Bioremediation of co-contaminated soil with heavy metals and pesticides: Influence factors, mechanisms and evaluation methods

Soil co-contaminated with heavy metals and pesticides has caused large global environmental issues. The interaction of heavy metals and pesticides make the contamination situation more complicated. It is crucial to remediate the co-contaminated soil by heavy metals and pesticides. Bioremediation has the advantages of high efficiency (especially for large, low contamination areas), low cost, easy available, harmless for the ecosystem and high public acceptance, which has been widely developed in remediation of combined pollution of heavy metals and pesticides. This paper reviews the bioremediation applications of combined contaminated soil with heavy metals and pesticides. Abiotic and biotic factors (e.g. pH, temperature, bioavailability of pollutants, the interactions between pollutants, biological competitiveness and biological state) can all affect the bioremediation of heavy metals and pesticides. Meanwhile, the present review summarizes the bioremediation mechanisms of heavy metals and pesticides by microorganisms and plants. The effectiveness evaluation methods of soil remediation are also reviewed. Based on above, this review proposes the future investigations required for this field.