This review covers research on the use of potassium hydroxide (KOH) to produce and modify activated carbon. The methods employed for activation by considering the activation process, carbonization, temperature, activation time, and KOH ratio to material are described and how the surface area, surface morphology, and functional groups are affected by the KOH ratio. Characterization techniques and preparation conditions are summarized. The activated carbon pore structure mainly depends on the burn‐off size and the time for activation is linked to the overall activation reaction rate. The increase in surface area and pore size depends on the ratio of KOH, showing that KOH affects the surface chemistry of the activated carbon. The sorbent‐sorbate interactions are strongly influenced by different parameters, which were also calculated in this review and used to evaluate such interactions.

Novel African walnut shell (AWS) was treated and improved as an agricultural waste by-product to produce high surface area activated carbon via chemical activation with potassium hydroxide (KOH) to achieve extremely effective adsorptive characteristics for deltamethrin removal. The adsorbent (KOHAWS) was characterized by scanning electron microscopy, Fourier transform infrared (FT-IR) spectroscopy, the Brunauer–Emmett–Teller surface area, and pH point of zero charge (PHPZC). Batch sorption experiments were investigated to study the effect of pH, initial concentration and contact time, sorbent dosage, and agitation speed. The results reveal that the experimental data fitted well with Langmuir isotherm model (R2 = 0.997) with maximum adsorption capacity at 57.64 mg g−1 and the kinetics of the sorption follows the pseudo-first-order model (R2 = 0.995). The sorption of deltamethrin onto KOHAWS reveals a high removal efficiency of 98.2%. The findings show that the novel AWS has excellent regeneration and reusability properties and may be used to remove pesticides from aqueous solutions instead of conventional activated carbon.

Phytochemical and some proximate composition analysis was carried out on three (3) selected edible medicinal plants leaves which were believed to be of medicinal value and have physiological effects as anti-inflammatory, antibacterial, anti-pyretic, antioxidant, laxative etc. The significant aim of the research is to identify the phyto-components as well as compounds presents in the ethanolic extract of Mentha spicata L (mints), Rosemarinus officinalis (Rosemary), and Coriandrum sativum (coriander) using two different analytical methods GC-MS along with their functional groups using FTIR. The GC-MS analysis reveals more than thirty (30) compounds identified as major constituents and mostly all the compounds identified was found to possess medicinal properties. The data analysis from FTIR spectrometry representing most of the strong absorptions bands which further indicates major functional groups such as aliphatic amines, alkanes, aromatic (primary and secondary) and carboxylic acids. While the preliminary phytochemical screening conducted indicates the presence of Flavonoids, tannins, triterpenoids, and saponins from the ethanolic extracts of the plant extracts. Therefore the findings indicate that all the selected plant samples are potential sources of medicinal activities and can be applied in the field of phyto-medicine considering their diverse ethno-pharmacological importance.