magnesium carbonate as a coagulant, recovery and reuse
نویسندگان
چکیده
in order to prevent water losses through disposing hydrous sludge during treatment of water, also recovery and reuse of chemicals; treatment by magnesium carbonate as a coagulant was examined in batch and continuous systems. 600 mg/1 mgco3 as optimum dosage reduced 80% turbidity of a highly turbid water containing 200 ntu. sulfates decreased, but hardness and alkalinity showed some increases. recarbonation by co2 resulted in recovery of 45% of magnesium carbonate which was used again as part of coagulants in continuous system. a mixture of magnesium carbonate and calcium oxide (lime) was examined. 600 mg/1 mgco3+250 mg/1 cao as optimum dosage showed 90% reduction in turbidity, 10% reduction in both hardness and alkalinity and almost 60% reduction in sulfates. recarbonation of sludge resulted in 73.5% recovery for magnesium carbonate and 40% for the lime, which were used again in a continuous system. six hours operation of a continuous system with a detention time of 1 hour confirmed results obtained from batch analysis. a third trial was experienced with a mixture of magnesium carbonate+sodium carbonate. although the total hardness showed more decreases, but the turbidity reduction was not satisfactory. as the conclusion, treatment of water by a mixture of mgco3+ cao is our choice. there will be no water losses in this method, resulting additional incomes by selling the 15-20% saved water and savings in expenditure and cost of coagulants. cost of new constructions and co2 production seems insignificant, comparing to savings and new income.
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Ehsan Noroozizadeh was born in Dezful/Khoozestan, Iran. He received his B.S. in Pure Chemistry (2011) and M.S. in Organic Chemistry (2013) from Bu-Ali Sina University, Iran. He is currently working towards his Ph.D. under the supervision of Professor Mohammad Ali Zolfigol. His research interest is catalysis, including the application of homogeneous and heterogeneous catalysis in organic synthesis.
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Ehsan Noroozizadeh was born in Dezful/Khoozestan, Iran. He received his B.S. in Pure Chemistry (2011) and M.S. in Organic Chemistry (2013) from Bu-Ali Sina University, Iran. He is currently working towards his Ph.D. under the supervision of Professor Mohammad Ali Zolfigol. His research interest is catalysis, including the application of homogeneous and heterogeneous catalysis in organic synthesis.
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عنوان ژورنال:
iranian journal of public healthجلد ۱۱، شماره ۱-۲، صفحات ۲۹-۴۶
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