Analysis and evaluation: Applicability of the constructed wetland for piggery wastewater treatment after biogas process

Abstract

    In Vietnam, the common technique used for piggery wastewater treatment is biogas model. However,from actual operations, this model results higher than the permitted standard - QCVN 62-MT:2016/BTNMT. Acknowledging the current situation, this study focuses on the application of theconstructed wetland (CW) to treat piggery wastewater after biogas process. The CW using reed(Phragmites australis Cav.) and the filter system consisting of gravel, limestone and rice husk. From theexperimental results, the pHs value of the wastewater stable in the range of 6.9 to 7.2, meeting thepermitted standards. The removal efficiency of total phosphorus is up to 86% while the otherparameters, namely TSS, COD, Total Nitrogen and Ammonium after 168 hours experiment have theefficiency 78%, 74.6%, 67.1% and 74.2%, respectively. Therefore, the proposed constructed wetlandshows various advantages, which higher treatment efficiency and shorter retention time for the piggerywastewater treatment after biogas.