Ultrafiltration (UF) is commonly used as a pre-treatment to Reverse Osmosis (RO) to ensure reliable, consistent and efficient operation.
As Shandong Hongxin Chemicals Co., Ltd in China recently discovered, this consistency and reliability, along with enabling quick setup and installation times, helped them realise convenience and cost savings. Additionally, given the fluctuations in contamination levels of the water source, the selected UF modules continuously exceeded requirements.
In 2014 HWTT designed a 13,000 m3/day ultrafiltration system that was equipped with 120 Liqui-Flux® W10 modules to provide reliable pre-treatment to RO. The water source for this project was the middle and lower reach of the Yellow River.
The system design consisted of a settling pool to lower Total Suspended Solids (TSS), such as sludge and sand from the river. Due to the presence of algae and other organic contaminants, the feed water to the UF is continuously conditioned with 2 ppm NaClO which improved the filtration process. Finally, 100 μm disc filters are used to protect the UF capillary membrane from obstruction by large particles.
The reliable and robust design of the Liqui-Flux® W10 UF modules allowed HWTT to install, preserve and ship the entire skid after testing was completed. This allowed the customer to shorten installation time by several weeks and save on construction and testing costs. A heat exchanger is used to maintain a certain minimum of water temperature in winter times.
This UF system has been running since March 2014 without incident. The produced water continues to exceed the customer’s technical requirements with SDI ≤ 3 and turbidity < 0.2 NTU. The recovery yield exceeds the 90% and low maintenance and service level also proved to be above expectations.