Kinetics of Organic Biodegradation and Biogas Production in the Pilot-Scale Moving Bed Biofilm Reactor (MBBR) for Piggery Wastewater Treatment

Thi Ha Nguyen; Manh Khai Nguyen; Thi Hoang Oanh Le; Thanh Tu Bui; Trong Hieu Nguyen; Truong Quan Nguyen; Anh van Ngo

doi:10.1155/2021/6641796

Kinetics of Organic Biodegradation and Biogas Production in the Pilot-Scale Moving Bed Biofilm Reactor (MBBR) for Piggery Wastewater Treatment

J Anal Methods Chem. 2021 Jan 5:2021:6641796. doi: 10.1155/2021/6641796. eCollection 2021.

Authors

Thi Ha Nguyen¹, Manh Khai Nguyen¹, Thi Hoang Oanh Le¹, Thanh Tu Bui², Trong Hieu Nguyen², Truong Quan Nguyen³, Anh van Ngo¹

Affiliations

¹ Faculty of Environmental Sciences, VNU University of Science, Vietnam National University, Hanoi, Vietnam.
² Faculty of Mathematics, Mechanics and Informatics, VNU University of Science, Vietnam National University, Hanoi, Vietnam.
³ Research Centre for Environmental Technology & Sustainable Development, VNU University of Science, Vietnam National University, Hanoi, Vietnam.

Abstract

In this research, the kinetics of COD biodegradation and biogas production in a moving bed biofilm reactor (MBBR) at pilot scale (10 m³) for piggery wastewater treatment were investigated. Polyethylene (PE) was used as a carrying material, with organic loading rates (OLRs) of 10, 15, and 18 kgCOD/m³ day in accordance to hydraulic retention times (HRTs) of 0.56, 0.37, and 0.3 day. The results showed that a high COD removal efficiency was obtained in the range of 68-78% with the influent COD of 5.2-5.8 g/L at all 3 HRTs. About COD degradation kinetics, in comparison to the first- and second-order kinetics and the Monod model, Stover-Kincannon model showed the best fit with R ² 0.98 and a saturation value constant (K _B ) and a maximum utilization rate (U _max) of 52.40 g/L day and 82.65 g/L day, respectively. The first- and second-order kinetics with all 3 HRTs and Monod model with the HRT of 0.56 day also obtained high R ² values. Therefore, these kinetics and models can be further considered to be used for predicting the kinetic characteristics of the MBBR system in piggery wastewater treatment process. The result of a 6-month operation of the MBBR was that biogas production was mostly in the operating period of days 17 to 80, around 0.2 to 0.3 and 0.15-0.20 L/gCOD_converted, respectively, and then reduction at an OLR of 18 kgCOD/m³. After the start-up stage, day 35 biogas cumulative volume fluctuated from 20 to 30 m³/day and reached approximately 3500 m³ for 178 days during the whole digestive process. Methane is accounted for about 65-70% of biogas with concentration around 400 mg/L.