Studies On The Treatment Of Coal And Brewery Wastewater Using Adsorption And Coagulation– Flocculation Techniques

CHAPTER ONE

1.0 INTRODUCTION

1.1 BACKGROUND TO THE STUDY

Materials play a major role also in lowering pollution and contamination of the environment. For this reason there are intensive research activities in the areas of lowering toxicity of exhausts, confinement of contamination and recycling of materials of many kinds- including water. Effluent disposal is a major problem around the world. Growing along with the population growth, industries create environmental problems and health hazard for the population. Hence, environmental concerns and progressive depletion of raw material resources behoove scientists and engineers to develop materials from renewable agricultural and plant resources to lower the extent of pollution of the environment (Brostow, Hagg Labland, 2009). The world population is increasing- while availability of potable water is decreasing. Water is essential for the survival of human beings- not to mention modern industry. Although the earth consists of 75% of water, xii water for drinking, sanitation, agricultural and industrial processes is not easily available. According to the United Nationals Organization Report of 2005, 1.2 billion people lack access to adequate amount of clean water and 2.6 billion people lack proper sanitation. This situation got only worse since 2005 and necessitates recycling of municipal wastewater and industrial effluent on a massive scale. To meet the requirements of potable, industrial and agricultural water, we have to treat the wastewater, particularly the municipal sewage, sludge and slimes and industrial effluents. Water is used among other applications, in mineral processing, such as in bringing metal ores in the form of water slurries from their original location below the Earth surface to the surface and also in subsequent transport. Movement of coal from its deposits in coal mines and the subsequent surface transport similarly requires the use of water. In the brewery industries, water is also necessary for production. It is for such reasons that the problem of potable water is related to that of industrial water. Clearly less use of industrial water- or recycling some of it- will increase the supply of potable water. The effluents are highly undesirable and unsafe to use. Wastewater contains solid particles with a wide variety of shapes, sizes densities and composition. Specific properties of these particles affect their behaviour in xiii liquid phases- and thus the removal capabilities. Many chemical and microbiological contaminants found in wastewater are coagulated and adsorbed on or incorporated in the solid particles. Thus, essential for purification and recycling of both wastewater and industrial effluents is the removal of solid particles. In this work, attempt is made to use adsorption and coagulation/flocculation as tools to investigate the aggregation process while varying the dosage of adsorbent and varying the dosage, pH and type of coagulants on coal and brewery effluent samples.

1.2 AIMS AND OBJECTIVES This research study shall achieve the following objectives:

1)The characterization of brewery and coal effluent samples.
2)The determination of the adsorptive behaviour of the effluents using one locally sourced adsorbents.
3) Adsorption isotherm testing, kinetics models, temperature dependency and thermodynamic parameters using coal and brewery effluents.
4) Effects of process parameters on the coagulation/ flocculation of brewery effluent sample.
5) Determination of the rate of coagulation and the constants of coagulation using brewery effluent sample.

1.3 SIGNIFICANCE OF THE WORK

Wastewater discharged to the environment may contain toxic compounds, heavy metals that are harmful. It can cause a lot of health issues to human and aquatic life. An effort to ensure adequately treated effluent that conform with WHO standard makes this work very important. Information available from this study will assist in the improvement of wastewater treatment and reduce waste of water resources and cost on the environment.

1.4 SCOPE OF THE RESEARCH WORK.

1) Batch adsorption experiment using one natural adsorbent.
2) Effect of the adsorbent concentration on the adsorptive removal of TSP (total suspended particles) and the amount adsorbed.
3) Evaluation of equilibrium isotherms and correlation coefficient value (R) .
4) Coagulation experiment comparing two coagulants. 5) The evaluation of coagulation constant, coagulation rate(-rA) and the order of reaction ().