Core Application Scenarios of Organic Membranes in Environmental Protection

Water Treatment: Pollutant Removal and Water Quality Improvement

Industrial Wastewater Treatment – Organic membranes can effectively remove organic pollutants (such as dyes, detergents, and heavy metal chelates), pathogens, and suspended particles from wastewater through ultrafiltration, nanofiltration, or reverse osmosis technologies. For example, in a dye wastewater treatment experiment, an Sb-SnO₂ polyethersulfone electrocatalytic organic membrane was used to degrade Direct Red 31 dye, significantly reducing pollutant concentrations to meet discharge standards.

Domestic Sewage Treatment and Reuse – Membrane separation technologies (such as the combined ultrafiltration and nanofiltration process) can treat hotel laundry wastewater by removing organic pollutants including body secretions and synthetic detergents. The treated effluent can be reused for laundry, landscaping, or toilet flushing, increasing the reuse rate to over 70% and reducing water waste.

Seawater and Brackish Water Desalination – Reverse osmosis organic membranes can retain salts and organic pollutants from seawater to achieve desalination; nanofiltration technology is suitable for brackish water desalination while retaining some beneficial minerals to produce freshwater that meets drinking standards.

Sludge Treatment and Resource Recovery

Sludge Concentration – Organic membranes achieve moisture separation by retaining solid particles in sludge, reducing the moisture content from 90% to below 60% and lowering subsequent treatment costs.

Resource Utilization – The concentrated sludge can be converted into biomass energy (such as biogas) through anaerobic digestion or pyrolysis, or used as organic fertilizer in agriculture, effectively "turning waste into treasure."

Technical Advantages of Organic Membranes in Environmental Applications

High Separation Performance – Organic membranes achieve rejection rates of over 90% for pollutants, with particularly superior removal of small-molecule organic compounds (such as pesticides and endocrine disruptors) compared to traditional precipitation or adsorption methods.

Low Energy Consumption and Environmental Friendliness – The membrane separation process requires no high temperature or high pressure, reducing energy consumption by 30%–50% compared to distillation methods, while avoiding secondary pollution from chemical agents.

Simple Operation and Modular Design – Membrane modules can be flexibly combined to suit different scales of wastewater treatment needs, with a high degree of automation and low maintenance costs.

Strong Water Quality Stability – Treated effluent quality remains stable despite fluctuations in influent quality, consistently meeting reuse or discharge standards. For example, reverse osmosis effluent total dissolved solids (TDS) can be controlled below 50 mg/L.

Challenges and Development Trends

Existing Challenges

Membrane Fouling – Organic pollutants tend to adsorb onto the membrane surface or clog pores, leading to flux decline and shortened service life. Solutions include pretreatment (such as micro-flocculation filtration), periodic cleaning (chemical cleaning or ultrasonic cleaning), or developing anti-fouling membrane materials.

Cost and Durability Balance – High-performance organic membranes (such as graphene composite membranes) have relatively high material costs, and their long-term stability still requires improvement, limiting large-scale application.

Future Development Directions

Novel Membrane Material Development – Incorporating nanomaterials such as graphene and carbon nanotubes into organic membrane substrates (such as polydimethylsiloxane) to enhance hydrophobicity, corrosion resistance, and anti-fouling performance.