Development of coagulant synthesis byproducts from cengar clay as adsorbent in post-coagulation peat water treatment

Abstract

Cengar clay was used as a precursor for liquid coagulant and adsorbent. It was calcined at 700°C for 1 hour followed by extracting with 0.2 moles H2SO4 at 80 and 100°C for 2 hours respectively. The main products are liquid coagulant of LC1(80-2) and LC1(100-2) which applied to coagulate the peat water. The liquid coagulants were characterized for pH and cation contents. And then after coagulation, peat water were adsorbed by using each extraction byproducts of liquid coagulant include LCA1(80-2) and LCA1(100-2) having adsorbent-peat water ratio 0.5:100 and 1:100 (w/v). Minerals characteristic of adsorbents were characterized using X-ray diffraction method. The several peat water parameters were analyzed for pH, color, turbidity, and organic substances. The results achieved that liquid coagulants were containing bivalent cation (Ca and Mg) far more than trivalent cation (Al and Fe) and pH 7-8. On the other hand, the adsorbent has found of kaolinite, montmorillonite, muscovite and calcite minerals. The liquid coagulant has not been able to improve the overall parameters analyzed. However, the LC1(80-2) coagulant achieved only removal efficiency of color 12.47%, turbidity 17.59% and organic substances 2.55% respectively. Meanwhile, the most effective adsorbent for post-coagulation peat water was achieved by LCA1(80-2) on 1:100 ratio that increases the water pH becomes neutral, removal efficiency of color 96.57%, turbidity 98.03% and organic substances 81.55%, respectively. Therefore, the adsorbent performance is much better than the coagulant in peat water treatment. As a conclusion, the adsorption step can cope up with the bad condition of post-coagulation of peat water.