Equilibrium and Kinetic Studies of the Adsorption of Cr(III) Ions onto Amberlite XAD-8 Impregnated with Di-(2-ethylhexyl) Phosphoric Acid (DEHPA) by Mihaela Ciopec, Corneliu Mircea Davidescu, Adina Negrea, Cornelia Muntean, Adriana Popa, Petru Negrea, Lavinia Lupa

“…The values of ΔH 0 and ΔG 0 obtained showed that the adsorption process was endothermic and spontaneous. The adsorption activation energy also showed that the process was endothermic.…”
Get full text

Kinetics, Thermodynamics and Equilibrium Studies for Gold Recovery from Diluted Waste Solution by Adina Negrea, Sylwia Ronka, Mihaela Ciopec, Narcis Duteanu, Petru Negrea, Maria Mihailescu

“…On the basis of the thermodynamic study, it was concluded that gold recovery on coP-TEDMA/EGDMA is a spontaneous and endothermic process.…”
Get full text

Kinetics and Thermodynamics Studies for Cadmium (II) Adsorption onto Functionalized Chitosan with Hexa-Decyl-Trimethyl-Ammonium Chloride by Cristina Ardean, Mihaela Ciopec, Corneliu Mircea Davidescu, Petru Negrea, Raluca Voda

“…Likewise, we evaluated the values of thermodynamic parameters which indicate that the studied process is an endothermic and spontaneous one, being a physical adsorption. …”
Get full text

A New Perspective on Adsorbent Materials Based Impregnated MgSiO₃ with Crown Ethers for Palladium Recovery by Mihaela Ciopec, Oana Grad, Adina Negrea, Narcis Duteanu, Petru Negrea, Cristina Paul, Catalin Ianăși, Giannin Mosoarca, Cosmin Vancea

“…Thermodynamic studies highlight that the adsorption of Pd(II) on the two studied materials are spontaneous and endothermic processes. The positive values of the entropy (ΔS⁰) suggest that the studied adsorption processes show a higher disorder at the liquid/solid interface. …”
Get full text

Vanadium (V) Adsorption from Aqueous Solutions Using Xerogel on the Basis of Silica and Iron Oxide Matrix by Florin Matusoiu, Adina Negrea, Mihaela Ciopec, Narcis Duteanu, Petru Negrea, Paula Ianasi, Cătălin Ianasi

“…In our case, the process is physical, endothermic, spontaneous, and takes place at the interface of SiO₂Fe_xO_y with V₂O₅. …”
Get full text

Indium Recovery by Adsorption on MgFe₂O₄ Adsorbents by Loredana Ciocărlie, Adina Negrea, Mihaela Ciopec, Narcis Duteanu, Petru Negrea, Paula Ianasi, Catalin Ianasi, Nicoleta Sorina Nemes

“…From kinetic and thermodynamic studies was proved that the studied adsorption process is homogeneous, spontaneous, endothermic and temperature dependent. Based on Weber and Morris model, we can conclude that the In (III) ions takes place at the MgFe₂O₄/In (III) solution–material interface.…”
Get full text

Arsenic Removal Using Unconventional Material with Iron Content: Batch Adsorption and Column Study by Cosmin Vancea, Georgiana Mladin, Mihaela Ciopec, Adina Negrea, Narcis Duteanu, Petru Negrea, Giannin Mosoarca, Catalin Ianasi

“…It was found that the adsorption process is spontaneous, endothermic, and of a physical nature. In the batch adsorption studies, the maximum removal percentage was 80.4% after 90 min, and in a dynamic regime in the fixed-bed column, the efficiency was 99.99% at a sludge:sand = 1:1 ratio for 380 min for a volume of water with arsenic of ~3000 mL. …”
Get full text

Platinum (IV) Recovery from Waste Solutions by Adsorption onto Dibenzo-30-crown-10 Ether Immobilized on Amberlite XAD7 Resin–Factorial Design Analysis by Oana Buriac, Mihaela Ciopec, Narcis Duţeanu, Adina Negrea, Petru Negrea, Ioan Grozav

“…Thermodynamic parameters (Δ<i>G</i>°, Δ<i>H</i>°, Δ<i>S</i>°) showed that the adsorption process was endothermic and spontaneous. After adsorption, metallic platinum was recovered from the exhausted adsorbent material by thermal treatment. …”
Get full text

Adsorbent Material Based on Carbon Black and Bismuth with Tunable Properties for Gold Recovery by Cătălin Ianăşi, Paula Svera (m. Ianăşi), Alexandru Popa, Radu Lazău, Adina Negrea, Petru Negrea, Narcis Duteanu, Mihaela Ciopec, Nicoleta-Sorina Nemes

“…Thermodynamic studies proved that the gold adsorption on BCb/CB material is a spontaneous and endothermal process. The results indicate a total adsorption capacity of 13.1 mg Au(III)/g material. …”
Get full text