人工湿地净化海水养殖外排水影响因素与效果实验研究

以海水养殖外排水为处理对象,构建芦苇复合垂直流人工湿地模拟系统进行处理效果的影响因素(盐度,水力负荷,污染负荷)实验。植物选择芦苇,种植密度为48株/m2,基质填料选择细纱、蛭石、高炉矿渣、沸石和砾石。实验结果显示,随着盐度的升高,人工湿地对CODMn和NH4-N的去除率差异不显著(P>0.05),对PO4-P的去除率在逐渐降低,变化显著(P<0.05),但芦苇表现出较强的耐盐性,在盐度20时生长良好。随着水力负荷的增加,人工湿地对CODMn、NH4-N和PO4-P的去除率呈现出降低的趋势,变化显著(P<0.05);而当污染负荷增加时,去除率呈现出先增加后降低的趋势。综合考虑运行合理性及运行效果,得出合理工况为盐度20,水力负荷0.4 m3/(m2.d),污染负荷CODMn 10 mg/L,NH4-N 2 mg/L,PO4-P 0.5 mg/L。在此工况下,系统稳定运行2个月,显示人工湿地对海水养殖外排水中的污染物具有较好的去除效果。

Experimental research on influence factors and effect of mari-culture effluent purified by artificial wetland

The mari-culture effluent were purified by the reed integrated vertical flow constructed in the wetland simulation system,and several impact factors,such as salinity,hydraulic load and pollution load were analyzed.Selecting reed as the plant of constructed wetland,the density of reed was 48 per square meter,and the matrix included fine sand,vermiculite,blast furnace slag,zeolite and gravel.The results showed that with the increase of salinity,the removal rate of CODMn and NH4-N didn’t change significantly(P>0.05),the removal rate of PO4-P was decreased gradually and changed significantly(P<0.05),but the reed showed a strong salt-tolerant ability,growing well under the condition when the salinity reached to 20.As the hydraulic load increasing,the removal rate of CODMn,NH4-N and PO4-P also showed a fall tendency and changed greatly(P<0.05).While the pollution load increasing,the removal rate of CODMn,NH4-N and PO4-P showed a trend that increased first and then decreased gradually.Considering the reasonableness and operation effect,it could be concluded that a reasonable operating condition with the salinity of 20,the hydraulic loading of 0.4 m3/(m2·d),and the pollution load of CODMn,NH4-N,PO4-P was 10 mg/L,2 mg/L,0.5 mg/L,respectively.The system operated at this condition for two months,and it showed a good removal performance of mari-culture effluent with such constructed wetland.