(249c) Response Surface Optimization for the Development of a Compact, Rapid, and Zero Liquid Discharge Wastewater Treatment System

Developed countries most commonly employ activated sludge treatment plants or utilize aerobic digestion in another manner to reduce solid content in municipal wastewater. These types of centralized treatment facilities are not feasible to construct or maintain in many places, and demand for new water conservation solutions is also growing globally. Zero-liquid discharge wastewater treatment, in which direct flocculation is the primary treatment step for solid-liquid separation, could serve as a rapid, compact, and highly efficient system for treating municipal wastewater in locations where abundant freshwater and skilled operating personnel is not available.

In this work, the direct flocculation process was used with a cationic polymer to flocculate raw municipal wastewater and the effects of manipulating process conditions were examined. A 5 level, 4 factor central composite design of experiments was performed to analyze and model the response of TSS and COD reduction as a function of flocculant dose, mixing time, mixing speed, and polymer solution concentration by applying response surface methodology. Direct flocculation proved to be an efficient and rapid method for inducing the settling of solids in raw wastewater.