Biological removal of ammonia and manganese for Hong Kong
To meet the increasing demand for drinking water, the new Tai Po Water Treatment Works was built in Hong Kong. The plant has a production capacity of 1200 Ml/day
PABF with Filtralite® filter media strongly reduced the chlorine demand
Tai Po Drinking Water Treatment Plant takes its raw water from the river Dongjiang in the Guangdong Province north of Hong Kong. The inlet water has an average turbidity level of around 11 NTU and contains ammonia and manganese. Water temperatures range from 12 to 34oC.
While designing the waterworks, use of primary aerated biological filters (PABF) with Filtralite filter media was selected for removal of ammonia and manganese. This solution strongly reduced the chlorine demand for the plant compared to the alternative execution with break point chlorination.
Pilot tests where different media were compared showed that the expanded clay filter media Filtralite was the best solution for the PABFs.
The test column containing Filtralite HC (High density, Crushed aggregates) 2.5-5 mm had a stable ammonia removal of 80-90% and a manganese removal of 75%.
The plant has began operation in April 2003 and operating data shows that the PABFs work very well. Both ammonia and manganese is removed to levels below the specifications.