The Role of Inorganic Metal Salts in Wastewater Clarification

An investigation into the ability of four inorganic coagulants namely; alum (Al2(SO4)3.18H2O), ammonium aluminum sulphate (NH4Al(SO4)2.12H2O), ferrous sulphate (FeSO4) and ammonium ferrous sulphate (NH4)2Fe(SO4)2.6H2O) in clarifying wastewater was examined. Results obtained from conventional standard ‘jar-test’ experiments indicated that alum was the most effective coagulant since it reduced turbidity of the wastewater to 0.64 NTU at a contact time of 300 min. Ferrous sulphate was the least effective coagulant, reducing turbidity of the wastewater to 3.45 NTU only at 240 min contact time, but when the contact time of the experiment was increased from 240 to 300 min, re-coloration of the solution was observed indicating re-stabilization of suspended particles. These findings tend to support the claim that alum is a choice coagulant for wastewater clarification.  Â

The causal relationship between Foreign Direct Investment (FDI) and the macro-economy of selected west African countries: Panel ARDL/Granger Causality Analysis

This study examined the long run and short run dynamic relationships between macroeconomic variables and FDI in West Africa using recent econometric techniques for Granger non-causality and PMG/ARDL for period of 1990 to 2016. Controlling for the influence of trade openness and exchange rate, the long-run effect of Foreign Direct Investment (FDI) on economic growth and gds are found to be positive and statistically significant. FDI is found to be negative and statistically significant on unemployment indicating that an increase in FDI would significantly reduce unemployment in the selected West African nations in the long-run. The coefficient of error correction model in all the specifications is negative and significant indicating that the short-run disequilibrium is corrected in the long-run. Panel Granger causality tests result indicates that causality do not run from any direction in the short run which could be attributed to poor economic activities among this developing countries and an important revelation for policy implication.Keywords/Phrases: Foreign Direct Investment (FDI), West Africa, PMG/ARDL, cointegration, Granger causality, macroeconomic variable

Seasonal variation of the hydro-environmental factors and phytoplankton community around waters in Tincan Island, Lagos State, Nigeria

The phytoplankton diversity, pigment, abundance and distribution in relation to physico-chemical parameters were studied from four stations for a period of five months (May – September 2018) and were analysed using standard procedures. Rainfall was highest (329.5 mm) in September and lowest (142.7 mm) in July. The total suspended solid (TSS) had a mean value of 63.10±12.81 mg/L and the total dissolved solids (TDS) had the highest value of 15189 mg/L in May which was not significantly different around the sampling points {P > 0.05}. The pH and nitrate level recorded had a mean value of 7.25±0.33 and 3.11±1.33 mg/L respectively. Microscopic identification revealed a total of 129 species belonging to 62 genera, 22 families and five divisions in the following order of specie abundance: Bacillariophyceae (65 taxa) > Cyanophyceae (27 taxa) > Chlorophyta (20 taxa) > Dinophyceae (10 taxa) > Euglenophyceae (7 taxa). The high dominance of Microcystis aeruginosa observed was indicative of organic pollution. The range of community structure indices were as follows: Margalef Index (0.1406 – 5.295) and Shannon – Weiner Index (0.02644 - 0.4979). The relatively high nutrient status favours the high abundance of phytoplankton which is understood to be deleterious to the ecosystem. Municipal wastes must be treated or recycled before discharge and a continuous environmental surveillance is required to maintain the biological integrity of this area. Keywords: Phytoplankton, Physicochemical Parameters, Nutrient Status and Tincan Islan