Combined Remediation Effects of Pioneer Plants and Solid Waste towards Cd- and As-Contaminated Farmland Soil

Abstract

The development of phytoremediation technology is constrained by gentle phytoextraction efficiency and slow biomass accumulation. In this study, a combined remediation of pioneer plants and solid waste towards Cd- and As-contaminated farmland soil was explored. Pioneer plants Cynodon dactylon and two material formulas (Steel slag (SS):pyrolusite (PY):ferrous sulfide (FS) = 3:3:2 or 1:2:8) were used in pot experiments. The DTPA method was used to extract the bioavailable heavy metals from soil, and then, the reduction rates of the bioavailable heavy metals were calculated. After harvesting plants, data of moisture content, biomass, root length and plant height were obtained. The remediation effect was evaluated according to the above indexes. The experimental results showed that the remediation effect of Bidentis pilosa was better than that of Cynodon dactylon. The addition of solid waste material significantly reduced the content of bioavailable Cd and As in soil by 97.73% and 53.54%, respectively. Suitable wastes may be a potential addition to heavy metal contaminated soils to promote phytoremediation of heavy metals.