Analysis and optimization of coagulation and flocculation process

Abstract

Natural coagulants have been the focus of research of many investigators through the last decade owing to the problems caused by the chemical coagulants. Optimization of process parameters is vital for the effectiveness of coagulation process. In the present study optimization of parameters like pH, dose of coagulant and mixing speed were studied using natural coagulants sago and chitin in comparison with alum. Jar test apparatus was used to perform the coagulation. The results showed that the removal of turbidity was up to 99 % by both alum and chitin at lower doses of coagulant, i.e., 0.1-0.3 g/L, whereas sago has shown a reduction of 70-100 % at doses of 0.1 and 0.2 g/L. The optimum conditions observed for sago were 6 and 7 whereas chitin was stable at all pH ranges, lower coagulant doses, i.e., 0.1-0.3 g/L and mixing speed-rapid mixing at 100 rpm for 10 min and slow mixing 20 rpm for 20 min. Hence, it can be concluded that sago and chitin can be used for treating water even with large seasonal variation in turbidity.

Syntheses, Characterization and Applications of Graft Copolymers of Sago Starch – A Review

“…The dangling grafted chains on the polysaccharide backbone, due to increased flexibility, could easily approach the contaminants. Saritha et al showed that sago starch is very efficient in removal of color, turbidity, alkalinity, and hardness compared to alum …”

Effects of a polymeric organic coagulant for industrial mineral oil wastewater treatment using response surface methodology (RSM)

“…This is because polymeric organic coagulants are effective at a wide range of pH (Vedoy and Soares, 2015). Although the coagulant dosage was found to be the most influential factor, under-dose or overdose can hinder the objective of reducing the cost associated with chemical usage or improving water quality (Saritha et al, 2015). In this case, the pH and the flotation time were kept at constant optimum conditions of 5 and 15 min, respectively.…”

“…This occurred via the mechanism of flocculation of the oil droplets and the repulsion between the oil droplets and air bubbles (Saritha et al, 2015).…”

Physico‐Chemical Processes

“…In 2017, a few studies focused on some natural materials as treatment aids since they rarely need processes, and are less harmful than industrial chemicals. Saritha et al (2017) examined chitin and sago as coagulants for turbidity removal as compared with alum, which found that the natural coagulants had a better ability to deal with seasonal variance in turbidity than alum.…”