A Review on Modification Methods of Adsorbents for Naphthalene in Environment

A review of pre- and post-surface-modified neem (Azadirachta indica) biomass adsorbent: Surface functionalization mechanism and application

In contemporary wastewater treatment industry, advanced oxidation techniques, membrane filtration, ion exchange, and reverse osmosis are used to treat chemically loaded wastewater. All these methods required highly toxic oxidizing chemicals, high capital investment in membrane/filter materials, and the installation of sophisticated equipment. Wastewater treatment through an adsorption process using biomass-based adsorbent is economical, user-friendly, and sustainable. Neem tree waste has been explored as an adsorbent for wastewater treatment. The chemical components in the neem biomass include carbohydrates, fat, fiber, cellulose, hemicellulose, and lignin, which support the functionalization of neem biomass. Moreover, adsorbent preparation from renewable resources is not only cost-effective and environmentally friendly but also helps in waste management for sustainable growth. Contemporary researchers explored the pre- and post-surface-modified neem biomass adsorbents in scavenging the pollutants from contaminated water. This review extensively explores the activation process of neem biomass, physical and chemical methods of surface modification mechanism, and the factors affecting surface modification. The pollutant removal through pre and post-surface-modified neem biomass adsorbents was also summarized. Furthermore, it also provides a comprehensive summary of the factors that affect the adsorption performance of the neem biomass-derived adsorbents against dyes, metal ions, and other emerging pollutants. Understanding the surface-modification mechanisms and the adsorption efficiency factor of adsorbents will help in harnessing their potential for more efficiently combatting environmental pollution and making strides toward a greener and more sustainable future.

Recent insights into mechanism of modified bio-adsorbents for the remediation of environmental pollutants

Rapid industrialization has exacerbated the hazard to health and the environment. Wide spectrums of contaminants pose numerous risks, necessitating their disposal and treatment. There is a need for further remediation methods since pollutant residues cannot be entirely eradicated by traditional treatment techniques. Bio-adsorbents are gaining popularity due to their eco-friendly approach, broad applicability, and improved functional and surface characteristics. Adsorbents that have been modified have improved qualities that aid in their adsorptive nature. Adsorption, ion exchange, chelation, surface precipitation, microbial uptake, physical entrapment, biodegradation, redox reactions, and electrostatic interactions are some of the processes that participate in the removal mechanism of biosorbents. These processes can vary depending on the particular biosorbent and the type of pollutants being targeted. The systematic review focuses on the many modification approaches used to remove environmental contaminants. Different modification or activation strategies can be used depending on the type of bio-adsorbent and pollutant to be remediated. Physical activation procedures such as ultrasonication and pyrolysis are more commonly used to modify bio-adsorbents. Ultrasonication process improves the adsorption efficiency by 15-25%. Acid and alkali modified procedures are the most effective chemical activation strategies for adsorbent modification for pollution removal. Chemical modification increases the removal to around 95-99%. The biological technique involving microbial culture is an emerging field that needs to be investigated further for pollutant removal. A short evaluation of modified adsorbents with multi-pollutant adsorption capability that have been better eliminated throughout the adsorption process has been provided.