Chen Xiaoling, Feng Jianru, Mou Huaqian, Liang Zheng, Ding Tianzheng, Chen Shiyu, Li Feili
College of Environment, Zhejiang University of Technology, Hangzhou 310032, China.
Jinhua Water Treatment Co., Ltd., Jinhua 321016, China.
Toxics. 2022 Dec 31;11(1):43. doi: 10.3390/toxics11010043.
The development of phytoremediation by garden plants is an effective way to deal with the dilemma of municipal sewage sludge disposal. In this study, two ornamental plants were used as phytoremediation plants to rehabilitate heavy-metal-contaminated municipal sewage sludge in field experiments, and the role of exogenous phytohormone IAA was also tested. Ornamental plants Loropetalum chinense var. rubrum (L. rubrum) and Rhododendron pulchrum (R. pulchrum) adapted well to the artificial soil made of municipal sewage sludge, and the concentrations of Cu, Zn, Pb, and Ni were decreased by 7.29, 261, 20.2, and 11.9 mg kg−1, respectively, in the soil planted with L. rubrum, and 7.60, 308, 50.1, and 17.7 mg kg−1, respectively, in the soil planted with R. pulchrum, accounted for 11−37% of the total amounts and reached significant levels (p < 0.05), except Cd. The concentration of Pb in all parts of the two ornamental plants was increased, as well as most heavy metals in L. rubrum root. As a result, three months after transplant, the phyto-extraction amounts in L. rubrum were 397, 10.9, and 1330 μg for Ni, Cd, and Pb, respectively, increased by 233% to 279%. The phyto-extraction amount in R. pulchrum were 1510, 250, and 237 μg for Zn, Pb, and Cu, respectively, increased by 143% to 193%. These results indicated a potential to remediate heavy metals of the two ornamental plants, especially L. rubrum. The results of correlation analysis implied that the interaction of heavy metals in the plant itself played an important role in the uptake of heavy metals. This seemed to explain why applying IAA in the experiment had little effect on plant growth and phytoremediation of heavy metals. This study provided a green and feasible idea for the proper disposal of municipal sewage sludge.
利用园林植物进行植物修复是解决城市污水污泥处置困境的有效途径。本研究选用两种观赏植物作为植物修复植物，通过田间试验修复重金属污染的城市污水污泥，并测试了外源植物激素吲哚乙酸（IAA）的作用。观赏植物红花檵木（L. rubrum）和锦绣杜鹃（R. pulchrum）对由城市污水污泥制成的人工土壤适应性良好。种植红花檵木的土壤中，铜、锌、铅和镍的浓度分别降低了7.29、261、20.2和11.9 mg kg−1，种植锦绣杜鹃的土壤中，铜、锌、铅和镍的浓度分别降低了7.60、308、50.1和17.7 mg kg−1，除镉外，占总量的11% - 37%，达到显著水平（p < 0.05）。两种观赏植物各部位的铅含量均增加了，红花檵木根部的大多数重金属含量也增加了。因此，移栽三个月后，红花檵木对镍、镉和铅的植物提取量分别为397、10.9和1330 μg，增加了233%至279%。锦绣杜鹃对锌、铅和铜的植物提取量分别为1510、250和237 μg，增加了143%至193%。这些结果表明这两种观赏植物具有修复重金属的潜力，尤其是红花檵木。相关分析结果表明，植物体内重金属之间的相互作用在重金属吸收中起着重要作用。这似乎解释了为什么在实验中施用IAA对植物生长和重金属植物修复几乎没有影响。本研究为城市污水污泥的合理处置提供了一个绿色可行的思路。
