A review of the status, challenges, trends, and prospects of groundwater quality assessment in Nigeria: an evidence-based meta-analysis approach.

With the imminent industrial growth and population increase, Nigeria will continue to experience significant shifts in the quality of water, with a rise in emerging contaminants. This will increase the irregularity and complexity of the water quality information. Therefore, using the PRISMA meta-analysis approach, this review systematically identified the commonly used water quality assessment techniques in Nigeria, the drawback in the application of these techniques as well as the gaps in the area of water quality assessment and monitoring from 2003 to 2023. Recommendations were also made based on the evaluation of a new research direction; through the review of the effectiveness of advanced techniques for monitoring water quality in Nigeria. Sixty-eight published articles were chosen for the meta-analysis while the VOSviewer program was used to perform bibliographic coupling and visualization. The review revealed that the application of machine learning in water quality prediction has not been well explored in Nigeria. This is attributed to limited data availability and poor funding by the government. It was found that southwestern Nigeria has a greater amount of research on groundwater quality monitoring and evaluation than other regions. The variability was explained by variations in the underlying geology, aquifer features; variability in anthropogenic activities, and level of literacy among various geopolitical zones. Further studies should focus on the application of soft-computing and integrated biomonitoring techniques for effective prediction and monitoring of emerging contaminants for improved water quality. Effective collaboration between environmental stakeholders and government agencies is recommended for effective water resource sustainability.

Substrate specificity of a new laccase from Trametes polyzona WRF03.

Various aromatic compounds that are structurally analogous to lignin were tested as possible/preferred substrates for purified laccase from newly isolated white rote fungi, Trametes polyzona WRF03. The pH optima were tested using different substrates and kinetic studies were conducted at these pH optima. The pH optima in the presence of ABTS, α-naphthol, o-dianisidine, and catechol were 4.5 but 5.0 and 5.5 in the presence of guaiacol and pyrogallol, respectively. The initial velocities obtained from the kinetic study were analyzed using Graph Pad Prism 7 and Lineweaver-Burk plot to obtain kinetic constants (k m and Vmax) which were used to calculate substrate specificity. Amongst all the substrates tested, ABTS had the highest specificity-constant (181.51 M-1s-1), and therefore, the most preferred substrate was followed by α-naphthol, o-dianisidine, guaiacol, pyrogallol, and catechol. Resorcinol, orcinol, and veratryl alcohol did not display any considerable chemical shift in the presence of Trametes polyzona WRF03 laccase. Also, oxidation of phenolic substrates appeared to be dependent on the nature of the substituent groups and their relative position on the aromatic nucleus. Since most of these substrates are structural analogs of lignin and many recalcitrant environmental pollutants, the enzyme may find application in delignification, treatment of wastewater containing dyes, and polycyclic aromatic hydrocarbons (PAHs).