Clay minerals have been recognized as one of the cheap and effective materials for wastewater remediation. Among the various clay minerals, montmorillonite (MMT) has received much attention due to its wide availability, low-cost and promising properties such as high porosity, mechanical strength, and cation exchange capacity. Additionally, MMT has high swelling properties. These features make it an ideal material for wastewater remediation applications. In addition, it possessed good cationic exchange capacity, making it easier to interact with various molecules. MMT and its composites exhibited good selectivity and catalytic activity for contaminants elimination from wastewater. Surface modification and functionalization have been identified as a way to improve the MMT’s adsorptive performance and endow it with light and light-harnessing properties. Thus, MMT composites, especially metal and metal-oxide nanoparticles, have shown good adsorption and photocatalytic activity toward the elimination/mineralization of various contaminants such as dyes, pharmaceuticals, heavy metals, and other organic and inorganic species. As such, MMT and its composites can be adopted as potential materials for wastewater remediation.

Over the last century, there has been increasing debate concerning the use of biomass for different purposes such as foods, feeds, energy fuels, heating, cooling and most importantly biorefinery feedstock. The biorefinery products were aimed to replace fossil fuels and chemicals as they are renewable form of energy. Biomass is a biodegradable product from agricultural wastes and residues, forestry and aquaculture. Biomass could be sourced from a variety of raw materials such as wood and wood processing by-products, manure, fractions of organic waste products and agricultural crops. As a form of renewable energy, they have the advantages of easy storage, transportation, flexible load utilization and versatile applications. The aim of this study is to provide an overview for thermochemical and biochemical biomass conversion technologies that were employed currently. Attention was also paid to manufacture of biofuels because of their potentials as key market for large-scale green sustainable biomass product.

In this study, activated carbon from oil palm shell was produced by two-step chemical activation using K₂CO₃ as the chemical activant in the ratio 1:2 for the removal of phenol in a fixed-bed column. The characterization of the carbon was carried by Fourier Transform Infrared spectroscopy, Scanning electron microscope, thermogravimetric analysis, zeta potential, Brunauer–Emmett–Teller (BET) surface area, Elemental and Proximate analysis. The Langmuir surface area, BET surface area, and pore volume of the carbon were 817 m²/g, 707 m²/g, and 0.31 cm³/g, respectively. The examination of several factors including bed depth, initial phenol concentration, and flow rate were carried out at constant pH of 6.5. The maximum sorption capacity of the carbon for phenol was 238.12 at 250 mg/L initial phenol concentration, 1 cm bed depth, and 9 mL/min flow rate. Thermodynamic parameters were determined to analyze the behavior of phenol uptake at different temperatures. Breakthrough curve models indicated that Yoon–Nelson model fitted the experimental data better than Adams–Bohart and Thomas models. According to the results obtained, activated carbon prepared from oil palm shell, modified with ammonia solution was an effective, sustainable, low cost, and alternative adsorbent for the removal of phenol in aqueous solutions.