Nano/micro-cellulose-based materials as remarkable sorbents for the remediation of agricultural resources from chemical pollutants

Overusing pesticides, fertilizers, and synthetic dyes has significantly increased their presence in various parts of the environment. The transportation of these pollutants into agricultural soil and water through rivers, soils, and groundwater has seriously threatened human and ecosystem health. Applying techniques and materials to clean up agricultural sources from pesticides, heavy metals (HMs), and synthetic dyes (SDs) is one of the major challenges in this century. The sorption technique offers a viable solution to remediate these chemical pollutants (CHPs). Cellulose-based materials have become popular in nano and micro scales because they are widely available, safe to use, biodegradable, and have a significant ability to absorb substances. Nanoscale cellulose-based materials exhibit greater capacity in absorbing pollutants compared to their microscale counterparts because they possess a larger surface area. Many available hydroxyl groups (-OH) and chemical and physical modifications enable the incorporation of CHPs on to cellulose-based materials. Following this potential, this review aims to comprehensively summarize recent advancements in the field of nano- and micro-cellulose-based materials as effective adsorbents for CHPs, given the abundance of cellulosic waste materials from agricultural residues. The recent developments pertaining to the enhancement of the sorption capacity of cellulose-based materials against pesticides, HMs, and SDs, are deliberated.

Adsorption of Heavy Metals Using Mixture of Waste Products

A new adsorbent for removing lead, nickel, chromium and arsenic ions from industrial wastewaters has been investigated. This new adsorbent consists of four waste products tea waste, rice husk, sugarcane bagasse and peanut shell. The adsorbent was prepared without any physical and chemical treatment. Batch experiments were conducted to assess the removal of selected metal ions from wastewaters. The results have shown that the mixture of four waste products presented an excellent adsorption of heavy metal ions. The equilibrium time was dependent on type of adsorbent and sample. The highest percentage of metal ion removal was 100 %. The results showed pseudo second order kinetics. The surface chemical nature of prepared adsorbent was studied by Fourier transform infrared spectroscopy. The functional group present in adsorbent has affinity towards heavy metal ions to form metal complexes. The surface morphology of prepared adsorbent was confirmed by scanning electron microscopy and chemical composition was analyzed by energy dispersive X-ray spectroscopy.