Support Platform of Functionalized Sustainable Cellulose Self-Entanglement Monolithic Adsorbents for Efficient Adsorption of Cadmium(II) Ions.

Serious water contamination induced by massive discharge of cadmium(II) ions is becoming an emergent environmental issue due to high toxicity and bioaccumulation; thus, it is extremely urgent to develop functional materials for effectively treating with Cd2+ from wastewater. Benefiting from abundant binding sites, simple preparation process, and adjustable structure, UiO-66-type metal-organic frameworks (MOFs) had emerged as promising candidates in heavy metal adsorption. Herein, monolithic UiO-66-(COOH)2-functionalized cellulose fiber (UCLF) adsorbents were simply fabricated by incorporating MOFs into cellulose membranes through physical blending and self-entanglement. A two-dimensional structure was facilely constructed by cellulose fibers from sustainable biomass agricultural waste, providing a support platform for the integration of eco-friendly UiO-66-(COOH)2 synthesized with lower temperature and toxicity solvent. Structure characterization and bath experiments were performed to determine operational conditions for the maximization of adsorption capacity, thereby bringing out an excellent adsorption capacity of 96.10 mg/g. UCLF adsorbent holding 10 wt % loadings of UiO-66-(COOH)2 (UCLF-2) exhibited higher adsorption capacity toward Cd2+ as compared to other related adsorbents. Based on kinetics, isotherms, and thermodynamics, the adsorption behavior was spontaneous, exothermic, as well as monolayer chemisorption. Coordination and electrostatic attraction were perhaps mechanisms involved in the adsorption process, deeply unveiled by the effects of adsorbate solution pH and X-ray photoelectron spectroscopy. Moreover, UCLF-2 adsorbent with good mechanical strength offered a structural guarantee for the successful implementation of practical applications. This study manifested the feasibility of UCLF adsorbents used for Cd2+ adsorption and unveiled a novel strategy to shape MOF materials for wastewater decontamination.

Structured electroplating sludge derived membrane for one-step removal of oil, metal ions, and anions from oil/water emulsions.

The effective simultaneous treatment of hazardous waste sludge and complex oil/water emulsions in one way is urgently desired but still a challenging issue. Herein, this work for the first time presents a green and efficient strategy to fabricate an electroplating sludge (ES) derived multifunctional self-supporting membrane for the one-step removal of emulsified oils, soluble metal ions, and anions in complex oily wastewater. Due to low cost of ES and sustainability of the solvent selected in fabrication process, the large-scale application of the membrane is easily to promote. The assembled hierarchical nanostructure endowed robust underwater superoleophobicity of the membrane even under various corrosive aqueous environments, as well as excellent ultra-low oil adhesion and anti-oil-fouling performance, without chemical modification. Significantly, the multifunctional membrane possessed desirable simultaneous separation efficiency for five typical oil-in-water emulsions (>99.4%, high oil/water selective wettability), including crude oil-in-water emulsion with high viscosity (>99.6%), Cu2+ (>96.1%, surface complexation and ionic exchange), and Cl- (>92.7%, electrostatic attraction). Therefore, this green, low-cost, and multifunctional membrane not only allows the large-scale resource utilization of hazardous waste sludge, but also effectively solves the problems of complex oily wastewater purification.

Facile fabrication of solar-heating and Joule-heating hyperelastic MXene-modified sponge for fast all-weather clean-up of viscous crude oil spill.

Developing rational sorbent for viscous crude oil clean-up is still a daunting challenge, which requires rapid oil-uptake capability and scalable fabrication process. Herein, a heatable hydrophobic sponge sorbent (H-MXene/PVA/MS) with excellent light/Joule-heating performances was fabricated by a simple and feasible top-down approach. MXene nanosheets firmly coated on the substrate skeleton gave the sorbent outstanding ability to convert solar/electricity into heat rapidly due to the localized surface plasmon resonance (LSPR) effect and ultrahigh metallic conductivity. The surface temperature of H-MXene/PVA/MS could reach about 80 â„ƒ under 1.0 sun irradiation within 30 s and 125 â„ƒ under a low applying voltage of 6 V within 25 s. The rapid and sufficient heat generation on the sorbent would effectively warm the surrounding oil and accelerate its absorption. The oil absorption rate under 1.0 sun irradiation (1 kW/m2) improved about 41.5 times compared to the unheated sorbent. Moreover, the sorbent showed practical application potential in harsh environments due to its high coating firmness, durability, elasticity, and suitability for large-scale production and operations. Thus, the easily-prepared H-MXene/PVA/MS sorbent, which mainly focuses on solar-heating, supplemented by Joule-heating, provides an efficient and energy-efficient strategy for addressing large-scale viscous oil spill clean-up.

Toxic waste sludge derived hierarchical porous adsorbent for efficient phosphate removal.

Global effective treatment of phosphorus crisis and toxic waste sludge in one way is urgently needed but still insufficient due to single function, environmental damage, and complicated fabrication process. Herein, we proposed a facile, low-cost, and sustainable strategy to fabricate NiAl layered double oxides/nickel-containing sludge (LDOs/NCS) adsorbent using toxic NCS as raw material via two-step method including hydrothermal process and calcination. The as-designed hierarchical porous adsorbent with large specific surface area and pore volume exhibited excellent adsorption properties towards phosphate. Langmuir adsorption model exhibited the best fit to the experimental data, which illustrated that the adsorption process was dominated by monolayer adsorption. Moreover, even in various double anions systems or in a wide pH range environment (2-12), the as-designed LDOs/NCS still maintained relatively stable adsorption capacity. A possible adsorption mechanism involving surface complexation and electrostatic interactions was investigated. Besides, the LDOs/NCS also displayed admirable durability and reusability. Therefore, this waste-control-waste strategy not only simultaneously addresses phosphorus crisis treatment and toxic NCS management, but also could be potentially extended towards rational design of other metals-containing sludge derived functional materials.

Structured sludge derived multifunctional layer for simultaneous separation of oil/water emulsions and anions contaminants.

The effective treatment of complex oily wastewater is of great significance but still a considerable challenge, since single-function, expensive reagents, and complicated process have emerged as shackles for practical applications. Herein, with the objective to waste-control-waste, we proposed a facile and sustainable strategy to fabricate a low-cost multifunctional layer from hazardous waste aluminum sludge (WAS) for complex oily wastewater management. The as-designed layered double oxides/WAS (LDOs/WAS) layer with three-dimensional (3D) hierarchical rough surface exhibited excellent underwater superoleophobicity even under corrosive conditions and low adhesion to oil without any chemical modification reagent treatment. Significantly, the layer can be applied to gravity-directed simultaneous efficient oil-in-water emulsions and anions (taking phosphate as an example) separation with a separation efficiency for emulsion and phosphate up to 99.4% and 99.1%, respectively, and a high separation flux of above 2585 L m-2 h-1. Notably, the flux can be controlled simply and flexibly by adjusting the thickness of the layer. Furthermore, the layer also displayed excellent thermal stability, chemical stability, durability and recyclability. Therefore, this work not only presents a promising approach to design sludge-based multifunctional materials for complex oily wastewater remediation, but also shows great potential and value in environmental pollutions reduction and industrial applications.

Construction of lignin-based nano-adsorbents for efficient and selective recovery of tellurium (IV) from wastewater.

Tellurium is massively used as the main light-absorbing layer component in the manufacturing of CdTe thin-film solar cells, a critical component in the photovoltaic industry. However, the process of manufacturing and renewing components has produced large amounts of tellurium-containing wastewater that is difficult to degrade and poses a serious threat to the aquatic ecosystem and human health. Hence, to achieve the recovery of tellurium resources for reducing their damages, a win-win approach was employed to utilize waste lignin to construct functional copper-doped activated lignin (CAL) adsorbents for selective separation and recovery of tellurium from wastewater. CAL exhibited superior adsorption properties towards tellurium (248.45 mg/g), mainly attributed to the adsorption mechanism of coordination interactions. Kinetic and isotherm results elucidated that monolayer chemisorption dominated CAL adsorption process. Besides, CAL had a satisfactory regeneration capability with minimal loss adsorption capacity after six consecutive cycles, which also exhibited high antifouling properties. Meanwhile, CAL achieved high selectivity for tellurium adsorption under the simulated wastewater, revealing the potential of CAL for practical application in wastewater. Therefore, this work provides a promising environmental strategy for exploring the application of lignin-based materials for tellurium recovery from wastewater.

Solar-heating superhydrophobic modified melamine sponge for efficient recovery of viscous crude oil.

Developing self-heating sorbents for rapid clean-up of viscous oil spills by using clean solar energy is attracting attention. Still, simple and scalable fabrication approaches of solar-heating sorbents remain challenging. Herein, a facile and practical modification strategy was presented to develop a solar-heating modified melamine sponge (rGO/CNT/MS) by dip-coating layer-by-layer (LBL) electrostatic assembly of GO and CNT with opposite charges onto MS skeleton followed by thermal reduction, without any complicated microfabrication and hydrophobic modification processes. Based on the intercalation of CNT into rGO layers and strong conjugation/hyperconjugation synergy of rGO and CNT, the light sorption ability, photothermal conversion, hydrophobicity and mechanical properties of the rGO/CNT/MS sorbent were further improved compared to rGO/MS and CNT/MS. The surface temperature could reach 75 â„ƒ in 100 s under 1 sun radiation (1 kW m-2), which would effectively absorb crude oil by in-situ sunlight-heating to reduce its viscosity. The sorption speed increased by about 30 times compared with no sunlight irradiation, and the continuous sorption capacity was up to 1.71 g/cm2 at 610 s driven by pump force. The easily-prepared solar-assisted rGO/CNT/MS with high photothermal performance, corrosion resistance, mechanical compressibility, coating firmness and oil sorption ability showed huge potential application in oil spill recovery.

Recyclable structured toxic industrial nickel-containing sludge for efficient anionic contaminant adsorption.

Safe, efficient, and simultaneous treatment of toxic industrial sludge and anionic contaminant crisis in one route still remains a persistent global challenge. Herein, we proposed a facile waste-control-waste conceptual design strategy to develop low-cost and high-performance sludge-based adsorbent for not only recycling of toxic waste nickel-containing sludge (NCS) but for the efficient removal of anionic contaminants in wastewater. The as-designed Ni-Al layered double oxides/calcined NCS (Ni-Al LDOs/CNCS) (216.96 m2/g, 0.44 cm3/g) with hierarchical porous structure possessed a larger specific surface area and well-developed porosity compared with raw NCS (60.52 m2/g, 0.26 cm3/g). It was proved that a higher hydrothermal temperature (180 °C) and a longer hydrothermal time (24 h) both promote the in situ assembly of LDHs nanosheets on CNCS surface. Significantly, the sludge-based adsorbent displayed high adsorption capacity towards five representative anions including F- (~ 31.1 mg/g), SO42- (~ 37.7 mg/g), NO3- (~ 21.8 mg/g), Cl- (~ 28.0 mg/g), and H2PO4- (~ 35.8 mg/g). Furthermore, the adsorbent maintained desirable adsorption capacity even after 6 adsorption/desorption cycles. Therefore, this study could be potentially extended toward design of other industrial waste sludge-derived high value-added advanced materials and for wastewater treatment applications.

Easily Fabricated Low-Energy Consumption Joule-Heated Superhydrophobic Foam for Fast Cleanup of Viscous Crude Oil Spills.

Effective cleanup of viscous crude oil spills remains a persistent and crippling challenge. Herein, this work presents a Joule-heated superhydrophobic flower-like Cu8(PO3OH)2(PO4)4·7H2O-coated copper foam (SHB-CF@CP) for rapid cleanup of viscous crude oil spills via a facile strategy. The SHB-CF@CP shows outstanding water repellency and excellent stability of hydrophobicity in harsh environments. Due to the high electrical conductivity and thermal conductivity, it requires lower power energy consumption (less than 1 V of voltage input) to raise the temperature significantly, which dramatically reduces the viscosity of crude oil (from ∼2 × 105 to ∼60 mPa s) and then increases the oil absorption rate, effectively avoiding the poor mobility and ineffective absorption of viscous crude oil. Notably, the SHB-CF@CP can achieve continuous and quick cleanup of crude oil under in situ pumping force. The high-performance Joule-heated SHB-CF@CP sorbent with a strong porous skeleton, corrosion resistance, and low predicted operational costs holds a promise of promoting its practical applications in the cleanup of intractable and large-area viscous oil spills.

Facile fabrication of bifunctional ZIF-L/cellulose composite membrane for efficient removal of tellurium and antibacterial effects.

Fabrication of simple and efficient adsorbents is greatly vital to satisfy the requirements of removal of tellurium in wastewater treatment, yet remains challenging. Here, a facile and cost-effective strategy to develop ZIF-L coated self-crosslinking cellulose membrane (ZIF-L/SC membrane) for tellurium adsorption was presented. In-situ vertical growth of ZIF-L nanoplates with functional properties on membrane substrate is an available strategy, effectively remedying deficiency of pure nanosized sorbent in agglomeration problem and unhandy recovery. The SC membrane formed by strong hydrogen bonding among cellulose fibers is an excellent substrate, due to the favorable mechanical strength and abundant hydroxyl groups. The as-prepared ZIF-L/SC membrane shows advantageous morphology of large contact surface, fine thermal stability and eligible mechanical strength. The adsorption performance and possible mechanism of ZIF-L/SC membrane for Te (IV) were investigated by diverse characterization methods, showing admirable adsorption effect. Furthermore, the ZIF-L/SC membrane has excellent antibacterial properties, thus it is expected to deal with membrane fouling caused by microorganism breeding. Therefore, the bifunctional ZIF-L/SC membrane with excellent antibacterial activity is anticipated to be a promising candidate for efficient tellurium adsorbents, and simultaneously have potential in various fields in the future.

Hierarchical structurized waste brick with opposite wettability for on-demand oil/water separation.

Due to the variety of oily wastewater and complexity of separation system, it has put forward new challenge and requirement to separation materials for on-demand separation of various oil/water mixtures. Here, we reported a facile waste-to-resource strategy to rationally fabricate hierarchical ZnO nanopillars coating onto the surface of waste brick grains (ZnO/WBG) via simple physical process and in-situ growth technique. Specifically, the directly as-prepared ZnO/WBG possess superhydrophilic/underwater superoleophobic (UWSOB) properties and modified ZnO/WBG by organosilicon reagent possess quasi superhydrophobic/superoleophilic (SHOBI) properties. It is also worth noting that this discrete ZnO/WBG with opposite wettability can be accumulated into ZnO/WBG layer with numerous tortuous channel structure, making it feasible for on-demand separating various oil/water mixtures whether immiscible light- and heavy-oil/water mixtures or oil-in-water and water-in-oil emulsions. It has been demonstrated that the filter layers with opposite wettability exhibit high separation efficiency and flux, excellent chemical stability and admirable recyclability. Thus, this novel and cost-effective ZnO/WBG layer holds great promise for large-scale and versatile oil/water separation. Additionally, this work presents a sustainable perspective of effectively utilizing waste brick to construct workable functionalized materials with tremendous application potential, showing far-reaching value and significance in fundamental research and environmental protection.

Waste-to-resource strategy to fabricate functionalized material from waste brick.

Waste brick (WB), as a major type of construction and demolition waste, has posed much potential disasters to the environment and society due to the main disposal method of direct landfill. In this work, we presented a sustainable and promising recycling approach to transform WB into TiO2 nanoneedles functionalized waste brick grain material (TiO2/WBG) via a simple physical treatment and in-situ growth technique. The raw WBG can be as promising substrate material due to excellent chemical stability. After surface functionalization of TiO2 nanoneedles, the obtained TiO2/WBG exhibits significantly enhanced hierarchical porous structure. Based on the inherent chemical properties and hierarchical structure of TiO2 nanoneedles coating, TiO2/WBG shows special wettability of excellent underwater oleophobicity and photodegradability of organic pollutants. Besides, the modified TiO2/WBG with low-surface-energy chemical obtains fine hydrophobicity. Therefore, the as-prepared TiO2/WBG is believed to hold potential applications in oil/water separation, pollutant degradation and water purification. This work opens new avenues for effectively utilizing waste brick as resource to fabricate functionalized material with potential application value, showing far-reaching value and significance in fundamental research and environmental protection.

Ag nanoparticles coated cellulose membrane with high infrared reflection, breathability and antibacterial property for human thermal insulation.

To maintain personal thermal comfort in cold weather, indoor heating consumes large amount of energy and is a primary source of greenhouse gas emission. Traditional clothes are too thick for thermal comfort in cold outdoor environment, resulting the lower wearing comfort. In this work, a multifunctional Ag nanoparticles/cellulose fibers thermal insulation membrane starting from waste paper cellulose fibers was prepared via simple silver mirror reaction and subsequent vacuum filtration process to improve the infrared reflection properties of membranes for human thermal insulation. The sphere-like Ag nanoparticles were tightly anchored on surface of waste paper cellulose fibers, forming an Ag nanoparticles infrared radiation reflection coating with high infrared reflectance, resulting in high thermal insulation capacity of the thermal insulation membrane. In addition, Ag nanoparticles endow the thermo insulation membrane with excellent antibacterial activity, and the thermo insulation membranes can effectively inhibit the growth of both Staphylococcus aureus and Escherichia coli. In this thermal insulation system, the thermo insulation membranes show superhydrophilicity and porosity, which allow the membranes to be breathable for comfortable wearing feeling. These promising results including high infrared reflection for high thermal insolating, high breathability for wearing comfort, and excellent antibacterial activity make the Ag/cellulose thermo insulation membranes promising candidates for applications in human thermal management, energy regulation and other facilities.