底泥添加生物炭对苦草生长及水质的影响

Effects of adding biochar to sediment on growth of Vallisneria natans and water quality

生物炭和沉水植物均能吸附或吸收污染物质从而净化水质,然而生物炭对沉水植物生长的影响以及二者共同作用对水质的影响仍不是很清楚。通过室内试验探究在苦草(Vallisneria natans)生长的底泥中添加不同量(CK:0 mg/g,T1:33 mg/g,T2:66 mg/g,T3:132 mg/g)的稻壳生物炭对水质及苦草生长的影响。实验结果表明:(1)在底泥中添加少量生物炭会促进苦草对水体中总氮和总磷的去除,底泥中添加生物炭过量不利于水体总氮和总磷的去除(2)底泥中添加适量的生物炭会促进水体中Chl-a的去除,增加水体中DO的含量。生物炭会增加水体中TOC的浓度,增加水体中的电导率,并且增加程度随着生物炭的添加量的增加而升高。(3)底泥中添加适量生物炭会促进苦草的生长,使苦草的生物量增加,添加生物炭的量过高会抑制苦草地下部分的生长从而使苦草的生长受到抑制。

Both biochar and submerged macrophytes can absorb the pollutants in water. However,the effects of biochar on the growth of submerged macrophytes and the influence of the two parties on the water quality are still unclear. In this study,a control experiment was carried out to investigate the effects of adding four amounts biochar( CK: 0 mg/g,T1: 33 mg/g,T2:66 mg/g,T3: 132 mg/g) to sediment on water quality and growth of Vallisneria natans. The results show that( 1) adding rice husk biochar could promote the removal of total nitrogen and phosphors in water. Among the three treatments T1 is the best group,with the removal rate reaching 80. 5% and 93. 5%;( 2) Appropriate amount of biochar added to sediment could promote the removal rate of Chl-a,and increase DO in water. The TOC and COND in the water increased with the increasing biochar addition in the sediment;( 3) Adding appropriate amount of biochar could promote the growth of Vallisneria natans,with an increase of their biomass. However,adding excessive biochar could inhibit the growth of the belowground part of Vallisneria natans.