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Abstract
Natural materials that are available in large quantities or certain waste from agricultural operations may have the potential to be used as low cost adsorbents, as they represent solid waste, widely available and are environmentally friendly after use it. The aim of this research is to evaluate the applicability of using one of these locally available materials (sawdust) to improve the sewage effluent quality.
The sawdust, low cost locally available material and solid waste, was tested as biosorbent for the removal of biochemical oxygen demand (BOD5) from effluent sewage. Adsorption of BOD5 onto this low-cost adsorbent was studied by continuous mode system. The effects of initial BOD5 concentration, flow rate, bed height, particle size, activated carbon/sawdust ratios and pH on adsorption capacity were studied. The experiments showed that the adsorption through the sawdust instead of commercial activated carbon was found to be very effective for the removal of BOD5, where the maximum removal percentage reached 86.23%.
1. Introduction
Fresh water is already a limiting resource in many parts of the world. In the next century, it will become even more limiting due to increased population, urbanization, and climate change, thus leading to water crisis and serious consequences on the environment. This limitation is caused not just by increased demand for water, but also by pollution in freshwater ecosystems. Iraq is one of the countries that is suffering from water crisis and is threatened by it more and more during the next years. Pollution decreases the supply of usable water and increases the cost of purifying it, however, liquid and solid wastes produced by human settlements and industrial activities pollute most of the watercourses throughout the world.
Wastewater is essentially the water supply of the community after it has been used in a variety of applications. From the standpoint of sources of generation, wastewater may be defined as a combination of the liquid (or water) carrying wastes removed from residences, institutions, and commercial and industrial establishments, together with such groundwater, surface water, and storm water as may be present (Metcalf and Eddy, 2003).
Untreated wastewater generally contains high levels of organic material, numerous pathogenic microorganisms, as well as nutrients and toxic compounds. It thus entails environmental and health hazards and, consequently, must immediately be conveyed away from its generation sources and treated appropriately before final disposal. The ultimate goal of wastewater management is the protection of the environment in a manner commensurate with public health and socio-economic concerns.
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- sewage, treatment
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