As part of compliance requirements, a new pharmaceutical assay production facility in Shanghai, China, owned and operated by a major multinational pharmaceutical company, was required to implement a zero liquid discharge (ZLD) wastewater treatment system. The ZLD system incorporates high-pressure reverse osmosis (RO) with permeate RO polishing and an evaporator for brine concentration. With a large installed base globally, the high-pressure RO step was designed around spacer tube RO (STRO). The STRO has a proven track record of handling elevated organics, highly scaling feed, and high pressure in high recovery operations, all of which are present in this wastewater. While the Shanghai plant was under construction, it was decided to run a pilot trial at a similar pharmaceutical facility inside the corporation family, located in Massachusetts, United States. The pilot trial was run using disc tube RO (DTRO), which is a good representation of the STRO except that the DTRO has a more open feed flow path, requiring reduced pretreatment, allowing for simpler pilot trials. The feed wastewater presented high variability, with pH ranging from 8 to 10.5 and TDS from 1,000 ppm to 4,000 ppm, COD averaged 400 mg/l with peaks up to 2,900 mg/l, BOD average of approximately 200 mg/l. The operating pressures were between 900 psi and 1,320 psi. The permeate COD was approximately 25 mg/l, and the permeate TDS was always below 200 mg/l. Additionally, the pilot required antiscalant and pH control via acid addition to avoid scaling due to a high content of phosphates in the feed. Significant biofouling was experienced on the cartridge filter system, and a regime of biocide dosing as part of commercial system pretreatment was recommended. The pilot ran for ten weeks, and it achieved the objectives for removing LAS surfactants, Total Phosphorous, and SVOA surrogates. The pilot ran 95% recovery for different fluxes, finally recommending 5.6 GFD design flux. The STRO cleaning regime was refined during piloting as well, thereby confirming all key design parameters for the commercial system. The commercial system is currently under construction and will be operational by 2022.
This presentation is available to AMTA Members only.
- Julian Arroyo
- Crosstek Membrane Technology LLC
- AMTA/AWWA Membrane Technology Conference, Las Vegas
- AMTA/AWWA Membrane Technology Conference
- High-Pressure RO, ZLD, Wastewater