Preparation of Newly Polymer-Coated Microbial Pellets and Their Adsorption and Degradation Properties for Oil-Containing Wastewater.

Water is the lifeblood of everything on earth, nourishing and nurturing all forms of life, while also contributing to the development of civilization. However, with the rapid development of economic construction, especially the accelerated process of modern industrialization, the pollution of oily sewage is becoming increasingly serious, affecting the ecological balance and human health. The efficient elimination of pollutants in sewage is, therefore, particularly urgent. In this paper, a core-shell microbial reactor (MPFA@CNF-SA-AM) was fabricated by using nanocellulose and sodium alginate (SA) particles embedded with microorganisms as the core and lipophilic and hydrophobic fly ash as the outer shell layer. Compared with that of free microorganisms and cellulose and SA aerogel pellets loading with microorganisms (CNF-SA-AM), which has a degradation efficiency of 60.69 and 82.89%, respectively, the MPFA@CNF-SA-AM possesses a highest degradation efficiency of 90.60% within 240 h. So that this self-floating microbial reactor has selective adsorption properties to achieve oil-water separation in oily wastewater and high effective degradation of organic pollutants with low cost. The adsorption curves of MPFA@CNF-SA-AM for diesel and n-hexadecane were studied. The results showed that the adsorption follows the Freundlich model and is a multimolecular layer of physical adsorption. In addition, the degradation mechanism of diesel oil was studied by gas chromatography-mass spectrometry. The results showed that diesel oil was selectively adsorbed to the interior of MPFA@CNF-SA-AM, and it was degraded by enzymes in microorganisms into n-hexadecanol, n-hexadecaldehyde, and n-hexadecanoic acid in turn, and finally converted to water and carbon dioxide. Compared with existing oily wastewater treatment methods, this green and pollution-free dual-functional core-shell microbial reactor has the characteristics of easy preparation, high efficiency, flexibility, and large-scale degradation. It provides a new, effective green choice for oily wastewater purification and on-site oil spill accidents.

Porphyrin-Based Conjugated Microporous Polymer Loaded with Nanoscale Zerovalent Iron for the Degradation of Organic Pollutants under Visible Light.

The degradation of organic dye from waterbodies is of great significance for clean production and environmental remediation. Herein, two porphyrin-based conjugated microporous polymers (CMPs) loaded with nanoscale zerovalent iron (named as Por-CMPs-1-2@nZVI) were successfully fabricated by Sonogashira-Hagihara coupling reactions and the liquid-phase method. The as-synthesized Por-CMPs-1-2@nZVI composites were characterized by various means of analysis, and it was confirmed that Por-CMPs-1-2 loaded with nZVI had good photocatalytic performance. Calculated by ultraviolet-visible spectrum, the band-gap energies of Por-CMPs-1@nZVI and Por-CMPs-2@nZVI were 1.45 and 1.32 eV, respectively, indicating that both can be activated by visible light. The photodegradation of organic dye experiments demonstrated that Por-CMPs-2@nZVI degraded 98.0% of 10 ppm Methylene Blue (MB) within 150 min, which is higher than that of Por-CMPs-1-2 and Por-CMPs-1@nZVI. The experiment of active substance capture and mechanism of ESR confirmed that superoxide anion and hydroxyl radical were the primary valid substances in the photodegradation process of MB. In addition, the preparation of membrane materials was shown to be a successful strategy to realize engineered scale-up production.

Coffee Grounds-Doped Alginate Porous Materials for Efficient Solar Steam Generation.

Solar steam generation (SSG) devices have emerged as one of the promising technologies for seawater desalination to meet the worldwide demand for clean water. Herein, we fabricated a new monolithic SSG system derived from waste coffee grounds (CG) through a simple carbonization followed by a freeze-drying process (named as CCGA). The as-prepared CCGA possesses a porous structure with superhydrophilic, abundant porosity (81.7%); low thermal conductivity (0.129 W m-1 K-1) in a wet state; low apparent density (25 mg cm-3); and broad sunlight absorption in a wet state (ca. 93%). The combination of its carbon nature and abundant porous structure endowed barrier-free water transmission channels, a self-floating property, and a superb photothermal conversion performance to the SSG. The temperature of the CCGA's upper surface can reach up to 42.6 °C under 1 sun irradiation, and for pure water, the evaporation rate of CCGA can be up to 1.486 kg m-2 h-1, corresponding to a good photothermal conversion efficiency of 86.96%. It also exhibits an excellent desalination capability; e.g., the photothermal conversion efficiency of CCGA in NaCl (20 wt %) brine is measured to be 75.77% under 1 sun irradiation, and the fresh water obtained from artificial seawater can achieve the WHO's standard for domestic water. With the advantages of low cost and a simple preparation process, such biomass-based CCGA materials may have great potential as an efficient SSG device for seawater desalination.

Porphyrin-Based Conjugated Microporous Polymers for Highly Efficient Adsorption of Metal Ions.

The capture and elimination of anions and cations from water have attracted a great deal of attention and are quite vital for clean production and environmental remediation. In this work, we present the synthesis of four porphyrin (Por)-based conjugated microporous polymers (CMPs, namely, Por-CMP-1-4), which were produced through a Sonogashira-Hagihara linked response using porphyrin and acetylene aromatic compounds as building blocks and used as absorbents to eliminate metal ions from water. The as-synthesized Por-CMP-1-4 exhibit an amorphous porous structure and outstanding caloric and physicochemical properties. Taking advantage of their larger specific surface areas, i.e., 541.47, 614.58, 382.38, and 677.90 m2 g-1 for Por-CMP-1-4, respectively, and their chelating active site that originated from the porphyrin ring, Por-CMP-1-4 show better Zn2+, Cu2+, and Pb2+ adsorption ability. Among them, Por-CMP-3 has the greatest adsorbability of 640 mg g-1 for Zn2+, with an adsorption efficiency of 80%, whereas its adsorption capacities for Cu2+ and Pb2+ ions were both 334 mg g-1, with an adsorption efficiency of 42% for Cu2+ and Pb2+. Employing Por-CMP-3 as a representative example, its adsorption kinetics has been systematically investigated. The adsorption behavior of Por-CMP-3 with respect to the Zn2+ ion is shown to exhibit pseudo-first-order kinetics and Langmuir isotherm modes. Meanwhile, the adsorption mechanism is discussed in detail, and it was thought it might be chelation, in which the nitrogen atoms with a single pair of electrons on the porphyrin ring interacted with metal ions to form stable chelation coordination bonds, thus removing metal ions selectively and effectively. Furthermore, Por-CMP-3 exhibited good reusability, retaining 60% of its Zn2+ removal rate after four continuous adsorptions.

Fe3O4/PPy-Coated Superhydrophilic Polymer Porous Foam: A Double Layered Photothermal Material with a Synergistic Light-to-Thermal Conversion Effect toward Desalination.

Solar steam generation has been considered as one of the most promising strategies for production of fresh water using renewable solar energy. Herein, we prepared a polymer porous foam (HPSS) by a facile hydrothermal method. The HPSS presents a superhydrophilic wettability, an interpenetrating macroporous structure, and low thermal conductivity, which can well satisfy the criteria as an ideal candidate for photothermal materials. The HPSS/Fe3O4/PPy (polypyrrole) evaporator, of which a Fe3O4/PPy binary optical system served as a light absorption layer and HPSS was used as a porous substrate, was constructed through in situ growth of Fe3O4 particles followed by interfacial polymerization of PPy on the surface of HPSS. HPSS/Fe3O4/PPy shows an excellent light absorption capacity (92%) and photothermal conversion performance, with the solar energy conversion efficiency reaching up to 94.7% under 1 sun irradiation, which is much higher than that of HPSS/PPy (84.8%) composed of a unitary PPy light absorption layer. Interestingly, the presence of Fe3O4 particles could make directional migration in a magnetic field possible, thus facilitating its recovery as a self-floating solar generator in an open water area. Moreover, the HPSS/Fe3O4/PPy evaporator displays outstanding salt resistance properties and stability in various saline solutions, thus having great potential in practical desalination.

Starch hydrogel with Poly(ionic liquid)s grafted SiO2 for efficient desalination and wastewater purification.

Solar-driven interface evaporation is promising to alleviate the fresh water scarcity in an economical and sustainable way. However, most of currently reported photothermal conversion materials (PMs) are time-consuming costly, inefficient, or complex preparation process, which causes low utilization efficiency, and difficult to be practical for large-scale application. To solve this problem, a facile and green strategy for preparing hydrogel evaporator (SiO2-PILs/starch) by grafting poly(ionic liquid)s onto silica and doping it with starch is proposed. Benefiting from the broad solar absorption (ca.91 %), strong hydrophilic, and superb salt tolerance and stain resistance of SiO2-PILs/starch. Under 1 sun irradiation, the SiO2-PILs/starch achieves a remarkable solar evaporation efficiency of 91.72 % in pure water and 81.45 % in 20 wt% NaCl solution, respectively. In particular, SiO2-PILs/starch exhibited outstanding long-term salt stability (8 h) and crystalline salt can be self-cleaned in the dark environment. It is worth noting that the prepared hydrogel also possesses a satisfied evaporation efficiency of 75.84 % in oily wastewater (3 wt% n-hexadecane solution) due to its excellent water retention. These properties of SiO2-PILs/starch may provide desperately needed solution for efficient desalination and guaranteed high applicability and durability in practice.

A one-dimensional silver(I) coordination polymer based on the 2-[2-(pyridin-4-yl)-1H-benzimidazol-1-ylmethyl]phenol ligand exhibiting photoluminescence.

A one-dimensional Ag(I) coordination complex, catena-poly[[silver(I)-µ-{2-[2-(pyridin-4-yl)-1H-benzimidazol-1-ylmethyl]phenol-κ(2)N(2):N(3)}] perchlorate monohydrate], {[Ag(C19H15N3O)]ClO4·H2O}n, was synthesized by the reaction of 2-[2-(pyridin-4-yl)-1H-benzimidazol-1-ylmethyl]phenol (L) with silver perchlorate. In the complex, the L ligands are arranged alternately and link Ag(I) cations through one benzimidazole N atom and the N atom of the pyridine ring, leading to an extended zigzag chain structure. In addition, the one-dimensional chains are extended into a three-dimensional supramolecular architecture via O-H···O hydrogen-bond interactions and π-π stacking interactions. The complex exhibits photoluminescence in acetonitrile solution, with an emission maximum at 390 nm, and investigation of the thermal stability reveals that the network structure is stable up to 650 K.

2-{[2-(Pyridin-4-yl)-1H-benzimidazol-1-yl]meth-yl}phenol.

In the title compound, C19H15N3O, the benzimidazole ring system makes dihedral angles of 44.36 (7) and 75.67 (7)° with the pyridine and benzene rings, respectively. In the crystal, phenolic O-H⋯N hydrogen bonds to benzimidazole N-atom acceptors give rise to a chain extending along [011].

MXene/polypyrrole coated melamine-foam for efficient interfacial evaporation and photodegradation.

The application of photothermal materials in seawater desalination, wastewater treatment have been widely studied, however, there are relatively few studies that combine photothermal effects and solar-driven photocatalysis and exhibit efficient solar-driven water evaporation performance and excellent photocatalytic ability. Form the perspective of practical application, it is of great significance to combine photothermal effect with solar-driven photocatalysis to develop environment-friendly evaporator with low cost, simple preparation process and ability of seawater desalination, wastewater treatment and photodegradation of organic dyes. In this paper, a novel multifunctional MXene/polypyrrole (PPy) coated melamine foam (MF) named as MF-MXene/PPy was successfully prepared by simple impregnation and in-situ polymerization. The MF-MXene/PPy has rich porosity (89.13 %), abundant water molecule transport channels, excellent light absorption capacity (about 94 %), low thermal conductivity (0.1047 W m-1 K-1), and exhibits excellent performance in solar desalination, wastewater purification and photodegradation of organic dyes. Under 1 kW m-2 illuminate, the solar energy conversion rate and efficiency of MF-MXene/PPy reaches up to 1.5174 kg m-2h-1 and 91.24 %. Moreover, due to the regular pore size of MF-MXene/PPy, good salinity tolerance was shown even after continuous evaporation in 20 wt% NaCl for 8 h. After continuous evaporation in 70 mL of 20 wt% NaCl for 8 h, the amount of salt collected could reach 0.2 g. In addition, MF-MXene/PPy also possessed excellent visible light degradation ability for organic dyes, and the degradation rate of methylene blue (MB), rhodamine B (RHB) and methyl orange (MO) were 92.38 %, 88.92 % and 91.75 %, respectively. As a fundamental research, this research will open a novel way to the development of new evaporator.

Aqua-[1-(pyrazin-2-yl)ethanone oximato-κ²N,N'][1-(pyrazin-2-yl)ethanone oxime-κ²N,N'](thio-cyanato-κN)nickel(II).

In the title complex, [Ni(C6H6N3O)(NCS)(C6H7N3O)(H2O)] or [Ni(mpko)(SCN)(mpkoH)(H2O)] [where mpkoH = 1-(pyrazin-2-yl)ethanone oxime], the Ni(II) cation is in a slightly distorted octa-hedral geometry, being coordinated in the equatorial plane by four N atoms from two different mpkoH ligands, one of which is deprotonated, and by one N atom from a thio-cyanate anion and one O atom from a water mol-ecule in the axial positions. There is an intra-molecular O-H⋯O hydrogen bond involving the oxime units of the two ligands. In the crystal, a three-dimensional supra-molecular architecture is formed by O-H⋯O and O-H⋯N hydrogen bonds.

Dimethyl 2,2'-[2,2'-bi(1H-1,3-benzimidazole)-1,1'-di-yl]diacetate.

The whole mol-ecule of the title compound, C(20)H(18)N(4)O(4), is generated by an inversion center. The benzimidazole ring mean plane make a dihedral angle of 89.4 (8)° with the plane passing through the acetate group (COO). In the crystal, mol-ecules are linked via weak C-H⋯O hydrogen bonds and π-π inter-actions [centroid-centroid distance = 3.743 (3) Å] involving inversion-related benzimidazole groups.

Bis{2-[bis-(3,5-dimethyl-1H-pyrazol-1-yl-κN(2))meth-yl]pyridine-κN}cobalt(II) dinitrate.

The central Co(II) ion in the title complex, [Co(C(16)H(19)N(5))(2)](NO(3))(2), is located on a twofold rotation axis and has a slightly distorted octa-hedral coordination sphere. It is bonded to six N atoms from two 2-[bis-(3,5-dimethyl-1H-pyrazol-1-yl)meth-yl]pyridine ligands. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions.

MXene-doped kapok fiber aerogels with oleophobicity for efficient interfacial solar steam generation.

Although the evaporation efficiency of photothermal materials (PMs) in pure water and brine solutions has been extensively studied, there few research on the performance in complex oily wastewater. Herein, a new monolithic solar steam generator derived from kapok fiber-based MXene composite aerogel (named as KFs-MXene) was fabricated by dipping the aerogels (KFs) which composed of kapok fiber and sodium alginate (SA) as substrates in the suspension of MXene. Benefitting from the outstanding light absorption (about 97%), better thermal insulation (thermal conductivity, 0.05039 W m-1 K-1), abundant porosity (95.60%) and rapid water transportation. KFs-MXene show good interfacial solar steam generation (ISSG) performance, resulting in a high water evaporation rate of 1.47 kg m-2h-1 with an outstanding evaporation efficiency of 90.4% under 1 kW m-2 irradiation. To improve the antifouling performance of KFs-MXene, chemically hydrophilic and oleophobic modification was applied, making the KFs-MXene can also be widely used in oily wastewater. Under 1 kW m-2 illumination, the evaporation rate and energy conversion efficiency of KFs-MXene with hydrophilic and oleophobic modification (O-KFs-MXene) in 1 wt% oily water can reach to 1.40 kg m-2h-1 and 82.87%, and the evaporation efficiency and rate of O-KFs-MXene remain stable in the continuous 6 h solar driven interface evaporation process.

Hollow SiO2 microspheres in-situ doped poly(ionicliquid)s gels as efficient solar steam generators for desalination.

Solar steam generation (SSG) is one of the promising technologies for seawater desalination and contaminated water purification. However, SSG devices are always restricted by poor insulation performance, insufficient solar spectrum absorption and serious salt-fouling. Here, a double-layered novel SSG system was fabricated by using poly(ionicliquid)s gels with hollow SiO2 microspheres in-situ doping to enhance the thermal insulation of lower layer, and co-modified the top surface by polypyrrole (PPy) and silver particles to strengthen the solar absorption capability. Benefiting from the low thermal conductivity (0.082 W m-1 k-1), strong light absorption (ca. 96%) and adequate water transport capability of poly(ionic liquid)s gels. As SSG device, a superb photothermal conversion efficiency of 90.5% is achieved under 1 sun illumination. Moreover, the poly(ionic liquid)s gels based SSG system also shows good desalination performance in artificial sea water and high concentration brine, and the purified water from artificial seawater can achieve the WHO's standard for drinking water. Therefore, this work combined attractive in-situ doping and co-modified strategies for fabricating high performance and thus shows significant potential for real applications.

Bis{2-[bis-(3,5-dimethyl-1H-pyrazol-1-yl-κN)meth-yl]pyridine-κN}copper(II) dinitrate.

In the mononuclear title complex, [Cu(C(16)H(19)N(5))(2)](NO(3))(2), the Cu(II) ion is located on a twofold rotation axis and is six-coordinated by six N atoms from two 2-[bis-(3,5-dimethyl-1H-pyrazol-1-yl)meth-yl]pyridine ligands, forming a distorted octa-hedral geometry. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions.

High-Performance Salt-Rejecting and Cost-Effective Superhydrophilic Porous Monolithic Polymer Foam for Solar Steam Generation.

Direct solar desalination with excellent solar photothermal efficiency, lower cost, and extended generator device lifetime is beneficial to increase potable water supplies. To address fundamental challenges in direct solar desalination, herein, we present a new and facile method for the scalable fabrication of the polymer porous foam (VMP) as salt-resistant photothermal materials, which was synthesized through a one-step hydrothermal method using styrene and 1-vinyl-3-ethylimidazolium tetrafluoroborate as monomers and N,N'-methylenebisacrylamide as the cross-linking agent. The as-resulted VMP shows excellent mechanical properties which could have a compression strain of 30%, resulting in its superior processability for practical operation. In addition, by taking advantage of its inherent low density, well-controlled porous structure (porosity is 73.81%), and extremely low thermal conductivity (0.03204 W m-1 K-1), the VMP exhibits an excellent solar evaporation property, and the solar photothermal efficiency can reach more than 88% under 1 kW m-2 irradiation. Moreover, the introduction of ionic liquid moiety (imidazolium tetrafluoroborate) into VMP results in its interesting superhydrophilic wettability, which can accelerate water transportation (wetting in 5s) and resolve the crystalline salt within 1.13 h. In addition, the interconnected macropores of the VMP, as water channels, can replenish the vaporized brine on the surface to prevent salt from adhering. The VMP shows a salt-resistant performance, for example, its solar evaporation efficiency remains nearly unchanged after 6 h duration under 1 sun irradiation. Based on its simple and cost-effective manufacturing process, excellent solar photothermal efficiency, and salt resistance, our VMP may be a promising candidate as photothermal materials for practical desalination from seawater and other wastewater.