Biosorbents Removed Copper Heavy Metal from Agricultural Land Cultivated with Vigna radiata (Mung Bean)

Abstract

Background. Heavy metals in excessive levels are hazardous to ecosystems as they can bioaccumulate in organisms, have toxic effects on biota, and even cause mortality in most life forms. Methodology. The present study consists of two studies; initially, different concentrations of copper were biosorbed by using 1 gm powder of various biosorbents such as orange peels (OP), pomegranate peels (POP), and peanut peels (PP). Furthermore, the biosorbed water was used to irrigate soil when the mung beans were cultivated. The growth parameters of plants growing under induced copper stress and treated with different bioabsorbed waters were also evaluated. Results. The results revealed that, among all biosorbents, the copper biosorption capacity of orange peels was maximum (90%), followed by pomegranate peel. The results of the second experiment exhibited that the plants irrigated with biosorbed water did not show metal toxicity. A remarkable increase in shoot length, shoot fresh weight, and shoot dry weight was observed (29.8 cm, 15.4 g, and 14 g, respectively) when exposed to biosorbent water with peanut peels + 200 mg kg−1 (Cu2+). Similarly, pomegranate peel biosorbed water turned out to be an effective treatment to enhance root length, root fresh weight, and root dry weight (6.81 cm, 4.07 g, and 2.66 g, respectively) and resist against induced heavy metal stress conditions at higher concentration (200 mg kg−1). Furthermore, orange peel biosorbed water elevated the total chlorophyll content and soluble sugar content in mung bean (1.56 mg/g and 1.89 mg/g). The highest tolerance index of mung bean plant grown under the stress of Cu2+ metal was induced by orange peel biosorbed water. Conclusion. Biosorption is an environmentally friendly approach to mitigate heavy metals from the water. The studies showed that agricultural wastes have enough bioabsorption potential and should be used to absorb the heavy metal present in water.