http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Khalid, Saira,Han, Jong-In,Hashmi, Imran,Hasnain, Ghalib,Ahmed, Muhammad Ajaz,Khan, Sher Jamal,Arshad, Muhammad Elsevier 2018 Science of the Total Environment Vol.631 No.-
<P><B>Abstract</B></P> <P>Bacterial cell immobilization offer considerable advantages over traditional biotreatment systems using free cells. Calcium alginate matrix usually used for bacterial immobilization is susceptible to biodegradation in harsh environment. Current study aimed to produce and characterize stable macrocapsules (MCs) of Chlorpyrifos (CP) degrading bacterial consortium using biocompatible calcium alginate matrix coupled with environmentally stable polysulfone. In current study bacterial consortium capable of CP biodegradation was immobilized using calcium alginate in a form of microcapsule (MC) reinforced by being coated with a synthetic polymer polysulfone (PSf) through phase inversion. Consortium comprised of five bacterial strains was immobilized using optimized concentration of sodium alginate (2.5gL<SUP>−1</SUP>), calcium chloride (6gL<SUP>−1</SUP>), biomass (600mgL<SUP>−1</SUP>) and polysulfone (10gL<SUP>−1</SUP>). It has been observed that MCs have high thermal, pH and chemical stability than CAMs. In synthetic media complete biodegradation of CP (100–600mgL<SUP>−1</SUP>) was achieved using macrocapsules (MCs) within 18h. CAMs could be reused effectively only upto 5cycles, contrary to this MCs could be used 13 times to achieve more than >96% CP degradation. Shelf life and reusability studies conducted for MCs indicated unaltered biomass retention and CP biodegradation activity (95%) over 16weeks of storage. MCs achieved complete biodegradation of CP (536mgL<SUP>−1</SUP>) in real industrial wastewater and reused several times effectively. Metabolites (3,5,6-trichloro-2-pyridinol (TCP), 3,5,6-trichloro-2-methoxypyridine (TMP) and diethyl-thiophosphate (DETP) were traced using GC–MS and possible metabolic pathway was constructed. Study indicated MCs could be used for cleanup of CP contaminated wastewater repeatedly, safely, efficiently for a longer period of time.</P> <P><B>Highlights</B></P> <P> <UL> <LI> MCs were more tolerant to temperature, pH and chemically harsh environment than CAMs. </LI> <LI> MCs can be used for complete biodegradation of CP upto 600mgL<SUP>−1</SUP>. </LI> <LI> CAMs can be reused for 5cycles only whereas MCs could be reused for 13 times. </LI> <LI> MCs have shelf life upto 16weeks with unaltered cell retention and CP biodegradation activity. </LI> <LI> MCs have potential to protect cells from shock loads of metal ions and organic solvents. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Sidra Khalid,Saira Riaz,Samia Naeem,Aseya Akbar,S. Sajjad Hussain,YB Xu,Shahzad Naseem 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.103 No.-
Production of single-phase materials with multifunctional properties is still a challenge faced by materialscientists. In addition, obtaining high spin polarization efficiency in the materials that exhibit multifunctionalproperties is a big issue. A novel approach is suggested in this work for obtaining multifunctionalityand spin polarization in the same material. This approach has combined the effect of microwave radiationsand aluminum (Al) doping in iron oxide thin films during synthesis. Combined effect of microwaveradiations and Al doping results in controlling / tuning the structural transitions in iron oxide thin films. Pristine and 2–10 wt% Al doped iron oxide thin films are prepared and studied in detail. Raman analysisshows that 2 and 4 wt% Al concentration results in c-Fe2O3 + Fe3O4 phase with 71.3% and 64.5% of c-Fe2O3content, respectively. XRD and Raman analyses confirm the transition from c-Fe2O3 to Fe3O4 thin films atAl concentrations of 6–10 wt%. Structural transformation shows that microwave radiations catalyzes thatAl3+ions to occupy the vacancies on B sites of iron oxide thus, lead to the formation of Fe3O4. Observationof Verwey transition ~ 126 K also supports the transition in phases of iron oxide with increase in saturationmagnetization from 251.3emu/cm3 (pristine films) to 405.6emu/cm3 (8 wt% Al concentration). Highdielectric constant of ~ 135.5 (log f = 5.0) is observed for 8 wt% Al concentration. Conductivity anddetailed impedance & modulus analyses depict Mott’s hopping phenomenon along with presence of differentrelaxation times. Coupling between magnetic and dielectric properties is observed at room temperature. Magnetoresistance curves indicate spin polarization efficiency of ~24%.
Optimization of twin gear-based pretreatment of rice straw for bioethanol production
Ahmed, Muhammad Ajaz,Rehman, Muhammd Saif Ur,Terá,n-Hilares, Ruly,Khalid, Saira,Han, Jong-In Elsevier 2017 Energy conversion and management Vol.141 No.-
<P><B>Abstract</B></P> <P>A laboratory twin-gear reactor (TGR) was investigated as a new means for the pretreatment of high solid lignocelluloses. Response surface methodology based on Box Behnken Design was used to optimize the enzymatic digestibility with respect to the pretreatment process variables: temperature of 50–90°C, NaOH concentration of 2–6% and no. of cycles of 30–60. The results revealed that the TGR-based pretreatment led to the significant structural alterations through increases in pore size, pore volume, cellulose crystallinity and surface area. SEM images also confirmed the surface modifications in the pretreated rice straw. A response surface quadratic model predicted 90% of the enzymatic digestibility, and it was confirmed experimentally and through the analysis of variance (ANOVA) as well. The TGR extrusion proved to be an effective means for exceedingly high solids lignocellulose.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Twin gear reactor is a continuous high solids pretreatment reactor. </LI> <LI> RSM was applied to optimize twin gear pretreatment for enzymatic digestibility. </LI> <LI> 89% enzymatic digestibility was achieved under optimum conditions. </LI> <LI> Thermomechanical pretreatment altered the structural features of rice straw. </LI> </UL> </P>