Drawer Compacted Sand Filter: A new and innovative design for on-site wastewater treatment

In this paper, results of new intermittent sand filter design was presented. Drawer Compacted Sand Filter DCSF is a modified design for sand filter, in which sand layer is broken down into several layers (10 cm each) and placed in a movable drawers separated by 5 cm space each. Lab-scale DCSF was designed and operated in Surrey University's lab for 49 days and fed by synthetic greywater. 30 cm of sand media was placed in three drawers, 10 cm each. 8 cm gravel was placed in the first drawer at the top of the chest. The effective size of sand media and gravel were 0.2 mm, 3 mm, respectively. The organic load was 42780 mg/m 2 .day and hydraulic load was 50L/m 2 .day. Significant reduction in BOD5 and TSS was noticed between drawers 1 and 2, whereas no significant reduction was observed by passing water through all drawers. The study concluded that accommodating sand media in movable drawers and distribute hydraulic load between drawers would minimize the maintenance and space requirements for sand filter. However, this research is a preliminary study and further investigation is currently being done to optimize the system.