施用污泥堆肥对龙葵生长及富集重金属的影响
2020-05-21朱秀红温道远韩晓雪杨金橘茹广欣
朱秀红 温道远 韩晓雪 杨金橘 茹广欣



摘要:研究了施用不同比例(0、5%、10%、15%、20%)的城市污泥堆肥对龙葵生长和重金属含量的影响以及混合土壤理化性质、重金属含量的变化,以探究城市污泥堆肥农用潜力。结果表明,城市污泥堆肥不同施用比例下,土壤氮磷钾和有机质含量均显著增加,施用污泥堆肥不同比例的龙葵植株干重从大到小顺序为5%、10%、15%、 0(CK)、20%,当施用比例为5% 时,龙葵的干重达最大值5.04 g,较对照不施城市污泥堆肥提高了49.81%。土壤中的重金属 Cu、Zn、Pb、Cr、Cd 等含量均随污泥施用比例的增加逐渐升高,但均不超过污泥农用泥质B级标准。混合土壤中的重金属被龙葵富集,富集量随堆肥的用量逐渐升高。低浓度下(施用比例为5%)龙葵生长良好,对混合土壤有很強的耐受性,高浓度(施用比例为15%~20%)会对龙葵植株产生毒害作用,甚至导致植株凋亡。综上分析,低浓度(5%)为最适宜龙葵生长的污泥堆肥施用浓度。
关键词:城市污泥堆肥;龙葵;植物生长变化;重金属
Abstract:The effects of different proportions (0%,5%,10%,15% and 20%) of municipal sludge compost on plant growth and heavy metal content and the changes of physical and chemical properties and heavy metal content of mixed soil were studied to explore the agricultural potential of municipal sludge compost. The results showed that the soil nitrogen, phosphorus, potassium and organic matter content increased significantly under different sludge composting ratios. The order of dry weight of Solanum nigrum L. plants under each treatment was 5% > 10% > 15% > 0(CK) > 20%, when the sludge composting ratio is 5%, the dry weight of Solanum nigrum L. reaches a maximum of 5.04 g, which is 49.81% higher than that of without municipal sludge composting(CK). The contents of heavy metals such as Cu, Zn, Pb, Cr and Cd in the soil increased gradually with the increase of the proportion of sludge application, but they did not exceed the B grade standard for Sludge Agricultural Mud. The heavy metals in the mixed soil were enriched by Solanum nigrum L., and the enrichment amount gradually increased with the amount of compost. The experiment showed that Solanum nigrum L. grew well at low concentration and was highly tolerant to mixed soil, high concentration(15%~20%) may cause toxic effects on Solanum nigrum plants and even cause plant apoptosis. In summary, the low concentration(5%) is the most suitable concentration of fertilizer for the growth of Solanum nigrum L.
城市污泥中含有丰富的有机质、N、P及植物生长所必需的微量元素,是一种很好的有机肥源[1 ]。大量研究表明,城市污泥通过混合添加剂进行堆肥,可稀释重金属浓度,提高污泥堆肥养分含量,改善土壤结构和性能,从而进行农业利用[2 ]。城市污泥中含有大量重金属,高温堆肥虽能有效降低其重金属的生物有效性,降低其毒性,但其含量并不会消减,因此堆肥污泥资源化利用不可避免的会将有毒有害的重金属带入到土壤中[3 ]。国内外学……
