: Reducing the Toxicity of Heavy Metals

Water covers about 70% of the earth’s surface and is essential for life (Wang et al., 2020), out of which only 3% is fresh and only 0.5% drinkable. Water is single largest component of human body and comprises nearly 60% of it. (Zhou & Chen, 2018). Its excessive and ever increasing use in all fields of life has made Fresh water shortage a global threat. Only 33% of the world's total population has access to standard-quality freshwater. Water is being polluted from a variety of sources, from domestic to industrial level. Contaminants in this polluted water involve heavy metals as well that leads to serious adverse effects on the lives to which the water is being served (Obinna & Ebere, 2019). Considerable fraction of this polluted water is being used as untreated in irrigation (Sarwar et al., 2020).This contaminated water has high concentration of Nitrogen and Phosphorus , and that’s why its use in irrigation is increasing gradually (Zhang & Shen, 2019) . As this waste water is contaminated with heavy metals including; Arsenic (As), Cadmium (Cd), Nickel (Ni), Mercury (Hg), Chromium (Cr), Zinc (Zn), and Lead (Pb) and has become a serious health issue for men, plants and animals. (Rehman et al., 2018). These heavy metals present in waste water are not only toxic but are non-biodegradable which make their presence even worse. When this heavy metals containing water is used for irrigation, they enter into the plants and vegetables, where they do not have any significant biological role but causes various adverse effects to them (Chaoua et al., 2019). Their bioaccumulation in plants has reported to inhibit the growth of the plants (Kamran et al., 2020) Bioaccumulation of various heavy metals such as arsenic, mercury, lead and chromium will tear down the metabolic processes involved in the human body. These fruit based absorbents act as precursor of activated carbon and contain other functional groups that helps to adsorb the heavy metals from water. These functional groups (- COOH, -OH, - NH2) present in bio absorbents make a thin film of heavy metals on them (Mallampati et al., 2015) 2011). In this study, peels of different plants i.e Bitter Apple, Cucumber, Persimmon, unripe orange and activated carbon from used dry cell were used. Organic functional groups present in them adsorb the heavy metals and reduces their concentration. Moreover, Activated Carbon which has proved to be a versatile adsorbent and a potential candidate in treatment of waste water was also used. Results from all above materials were separately obtained and comparatively analyzed which was very helpful in explaining their efficiency.