ソクドロンテキ トクセイ ノ スグレタ ヒサン ナラビニ リンサン イオン ニ センタクテキ ナ キュウチャクザイ ノ カイハツ

This study has shown that FVA, Zr(IV) loaded phosphonate/sulfonate binfunctional fiber and PAA are highly effective new adsorbents for arsenate and phosphate removal with high kinetic performances

ソクドロンテキ トクセイ ノ スグレタ ヒサン ナラビニ リンサン イオン ニ センタクテキ ナ キュウチャクザイ ノ カイハツ

This study has shown that FVA, Zr(IV) loaded phosphonate/sulfonate binfunctional fiber and PAA are highly effective new adsorbents for arsenate andphosphate removal with high kinetic performances

The Utilization of Algae and Seaweed Biomass for Bioremediation of Heavy Metal-Contaminated Wastewater

The presence of heavy metals in water bodies is linked to the increasing number of industries and populations. This has serious consequences for the quality of human health and the environment. In accordance with this issue, water and wastewater treatment technologies including ion exchange, chemical extraction, and hydrolysis should be conducted as a first water purification stage. However, the sequestration of these toxic substances tends to be expensive, especially for large scale treatment methods that require tedious control and have limited efficiency. Therefore, adsorption methods using adsorbents derived from biomass represent a promising alternative due to their great efficiency and abundance. Algal and seaweed biomass has appeared as a sustainable solution for environmentally friendly adsorbent production. This review further discusses recent developments in the use of algal and seaweed biomass as potential sorbent for heavy metal bioremediation. In addition, relevant aspects like metal toxicity, adsorption mechanism, and parameters affecting the completion of adsorption process are also highlighted. Overall, the critical conclusion drawn is that algae and seaweed biomass can be used to sustainably eliminate heavy metals from wastewater

Assessment of clean H2 energy production from water using novel silicon photocatalyst

Nanosheets of silicon have attracted a great deal of attention due to its tunable optical and electronic properties. However, the development of facile and easily scalable synthesis process has remained a great contest. Endeavor has been made in this research to find a waste inferred effective photocatalyst to deliver hydrogen (H2) through visible light responsive water splitting. One-pot solid phase reaction was applied to synthesis catalyst and adopted ultrathin structure. The photocatalytic efficiency of catalyst was examined by XRD, XPS, and UV–VIS absorption spectra, PL, FESEM, HRTEM and EDX. The HRTEM and FESEM images revealed the interconnected nanosheets with Si having the average thickness of 5 nm and their band gaps were 2.3–2.5 eV corresponding to the absorption of visible light range. The H2 production rate on photocatalyst was originated to 3200 μmol h−1 without utilizing any conciliatory electron givers, voltage or pH alteration, which beats the Pt, Ru, Rh, Pd and Au stacked photocatalyst ever detailed up until this point. The significant increase in photocatalytic activity could be the fast charge migration and separation from the silicon-hydrogen and silicon-hydroxyl bonds on Si surface and facilitation of charge separation could results from the multiple reflections of visible light on ultrathin nanosheets. It has been confirmed that the electron/hole recombination rate in ultrathin nanosheets of Si declined due to the oxidation of Si surface. It would be presumed that the approach of surface chemistry of silicon could not be limited towards the photocatalytic water splitting and could be applicable to remedy water pollution

Ultrathin assembles of Porous Array for enhanced H2 evolution

Since the complexity of photocatalyst synthesis process and high cost of noble cocatalyst leftovers a major hurdle to producing hydrogen (H2) from water, a noble metal-free Ni-Si/MgO photocatalyst was realized for the first time to generate H2 effectively under illumination with visible light. The catalyst was produced by means of simple one-pot solid reaction using self-designed metal reactor. The physiochemical properties of photocatalyst were identified by XRD, FESEM, HRTEM, EDX, UV-visible, XPS, GC and PL. The photocatalytic activities of Ni-Si/MgO photocatalyst at different nickel concentrations were evaluated without adjusting pH, applied voltage, sacrificial agent or electron donor. The ultrathin-nanosheet with hierarchically porous structure of catalyst was found to exhibit higher photocatalytic H2 production than hexagonal nanorods structured catalyst, which suggests that the randomly branched nanosheets are more active surface to increase the light-harvesting efficiency due to its short electron diffusion path. The catalyst exhibited remarkable performance reaching up to 714 µmolh⁻¹ which is higher among the predominant semiconductor catalyst. The results demonstrated that the photocatalytic reaction irradiated under visible light illumination through the production of hydrogen and hydroxyl radicals on metals. The outcome indicates an important step forward one-pot facile approach to prepare noble ultrathin photocatalyst for hydrogen production from water

Ligand based sustainable composite material for sensitive nickel(II) capturing in aqueous media

© 2019 Elsevier Ltd. Organic ligand based sustainable composite material was prepared for the detection and removal of nickel (Ni(II)) ion from contaminated water. The ligand was anchored based on the building-block approach. The carrier silica and ligand embedded composite material were characterized systematically. The detection and removal of Ni(II) ion operation was evaluated according to the solution pH, reaction time, detection limit, initial Ni(II) concentration and diverse co-existing metal ions. The detection limit of Ni(II) ion by the proposed composite material was 0.41 μg L-1. The detection and removal of Ni(II) ion was significantly influenced by the solution pH. However, the neutral pH 7.0 was chosen for sensitive and selective detection and removal of Ni(II) ion. The co-existing diverse metal ions were not interfered during the detection and removal of Ni(II) ion because of the high affinity of Ni(II) ion to composite material at the optimum experimental conditions. The Langmuir adsorption isotherm model was selected based on the materials morphology and applied to validate the adsorption isotherms according to the homogeneous ordered frameworks. The adsorption capacity was 199.19 mg g-1 as expected due to the high surface area of material. The adsorbed Ni(II) ion was completely eluted from the composite material with the eluent of 0.50 M HCl and the regenerated material was used in several cycles without deterioration in its initial performances. Therefore, it is expected to that the Facile composite material may hold huge potentials in applications and may be scaled up for commercial applications, including environmental detection and removal of Ni(II) ion

HOGLA LEAF AS A POTENTIAL BIO-ADSORBENT FOR THE TREATMENT OF REACTIVE DYES IN TEXTILE EFFLUENTS

A new bio-adsorbent to remove reactive dyes from textile effluent was investigated in the present study. The adsorbent was the leaves of locally available hogla plant (Typha angustata). Initially, sunfix yellow, a reactive dye widely used in textile effluents, was used to check the removal efficiency in terms of contact time, pH of dye solution and adsorbent dosage. Complete removal (100%) of dye was achieved at adsorbent/dye ratio of 2300:1 at pH 10 with 180 minutes contact time. The adsorbent was then applied to deep colored, raw textile wastewater samples and it was found that 2.3 g of adsorbent was able to convert 100 mL of deep colored wastewater to transparent water at pH 10. Additionally, treatment by the adsorbent resulted in significant decreases in pH, BOD, COD, TS, TDS and TSS of wastewater, while improving the DO level

Advances in physiochemical and biotechnological approaches for sustainable metal recovery from e-waste: A critical review

A large amount of waste printed circuit boards (WPCBs) has been generated due to the tenacious scientific development and therefore, the improvement of expectations for everyday comforts. The unprecedented acceleration of electronic waste (e-waste) and informal disposal at end-of-life display the adverse impact of digitalization. Recently, home teleworking has increased a wide range of sectors and occupations which may eventually lead to increase the generation of e-waste. Effective management of e-waste is urgently required for protecting environment as well as human well-being’s. In view of the precious metal content and rare earth elements, WPCBs could become a sustainable source of precious metals. Appropriate eco-friendly strategies to recover metals from WPCBs are therefore imperative and crucial for e-waste management. Recent progress in metal recovery through gravity, density, electrostatic and integrated approaches were investigated dependent on previous contribution to provide an overview of present recycling status. The mechanism and factors influencing the metal recovery efficiency in a countercurrent operation were critically reviewed. The application of biotechnological approach for metal recovery was discussed from the theoretical and experimental views. The hazardous impact on human health and environment due to the toxic substances released from e-waste were highlighted. Finally, the limitations and perspectives towards the sustainable process for recovery of metals from e-waste were discussed

Step towards the sustainable toxic dyes removal and recycling from aqueous solution- A comprehensive review

The synthetic dyes and chemicals used in industries produce a tremendous amount of contaminated water. Most of the poisonous dyes generated from different textile industries are released directly to the environment. As a consequence, the discharge of wastewater from a large number of textile industries without prior treatment leads to significant negative impacts on human health. The utilization of efficient and inexpensive nano-adsorbent may reduce the adverse impacts of dyes in the environment due to their unique properties. To alleviate these issues, attention has been paid to develop efficient adsorbents for the removal of undesirable species from wastewater. Efficient and selective removal of dyes is gaining importance to reduce the environmental problems. Comparison of degradation efficiency for different catalysts could be a holistic approach that should be taken under consideration owing to search a suitable adsorbent. An in-depth evaluation of extensive variety of advanced adsorbents reported in literature for dye degradation has been furnished. In addition to underscoring the physico-chemical properties of different adsorbents, this review also endorses the mechanisms and efficiencies within the adsorption process. The challenges of dye degradation process are focused to reduce the adverse impacts of dyes in the environment. The critical assessment of next generation adsorbents would presumably be promoted the clean and affordable water purification process in practice

Preparation and evaluation of composite hybrid nanomaterials for rare-earth elements separation and recovery

A new technology is necessary to representing an entire process of separation and recovery of rare-earth lanthanides (Ln(III)) elements to keep the eco-system for stable industrial growth. In this study, novel hard and soft donor organic ligand containing mesoporous composite hybrid nanomaterial (CHM) was fabricated for specific ytterbium (Yb(III)) ion separation and recovery in sustainable method. The Yb(III) ion was selected based on the Ln(III) intra-series separation behavior in the solid-liquid separation approach. The present approach was based on basic research of individual process steps with the stable complexation mechanism according to the O- and N-donor coordination. The usual bond distance between Yb-O and Yb-N was 2.206 and 2.847 Å, which was clarified that the O-atom was hardly donating than the N-atom of the synthesized organic ligand. However, both atoms were coordinating with Yb(III) ions to clarifying the stable complexation and coordination mechanism. The optimum pH solution was evaluated before selecting the separation and uptake operations and the pH was 5.0 to avoid the hydroxyl precipitation rather than adsorption based on the Ln(III) chemistry. The fabricated CHM was exhibited the high kinetic performances. The adsorption data were highly fitted with the Langmuir isotherms model and the maximum Yb(III) adsorption amount was found 139. 19 mg/g. The results were also affirmed that the effect of competing ions were not affected seriously in the Yb(III) adsorption. After successful adsorption, the Yb(III) ion was recovered with elution operation using 0.40 M HNO3 and the CHM was also regenerated at the same time for next adsorption process after washing with water. Moreover, the reuses of the CHM were possible in several cycles complying the cost-effective potential material in real waste sample treatment