Phytoremediation of Cadmium: A Review

Cadmium (Cd) is a highly poisonous heavy metal that presents a considerable hazard to the environment and human health. It can move from water to soil, then food crops and accumulate in their edible parts. When it becomes part of the food chain, it causes toxic effects to human life via kidney damage to even cancers. Numerous methods have shown varied efficacies for its remediation from contaminated environments. One method that has shown promising results with sustainable Cd removal is phytoremediation, which involves phytoextraction, rhizofiltration, phytostabilization, and phytostimulation through diverse plant species. Based on Cd uptake in aerial part of plant three types of plants are existed and exploited for phytoremdiation such as hyperaccumulator (concentrate substantial amount of Cd in shoot with BCF > 1), excluder (concentrate tiny amount of Cd in shoot with BCF < 1), and indicator plants (concentrate reasonable amount of Cd in shoot with BCF = 1). Numerous plant species have been exploited for remediation of Cd in water (Eichhornia crassipes, Pistia stratiotes, Lemna minor), whereas in soil (Brassica spp., Sedum alfredii, Populus alba, Alyssum murale, Helianthus annuus, Thlaspi caerulescens, Zea mays). This chapter critically reviewed the sources, and toxicity of Cd. Finally, selection criteria of plant, merits and demerits and types of phytoremediation elaborated in detail for remediation of Cd contaminated water and soil resources for achieving sustainable development.