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41.
The aim of this study is to reduce the phosphate concentration in treated wastewater using a small amount of the reactive filter media, Filtralite P. Biologically treated wastewater was passed through a filter with 215 g of Filtralite P. In the laboratory, the phosphate removal efficiency was 51% at a flow speed of 0.87 m/h. Under real conditions, in an experimental stand filled with 0.5 m3 of Filtralite P, the phosphate removal efficiency was 85% and the removal efficiency of total suspended solids was 57% after a 5‐month period. The residual phosphate concentration in the filtrate from the experimental stand was 1 mg/L of PO4‐P after the 5‐month period. The experimental filtration plant was buried in the ground, and it did not freeze and worked well under winter conditions. The results of this study can be useful in the design and development of tertiary wastewater treatment plants in view of their sustainability potential. 相似文献
42.
《Advanced Powder Technology》2021,32(9):3174-3188
Granular activated carbon (GAC) filtration is an important unit operation in drinking water treatment. GAC filtration is widely used for its filtration and adsorption capabilities as a barrier for undesired organic macro- and micro-pollutants. GAC filtration consists of two successive phases: adsorption and filtration, capturing the impurities from the water in conjunction with a backwash procedure in which the suspended particles are flushed out of the system. Available literature predominantly focusses on adsorption. A less frequently discussed but nevertheless equally crucial aspect of this operation is the backwash procedure of GAC beds. To prevent accumulation of suspended particles and to avoid additional operation costs, optimal backwashing is required. Another factor is sustainability: water utilities are showing increasing interest in exploring new sustainable GAC media. As these have different bed expansion tendencies due to different GAC characteristics with varying geometries, operational developments are needed for prediction models to estimate the expansion degree during backwashing. The prediction of the bed expansion of GAC is complex as the particles are non-spherical, porous and polydisperse. Through a combination of advanced particle laboratory and fluidisation experiments, we demonstrate a new approach which leads to an improved expansion prediction model for the backwashing of GAC filters. 相似文献
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44.
Herein, electro-responsive hydrogels were obtained by incorporation of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) into the gelatin methacryloyl (GelMA) by using photopolymerization technique. Hydrogels were characterized by FTIR and scanning electron microscopy analyses. Cytotoxicity tests were performed by L929 cell lines to determine cell compatibility. Swelling tests were conducted to investigate the water uptake capacity of hydrogels. 5-fluorouracil (5-FU) was selected as a model drug as it is known as a topical drug for some skin cancer type treatment. The release of 5-FU from the hydrogel was provided in efficient and controlled manner at simulated skin cancer (pH = 5.5) and under 0 and 1.5 V. The simulated drug delivery experiments conducted in vitro revealed that the drug releasing amount was higher when voltage is applied to the hydrogels. All results visualized that the obtained GelMA-based PEDOT/PSS hydrogels with enhanced electrical properties could be a potential candidate as an electrically sensitive drug carrier for treatment of skin cancer in the future applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46914. 相似文献
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46.
This study proposes a multiperiod mixed integer linear programming model for the management of a single municipal solid waste (MSW) treatment plant with sustainability as the objective. Discrete and continuous variables define the capacity selections for diverse MSW technologies, and the operation of the MSW network, respectively. The economic target is considered to maximize the net present value. The environmental impact is the minimization of a normalized environmental objective function (NEOF). The social target is the maximization of jobs. An interesting feature about the research work is the requirement of biodrying technologies for MSW moisture content control. Due to the conflicted nature among the sustainability components, a multiobjective optimization (MO) is carried out to find the Pareto optimal solutions. The MO results show that the Pareto optimal solutions vary around profit range of $4.9–8.5 billion, NEOF impact range of 3.2–3.6 units, and social benefit range of 2700–4828 jobs. 相似文献
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48.
Marcus Weyd Christian Pflieger Andy Vogel Hannes Richter Volker Prehn Christiane Günther Frank Splittgerber Alessa Gäbler Daniel Kaulbars Patrick Bräutigam Marcus Franke Samira Lambertz Julian Schlechtweg Ingolf Voigt 《化学,工程师,技术》2021,93(9):1432-1439
Reducing micropollutant pollution of water bodies is an important objective of water management and an integral part of environmental policy. Ceramic nanofiltration membranes were developed as multichannel membranes of increased membrane area and rotating disk filters. The membranes developed show retention of over 80 % for PEG 400. The membranes are currently being tested for the separation of micropollutants from wastewater contaminated with pharmaceuticals. With the help of a downstream oxidative process, the trace substances remaining in the permeate are degraded. 相似文献
49.
《Ceramics International》2022,48(17):24540-24549
In this study, we investigated the physical and chemical properties of H2 plasma-treated tin oxide (SnOX) thin films, followed by their applications in ambipolar thin-film transistors (TFTs). Finely controlled H2 implantation was carried out using a reactive-ion-etching system at a radio frequency power of 30 W and under various exposure times. H2 plasma treatments induced changes in the chemical structures and surface morphologies of the SnOX thin films, including a partial phase transformation of Sn and SnO to SnO2. The defects originating from oxygen vacancies (OVacs) in the SnOX thin films were passivated by H via the formation of Sn–H bonds, which decreased the density of subgap states in the SnOX thin films. The H2 plasma-treated SnOX TFTs showed considerably improved ambipolarity and electrical performance. Complementary metal–oxide–semiconductor (CMOS) logic inverters comprising H2-plasma-treated ambipolar SnOX TFTs exhibited a maximum gain of 34.5 V/V at a supply voltage of 10 V. The results of this study present the meaningful investigation of H2 plasma-treated ambipolar SnOX TFTs that can be used to fabricate CMOS circuits for various applications. 相似文献
50.
《Ceramics International》2022,48(18):26303-26311
In dental clinics, it is common to perform small fitting adjustments in dentures using a micro-grinding tool after testing them in the patient's mouth. This procedure increases local roughness and can lead to formation of microcracks on the prosthesis surface. This study aimed to investigate the benefits of a post-finishing heat treatment to surface roughness and crack healing and its effect on the flexural strength of lithium disilicate (LD) dental glass-ceramics. Commercially available lithium metasilicate, Li2SiO3, samples were heat treated at 840 °C for 7 min to induce the phase transformation into LD, Li2Si2O5. The LD samples were characterized by X-ray Diffraction, Scanning Electron Microscopy, Vickers hardness, Young’s modulus, and fracture toughness. One of the surfaces of the LD samples was sanded aiming to simulate the denture fitting adjustments performed in the dentist’s laboratory, generating a rough surface, Group 1. Half of the LD samples had their biaxial flexural strength evaluated by the piston-on-three-ball test (P–3B) and the other half were submitted to a second short-term heat treatment (840 °C - 5 min), Group 2, and later assessed by the P–3B. Roughness parameters in both groups were measured by 3D optical profilometry. After the crystallization heat treatment, formation of elongated LD crystals, Li2Si2O5, 35% amorphous phase, and residual Li3PO4 was observed. In addition, the following mechanical property values were obtained: Vickers hardness = 5.8 ± 0.1 GPa, fracture toughness = 2.2 ± 0.1 MPa m1/2, and Young’s modulus = 100.3 ± 0.3 GPa. The samples in Group 1 showed bending strength of 206 ± 30 MPa and the following roughness parameters: Ra = 0.45 ± 0.16 μm, Rz = 22.7 ± 6.7 μm, and PV = 27.7 ± 7.1 μm. In the samples in Group 2, the Ra, Rz and PV roughness parameters were 0.31 ± 0.12 μm, 5.2 ± 2.5 μm, and 9.2 ± 4.7 μm, respectively. With this decrease in roughness, the bending strength increased by 62%, with a mean value of 331 ± 59 MPa. In the need for machine finishing of LD-based glass-ceramic dental prostheses, the use of a second short-term heat treatment at 840 °C for 5 min generates considerable gains in bending strength, increasing the lifecycle of the prosthesis as a result of reduced surface roughness caused by softening of the remaining amorphous phase in the glass-ceramic. These conditions can be adapted to each chemical and crystallographic composition of the glass-ceramic under study. 相似文献