Arsenic-alkali residue is a hazardous waste produced by the refining process of crude antimony in antimony smelting, and contains highly toxic sodium arsenate and a large number of residual alkali. ...In this study, aiming at the problems of the low recoveries and incomplete separation of arsenic and alkali, the secondary pollution of arsenic-alkali mixed salts and the insufficient utilization of valuable resources in the treatment process of arsenic-alkali residue, a new process of antimony enrichment with water leaching, twice alkali recovery with CO2, selenium recovery with acidification and arsenic recovery with SO2 reduction and evaporation concentration was proposed to dispose arsenic-alkali residue. The results showed that the leaching efficiencies of Sb, As, Se and alkali in arsenic-alkali residue were 1.8, 98.4, 97.9 and 100% by hot water leaching, respectively. Alkali was recovered with CO2 from arsenic-alkali solution and the direct recovery was 87.8%. In addition, the purity of Na2CO3 product was higher than 90% and As content in product was controlled below 0.2%. Deep alkali removal and efficient selenium recovery were achieved by acidification from the solution after alkali recovery, the direct recovery of Se was 80.6%, and the purity of crude selenium was 81.7%. Arsenic was recovered from the solution after selenium removal and the direct recovery was 79.4%, and the quality of As2O3 product reached the third grade standard of arsenic trioxide (GB 26721-2011). This process realizes the efficient recovery of alkali, selenium and arsenic in arsenic-alkali residue, and also does not produce arsenic-alkali mixed salts and wastewater.
•A new process was proposed to dispose antimony smelting arsenic-alkali residue.•The efficient recovery of alkali, selenium and arsenic was achieved.•Se was recovered in the form of elemental selenium without adding reducing agent.•The recycling process is clean and environmentally friendly.
Age-related macular degeneration (AMD) is a complex eye disease with many pathogenesis factors, including defective cellular waste management in retinal pigment epithelium (RPE). Main cellular waste ...in AMD are: all-trans retinal, drusen and lipofuscin, containing unfolded, damaged and unneeded proteins, which are degraded and recycled in RPE cells by two main machineries-the ubiquitin-proteasome system (UPS) and autophagy. Recent findings show that these systems can act together with a significant role of the EI24 (etoposide-induced protein 2.4 homolog) ubiquitin ligase in their action. On the other hand, E3 ligases are essential in both systems, but E3 is degraded by autophagy. The interplay between UPS and autophagy was targeted in several diseases, including Alzheimer disease. Therefore, cellular waste clearing in AMD should be considered in the context of such interplay rather than either of these systems singly. Aging and oxidative stress, two major AMD risk factors, reduce both UPS and autophagy. In conclusion, molecular mechanisms of UPS and autophagy can be considered as a target in AMD prevention and therapeutic perspective. Further work is needed to identify molecules and effects important for the coordination of action of these two cellular waste management systems.
Accelerator-based techniques are considered among the leading methods to produce radioactive nuclei. The ISOLDE facility (Isotope mass Separator On-Line DEvice) at the European Organization for ...Nuclear Research (CERN) is a unique source of beams of radioactive nuclides that are used in a wide range of research domains, from nuclear astrophysics to life sciences. Over 400 ISOLDE targets are currently stored at CERN and an average of 30 targets are irradiated every year. All these targets are planned to be dismantled and disposed of as radioactive waste in a dedicated repository in Switzerland. This paper provides an overview of the challenges related to the radionuclide activity predictions, the number of activation scenarios, dismantling and conditioning of the Radioactive Waste (RW) using a hot cell (HC), the high dose rate, uncertainties related to unknown geometry parameters of the RW packages, and finally industrializing a complex RW elimination process as ITEP for an accelerator complex. The performed work addresses each of these challenges and offers technical solutions based on state-of-the-art computational codes, statistical techniques, and state of art Non-Destructive Assay (NDA) techniques using high energy-resolution gamma spectrometry. The methodology followed can be of guidance for the development of similar processes at other facilities.
Photocatalysis appears to be an appealing approach for environmental remediation including pollutants degradation in water, air, and/or soil, due to the utilization of renewable and sustainable ...source of energy, i.e., solar energy. However, their broad applications remain lagging due to the challenges in pollutant degradation efficiency, large-scale catalyst production, and stability. In recent decades, massive efforts have been devoted to advance the photocatalysis technology for improved environmental remediation. In this review, the latest progress in this aspect is overviewed, particularly, the strategies for improved light sensitivity, charge separation, and hybrid approaches. We also emphasize the low efficiency and poor stability issues with the current photocatalytic systems. Finally, we provide future suggestions to further enhance the photocatalyst performance and lower its large-scale production cost. This review aims to provide valuable insights into the fundamental science and technical engineering of photocatalysis in environmental remediation.
This review highlights the recent advancement in state-of-the-art strategies for improvement of semiconductor photocatalysts for environmental remediation. Display omitted
•This review highlights principles and reaction mechanisms of environmental photocatalysis.•Further, it highlights the effect of pollutants on living organisms and their removal from environment.•Various modification strategies for solar light absorption and charge separation are discussed.•Efficiency and stability issues of the photocatalysts and their possible solutions are discussed.
In Malaysia, palm oil mill (POM) retrofit towards pollution control is vital to receive mandatory certification. Resource, waste, energy and water integrations could be performed between POM, palm ...oil refinery (POR) and conventional heat and power plant (CHP) under different owners to form a sustainable integrated palm oil-based complex (POBC). A cooperative game context is applied where multi-owner POM, POR and CHP act as multiple “players” in the POBC “game”. This study presents a systematic optimisation framework to design a sustainable multi-owner POBC. Firstly, five objectives related to economic, environmental and energy potentials are balanced using fuzzy optimisation approach to yield multi-objective optimal POBCs under four facility construction scenarios. Subsequently, profit-cost allocation within the multi-owner POBC is performed via an integrated cooperative game-based approach. The four fuzzy optimal POME-eliminated POBCs achieved economic potentials at 39.71 × 106- 40.84 × 106 USD/y with maximum λ (0.652). The profit-cost allocation results show economic potential improvements at 0.12 × 106- 0.46 × 106 USD/y for the multi-owner POBC facilities. POM is the major GP receiver whereas CHP benefits the most from POBC collaboration. The optimal multi-owner POBCs are economically feasible upon decision-makers' interest and robust against investment cost variations. The increment in Feed-in Tariff and biomass-based steam price reduces the economic stability of multi-owner POBC.
•Optimal design for sustainable multi-owner integrated palm oil-based complex (POBC).•Profit-cost allocation based on cooperative game model and stability constraint.•Four fuzzy optimal POBCs with economic potential from 39.71 × 106 to 40.84 × 106 USD/y.•Economic feasible and robust multi-owner POBC against investment cost variations.•Electricity and steam price increments reduce the stability of multi-owner POBC.
LEAN System Management in Hospitals Bošnjak, Ivan; Bošnjak, Marija
Athens Journal of Health and Medical Sciences,
09/2020, Letnik:
7, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Statement of problem: Healthcare industry is struggling under an increasing pressure of constantly rising costs as the science opens new horizons in the development of new drugs and technologies ...making thus the task of employing resources in an effective manner more challenging than ever before. LEAN system management in hospitals can contribute to effective costs management and better results. We analyzed industrial LEAN model management and its implementation in hospitals. LEAN management has its roots in Just-In- time management implemented by the company Toyota that has provided for this company to become a fierce competitor to the United States car industry. The aim of LEAN is to eliminate waste and reduce production time. The basic principle of LEAN philosophy is to determine where the value is added in the process and where it is not. LEAN consists of several tools: five S, Kaizen events, standardized work, kanbans, spaghetti diagrams. Spaghetti diagrams are used to track the movement of employees, materials and patients. Effective implementation can reduce the time used for different needs of patients and tasks of employees, so this is an example of lost effectiveness that can be eliminated. Kaizen events include a project team selected from hospital staff, whose goal is to solve efficacy problem by defining the problem and reasonable output and then implement new ideas. An example may be a disorganized inventory of hospital pharmacy that consequently prolongs the time of drug delivery. The project team can locate the problem and suggest inventory changes. Competitive market companies must constantly innovate and implement new ideas to win a market share. Such innovations can sometimes be used in healthcare industry, and effective implementation can increase the quality of health service provided by hospitals, and also reduce never ending rising costs, a challenge that hospital management encounters.
While the deposit qualities for mineral raw materials are constantly decreasing, the challenges for sustainable raw material processing are increasing. This applies not only to the demand for ...minimizing the consumption of energy, water, and reagents, but also to the reduction of residual materials, especially fine and difficult-to-landfill materials. Sensor-based ore sorting can be used as a separation process for coarser grain sizes before the application of fine comminution and separation technologies and is applicable for a large variety of mineral raw materials. Sensor-based ore sorting applies at various points in the process flow diagram and is suitable for waste elimination, for material diversion into different process lines, for the production of pre- and final concentrates, as well as for the reprocessing of coarse-grained waste dumps and other applications. The article gives an overview of the development and state of the art of sensor-based ore sorting for mineral raw materials and introduces various applications.
This study investigates using Sulfur-Free Lignin (SFL) as a stabilizer to reinforce soil for civil engineering construction. To comprehensively evaluate the engineering performance of SFL stabilized ...soil, 3, 7, 10, 12 and 15% mixtures were tested and the influence of climate factors (assessed subjecting the soil to different freeze-thaw cycles) was also considered. The experimental program investigated mechanical strength (unconfined compressive strength) and physicochemical properties, which included grain size distribution, Atterberg limits, variation of elemental and mineral composition, pH, cation exchange capacity, X-ray diffraction/fluorescence and thermal conductivity. In addition, micro-characterization through SEM and pore size distribution was also performed. A considerable improvement of the mechanical properties was observed, which increases with SFL content up to 12%. This was based on changes in the physical and not chemical properties, hinting that the stabilization mechanism consists in physical binding unlike for traditional soil stabilizers. Moreover, it was found that SFL addition improved frost resistance. Based on these results, utilizing SFL as a soil stabilizer for application in earthworks shows great potential and would promote the bio-ethanol industry and engineering construction to be more sustainable and greener, particularly because it does not risk inducing soil pH contamination unlike traditional chemical agents.
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•The mechanical strength of SFL stabilized soil shows a significant improvement from 244 kPa up to 1159 kPa.•Unlike traditional chemical stabilizers, SFL does not lead to a risk of soil pH contamination.•The SFL-stabilized soil still shows a satisfactory mechanical performance after suffering high numbers F-T cycles.•The stabilization mechanism of SFL is physical binding rather than chemical reactions.•According to SEM and MIP tests, the F-T cycles mainly cause physical damages in SFL stabilized soil.
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