pH and Particle Structure Effects on Silica
نویسندگان
چکیده
Coagulation is presented as an efficient alternative to reduce the silica content in 14 effluents from recovered-paper mills that are intended to be recycled by a final reverse15 osmosis (RO) step. Coagulation pretreatment by several polyaluminum chlorides 16 (PACls) or FeCl3 was optimized prior to the RO process. PACls with low alumina 17 content and high basicity achieved almost a 100% removal of silica at pH 10.5. A good 18 reduction of the silica content was attained without regulating the pH by adding one of 19 these PACls. Silica removal was related to the structure of the produced clots in which 20 cylindrical particles produced higher silica removal. All coagulants removed more than 21 50% of the chemical oxygen demand (COD). 22
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