Nanomembrane Canister Architectures for the Visualization and Filtration of Oxyanion Toxins with One-Step Processing

Inorganic-organic mesoporous hybrid segregators for selective and sensitive extraction of precious elements from urban mining

This study aimed to develop a highly selective extraction protocol for gold (Au^III) ions from electronic urban waste (EUW) using simple, low-cost Inorganic-organic mesoporous hybrid segregators. The unique features of mesoporous hybrid segregator architectures are of particular to ensure effective adsorption system in terms of selective and sensitive recovery of Au^III ions from EUW. The segregator platform featured 3D micrometric, mesocage double-serrated plant-leaf-like γ-Al₂O₃ sheets with hierarchy surfaces containing tri-modal mesopores interiorly and uniformly arranged toothed edges of ~20-40 and ~15 nm groove width and depth at the exterior surfaces, respectively. Rational incorporation of actively organic chelates into hierarchical γ-Al₂O₃ sheet platforms leads to the production of a couple of selective segregators 1 and 2 (namely, SC1 and SC2) for Au^III ions at specific conditions by applying batch and fixed-bed columnar techniques. The mesocage SC segregators offer a selective extraction approach of Au^III ions from mixed element contents released from a computer motherboard (CMB). Our finding indicated that the textural and hierarchal features of the mesocage SC segregators played key roles in the selective adsorption/recovery of Au^III ions at pH 2-2.5 with high capacity (136-141 mg/g range) and effective reusability ≫10 consecutive cycles. In general, the developed SCs could be utilized as a real extractor of Au^III recovery from spent CMBs.

Mesoscopic engineering materials for visual detection and selective removal of copper ions from drinking and waste water sources

The monitoring and removal of abundant heavy metals such as Cu ions are considerable global concerns because of their severe impact on the health of humans and other living organisms. To meet this global challenge, we engineered a novel mesoscopic capture protocol for the highly selective removal and visual monitoring of copper (Cu²⁺) ions from wide-ranging water sources. The capture hierarchy carriers featured three-dimensional, microsized MgO mesoarchitecture rectangular sheet-like mosaics that were randomly built in horizontal and vertical directions, uniformly arranged sheet faces, corners, and edges, smoothly quadrilateral surface coverage for strong Cu²⁺-to-ligand binding exposure, and multidiffusible pathways. The Cu²⁺ ion-selectively active captor surface design was engineered through the simple incorporation/encapsulation of a synthetic molecular chelation agent into hierarchical mesoporous MgO rectangular sheet platforms to produce a selective, visual mesoscopic captor (VMC). The nanoscale VMC dressing of MgO rectangular mosaic hierarchy by molecularly electron-enriched chelates with actively double core bindings of azo- and sulfonamide- groups and hydrophobic dodecyl tail showed potential to selectively trap and efficiently remove ultratrace Cu²⁺-ions with an extreme removal capability of ~233 mg/g from watery solutions, such as drinking water, hospital effluent, and food-processing wastewater at specific pH values. In addition to the Cu²⁺ ion-selective removal, the VMC design enabled the continuous visual monitoring of ultratrace Cu²⁺ ions (~3.35 × 10^-8 M) as a consequence of strong chelate-to-Cu²⁺ binding events among all accumulated matrices in water sources. Our experimental recycle protocol provided evidence of reusability and recyclability of VMC (≥10 cycles). With our mesoscopic capture protocol, the VMC can be a promising candidate for the selective decontamination/removal and sensitive detection of hazardous inorganic pollutants from different water sources with indoor or outdoor applications.

Recent advances in the synthesis and applications of mordenite zeolite - review

Among the many industrially important zeolites, mordenite is found to be interesting because of its unique and exceptional physical and chemical properties. Mordenite (high silica zeolite) is generally prepared by the hydrothermal method using TEA+ cations. TEA+ cations are the best templating agent, though they can create a number of issues, for instance, generating poison and high manufacturing cost, wastewater contamination, and environmental pollution. Hence, it is necessary to find a mordenite synthesis method without using an organic template or low-cost template. In this review, a number of unique sources were used in the preparation of mordenite zeolite, for instance, silica sources (rice husk ash, silica gel, silica fumes), alumina sources (metakaolin, faujasite zeolite) and sources containing both silica and alumina (waste coal fly ash). These synthesis approaches are also based on the absence of a template or low-cost mixed organic templates (for instance, glycerol (GL), ethylene glycol (EG), and polyethylene glycol 200 (PEG)) or pyrrolidine-based mesoporogen (N-cetyl-N-methylpyrrolidinium) modifying the mordenite framework which can create unique properties. The framework properties and optical properties (indium-exchanged mordenite zeolite) have been discussed. Mordenite is generally used in alkylation, dewaxing, reforming, hydrocracking, catalysis, separation, and purification reactions because of its large pore size, strong acidity, and high thermal and chemical stability, although the applications are not limited for mordenite zeolite. Recently, several applications such as electrochemical detection, isomerization, carbonylation, hydrodeoxygenation, adsorption, biomass conversion, biological applications (antibacterial activity), photocatalysis, fuel cells and polymerization reactions using mordenite zeolite were explored which have been described in detail in this review.

Compressive Alginate Sponge Derived from Seaweed Biomass Resources for Methylene Blue Removal from Wastewater

Low cost fabrication of water treatment polymer materials directly from biomass resources is urgently needed in recent days. Herein, a compressive alginate sponge (AS) is prepared from seaweed biomass resources through a green two-step lyophilization method. This material is much different from conventional oven-, air-, vacuum-dried alginate-based adsorbents, which show limitations of shrinkage, rigidness, tight nonporous structure and restricted ions diffusion, hindering its practical applications, and was used to efficiently remove methylene blue (MB), a main colorful contaminant in dye manufacturing, from wastewater. The batch adsorption studies are carried out to determine the impact of pH, contact time and concentration of dye on the adsorption process. The maximum adsorption capacity can be obtained at 1279 mg g-1, and the shape-moldable AS can be facilely utilized as a fixed-bed absorption column, providing an efficient approach for continuous removal of MB within a short time. It is also important that such a compressive AS can be regenerated by a simple squeezing method while retaining about 70% capacity for more than ten cycles, which is convenient to be reused in practical water treatment. Compressive AS demonstrates its merits of high capability, large efficiency and easy to recycle as well as low cost resources, indicating widespread potentials for application in dye contaminant control regarding environmental protection.