초록
<P><B>Abstract</B></P> <P>Microalgae coupled with the wastewater treatment and CO<SUB>2</SUB> biofixation becoming a promising biomass feedstock for fermentative hydrogen production. Microbial fuel cells wastewater (MFCW) contained high phosphorus but low nitrogen (N/P is 1:73) due to phosphate buffer. To keep a high microalgae growth rate in MFCW and P removal efficiency, some extra NaNO<SUB>3</SUB> was added into MFCW to balance N/P. With 0.5 g L<SUP>−1</SUP> NaNO<SUB>3</SUB> adding, <I>Chlorella vulgaris</I> showed the highest biomass yield of 4.7 g L<SUP>−1</SUP> and highest lipid productivity of 61.29 mg L<SUP>−1</SUP> d<SUP>−1</SUP>. In order to avoid the inhibition of excess nitrate that added one-time on microalgae growth, NaNO<SUB>3</SUB> was added frequently with small amounts during cultivation. The biomass yield of microalgae by adding NaNO<SUB>3</SUB> twice increased by 13.4% compared to that cultivated by adding the same amount of NaNO<SUB>3</SUB> one-time. Moreover, with a NaNO<SUB>3</SUB> adding frequency of 0.5 g L<SUP>−1</SUP> 3 d<SUP>−1</SUP>, the maximum R = ( <SUB> S 0 </SUB> − <SUB> S t </SUB> ) / ( <SUB> t 0 </SUB> − <SUB> t t </SUB> ) removal rate was up to 45.16 mg L<SUP>−1</SUP> d<SUP>−1</SUP>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An extra sodium nitrate was added to balance the MFCW N/P ratio (1:73). </LI> <LI> <I>Chlorella vulgaris</I> showed the highest biomass yield of 4.7 g L<SUP>−1</SUP>. </LI> <LI> Nitrate was added into MFCW frequently with small amounts during cultivation. </LI> <LI> This nitrate added frequently with small amounts was benefit for P removal. </LI> <LI> The maximum PO 4 − 3 - P removal rate by <I>Chlorella</I> achieved 45.16 mg L<SUP>−1</SUP> d<SUP>−1</SUP>. </LI> </UL> </P>