News & Spotlights

Making the Case for PTFE Membranes

July 24, 2016

Pharmaceutical Plant in China
MBR System in operation since 2011
Treatment capacity: 1,900 m3/d (0.50 MGD)

In recent years, China has moved toward more stringent wastewater regulations. In some instances pharmaceutical plants have been forced to cease operations when they did not meet the new wastewater standards. The result has been increased attention and dependence on high-performance water treatment technologies to help meet new wastewater standards.

Case in point is a pharmaceutical plant in China that was manufacturing antibiotics and using an MBR treatment plant with PVDF membranes per the treatment process below:

Raw Water -> Anaerobic Tank -> Aerobic Tank -> Membrane Tank (MBR) -> Discharge

PTFE Membrane Modules at work in pharmaceutical plant in China.
PTFE Membrane Modules at work in pharmaceutical plant in China.

The membrane recovery after chemical cleaning was insufficient as the PVDF membranes never fully returned to their optimal operating conditions. The plant operators were forced to consider adding additional membranes to the water treatment regime, as the plant was not achieving adequate flow to meet operational needs nor water quality requirements.

Sumitomo was invited to the plant to deliver an on-site pilot test using its POREFLON PTFE membrane modules. When placed in the standard operation treatment process, PTFE membranes demonstrated a very high degree of recovery after chemical cleaning with alkalis and acids. Further, the PTFE membrane proved resistant to organic materials and delivered a very stable operation. These are design and operational features of the high-strength, hydrophilic PTFE membrane.

As a result of the pilot test, the plant operator opted to switch from the PVDF membrane to Sumitomo’s PTFE membranes for performance, chemical resistance, ease of installation within the MBR system, and overall lifecycle cost. With PTFE membranes in place, the plant was able to increase its treatment capacity to 4,800 m3/d = 1.27MGD. PTFE membranes were subsequently chosen for installation at additional Chinese pharmaceutical factories.

Water Quality Results with PTFE Membrane

(mg/L) Raw Water Membrane Effluent
CODcr 1000-2000 <100
SS 100-200 <1
TDS 10000 —-