Regard the washing water of rice as a research object, by measuring and comparing the first, second, third washing rice water COD and BOD5, TN, TP, NH4+-N, and other indicators of pollution respectively, we could estimate China's great course of washing rice Pollution of production. The results showed that COD and BOD5 were the main pollutants in the first, second and third washing water, and the TN pollution was moderate, and the pollution load of TP and NH4+-N was relatively small. With the increase of the number of washing, the pollution amount of COD, BOD5, TN, TP and NH4+-N in the scouring water gradually decreased, but the total amount of pollution increased. The COD, BOD5, TN, TP, NH4+-N pollution annual emissions as estimated were 113.52, 64.89, 8.19, 0.36 and 0.24 milliont respectively, with water washing one time; and they increased to some degree with water washing 2-3 times.%以大米淘洗水作为研究对象,分别对第1、2、3次大米淘洗水进行化学需氧量(COD)、五日生化需氧量(BOD5)、总氮(TN)、总磷(TP)、氨氮(NH4+-N)等污染指标进行测定,比较了第1、2、3次大米淘洗水中各污染指标含量,并估算我国大米淘洗过程中的产污量.结果表明:第1、2、3次淘洗水中污染负荷均以COD、BOD5为主,TN污染居中,TP、NH4+-N污染负荷相对较少,随着淘洗次数增加,第2、3次淘洗水中COD、BOD5、TN、TP、NH4+-N污染量逐渐降低,但污染总量增加.经估算,淘洗1次,全国大米淘洗水中COD、BOD5、TN、TP、NH4+-N污染年排放量分别为113.52万、64.89万、8.19万、0.36万和0.24万t;淘洗2~3次,污染年排放量不同程度增加.
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