凹凸棒石-污泥共热解生物炭对玉米苗期生长特性和重金属富集效应的影响

Influence of biochar prepared by co-pyrolysis with attapulgite and sludge on maize growth and heavy metal accumulation

利用凹凸棒石和污泥制备7种不同比例(0、5%、10%、15%、20%、25%、30%)的凹凸棒石-污泥共热解生物炭。通过盆栽试验调查凹凸棒石-污泥共热解生物炭对玉米生长和土壤中重金属(Cu、Zn、Pb、Ni、Cd)富集的影响。结果表明:凹凸棒石添加量为15%的凹凸棒石-污泥共热解生物炭显著促进了玉米的出苗率和株高,分别增加了55.87%和24.35%,凹凸棒石添加量为20%时,根长、鲜质量和干质量分别增加了65.57%、79.85%和76.84%。凹凸棒石-污泥共热解生物炭对重金属的富集有显著抑制作用,凹凸棒石添加量为15%时,显著抑制了玉米对Cu、Zn、Ni、Cd的富集,分别减少了55.01%、49.27%、54.87%、41.99%,凹凸棒石添加量为20%时,使重金属Pb的富集量减少了34.01%。凹凸棒石的添加增强了污泥生物炭的钝化功能,为污泥安全利用提供了一种新方法。

Seven kinds of biochar were prepared by co-pyrolysis with sludge and different amounts of attapulgite(0, 5%, 10%, 15%, 20%,25%, 30%)and were applied to maize seedlings in pot experiments in order to stabilize heavy metals(Cu, Zn, Pb, Ni, Cd)and affect growth. The results suggested that adding 15% attapulgite to biochar significantly increased maize germination rate and plant height, which increased by 55.87% and 24.35%, respectively. When the amount of attapulgite added was 20%, root length, fresh weight, and dry weight increased by 65.57%, 79.85%, and 76.84%, respectively. Biochar prepared by co-pyrolysis with attapulgite and sludge significantly inhibited the enrichment of heavy metals. The addition of 15% attapulgite significantly inhibited the accumulation of Cu, Zn, Ni, and Cd in maize, reducing accumulation by 55.01%, 49.27%, 54.87%, 41.99%, respectively. Furthermore, the addition of 20% attapulgite reduced the accumulation of Pb by 34.01%. The addition of attapulgite enhances the passivation function of sludge biochar and provides a new method for the safe use of sludge.