Phytoremediation of Cd and Pb in polluted soil: a systematic review

As a result of urbanisation and increased anthropogenic activity, heavy metal pollution in soil, water, and the mesosphere indicates the growth of environmental problems affecting food quality and human health in cities. The present study aimed to systematically review Cadmium (Cd) and Lead (Pb) concentrations in polluted soil that used phytoremediation for cleaning. International databases were searched from January 2005 to February 2020. Data obtained from 11 articles showed that minimum and maximum concentrations of Cd (0.032 ± 0.027 and 22.84 ± 2.59 mg/kg respectively) and Pb (0.05 ± 0.15 and 15.40 ± 10.05 mg/kg), respectively. The concentration of heavy metals was more in Guangzhou, China. The minimum and maximum concentrations of heavy metals were for Cd in Bingham, England, and Guangzhou, China respectively. Soil pH affects the ability to extract cadmium in the soil and by increasing soil pH, increases the uptake of cadmium or decreases the dissolution of cadmium-containing minerals. The use of residues including a variety of biochar to help contaminated soils can be an effective and sustainable way to purify lead-contaminated soils and increase food safety and health.