海洋石油高氯生活污水化学需氧量测定方法改进研究

Research on COD Determination in Domestic Sewage from Offshore Oilfield

海洋石油勘探行业生活污水中含有大量氯离子,正向干扰化学需氧量(COD)监测结果,严重影响测定结果的准确性,给海上平台环保合规运营带来极大隐患。在重铬酸盐法的基础上,通过开展优化及验证实验,开发了一种测定准确、低消耗、低污染的清洁检测方法,为建立适合海洋石油高氯生活污水COD的测定方法提供理论和数据支持。7家检测机构对邻苯二甲酸氢钾标准溶液、环保部环境标准样品及海上生活污水样品的验证实验结果表明,采用低毒的硝酸银作为屏蔽剂,在降低体系酸度的情况下,可以有效屏蔽氯离子并完全氧化有机物,检测结果符合精密度和室间准确度的测试要求。该研究方法适用于海洋石油勘探行业生活污水COD的监测。

Domestic sewage from offshore oil exploration contains a lot of chloride ions. It brings relatively large positive interference to COD monitoring result, making a big potential problem in environmental-compliance operation of offshore oil platforms. In this study, we carried out the optimization experiment of silver precipitation method, established a clean, accurate, low-consumption and low-pollution determination method. The verification experiments of 7 testing institutions show that the use of low-toxic silver nitrate as a shielding agent can effectively shield chloride ions and completely oxidize organic matters, and the test results can meet the test requirements of precision and inter-laboratory accuracy, in the case of reducing the acidity of the system. This research method is applicable to the monitoring of COD in domestic sewage from offshore oil exploration.