OPTIMIZING AND EVALUATING THE EFFECTIVENESS OF VIBRATORY SHEAR ENHANCED PROCESS FOR THE SUSTAINABLE MANGEMENT OF COOLING WATER BLOWDOWN

Abstract

In this work, the implementation of vibratory shear enhanced process (VSEP) as an emerging membrane technology for the treatment of cooling water blowdown (CWBD) was investigated. VSEP offer the advantage of reducing the fouling problem associated with the membrane and give a higher flux over conventional membrane technologies. For this purpose, at the lab scale, the performance of six membranes made of different compositions were tested for best treatment, including four for reverse osmosis (ACM, ORM-31K, ULP, AG) and two for nanofiltration (DK and HFT-150). A membrane selection study was conducted to decide upon the most suitable membrane based on major parameters such as the permeate rate stability and its quality. Additionally, a pressure study was performed to choose the optimum pressure and use it for the concentration study to know the recovery percentage, then conduct a vibration and fouling studies. Key parameter such as pressure, flowrate, pump speed, and vibration speed were monitored or controlled to reach the desired permeate quality. The findings of the study showed that membrane ORM-31K gives a good balance between TDS removal of 99% and permeate flux of 75 L.m-2.hr-1 at a lower pressure of 380 psi compared to other membranes. The removal of dissolved ions like sodium, calcium, magnesium, chloride, sulfate, and nitrate were between 81% and 99%, and 92 and 99% for ULP and ORM-31K, respectively. Furthermore, increasing the vibration frequency from 0 to 43 Hz helped in increasing the permeate flux by 45.3% and 57.1% for ACM- RO and HFT-150-NF, respectively. The cleaning study on ORM-31K, helped in recovering the 75% of the initial flux at an optimum pressure of 380 psi. Finally, according to the permeate quality it is suggested that this effluent can be used in many applications. Mainly, reusing it back in the district cooling facility as a make-up water or it can be discharged safely to surface water without any damage to marine creatures.