Roles of membrane–foulant and inter/intrafoulant species interaction forces in combined fouling of an ultrafiltration membrane

2019 ◽  
Vol 652 ◽  
pp. 19-26 ◽  
Author(s):  
Baiwen Ma ◽  
Gongzheng Wu ◽  
Wenjiang Li ◽  
Rui Miao ◽  
Xingfei Li ◽  
...  
2015 ◽  
Vol 30 (2) ◽  
pp. 171 ◽  
Author(s):  
CHEN Tao-Tao ◽  
LI Dan ◽  
JING Wen-Heng ◽  
FAN Yi-Qun ◽  
XING Wei-Hong

1996 ◽  
Vol 34 (9) ◽  
pp. 157-164 ◽  
Author(s):  
Kim C.-H. ◽  
M. Hosomi ◽  
A. Murakami ◽  
M. Okada

Effects of clay on fouling due to organic substances and clay were evaluated by model fouling materials and kaolin. Model fouling materials selected were protein, polysaccharide, fulvic acid, humic acid and algogenic matter (EOM:ectracellular organic matter, microbial decomposition products) and kaolin was selected as the clay material. Polysulfone membrane (MWCO(Molecular Weight Cut-Off) 10,000, 50,000 and 200,000) was used as an ultrafiltration membrane. In particular, the flux measurement of solutions containing algogenic matter used an ultrafiltration membrane of MWCO 50,000. The flux of protein and polysaccharide with coexistence of kaolin increased in the case of the ratio of MW/MWCO being greater than one, but did not increase in the case of the MW/MWCO ratio being below one. In contrast, the flux of fulvic acid and humic acid with coextence of kaolin decreased regardless of the ratio of MW/MWCO. The addition of dispersion agent and coagulant in the organic substances and kaolin mixture solution changed the size distribution of kaolin, and resulted in a change of the flux. EOM and microbial decomposition products decreased with the increase of the fraction of organic matter having molecular weight more than MWCO of membrane. The flux of the algogenic organic matter with coexistence of kaolin decreased with the increase of the amount of kaolin. It was suggested that the decline of the flux with coexistence of kaolin was due to the change of the resistance of the kaolin cake layer corresponding to the change in kaolin size distribution with charge.


1998 ◽  
Vol 38 (4-5) ◽  
pp. 513-520 ◽  
Author(s):  
O. Mizuno ◽  
H. Takagi ◽  
T. Noike

The biological sulfate removal in the acidogenic bioreactor with an ultrafiltration membrane system was investigated at 35°C. Sucrose was used as the sole organic substrate. The sulfate concentration in the substrate ranged from 0 to 600mgS·1−1. The chemostat reactor was operated to compare with the membrane bioreactor. The fouling phenomenon caused by FeS precipitate was observed at higher concentration of sulfate. However, it was possible to continuously operate the membrane bioreactor by cleaning the membrane. The efficiency of sulfate removal by sulfate reduction reached about 100% in the membrane bioreactor, and 55 to 87% of sulfide was removed from the permeate by the membrane filtration. The composition of the metabolite was remarkably changed by the change in sulfate concentration. When the sulfate concentration increased, acetate and 2-proponol significantly increased while n-butyrate and 3-pentanol decreased. The sulfate-reducing bacteria play the role as acetogenic bacteria consuming volatile fatty acids and alcohols as electron donors under sulfate-rich conditions. The results show that the acidogenesis and sulfate reduction simultaneously proceed in the membrane bioreactor.


2021 ◽  
Vol 270 ◽  
pp. 118819
Author(s):  
Nur Azizah Johari ◽  
Norhaniza Yusof ◽  
Woei Jye Lau ◽  
Norfadhilatuladha Abdullah ◽  
Wan Norharyati Wan Salleh ◽  
...  

2021 ◽  
Vol 1764 (1) ◽  
pp. 012156
Author(s):  
E. Putri ◽  
D. Sidabutar ◽  
N.A. Putri ◽  
S. Sakinah ◽  
F.A. Nugroho ◽  
...  

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 870
Author(s):  
Md Rasedul Islam ◽  
Md Assad-Uz-Zaman ◽  
Brahim Brahmi ◽  
Yassine Bouteraa ◽  
Inga Wang ◽  
...  

The design of an upper limb rehabilitation robot for post-stroke patients is considered a benchmark problem regarding improving functionality and ensuring better human–robot interaction (HRI). Existing upper limb robots perform either joint-based exercises (exoskeleton-type functionality) or end-point exercises (end-effector-type functionality). Patients may need both kinds of exercises, depending on the type, level, and degree of impairments. This work focused on designing and developing a seven-degrees-of-freedom (DoFs) upper-limb rehabilitation exoskeleton called ‘u-Rob’ that functions as both exoskeleton and end-effector types device. Furthermore, HRI can be improved by monitoring the interaction forces between the robot and the wearer. Existing upper limb robots lack the ability to monitor interaction forces during passive rehabilitation exercises; measuring upper arm forces is also absent in the existing devices. This research work aimed to develop an innovative sensorized upper arm cuff to measure the wearer’s interaction forces in the upper arm. A PID control technique was implemented for both joint-based and end-point exercises. The experimental results validated both types of functionality of the developed robot.


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