Lignocellulosic-Based Sorbents: A Review

The combustion of fossil fuels is intensifying global warming and destructing the ecosystem with negative human health impacts as well. Even so, other anthropogenic activities have unfortunately constituted pollution also to our environment, say, in the form of waste waters. Beside these, the existing technologies for waste water treatment have problems such as high costs, sludge disposal challenges, etc. Thus, it is now important to find economically viable and safe alternatives to decontaminate waste waters. Hence, low cost, renewable, easily accessible, and readily prepared biosorbents have become favourable alternatives to traditional counterpart for the elimination of pollutants from aqueous systems. Fortunately, these biosorbents also have requisite and comparable properties necessary for adsorption of pollutants. Many studies have been reported on the application of biosorbents for pollutants removal. However, this paper provides an overview of biosorbents preparation, properties, their applications in pollutants removal and related use. Biosorbents are usually used in raw or processed forms such as activated carbon (AC), biobar (BC), and charcoal (CC) for removal of pharmaceuticals, pesticides, organics, inorganics, mycotoxins, etc. from aqueous systems. Besides classical sorption of the pollutants, biosorbents have prospect of applications as electrodes in the microbial fuel cells, green packaging materials, energy storage devices, catalysts, soil remediation agent, carbon sequestration, etc. Hence, further concerted investigations should be exercised to develop feasibly best conditions for the preparations and modifications of biosorbents. In addition, mean pore size, pore size distribution, porosity, surface functionality, and zeta potential studies are necessary to be had about biosorbents, especially novel types. There is need for development of biosorbents for specific tasks. Another essential thing is to determine desorption studies of these novel biosorbents. Focus should also be directed on more economically viable and sustainable biosorbents to enhance their use. Again, it is suggested that more suitable biomasses be identified to enable successful preparation of efficient biosorbents. More so, biosorbents can be recycled after use to avoid littering and possible pollution.