Role of Bioadsorbents in Reducing Toxic Metals

Abstract

Industrialization and urbanization have led to the release of increasing amounts of heavy metals into the environment. Metal ion contamination of drinking water and waste water is a serious ongoing problem especially with high toxic metals such as lead and cadmium and less toxic metals such as copper and zinc. Several biological materials have attracted many researchers and scientists as they offer both cheap and effective removal of heavy metals from waste water. Therefore it is urgent to study and explore all possible sources of agrobased inexpensive adsorbents for their feasibility in the removal of heavy metals. The objective was to study inexpensive adsorbents like various agricultural wastes such as sugarcane bagasse, rice husk, oil palm shell, coconut shell, and coconut husk in eliminating heavy metals from waste water and their utilization possibilities based on our research and literature survey. It also shows the significance of developing and evaluating new potential biosorbents in the near future with higher adsorption capacity and greater reusable options.

Valorization of Food and Agricultural Waste: A Step towards Greener Future

“…These groups possess lone pair of electrons with which they chelate metal ions. Apart from chelation, dye and heavy metal sequestration may occur via various other processes like chelation, complexation, and reduction . Heavy metals are one of the major classes of environmental pollutants, found in the wastewater that are generated from pesticides and chemicals released in water.…”

“…Apart from chelation, dye and 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 heavy metal sequestration may occur via various other processes like chelation, complexation, and reduction. [59] Heavy metals are one of the major classes of environmental pollutants, found in the wastewater that are generated from pesticides and chemicals released in water. Removal of heavy metal contents and inorganic pollutants from waste water can be achieved by several methods.…”

Nuclear fuel cycle, with a liquid ore and fuel: toward renewable energy

“…The complex properties are affected by water temperature (T 10-20 C ), pressure (1 bar), water acidity (pH around 8) and an ionic strength of 0.3 M. Sorbing functional groups are given in Table 1. 16 The species concentrations based on the element composition of seawater are given by calculated output results using thermodynamic data from Ball & Nordstrom, 1991. 17 The tricarbonate complex concentration is 1.25 Â 10 À8 M, and the bicarbonate complex is 1.81 Â 10 À9 M. All other species are well below 1.00 Â 10 À10 M.…”

Heavy Metal Levels in Vegetables Cultivated in Pakistan Soil Irrigated with Untreated Wastewater: Preliminary Results

“…Nowadays, the costly, user-unfriendly, and inefficient conventional methods (e.g., chemical filtration, precipitation, ion exchange separation) used for the removal of metal ions in wastewater are progressively substituted by cost-effective, eco-and user-friendly advanced wastewater treatment techniques (e.g., biosorption, bioaccumulation through phytoremediation and phytomining) [14][15][16]. Indeed, the new methods have been proven to remove these nonbiodegradable toxic wastes more completely (i.e., including those found at low concentrations in high-grade contaminated water) without the need for careful disposal or physical and/or chemical purification processes [14][15][16]. However, it should be emphasized that these methods remain poorly applied in developing countries, such Pakistan, for major reasons that include their availability, the lack of knowledge, training and/or expertise of farmers in these techniques.…”