水和废水中五日生化需氧量测定全程质量控制

质量控制是环境监测赖以生存和发展的基础,加强全程质量控制才能确保监测数据的准确性和可靠性。结合环境监测工作实际,应用最新修订国标方法-稀释与接种法(HJ505-2009)对水和废水中五日生化需氧量测定进行了全程质量控制技术探讨。概述了方法原理,简介了方法所需仪器与试剂,深入探讨了运用该方法进行水和废水中五日生化需氧量测定全程质量控制技术问题。指出在最新修订国标方法基础上,正确进行水样干扰消除和预处理操作,准确确定水样稀释倍数,严格控制测定和培养温度,优先选取电化学探头法测定溶解氧浓度,准确进行测定结果数据处理,切实规范监测数据结果填报,能够在确保水样五日生化需氧量测定精密度和准确度的同时简化大批量成分复杂水样测定过程。

Whole-Course Quality Control in Determining Water and Wastewater Biochemical Oxygen Demand after Five Days

Quality control is the basis for survival and development of environmental monitoring.Only strengthened whole-course quality control can ensure the accuracy and reliability of monitoring data.Combined with working practice of environmental monitoring,the whole-course quality control was conducted to determine the biochemical oxygen demand after five days（BOD5） in water and wastewater by applying the latest revised national standard method—dilution and inoculation method（HJ505-2009）.The principles of this method are summarized while the requested instruments and reagents of the method are briefly introduced.The whole-course quality control technology questions in the determination of BOD5 in water and wastewater by using this method have been analyzed in depth.It is pointed out that on the base of the latest revised national standard method,the accuracy and precision in determining BOD5 in water samples can be guaranteed by eliminating the interference to the water samples and preprocessing the pretreatment accurately,confirming the dilution factor of water samples,measuring and controlling the cultivation temperature strictly,choosing electrochemical probe method preferably to determine the dissolved oxygen concentration,processing the data of determination results accurately and standardizing the monitoring data report effectively.It also can simplify the determining procedure of large batches of compositional complicated water samples.