Due to its extensive use in shale gas exploration and development,oil-based drilling fluids generate large amounts of oil-bearing drill cuttings during the drilling process.The large amount of oil-bearing drill cuttin...Due to its extensive use in shale gas exploration and development,oil-based drilling fluids generate large amounts of oil-bearing drill cuttings during the drilling process.The large amount of oil-bearing drill cuttings generated during the drilling process can lead to serious secondary contamination.In this study,a wetting agent FSC-6 with good hydrophobic and oleophobic properties was synthesized to construct an efficient oil removal system.For the first time,the mechanism of this system was analyzed by using the theory of adhesion function,interfacial tension and wettability.At the same time,a combined acoustic-chemical treatment process was applied to the wastewater and slag generated after the cleaning of the oil-bearing drill cuttings.The experimental results show that the application of this pollution-free technology can effectively solve the environmental pollution and resource recovery problems of oil-bearing drill cuttings.It meets the standard of drilling chips with oil content less than 2%in SY/T7422-2018“Oil-based drilling fluid drilling chips treatment system for oil and gas drilling equipment”.展开更多
To deeply clean oily wastewater,molecular sieve residues(MSRs)were sufficiently recycled and utilized due to their high specific surface area,porous structure,and outstanding adsorption property.Molding MSRs(MMSRs)wer...To deeply clean oily wastewater,molecular sieve residues(MSRs)were sufficiently recycled and utilized due to their high specific surface area,porous structure,and outstanding adsorption property.Molding MSRs(MMSRs)were prepared by adding additives(starch,citric acid,and soluble glass)to MSRs and were then filled into a fixed bed for adsorbing and separating the oil in wastewater.Sodium dodecylbenzenesulfonate was used to modify the MMSRs,and their adsorption property was also investigated.In addition,the MSRs were characterized by scanning electron microscopy,energy-dispersive X-ray spectroscopy,Brunauer–Emmett–Teller analysis,and Fourier transform infrared spectroscopy.The results indicated that MMSRs satisfied the filling requirement of fixed bed,and their dynamic adsorption capacity could reach 0.1854 mg g^?1.Furthermore,the static adsorption capacity of MMSRs achieved 1.7346 mg g^?1 in the optimum conditions,and the oil adsorption performance of modified MMSRs was further enhanced.Therefore,this work suggests that MSRs are promising alternatives in cleaning oily wastewater.展开更多
The integration of the photocatalytic effect into solar steam is highly desirable for addressing freshwater shortages and water pollution.Here,a ternary film structure for the adsorption and photothermal and photocata...The integration of the photocatalytic effect into solar steam is highly desirable for addressing freshwater shortages and water pollution.Here,a ternary film structure for the adsorption and photothermal and photocatalytic treatment of wastewater was designed by combining the technique of self-assembled carbon nano paper with a nitrogen composite titanium dioxide(N-TiO_(2))deposited on the surface of carbon nanotubes(CNT)using polyvinylidene fluoride(PVDF)as a substrate.The photogeneration of reactive oxygen species can be promoted by rapid oxygen diffusion at the three-phase interface,whereas the interfacial photothermal effect promotes subsequent free radical reactions for the degradation of rhodamine B(93%).The freshwater evaporation rate is 1.35 kg·m^(-2)·h^(-1)and the solar-to-water evaporation efficiency is 94%.Importantly,the N-TiO_(2)/CNT/PVDF(N-TCP)film not only effectively resists mechanical damage from the environment and maintains structural integrity,but can also be made into a large film for outdoor experiments in a large solar energy conversion device to collect fresh water from polluted water and degrade organic dyes in source water simultaneously,opening the way for applications in energy conversion and storage.展开更多
Membrane fouling is an obstacle impeding the wide applications of ceramic membranes and organics are responsible for most of the membrane fouling issues in wastewater treatment.In this study,Fenton cleaning strategy w...Membrane fouling is an obstacle impeding the wide applications of ceramic membranes and organics are responsible for most of the membrane fouling issues in wastewater treatment.In this study,Fenton cleaning strategy was firstly proposed to clean ceramic membrane fouling in wastewater treatment.Fe2+ efficiently catalyzed fouling cleaning with H2O2 (1.5%) to recover the filterability of ceramic membrane.The maximum ΔTMP recovery (over 99%) was achieved at an optimal Fe2+ dosage of 124 mg/L after 6 hr of immersion cleaning.The total residual membrane fouling resistance decreased gradually from this optimum value as the Fe2+ dosage increased above 124 mg/L.The residual hydraulically reversible fouling resistance accounted for most of the membrane fouling and was basically removed (≤3.0 × 109 m-1) when Fe2+ dosages higher than 124 mg/L were used.The foulants responsible for the formation of a residual hydraulically reversible fouling layer (DOC (dissolved organic carbon),proteins,polysaccharides,EEM (fluorescence excitationemission matrix spectra),SS (suspended solids),and VSS (volatile suspended solids)) were gradually removed as the Fe2+ dosage increased.These residual organic foulants were degraded from biopolymers (10-200 kDa) to low molecular weight substances (0.1-1 kDa),and the particle size of these residual foulants decreased significantly as a result.The strong oxidation power of hydrogen peroxide/hydroxy radicals towards organic foulants was enhanced by Fe2+.Fe2+ played a significant role in the removal of hydraulically reversible fouling and irreversible fouling from the ceramic membrane.However,Fe2+(≥124 mg/L) increased the likelihood of forming secondary iron-organics aggregates.展开更多
文摘Due to its extensive use in shale gas exploration and development,oil-based drilling fluids generate large amounts of oil-bearing drill cuttings during the drilling process.The large amount of oil-bearing drill cuttings generated during the drilling process can lead to serious secondary contamination.In this study,a wetting agent FSC-6 with good hydrophobic and oleophobic properties was synthesized to construct an efficient oil removal system.For the first time,the mechanism of this system was analyzed by using the theory of adhesion function,interfacial tension and wettability.At the same time,a combined acoustic-chemical treatment process was applied to the wastewater and slag generated after the cleaning of the oil-bearing drill cuttings.The experimental results show that the application of this pollution-free technology can effectively solve the environmental pollution and resource recovery problems of oil-bearing drill cuttings.It meets the standard of drilling chips with oil content less than 2%in SY/T7422-2018“Oil-based drilling fluid drilling chips treatment system for oil and gas drilling equipment”.
基金supported by the National Natural Science Foundation of China (No. 21676180 and No. 21076143)the Key Technologies R&D Program of Tianjin (No. 15ZCZDSF00160)Tianjin Municipal Science and Technology Xinghai Program (No. KJXH2014-05)
文摘To deeply clean oily wastewater,molecular sieve residues(MSRs)were sufficiently recycled and utilized due to their high specific surface area,porous structure,and outstanding adsorption property.Molding MSRs(MMSRs)were prepared by adding additives(starch,citric acid,and soluble glass)to MSRs and were then filled into a fixed bed for adsorbing and separating the oil in wastewater.Sodium dodecylbenzenesulfonate was used to modify the MMSRs,and their adsorption property was also investigated.In addition,the MSRs were characterized by scanning electron microscopy,energy-dispersive X-ray spectroscopy,Brunauer–Emmett–Teller analysis,and Fourier transform infrared spectroscopy.The results indicated that MMSRs satisfied the filling requirement of fixed bed,and their dynamic adsorption capacity could reach 0.1854 mg g^?1.Furthermore,the static adsorption capacity of MMSRs achieved 1.7346 mg g^?1 in the optimum conditions,and the oil adsorption performance of modified MMSRs was further enhanced.Therefore,this work suggests that MSRs are promising alternatives in cleaning oily wastewater.
基金Scientific Research Fund of Zhejiang Provincial Education Department(Y202250501)SRT Research Project of Jiaxing Nanhu University。
文摘The integration of the photocatalytic effect into solar steam is highly desirable for addressing freshwater shortages and water pollution.Here,a ternary film structure for the adsorption and photothermal and photocatalytic treatment of wastewater was designed by combining the technique of self-assembled carbon nano paper with a nitrogen composite titanium dioxide(N-TiO_(2))deposited on the surface of carbon nanotubes(CNT)using polyvinylidene fluoride(PVDF)as a substrate.The photogeneration of reactive oxygen species can be promoted by rapid oxygen diffusion at the three-phase interface,whereas the interfacial photothermal effect promotes subsequent free radical reactions for the degradation of rhodamine B(93%).The freshwater evaporation rate is 1.35 kg·m^(-2)·h^(-1)and the solar-to-water evaporation efficiency is 94%.Importantly,the N-TiO_(2)/CNT/PVDF(N-TCP)film not only effectively resists mechanical damage from the environment and maintains structural integrity,but can also be made into a large film for outdoor experiments in a large solar energy conversion device to collect fresh water from polluted water and degrade organic dyes in source water simultaneously,opening the way for applications in energy conversion and storage.
基金supported by the National Natural Science Foundation of China(No.51708325)the Committee of Science and Technology Innovation of Shenzhen(No.KQJSCX20180320171226768)the Development and Reform Commission of Shenzhen Municipality(urban water recycling and environment safety program)
文摘Membrane fouling is an obstacle impeding the wide applications of ceramic membranes and organics are responsible for most of the membrane fouling issues in wastewater treatment.In this study,Fenton cleaning strategy was firstly proposed to clean ceramic membrane fouling in wastewater treatment.Fe2+ efficiently catalyzed fouling cleaning with H2O2 (1.5%) to recover the filterability of ceramic membrane.The maximum ΔTMP recovery (over 99%) was achieved at an optimal Fe2+ dosage of 124 mg/L after 6 hr of immersion cleaning.The total residual membrane fouling resistance decreased gradually from this optimum value as the Fe2+ dosage increased above 124 mg/L.The residual hydraulically reversible fouling resistance accounted for most of the membrane fouling and was basically removed (≤3.0 × 109 m-1) when Fe2+ dosages higher than 124 mg/L were used.The foulants responsible for the formation of a residual hydraulically reversible fouling layer (DOC (dissolved organic carbon),proteins,polysaccharides,EEM (fluorescence excitationemission matrix spectra),SS (suspended solids),and VSS (volatile suspended solids)) were gradually removed as the Fe2+ dosage increased.These residual organic foulants were degraded from biopolymers (10-200 kDa) to low molecular weight substances (0.1-1 kDa),and the particle size of these residual foulants decreased significantly as a result.The strong oxidation power of hydrogen peroxide/hydroxy radicals towards organic foulants was enhanced by Fe2+.Fe2+ played a significant role in the removal of hydraulically reversible fouling and irreversible fouling from the ceramic membrane.However,Fe2+(≥124 mg/L) increased the likelihood of forming secondary iron-organics aggregates.
