Acta Scientiarum Polonorum. Formatio Circumiectus (Nov 2022)
Assessment the livestock wastewater treatment efficiency of the anaerobic digester combined with the biological pond in Nam Anh, Nghe An, Vietnam
Abstract
Aim of the study: This study focuses on assessing the efficiency of the anaerobic digester combined with biological pond to provide overview data and can be used as a reference for similar studies in Nghe An province. Material and methods: Wastewater properties at 3 stages of livestock wastewater treatment process (input, after digester, after biological pond) in Nam Anh were investigated. A total of 81 samples were collected across 9 locations between March and May 2020. Shapiro-Wilk test (α = 0.05), Kruskal-Wallis test and Dunn test (α = 0.05) was preformed to estimate the significance differences. Cluster analysis was utilized to compare the parameters between the sampling locations and to classify the locations. Results and conclusions: The results showed that all parameters exceeded the allowable limit many times specified by QCVN 40:2011/BTNMT and TCN 678 – 2006. The wastewater after being treated by anaerobic digester was significantly reduced. The treatment efficiency for BOD5 was 66-73%, COD was 74-80%, SS reached 78-84%, reaching 10-27% for TN, 7-25% for TP and coliform ranged from 28.2-85.3%. Wastewater after being treated through the digester combined with the biological pond had a very high treatment efficiency: 95 - 97% for BOD5, 96- 97% with COD, SS was up to 96-97%, 45 - 57% with TN, 35 - 70% with TP and coliforms reached 77.4 - 98.4%. The treatment efficiency had a linear correlation between object locations. Applying anaerobic digestion in combination with biological pond has proven to be a highly effective solution, and should be prioritized in the treatment of livestock wastewater.
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