Reuse of Organic Matter from Coagulated Sludge Using a Membrane-Coupled Anaerobic Organic Acid Fermentor in Advanced Municipal Wastewater Treatment

Abstract

This study focused on the development of an advanced municipal wastewater treatment process using a membrane-coupled anaerobic organic acid fermentor (MAOF) to remove dissolved organic matter from coagulated sludge. Intermittent ozone bubbling was effective in preventing increases in permeation resistance that were caused by particle accumulation on the membrane surface and in maintaining a high permeation flux. With regard to taxonomy, approximately 20 isolates were identified in the MAOF and are believed to represent the principal cell types in the fermentor. MAOF, coupled with intermittent ozone bubbling, is an effective system that can be implemented to recover organic matter that is used in biological denitrification or other basic materials.

Anaerobic membrane bioreactors for sludge digestion: Current status and future perspectives

“…DM layer has an important role in particles rejection in anaerobic dynamic membrane bioreactors (AnDMBRs) (Ersahin et al, 2014). Up to now, PVDF (Zheng et al, 2018), PES (Ghyoot & Verstraete, 1997;Martin-Ryals et al, 2020), polysulfone (Joo et al, 2016;Kim et al, 2017;Liew Abdullah et al, 2005), polythene (Li et al, 2015;Xu et al, 2010Xu et al, , 2011, polytetrafluoroethylene (Hafuka et al, 2016(Hafuka et al, , 2019, ceramic (Kayawake et al, 1991;Kim & Chung, 2012;Kim et al, 2005;Kim & Somiya, 2001a, 2001bKim, Somiya, et al, 2002;Meabe et al, 2013) and stainless steel (Kim & Jung, 2007) membranes, and DMs using different support materials such as nylon mesh (Joo et al, 2016), Dacron meshes (Yu et al, 2014(Yu et al, , 2016, silk filter (Liu et al, 2016), woven fabric filter (Kooijman et al, 2017) and woven fiber filter (Pillay et al, 1994) have been used for solid-liquid separation in AnMBRs treating sludge. Most of the membrane types applied in AnMBRs for sludge filtration were ultrafiltration (UF) and microfiltration (MF) membranes with a configuration of tubular, hollow fiber, flat sheet or monolithic.…”

“…Ozone has an effect not only on membrane fouling but also on treatment performance and microbial activity. Kim and Chung (2012) applied intermittent ozonation before the membrane unit in an external AnMBR fermenting coagulated primary sludge for recovery of VFAs. Reduction in concentration of refractory substances and improvement in solubilization of solids were observed after ozone application.…”

“…Pretreatment by ozonation may increase the efficiency of sludge digestion enabling higher biogas production and phosphorous recovery from liquid fraction (Chu et al, 2009;Erden & Filibeli, 2011). Furthermore, VFA recovery from sludge fermentation has been examined by a few researchers (Kim & Chung, 2012;Kim & Jung, 2007;Liu et al, 2016). VFAs can be used as a carbon source for nitrification and denitrification in WWTPs, and for bioplastic production (Lee et al, 2014).…”