水闸运行对丹河不同形态河段典型污染物降解系数的影响

Effect of Sluice Operation on Degradation Coefficient of Typical Pollutants in Different Form Reaches of Danhe River

水闸对河流的阻隔作用改变了河流流速、流量,引起河流形态变化,使得污染物输运也随之发生改变,直接影响河流的水环境容量。以小水闸控制下的丹河为例,通过水闸运行控制河流水量,探究河流流速对污染物降解系数的影响。结果表明,除TN外,COD、BOD5、TP的降解系数与河段流速有非常显著的线性回归关系(p<0.01),不同污染物的降解系数随河流流速的增大而增大,且顺直河段的污染物降解系数高于弯曲河段污染物降解系数;开闸放水后顺直河段COD、BOD5、TN、TP降解系数增加,弯曲河段COD、BOD5、TP降解系数减小,仅TN降解系数增加;开闸放水后顺直河段流速增加0.14 m/s,COD、BOD5、TN、TP降解系数分别增加0.94、0.30、0.72、1.93 d^(-1);弯曲河段流速增加0.01 m/s,COD、BOD5、TP的降解系数分别降低0.44、0.28、0.38 d^(-1),TN降解系数增加0.87 d^(-1)。

The barrier effect of sluice on the river changes the velocity and discharge of the river,causes the change of the river shape,changes the transport of pollutants,and directly affects the water environment capacity of the river.In this study,the Danhe River under the control of small sluice is taken as the research object.The river water quantity is controlled by sluice operation,and the influence of river velocity on pollutant degradation coefficient is explored.The results show that the degradation coefficients of COD,BOD5 and TP in the experimental reach except TN have significant linear regression relationship with the flow velocity of the reach(p<0.01).The degradation coefficients of different pollutants increase with the increase of the flow velocity,and the degradation coefficients of pollutants in the straight river section are significantly higher than those in the curved river section.After opening the sluice,the degradation coefficients of COD,BOD5,TN and TP increase in the straight river section,while the degradation coefficients of COD,BOD5 and TP decrease in the curved river section,and only the TN degradation coefficient increases.After opening the sluice,the flow velocity of straight river section increased by 0.14 m/s,and the degradation coefficients of COD,BOD5,TN and TP increased by 0.94,0.30,0.72 and 1.93 d^(-1),respectively.The flow velocity of curved river section increased by 0.01 m/s,the degradation coefficients of COD,BOD5 and TP decreased by 0.44,0.28 and 0.38 d^(-1),and the degradation coefficients of TN increased by 0.87 d^(-1).