Open AccessPerformance intensification of the coagulation process in drinking water treatment
Author(s) -
Henry H. Mungondori,
Tariro Annah Muchingami,
Raymond Taziwa,
Nhamo Chaukura
Publication year - 2021
Publication title -
water s.a./water sa
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.389
H-Index - 59
eISSN - 1816-7950
pISSN - 0378-4738
DOI - 10.17159/wsa/2021.v47.i2.10911
Subject(s) - turbidity , raw water , chloride , water treatment , coagulation , chemistry , pulp and paper industry , aluminium sulfate , ferric , population , water quality , environmental engineering , moringa , environmental science , flocculation , inorganic chemistry , psychology , ecology , oceanography , demography , food science , organic chemistry , psychiatry , sociology , engineering , biology , geology
Surface water pollution has increased, owing to industrial development and population growth. Consequently, it is important to find alternative drinking water treatment strategies, which cater for changes in the quality of raw water. This study compared the efficiency of different coagulants in treating raw water that feeds a drinking water treatment plant (WTP). Using jar testing equipment and a number of physicochemical parameters, an investigation was conducted to establish optimum conditions for aluminium chloride (A), ferric chloride (B), and chitosan (C), and their performance compared with aluminium sulphate (D), which is the coagulant used at the WTP. The turbidity removal efficiencies for the single coagulants were in the order: B (95.7%) > A (94.7%) > C (94.4%), at optimum coagulant doses of 60, 50, and 0.6 mg/L, respectively. The coagulants achieved high removal efficiencies for turbidity, total dissolved solids (TDS), ultraviolet absorbance at 254 nm (UV254) and conductivity under acidic conditions. For dual coagulants, there was a gradual increase in the removal efficiencies of the tested parameters with increasing pH. Combined coagulants were more effective compared to single coagulants, with highest removal efficiencies being exhibited by the A/C combination. Overall, the coagulants proved to be suitable alternatives to D, since they had comparable performances.