Recently, carbonaceous materials have attracted increasing attention in advanced oxidation processes (AOPs) due to their capability, adaptability and efficiency in the degradation of organic wastewater contaminants with little or no leaching potential. Previous reviews have raised serious controversies regarding the occurrence and mechanism of the persulfate activation process but the detailed influence of the structural features on the persulfate activation performance is yet to be analyzed. This state-of-the-art review aims to discuss the recent structural adjustments, modifications and modulation of carbonaceous materials in relation to how they affect the persulfate activation performance. It was observed that tweaking the carbon structural features (such as the crystal structure and defects, the porous structure, surface area, pore size, and oxygen-containing groups) influences the reaction mechanism, further controlling the persulfate activation process. Hence, different reaction mechanisms involved in the carbon-based persulfate activation process were discussed. Also, the influence of the reaction pathway on the nature of the degradation or intermediate products was examined along with some real water investigations. Environmental application of carbon-based persulfate systems was discussed in relation to its influence on several background ions like Cl⁻, HCO₃ ⁻, CO₃ ²⁻, NO₃ ⁻, SO₄ ²⁻, H₂PO₄ ⁻, natural organic matter (NOM) and humic acid. Furthermore, future research directions for improving the design and properties of carbonaceous catalysts were proposed.

The preservation of meat via sustainable methods and packaging is an area of continued interest driven by the need to address food security. The use of biomaterial films and coatings has gained significant attention due to their non-toxicity and biodegradability compared with conventional synthetic films. Starch and chitosan are sustainable sources for the preparation of films/coatings owing to their relatively low cost, natural abundance derived from numerous sources, biocompatibility, biodegradability, and antimicrobial, antioxidant, and film-forming attributes. These remarkable features have notably increased the shelf life of meat by inhibiting lipid oxidation and microbial activity in food products. Furthermore, recent studies have successfully incorporated binary biopolymer (starch and chitosan) systems to combine their beneficial properties upon composite formation. This literature review from 2020 to the present reveals that chitosan- and starch-based films and coatings have potential to contribute to enhanced food security and safety measures whilst reducing environmental issues and improving sustainability, compared with conventional synthetic materials.

Mild steel is the most common type of metal used in large industries due to its acceptable material properties and low cost. However, a growing concern of its use has been limited as a result of its low resistance to corrosion especially in acidic and alkaline environments. The use of corrosion inhibitors has been encouraged by various researchers as a means slow down the corrosion rate and thus reduce monetary losses to industrial vessels, surfaces and equipment. This paper presents the types of inhibitors employed by different researchers on various mediums. It also seek to consider the limitation processes caused by some factors such as temperature of the media and concentration of the inhibitors and the media. Although the use of green inhibitors has been greatly encouraged due to its low cost but the combination of it with other kinds of inhibitors can prove to boost its effectiveness in corrosion inhibition process. Other organic materials such as animal discharge, and biomaterial should also be considered in future research works. These will further provide more literature to corrosion inhibition of mild steel which in essence promotes the life span of the metal.

Background: Citric acid, aside its uses as a cleaning agent, has varied applications in the chemical, pharmaceutical, and food industries. A biotechnological fermentation process is one of the easiest ways to satisfy the demands for this useful commodity.Methods: The fermentation of pineapple waste byAspergillus nigerfor the production of citric acid was investigated in this study. STATISTICA 8 release 7 (Statsoft, Inc. USA) statistical software was used for the design of experiments, evaluation, and optimization of the process using the central composite design (CCD), a response surface methodology approach. Lower-upper limits of the design for the operating parameters were temperature (25-35^oC), fermentation time (35-96 h), pH (3-6), methanol concentration (1-7%) and glucose (15-85 g/L). Twenty-seven duplicated experimental runs were generated for the CCD route.Results & Conclusion: The optimal operating conditions were validated at 38 g/L of glucose concentration, 3% (v/v) of methanol, 50 h of fermentation time, pH of 4.3 and temperature of 30^oC which yielded15.51 g/L citric acid. The statistical significance of the model was evaluated using a one-way analysis of variance. The validated predicted response values obtained from the statistical model showed close relationships with the experimental data.