测压法测定BOD的研究与应用

对采用差压式直读测定装置测定生化需氧量(BOD)的方法进行了研究,该方法操作简单、直观性好,简化了大量烦琐操作并可连续测定BOD。通过测压法与稀释接种法(测定BOD的国家标准方法)的对比及差异性统计检验,表明这两种方法没有显著性差异。经对实际水样的分析并与标准稀释法的分析结果进行比较,该方法准确度较高。     

环流曝气塔中生物脱氮过程的研究

利用环流曝气塔进行同时硝化/反硝化(sND)脱氮实验.实验中,分别采用不同降解性能的碳源以及采用不同的碳源投加方式,研究反应器内的脱氮过程,监测处理过程中NO_x^--N浓度和溶解氧DO的变化.实验显示,在COD 800mg/L+800mg/L的分批加料方式下,NH₄⁺-N的降解得到加强,出水中NH₄⁺-N浓度低于3mg/L;利用较难降解物质作为碳源时,利于反应器内低溶解氧条件的出现,促进了反硝化的进行,实验在采用醇类碳源时脱氮效果好于葡萄糖的情况.     

微量曝气条件下SBR反应器的运行特性研究

在 4种不同供气量条件下 ,研究了SBR反应器去除COD和氧化氨氮的沿程变化规律 ,重点考察了在微量供气、低溶解氧条件下的反应器运行特性 .在本试验运行条件下 ,4 0L h的供气量刚好提供了去除COD和氨氮所需的氧 ,此状态下反应器内的溶解氧平均水平为 0 5mg L .试验中对运行工艺参数DO、ORP和pH的监测表明 ,这些参数在一个运行周期内具有一定的变化规律 ,并且它们的变化与反应器内的物质状态存在严格的对应关系 .     

Environmentally Sensitive Productivity Analysis of the Canadian Pulp and Paper Industry, 1959-1994: An Input Distance Function Approach

This study employs a parametric input distance function that incorporates both desirable and undesirable outputs to provide a more complete representation of the production technology from which environmentally sensitive productivity and efficiency measures can be generated. This framework also generates pollution abatement cost estimates that are useful for policy making. An input-based Malmquist index of productivity growth that appropriately credits the producer not only for increases in marketable or desirable outputs but also for the production of improved environmental quality through pollution abatement activities is derived from the input distance function. The method was applied to time series data from the Canadian pulp and paper industry. Our shadow price estimates indicate that the marginal cost to producers of pollution control has been rising. The main conclusion of this study is that productivity improvement, from the social viewpoint, has been stronger than conventional measures would suggest.     

A Mixed-Order Model to Assess Contaminant Declines

We introduce a generalized form of the common first-order (exponential) decay model, that has potential utility for describing contaminant declines in environmental applications, particularly when declines are a mixture of many underlying processes. The exponent on contaminant concentration is left as a free parameter allowing the order of the reaction to be determined by the data. The mixed-order model is more flexible than models with the exponent determined a priori, facilitating an improved fit to observed behavior. We demonstrate the utility of this model, and compare it to two other models, by estimating PCB concentration declines in Lake Michigan fishes.     

Methane Production in River and Lake Sediments in Taiwan

To investigate the relationship between methane production in the sediments and pollution of the river and lake, biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of the water sample, organic matter content and methane production of the sediment were measured. Experimental results indicated that BOD, COD and organic matter contents were low in Bei-tan Lake, the I-lan River and reservoirs; and methane production of these sediments ranged from 0.24 to 1.06 mg L- 1. However, BOD, COD and organic matter contents were high in the Hsin-dan River, Keelung River, drainage river of Taoyuan County, park pond and fishery pond. Methane production of these sediments was between 11.75 and 54.54 mg L-1. Sediments of drain river and fishery pond had high methane production, at 25.41 to 54.54 mg methane L. Methane production of sediments had a good correlation with BOD, COD and organic matter contents. Methane production was proportional to the increment in incubation temperature from 12 to 40C.     

DO和曝停比对单级自养脱氮工艺影响试验研究

为提高SBBR单级自养脱氮系统脱氮性能并考察DO和曝/停比对SBBR单级自养脱氮系统的影响,采用4组对比试验进行研究.结果表明,连续和间歇2种曝气方式均可实现单级自养脱氮,在进水氨氮浓度为160 mg/L左右,温度30℃±2℃,pH值7.8～8.2,HRT为2 d,DO为0.8～1.0 mg/L的条件下,连续曝气系统的氨氮转化率和总氮去除率分别达到80%和70%.DO为(曝气)2.0～2.5　mg·L^-1/(停曝)0.2～0.4 mg·L^-1,曝/停比为2 h∶2 h的系统则达到90%和80%以上.SBBR单级自养脱氮系统的DO应随其曝/停比进行调节,同时还可能与反应器内生物量及微生物在活性污泥和生物膜中的分布情况有关.本研究还探讨了SBBR单级自养脱氮的机理.     

地表水中BOD5监测时的快速估算

阐述了BOD5与溶解氧之间的相关性,提出可以通过溶解氧和水温估算BOD5值,但是,首先要建立水样稀释前溶解氧与BOD5的相关关系.举例说明了对地表水中BOD5值的估算和稀释倍数确定的应用.     

A/O工艺生物除磷和好氧反硝化效果及影响因素研究

采用A/O工艺处理低碳源城市污水,研究了生物除磷和好氧反硝化脱氮效果及其影响因素。试验结果表明:①磷的出水浓度低于0.8mg/L,去除率达到92%~98%;②影响好氧反硝化的主要因素为DO和HRT。当DO控制在2mg/L左右,HRT控制在6h时,好氧反硝化效果最好。增加了脱氮效率,减少了碳源和需氧量。NH4+-N去除率高达94%,总脱氮率可高达76%左右。     

实时控制SBR系统中的短程硝化反硝化

以人工模拟高氨氮废水为研究对象,采用循环间歇式曝气方式,以溶解氧浓度(DO)和pH值为过程控制参数,对SBR系统进行实时控制、全程跟踪.根据此过程中COD、NH4 -N、NO2--N和NO3--N 4项水质指标的变化情况,研究SBR系统中的短程硝化反硝化工艺.实验结果表明,在短程硝化反硝化工艺中,采用较高曝气量,并且在曝气过程中用DO和pH值作为过程控制参数是可行的.