The Separation Method for Removing of Colloidal Particles from Raw Water

The objective of this study was to develop a treatment system that can effectively reduce the concentration of colloidal particles in raw water that can greatly reduce the cost of treatment and improve the subsequent steps of treatment. Aluminum sulphate (alum) and ferric chloride as a coagulant and anionic polymer as coagulant aid were used in the process that changed the scale of particles from nanoscale to microscale and larger by a physico-chemical process. The influence of PH, temperature, coagulant and coagulant aid dosages on the coagulation process was studied and conditions were optimized corresponding to the best removal of organic matters, viruses, colloids, bacteria, color and decrease in turbidity. 85-98% reduction of turbidity from raw water can be achieved by using the optimum coagulant dosage (8ppm, ferric chloride/10 ppm, alum) in the optimum PH range (9.2, ferric chloride/8.5, alum) in the optimum temperature (20°C, ferric chloride/24°C, alum). Ferric chloride produced better results than alum. Higher dosages did not significantly increase pollutant removal and were not economical. The results provide useful information for raw water treatment.

[1]  Bruce Jefferson,et al.  Floc structural characteristics using conventional coagulation for a high doc, low alkalinity surface water source. , 2006, Water research.

[2]  S. Wong,et al.  Treatment of pulp and paper mill wastewater by polyacrylamide (PAM) in polymer induced flocculation. , 2006, Journal of hazardous materials.

[3]  P. Pavasant,et al.  Reduction of organic matter and trihalomethane formation potential in reclaimed water from treated industrial estate wastewater by coagulation. , 2005, Journal of hazardous materials.

[4]  Christelle Turchiuli,et al.  Influence of structural properties of alum and ferric flocs on sludge dewaterability , 2004 .

[5]  C. J. Williams,et al.  Treatment of tannery wastewater by chemical coagulation , 2004 .

[6]  P. L. Sibrell,et al.  Evaluation of chemical coagulation-flocculation aids for the removal of suspended solids and phosphorus from intensive recirculating aquaculture effluent discharge , 2003 .

[7]  M. Sorour,et al.  Pretreatment of agricultural drainage water (ADW) for large-scale desalination , 2003 .

[8]  N. Graham,et al.  Coagulation of humic acid by aluminium sulphate in saline water conditions , 2002 .

[9]  M. Franceschi,et al.  Optimisation of the coagulation-flocculation process of raw water by optimal design method. , 2002, Water research.

[10]  C. Driscoll,et al.  Survey of Residual Aluminum in Filtered Water , 1988 .

[11]  Philip C. Singer,et al.  Chlorination and Coagulation of Humic and Fulvic Acids , 1979 .

[12]  I. Arvanitoyannis,et al.  Influence of pH on adsorption of dye-containing effluents with different bentonites , 1989 .