Gas Extraction from Sludge as Acquired from Oxidation Ponds of Community Wastewater and Cassava-Factory Wastewater Treatment through Nature-by-Nature Processes

The study was aimed on determining the gas volume from sludge of oxidation ponds for community wastewater treatment and UASB tank of cassava factory for wastewater treatment in which the organic matters of both units were digested through the nature-by-nature process. The amounts of oven- dry weight sludge about 200 g were collected in the light brow glass bottle with 2.5-l capacity. The fermentation of organic matters in sludge is the process to produce gases and being transferred to store in chamber by fluid displacement. The gases from sludge of oxidation pond was occurred on the second day and the maximum on the sixth day with the rate of 70 ml/d and average of 36.02 ml/d (total 360.23 ml for 10 days) while cassava factory sludge found the maximum volume on the first day with the rate of 142.6 ml/d and average of 72.2 ml/d (total 649.97 ml for 9 days). In other words, the oxidation pond sludge can produce gas 1.8 ml/g (oven dry weight) while the cassava factory sludge found gas 3.25 ml/g (oven dry weight). Research results found gases of oxidation pond sludge on the range of methane concentration between 545,686 – 9,560,606 ppm, hydrogen sulfide 55.94 to 360.27 ppm, and ammonia ND to 36.22 ppm, while the cassava factory sludge found methane gas concentration between 729,404 to 9,900,837 ppm, hydrogen sulfide 5,894 to 68,050 ppm, and ammonia ND to 44.15 ppm.