氨三乙酸联合微生物对高羊茅修复重金属污染土壤的强化作用

为了研究在氨三乙酸(NTA)和微生物作用下,高羊茅对重金属污染土壤修复能力的变化,以天津污灌区土壤为基质种植高羊茅,通过添加不同浓度的NTA及污泥微生物接种处理,研究不同处理对高羊茅生物量和Cd、Cu、Zn含量的影响.结果表明:单独添加微生物菌液以及NTA与菌液联合均能增加高羊茅地上部和根部的生物量,尤其是单独添加微生物菌液,能够显著增加高羊茅的生物量.单独添加NTA处理时,低浓度的NTA能够增加高羊茅的生物量,高浓度的NTA则使高羊茅的生物量下降.高羊茅富集土壤重金属方面,单独添加NTA能够提高高羊茅对重金属的富集能力,单独添加微生物菌液则对其无影响.NTA联合微生物菌液处理中,10 mmol/kg NTA+菌液处理方式下高羊茅地上部的Cd含量最多,15 mmol/kg NTA+菌液处理下高羊茅根部Cd的含量最多;对于Cu,高羊茅在单独添加15 mmol/kg NTA时,地上部和根部的Cu的含量均达到最大;对于金属Zn,高羊茅地上部分达到最大含量的处理是5 mmol/kg NTA+菌液,根部是15 mmol/kg NTA.综合考虑修复效果和经济成本,可采用10 mmol/kg NTA+菌液的方式强化高羊茅对重金属污染土壤的修复.

NTA and sludge microbe-assisted strengthening phytoremediation of heavy metals in sewage-irrigated soil by Festuca arundinacea L.

In order to study the change of ability of Festuca arundinacea L. remediating heavy metal contaminated soil under different concentrations of NTA and microbe, F. arundinacea was planted using sewage-irrigated soil of Tianjin as culture medium. Plant biomass and Cd, Cu and Zn concentrations in F. arundinacea were investigated by adding different concentrations of NTA and sludge microbe inoculation. The results showed that the addition of microbe alone and NTA combined with microbe increased the biomass of F. arundinacea, especially the addition of microbe alone increased the biomass significantly. Low concentrations of NTA increased biomass, but high concentrations of NTA reduced biomass. NTA enhanced heavy metal-enrichment of F. arundinacea, but the addition of microbe alone did not. The highest concentrations of Cd, Cu and Zn in shoot of F. arundinacea of treatment were 10 mmol/kg NTA with microbe, 15 mmol/kg NTA, 5 mmol/kg NTA with microbe separately. The highest concentrations of Cd, Cu and Zn in root of F. arundinacea of treatment were 15 mmol/kg NTA with microbe, 15 mmol/kg NTA, 15 mmol/kg NTA separately. Considering the remediation effect and economic cost, the suitable choice is to adopt 10 mmol/kg NTA and microbe combined with F. arundinacea to remediate heavy metal contaminated sewage-irrigated soil.