INTRODUCTIONIndustriessuch as textile, paper, leather plastic to mention a few, plays an importantrole in economic development but the disposal of waste waters from theseindustries into the environment is of great concern for toxicological reasons 1.Textile waste waters are highly coloured and consist of different types oforganic compound and toxic substances which are of great threat to human’shealth and aquatic organisms. The dyes from these waste waters are stable tolight and are incapable of being digested by bacteria therefore decreasinglight permeability causing a negative effect on photosynthesis 2. Therefore the removal of such dyes fromtextile waters is of interest due to their impact on receiving waters 1.variousmethods of removing dyes from textile waste waters have been studied and they includeelectro chemical, coagulation, oxidising agents, precipitation, photocatalysis,flocculation, adsorption etc.
2,3,4,5,. Adsorption is consideredas the most efficient method because it is cheap, easy to carry out andabundance of adsorbent materials 2. The technique depends onhigher specific surface area, porosity and narrow particle size distribution ofthe adsorbent 6. Different kinds of activated carbon have beenused in many studies as adsorbents because of their adsorption capacity; theyare highly porous and have high surface area to volume ratio. For example coirpith carbon (Kavitha et al 2007), Periwinkle shells (Bello et al 2008), Bamboodust, coconut, ground nut shell, rice husk and straw (Kannan et al 2001), scraptyres, bituminous wastes and coal (Acevedo et al 2015) etc.
In this study coal obtained from Morupule minewas activated using Hydrochloric acid and was used as an adsorbent for removalof methylene blue from its aqueous solution. Activated coal qualifies to be oneof the materials used as adsorbents because it has good porosity and highsurface area for adsorption. The coal obtained from Morupule mine is mainlyused in thermal power stations for generating electricity and also as reducingagents, therefore using the coal for waste water treatment will be an addedadvantage to the country.
Methyleneblue is one of the dyes used in textile industries for dyeing materials. Thedye has negative impact to human’s life i.e. result in eye burns which may lead to permanent injury to human, whileinhalation can result in short period of rapid or difficult breathing (Tan etal 2008).
Ingestion of the dye lead to symptoms like burning sensation,vomiting, nausea and diarrhoea (Bhattacharyya et al 2005).