scholarly journals Change of foulant concentration in an anaerobic membrane bioreactor

2020 ◽  
Author(s):  
Susumu Hasegawa ◽  
Genki Murakami ◽  
Ryosuke Takagi ◽  
Hideto Matsuyama
Keyword(s):  
Liquid Chromatography ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Loading Rate ◽  
Membrane Bioreactors ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Excess Sludge ◽  
Anaerobic Membrane Bioreactors ◽  
High Rejection

Abstract Anaerobic membrane bioreactors (AnMBRs) have many advantages, such as producing methane gas for energy generation and little excess sludge. However, membrane fouling is a serious problem because the foulant, which causes the membrane to foul, may get rejected by the membrane and accumulate in the reactor, resulting in an acceleration of membrane fouling. However, there is no information related to a change in the foulant concentration in an AnMBR. Therefore, we examined the changes in the foulant concentration in the reactor, related to membrane fouling in an AnMBR. For the influent, reactor solution, and effluent, the concentration of each component of the foulant was analyzed by using a liquid chromatography-organic carbon detector (LC-OCD). It was found that fouling in the AnMBR was closely related to the components in the reactor, and the main foulant of the ultrafiltration (UF) membrane was biopolymers (BPs). BP accumulated in the reactor because of a high rejection by the UF membrane. However, once the BP accumulated in the reactor was biodegraded, the concentration of BP decreased with time even under a high organic loading rate of 1.9kg TOC/m3/day.

Impact of Organic Loading Rate and DO on Filamentous Bulking Sludge and the Study of its Characteristics in Membrane Bioreactor

2010 ◽  
Vol 113-116 ◽  
pp. 1280-1284 ◽  
Author(s):  
Yu Tian ◽  
Xin Ying Su ◽  
Lin Chen ◽  
Tian Ling Jiang
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Loading Rate ◽  
Organic Loading Rate ◽  
Filamentous Bacteria ◽  
Organic Loading ◽  
High Substrate Concentration ◽  
Filamentous Bulking ◽  
And Control ◽  
The Impact

The membrane fouling behaviors and fouling mechanism of filamentous bulking sludge in membrane bioreactor (MBR) have been reported in recent studies. However, few studies have been conducted towards the causes and control of filamentous bulking sludge in MBR. In order to make clear the conditions of filamentous bacteria overgrowth in MBR, the impact of DO and organic loading rate on filamentous growth and its characteristics were investigated in this paper. The results showed that overgrowth of filamentous bacteria occurred under a relatively high substrate concentration (organic loading rate was 0.61 KgCOD/(KgMLSS•d), and DO was above 2 mg/L) in MBR. Nutrient removal effect can not be deteriorated under filamentous bulking sludge, with average 95, 57 and 92% removal efficiencies of COD, TN and TP respectively. The particle size of filamentous sludge was larger than that of normal sludge and the filamentous bacteria produced more SMP and EPS than floc forming bacteria.

scholarly journals Investigation of Fats, Oils, and Grease Co-digestion With Food Waste in Anaerobic Membrane Bioreactors and the Associated Microbial Community Using MinION Sequencing

2021 ◽  
Vol 9 ◽  
Author(s):  
Syeed Md Iskander ◽  
Yamrot M. Amha ◽  
Phillip Wang ◽  
Qin Dong ◽  
Juhe Liu ◽  
...  
Keyword(s):  
Microbial Community ◽  
Loading Rate ◽  
Biogas Production ◽  
Relative Activity ◽  
Membrane Bioreactors ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Two Phase ◽  
Anaerobic Membrane Bioreactors ◽  
Oils And Grease

Co-digestion of fats, oils, and grease (FOG) with food waste (FW) can improve the energy recovery in anaerobic membrane bioreactors (AnMBRs). Here, we investigated the effect of co-digestion of FW and FOG in AnMBRs at fat mass loading of 0.5, 0.75, and 1.0 kg m–3 day–1 with a constant organic loading rate of 5.0 gCOD L–1 day–1 in both a single-phase (SP) and two-phase (TP) configuration. A separate mono-digestion of FW at an identical organic loading rate was used as the benchmark. During co-digestion, higher daily biogas production, ranging from 4.0 to 12.0%, was observed in the two-phase methane phase (TP-MP) reactor compared to the SP reactor, but the difference was statistically insignificant (p > 0.05) due to the high variability in daily biogas production. However, the co-digestion of FW with FOG at 1.0 kg m–3 day–1 fat loading rate significantly (p < 0.05) improved daily biogas production in both the SP (11.0%) and TP (13.0%) reactors compared to the mono-digestion of FW. Microbial community analyses using cDNA-based MinION sequencing of weekly biomass samples from the AnMBRs revealed the prevalence of Lactobacillus (92.2–95.7% relative activity) and Anaerolineaceae (13.3–57.5% relative activity), which are known as fermenters and fatty acid degraders. Syntrophic fatty acid oxidizers were mostly present in the SP and TP-MP reactors, possibly because of the low pH and short solid retention time (SRT) in the acid phase digesters. A greater abundance of the mcrA gene copies (and methanogens) was observed in the SP and MP reactors compared to the acid-phase (AP) reactors. This study demonstrates that FW and FOG can be effectively co-digested in AnMBRs and is expected to inform full-scale decisions on the optimum fat loading rate.

Fouling in a novel airlift oxidation ditch membrane bioreactor (AOXMBR) at different high organic loading rate

2013 ◽  
Vol 105 ◽  
pp. 69-78 ◽  
Author(s):  
Farshid Pajoum Shariati ◽  
Mohammad Reza Mehrnia ◽  
Mohammad Hossein Sarrafzadeh ◽  
Sara Rezaee ◽  
Alain Grasmick ◽  
...  
Keyword(s):  
Membrane Bioreactor ◽  
Loading Rate ◽  
Organic Loading Rate ◽  
Oxidation Ditch ◽  
Organic Loading ◽  
Airlift Oxidation Ditch

Feasibility of submerged anaerobic membrane bioreactor (SAMBR) for treatment of low-strength wastewater

2008 ◽  
Vol 58 (10) ◽  
pp. 1925-1931 ◽  
Author(s):  
Z. Huang ◽  
S. L. Ong ◽  
H. Y. Ng
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactors ◽  
Organic Loading Rate ◽  
Effluent Quality ◽  
Significant Difference ◽  
Anaerobic Membrane Bioreactors ◽  
High Purification ◽  
Low Strength ◽  
Set Up ◽  
Internal Pore

Two 6-L submerged anaerobic membrane bioreactors (SAMBR) with SRT of 30 and 60 d (denoted as R30 and R60, respectively) were set up and operated for five months, with a mixture of glucose as substrate. Feasibility of SAMBR was studied for treatment of low-strength wastewater. First two months were identified as acclimation stage. A COD removal efficiency was achieved stably at around 99% and biogas productions were maintained at 0.023 and 0.028 L CH4/gMLVSS∙d for R30 and R60, respectively. Even though R60 contained higher MLVSS concentration, no significant difference of treatment performances between both reactors was found due to the low organic loading rate and high purification function of membrane. In the investigation of membrane fouling, less irreversible fouling was observed for R30 compared to R60. High non-flocculent concentration of R60 would be responsible for membrane internal pore blocking and deteriorated effluent quality.

Fouling cake layer in a submerged anaerobic membrane bioreactor treating saline wastewaters: curse or a blessing?

2011 ◽  
Vol 63 (12) ◽  
pp. 2902-2908 ◽  
Author(s):  
I. Vyrides ◽  
D. C. Stuckey
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Large Fraction ◽  
Membrane Bioreactors ◽  
Extracellular Polysaccharides ◽  
Cake Layer ◽  
Anaerobic Membrane Bioreactors ◽  
Suspended Biomass ◽  
Microbial Products

The treatment of inhibitory (saline) wastewaters is known to produce considerable amounts of soluble microbial products (SMPs), and this has been implicated in membrane fouling; the fate of these SMPs was of considerable interest in this work. This study also investigated the contribution of SMPs to membrane fouling of the; (a) cake layer/biofilm layer, (b) the compounds below the biofilm/cake layer and strongly attached to the surface of the membrane, (c) the compounds in the inner pores of the membrane, and (d) the membrane. It was found that the cake/biofilm layer was the main reason for fouling of the membrane. Interestingly, the bacteria attached to the cake/biofilm layer showed higher biodegradation rates compared with the bacteria in suspension. Moreover, the bacteria attached to the cake layer showed higher amounts of attached extracellular polysaccharides (EPS) compared with the bacteria in suspension, possibly due to accumulation of the released EPS from suspended biomass in the cake/biofilm layer. Molecular weight (MW) analysis of the effluent and reactor bulk showed that the cake layer can retain a large fraction of the SMPs in the reactor and prevent them from being released into the effluent. Hence, while cake layers lead to lower fluxes in submerged anaerobic membrane bioreactors (SAMBRs), and hence higher costs, they can improve the quality of the reactor effluent.

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