含酚废水的生物处理方法及其进展

介绍了含酚废水的主要来源和危害,对常见含酚废水的生物处理方法的原理和特点进行了介绍,并阐述了这些方法近年来的研究进展,为开展含酚废水的污染防治研究工作提供了理论指导。     

含甲醇废水的生物处理实例

一体化两相厌氧反应器是最新研制的UASB型设备,并应用于武进精细化工厂高浓度含甲醇有机废水处理工程,运行过程表明,一体化两相厌氧反映器的处理效果十分显著,容积负菏达到6.0-11.0kgCOD/(m^3.d),进水COD达到6000mg/L以上,运行期间虽然进水负菏有很大波动,但出水COD值都在200-400mg/L之间。     

好氧流化床处理含酚废水的基本特性分析

本文通过试验测定,详细分析了生物流化床处理含酚废水的起动挂膜规律及运行过程特性。结果表明,无挂膜后驯化、逐段提高负荷、不断驯化的培养方法,有利于加快生物流化床的起动过程;生物流化床拥有的高生物浓度(最高达33g/L)及其拟完全混合流态,使其具有较宽的适应范围和较强的抗冲击能力。在本试验负荷范围(α≤41.0kg COD/m~3·d、α′≤15.05kg酚/m~3·d)内,COD平均去除率>80％,挥发酚平均去除率>90％,充分显示了生物流化床运行的经济性与稳定性。     

氯氧化处理含酚废水试验

选用次氯酸钠作氧化剂 ,研究了氧化剂投量、pH值及反应时间对处理效果的影响。试验结果表明 ,氧化剂最佳投量为 2 5 0mL L(有效氯为 5 .2 % ) ,最佳 pH =2～ 3,在此条件下反应 1h后对COD、对苯二酚和色度的去除率分别可达 89.8%、91.3%和 99%。     

固定化微生物技术处理含酚废水

采用经苯酚驯化后的活性污泥制成固定化微生物小球，处理了两种不同类型的含酚废水：对于苯酚浓度为2148．0mg/L、COD为10828．8mg/L的高浓度合酚废水，经24h处理后，对苯酚及COD去除率分别为50．1％和38．7％；对于苯酚浓度为180．7mg/L、COD为947mg/L左右的一般浓度混合合酚废水，经6h处理后对苯酚及比COD去除率分别为89．1％和84．6％，而活性污泥法分别为76．6％和75．0％。固定化微生物法的比COD去除率在废水比COD＜1500mg/L时保持稳定，而活性污泥法在比COD＜l000mg／L时保持稳定。固定化微生物法在处理时间及浓度两方面均优于活性污泥法。     

悬浮,附着厌氧—好氧生物处理新工艺的研究与应用

以印染废水为对象研究了悬浮、附着厌氧－好氧生物处理新工艺，提出了工艺设计运行参数，并论述了工艺特点，研究结果表明，此工艺流程简单，能耗低，效率高，易于推广。为污水生物处理开辟了一条新的途径。     

厌氧/好氧/生物脱氨工艺处理煤化工废水

采用厌氧/好氧/生物脱氨/混凝沉淀工艺处理煤化工废水,设计总处理量为360m3/h。4个多月的调试运行结果表明,该工艺运行稳定,耐冲击负荷能力强,当进水平均COD为2 141 mg/L、总酚为391 mg/L、氨氮为92 mg/L时,处理后出水COD100 mg/L、总酚10 mg/L、氨氮15 mg/L,出水水质达到《污水综合排放标准》(GB 8978—1996)的一级标准。     

废水厌氧生物处理的研究与进展

分析了污水厌氧生物处理技术发展沿革,介绍了厌氧生化基本原理及可行性,阐述了技术现状与研究进展,并总结出废水厌氧生物处理亟待解决的问题。     

城市废水厌氧生物处理的研究与实践

近三十多年来,环境污染及能源短缺的加剧,促进了厌氧生物处理的发展。一大批高效新型厌氧反应器的出现,使厌氧生物处理在高浓度有机工业废水的处理中,得到了日益广泛的应用,显示出了运行费用省、能量消耗少、能回收沼气能源等突出优点。八十年代中,不少国家进行了利用厌氧生物处理技术处理城市废水的试验研究,取得了十分令人振奋的成果。表明城市废水的厌氧生物处理,是一个值得注意的新方向、新途径。     

Factorial experimental design of winery wastewaters treatment by heterogeneous photo-Fenton process

Winery wastewaters are difficult to treat by conventional biological processes because they are seasonal and experience a substantial flow variations. Photocatalytic advanced oxidation is a promising technology for wastewaters containing high amounts of organic matter. In this work, the photo-Fenton process in heterogeneous phase is presented as an alternative methodology for the treatment of winery wastewaters. As a consequence of the great number of existing variables, an experimental design methodology has been used in order to study the influence and interaction of various variables and to obtain a reduced empirical model which describes the organic matter degradation process. Applying photo-Fenton treatment in heterogeneous phase under energetic conditions for synthetic samples simulating winery wastewaters results in purification levels of up to 50% (measured as total organic carbon). Different reduced models are obtained and their utilization depends mainly on the degree of degradation of organic matter required.     

环境温度下DASB预处理脱墨废水的研究

降流式厌氧污泥床反应器(DASB)作为一种新型厌氧处理工艺,具有生物截留能力强、泥水混合效果好、运行管理方便、性能可靠等优点。采用DASB对造纸脱墨废水进行预处理,研究了其影响因素和水解酸化效果。试验结果表明,pH值、HRT和容积负荷对DASB的运行效果有一定的影响,当出水pH值为7.0～7.2、HRT为22.4 h、容积负荷为2.15 kg/(m3.d)时,运行效果最好;在最佳运行条件下,当进水BOD5/COD值在0.38左右时,出水BOD5/COD值可提高到0.50左右,脱墨废水的可生化性大大提高。     

高浓度活性红染料废水处理初步研究

以模拟高浓度染料有机废水为研究对象,采用厌氧-好氧-活性炭吸附处理工艺进行了处理研究．结果表明,废水经12h厌氧处理,CODcr去除率为36．6％,BODs去除率为26．3％,色度去除率为83％;经好氧处理24h,CODcr,去除率为75．1％,色度去除率为85％;最后经活性炭吸附处理,出水符合综合废水一级排放标准．     

Solar treatment of cork boiling and bleaching wastewaters in a pilot plant

This paper reports on cork boiling and bleaching wastewaters treatment by solar photocatalytic processes, TiO₂/UV and Fe²⁺/H₂O₂/UV (TiO₂-only for bleaching wastewater), in a pilot plant with compound parabolic collectors. The photo-Fenton reaction (k = 0.12 L/kJ_UV, r₀ = 59.4 mg/kJ_UV) is much more efficient that TiO₂ photocatalysis and TiO₂ + S₂O₈²⁻ (k = 0.0024 L/kJ_UV, r₀ = 1.36 mg/kJ_UV), leading to 94% mineralization of the bleaching wastewater after 31.5 kJ_UV/L, consuming 77.1 mM of H₂O₂ (3.0 mmol/kJ_UV) and using 20 mg/L of iron. For the cork boiling wastewater, after a slow initial reaction rate, the DOC degradation curve shows a first-order kinetics behaviour (k = 0.015 L/kJ_UV, r₀ = 20.8 mg/kJ_UV) until 173 kJ_UV/L (≈300 mg C/L). According to the average oxidation state (AOS), toxicity profiles, respirometry and kinetic results obtained in two solar CPCs plants, the optimal energy dose estimated for phototreatment to reach a biodegradable effluent is 15 kJ_UV/L and 114 kJ_UV/L, consuming 33 mM and 151 mM of H₂OT:/PGN/ELSEVIER/WR/web/00007490/₂, achieving almost 49% and 48% mineralization of the wastewaters, respectively for the cork bleaching and boiling wastewaters.     

Determination of low concentration of sulphorhodamine B in wastewaters and stabilization ponds

The use of sulphorhodamine B, a known red fluorescent dye as a quantitative tracer in hydrological studies related to wastewaters has been proved experimentally. The interference in the accuracy of fluorescence readings owing to dissolved or suspended contaminants in wastewaters, especially at low concentrations of dye, was solved by successive filtering and eluting of the sample through a sep-pack C-18. The sulphorhodamine B, which is concentrated by displacement with small volumes of methanol, was thus retained. Volumes were then read with an fluorescence spectrophotometer. The procedure was demonstrated to be valid for use with sewers, stabilization ponds and wastewaters for concentrations as low as 5 × 10⁻⁷ g litre⁻¹.     

Purification of cork processing wastewaters by ozone,by activated sludge,and by their two sequential applications

Wastewaters generated in the cork processing industry were treated in continuous reactors by means of single treatments separately-a chemical ozonation and an activated sludge system-and then by both sequential processes-ozonation followed by aerobic degradation, and aerobic degradation followed by ozonation. The removals obtained in the ozonation alone were 12-54%, 65-81%, and 55-89% for the COD, total phenolics, and absorbance at 254 nm, respectively, while the consumed ozone yield ranged from 40% to 61%, and the biodegradability (BOD(5)/COD) varied from an initial 0.60 to final values between 0.68 and 0.93. The optimum hydraulic retention time and ozone partial pressure were 3 h and 3 kPa, respectively. The stoichiometric ratio was 0.56 g of organic substrate degraded per g of ozone consumed, while the rate constants obtained for the ozone disappearance and for the organic matter degradation were 4490 L g COD(-1) h(-1) and 1970 L g O(3)(-1)h(-1) respectively. The presence of hydrogen peroxide or UV radiation in addition to ozone increased the values of organic matter removal as well as the stoichiometric ratio and the rate constants. The aerobic treatment by the activated sludge system yielded COD removals between 13% and 37% for hydraulic retention times between 24 and 96 h, and the Contois model gave values of q(max)=0.14 g COD g VSS(-1)h(-1) and K(1)=22.6 g COD g VSS(-1) for the main kinetic parameters. The sequential processes increased the substrate removal efficiencies in comparison with the individual processes. These enhancements were greater in the aerobic degradation-ozonation sequence than in the ozonation-aerobic degradation sequence.     

Prevention of volatile fatty acids production and limitation of odours from winery wastewaters by denitrification

The effect of the addition of nitrate to winery wastewaters to control the formation of VFA in order to prevent odours during storage and treatment was studied in batch bioreactors at different NO(3)/chemical oxygen demand (COD) ratios and at full scale in natural evaporation ponds (2 x 7000 m(2)) by measuring olfactory intensity. In the absence of nitrate, butyric acid (2304 mgL(-1)), acetic acid (1633 mgL(-1)), propionic acid (1558 mgL(-1)), caproic acid (499 mgL(-1)) and valeric acid (298 mgL(-1)) were produced from reconstituted winery wastewater. For a ratio of NO(3)/COD=0.4 gg(-1), caproic and valeric acids were not formed. The production of butyric and propionic acids was reduced by 93.3% and 72.5%, respectively, at a ratio of NO(3)/COD=0.8, and by 97.4% and 100% at a ratio of NO(3)/COD=1.2 gg(-1). Nitrate delayed and decreased butyric acid formation in relation to the oxidoreduction potential. Studies in ponds showed that the addition of concentrated calcium nitrate (NITCAL) to winery wastewaters (3526 m(3)) in a ratio of NO(3)/COD=0.8 inhibited VFA production, with COD elimination (94%) and total nitrate degradation, and no final nitrite accumulation. On the contrary, in ponds not treated with nitrate, malodorous VFA (from propionic to heptano?c acids) represented up to 60% of the COD. Olfactory intensity measurements in relation to the butanol scale of VFA solutions and the ponds revealed the pervasive role of VFA in the odour of the untreated pond as well as the clear decrease in the intensity and not unpleasant odour of the winery wastewater pond enriched in nitrates. The results obtained at full scale underscored the feasibility and safety of the calcium nitrate treatment as opposed to concentrated nitric acid.     

Separation of the propionate degradation to improve the efficiency of thermophilic anaerobic treatment of acidified wastewaters

The degradation of propionate generally is limiting in the thermophilic methane digestion of acidified wastewaters. In this paper the propionate degradation in thermophilic systems is studied. A two-stage process is developed, in which the propionate degradation is spatially separated from other conversions in which hydrogen is involved. Significantly better results were obtained with the two-stage system as compared with a one-stage system with an equal total volume: loading rates of 20–50 kg COD m⁻³ day⁻¹ showed a 10–13% better treatment efficiency in the two-stage system. It is concluded that the removal of the biogas evolved in the first degradation processes is the cause of the superior performance of the two-stage system.     

Effect of textile wastewaters on Saccharomyces cerevisiae using DNA microarray as a tool for genome-wide transcriptomics analysis

Textile mill effluents (TMEs) discharged from the textile industry can be considered as one class of hypothetical toxicants in the environment. To investigate the potential toxicity of TMEs, we applied cDNA microarray technology to examine the genome-wide expression profiles in model eukaryote, Saccharomyces cerevisiae. The results revealed a rich source of genetic information for the yeast cells that were exposed to the untreated and treated TMEs. Among the 5956 valid genes, 275 genes were up-regulated and 40 genes were down-regulated for the untreated TMEs. On the other hand, only 90 genes were up-regulated, and 29 genes were down-regulated upon exposure to the treated TMEs. The changes in gene expression were also confirmed by RT-PCR. The potent up- and down-regulation of genes suggest that yeast cells undergo genome-wide changes in mRNA expression, indicative of a stress response. Additionally, a classification into specific functional gene categories indicated that untreated and even treated TMEs still had toxicity. Especially, the genes related to oxidative stress, such as AHP1, ATX1, GRX1, TRX1 and TRX2, were up-regulated in treated TMEs that can directly reach to surface and ground waters, and sediments.     

环氧树脂改性甲酚副产物合成酚醛树脂胶黏剂的研究

甲酚作为重要的精细化工的原料在医药等诸多领域得到广泛的应用,但产生大量对环境造成污染的甲酚生产副产物。本研究应用环氧树脂来改性甲酚副产物合成的酚醛树脂胶黏剂,以胶黏剂的粘结性能为评价标准,探讨了改性胶黏剂性能影响因素。结果表明,在合适的原料配比和反应条件下,可以制备性能合格的胶黏剂产品。