The optimized condition for reduction of activated sludge by sludge-lysing bacteria

For the purpose of reducing industrial waste, activated sludge, we isolated and identified three bacteria that can lyse activated sludge. The bacterium that was able to lyse sludge most effectively of three was named Brevibacillus sp. KH3. KH3 secreted sludge-lysing factor to sludge medium and sludge-lysing factor was probably certain specific protease when KH3 needed nutrient to grow. The optimized conditions for reduction of sludge by Brevibacillus sp. KH3 are at the temperature of 50 degrees C and in pH 8.0. The maximum sludge dissolution rate is about 25% under those reaction conditions after 4 days. The SS dissolution speed became faster in the initiate days while the Shaking speed gear up. The sludge dissolution rate got to 35% by concomitant 5% concentration of sludge medium. In order to improve the efficiency of sludge dissolution, a lot of supplements were added to sludge culture medium. The dissolution rate got up about 3% by adding with 0.5% Fe, got up about 3% by adding with 0.5% Na, and 6% by adding with 0.05% yeast extract. In addition, Brevibacillus sp. KH3 was immobilized on the loofa sponge that is a kind of nature immobilizing matrix, And the sludge dissolution rate got up 9% by immobilization.