Abstract
In this study, a modified horizontal settling tank with rotating biological discs was developed to treat slightly polluted surface water, and its performance on the simultaneous removal of turbidity, organics, and NH4+-N was investigated on a lab scale. Results show that the effluent quality of the modified settling tank is stable in more than two months of continuous operation. At a hydraulic retention time (HRT) of 2.0 h, 73.65 ± 5.15% turbidity, 53.98 ± 5.17% TOC, and 77.01 ± 10.02%, NH4+-N could be removed by the modified settling tank with an average of 1.96 NTU turbidity, 1.98 mg/L TOC, and 0.46 mg/L NH4+-N residue in the effluent. Due to the improvement in DO supply, higher removal efficiencies of both organics and NH4+-N were achieved with increased disc rotating speed (r < 4 r/min). Further study showed that the genus Hyphomicrobium dominant on the posterior discs and the genus Nitrospira dominant on the anterior discs mainly contributed to the enhanced bio-oxidation of organics and NH4+-N, respectively.
Funder
Land Engineering and Human Settlements Technology Joint Innovation Center of Shaanxi Land Engineering Construction Group Co., Ltd.
Xi’an Jiaotong University
Science Technology Project of Yulin
Subject
Water Science and Technology,Aquatic Science,Geography, Planning and Development,Biochemistry