Abstract
A study was carried out in a specially designed settling column to investigate the settling characteristics of effluents arising from Karachi tanneries. The Jar-tests were conducted to determine the optimum dosage of coagulants such as potash alum and ferric chloride to maximize the removal of suspended solids (S.S) from the wastes. For alumn, the optimum dosage was found to be 150 mg L−1, whereas with ferric chloride it was 30 mg L−1. Experiments carried out in the settling column with the optimum coagulant dosages showed that the coagulation with ferric chloride was much better than with alumn, as it removes about 84% S.S from the wastes compared to 70% removal obtained in case of alumn. Design curves in terms of percent removal of S.S. vs loading rate and detention time were constructed using data obtained from settling column. These curves can be used in designing the settling tanks employed in the tannery wastes treatment plants.
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Supervisor of the project, correspondence to be addressed.
Post Graduate Student, presently employed as research Engineer in PCSIR Laboratories, Karachi.
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Akhtar, W., Rauf, M., Ali, I. et al. Optimum design of sedimentation tanks based on setting characteristics of Karachi tannery wastes. Water Air Soil Pollut 98, 199–211 (1997). https://doi.org/10.1007/BF02047034
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DOI: https://doi.org/10.1007/BF02047034