Kinetics of organic and nutrient degradation with microalgae biomass cultured in photobioreactors

Photobioreactor is one of the microalgae-based wastewater treatments that can degrade organic and nutrient. This study aims to determine the rate of removal (pseudo-first-order reaction) and removal of COD, ammonia, nitrate, and phosphate in photobioreactor use cultured microalgae. In this research, reactor was divided into three initial organic pollutant concentrations, namely 50 mg/L (r1); 100 mg/L (r2); and 150 mg/L (r3). The volume of wastewater in the reactor is 15 L and is operated for 12 days with batch system. The results of the COD removal rate increased from r1 to r3 with a value of 0.094 d
^-1
; 0.105 d
^-1
; and 0.164 d
^-1
. Ammonia removal rate from r1 to r3 is 0.396 d
^-1
; 0.338 d
^-1
; and 0.380 d
^-1
. Nitrate and phosphate removal amounted to 74.03% -86.27% and 54.76% -66.52%. The initial concentrations of DO is 3.2 mg/L -3.6 mg/L increased to 6 -6.5 mg/L. The pH value with initials 7.8 -7.9 changes to 9.3 -9.5.