Nitrate and phosphate removal from treated wastewater byChlorella vulgarisunder various light regimes within membrane flat plate photobioreactor

The membrane photobioreactor (MPBR) is a well-operated system concerning microalgae cultivation and nutrients assimilation from wastewater effluent. In the present paper, a sample of pulp and paper wastewater was primarily treated by activated sludge system (ACS), and the concentration of nitrate and phosphate decreased as about 26 and 10%, respectively. Then, it was transferred into six flat plate MPBR systems with 5 L capacity and 0.45 mu m membrane pore size for the secondary treatment process (nitrate and phosphate assimilation) byChlorella vulgaris(green microalgae) species during six cultivation periods. In this section, the effects of different light intensities (100 and 300 mu mol m(-2)s(-1)) and light-dark cycles (24-0, 16-8, and 12-12) on nitrate and phosphate uptake through the treated pulp and paper wastewater effluent after 24 hr were investigated. The maximum photosynthetic productivity and nitrate-phosphate removals after 24 hr (nitrate: 57% and phosphate: 43%) were recorded for the culture under 300 mu mol m(-2)s(-1)and 24-0 light-dark regime within the MPBR system.