STUDI PENURUNAN TSS, TURBIDITY DAN COD DENGAN MENGGUNAKAN KITOSAN DARI LIMBAH CANGKANG KEONG SAWAH (Pila ampullacea) SEBAGAI BIOKOAGULAN DALAM PENGOLAHAN LIMBAH CAIR PT. SIDO MUNCUL, TBK SEMARANG.

PT . Sido Muncul, Tbk is one of the largest and well-known herbal industry in Indonesia. PT . Sido Muncul,Tbk produces wastewater that contains high concentration of solids (TS) largely in the form of organic materials that cause high turbidity. The characteristics of the wastewater in the equalization basin was BOD 913.29 mg/l ; COD 6250 mg/l ; pH 5:33 ; Temperature 27 o C ; 651 NTU turbidity and TSS 780 mg/l . Research had been conducted with batch method to treat PT . Sido Muncul, Tbk’s wastewater by adding chitosan extracted from rice fields conch shell (Pila ampullacea) as an alternative eco friendly bio-coagulant. Chitosan extraction results have a degree of de-acetylation , ash content and moisture content of 36.9 % ; 6.72 % ; 36.29 % respectively . The application of chitosan as bio-coagulant in herbal  industry’s wastewater treatment (PT . Sido Muncul, Tbk) was done by adding variation of doses of 150 mg/l ; 200 mg/l ; 250 mg/l and 300 mg/l and variation of stirring speed of 100 rpm ; 125 rpm and 150 rpm . The results showed that chitosan extracted from rice field conch shell was able to reduce the solids contained in the wastewater with the optimum dose of 250 mg/l at 100 rpm stirring speed. Decreased levels of the parameters studied were TSS 84.84 %, turbidity 73.76 % and COD 68.86 %.