Phytoremediation of Arsenic Contaminated Water Using Aquatic, Semi-Aquatic and Submerged Weeds

Abstract

Arsenic (As) is the one the most toxic element present in earth which poses a serious threat to the environment and human health. Arsenic contamination of drinking water in South and Southeast Asia reported one of the most threatening problems that causes serious health hazard of millions of people of India and Bangladesh. Further, use of arsenic contaminated ground water for irrigation purpose causes entry of arsenic in food crops, especially in Rice and other vegetable crops. Currently various chemical technologies utilized for As removal from contaminated water like adsorption and co-precipitation using salts, activated charcoal, ion exchange, membrane filtration etc. are very costly and cannot be used for large scale for drinking and agriculture use. In contrast, phytoremediation utilizes green plats to remove pollutants from contaminated water using various mechanisms such as rhizofiltration, phytoextraction, phytostabilization, phytodegrartion and phytovolatilization. A large numbers of terrestrial and aquatic weed flora have been identified so far having hyper metal, metalloid and organic pollutant removal capacity. Among the terrestrial weed flora Arundo donax, Typha latifolia, Typha angustifolia, Vetivaria zizinoids etc. are the hyper As accumulator. Similarly Eicchornea crassipes (Water hyacinth), Pistia stratiotes (water lettuce), Lemna minor (duck weed), Hyrdilla verticillata, Ceratophyllum demersum, Spirodella polyrhiza, Azola, Wolfia spp., etc. are also capable to extract higher amount of arsenic from contaminated water. These weed flora having As tolerance mechanism in their system and thus remediate As contaminated water vis-à-vis continue their life cycle. In this chapter we will discuss about As extraction potential of various aquatic and semi aquatic weeds from contaminated water, their tolerance mechanism, future scope and their application in future world mitigating As contamination in water resources.

Decontamination of Arsenic and Manganese in Polluted Water by Canary Seed Plant (Phalaris arundinacea L.) in Saturated Sand Culture

“…Background and Objectives: Phytoremediation through constructed wetlands stands out as environmentally friendly method for eliminating heavy metals from aquatic environments (Priyanka et al, 2017). The removal efficiency (RE) in these systems highly depends on the culture media, dissolved oxygen (DO), type of flow, hydraulic retention time (HRT) and plant species (Roy et al, 2022). The time to reach maximum absorption (Absmax) and maximum RE are the two basic criteria in the evaluation of phytoremediation plans.…”