Ceramic membrane fouling by dissolved organic matter generated during on-line chemical cleaning with ozone in MBR

2018 ◽  
Vol 146 ◽  
pp. 328-336 ◽  
Author(s):  
Huifang Sun ◽  
Hang Liu ◽  
Siyu Wang ◽  
Fangqin Cheng ◽  
Yu Liu
Membranes ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 122 ◽  
Author(s):  
Lavern Nyamutswa ◽  
Bo Zhu ◽  
Dimuth Navaratna ◽  
Stephen Collins ◽  
Mikel Duke

Adopting an effective strategy to control fouling is a necessary requirement for all membrane processes used in the water/wastewater treatment industry to operate sustainably. The use of ultraviolet (UV) activated photocatalysis has been shown to be effective in mitigating ceramic membrane fouling by natural organic matter. The widely used configuration in which light is directed through the polluted water to the membrane’s active layer suffers from inefficiencies brought about by light absorption by the pollutants and light shielding by the cake layer. To address these limitations, directing light through the substrate, instead of through polluted water, was studied. A UV conducting membrane was prepared by dip coating TiO2 onto a sintered glass substrate. The substrate could successfully conduct UV from a lamp source, unlike a typical alumina substrate. The prepared membrane was applied in the filtration of a humic acid solution as a model compound to study natural organic matter membrane fouling. Directing UV through the substrate showed only a 1 percentage point decline in the effectiveness of the cleaning method over two cleaning events from 72% to 71%, while directing UV over the photocatalytic layer had a 9 percentage point decline from 84% to 75%. Adapting the UV-through-substrate configuration could be more useful in maintaining membrane functionality during humic acid filtration than the current method being used.


2019 ◽  
Vol 149 ◽  
pp. 65-73 ◽  
Author(s):  
Sanghun Park ◽  
Taewoo Nam ◽  
Jeongyeop You ◽  
Eun-Sik Kim ◽  
Ilhwan Choi ◽  
...  

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 545 ◽  
Author(s):  
Rathmalgodage Thejani Nilusha ◽  
Tuo Wang ◽  
Hongyan Wang ◽  
Dawei Yu ◽  
Junya Zhang ◽  
...  

The cost-effective and stable operation of an anaerobic ceramic membrane bioreactor (AnCMBR) depends on operational strategies to minimize membrane fouling. A novel strategy for backwashing, filtration and relaxation was optimized for stable operation of a side stream tubular AnCMBR treating domestic wastewater at the ambient temperature. Two in situ backwashing schemes (once a day at 60 s/day, and twice a day at 60 s × 2/day) maintaining 55 min filtration and 5 min relaxation as a constant were compared. A flux level over 70% of the initial membrane flux was stabilized by in situ permeate backwashing irrespective of its frequency. The in situ backwashing by permeate once a day was better for energy saving, stable membrane filtration and less permeate consumption. Ex situ chemical cleaning after 60 days’ operation was carried out using pure water, sodium hypochlorite (NaOCl), and citric acid as the order. The dominant cake layer was effectively reduced by in situ backwashing, and the major organic foulants were fulvic acid-like substances and humic acid-like substances. Proteobacteria, Firmucutes, Epsilonbacteria and Bacteroides were the major microbes attached to the ceramic membrane fouling layer which were effectively removed by NaOCl.


2009 ◽  
Vol 395 (3) ◽  
pp. 797-807 ◽  
Author(s):  
Gabriel Morales-Cid ◽  
Istvan Gebefugi ◽  
Basem Kanawati ◽  
Mourad Harir ◽  
Norbert Hertkorn ◽  
...  

2009 ◽  
Vol 43 (2) ◽  
pp. 389-394 ◽  
Author(s):  
Cheng-Fang Lin ◽  
Angela Yu-Chen Lin ◽  
Panchangam Sri Chandana ◽  
Chao-Yuan Tsai

2009 ◽  
Vol 60 (6) ◽  
pp. 1385-1392 ◽  
Author(s):  
B. R. H. Peiris ◽  
H. Budman ◽  
C. Moresoli ◽  
R. L. Legge

A method that would allow for fast and reliable measurements of dissolved organic matter (DOM), both at low and high concentration levels would be a valuable tool for online monitoring of DOM. This could have applications in a variety of areas including membrane treatment systems for drinking water applications which is of interest to our group. In this study, the feasibility of using fluorescence spectroscopy for monitoring DOM at very low concentration levels was demonstrated with an emphasis on optimizing the instrument parameters necessary to obtain reproducible fluorescence signals. Signals were acquired using a cuvette or a fibre optic probe assembly, the latter which may have applications for on-line or in-line monitoring. The instrument parameters such as photomultiplier tube (PMT) voltage, scanning rate and slit width were studied in detail to find the optimum parameter settings required. The results showed that larger excitation and emission slit widths were preferred, over larger PMT voltage or lower scanning rates, to obtain reproducible and rapid measurements when measuring very low concentration levels of DOM. However, this approach should be implemented with caution to avoid any reduction of the signal resolution.


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