Recycling of Sewage Sludge to Prepare an Effective Adsorbent to Treat Selected Heavy Metals- Contaminated Water

Document Type : Original Article

Authors

1 MSC student, Department of Environmental Engineering, College of Engineering, Mustansiriyah University, Baghdad, Iraq

2 Professor, Dr., Department of Environmental Engineering, College of Engineering, Mustansiriyah University, Baghdad, Iraq

Abstract

TThe introduction of more stringent legislation limiting the disposal and use of sewage sludge, combined with an increase in its production and the loss of previously recognized disposal routes, has sparked a search for alternate applications for sewage sludge. The conversion of sludge into adsorbents is one of the promising technologies give a more stable treatment of sludge. In a batch mode adsorption, adsorbent created by recycling sewage sludge was employed as a sustainable and low-cost material to remove iron and copper ions from simulated polluted aqueous solutions. A laboratory test was done to determine the influence of a variety of operational parameters on metals adsorption, including the acidic function (pH), agitation speed, adsorbent dosage, agitation period, and initial concentration at room temperature. The maximum removal efficiency was 98.91 and 98.22 % for Fe and Cu respectively at optimum factors: pH=4, agitation time =250 rpm, agitation time=180 min, adsorbent dose=1.5 g and initial concentration=50 (mg/l) for each metal .The isotherm system was studied using the three most popular models, Freundlich, Langmuir, and Temkin models. The results of the isotherm models showed the Langmuir model isotherm gave an obvious preference with the high correlation coefficient R2=0.933 for Fe and R2= 0.927 for Cu. In this way sewage sludge, which pollutes the environment and is costly to treat, may be recycled in a useful and economic way to achieve the lowest heavy metals concentration level.

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