池塘残饵对底泥氮、磷释放影响的模拟研究

Effect of Feed Residues on the Release of Nitrogen and Phosphorus of Pond Sediment

运用室内静态模拟的方法,设置静态释放组(A组)和饲料添加组(B组),研究了池塘残饵分解对底泥氮、磷释放的影响.结果表明,A组DO高于B组(P<0.05),A组pH值为中性,B组pH值呈弱酸性.添加饲料后,B组硝态氮低于A组(P<0.05),而B组活性磷高于A组(P<0.05).实验第2~14 d,A组氨氮高于B组(P<0.05),此后B组氨氮升高,实验结束时B组氨氮高于A组(P<0.05).研究表明,添加饲料的B组,初期氨氮和硝态氮的释放都受到抑制.静态释放的A组,氮的释放变化是先上升,后降低的趋势,而饲料添加的B组,氮的释放变化趋势则是先降低,后升高.B组饲料分解向上覆水释放大量的磷,活性磷的变化呈现先上升后下降的趋势.

The effect of feed residues on release law of nitrogen and phosphorus in water-sediment interface was studied under the simulated condition in laboratory. Two sets of conditions were applied in this study,static condition( A group) and feed add condition( B group). The results show that DO in A group is higher than that in B group( P <0.05). The pH value is neutral in A group,but pH value of B group became weak acidic. After adding the feed,nitrate nitrogen concentration in A group is higher than that in B group( P <0.05),but orthophosphate concentration in A group is lower than that in B group( P <0.05). At the 2-14th day of experiment,ammonia concentration in A group is higher than that in B group( P < 0. 05),but since then the ammonia concentration in B group begins to rise. At the end of the test,ammonia concentration in B group is higher than that in A group( P < 0. 05). At the beginning of the experiment,ammonia and nitrate nitrogen release restrained in B group. Nitrogen increases first,and then decreases in A group,but the changing regulation is completely opposite in B group. Feed decomposition can produce a large amount of phosphorus in B group,at the same time,orthophosphate changing regulation increases first and then decreases.