Abstract:
Cengar natural clay has been used as a raw material for the synthesis of liquid coagulant
and adsorbent. Calcining clay at a temperature of 700 °C for 3 hours and leaching of
100 °C for 2 hours using an extractor 0.4 mol H2SO4 produced filtrate as a liquid
coagulant and residual clay as an adsorbent. Coagulation was done by contacting the
Siak River water sample and coagulant. Resulted coagulation of Siak River water was
adsorbed by adsorbent which was side product of the synthesis liquid coagulant
weighing 2 g with a variation of the contact time of 2, 8, 12 and 24 hours. The
coagulation result showed the decrease percentage in color, turbidity and organic matter
content of each were 71.3%; 79.7%; and 49.8% with an increase in pH from 6.1 to 6.6.
Parameters of color and content of organic substances resulted from coagulation did not
meet with PERMENKES No. 416 / MENKES / PER / IX / 1990 "About the Terms and
Water Quality Monitoring". Adsorption of the Siak River water after coagulation with a
contact time of 12 hours (RLC(2-12)) had the highest percentage reduction in the color of
84.9%; turbidity of 87.8%; organic substances of 44.4% and an increase in the pH from
6.6 to neutral. Three parameters (pH, color and turbidity) Siak River water already meet
with the PERMENKES, except the content of organic substances
