Nano Membrane Filtration Technology for sewage treatment

Nano Filtration (NF) Technology for Sewage Treatment

There are two classes of membrane process used in the water and wastewater field. The first category includes reverse osmosis (RO) and nanofiltration (NF). 

Technology

There are two types of membrane filtration technology for water and wastewater treatment, namely ultrafiltration (UF) and microfiltration (MF). UF has pores of 0.01 – 0.02 μm, while MF for water treatment has pores of 0.04 – 0.10 μm. In wastewater applications, coarser MF pore sizes of 0.2 and 0.4 μm can be used, but the finer MF membranes for water duties are also suitable. 

MF removes common particles found in water including bacteria and other microbial organisms, while UF removes viruses in addition, thereby providing a physical disinfection barrier. For RO pre-treatment of wastewater, membrane filtration is normally used in combination with coagulation to control fouling, ensure operational stability and improve removals of dissolved organics.

Conclusions

• Wastewater treated by conventional activated sludge provides a suitable feed for membrane treatment

• The wastewater reuse market is growing rapidly, and provides an opportunity with excellent business potential for membrane filtration

• For wastewater reuse, UF/MF membrane pre-treatment is essential for low cost RO

• The energy cost and Total Water Cost for wastewater reuse is significantly below that of seawater desalination

• MBR – RO has higher energy costs than conventional wastewater treatment followed by UF/MF – RO

• Membrane filtration case studies in wastewater reuse have provided good experience for the water Industry.

 Source of article: http://www.waterworld.com/articles/wwi/print/volume-25/issue-5/regional-spotlight/north-american-caribbean/membrane-filtration-for-wastewater-reuse-current.html