Eco-friendly Alternatives for the Removal of Heavy Metal Using Dry Biomass of Weeds and Study the Mechanism Involved

Abstract

Metal contamination issues are becoming increasing day by day common in India and elsewhere, with many documented cases of metal toxicity in mining industries, foundaries, smelters, coal-burning power plants and agriculture. Heavy metals, such as cadmium, copper, lead; chromium and mercury are major environmental pollutants, particularly in areas with high anthropogenic pressure causing increased depositions of heavy metals in the terrestrial and aquatic environment. The release of these pollutants without proper treatment poses a significant threat to both environment and public health, as they are non-biodegradable and continual. Thus, their treatment becomes inevitable and in this endeavor, absorption seems to be a promising alternative for treating metal contaminated waters. In the present study two plants, one macrophyte Eichhornia crassipes and other terrestrial Canna indica are used as adsorbents to study the process of biosorption. The studied plants have not gained much importance and are found in abundance in the Indian climate. Also the former has been declared as a weed and its management has become a great problem so with the study the plants can be better and further utilized for wastewater treatment for the removal of metal ions and other impurities. For the present study multi species solution of four heavy metals i.e. cadmium, chromium, lead and zinc are tested for the adsorption by the selected bio sorbent. This technology out-performs its predecessors not only due to its cost effectiveness but also in being eco-friendly i.e., where other alternatives fail. Journal of Bior emediation & Biodegradation

Removal of Cu (II) ion from Ezana (Meli) Gold Mining Wastewater Using Eucalyptus Bark as Adsorbent

“…The preparation of Bark of Eucalyptus tree species which were collected from the local area Addis Ababa and washed dried using oven and ground into small particles size [4], in these studies the sample was crushed manually into a small pieces and dried in sun light for 3days. It was then washed by distilled water to remove some foreign materials (dusts).…”

“…The description how pollutants relate with the adsorbent materials, expression of the surface properties, abilities (capacity) of adsorbents, effective design of the adsorption systems. Thus, are critical for optimization of the adsorption mechanism pathways [4]. In this study, the experimental result was analyzed against two isotherm equations (Langmuir and Freundlich).…”

“…Even if, the desorption efficiency increased with an increase in the concentration from 0.1M of the agent (HCL, H2SO4 and HNO3) after some time the bio sorbent deteriorating at higher concentration of the same and it was noticed that HCl gave maximum desorption (99%) as compared to H2SO4 (83%), HNO3 (74%) and H2O2 [4]. This desorption experiments were carried out by batch mode and efficiencies have been compared with each other of the solvent.…”

“…Copper was selected as potential contaminant due to its maximum concentration than other element i.e. Cu (8360 to 59280 ppm) and Pb (6.4 to 1652 ppm) of Ezana (Meli) [4]. Sulfuric acid was used to treat eucalyptus bark for removal of lignin which packs the cellulose and it increases the carboxyl active groups which are used for increasing the adsorption efficiency [5].…”

“…Sulfuric acid was used to treat eucalyptus bark for removal of lignin which packs the cellulose and it increases the carboxyl active groups which are used for increasing the adsorption efficiency [5]. The bio adsorbents have The affinity for heavy metal ions to form metal complexes or chelates through their functional groups like carboxyl, hydroxyl, phosphate, sulfate, thioether, phenol and carbonyl amide have the behavior of the bio adsorbent [4]. The effect of physical parameters such as pH, adsorbent dosage and contacting time was investigated to examine the efficiency of eucalyptus bark.…”