Two sand packs were filled with fine glass beads and quartz sand respectively. The characteristics of crosslinked polymer flowing through the sand packs as well as the influence of shear fracture of porous media on th...Two sand packs were filled with fine glass beads and quartz sand respectively. The characteristics of crosslinked polymer flowing through the sand packs as well as the influence of shear fracture of porous media on the indepth profile modification of the weak gel generated from the crosslinked polymer were investigated. The results indicated that under the dynamic condition crosslinking reaction happened in both sand packs, and the weak gels in these two cases became small gel particles after water flooding. The differences were： the dynamic gelation time in the quartz sand pack was longer than that in the glass bead pack. Residual resistance factor （FRR） caused by the weak gel in the quartz sand pack was smaller than that in the glass bead pack. The weak gel became gel particles after being scoured by subsequent flood water. A weak gel with uniform apparent viscosity and sealing characteristics was generated in every part of the glass bead pack, which could not only move deeply into the sand pack but also seal the high capacity channels again when it reached the deep part. The weak gel performed in-depth profile modification in the glass bead pack, while in the quartz sand pack, the weak gel was concentrated with 100 cm from the entrance of the sand pack. When propelled by the subsequent flood water, the weak gel could move towards the deep part of the sand pack but then became tiny gel particles and could not effectively seal the high capacity channels there. The in-depth profile modification of the weak gel was very weak in the quartz sand pack. It was the shear fracture of porous media that mainly affected the properties and weakened the in-depth profile modification of the weak gel.展开更多
The adsorption properties of a novel gel-type weak acid resin (110-H) for Pb2+ were investigated using chemical methods and IR spectrometry.The optimal adsorption condition of 110-H for Pb2+ is at pH=6.49 in HAc-NaAc ...The adsorption properties of a novel gel-type weak acid resin (110-H) for Pb2+ were investigated using chemical methods and IR spectrometry.The optimal adsorption condition of 110-H for Pb2+ is at pH=6.49 in HAc-NaAc medium and the statically saturated adsorption capacity is 485 mg/g at 298 K.Pb2+ adsorbed on 110-H resin can be eluted with 0.025 mol/L HCl quantificationally.The adsorption rate constants determined under the temperatures of 288,298,308 and 318 K are 2.46×10-5,3.82×10-5,4.46×10-5 and 5.71×10-5 s-1,respectively.The apparent activation energy,Ea,is 18.1 kJ/mol and the thermodynamic parameters of adsorption,ΔH=20.9 kJ/mol,ΔS=161 J/(mol.K) and ΔG298 K =-48.0 kJ/mol,respectively.The adsorption behavior of 110-H resin for Pb2+ accords with the Langmuir isotherm.Infrared spectra show that the oxygen atoms of the functional group of resin coordinate with Pb2+ to form the coordination bands.展开更多
文摘Two sand packs were filled with fine glass beads and quartz sand respectively. The characteristics of crosslinked polymer flowing through the sand packs as well as the influence of shear fracture of porous media on the indepth profile modification of the weak gel generated from the crosslinked polymer were investigated. The results indicated that under the dynamic condition crosslinking reaction happened in both sand packs, and the weak gels in these two cases became small gel particles after water flooding. The differences were： the dynamic gelation time in the quartz sand pack was longer than that in the glass bead pack. Residual resistance factor （FRR） caused by the weak gel in the quartz sand pack was smaller than that in the glass bead pack. The weak gel became gel particles after being scoured by subsequent flood water. A weak gel with uniform apparent viscosity and sealing characteristics was generated in every part of the glass bead pack, which could not only move deeply into the sand pack but also seal the high capacity channels again when it reached the deep part. The weak gel performed in-depth profile modification in the glass bead pack, while in the quartz sand pack, the weak gel was concentrated with 100 cm from the entrance of the sand pack. When propelled by the subsequent flood water, the weak gel could move towards the deep part of the sand pack but then became tiny gel particles and could not effectively seal the high capacity channels there. The in-depth profile modification of the weak gel was very weak in the quartz sand pack. It was the shear fracture of porous media that mainly affected the properties and weakened the in-depth profile modification of the weak gel.
基金Project (Y404279) supported by the Natural Science Foundation of Zhejiang Province, China
文摘The adsorption properties of a novel gel-type weak acid resin (110-H) for Pb2+ were investigated using chemical methods and IR spectrometry.The optimal adsorption condition of 110-H for Pb2+ is at pH=6.49 in HAc-NaAc medium and the statically saturated adsorption capacity is 485 mg/g at 298 K.Pb2+ adsorbed on 110-H resin can be eluted with 0.025 mol/L HCl quantificationally.The adsorption rate constants determined under the temperatures of 288,298,308 and 318 K are 2.46×10-5,3.82×10-5,4.46×10-5 and 5.71×10-5 s-1,respectively.The apparent activation energy,Ea,is 18.1 kJ/mol and the thermodynamic parameters of adsorption,ΔH=20.9 kJ/mol,ΔS=161 J/(mol.K) and ΔG298 K =-48.0 kJ/mol,respectively.The adsorption behavior of 110-H resin for Pb2+ accords with the Langmuir isotherm.Infrared spectra show that the oxygen atoms of the functional group of resin coordinate with Pb2+ to form the coordination bands.
