Editor-in-Chief Elisabeth Lisican showcases a handful of features to read in the April 2017 issue of Water & Wastes Digest.
Biwater awarded contract for ultrafiltration, reverse osmosis systems
Biwater Inc. has been awarded a contract to design, supply, and supervise the installation and commissioning of ultrafiltration (UF) and reverse osmosis (RO) systems for the Groundwater Reliability Improvement Program (GRIP) advanced water treatment facility under construction in Pico Rivera, Calif.
The new 14.8 million gpd (56 million liter per day) plant will support the Water Replenishment District (WRD) of Southern California in its aim to be 100% independent from imported water. Site work is underway to meet a completion date of July 2018.
“The membrane systems are two of the three key process technologies essential to the indirect potable reuse solution. Biwater’s membrane technologies will help replenish groundwater supplies to ensure local aquifers are sustainable and continue to be a vital and growing contributor to the region’s water demands,” said Jorg Menningmann, president of Biwater’s Membrane Treatment and Desalination Sector.
The source water for the new GRIP facility is tertiary effluent from two wastewater treatment plants. The 10-train UF process will remove particulates and organisms prior to the RO membranes, thereby contributing to stable RO operation and performance. To enhance overall system recovery rates, backwash waste from the primary UF system will be processed by a subsequent secondary recovery UF system. Overall recovery for the UF system will be 99.7%.
Thereafter, the UF filtrate will be treated by four primary RO trains (2 stage) followed by four concentrator RO trains (1 stage) running at a product recovery rate of 92.7%. The RO membranes will remove/reduce ionised salts and dissolved organics such as metals, nitrates and total organic content (TOC).
The combined RO product will then be sent through a chemical oxidation/ultraviolet (UV) reactor advanced oxidation process, which will breakdown low molecular weight compounds in the category of Contaminants of Emerging Concern (CECs).
The system operations will be optimized prior to start-up with data gathered from pilot plant operations that will run concurrently with the initial design phases of the project. This data will be instrumental for tuning in chemical feed rates and membrane cleaning frequency and techniques. As the raw water source is unique and variable with two different sources, the pilot plant data will be invaluable and allow initial operations to begin with optimum conditions. Biwater’s ultimate goal for the pilot plant is to fine tune the operations to reduce energy and chemical consumption and extend useful membrane life.