Removal of Nitrate from Wastewater Using Trentepohlia Aurea Microalgae

摘要

Wastewater treatment using microalgae is an advanced new method of wastewater treatment. Experiments on removing of nitrate (NO_3~-) from wastewater using Trentepohlia aurea microalgae were reported under continuous light in batch and continuous system. Moreover, after several trails and experiments the results provide that in batch system the removal of nitrate from wastewater under continuous light of about 3500 Lux was more remarkable than in continuous system. The results show the removal efficiencies of some nutrients such as nitrogen, phosphorous and nitrate from wastewater reached high efficiencies. In addition, the efficiency of chemical oxygen demand (COD) rose dramatically and reached 97.11% during a period of six days as far as the pH which increases rapidly from 7.5 up to 10.9. When the microalgae were placed in medium with wastewater it showed a high growth in Trentepohlia aurea microalgae. The growing rate of microalgae had been noticed to be very fast with very high concentration of nitrate in water. NO_3~- is a water-soluble molecule made up of nitrogen and oxygen. It is formed when nitrogen from ammonia or other sources combines with oxygenated water. A special type of microalgae called Trentepohlia aurea which growth on tree branches and rocks with brown color used for removal of NO_3~- from wastewater. The experimental data show that the percent of NO_3~- removed using Trentepohlia aurea microalgae is 37% during 30 days. From these results, Trentepohlia aurea microalgae are consider as a potential for wastewater treatment.