The Effect of Both, Bed Filter Thickness and Kinds Trickling Filter Media on Various of Flowrates to Decrease of Tapioca Wastewater

Abstract

Tapioca industry growth rapidly, so wastewater from its increase too.  The quantityof wastewater from tapioca industry is large and they have high BOD (Biological OxygenDemand) and high COD too (Chemical Oxygen Demand), so if they are untreated beforerelease to streams, include to high pollutant stage. Organic matter content on wastewater decreased by biological treatment,  one ofthem is trickling filter.  Trickling filter basically is an artificial channel, consist of roughand uncertain shape materials as a filter arranged in the channel.  Wastewater spray onit and flow in this channel trickle down through this filter has the form of thin layer abovesurface of filter media, which have contact with air.  Biological slime consist bacteria,protozoa and other microorganism living on surface of filter media, consume organicmatter of wastewater, so they are decrease.   The experiment was aimed at studying the effect of flowrates and filter bad thicknessof trickling filter process with river rock and plastic ball as filter media to efficiency BODdecrease of tapioca wastewater.  The experiment is conducted using randomized block design, employing two factorsi.e. a bed filter thickness (T) and a type of filter media (M).  The filters consist of threerespective levels; 1m, 1.5m, and 2m and the media employed are river stones and plasticballs, respectively.  The respective applied are 35 ml/min, 105 ml/min and 175 ml/min. The treatments are conducted in three replicates. The results showed that the use of 2 m bed filter of river stone at flowrate of 35ml/min reduced BOD level by 5263 ppm, which is equivalent to 75.18 % of its initial level. However, the use of 1 m bed filter of river stone at a flowrate of 175 ml/min resulted inthe lowest reduction of BOD level i.e. 2672 ppm.

Keyword: trickling  filter, tapioca industry, and tapioca wastewater