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

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%.

2013 ◽  
Vol 67 (3) ◽  
pp. 604-611 ◽  
Author(s):  
Nadir Dizge ◽  
Derya Y. Koseoglu-Imer ◽  
Ahmet Karagunduz ◽  
Bulent Keskinler

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.


2011 ◽  
Vol 233-235 ◽  
pp. 680-683
Author(s):  
Shuo Liu ◽  
Yan Ping Liu ◽  
Bao Zhen Wang ◽  
Ji Fu Wang

To alleviate the membrane fouling in membrane bioreactor, a kind of modified diatomite was used as anti-fouling agent to examine the effect on sludge properties in submerged membrane bioreactor for synthetic domestic wastewater treatment. Three submerged membrane bioreactor setups were operated under fixed membrane flux 21.9m3/m2·h, meanwhile, modified diatomite was added into each membrane bioreactor with dosage of 0mg/L, 1000mg/L and 2000mg/L respectively. Sludge particle size, extracellular polymeric substances and molecular weight distribution were characterized as the activated sludge properties in this study. The experiment results showed that with the increase of modified diatomite dosage, the number of sludge particle size less than 10μm was declined, however, the number between 10–20μm was increased correspondingly. Total extracellular polymeric substances and big molecular weight substances were decreased remarkably with modified diatomite addition dosage of 1000mg/L. The results indicated that addition of modified diatomite could effect of sludge properties in submerged membrane bioreactor. Therefore, membrane filtration performance could be improved by modified diatomite adding which alleviate membrane fouling directly.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1068
Author(s):  
Seunghan Ryu ◽  
Sanghun Lee ◽  
Hannah Oh ◽  
Sanghwa Oh ◽  
Minsoo Park ◽  
...  

In this study, paper-mill wastewater was treated using the Submerged Membrane Bioreactor (SMBR) process. In particular, the ozone oxidation treatment process is applied after SMBR to remove the fluorescent whitening agent, which is a trace pollutant and non-biodegradable. Fluorescent whitening agent concentration was indirectly measured by UV scanning and COD concentration. The concentration of COD before SMBR and ozone oxidation was 449.3 mg/L, and the concentration of treated water was 100.3 mg/ℓ. The COD removal efficiency of paper-mill wastewater through SMBR and the ozone oxidation process was about 77.68%. The optimized amount of ozone was required for the removal of the fluorescent whitening agent after SMBR was 95 mg·O3/ℓ calculated by UV scan results. Additionally, the optimized amount of required ozone to remove COD was calculated to 0.126 mg·COD/mg·O3.


2005 ◽  
Vol 67 (3) ◽  
pp. 351-356 ◽  
Author(s):  
Chackrit Nuengjamnong ◽  
Ji Hyang Kweon ◽  
Jinwoo Cho ◽  
Kyu-Hong Ahn ◽  
Chongrak Polprasert

2010 ◽  
Vol 113-116 ◽  
pp. 2057-2061 ◽  
Author(s):  
Zhan Ping Cao ◽  
Jing Li Zhang ◽  
Hong Wei Zhang

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.


2014 ◽  
Vol 955-959 ◽  
pp. 1939-1943
Author(s):  
Chun Hua Zhang ◽  
Xiao Xia Ou ◽  
Feng Jie Zhang

Suspended carriers were added into a submerged membrane bioreactor (SMBR) using polypropylene non-woven fabric (PP NWF) as membrane model to treat synthetic wastewater. The changes of EPSSEPSB and EPS in activated sludge mixing liquid of MBR and in sludge on membrane model surface were researched at different aeration rate. The results showed that adding suspended carriers in MBR can increase the concentration of EPSS and EPSB in activated sludge mixing liquid, but the effect on EPSS and EPSB in the sludge on membrane model surface is related to aeration rate. Adding suspended carriers can increase the concentration of EPSS and EPSB in the sludge on membrane model surface at 0.10m3/h of aeration rate; the concentration of EPSS and EPSB in the sludge with suspended carriers is reduced when aeration rate is increased to 0.25m3/h. The study on the effect of aeration rate on EPS in sludge mixing liquid of MBR and in sludge on membrane model surface showed that an optimized aeration rate exists if suspended carriers are added to control MBR membrane fouling. At the optimized aeration rate, membrane fouling can be mitigated and controled effectively.


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