A/A/O工艺对焦化废水的处理效果研究

厌氧/缺氧/好氧(A/A/O)工艺是典型行业废水-焦化废水的常用处理工艺。但该工艺过程对焦化废水生物毒性的去除规律还缺少研究。研究以大型溞为受试生物,考察了焦化废水的毒性特征随A/A/O工艺的变化规律。结果表明,厌氧池对急性毒性的去除作用最大,好氧池对氧化损伤毒性去除作用较大。A/A/O工艺有效去除了焦化废水对大型溞的急性毒性,但对氧化损伤的去除效果稍差。     

A/A/O工艺对焦化废水生物毒性削减效果评价

厌氧-缺氧-好氧(A/A/O)工艺是目前常用的焦化废水处理工艺。但是关于该工艺过程对焦化废水生物毒性的去除情况还缺乏研究。研究考察了焦化废水对斑马鱼的生物毒性(急性毒性、氧化损伤毒性和遗传毒性)随A/A/O处理过程的变化规律。结果表明,A/A/O工艺有效地去除了焦化废水对斑马鱼的急性毒性,但对氧化损伤和遗传毒性的去除效果稍差;厌氧池对急性毒性的去除作用最大,缺氧池对氧化损伤毒性和遗传毒性的去除效果较好。     

A2/O工艺处理焦化废水实例

焦化废水水质复杂,COD、氨氮浓度高,给污水处理站运行带来很大困难。本文通过大量工艺指标,对A2/O工艺处理焦化废水中的影响因素和操作要点进行了分析和探讨,旨在为A2/O工艺处理焦化废水提供更多的参考和帮助。     

多相光催化氧化处理焦化废水的研究

以TiO2为催化剂,H2O2为氧化剂,在紫外光照射下采用多相光催化氧化法对焦化废水进行处理,探讨了影响COD去除率的各种因素,得出了最佳工艺条件。结果表明该法可使焦化厂二沉池废水COD从350.3mg/L降至53.1mg/L,COD去除率可达84.8%。还发现多相光催化氧化工艺并不适合处理高浓度废水,但通过提高H2O2的投加量可扩大多相光催化氧化法处理焦化废水的浓度范围。     

高效微生物法处理焦化废水工程实例

焦化生产中产生的高氯氮、高COD废水,采用常规生化处理工艺难以处理达标,采用高效微生物 A/O工艺取得好的处理效果,达到国家排放标准.本文描述了高效微生物法处理焦化废水工程的实例,为焦化废水的处理提供了实际数据参照.     

焦化废水A/O2和A/O/H/O处理工艺中多环芳烃的削减行为分析

多环芳烃(PAHs)是焦化废水的特征污染物,不同的焦化废水处理工艺会影响其归趋行为与削减量.基于此,本文追踪了焦化废水厌氧/好氧/好氧(A/O~2)和厌氧/好氧/水解/好氧(A/O/H/O)处理工艺中PAHs的分布行为,使用气质联用色谱(GC-MS)检测并分析了两种工艺中各单元反应器内废水及污泥样品的PAHs浓度,通过通量衡算,评估工艺系统处理效果的差异性.结果表明,两种工艺的前置A厌氧池对PAHs的削减不明显,PAHs在A池富集的浓度远高于O池及H池,低环PAHs经水相从A池进到O池后得到有效降解,高环PAHs则大部分富集于污泥相中,风险比较大,应该区别处理;A/O/H/O工艺对低环的PAHs生物削减率略高于A/O~2工艺,对4环以上的PAHs,A/O/H/O则表现出更明显的降解有效性,理解为A/O/H/O工艺的H池促进了大分子有机物的水解,对PAHs具有针对性.综合研究结果认为,A/O/H/O工艺表现出比A/O~2更明显的降解PAHs的优势.     

焦化废水污染特征及其控制过程与策略分析

针对量大面广、成分复杂、具有典型的有毒/难降解工业有机废水特征的焦化废水,介绍了不同生产工艺的水质水量、污染物组成、有机污染物的生物降解特性及基于其特性的废水处理方法的选择;重点分析了以脱氮为目标的A/O、A2/O、A/O2、O/A/O工艺的特点,强调了生物流化床反应器的高效性;从溶解氧、温度、pH值、营养组成、污泥龄及有毒有害物质调控等方面讨论了焦化废水污染控制过程的影响因素,比较了不同工程工艺的技术特点与经济差异,对一些敏感性指标提出了控制策略,强调了技术创新与政策性补偿有助于解决行业环保问题的观点.     

铁屑/焦炭/H_2O_2法预处理焦化废水的试验研究

采用铁屑/焦炭/H2O2法对焦化废水进行处理,通过单因素试验法考察了铁炭比、铁炭用量、H2O2用量、废水pH以及反应时间对处理效果的影响,并确定了最适工艺条件。结果表明,铁屑/焦炭/H2O2法与常规的铁屑内电解法相比,可显著提高焦化废水的预处理效果,并缩短反应时间。铁屑/焦炭/H2O2法处理焦化废水的最适条件为:铁炭比为4,铁炭用量为300mg/L铁屑+75mg/L焦炭,H2O2用量为1000mg/L,pH为3,反应时间20min。在此条件下,COD、色度、NH3-N和CN-的去除效率分别可达61.2%、74.0%、56.2%和74.3%,B/C比由处理前的0.189提高到0.387,处理水可生化性良好。铁屑/焦炭/H2O2可作为焦化废水的一种有效的预处理方法。     

厌氧—兼氧—好氧(A-A/O)系统处理焦化废水的研究

在实验室条件下,研究连续流厌氧-兼氧-好氧系统处理焦化废水性能.试验研究表明:A-A/O系统在去除焦化废水中的CODCr,、NH3-N方面效果明显.当进水pH控制在7.0～8.0,好氧反应器pH控制在6.7～7.0,温度控制在30℃,混合液回流比为4～5,系统总水力停留时间(HRT)为62 h时,系统对CODCr、NH3-N、酚和SCN-的去除率分别可达88%、90%、99%、88%.系统出水中的CODCr、NH3-N、酚浓度基本达到国家排放标准.     

气浮-A~2/O~2工艺处理焦化废水

以玉田县古玉煤焦化工有限公司焦化废水处理站工程为例,介绍气浮-A2/O2工艺处理高浓度焦化废水的运行效果及工艺参数。运行结果表明:气浮-A2/O2工艺对焦化废水具有理想的处理效果,当进水ρ(COD)<3 500 mg/L、ρ(酚)<700 mg/L、ρ(氰化物)<20 mg/L、ρ(NH3-N)<300 mg/L时,出水ρ(COD)<100 mg/L、ρ(酚)<0.5mg/L、ρ(氰化物)<0.5 mg/L、ρ(NH3-N)<15 mg/L,各项指标均达设计要求,满足熄焦工段的用水要求和排放标准。     

A2/O工艺处理城市污水的应用研究

介绍了A2/O脱氮除磷工艺处理城市污水的机理、特点及存在问题。根据污水处理厂的实际运行情况,分析了影响A2/O工艺的因素,采取了提高除磷效果的一些措施。实践表明这些措施对提高除磷效果具有明显作用。     

生物膜A/O法处理PTA废水的试验研究

在含两级Ａ／Ｏ和生物炭的连续运行试验装置上处理ＰＴＡ废水,结果表明：进水ＣＯＤｃｒ为１１０１ｍｇ／Ｌ,ＨＲＴ为４０ｈ,Ｏ２段和生物炭出水中残余ＣＯＤｃｒ分别为８２ｍｇ／Ｌ和５５ｍｇ／Ｌ,相应ＣＯＤｃｒ去除率分别为９２％和９５％;进水ＣＯＤｃｒ为１１１２ｍｇ／Ｌ,ＨＲＴ为３２ｈ,Ｏ２段和生物炭出水中残余ＣＯＤｃｒ分别为８６ｍｇ／Ｌ和６４ｍｇ／Ｌ,其去除率分别为９２％和９５％;在上述试验条件下刀;段ＴＡ去除率均为９３％。     

UV-catalytic treatment of spent caustic from ethene plant with hydrogen peroxide and ozone oxidation

The performance of UV/H2O2, UV/O3 and UV/H2O2/O3 oxidation systems for treating spent caustic from an ethylene plant was investigated, in UV/H2O2 system, with the increase of H202 dosage, removal efficiencies of COD and the ratio of biochemical oxygen demand(BOD) to chemical oxygen demand(COD) of the effluent were increased and a better performance was obtained than the H2O2 system alone. In UV/H2O2 system, removal efficiency of COD reach 68% under the optimum condition, and BOD/COD ratio was significantly increased from 0.22 to 0.52. In UV/O3 system, with the increase of O3 dosage, removal efficiency of COD and BOD/COD ratio were increased, and a better performance was obtained than the O3 system alone. Under the optimum condition, removal efficiency of COD was 54%, and BOD/COD ratio was significantly increased from 0.22 to 0.48. In UV/H2O2/O3 system, COD removal efficiency was found to be 22.0% higher than UV/O3 system.     

A~2O-MBR工艺的脱氮除磷特性研究

将传统的脱氮除磷工艺(厌氧/缺氧/好氧,A2O)与膜分离技术相结合,构建具有强化脱氮除磷作用的A2O-MBR工艺。以某城市污水处理厂的A2O-MBR工程为研究对象,通过长期的跟踪监测和实验研究,结果表明,该工艺具有非常好的脱氮除磷效果,出水总氮、氨氮及总磷的平均浓度分别为5.69 mg/L、1.32 mg/L和0.18 mg/L,去除率分别达到85%、94%和97%,优于《城镇污水处理厂污染物排放标准》中的一级A标准。另外,硝化速率随温度的降低而降低。释磷/吸磷效果较好,趋势明显。     

Recovery of a power plant cooling reservoir ecosystem from selenium bioaccumulation

Hyco Reservoir, a North Carolina power plant cooling impoundment, was impacted by selenium toxicity during the late 1970s. Selenium inputs via coal ash discharge resulted in bioaccumulation through the aquatic food chain which caused reproductive failure and population declines of bluegill, other Lepomis spp., largemouth bass, crappie, yellow perch, and sucker species. Following these declines, green sunfish, satinfin shiner, gizzard shad, eastern mosquitofish, and redbelly tilapia dominated the fish community. During 1990, the power plant converted to a dry fly ash handling system that reduced selenium loading into the reservoir. Construction costs for this system were approximately $48 million and annual operating costs have been approximately $1 million/year. Mean selenium concentrations in reservoir waters at the power plant discharge declined from 8.8 μg/l to 3.2 μg/l within one year of the system operation, and this decline was consistent with a priori mass balance modeling predictions. Depuration of selenium from sediments and tissues of plankton, benthos, and fish has been variable since the system operation. Significant selenium declines have occurred in tissues of aquatic organisms in the eight-year recovery period while little change has been observed in sediments. Recovery of the fish community has been rapid, particularly in areas upstream of the ash pond discharge, and confirmed population-level modeling predictions using a Leslie-matrix demographic model. Diversity of the fish community increased throughout the reservoir and species dominance shifted from a green sunfish and satinfin shiner-dominated system to a bluegill-dominated system within five years after the system operation. Increased bluegill and green sunfish hybridism also occurred during early recovery and coincided with a low abundance of spawning bluegill adults. Sport fisheries have re-developed for largemouth bass and crappie and strategies for managing the recovering fishery have included periodic stock assessments, creel surveys and harvest restrictions, prey fish stocking, and continued contaminant monitoring. This pollution abatement system has been successful in reducing selenium loading into the reservoir and prompting recovery of the aquatic ecosystem.     

苗期玉米、大豆在土壤-植物系统N2O排放中的贡献

为区分植物在土壤-植物系统N₂O排放中的贡献,用封闭式箱法对在温室内砂培和土培的玉米、大豆幼苗及砂、土、砂-植物系统、土壤-植物系统的N2O排放进行了测定,同时对植物N₂O排放与植物叶片中的硝酸还原酶(NR)活性及NO₃^--N、NO₂^--N含量的关系进行了分析.结果表明:在53d的观测期内,玉米、大豆幼苗本身均可排放N₂O,且在土壤(砂)-植物系统的N₂O排放中占有很大份额(79.18%～100%);植物N₂O的排放与植物叶片的硝酸还原酶活性和NO₃^--N、NO₂^--N的含量显著正相关(R²≥0.97,n=6).     

膜法A／O工艺处理炼油污水的探讨

应用生物膜法Ａ／Ｏ系统这项新技术处理炼油废水近三年来，已取得了初步成果；它对ＣＯＤ、酚、硫化物、ＮＨ３－Ｎ的去除效果明显，但对总氮的去除效果较差。对我厂Ａ／Ｏ系统的运行进行了分析，对其存在问题进行了探讨，且提出了可行性的建议。     

旁路化学除磷对A^2／O工艺脱氮除磷效果影响研究

本试验在A^2／O工艺中接入旁路化学除磷池,以考察旁路化学除磷对常规A^2／O工艺系统脱氮除磷效果的影响。研究结果表明,增加化学除磷池后的A^2／O工艺系统与常规A^2／O工艺系统相比,TN去除率提高了4．07％,TP去除率提高了2．23％,说明旁路化学除磷对常规A^2／O工艺系统脱氮除磷效果具有一定的改善作用。     

污水处理厂升级改造中氨氮控制工艺的研究

文章研究"生物膜+活性污泥"复合工艺,将生物膜法与传统的A2/O污水处理脱氮工艺结合起来,形成了"生物膜+A2/O"复合工艺。2种工艺有机地融合于一个反应系统中,既节省用地又延长污泥龄,使脱氮除磷的效果大大提高。用该工艺处理城市污水,其出水水质符合《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A标准,用作景观用水和一般回用水,可广泛地应用于污水处理厂的升级改造。     

浙江省污水污泥处理处置状况的调查

通过对丽水、宁波、衢州、诸暨等浙江省境内十几个地区的污水处理厂的调查发现:目前浙江省内的污水处理工艺中,A2/O、A/O、氧化沟三种工艺占了近50%的份额。而SBR因其方法特点正在受到越来越多的重视。在污泥处理工艺中,填埋占了最大的一部分,有近70%的污水处理厂将产生的污泥进行填埋处理。目前,污泥处理技术单一,需要继续探寻污泥的减量和资源化技术,为日益增多的污泥探寻出路。