Abstract:
Using hydrocyclone in series and hydrocyclone equipped with grit pot in series as a pre-treatment unit in drinking water treatment process at Samlae pumping station Prathumthani, were studied in term of suspended solid separation efficiency and effect of operating parameters such as inlet pressure, diameter of hydrocyclone and grit pot operating time. The results were compared with single hydrocyclone from other research. The result showed that hydrocyclone in series had a very high flow split (Rf). So it is not possible for applying in the real operation. While the hydrocyclone equipped with grit pot in series showed, in term of solid separation efficiency, slightly low efficiency as 30.89%, which is nearly the same value as a single hydrocyclone. Moreover, the results showed that it can separate most large size of solid. This hydrocyclone also showed a high solid concentration, average 2,158 mg/L. Moreover, this research found that the highest efficiency of hydrocyclone equipped with grit pot in series was hydrocyclone diameter 50 and 10 mm. And, using hydrocyclone diameter 50 mm can prevent in hydrocyclone 10 mm from clogging problem. In term of expense, calculated from the data at Samsaen water treatment plant, this unit can reduce total quantity of sludge and alum usage. The amount of sludge decreased was 5.85 ton/day which can reduce the expense of sludge treatment 55,614 baht/day. So, hydrocyclone equipped with grit pot in series is a good choice for using as a pre-treatment unit in drinking water treatment process due to its compactness. In addition, it can also decrease the amount of coagulant usage and chemical sludge which is very hard to dispose.