Effect of solids retention time on membrane fouling intensity in two-stage submerged anaerobic membrane bioreactors treating palm oil mill effluent

2014 ◽  
Vol 35 (20) ◽  
pp. 2634-2642 ◽  
Author(s):  
S. Annop ◽  
P. Sridang ◽  
U. Puetpaiboon ◽  
A. Grasmick
Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1525
Author(s):  
Santiago Pacheco-Ruiz ◽  
Sonia Heaven ◽  
Charles J. Banks

Four flat-sheet submerged anaerobic membrane bioreactors ran for 242 days on a simulated domestic wastewater with low Chemical Oxygen Demand (COD) and high suspended solids. Organic loading was maintained around 1.0 g COD L−1 day−1, while solids retention time (SRT) was varied from 20–90 days. This was achieved at a constant membrane flux, maintained by adjusting transmembrane pressure (TMP) in the range 1.8-9.8 kPa. Membrane fouling was assessed based on the required TMP, with mixed liquors characterised using capillary suction time, frozen image centrifugation and quantification of extracellular polymeric substances (EPS). SRT had a significant effect on these parameters: fouling was least at an SRT of 30 days and highest at 60 days, with some reduction as this extended to 90 days. Operation at SRT <30 days showed no further benefits. Although operation at a short SRT was optimal for membrane performance it led to lower specific methane productivity, higher biomass yields and higher effluent COD. Short SRT may also have accelerated the loss of essential trace elements, leading to reduced performance under these conditions. A COD-based mass balance was conducted, including both biomass and methane dissolved in the effluent.


2020 ◽  
Vol 10 (1) ◽  
pp. 11-16
Author(s):  
Laily Isna Ramadhani ◽  
Sri Ismiyati Damayanti ◽  
Hanifrahmawan Sudibyo ◽  
Muhammad Mufti Azis ◽  
Wiratni Budhijanto

Indonesia is currently the most significant crude palm oil (CPO) producer in the world. In the production ofCPO, 0.7m3 of Palm Oil Mill Effluent (POME) is emitted as the wastewater for every ton of fresh fruit bunches processed in the palm oil mill.With the increasing amount of CPO production, an effective POME treatment system is urgently required to prevent severe environmental damage. The high organic content in the POME is a potential substrate forbio-methane production. The biomethane production is carried out by two groups of microbes, i.e., acidogenic and methanogenic microbes. Each group of bacteria performs optimally at different optimum conditions. To optimize the biomethane production, POME was treated sequentially by separating the acidogenic and methanogenic microbes into two stages of anaerobic fluidized bed reactors (AFBR). The steps were optimized differently according to the favorable conditions of each group of bacteria. Although perfect separation cannot be achieved, this study showed that pH control could split the domination of the bacteria, i.e., the first stage (maintained at pH 4-5) was dominated by the acidogenic microbes and the second stage (kept neutral) was governed by methanogens. In addition to the pH control, natural zeolitewas added as microbial immobilization media in the AFBR to improve the performance of the microorganisms, especially in preventing microbial wash out at short hydraulic retention time (HRT). This study was focused on the understanding of the effect of HRT on the performance of steady-state continuous AFBR. The first stage as the acidogenic reactorwas rununder acidic conditions (pH 4-5) at five different HRTs. In comparison, the second stage as the methanogenic reactorwasrun under the neutral condition at four different HRTs. In this work,short HRT (5 days) resulted in better performance in both acidogenic AFBR and methanogenic AFBR. The immobilization media was hence essential to reduce the risk of washout at such a short HRT. The two-stage system also resulted in quite a high percentage of soluble chemical oxygen demand (sCOD) removal, which was as much as 96.06%sCOD.


2017 ◽  
Vol 76 (6) ◽  
pp. 1389-1398 ◽  
Author(s):  
Choon Aun Ng ◽  
Ling Yong Wong ◽  
Huey Yee Chai ◽  
Mohammed J. K. Bashir ◽  
Chii-Dong Ho ◽  
...  

Three different sizes of powdered activated carbon (PAC) were added in hybrid anaerobic membrane bioreactors (AnMBRs) and their performance was compared with a conventional AnMBR without PAC in treating palm oil mill effluent. Their working volume was 1 L each. From the result, AnMBRs with PAC performed better than the AnMBR without PAC. It was also found that adding a relatively smaller size of PAC (approximately 100 μm) enhanced the chemical oxygen demand removal efficiency to 78.53 ± 0.66%, while the concentration of mixed liquor suspended solid and mixed liquor volatile suspended solid were 8,050 and 6,850 mg/L, respectively. The smaller size of PAC could also enhance the biofloc formation and biogas production. In addition, the smaller particle sizes of PAC incorporated into polyethersulfone membrane resulted in higher performance of membrane fouling control and produced better quality of effluent as compared to the membrane without the addition of PAC.


2020 ◽  
Vol 201 ◽  
pp. 78-85
Author(s):  
Chee Yong Tai ◽  
Salahaldin M.A. Abuabdou ◽  
Choon Aun Ng ◽  
Chin Heng Gan ◽  
Mohammed J.K. Bashir

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
S. Annop ◽  
P. Sridang ◽  
P. Chevakidagarn ◽  
K. Nopthavorn

The main objective was to compare the performances and the removal efficiencies of two biological treatment systems, a submerged membrane bioreactor (SMBR) and a simultaneous activated sludge (AS), for treating Palm Oil Mill Effluent (POME). Two lab scale units of SMBR and AS with a working volume of 24 L were operated under favorable biological conditions and minimized membrane fouling intensity. To achieve both carbonaceous and nitrogen removal, the cyclic air intermittent and dissolved oxygen control were performed into SMBR and AS with the influent flow rate about 16 L/d respectively. In terms of organic removal and membrane performance, the SMBR showed good removal efficiency to treat high strength wastewater with organic loading variation of POME. The average removal rates of TCOD, BOD, Turbidity, Color, Oil and Grease, NH3–N, TKN were 69±2, 76±2, 100±1, 37±21, 92±6, 67±4 and 75±10% respectively. Results pointed out the benefit of membranes retained totally the active compositions of biomass in each stage of development. The AS showed the limitation of sedimentation phase for sludge and oil separation. The characteristics of sludge in SMBR showed healthy floc formations and good settling after 240 h. The concentrations of COD and BOD in permeate were around 870±53 and 37±13 mg/L.


2019 ◽  
Vol 44 (6) ◽  
pp. 3347-3355 ◽  
Author(s):  
Jiravut Seengenyoung ◽  
Chonticha Mamimin ◽  
Poonsuk Prasertsan ◽  
Sompong O-Thong

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