Characterization and removal of specific organic constituents in an UASB–trickling‐filter system treating domestic wastewater

Abstract

This paper presents the characterization of specific organic constituents (carbohydrates, proteins and lipids) in raw sewage and in the anaerobic and aerobic effluents of a demo-scale (500 inhabitants) UASB- trickling-filter system. The evaluation of such parameters was carried out for two operating conditions, either without sludge recirculation (experiment I) from the trickling filter to the UASB reactor or with sludge recirculation (experiment II), for sludge thickening and stabilization, in the anaerobic reactor. The results showed that the contribution of acetic acid, carbohydrates, proteins and lipids amounted for approximately 70% of the total COD fed to the UASB during experiment I, whereas during experiment II these constituents amounted for only around 40% of the total COD. Although very high BOD and COD overall removal efficiencies were observed for the treatment system (around 90% and 80%, respectively), it was possible to infer that these efficiencies were mainly related to the removal of carbohydrates and lipids (around 80% removal), and of other non-identified constituents. The removal of proteins was much lower (around 50% removal), and the relative contribution of proteins to the total COD increased along the treatment course, being responsible for most of the residual COD of the treatment units. In the present system configuration, the UASB reactor played a major role in the removal of carbohydrates, whereas the trickling filter was very effective in the removal of lipids. The return of aerobic sludge for thickening and stabilization in the UASB reactor did not affect its performance.

Organic matter and nitrogen removal in a hybrid upflow anaerobic sludge blanket—Moving bed biofilm and rope bed biofilm reactor

“…UASB reactors have been observed to give poor performance at low OLRs, due to improper mixing because of low biogas production rate, and the effluent often do not meet discharge standards (Lim & Kim, 2014). To solve these problems related to UASB reactor operation, researchers have started to use hybrid reactors by coupling the UASB reactor with some other treatment technology such as membrane bioreactor (MBR) (Buntner et al, 2013;Qiu et al, 2013), aerated bio-filter (ABF) (Chung et al, 2016), sequencing batch reactor (SBR) (Moawad et al, 2009), activated sludge process (ASP) (Mungray & Patel, 2011), trickling filter (TF) (Pontes & De Lemos Chernicharo, 2011), down-flow hanging system (DHS) (Tandukar et al, 2007) etc.…”

Treatment of Domestic Sewage in an Anaerobic–Aerobic Fixed‐bed Reactor with Recirculation of the Liquid Phase

“…pH in 6.7 AE 0.2 (11) 6.7 AE 0.2 (10) 6.9 AE 0.1 (14) 6.8 AE 0.2 (9) 6.9 AE 0.2 (6) 7.0 AE 0.2 (5) 6.8 AE 0.2 (47) pH e 6.8 AE 0.2 (11) 6.7 AE 0.1 (10) 6.7 AE 0.1 (14) 7.3 AE 0.3 (9) 7.4 AE 0.3 (6) 7.4 AE 0.2 (5) 6.6 AE 0.3 (5) 6.9 AE 0.2 (9) 7.2 AE 0.3 (9) COD in 589 AE 170 (12) 823 AE 180 (10) 597 AE 220 (14) 622 AE 145 (15) 579 AE 121 (16) 627 AE 319 (5) 553 AE 170 (47) COD e 228 AE 73 (12) 255 AE 70 (10) 140 AE 37 (14) 57 AE 27 (15) 44 AE 17 (16) 31 AE 10 (5) 61 AE 24 (5) 57 AE 28 (9) 54 AE 22 (9) COD rem 61 69 77 91 92 95 88 (54) 90 (9) 92 (9) BA in 99 AE 21 (11) 102 AE 15 (10) 119 AE 17 (14) 115 AE 14 (9) 109 AE 16 (6) 119 AE 20 (5) 105 AE 23 (47) BA e 138 AE 25 (11) 162 AE 27 (10) 143 AE 25 (14) 50 AE 27 (9) 41 AE 24 (6) 75 AE 36 (5) 46 AE 34 (5) 90 AE 37 (9) 86 AE 24…”

“…Combining anaerobic and aerobic reactors is a promising alternative to the traditional treatment of industrial wastewaters [1,2] and domestic sewage [3][4][5][6][7][8][9]. Several types of reactors have been combined, including an upflow anaerobic sludge blanket (UASB) reactor and an activated sludge system.…”

Enhancing the nitrogen removal from swine wastewater digested liquid in a trickling biofilter with a soil layer

“…This indicates that the TF process in all of the reactors had a good capacity to resist the organic load impact, which agrees with previous studies. 19,20 The average COD removal rate of the WTF during the stable stages of periods I, II, and III (i.e., day 56 to day 155, day 156 to day 255, and day 256 to day 346, respectively) was 11.0%, 44.2%, and 60.6%, respectively. Meanwhile, the COD removal rate of the GTF during the stable stages of periods I, II, and III was 35.1%, 41.7%, and 60.1%, and that of the STF was 3.9%, 21.7%, and 49.6%, respectively (Fig.…”