Desain Piringan Biologis Tetap

ABSTRAK Most of the river condition in Indonesia are lightly or heavily polluted. Data in /992 shows that 39 rivers in Indonesia are in critical condition. This condition calls for an effort to parity the water body funn pollution, as preventive approach is inhibitively possible due to weakness in law enforcement. One of the possible alternative to lessen the problem is to set up water purification system on the river body. Instead of absorb power from grid lines, the proposed .sysrem can be powered by the water flow itself or by solar sources. The focus of the study is to assess the effectiveness of the biological disc system to remove BOD. The characteristics of fixed biological disc used in this study consist of 5 discs, each is separated by I cm and of nominal size (nun): 50x100x200. Its specific surface area is 50 m2/m3 with void space of 207. Effectivity of BOD removal by biological disc depends on the fluid fihn thickness and passing frequency on the disc. BOD removal efficiency with fluid film thickness of 0.11 nun are 21% and 67% for Ix and 5x passes, with 0.13 nun are 9.6% and 39% for I x dan 5x passes, while with 0.16 nun are practically zero for Ix dan 5x passes. A 0.11 nun fluid film thickness require 2,2 rti'iday per m2 disc surface area and hydraulic retention time of about 3 hours. The process can be pets/armed in batch or continuously Keywords: Prokasih, pencemaran air sunga