| dc.description.abstract | The river water pollution prevails in
many parts of Indonesian region, due to the industrial,
commercial, residential and farming activities. In
many areas the quality standard of raw water has even
been violated. This leads to the increased water
treatment costs as well as public health risks. The use
of biofiltration system can be an effective means to
overcome these problems. The technology is able to
eliminate various types of raw water contaminants and
therefore reduces overall treatment costs. This paper
demonstrates the technical and financial benefits of
applying this technology as a pre-treatment step prior
to conventional coagulation and flocculation
processes. The experiments showed that bioreactor
filled with "honeycomb" type matrix can reduce COD
levels from 122-173 to 42-92 mg/L depending on the
hydraulic retention time applied, while that filled with
quartz sand can reduce COD levels from 128 to 32-43
mg/L. The biofiltration ,systems also demonstrated the
ability to reduce TSS from 56 to 5 mg/L or equivalent
to 90% reduction in the case of quartz sand matrix,
while honeycomb-type matrix showed slightly inferior
performance. The decrease in TSS will reduce
coagulant consumption in the subsequent water
treatment processes. It was also observed that
nitrification also took place in the biofiltration system,
indicated by removal of 55-75% ammonium
concentration. This will eventually reduce chlorine
required for disinfection. Based on these results, an
estimation of potential cost saving from the use of the
biofiltration process is derived. | id |
