This paper investigated the analyses of removal of Methylene Blue (MB) and Brilliant Green (BG) dyes from aqueous solutions by adsorption on activated carbon prepared by chemical activation of coconut shell, eucalyptus tree, corn cob and flamboyant pod. It was found that the carbon pores increased after carbonization and activation processes. The maximum percentage MB removal was obtained as 95.0% for coconut shell, 93.2% for eucalyptus tree, 99.9% for corn cob, and 99.7% for flamboyant pod. Also, the maximum percentage BG removal was obtained as 97.0% for coconut shell, 98.2% for eucalyptus tree, 99.6% for corn cob, and 99.6% for flamboyant pod. The adsorption isotherms of the adsorption process were studied, and Freundlich model showed the best fit with the equilibrium data. To optimize the operating conditions, the effects of contact time, adsorbent dosage, and pH were investigated by two levels of factorial experimental design method and adsorbent dosage was found as the most significant factor.

Bacterial diseases are the most common diseases among cultured fish. Aeromonas hydrophila considered the most important freshwater bacterial fish pathogen. Early diagnosis considered the cornerstone in controlling the disease. Biochemical method is laborious, expensive and time consuming whereas agglutination test is simple, rapid, accurate inexpensive and the test can be performed in field conditions. In the present study, agglutination test was established for diagnosis A. hydrophila infection in Oreochromis niloticus. A. hydrophila was isolated from naturally infected fish then distracted to subunits somatic and flagellar antigens. The prepared antigen was reacted with positive antisera of A. hydrophila which produced distinct tiny clumps. The sensitivity and specificity of slide agglutination test against collected sera were 90%, 77.5% respectively in case of somatic antigen and 92.5%, 72.5% in case of flagellar antigen. It could be concluded that agglutination test can be used as screen test for diagnosis of A.hydrophila infection in fish farms and the method can be diagramed on other bacteria.

Open dumping and uncontrolled landfilling of solid wastes are the most widely practiced waste disposal methods in many cities of the less-developed regions, especially those in sub Saharan Africa. These practices are unsustainable and pose a major threat to the environment and public health. Of particular concern is the leachate produced at the disposal sites, which is concentrated with biological and chemical substances that could contaminate the soil, surface and groundwater sources in the environs. The effects of leachate percolation on the quality of groundwater sources is of great concern especially in sub Saharan Africa, where untreated self-supply groundwater options represent a major source of water supply for many inhabitants. Given this perspective, the physicochemical characteristics of some groundwater samples from wells around a major waste disposal site; Gyadi-gyadi in Kano metropolis, Nigeria, were examined. The samples were collected from the north, east, south and west directions around the disposal site and analysed for parameters that include: pH, turbidity, total dissolved solids, electrical conductivity, total alkalinity, total hardness, Ca 2+ , Mg 2+ , Na + , K + , NO 3-, SO 4 2-, Cl-, Cu 2+ , Fe 2+ and Mn 2+. Significant concentrations of most parameters were revealed, often above the WHO recommended thresholds. Accordingly, some measures were highlighted towards protecting, preserving and sustaining groundwater quality as a strategic source of water supply in the area and beyond.

Hazardous wastes are substances that are no longer needed and have no current or perceived value at a given time or place. Many of the materials used or produced in chemical processes possess hazardous properties. The key hazardous wastes sources include industrial, medical, and household wastes, and occur in solid, liquid, or gaseous states. These are wastes that are classified and/or have intrinsic or inbuilt chemical and physical distinctiveness of toxicity, ignitability, corrosivity, and reactivity. Managing hazardous wastes is of immense significance to human, economic, social and environmental health conditions. Hazardous wastes management practice in Nigeria is not in consonance with the best global practices. Many hazardous wastes are dumped indiscriminately, which constitutes hazard to the environment and posed public health concerns. This study analysed the strength, weaknesses, opportunities and threats of hazardous wastes management in Nigeria. There are various environmental regulations on hazardous wastes in the country, but implementation remains a challenge, as such there is need for more proactive measures to be taken towards sustainable solutions to the problems.

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