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COD快速测定方法的应用 总被引:1,自引:0,他引:1
作者介绍的COD快速测定法是利用强酸性消解液在加热和催化剂存在的条件下,水中还原性的物质被K2Cr2O7氧化,K2Cr2O7本身被还原生成Cr3 ,而Cr3 浓度与水样中的COD浓度成正比,通过比色测定Cr3 或Cr6 的吸光度值,从而间接快速测定水中COD的方法.该方法省时、节能,试剂用量小,能同时测定大批量水样. 相似文献
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主要研究以聚丙烯酰胺作为助凝剂的混凝沉淀处理过程,去除蚀刻液废水中的有机物.实验得出两种混凝剂配合助凝剂的最佳投加范围,分别为:聚合氯化铝为200mg/L左右、聚丙烯酰胺为5mg/L左右、聚合硫酸铁为100mg/L左右、聚丙烯酰胺为10mg/L左右.以聚合氯化铝和聚丙烯酰胺组合的处理效果最为理想,CODcr去除率可达86.26%,处理出水CODcr降至419.7 mg/L,达到国家三级排放标准.在实验中,由于蚀刻液废水中含有高浓度氯离子,严重干扰了CODcr.的正常测定.针对这一不足,采用了银盐沉淀法来屏蔽氯离子,相对误差可以控制在-2.5%~ 1.4%之间.该法能够稳定、准确地测定高浓度氯离子废水的CODcr.提供了蚀刻液CODcr测定的有效方法. 相似文献
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该文通过打小样试验,挑选适用于碱性染色工艺和弱酸性染色工艺的两种不同染料各九支,并结合实际生产中大部分染厂所用工艺,应用三种不同工艺对涤纶织物进行上染,收集染色残液测量pH和COD.使用碱性染色工艺,染液在织物上染前后pH值有变化,残液pH值达到GB4287—92中的相关规定;使用弱酸性染色工艺和染厂所用工艺,染液在织物上染前后pH基本没有变化.对比三种工艺收集残液的COD值,发现使用碱性染色工艺的分散染料,收集的残液COD明显偏低。这为大生产中印染厂优化染色工艺、节能减排、降低综合成本提供了试验依据。 相似文献
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化学需氧量(COD)是水质分析与监测的主要指标之一,能够有效地反映水体有机污染的程度.文章介绍了海南省当前海水COD的主要测定方法,并用滴定法和比色法对海水水样进行比对分析.同时介绍了海水COD测定的当前研究进展. 相似文献
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Color and COD retention by nanofiltration membranes 总被引:3,自引:0,他引:3
In the present study the application of the nanofiltration process was investigated mainly in the retention ofcolor and chemical oxygen demand (COD) present in textile industry wastewater. Nanofiltration experiments were carried out in a pilot unit, operating in crossflow. Three different types of spiral wound membranes, DK 1073, NF 45 and MPS 31 were used simultaneously in the same unit. The results of the tests showed that for color retention, the values were around 99% for the DK 1073 and NF 45 membranes and the 87% for COD retention for the DK 1073. The permeate flux for the different wastewaters varied from 30.5 to 70 L/h.m2. Fouling was observed in all membranes due to the accumulation of molecular species close to the filtering surface. The process was efficient and promising for the reuse of wastewater from this type of industry. 相似文献
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COD测定方法的研究动态 总被引:3,自引:0,他引:3
从采用不同的氧化剂测定、寻找新的催化剂、样品消解方法的改进、在线监测仪器及与其他综合指标的相关关系等几个方面论述了化学需氧量测定方法的发展与研究现状. 相似文献
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把IIC总线应用于污水化学需氧量监测系统中现场控制器、中央控制器和数据存储器之间的数据传输.根据IIC的数据传输协议焊接硬件电路,在keil上编写单片机程序,在虚拟机上编写Linux的驱动程序和测试程序,并把最后生成的可执行文件下载到硬件学习板上进行运行. 相似文献
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Membranes can be used for wastewater treatment. The selection of the appropriate membrane depends on a number of factors, such as waste characteristics, nature of materials present in the wastewater, concentration, temperature, pH, etc. If the wastewater contains low molecular weight organics, reverse osmosis (RO) is the best treatment process. RO membranes allow solvent (water) to pass and prevent the transport of organics, either completely or partially. In this study, raw wastewater from an alcohol manufacturing plant was treated using a RO process. The chemical oxygen demand (COD) of the wastewater was between 35000-40000 mg/l due to the presence of organic components. Eight polymeric membranes (e.g. FT30, PVD, DSII, DS, BW30, 37100, 3750 and NF45) were used in total. None of the membranes were able to reduce COD to a desirable level (i.e. less than 200 mg/l) in one step. However a two-step process could be designed for wastewater treatment. Based on data obtained for flux and rejection, the NF45 nanofiltration membrane exhibited the best performance. A high volume of fluid can pass through the NF45 membrane because of its high porosity. The flux of this membrane (i.e. 15 kg/m2.h) was higher than the reverse osmosis membranes tested. The NF45 membrane decreased COD to a greater extent than the other membranes tested (52%). While the PVD membrane showed better efficiency compared to the other reverse osmosis membranes, probably because of its material of construction and configuration. 相似文献
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通过高锰酸钾法对南京部分地区的非饮用水的化学耗氧量(COD)进行了测定.实验结果表明,秦淮河下游的COD为6.879,秦淮河中游的COD为6.282,秦淮河上游的COD为6.395,玄武湖湖水的COD为4 390,长江的COD为2.259. 相似文献
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探讨了利用微波消解测定水中化学需氧量(COD)的各种条件实验。改进了测定COD的方法,并测定了多种水样。其相对标准偏差为1%~5%。测定结果表明:微波消解具有明显的优点。 相似文献
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根据化学需氧量(COD)这一条件性指标国家规定的测定的条件出发,在实验中改变原工艺中单一条件进行测量,通过测试数据的变化找出各因素对测量化学需氧量(COD)精度的影响。 相似文献