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721.
722.
概述了蚯蚓生态滤池的研究进展,介绍了蚯蚓生态滤池化学除磷的工艺流程和设备参数;由试验得出氯化铁(FeCl3·6H2O)是蚯蚓生态滤池化学除磷的合适药剂,并确定最经济投加量为50mg/L;在此条件下,研究了化学除磷小试滤池产生的污泥性质,包括污泥产率的变化、重金属含量、污泥的脱水性能、污泥的稳定化程度以及污泥的最终处置方法。 相似文献
723.
Nonylphenol in the environment: a critical review on occurrence, fate, toxicity and treatment in wastewaters 总被引:16,自引:0,他引:16
Soares A Guieysse B Jefferson B Cartmell E Lester JN 《Environment international》2008,34(7):1033-1049
Nonylphenol is a toxic xenobiotic compound classified as an endocrine disrupter capable of interfering with the hormonal system of numerous organisms. It originates principally from the degradation of nonylphenol ethoxylates which are widely used as industrial surfactants. Nonylphenol ethoxylates reach sewage treatment works in substantial quantities where they biodegrade into several by-products including nonylphenol. Due to its physical-chemical characteristics, such as low solubility and high hydrophobicity, nonylphenol accumulates in environmental compartments that are characterised by high organic content, typically sewage sludge and river sediments, where it persists. The occurrence of nonylphenol in the environment is clearly correlated with anthropogenic activities such as wastewater treatment, landfilling and sewage sludge recycling. Nonylphenol is found often in matrices such as sewage sludge, effluents from sewage treatment works, river water and sediments, soil and groundwater. The impacts of nonylphenol in the environment include feminization of aquatic organisms, decrease in male fertility and the survival of juveniles at concentrations as low as 8.2 mug/l. Due to the harmful effects of the degradation products of nonylphenol ethoxylates in the environment, the use and production of such compounds have been banned in EU countries and strictly monitored in many other countries such as Canada and Japan. Although it has been shown that the concentration of nonylphenol in the environment is decreasing, it is still found at concentrations of 4.1 mug/l in river waters and 1 mg/kg in sediments. Nonylphenol has been referred to in the list of priority substances in the Water Frame Directive and in the 3rd draft Working Document on Sludge of the EU. Consequently there is currently a concern within some industries about the possibility of future regulations that may impose the removal of trace contaminants from contaminated effluents. The significance of upgrading sewage treatment works with advanced treatment technologies for removal of trace contaminants is discussed. 相似文献
724.
《International Journal of Sustainable Engineering》2013,6(3):228-234
Disposal of sewage sludge from waste water treatment plants is a serious environmental problem of increasing magnitude. Waste water treatment generates as much as 70 g of dry solids per capita per day. Although one of the disposal solutions for this waste is through incineration, still almost 30% of sludge solids remain as ash. This paper presents results related to reuse of sewage sludge ash in concrete. The sludge was characterised for chemical composition (X-ray flourescence analysis), crystalline phases (X-ray diffraction analysis) and pozzolanic activity. The effects of incineration on crystal phases of the dry sludge were investigated. Two water/cement (W/C) ratios (0.55 and 0.45) and three sludge ash percentages (5%, 10% and 20%) per cement mass were used as filler. The mechanical performance of sewage sludge ash concrete (SSAC) at different curing ages (3, 7, 28 and 90 days) was assessed by means of mechanical tests and capillary water absorption. Results show that sewage sludge ash leads to a reduction in density and mechanical strength and to an increase in capillary water absorption. Results also show that SSAC with 20% of sewage sludge ash and W/C = 0.45 has a 28 day compressive strength of almost 30 MPa. SSAC with a sludge ash contents of 5% and 10% has the same capillary water absorption coefficient as the control concrete; as for the concrete mixtures with 20% sludge ash content, the capillary water absorption is higher but in line with C20/25 strength class concretes performance. 相似文献
725.
针对工业废水采用普通活性污泥法处理易出现的丝状菌型污泥膨胀,分析和总结出五种主要膨胀类型:低负荷型、低溶解氧型、营养缺乏型、高硫化物型、pH值不平衡型。对污泥负荷、溶解氧、污水种类、营养成分及pH值和温度的变化等因素对污泥膨胀中菌胶团和丝状菌生长的相互影响进行阐述,给出污泥膨胀理论,并对不同类型的污泥膨胀提出相应的控制方法。 相似文献
726.
为进一步提高循环式活性污泥工艺(CASS)的脱氮除磷效果,改变其运行方式,采用好氧脉冲曝气,提出频繁硝化-反硝化循环式活性污泥工艺(FND-CASS).结果表明,FND-CASS工艺与CASS工艺相比,在去除污水中有机物方面能力略有下降,但在脱氮除磷方面具有明显的优势.在同样的进水流量且DO浓度控制较低的运行条件下,F... 相似文献
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728.
729.
为探究剩余污泥碱性发酵产物作为碳源对硝化过程及性能的影响,建立了以污泥碱性发酵混合物作为碳源的生物脱氮(BNR)系统.投加初期,氨氧化菌(AOB)和亚硝态氮氧化菌(NOB)活性均受到抑制;16 d后AOB活性开始迅速恢复,NOB活性仍受到抑制,比硝态氮积累速率(SNaPR,以N/VSS计)由初始的0.179 1 g·(g·d)~(-1)下降至0.007 8 g·(g·d)~(-1),系统内亚硝积累率由8.12%上升至91.42%并维持稳定.将污泥发酵混合物分离为污泥发酵液和污泥发酵底泥,考察添加3种不同类型的发酵产物对硝化效果良好的全程硝化污泥硝化活性的影响.结果表明,投加污泥碱性发酵混合物和投加碱性发酵液的实验组,NOB活性皆有所下降,SNaPR由初始的0.179 3 g·(g·d)~(-1)分别下降至0.151 0 g·(g·d)~(-1)和0.161 7 g·(g·d)~(-1);投加发酵底泥的实验组,NOB的活性有所上升,SNaPR由0.179 3 g·(g·d)~(-1)上升至0.186 4 g·(g·d)~(-1).因此,当利用污泥发酵混合物和发酵液作为碳源时,在硝化过程中,能抑制系统内NOB的活性,实现短程硝化过程,有利于加速硝化速率及节省该类型碳源的投加. 相似文献
730.
夏季高温下污水处理厂生物处理系统的硝化性能及强化方法 总被引:1,自引:1,他引:0
本文模拟夏季高温,考察了温度(30~45℃)和氨氮容积负荷对污水处理厂好氧池活性污泥硝化功能及微生物群落的影响,同时探讨中温富集硝化污泥高温驯化前后用于强化受高温冲击的生物处理系统的硝化效果.结果表明,在30~40℃水温下好氧池活性污泥的氨氮去除效果保持在90%以上,硝化菌含量也逐步升高至4. 55%;当水温升至45℃时氨氮去除率和硝化菌含量均分别降至40%和1. 97%.为快速恢复受夏季高温冲击的生物系统,将中温富集硝化污泥在40℃下驯化61 d后,获得硝化活性为(60±5) mg·(L·h)-1的硝化污泥,考察中温富集硝化污泥驯化前后对受高温冲击的生物处理系统的强化效果,发现驯化后的中温富集硝化污泥只需投加5%(体积分数)即可提高10%的氨氮去除率,而未驯化的则需要投加10%(体积分数).上述结果表明,中温富集硝化污泥经驯化后能更好地用于强化受高温冲击的生物处理系统的硝化功能. 相似文献