scholarly journals Optimal Water Backwashing Condition in Combined Water Treatment of Alumina Microfiltration and PP Beads

Membranes ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 92
Author(s):  
Hyungmin Cho ◽  
Gihoon Yoon ◽  
Minjae Kim ◽  
Jin Yong Park

Membrane fouling is a dominant limit of the membrane separation process. In this research, the optimal water backwashing to solve the membrane fouling problem was investigated in the combined water treatment process of alumina MF and pure polypropylene (PP) beads. Additionally, the influence of membrane shape (tubular or seven channel) was examined, depending on the water backwashing period. The optimal backwashing time (BT) could be 20 s in the combined water treatment process, because of the highest total treated volume (VT) in our BT 6–30 s conditions. The optimal backwashing period (BP) could be 6 min, because of the minimum membrane fouling and the maximum VT in the combined process of tubular alumina MF and PP beads. The resistance of reversible membrane fouling (Rrf) showed a major resistance of total membrane fouling, and that of irreversible membrane fouling (Rif) was a minor one, in the combined process using tubular or seven channel MF. The Rif showed a decreasing trend obviously, as decreasing BT from NBW to 2 min for seven channel MF. It means that the more frequent water backwashing could be more effective to control the membrane fouling, especially irreversible fouling, for seven channel membranes than tubular membranes.

Membranes ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 3 ◽  
Author(s):  
Sungju Hwang ◽  
Yooju Lee ◽  
Jin Yong Park

Photooxidation oxidizes most organic compounds by mineralizing them to small inorganic molecules. In this study, the effects of dissolved organic matter (DOM), pH, and polypropylene (PP) beads concentration on membrane fouling were investigated in a hybrid water treatment process consisting of seven-channel alumina microfiltration (pore size 1.0 μm) and pure PP beads water backwashing with UV irradiation for photooxidation. The synthetic feed was prepared with humic acid and kaolin and flowed inside the microfiltration (MF) membrane. The permeate contacted the PP beads fluidized in the gap of the membrane and module with outside UV irradiation. Membrane fouling resistance (Rf) increased dramatically with an increase in the concentration of humic acid (HA) from 6 mg/L to 8 mg/L. The treatment efficiency of DOM increased dramatically, from 14.3% to 49.7%, with an increase in the concentration of HA. The Rf decreased with an increase of PP beads concentration. However, maximum permeate volume (VT) was acquired at 5 g/L of PP beads. The maximal treatment efficiency of DOM was 51.3% at 40 g/L of PP beads. The Rf increased with an increase in the pH of feed, and the maximum VT was acquired at a pH of 5. The maximal treatment efficiency of DOM was 52.5% at pH 9.


2011 ◽  
Vol 281 ◽  
pp. 40-44 ◽  
Author(s):  
Jian Kun Zhang

According to the water quality characteristics, micro-polluted source water treatment by ozone combined processes. The results show that the average removal efficiencies of algae, CODMn, NH4+-N, turbidity, chromaticity by bio-pretreatment filter are 72.0%, 14.5%, 80.5%, 58.6% ,26.0%, respectively; while the whole average removal efficiencies by pre-ozonation tank following bio-pretreatment filter had increased at the different dosages of ozone, such as algae 12.0%, CODMn 19.5% ,NH4+-N 7.5%, turbidity 10.9%, chromaticity 34.5%, respectively; and the optimal dosages of ozone are between 0.7 and 1.5mg/L. Furthermore, compared with the conventional water treatment process, all kinds of combined water treatment processes are better than the conventional one, of which the combined process Ⅲ with granular activated carbon (GAC) adsorption tank is obviously the best, all the average removal efficiencies of algae, CODMn, NH4+-N, turbidity, chromaticity can reach 82%, while whose operation expenditure is higher than any others, so it should be considered comprehensively in the practice.


2016 ◽  
Vol 15 (8) ◽  
pp. 1867-1872
Author(s):  
Florina Fabian ◽  
Silvia Fiore ◽  
Giuseppe Genon ◽  
Deborah Panepinto ◽  
Valentin Nedeff ◽  
...  

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 369
Author(s):  
Shengji Xia ◽  
Xinran Zhang ◽  
Yuanchen Zhao ◽  
Fibor J. Tan ◽  
Pan Li ◽  
...  

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.


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