Abstract
Membrane processes provide a powerful technique for solvent and solute recovery from dilute (Reverse Osmosis, RO; Nanofiltration, NF; Ultrafiltration, UF) to concentrated (Pervaporation, PV) solutions. The special features for membrane processes that make them attractive for environmental applications are their compactness, ease of fabrication, operation, and modular design. Considerable volume reduction of waste streams is also possible with membranes (for example, 30 fold for RO and up to 1000 fold for PV). Removal of heavy metals, arsenic, nitrates, and other inorganics is of immense interest for drinking water production and also for dilute aqueous systems. Although many conventional techniques (i.e., ion exchange, precipitation, inorganic adsorbents, etc.) are effective for removing some of these pollutants, they are limited in their capacity to accomplish simultaneous removal of all species (including natural organics and pesticides). This deals with the applications of RO/NF/PV, and novel functionalized (with polymeric ligands) microfiltration membranes. The results of high performance zeolite pervaporation membranes showed high water flux and outstanding water/organic solvent selectivity. With a new generation aromatic polyamide and other composite RO membranes, rejection of heavy metals such as Pb and As(V) are greater than 98% and nitrate rejections range between 95-97%. Novel microfiltration based metal sorbents with capacities considerably higher than conventional ion exchange have been developed.
| Original language | English |
|---|---|
| Pages (from-to) | 61-66 |
| Number of pages | 6 |
| Journal | Journal of the Chinese Institute of Chemical Engineers |
| Volume | 33 |
| Issue number | 1 |
| State | Published - Jan 2002 |
Keywords
- Fuctionalized membrane
- Nanofiltration
- Pervaporation
- Reverse osmosis
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering