Water & Wastewater Asia Mar/Apr 2018

WATER & WASTEWATER ASIA March / April 2018 FROM THE GROUND / 27 only capture less than one per cent of the total population present. By measuring ATP regularly, and differentiating between cellular ATP inside active microorganisms and dissolved ATP released from dead cells, the cause & effect relationships can be identified to resolve microbiological challenges before it’s too late. ASRP Testing Current microbial monitoring consists of regulatory culture- based testing of produced water for coliforms and E.coli. Results, however, are only available two to five days from sample collection so ATP was investigated as a rap i d me thod for assess i ng microbiological contamination. A site audit was completed by Arthur Kokolekos of LuminUltra along with Kevin He and Shanli Zhang of City West Water. Six sample points were selected across the ASRP plant to test ATP levels with the QuenchGone Aqueous (QGA) test method: the feedwater tank (SP6), UF outlet (SP5), cartridge filter inlets (SP4), RO1 inlet (SP3), RO1 permeate (SP2), and final produced water (SP1). Because plant feedwater is received from the AWTP, it is critical that elevated microbiological growth levels are detected quickly and treated effectively to ensure consumer safety and to maintain infrastructure and equipment integrity. The results The QGA test kit and equipment set were taken into the field and tests were completed at each of the six sample points. Control ranges were set to the recommended guidelines for “water for consumption”, which includes potable and sanitary water. Results were returned within f i ve mi nut es of t es t i ng and effective removal of microbiological contamination was seen at each stage of the process — the most significant decrease was through the ultrafiltration system and the first pass RO system. Continuous monitoring allows operators to identify microbiological growth at the earliest stages, which then assists in identifying biological foulingwithin themembrane filtration systems. This provides them with information required for optimal cleaning frequencies; appropriate treatment to prolong the lifespan of their membranes, equipment and infrastructure; and to confirm biological control throughout the system. B e c a u s e a v a r i e t y o f microorganisms can result in water quality issues and infrastructure risks, an immediate measure of total microorganisms is an invaluable first line of defence in the management of water treatment systems. When elevated risk is identified, further action can be taken and efficacy of the corrective action can be confirmed immediately to ensure consistent high quality produced water. Just like this, LuminUltra’s rapid microbiological monitoring technology has created amonitoring programme that can be easily established for any water system, no matter the size. WWA The results ASRP System ATP Audit 1000 100 10 1 0.1 pg cATP/mL Feedwater tank UF Outlet Cartridge Filter Inlet RO1 Inlet RO1 Permeate Produced Water