Effect of sludge retention time on membrane bio-fouling using different type and pore size of membranes in a submerged membrane bioreactor

2013 ◽  
Vol 67 (3) ◽  
pp. 604-611 ◽  
Author(s):  
Nadir Dizge ◽  
Derya Y. Koseoglu-Imer ◽  
Ahmet Karagunduz ◽  
Bulent Keskinler
Keyword(s):  
Steady State ◽  
Retention Time ◽  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Organic Loading Rate ◽  
Submerged Membrane Bioreactor ◽  
Sludge Retention Time ◽  
Carbohydrate Concentration ◽  
Activated Sludge Reactor ◽  
Microfiltration Membranes

The objective of this study was to investigate the influence of sludge retention time (SRT) on membrane bio-fouling. An activated sludge reactor was operated at three different SRTs (10, 30, and 50 days). Submerged membrane experiments were performed when the mixed liquor suspended solids (MLSS) concentration reached the steady state conditions. MLSS concentrations reached the steady state at 3,109 ± 194, 6,209 ± 123 and 6,609 ± 280 mg/L for SRTs of 10, 30 and 50 days, respectively. The total soluble microbial products (SMP) were 20.1 ± 3.7, 16.2 ± 7.2 and 28.2 ± 8.4 mg/L at SRTs of 10, 30, and 50 days, respectively. The carbohydrate concentration in the supernatant was about two times more for SRT of 10 days than that for 50 days. The total amount of extracellular polymeric substances (EPS) extracted from the flocs were approximately 74.9 ± 11.9, 67.8 ± 15.0 and 67.5 ± 17.4 mg/g MLSS at three SRTs (10, 30, and 50 days) under the same organic loading rate. The viscosity of the biomass increased with the increasing SRT. The results of flux stepping tests showed that the membrane fouling at SRT 10 days was always higher than that of 30 and 50 days. Four different microfiltration membranes (cellulose acetate, polyethersulfone, mixed ester, and polycarbonate) with three different pore sizes (0.45, 0.22, 0.10 μm) were tested. Filtration resistances were determined for each membrane. Cake resistance was observed to be the most significant fouling mechanism for all membranes.

scholarly journals The investigation of paper mill industry wastewater treatment and activated sludge properties in a submerged membrane bioreactor

2017 ◽  
Vol 76 (7) ◽  
pp. 1715-1725 ◽  
Author(s):  
Hanife Sari Erkan ◽  
Guleda Onkal Engin
Keyword(s):  
Retention Time ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Experimental Studies ◽  
Paper Mill ◽  
Calcium Accumulation ◽  
Submerged Membrane Bioreactor ◽  
Paper Mill Wastewater ◽  
Industry Wastewater

The paper mill industry produces high amounts of wastewater and, for this reason, stringent discharge limits are applied for sustainable reclamation and reuse of paper mill industry wastewater in many countries. Submerged membrane bioreactor (sMBR) systems can create new opportunities to eliminate dissolved substances present in paper mill wastewater including. In this study, a sMBR was operated for the treatment of paper mill industry wastewater at 35 h of hydraulic retention time (HRT) and 40 d of sludge retention time (SRT). The chemical oxygen demand (COD), NH3-N and total phosphorus (TP) removal efficiencies were found to be 98%, 92.99% and 96.36%. The results demonstrated that sMBR was a suitable treatment for the removal of organic matter and nutrients for treating paper mill wastewater except for the problem of calcium accumulation. During the experimental studies, it was noted that the inorganic fraction of the sludge increased as a result of calcium accumulation in the reactor and increased membrane fouling was observed on the membrane surface due to the calcification problem encountered. The properties of the sludge, such as extracellular polymeric substances (EPS) and soluble microbial products (SMP), relative hydrophobicity, zeta potential and floc size distribution were also monitored. According to the obtained results, the total EPS was found to be 43.93 mg/gMLSS and the average total SMP rejection by the membrane was determined as 66.2%.

Effects of Sludge Retention Time on the Characteristics of Mixed Liquor and Membrane Fouling in Membrane Bioreactor

2010 ◽  
Vol 113-116 ◽  
pp. 2057-2061 ◽  
Author(s):  
Zhan Ping Cao ◽  
Jing Li Zhang ◽  
Hong Wei Zhang
Keyword(s):  
Zeta Potential ◽  
Retention Time ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Volume Index ◽  
Bacterial Surface ◽  
Sludge Retention Time ◽  
Dominant Bacteria

In the membrane bioreactor (MBR) treating municipal wastewater, the effect of sludge retention time (SRT) on the contents of the extracellular polymeric substances (EPS), tightly bound EPS (TB) and loosely bound EPS (LB) and the ratios of protein and polysaccharide in TB and LB was studied. With the extension of SRT the EPS increased and the ratios of protein and polysaccharide in TB and LB changed. The above changes influenced the charge distribution of bacterial surface, increased the proportion of hydrophilicity and hydrophobicity on the bacterial surface, changed the bacteria from the instable (R-type) to the stable (S-type), decreased the Zeta potential and increased the values of sludge volume index (SVI). The correlation analysis for the main parameters of fouling resistance was performed by SPSS software, and it was found that the correlation coefficient (rp) was -0.818 for Zeta potential, 0.853 for the content of suspended solids in supernatant and 0.832 for relative hydrophobicity, respectively. SRT of the MBR should be controlled below 120 times of the minimum generation-time of dominant bacteria considering the membrane fouling and sludge characteristics.

Effect of 200 days' sludge retention time on performance of a pilot scale submerged membrane bioreactor for high strength industrial wastewater treatment

2006 ◽  
Vol 53 (11) ◽  
pp. 269-276 ◽  
Author(s):  
C.T. Hay ◽  
D.D. Sun ◽  
S.L. Khor ◽  
J.O. Leckie
Keyword(s):  
Retention Time ◽  
Industrial Wastewater ◽  
Membrane Bioreactor ◽  
Hydraulic Retention Time ◽  
High Strength ◽  
Pilot Scale ◽  
Submerged Membrane Bioreactor ◽  
Sludge Retention Time ◽  
Organic Removal ◽  
Sludge Concentration

A high strength industrial wastewater was treated using a pilot scale submerged membrane bioreactor (MBR) at a sludge retention time (SRT) of 200 d. The MBR was operated at a high sludge concentration of 20 g/L and a low F/M ratio of 0.11 during 300 d of operation. It was found that the MBR could achieve COD and TOC overall removal efficiencies at more than 99 and 98% TN removal. The turbidity of the permeate was consistently in the range of 0.123 to 0.136 NTU and colour254 absorbance readings varied from 0.0912 to 0.0962 a.u. cm−1. The sludge concentration was inversely proportional to the hydraulic retention time (HRT), yielded excellent organic removal and extremely low sludge production (0.0016 kgVSS/day).

Treatment of a chocolate industry wastewater in a pilot-scale low-temperature UASB reactor operated at short hydraulic and sludge retention time

2013 ◽  
Vol 67 (6) ◽  
pp. 1353-1361 ◽  
Author(s):  
M. Esparza-Soto ◽  
O. Arzate-Archundia ◽  
C. Solís-Morelos ◽  
C. Fall
Keyword(s):  
Low Temperature ◽  
Retention Time ◽  
Biogas Production ◽  
Pilot Scale ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Processing Industry ◽  
Sludge Retention Time ◽  
Industry Wastewater

The aim of this work was to evaluate the performance of a 244-L pilot-scale upflow anaerobic sludge blanket (UASB) reactor during the treatment of chocolate-processing industry wastewater under low-temperature conditions (18 ± 0.6 °C) for approximately 250 d. The applied organic loading rate (OLR) was varied between 4 and 7 kg/m3/d by varying the influent soluble chemical oxygen demand (CODsol), while keeping the hydraulic retention time constant (6.4 ± 0.3 h). The CODsol removal efficiency was low (59–78%). The measured biogas production increased from 240 ± 54 to 431 ± 61 L/d during the experiments. A significant linear correlation between the measured biogas production and removed OLR indicated that 81.69 L of biogas were produced per kg/m3 of CODsol removed. Low average reactor volatile suspended solids (VSS) (2,700–4,800 mg/L) and high effluent VSS (177–313 mg/L) were derived in a short sludge retention time (SRT) (4.9 d). The calculated SRT was shorter than those reported in the literature, but did not affect the reactor's performance. Average sludge yield was 0.20 kg-VSS/kg-CODsol. The low-temperature anaerobic treatment was a good option for the pre-treatment of chocolate-processing industry wastewater.

Correct manipulation method of MBR operating parameters in membrane fouling studies

2013 ◽  
Vol 68 (10) ◽  
pp. 2301-2308 ◽  
Author(s):  
N. Kayaalp ◽  
C. Kinaci
Keyword(s):  
Retention Time ◽  
Membrane Fouling ◽  
Organic Loading Rate ◽  
Utilization Rate ◽  
Operating Parameters ◽  
Oxygen Utilization ◽  
Membrane Area ◽  
Membrane Flux ◽  
Oxygen Utilization Rate ◽  
Common Application

In this study, various parameter manipulation methods, variable sludge retention time (SRT)–variable mixed liquor suspended solids (MLSS) concentration, constant SRT–variable MLSS concentration and variable SRT–constant MLSS concentration, were compared based on the interrelationships among the following membrane bioreactor operating parameters: SRT, food to microorganisms (biomass) (F/M) ratio, MLSS concentration, volumetric organic loading rate (OLR) and membrane flux. Although it is the most applied method, concurrent change of SRT (or F/M ratio) and MLSS concentration is not a good parameter manipulation method because it causes unnecessary changes in many other parameters such as viscosity, oxygen transfer efficiency and oxygen utilization rate. The method of constant SRT–variable MLSS concentration has similar disadvantages to the method of variable SRT–variable MLSS concentration. The best alternative parameter manipulation method to study membrane fouling is the method of variable SRT–constant MLSS concentration because this method eliminates unnecessary changes in other parameters. In addition, while changing OLR or hydraulic retention time (HRT), contrary to the common application, membrane flux should be kept constant because any change in flux overrides changes in other parameters. Accordingly, required changes in OLR or HRT should be made by adjusting membrane area rather than membrane flux.

scholarly journals Development of a Novel Metalworking Fluid Engineered for Use With Microfiltration Recycling

2006 ◽  
Vol 129 (1) ◽  
pp. 135-142 ◽  
Author(s):  
J. E. Wentz ◽  
S. G. Kapoor ◽  
R. E. DeVor ◽  
N. Rajagopalan
Keyword(s):  
Steady State ◽  
Membrane Fouling ◽  
Cross Flow ◽  
Alumina Membranes ◽  
Steady State Flux ◽  
Metalworking Fluid ◽  
Microscope Imaging ◽  
Microfiltration Membranes ◽  
Electron Microscope Imaging ◽  
Scanning Electron

Membrane microfiltration is a promising technology that has been shown to extend metalworking fluid (MWF) life by eliminating contaminants while allowing the fluid to stay in use. However, the efficacy of this technology is compromised by the clogging of the filter pores in a process known as membrane fouling. In this paper the fouling issue is addressed by the development of a semi-synthetic MWF specifically designed to not foul microfiltration membranes. The composition of the designed MWF is discussed and compared with a commercial MWF. Cross-flow microfiltration fouling tests were carried out in low-pressure, high-velocity conditions on ceramic α-alumina membranes. Several common MWF components are shown not to be factors of membrane fouling on these membranes. The flux of the designed fluid was found to reach an immediate steady state at about twice the value of the steady-state flux of the tested commercial fluid. Scanning electron microscope imaging was used to further evaluate membrane fouling by each fluid. The machining capabilities of the designed fluid were examined in terms of cutting forces and machining temperature.

Sign in / Sign up

Export Citation Format

Share Document