全自动间断化学分析法快速测定污水中的无机氮

为探究全自动间断化学分析仪-分光光度法对污水测试的适用性,采用全自动间断化学分析仪批量快速检测农村生活污水、城市污水、养猪沼液和垃圾渗滤液中的无机氮浓度,并与相同测试原理的国家标准或行业标准方法(以下简称"标准法")比对,分析其适用性及影响因素。结果表明:该方法对氨氮、亚硝酸盐氮和硝酸盐氮检出限分别为0.011、0.005 mg/L和0.017 mg/L,精密度RSD均小于5%;4种污水样本检测结果与标准法数据显著相关,相关性系数r在0.9999~1.0000,RSD均在20%以内。对农村生活污水、养猪沼液和垃圾渗滤液适用性较好,准确度高,相对误差均≤±10%,但对浓度较低、成分复杂的城市污水,准确度略低,相对误差>±20%。该方法样品和试剂用量比标准法分别节省60%、76%~98.5%,废液产生量降低92%,测试时间效率提升3倍,但需注意试剂类型、稀释倍数和反应器皿等因素对测试结果的影响。

Rapid Determination of Inorganic Nitrogen in Wastewater with Full-Automatic Batch Chemical Analysis

Full-automatic batch chemical analyzer-spectrophotometric method(FBCS) was used for the rapid determination of inorganic nitrogen in rural domestic wastewater, municipal wastewater, digested piggery wastewater, and landfill leachate. The applicability and influencing factors of FBCS were investigated by comparing the results with those of standard method. The results indicated that detection limits of ammonium nitrogen(NH+4-N), nitrite nitrogen(NO-2-N) and nitrate nitrogen(NO-3-N) were 0.011, 0.005 mg/L and 0.017 mg/L, respectively, and detection precision RSD(n=6) were less than 5%. The results of FBCS and standard method were significantly correlated with correlation coefficients of 0.999 9~1.000 0 and RSD of < 20%. FBCS showed good applicability, high accuracy, and low relative error(below ±10%) for detecting rural domestic wastewater, digested piggery wastewater, and landfill leachate, while showed slightly lower(relative errors of > ±20%) accuracy for the measurement of municipal sewage samples with low concentration and complex composition. Compared with standard method, FBCS requires less sample(60%) and reagent(76%~98.5%), produces 92% less liquid waste, and reduces testing duration by 3 times. The potential impact of reagent type, dilution factor, and reaction vessel on the results need to be taken into consideration.