Bioaugmentation as a green technology for hydrocarbon pollution remediation. Problems and prospects.

Environmental pollution mitigation measure involving bioremediation technology is a sustainable intervention for a greener ecosystem biorecovery, especially the obnoxious hydrocarbons, xenobiotics, and other environmental pollutants induced by anthropogenic stressors. Several successful case studies have provided evidence to this paradigm including the putative adoption that the technology is eco-friendly, cost-effective, and shows a high tendency for total contaminants mineralization into innocuous bye-products. The present review reports advances in bioremediation, types, and strategies conventionally adopted in contaminant clean-up. It identified that natural attenuation and biostimulation are faced with notable limitations including the poor remedial outcome under the natural attenuation system and the residual contamination occasion following a biostimulation operation. It remarks that the use of genetically engineered microorganisms shows a potentially promising insight as a prudent remedial approach but is currently challenged by few ethical restrictions and the rural unavailability of the technology. It underscores that bioaugmentation, particularly the use of high cell density assemblages referred to as microbial consortia possess promising remedial prospects thus offers a more sustainable environmental security. The authors, therefore, recommend bioaugmentation for large scale contaminated sites in regions where environmental degradation is commonplace.

Prospects of emerging PAH sources and remediation technologies: insights from Africa.

Remediation of polluted environmental media is critical to realization of the goals of the United Nations Decade on Ecosystem Restoration (UNDER) project. Many natural-resource dependent economies in Africa are characterized by numerous contaminated sites resulting from conventional and artisanal natural-resource mining. Alongside these extractive activities, there are refining, processing, and power plant operations, agriculture, urban, and infrastructure developments that contribute to increased discharges of toxins into the environment, particularly polycyclic aromatic hydrocarbons (PAHs), which are carcinogenic in nature. As a result, human and environmental receptors (i.e., air, water, soil, and biota) face increasing risk of exposure to higher concentrations of PAH. Evidence exists of widespread PAH contamination and in some instances where corrective action has been taken, residual contaminant levels exceeding regulatory thresholds remain in the environment due to the use of inappropriate and unsustainable remedial methods. Considering the long-term harmful effects of PAH on human and ecosystem health, land use, and the complexity of Africa's environmental deterioration, it is essential to explore remediation strategies that benefit both the environment and the economy. This review examined the status, opportunities, and challenges related to the application of emerging green technologies to remediate PAH-contaminated sites in five African countries (South Africa, Nigeria, Angola, Egypt, and Kenya). This paper concludes that bioremediation presents a sustainable option, considering its low net emissions and environmental footprints, and its low economic cost to Africa's poor communities and overburdened economy. However, an integration of biological and physico-chemical approaches could address various compounds and concentrations of PAH contamination.

Assessment of mold contamination and physicochemical properties of crude palm oil sold in Jos, Nigeria.

Due to increasing reports on poor-quality palm oil in the market, there has been a continual decrease in demand and revenue cum product rejection of palm oil sold in Jos, Nigeria. Hence, the significance of this work aims to moderate the microbial and physical qualities of crude palm oil sold in different major markets in order to increase revenue through quality control and quality assurance protocols. The intent is to create awareness among government monitoring agencies, buyers (exporters and importers), and to promote standard processing procedures among manufacturers. The study was carried out to ascertain the levels of mold contamination and physicochemical properties of crude palm oil sold in Jos and its environ. A total of 90 samples were collected in sterile containers. Molds were isolated and identified using standard identification procedures. The physicochemical properties: free fatty acids (FFA), peroxide value (PV), iodine value (IV), moisture content (MC), and impurity level were determined. The assessment of mold isolated from the study sites recognized some life-threatening genera capable of producing carcinogenic toxins. Candida sp. (51%) had the highest percentage of occurrence followed by Aspergillus sp. (45%) while Fusarium sp. (3%) was the least occurring mold. The mean mold count for all the palm oil samples ranges from 3.18 × 104 (cfu/mL)-4.56 × 104 (cfu/mL). Physicochemical findings showed that the average FFA (3.43-6.88%), PV (6.96-13.63 mEq/kg), IV (39.7-67.5 wijs), and MC (0.44-0.72%) values were within the SON acceptable limit, except the impurity level (0.28-0.44%) which was higher than the acceptable SON range in all the sites. There was a significant difference (P ≤ 0.05) in the mold and physicochemical properties of crude palm oil in almost all the samples analyzed when compared to both local and international permissible limits of the tested parameters recommended for edible palm oil. There was compliance between the permissible limits (local and international) of the physicochemical values of the parameters we tested for in the edible palm oil except the impurity level, while the mold count did not meet (was higher) with the required permissible limit of the SON mold count.