Evaluation of Poly-Alumino-Iron Sulphate (PAFS) as a Coagulant for Water Treatment
This paper is concerned with the performance of a new kind of pre-polymerised inorganic coagulant, poly-alumino-iron sulphate (PAFS), for use in drinking water treatment. Considerable laboratory work has been undertaken to evaluate the performance of PAFS in comparison with conventional coagulants such as ferric sulphate (FS) and aluminium sulphate (AS), for the coagulation of a model upland coloured water and a typical lowland surface water in the UK. The results have shown that the PAFS coagulant was superior to the FS and AS in terms of the removal of colour, UV254-absorbing substances and dissolved organic carbon (DOC). PAFS achieved the lowest residual concentrations of Fe and Al in comparison with FS and AS, respectively. In addition, to achieve an equivalent removal percentage, a lower coagulant dose (in molar units) was required for PAFS in comparison with AS and FS.
KeywordsHydroxide Sludge Sedimentation Electrophoresis Turbidity
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