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91.
92.
生化需氧量是评价水体受有机物污染的相对耗氧指标。此生物氧化全过程进行的时间长,如在20℃培养时,完成此过程需100多天。BOD5标准测定方法采用稀释接种培养法,缺点是测定周期太长(需5天),不能及时反映水质指标,因此人们一直在研究BOD的快速测定方法。文章从BOD的特点研究BOD2和BOD5的关系,摸索了一种BOD5的快速测定方法;根据菲尔甫斯定律,找出了BOD2与BOD5的相关关系,通过BOD2与BOD5的拟合,建立相关方程,推导出BOD5速测公式,根据BOD2的值能够快速测定BOD5的值,缩短了分析周期,符合环境管理的要求。本方法较严密,省时,可供大家研讨。 相似文献
93.
Since the mid-1970s, Sweden has been depositing 1 million ton d.w sludge/year, produced at waste water treatment plants. Due to recent legislation this practice is no longer a viable method of waste management. It is necessary to improve existing and develop new sludge management techniques and one promising alternative is the dewatering and treatment of sludge in constructed wetlands. The aim of this study was to follow reduction of organic carbon, BOD and nutrients in an industrial sludge containing nitro-aromatic compounds passing through constructed small-scale wetlands, and to investigate any toxic effect such as growth inhibition of the common reed Phragmites australis. The result showed high reduction of all tested parameters in all the outgoing water samples, which shows that constructed wetlands are suitable for carbon and nutrient removal. The results also showed that P. australis is tolerant to xenobiotics and did not appear to be affected by the toxic compounds in the sludge. The sludge residual on the top of the beds contained low levels of organic carbon and is considered non-organic and could therefore be landfilled. Using this type of secondary treatment method, the amount of sludge could be reduced by 50-70%, mainly by dewatering and biodegradation of organic compounds. 相似文献
94.
L. T. Fan Rekha S. Nadkami Larry E. Erickson 《Journal of the American Water Resources Association》1971,7(6):1210-1220
An analytical solution is developed to predict the BOD and DO profiles in a stream having several outfalls of waste and intakes of water. The model also incorporates continuous addition and removal of BOD and DO along the stream. A steady state one dimensional dispersion model is used to describe the transport of BOD and DO in a stream. Changes in stream properties along the length are considered by dividing the stream into several segments and changing the parameters of the BOD and DO equations as needed in each segment. By applying continuity equations at the boundaries of these segments and equilibrium conditions at either ends of the infinitely long stream, the arbitrary constants in the solutions to the differential equations for BOD and DO can be determined. Some applications of the results in studying water pollution problems are illustrated. 相似文献
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Charbel Mahfou Antoine El Samrani Rita Mouaw Walid Hleihel Rim El Khati Bruno S. Lartiges Na¨?m Oua¨?ni 《环境科学学报(英文版)》2009,21(1):120-126
Biofilms grown inside two sewage collecting pipes located in industrial and residential areas are studied. Bacterial biomass inside three layers of biofilms was evaluated. Biofilm cohesion under different mixing rate and ionic strength was also investigated. Effects of physical and chemical parameters in the biofilms were evaluated by monitoring turbidity, chemical and biochemical oxygen demands. Extracted organic matter from biofilms was partitioned to polar, aromatic and saturated fractions using activated silica column chromatography. Results revealed that bacterial biomass growth depending on biofilm thickness and stratification. The most loaded stratum in bacterial biomass was the sewage-biofilm interface stratum that represented 51% of the total bacterial biomass. Stirring rate and ionic strength of mono and bivalent salts showed a major influence in biofilm disruption. The stirring time enhanced the exchange dynamic and matter capture between biofilm fragments at the critical stirring rate 90 r/min. Sodium chloride showed the dispersing effect on biofilms in suspension, and decreased the BOD5 (biochemical oxygen demand) beyond the physiological salt concentration. 相似文献
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糠醛制造业在生产过程中会产生大量高浓度废水,属重污染行业。通过实测其塔下废水中化学需氧量(COD)和生化需氧量(BOD)的产生量,并结合糠醛制造业具体工作实际进行数据分析,作者认为:塔下废水属难生化性废水;COD和BOD产生量与企业设计生产能力无直接关系;设备陈旧、管理粗放是影响COD和BOD产生量的主要因素;而从源头减少污染物的产生,是提高中国糠醛制造业活力和竞争力的关键。 相似文献
99.
基于理论分析,提出CODCH4/COD值作为废水厌氧可生化性的评价指标,确定了CODCH4/COD值表示厌氧可生化性的数值界限。同时,在BMP分析的基础上,采用CODCH4/COD值考察了垃圾渗滤液的厌氧可生化性,并与BOD5/COD值评价结果进行了对比。实验结果显示,CODCH4/COD值与BOD5/COD值用于垃圾渗滤液可生化性的评价,得出的结论具有相似性,但CODCH4/COD值大于BOD5/COD值。究其原因:好氧条件下,总的生化耗氧量(BOD)u小于理论完全需氧量(COD);厌氧条件下,有机物完全去除时CODCH4(理)等于理论完全需氧量。此外,BOD5测试时间仅5 d,而BMP测试时间一般在30 d以上,从而使微生物有足够的时间去适应废水水质,故能较好地反映废水的可生化性。 相似文献
100.
测量不确定度(uncertainty of measurement)是表征合理地赋予被测量之值的分散性,与测量结果相联系的参数。不确定度一词指可疑程度,广义而言,测量不确定度是对测量结果正确性的可疑程度。如何对测量结果的不确定度进行合理评定,一直是困扰检测实验室的一个难题。依据HJ505—2009标准的方法,测定了水样的生化需氧量BOD5,估算了测试过程中的随机效应和系统效应所产生的不确定度分量,最终评定了生化需氧量浓度的测量不确定度。 相似文献