

A modified advanced Fenton process for industrial wastewater treatment.

For the first time hydrodynamic cavitation induced by a liquid whistle reactor (LWR) has been used in conjunction with the advanced Fenton process (AFP) for the treatment of industrial wastewater. Semi-batch experiments in the LWR were designed to investigate the performance of the process by optimising various parameters such as pressure, pH, H2O2 concentration and the concentration of industrial wastewater samples on the mineralisation of the total organic carbon (TOC). It was found that higher pressures are more favourable for a rapid TOC mineralisation.     

水解酸化-SBR-接触氧化法处理制药废水

采用水解酸化-SBR-接触氧化工艺处理制药厂生产过程中产生的丁提废水和虫草废水,处理水量2000 m3/d,进水CODCr约4000 mg/L.监测结果表明,处理后BOD5、CODCr和SS的去除率分别为98.5%、93%和80%,出水BOD5、CODCr和SS分别为28.3～30 mg/L、145.6～285.7mg/L和23.6～27.2 mg/L,出水各项指标符合<污水综合排放标准>(GB 8978-1996)二级标准.实际运行显示,该工艺处理效果稳定,耐冲击负荷性强.     

铁炭微电解-Fenton试剂氧化-二级A/O工艺处理化工废水工程实例

采用铁炭微电解结合Fenton试剂的化学氧化做预处理,二级A/O结合PACT工艺做后处理,混凝沉淀做辅助处理工艺处理含硝基苯的化工废水。介绍了工艺流程、主要参数和运行效果,同时讨论了该工艺的影响因素。工程监测结果表明:设计进水水量为600im~3/d,COD为5000mg/L时,预处理出水COD降至约1500mg/L,BOD/COD从0.1上升到0.3以上,后处理出水COD约为150mg/L,辅助处理出水COD小于100mg/L,COD总去除率可达97％。该工艺根据废水呈酸性的特点并合理利用废铁刨花,具有以废治废的特点,处理效果好,成本低,操作维护方便。     

UNITANK工艺深度处理漂染废水

介绍UNITANK工艺深度处理漂染废水的效果,并探讨UNITANK工艺运行规律、HRT及水质变化等对处理效果的影响.结果表明,在中等有机负荷下,HRT 6 h,中间池DO为1.5～2 mg/L、边池DO为2 mg/L的条件下,处理效果较佳且稳定.经济方面也具有一定优势.     

Comparison of different advanced oxidation process to reduce toxicity and mineralisation of tannery wastewater.

Many organic compounds contained in wastewater are resistant to conventional chemical and/or biological treatment. Because of this reason different degradation techniques are studied as an alternative to biological and classical physico-chemical processes. Advanced Oxidation Processes (AOPs) probably have developed to become the best options in the near future. AOP while making use of different reaction systems, are all characterised by the same chemical feature: production of OH radicals (*OH). The versatility of AOPs is also enhanced by the fact that they offer different possibilities for OH radical production, thus allowing them to conform to specific treatment requirements. The main problem with AOPs is their high cost. The application of solar technologies to these processes could help to diminish that problem by reducing the energy consumption required for generating UV radiation. In this work, different AOPs (O3, TiO2/UV, Fenton and H2O2/UV) were examined to treat tannery wastewater or as a pre-treatment step for improving the biodegradation of tannery wastewater, at different pH and dosage of the chemicals. Under certain circumstances retardation in biodegradation and/or an increase in toxicity may be observed within these treatment steps. Two different bioassays (Daphnia magna and Vibrio fischeri) have been used for testing the progress of toxicity during the treatment. In parallel other objectives were to analyse and identify organic compounds present in the untreated wastewater and arising degradation products in AOP treated wastewater samples. For this purpose substance specific techniques, e.g., gas chromatography-mass spectrometry (GC-MS) in positive electron impact (El(+)) mode and atmospheric pressure ionisation (API) in combination with flow injection analysis (FIA) or liquid chromatography-mass and tandem mass spectrometry (LC-MS or LC-MS-MS) were performed.     

臭氧高级氧化技术深度处理印染废水试验研究

研究单独臭氧氧化、O3/H2O2、O3/非均相催化臭氧化技术对去除难降解染料废水CODcr、色度、UV254和提高可生化性的效果。实验结果表明:印染废水最适宜的深度处理方法是O3/MnOx-GAC。当O3投加量为81mg/L时,O3/MnOx-GAC对CODcr、色度和UV254的去除率分别为36.23%、70%和60.67%,B/C由原来的0.1上升到0.26,可采用后续生化处理进一步去除有机物。     

Fenton氧化深度处理柠檬酸生产废水

采用Fenton氧化深度处理柠檬酸废水通过正交试验和单因素轮换试验,分析pH、H_2O_2投加量、反应时间、H_2O_2/FeSO_4四个主要因素对COD_(Cr)去除效果的影响。试验结果表明影响效果从大到小依次为pHH_2O_2/FeSO_4反应时间H_2O_2投加量,单因素试验确定最佳的反应条件为:pH为3.5、反应时间为2 h、30%H_2O_2投加量0.9 mL/L,FeSO_4用量为223.4 mg/L,此条件下COD_(Cr)去除率达到约75%。氧化去除COD_(Cr)过程符合准一级反应,表观速率常数0.012 9 min~(-1),设计连续流全混反应器中停留时间为2 h。在最佳药剂投加量下,中试连续运行出水COD_(Cr)40 mg/L,实际出水COD_(Cr)与理论拟合值接近。     

Treatment of non-biodegradable cutting oil wastewater by ultrasonication-Fenton oxidation process.

To treat cutting oil wastewater produced in metal surface treatment industry, Ultrasonication (US)-Fenton process, which is one of the advanced oxidation processes, was used. The optimum conditions to treat non-biodegradable pollutants using the US-Fenton process were that the application rates of H2O2 and FeSO4 were 10% and 3 g/L, respectively, the value of pH was 3, and the ultrasonication time was 30 min. It identified non-degradable pollutants such as ethylene diamine tetraacetic acid (EDTA) and Triethanolamine (TEA) in the cutting oil wastewater. TLC analysis of two compounds of treated water by the coagulation process was similar to that of raw water. However, TLC analysis of two compounds of US-Fenton process was different from that of raw water, meaning that US-Fenton process decomposed the EDTA and TEA. To study the possibility of application with the US-Fenton process to pilot plant, the pollutants treatment efficiency of three different methods, such as US-Fenton process, activated sludge process and coagulation process, in continuous experiments were compared. The removal rate of pollutants by the US-Fenton process according to the effluent time was higher than any other processes. The removal rates of COD, SS, T-N and T-P by US-Fenton process were 98, 93, 75 and 95%, respectively.     

UASB-水解酸化-接触氧化工艺处理阿维菌素废水

采用UASB-水解酸化-接触氧化法处理阿维菌素废水,其中高浓度废水直接采用UASB处理,出水和综合废水混合经水解酸化后利用接触氧化法进行处理,系统处理效率高,运行稳定,CODCr去除率为97%,出水水质达到<污水综合排放标准>(GB 8978-1996)二级标准.     

Sensor fault diagnosis in a wastewater treatment process.

There are many sensors in a wastewater treatment process (WWTP) plant for monitoring process performance and condition. Sensor validation is essential to the success of process monitoring. In this paper, various sensor faults which can occur in WWTP are identified for taking proper remedial action at an early time. A proposed sensor fault isolation method is based on the variable reconstruction using principal component analysis (PCA). Even though several methods have been developed to identify sensor faults, they are only applicable to a static process. In other words, they cannot be successfully used to monitor severe dynamic processes such as WWTPs. We have removed this limitation by developing reconstruction methods based on a dynamic version of PCA. Artificial scenarios of sensor faults generated from the simulation benchmark have been used to validate the proposed sensor identifying methodology. Also, it is compared to a previous method to show its relative superiority in sensor fault validation in the WWTP.     

Oxidative degradation of chemical warfare agents in water by bleaching powder

Degradation of sulfur mustard (HD), S-2-(di-isopropylamino)ethyl O-ethyl methylphosphonothioate (VX) and Soman (GD) in water by bleaching powder was investigated. The degradation products were comprehensively analyzed by gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS) and ion chromatography. Degradation pathways were deduced based on the identified products. The product analysis results indicated that HD could be degraded through oxidation and chlorination reactions, and a small portion of sulfur atoms could be mineralized into SO(4)(2-) ion. Oxidative degradation of VX could finally generate O-ethyl methylphosphonate acid (EMPA), sulfonic acids, SO(4)(2-) and NO(3)(-) ions. GD would be converted into non-toxic pinacolyl methylphosphonate via nucleophilic substitution.     

空气曝气与纯氧曝气生物滤池应用于污水深度处理的研究

采用两种不同气源的曝气生物滤池对污水处理厂二级出水进行深度处理中试研究.结果表明,空气曝气和纯氧曝气生物滤池对COD_(Mn)的去除率相近,分别为30.5%和30.9%;以纯氧为气源的生物滤池硝化能力远强于空气曝气生物滤池,氨氮总去除率77.4%,出水氨氮为2.1～6.3 mg/L;纯氧曝气提高了滤池上部氨氮去除效果,维持滤池内溶解氧在6 mg/L以上,沿水流方向使pH逐渐下降.纯氧曝气生物滤池是污水深度处理中去除氨氮的有效工艺.     

化学复合破乳剂处理冷轧乳化液废水的试验研究

探讨了不同条件下,利用自制化学复合破乳剂处理冷轧乳化液废水的试验效果。结果表明:用MgSO4 Al2(SO4)3 阳离子型PAM处理冷轧乳化液废水,能使其COD从6.064×104mg/L降至2 187 mg/L,COD去除率可达97％,并且具有工艺设备简单,动力消耗和综合水处理成本低的特点。     

铁碳微电解——ABR——接触氧化工艺处理糠醛废水

糠醛废水是一种高浓度难处理的有机废水,介绍了铁碳微电解—ABR—接触氧化工艺在实际工程中处理糠醛废水的启动与运行。结果表明,该工艺对CODCr、BOD5、SS等污染物的去除效果较好,同时指出工程在启动运行中存在的一些问题。     

UASB-接触氧化工艺处理黄酒废水工程实例

结合工程实例,介绍了UASB-接触氧化工艺处理黄酒废水的主要工艺设计参数,调试运行过程;分析了调试运行过程中出现各种现象的原因;总结了设计运行过程中的经验和教训.     

Fenton氧化法深度处理制革废水生化出水试验研究

采用Fenton氧化法深度处理以制革废水为主的园区生化处理出水,试验表明:影响Fenton氧化的因素从大到小依次为H2O2投加量、Fe2+浓度、pH、反应时间。当进水CODCr平均为116.6mg/L时,在H2O2投加量50mmol/L、Fe2+投加量10mmol/L、pH为3、反应时间60min的最佳条件下,出水CODCr平均为31.7mg/L;在H2O2投加量25mmol/L、Fe2+投加量7.5mmol/L、pH为5、反应时间40min的经济运行条件下,出水CODCr平均为46.6mg/L。经济条件下的运行成本比最佳条件下的运行成本可节约2.3元/m3。