环渤海河流COD入海通量及其对渤海海域COD总量的贡献

于2013年8月~2014年10月,分季节对环渤海36条入海河流进行了4次调查采样,核算其COD入海通量,并评估其对渤海水质的影响.结果表明,大部分河流都受到了严重污染(COD为地表IV类),但污染最重的河流并不是COD入海通量最大的河流,COD的最大值和COD入海通量的最大值不具有一致性;环渤海河流排入渤海的COD_Cr的年入海通量最大(606万t),其次是酸性COD_Mn的入海通量(62万t),碱性COD_Mn最小,为53万t;环渤海河流在丰水期COD的入海通量约占全年的68%,其次是平水期(28%),枯水期最小(4%);整个渤海海域的碱性COD_Mn总量为239万t,其中环渤海河流输入约占25%.

Influxes of COD in coastal rivers around the Bohai Sea and their contribution for total COD capacity in the Bohai Sea

During August 2013 to October 2014, four seasonal field sampling and investigation were conducted to get the fluxes of COD in 36coastal rivers around the Bohai Sea, the effects of COD on seawater quality were evaluated as well. The results showed that most rivers have been heavily polluted (COD reached grade IV, National Surface Water Quality Standard). However, the maximum values of COD and flux of COD did not appear in the same river. There was no significant correlation was observed between maximum value of COD and the maximum flux of COD. The annual flux of COD_Cr was the highest (606million tons), followed by the acidic COD_Mn (62million tons), the flux of alkaline COD_Mn was the lowest one with 53million tons. In rainy season, the flux of COD shared 68% of total value, followed by normal water season (28%) and the withered water period (only 4%). Approximately 25% of total COD_Mn (239million tons) in the Bohai Sea was from coastal rivers.