Water Hyacinth (Eichhornia crassipes) A Sustainable Strategy for Heavy Metals Removal from Contaminated Waterbodies

Abstract

Heavy metal and metalloid (HM) driven water pollution is of great global concern, leading to ecological health risks via bioaccumulation and biomagnification due to its high solubility in aquatic environments. There are varying sources of HM pollution that can lead to the contamination of water bodies; the treatment of this wastewater, through various physical and chemical methods, is costly, energy intensive, and often inappropriate for the large quantities of contaminated waters produced. Phytoremediation using aquatic plants and weeds offers an ecologically sustainable approach for the bioremediation of wastewaters. Using the deleterious aquatic weed, water hyacinth (Eichhornia crassipes) for the bioremediation of HM in contaminated water bodies is a promising tool with potential for post-utilization as a source of bio-energy generation. Remediation via water hyacinth is a sustainable strategy for removing HM, i.e. Zn, As, Pb, Cu, Cd, Ni, Cr, Hg, etc., from different contaminated water bodies and demonstrates a rapid growth in a eutrophicated and polluted environment. Water hyacinth can efficiently entrap both organic and inorganic pollutants from various types of wastewater, utilizing its dense root systems. The absorption mechanisms of water hyacinth’s root system are versatile, including ionic exchange, chelation, or coordination. With their bio-film forming capability, root colonizing microbes can act as a snare for HM by signaling function mechanism. Water hyacinth can be utilized post-remediation to produce bioenergy such as charcoal, biogas, and bio-fertilizer production, increasing the value of the product and ensuring the process is sustainable. This chapter illustrates how managing aquatic weeds such as water hyacinths can provide sustainable phytoremediation of contaminated waters and renewable green energy resources.