TY  - JOUR
AB  - Municipal wastewater (MWW) was treated using a microalgal?bacterial consortium without mechanical aeration. An inoculum for the reactor was prepared by acclimatizing Chlorella vulgaris to MWW and supplementing with a small amount of activated sludge. The hydraulic retention time (HRT) and solids retention time (SRT) were progressively reduced from 6.67 to 1.17 d and from 10 to 6.67 d, respectively, to test the process robustness under realistic MWW operation. The COD removal efficiency was 88% at 0.23 kg-COD/m3/d. Mass balance suggested the major nitrogen and phosphorus removal mechanism as assimilation. A high percentage (80%) of oxidized nitrogen indicated an efficient nitrification at all HRTs. Inorganic carbon (IC) balance calculation explained the observed IC dynamics. The chlorophyll a-to-mixed liquor volatile suspended solids (MLVSS) ratio and percentage of nitrite responded to IC limitation and supplementation. The mixed liquor exhibited excellent settleability (sludge volume index: 42 mL/g) with dense algal?bacterial flocs. An increased organic loading rate, however, reduced daytime dissolved oxygen, suggesting limitation under non-aerated conditions. These findings demonstrate the potential of microalgal?bacterial systems to achieve efficient COD removal and nitrification at realistic HRTs without aeration while emphasizing the importance of IC management.
AU  - Thiruchchelvam, T
AU  - Johir, M
AU  - Krishna, KCB
AU  - Sathasivan, A
DA  - 2026/12/24
DO  - 10.3390/w18010057
JO  - WATER
PB  - MDPI
PY  - 2026/12/24
TI  - Effects of Hydraulic Retention and Inorganic Carbon During Municipal Wastewater Treatment Using a Microalgal Bacterial Consortium
VL  - 18
Y1  - 2026/12/24
Y2  - 2026/06/17
ER  -