Screening hydroxyapatite for cadmium and lead immobilization in aqueous solution and contaminated soil: The role of surface area

2017 ◽  
Vol 52 ◽  
pp. 141-150 ◽  
Author(s):  
Hongying Li ◽  
Xisheng Guo ◽  
Xinxin Ye
2021 ◽  
Vol 11 (16) ◽  
pp. 7607
Author(s):  
Souad Boumad ◽  
Antonia Infantes-Molina ◽  
Isabel Barroso-Martín ◽  
Elisa Moretti ◽  
Enrique Rodríguez-Castellón ◽  
...  

This research aims to study the possible improvement of methylene blue (MB) removal from aqueous solution by hybrid adsorbent-catalysts (AdsCats) prepared through the incorporation of activated carbon derived from Luffa cylindrica fibers (LAC) to TiO2 photocatalysts. LAC with a specific surface area of 1170 m2/g was prepared by chemical activation with phosphoric acid at 500 °C. TiO2/LAC composites with 70 and 90 wt.% Degussa P25 titania content were prepared. The materials were characterized by N2 physical adsorption, XRD, FTIR, and XPS. The AdsCats displayed a very good dispersion of TiO2 over LAC, a surface area of close to 200 or 400 m2/g, depending on the composition, and high crystallinity, showing the presence of anatase and rutile phases. MB removal was studied in two different scenarios: under UV-light after reaching adsorption equilibrium, and under UV-light once the liquid effluent and the AdsCats were in contact. The MB removal by LAC has proved to be very efficient, highlighting the predominant role of adsorption over photodegradation. The prepared AdsCats have also been compared with their components. The results showed that TiLAC hybrids have superior photocatalytic performance than P25, showing TiLAC-7/3 90% MB removal with respect to the initial concentration just after 30 min of UV light irradiation for both studied scenarios.


2019 ◽  
Vol 12 (23) ◽  
Author(s):  
Somayeh Sefidgar Shahkolaie ◽  
Mojtaba Baranimotlagh ◽  
Esmael Dordipour ◽  
Farhad Khormali

2016 ◽  
Vol 18 (4) ◽  
pp. 3352-3356 ◽  
Author(s):  
Hoang Minh Ngo ◽  
Phuong Phong Nguyen ◽  
Isabelle Ledoux-Rak

Gold nanoparticles display exceptionally strong β values. We demonstrated that the first hyperpolarizability (β) strongly depends on surface area of gold nanoparticles.


Author(s):  
A. Legrouri

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.


2018 ◽  
Vol 9 (1) ◽  
pp. 79-84
Author(s):  
Vaishali V. Shahare ◽  
Rajni Grover ◽  
Suman Meena

Background: The persistent dioxins/furans has caused a worldwide concern as they influence the human health. Recent research indicates that nonmaterial may prove effective in the degradation of Dioxins/furans. The nanomaterials are very reactive owing to their large surface area to volume ratio and large number of reactive sites. However, nanotechnology applications face both the challenges and the opportunities to influence the area of environmental protection. Objective: i) To study the impact of oil mediated UV-irradiations on the removal of 2,3,7,8-TCDD, 2,3,7,8-TCDF, OCDD and OCDF in simulated soil samples. ii) To compare the conventional treatment methods with the modern available nanotechniques for the removal of selected Dioxins/furans from soil samples. Methods: The present work has investigated an opportunity of the degradation of tetra and octachlorinated dioxins and furans by using oil mediated UV radiations with subsequent extraction of respective dioxins/furans from soils. The results have been compared with the available nanotechniques. Results: The dioxin congeners in the simulated soil sample showed decrease in concentration with the increase in the exposure time and intensity of UV radiations. The dechlorination of PCDD/Fs using palladized iron has been found to be effective. Conclusion: Both the conventional methods and nanotechnology have a dramatic impact on the removal of Dioxins/furans in contaminated soil. However, the nanotechniques are comparatively costlier and despite the relatively high rates of PCDDs dechlorination by Pd/nFe, small fraction of the dioxins are recalcitrant to degradation over considerable exposure times.


2021 ◽  
pp. 105643
Author(s):  
Jose F. Gomes ◽  
Michael Davies ◽  
Peter Smith ◽  
Franca Jones
Keyword(s):  

Author(s):  
Changjian Xie ◽  
Yuhui Ma ◽  
Peng Zhang ◽  
Junzhe Zhang ◽  
Xiaowei Li ◽  
...  

With the increasing environmental application and discharge of nano cerium dioxide (nano-CeO2), it is urgent to fully understand its ecotoxicological effects on the aquatic environment. This study for the first...


2006 ◽  
Vol 72 (1) ◽  
pp. 28-36 ◽  
Author(s):  
A. D'Annibale ◽  
F. Rosetto ◽  
V. Leonardi ◽  
F. Federici ◽  
M. Petruccioli

ABSTRACT Nine fungal strains isolated from an aged and heavily contaminated soil were identified and screened to assess their degradative potential. Among them, Allescheriella sp. strain DABAC 1, Stachybotrys sp. strain DABAC 3, and Phlebia sp. strain DABAC 9 were selected for remediation trials on the basis of Poly R-478 decolorization associated with lignin-modifying enzyme (LME) production. These autochthonous fungi were tested for the abilities to grow under nonsterile conditions and to degrade various aromatic hydrocarbons in the same contaminated soil. After 30 days, fungal colonization was clearly visible and was confirmed by ergosterol determination. In spite of subalkaline pH conditions and the presence of heavy metals, the autochthonous fungi produced laccase and Mn and lignin peroxidases. No LME activities were detected in control microcosms. All of the isolates led to a marked removal of naphthalene, dichloroaniline isomers, o-hydroxybiphenyl, and 1,1′-binaphthalene. Stachybotrys sp. strain DABAC 3 was the most effective isolate due to its ability to partially deplete the predominant contaminants 9,10-anthracenedione and 7H-benz[DE]anthracen-7-one. A release of chloride ions was observed in soil treated with either Allescheriella sp. strain DABAC 1 or Stachybotrys sp. strain DABAC 3, suggesting the occurrence of oxidative dehalogenation. The autochthonous fungi led to a significant decrease in soil toxicity, as assessed by both the Lepidium sativum L. germination test and the Collembola mortality test.


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