Fresh water is vital to human life and economic well-being, and societies extract vast quantities of water from rivers, lakes, wetlands, and underground aquifers but most of these freshwater sources are polluted by different chemicals discharged from industries. Our need for fresh water has long caused us to overlook equally vital benefits of water that remains in streams to sustain healthy freshwater habitats.Heavy metals are discharged from different industries into freshwaters and are easily absorbed by fish and other aquatic organisms. Small concentrations can be toxic because heavy metals undergo bio concentration. Chromium is an essential element that is required in small amounts for carbohydrate metabolism, but becomes toxic at higher concentrations. The most bioavailable and therefore most toxic form of chromium is the hexavalent Cr (VI) ion. It is well recognized as an element of environmental and public health concern. The objective of this study was to examine the potential of coffee husk in removing chromium from polluted water.In this study, the adsorption potential of activated carbon for the removal of Cr (VI) ions from industrial wastewater has been investigated. The adsorption of hexavalent chromium from aqueous solution by coffee husk activated carbon prepared by chemical method and its application to real wastewater was studied. The extent of adsorption was studied as a function of pH, contact time, adsorbent dose, and initial adsorbed concentration. Optimum results were found to be 60 min, 80 mg/l, 2 g/l, 3 g/l and 200 rpm for time contact, initial concentration, pH, adsorbent dose and stirring speed respectively at the optimal condition the adsorption of hexavalent chromium was found to be 98.19%.

IntroductionIndustrialization is seen as a motor behind many of the processes usually termed "social transformation" and "modernization". Paint industry is one of the industries that cause the water pollution. Wastewater is generated primarily due to cleaning operations of mixers, reactors, blenders, packing machines and floors. Heavy metals have been found to be highly toxic especially when their natural concentrations are exceeded. At normal concentration, they promote the functions of the enzymes but could lead to a lot of adverse metabolic reaction when their concentration rises beyond tolerance limit. The untreated effluents contain a lot of pollutants that are harmful to human beings when they exceed the permissible limits. The Zemilli Paint Factory in Ethiopia produces maximum of 36,000 liters of paint per day and as a result it generates about 500 liters of liquid waste on average per day. This massive quantity of untreated effluent is disposed to the river side and cause considerable load on the water courses leading to widespread damage to aquatic life and to the environment. The problem is more severe in Addis Ababa, where most (More than 40% of large and medium scale manufacturing industries are located. Addis Ababa, like most developing cities, lacks the infrastructure, financial resources, and institutional capacity necessary to effectively manage industrial wastes and adequately control industrial pollution [1]. Paint manufacturing sector in Addis Ababa localized in different part of the sub city, most of them were concentrated in the residential and commercial area such as Nifas silk lafto sub city and Akaki Kality sub city. However, some of them are found in regional state. They have no proper waste discharging mechanism and no modern treatment plant which can handle their effluents waste accordingly. Materials and Methods Study areaThis study was employ on the city of Addis Ababa. Addis Ababa AbstractPaint industry is one of the industries that cause the water pollution by generating Wastewater primarily due to cleaning operations of mixers, reactors, blenders, packing machines and floors. The present research work deals with the study of some of the important physico-chemical and heavy metal parameters of paint industrial waste water effluents which was aimed at the analysis of the untreated effluents from six paint factories in Addis Ababa and the surrounding area. Analysis physico-chemical and heavy metal parameters of selected paint factories samples in Kadisco (KA), Zemilli (ZE), Rainbow (RA), Gastor solar (GA), Nifas silk (NI) and Modern building industry (MBI) were performed to investigate the concentration of status of the parameter. In this study, like; physico-chemical and heavy metal parameters pH, EC, TDS, TSS, COD, Cd, Cr, Pb, and Zn of the nine wastewater samples were analyzed using, Dana multi-meter, Jenway Model 4510 Conductivity/Temp Meter (451 001), Gravimetric, Volumetric, Colorimetric, flame emission photometry, and Atomic Absorption spectrometry (AAS)analyses methods. In t...

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Among the variables that could influence the citizens' sense of a healthy environment, odor emissions play an important role, as they deeply affect the human life quality and psycho-physical wellness.