The client, a coal red power plant located in a center-east state of India, had a requirement of a water treatment system to recycle the plant’s cooling tower blowdown water containing high colloidal silica and turbidity. Ultrafi ltration was selected as the pretreatment of choice to the Reverse Osmosis (RO) plant. UF was required in the tertiary treatment to provide consistent product water with low silt density index (SDI) to safeguard the downstream RO unit from colloidal fouling.
The OEM chose QUA’s Q-SEP® hollow fiber UF membranes as the ultrafiltration solution for the project due to the higher design ˛flux rate. With a higher ˛flux rate of 65 l/m2/h, QUA was able to offer lesser number of modules compared to other manufacturers, saving on capex for the client.
QUA provided exceptional pre-sales engineering support to the integrated system supplier in designing the UF system, which ensured efficient and successful installation at site and subsequent commissioning and performance. Q-SEP modules successfully met the plant’s requirements because of their low fouling charac-teristics, uniform pore size distribution and large surface area which provided high operating efficiency and reliable operation.
The Q-SEP system comprises of two trains of 28 modules each. The system is designed to operate in the dead-end mode.
The UF system has been operational since February 2018. It has been performing uninterrupted and satisfactorily and is able to provide a consistent permeate output of 100m˜/hr in each train. The Trans-membrane pressure (TMP) has been consistently below 1 bar. Chemical Enhanced Backwash (CEB) is done once a day. The output SDI is consistently below 3 since startup.
The client has gone on record to recognize Q-SEP performance and has issued a performance certificate to that effect.
UF Permeate Water Parameters
Feed Flow: 110 m˜/hr/stream
Net Product Flow: 100m˜/hr/stream TMP: 0.4 kg/cmˇ
Product water turbidity: 0.1-0.2 NTU Product water SDI˘ : <3