Microbial growth and degradation kinetics of perchlorate by Proteus sp. LMNCRE in a batch reactor system

Author(s):  
J.R. Anoop Raj ◽  
L. Muruganandam
2011 ◽  
Vol 356-360 ◽  
pp. 186-189
Author(s):  
Zong Lian She ◽  
Tian Xie ◽  
Lei Lei Li ◽  
Ying Jie Zhu ◽  
Gai Feng Tang ◽  
...  

The degradation kinetics of 2,4-dinitrophenol (2,4-DNP) and 2,6-dinitrophenol (2,6-DNP) were investigated in this paper. The degradation kinetics experiments were conducted in sequencing batch reactor (SBR) and the degradation model was analyzed by nonlinear regression to estimate parameters including the degradation rate Kmax, half saturation constant KSand the inhibition constant KIin the Andrews inhibition equation. The degradation inhibition in the condition of 2,4-DNP as solo substrate is more serious than that of the situation with glucose as co-substrate and Kmaxdecreases with the increase of inflow 2,4-DNP concentration. As for 2,6-DNP, Kmaxgets maximum value is 0.019 mg/(mgSS×d) at the inflow concentration is 20mg/L. KSincreases with the increasing of inflow 2,6-DNP concentration but there is no regularity for KI.


2009 ◽  
Vol 36 (3) ◽  
pp. 550-568 ◽  
Author(s):  
M.I.H. Bhuiyan ◽  
D.S. Mavinic ◽  
R.D. Beckie

Dissolution kinetics of struvite are important for optimizing intentional struvite crystallization, as well as for ensuring the efficient use of the crystallized products. Dissolution experiments were carried out for struvite pellets grown in a pilot-scale fluidized bed reactor. To determine the kinetics and mechanism of the dissolution process in a batch reactor system, two different theoretical models were tested. The experimental values were found to fit well with both models. In a mixed flow-through reactor system, the constituents release became stoichiometric when the input solution had an alkaline pH. The dissolution rates for struvite pellets were found to decrease with increasing pH due to proton promoted dissolution. After a transition from around 7.5 to 8, the rate of dissolution increased with the increase in pH, because of the hydroxyl promoted dissolution.


Author(s):  
Zafirah Mahyun ◽  
Noor Fazliani Shoparwe ◽  
Ahmad Zuhairi Abdullah ◽  
Abdul Latif Ahmad ◽  
Mardawani Mohamad ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1597
Author(s):  
Iman Jafari ◽  
Mohamadreza Shakiba ◽  
Fatemeh Khosravi ◽  
Seeram Ramakrishna ◽  
Ehsan Abasi ◽  
...  

The incorporation of nanofillers such as graphene into polymers has shown significant improvements in mechanical characteristics, thermal stability, and conductivity of resulting polymeric nanocomposites. To this aim, the influence of incorporation of graphene nanosheets into ultra-high molecular weight polyethylene (UHMWPE) on the thermal behavior and degradation kinetics of UHMWPE/graphene nanocomposites was investigated. Scanning electron microscopy (SEM) analysis revealed that graphene nanosheets were uniformly spread throughout the UHMWPE’s molecular chains. X-Ray Diffraction (XRD) data posited that the morphology of dispersed graphene sheets in UHMWPE was exfoliated. Non-isothermal differential scanning calorimetry (DSC) studies identified a more pronounced increase in melting temperatures and latent heat of fusions in nanocomposites compared to UHMWPE at lower concentrations of graphene. Thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG) revealed that UHMWPE’s thermal stability has been improved via incorporating graphene nanosheets. Further, degradation kinetics of neat polymer and nanocomposites have been modeled using equations such as Friedman, Ozawa–Flynn–Wall (OFW), Kissinger, and Augis and Bennett’s. The "Model-Fitting Method” showed that the auto-catalytic nth-order mechanism provided a highly consistent and appropriate fit to describe the degradation mechanism of UHMWPE and its graphene nanocomposites. In addition, the calculated activation energy (Ea) of thermal degradation was enhanced by an increase in graphene concentration up to 2.1 wt.%, followed by a decrease in higher graphene content.


2021 ◽  
pp. 100757
Author(s):  
Akshay Sonawane ◽  
O.P. Chauhan ◽  
Shubhankar D. Semwal ◽  
A.D. Semwal

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2872
Author(s):  
Seyed Mohamad Reza Paran ◽  
Ghasem Naderi ◽  
Elnaz Movahedifar ◽  
Maryam Jouyandeh ◽  
Krzysztof Formela ◽  
...  

The effect of several concentrations of carboxylated nitrile butadiene rubber (XNBR) functionalized halloysite nanotubes (XHNTs) on the vulcanization and degradation kinetics of XNBR/epoxy compounds were evaluated using experimental and theoretical methods. The isothermal vulcanization kinetics were studied at various temperatures by rheometry and differential scanning calorimetry (DSC). The results obtained indicated that the nth order model could not accurately predict the curing performance. However, the autocatalytic approach can be used to estimate the vulcanization reaction mechanism of XNBR/epoxy/XHNTs nanocomposites. The kinetic parameters related to the degradation of XNBR/epoxy/XHNTs nanocomposites were also assessed using thermogravimetric analysis (TGA). TGA measurements suggested that the grafted nanotubes strongly enhanced the thermal stability of the nanocomposite.


Materials ◽  
2017 ◽  
Vol 10 (11) ◽  
pp. 1246 ◽  
Author(s):  
Samson M. Mohomane ◽  
Tshwafo E. Motaung ◽  
Neerish Revaprasadu

2016 ◽  
Vol 34 (10) ◽  
pp. 1175-1184 ◽  
Author(s):  
Giovana Bonat Celli ◽  
Rojin Dibazar ◽  
Amyl Ghanem ◽  
Marianne Su-Ling Brooks

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