Optimization of progressive freeze concentration on stormwater purification via response surface methodology

Shortages and lack of sources of clean water is a big issue nowadays. This problem happens because of the increment of population that leads to the amount of water usage increases at an alarming rate. Therefore, the sources of water must be explored in order to get a continuous supply of clean water. This paper recommends a new approach to get clean water, which is by purifying the stormwater via progressive freeze concentration (PFC). This method produces a single ice crystal block that contains high purity of water. This paper focuses on the optimization of two operating parameters, which are coolant temperature and operating time. In order to determine the effectiveness of this technology, effective partition constant (K) and concentration efficiency (Eff) were examined. Response surface methodology and central composite design were implemented to find the optimum operating conditions via Statistica software. The best responses for K and Eff obtained were 0.189 and 81.0%, respectively, with the optimum condition at coolant temperature of -8.9 degrees C and operating time at 41.1 min. From the findings, it is proved that PFC has the capability to reduce the concentration of unwanted solute in stormwater and this process has a high potential to be an alternative approach to purify the stormwater.