Naturally propped fractures caused by quartz cementation preserve oil reservoirs in basement rocks

MB is in receipt of a postgraduate studentship from PTDF (Nigeria). Skilled technical support was provided by M. Baron and J. Still. Two reviewers made valuable criticisms that improved the paper.Peer reviewedPostprin

Study on laccase stability in ionic liquides

W niniejszej pracy zbadano aktywność lakazy w obecności trzech cieczy jonowych o różnej hydrofobowości. Stwierdzono, że wpływ cieczy jonowej jest silnie zależny od jej struktury - ciecze hydrofilowe silnie inaktywują enzym, podczas gdy obecność hydrofobowego tetrafluoro-boranu l-metylo-3-butyloimidazoliowego w stężeniu poniżej 10% nie powoduje znaczącego spadku aktywności.The activity of laccase in the presence of ionic liquids (ILs) has been examined. Three ILs of different hydrophobicity have been tested. The results obtained clearly show that effect of IL strongly depends on its chemical nature - hydrophilic compounds inactivate vast majority of enzyme, while hydrophobic l-methyl-3-butylimidazolium tetrafluoro-borate at the concentration up to 10% does not cause loss of laccase activity

Extraction of organic impurities using 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF 6

Extraction of several chloro compounds from water has been examined. As the extracting liquid the 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6], which is common hydrophobic ionic liquid, was used. Additionally, extraction of selected chlorinated compounds from tert-butylmethylether (MTBE) was investigated. The obtained results show the usefulness of [BMIM][PF6] to remove the organic impurities from water, particularly at the concentration range inappropriate for biological purification plants

Use of fly ash and fly ash agglomerates for As(III) adsorption from aqueous solution

The objective of the present study is to assess the efficiency of fly ash and fly ash agglomerates to remove arsenic(III) from aqueous solution. The maximum static uptakes were achieved to be 13.5 and 5.7 mgAs(III)/adsorbent for nonagglomerated material and agglomerated one, respectively. Isotherm studies showed good fit with the Langmuir (fly ash) and the Freundlich (fly ash agglomerates) isotherm models. Kinetic studies indicated that the sorption of arsenic on fly ash and its agglomerates follows the pseudo-second-order (PSO) chemisorption model (R2 = 0.999). Thermodynamic parameters revealed an endothermic nature of As(III) adsorption on such adsorbents. The adsorption results confirmed that fly ash and its agglomerates can be used for As(III) removal from aqueous solutions. Fly ash can adsorb more arsenic(III) than agglomerates, which are easier to use, because this material is less dusty and easier to separate from solution

Application of fly ash agglomerates in the sorption of arsenic

The scope of this contribution was to investigate in detail an application of fly ash adsorbent for the removal of arsenite ions from a dilute solution. The experiments have been carried out using fly ash from black coal burning power plant "Siersza" and brown coal burning power plant "Turów" (Poland), which was wetted, then mixed and tumbled in the granulator with a small amount of cement to increase the mechanical strength of agglomerates. The measurements of arsenic adsorption from the aqueous solution were carried out in the flask (with shaking), as well as in the column (with circulation), in order to compare two different methods of contacting waste with adsorbent. The adsorption isotherms of arsenic were determined for granulated material, using the Freundlich model. Kinetics studies indicated that the sorption follows a pseudo-first-order (PFO) model (Lagergren) and the Elovich-type model

End-to-end self-assembly of gold nanorods in isopropanol solution: experimental and theoretical studies

International audienc

Use of fly ash and fly ash agglomerates for As(III) adsorption from aqueous solution

The objective of the present study is to assess the efficiency of fly ash and fly ash agglomerates to remove arsenic(III) from aqueous solution. The maximum static uptakes were achieved to be 13.5 and 5.7 mgAs(III)/adsorbent for nonagglomerated material and agglomerated one, respectively. Isotherm studies showed good fit with the Langmuir (fly ash) and the Freundlich (fly ash agglomerates) isotherm models. Kinetic studies indicated that the sorption of arsenic on fly ash and its agglomerates follows the pseudo-second-order (PSO) chemisorption model (R2 = 0.999). Thermodynamic parameters revealed an endothermic nature of As(III) adsorption on such adsorbents. The adsorption results confirmed that fly ash and its agglomerates can be used for As(III) removal from aqueous solutions. Fly ash can adsorb more arsenic(III) than agglomerates, which are easier to use, because this material is less dusty and easier to separate from solution

Sorption properties of fly ash from coal burning

Celem niniejszej pracy było zbadanie zdolności sorpcyjnych popiołu po spalaniu węgla brunatnego pod kątem adsorpcji arsenu (III). Uzyskane wyniki wskazują na znaczną pojemność sorpcyjną popiołu lotnego względem As(III) (33 mg/g), porównywalną do otrzymywanej na żywicach jonowymiennych. Dane doświadczalne dobrze opisuje izoterma Langmuira, a proces adsorpcji kontrolowany jest reakcją chemiczną pseudo drugiego rzędu (model PSO).The aim of work was to examine sorption of As(III) species, using fly ash from lignite burning. The results obtained show that the sorption capacity of fly ash (33 mg/g) is comparable to commercial sorbent. Experimental data can be described by means ofLangmuir isotherm. Adsorption process obeys the pseudo-second order (PSO) kinetics

Application of fly ash agglomerates in the sorption of arsenic

The scope of this contribution was to investigate in detail an application of fly ash adsorbent for the removal of arsenite ions from a dilute solution. The experiments have been carried out using fly ash from black coal burning power plant "Siersza" and brown coal burning power plant "Turów" (Poland), which was wetted, then mixed and tumbled in the granulator with a small amount of cement to increase the mechanical strength of agglomerates. The measurements of arsenic adsorption from the aqueous solution were carried out in the flask (with shaking), as well as in the column (with circulation), in order to compare two different methods of contacting waste with adsorbent. The adsorption isotherms of arsenic were determined for granulated material, using the Freundlich model. Kinetics studies indicated that the sorption follows a pseudo-first-order (PFO) model (Lagergren) and the Elovich-type model