Waste treatment

废物处理
  • 文章类型: Journal Article
    低地球轨道以外的太空探索需要建立生物再生生命支持系统(BLSS),which,通过初级资源回收的生物过程,确保船员生存。然而,必须事先仔细评估在密闭空间生境中引入新生物的情况,以避免可能危及任务的意外事件。在这项工作中,我们设计并建造了一个试验室,命名为生长/饲养模块(GRM),完全隔离和配备微环境监测和控制系统。该单元专门用于研究单个生物过程,它可以组成设计功能BLSS。GRM可以通过特定的设备来实施,用于研究中的生物系统和控制环境参数,例如温度,湿度,湿度照明,如果需要,气体成分的压力。GRM在两种微绿培养的实验中都得到了验证,作为宇航员的新鲜食物来源,并饲养分解昆虫Hermetiaillucens以进行有机废物的生物转化。在每个生物过程的研究中,记录了环境和生物数据,允许对系统效率进行初步评估。GRM,作为一个完全封闭的环境,表示第一个自洽单元,允许微调最佳参数以实现不同生物过程的可操作性。此外,根据任务需要的可升级性和不同装备的模块的功能集成性是GRM多功能性的关键,代表BLSS设计的宝贵工具。
    Space exploration beyond the Low Earth Orbit requires the establishment of Bioregenerative Life Support Systems (BLSSs), which, through bioprocesses for primary resource recycling, ensure crew survival. However, the introduction of new organisms in confined space habitats must be carefully evaluated in advance to avoid unforeseen events that could compromise the mission. In this work, we have designed and built an experimental chamber, named Growing/Rearing Module (GRM), completely isolated and equipped with micro-environmental monitoring and control systems. This unit is specially intended for the study of single bioprocesses, which can be composed to design functional BLSSs. GRM can be implemented with specific devices for the biological system under study and the control of environmental parameters such as temperature, humidity, lighting and if required, pressure of gaseous components. GRM was validated in experiments of both microgreen cultivation, as a source of fresh food for astronauts, and rearing of the decomposer insect Hermetia illucens for bioconversion of organic waste. During the study of each bioprocess, the environmental and biological data were recorded, allowing to make preliminary assessments of the system efficiency. The GRM, as a completely confined environment, represents the first self-consistent unit that allows to fine-tune the optimal parameters for the operability of different bioprocesses. Furthermore, the upgradability according to the mission needs and the functional integrability of modules differently equipped are the keys to GRM versatility, representing a valuable tool for BLSSs\' design.
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  • 文章类型: Journal Article
    目的:已构思并建造了一种微生物燃料电池(MFC),用于处理羊粪废物并将其转化为清洁的可持续可再生能源。本研究的目的是检查这种生物电化学装置的性能,分解有机物(污染物去除)并同时发电。此外,目的是通过使用适当的放大系统来增强低电能。
    结果:所以,MFC运行10天,化学需氧量(COD)去除率提高了58.7%。然而,这项技术面临实际障碍,因为它产生低电能。因此,在这方面详细阐述了电源管理系统。它包括MFC,运算放大器(OA),太阳能光伏电池板和升压DC/DC转换器。因此,在通过太阳能光伏模块对其进行极化之前,使用OA显著增加了所获得的低电压输出。放大的电压足够,因此,用于馈送一个发光二极管。低输出电压0.5V是简单的收获,成功升压到大约2V(即4倍高),并最终作为电源。
    结论:MFCs关联成功地显示了正堆叠效应,当细胞并联连接时。这种新颖的应用对于利用废物中包含的天然生物能源来供应小型电子设备非常有趣。
    OBJECTIVE: A microbial fuel cell (MFC) has been conceived and constructed for the treatment of the sheep manure wastes and their conversion into clean sustainable renewable energy. The aim of the present investigation was to examine the performance of this bioelectrochemical device, in breaking down the organic matter (pollutant removal) and simultaneously producing electricity. Furthermore, the objective was to enhance the low electric energy by using an adequate amplification system.
    RESULTS: So, the chemical oxygen demand (COD) removal was increased by 58.7% with the MFC running for 10 days. However, this technology faces practical barriers as it produces low electrical energy. A power management system was therefore elaborated in this respect. It included the MFC, operational amplifier (OA), solar photovoltaic panel and a boost DC/DC converter. The low voltage output obtained was thus increased substantially using the OA prior to its polarization by the solar photovoltaic module. The amplified voltage was sufficiently enough and in consequence, utilized to feed a light emitting diode. The low output voltage 0.5 V was simply harvested, successfully boosted up to approximately 2 V (i.e. 4 times higher) and finally harnessed as a power supply.
    CONCLUSIONS: The MFCs association shows the positive stacking effect successfully, when the cells were connected in parallel. This novel application is very interesting to utilize the natural bioenergy contained in wastes to supply small electronic devices.
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  • 文章类型: Journal Article
    重复使用,recovery,由于各种经济和环境效益,鼓励回收报废车辆(ELV)。汽车再制造是一种特定的循环营销系统,用于回收零件的再利用,可以为拆解公司和消费者带来经济利益。本研究旨在揭示电力报废处理的经济和环境效益,混合动力车,传统乘用车。这项研究基于物料流分析(MFA)对ELV零件的再利用进行了经济评估,并对立陶宛市场上这些零件的价格进行了实际分析。使用MFA对ELV零件的再利用进行了环境评估,生产不同材料的二氧化碳当量,和生命周期评估方法。结果表明,38%的电动和混合动力车部件,以及27%和28%的柴油和汽油动力ELV零件,分别,可以出售(重复使用)。所有四种类型的ELV的经济利益可以为拆解者和乘用车消费者节省多达12,739欧元和51,281欧元。分别。最大的二氧化碳节约来自电动ELV部件的再利用,而最低的节省来自汽油ELV。
    Reuse, recovery, and recycling of end-of-life vehicles (ELVs) are encouraged owing to various economic and environmental benefits. Automotive remanufacturing serves as a specific circular marketing system for the reuse of recovered parts that can bring economic benefits for both dismantling companies and consumers. This study aimed to reveal the economic and environmental benefits of the end-of-life treatment of electric, hybrid, and conventional passenger cars. This research presents an economic assessment of the reuse of ELV parts based on a material flow analysis (MFA) and a practical analysis of the prices of these parts in the Lithuanian market. The environmental assessment of the reuse of ELV parts was performed using an MFA, the CO2 equivalents for the production of different materials, and a life cycle assessment methodology. The results showed that 38% of all electric and hybrid ELV parts, and 27% and 28% of diesel- and petrol-powered ELV parts, respectively, can be sold (reused). The economic benefit across all four types of ELVs could amount to savings of up to 12,739 Eur and 51,281 Eur for the dismantlers and passenger car consumers, respectively. The greatest CO2 savings result from reusing the parts of electric ELVs, whilst the lowest savings come from petrol ELVs.
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  • 文章类型: Journal Article
    Effective and efficient urban waste management systems (WMSs) are a cornerstone for a sustainable society. Life cycle costing (LCC) provides a useful framework for the joint analysis of economic and environmental impacts of a WMS, by considering both financial and external costs. The present study applies the methodology of societal LCC to the WMS of the Italian region of Emilia-Romagna to provide a case study on how the available information on waste flows and budget costs of a real WMS can be used to obtain an estimate of the total cost of waste management, including externalities. The results evidence that the main source of negative externality in the analyzed WMS is the transportation of waste, with only a minor role of external burdens due to incinerators and landfills. However, the positive externality resulting from recycling more than compensates those impacts, leading to a net external benefit associated to the WMS. The contribution of both uncertain unit external costs and environmental benefits imputable to recycled materials to the overall uncertainty of the result is systematically investigated by parametric uncertainty analysis. The most critical parameters in determining the sensitivity of the result are the monetary values attributed to primary energy consumption and CO2 emissions, together with assumptions on energy savings related to recycling. Eventually, it is shown how the developed LCC model can be used as decision-support tool to preliminarily investigate the implications of alternative management options on the financial and external costs of the WMS.
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  • 文章类型: Journal Article
    The amount and type of municipal solid waste (MSW) in Bahía Blanca (Argentina) were assessed and correlated with population socioeconomic level. In this sense, seven areas with different quality of life were selected. In addition, a parallel study on a control area was performed and validated for obtaining a representative result to provide analogous conclusions for the whole city. From this study, a combination of sorting methodologies is proposed in order to reduce the actual amount of waste sent to landfill. If these methodologies are implemented in Bahia Blanca city, MSW in landfill could be reduced at least 80%. The proposed strategy is to combine waste sorting at source and at destination. An alternative separation at source could be proposed as follows: packaging (including plastic, cans and Tetra Pak), other plastics, paper and glass. The rest of MSW could be included in a container which would be collected daily or three times a week without changing inhabitants\' habits and promoting their collaboration. Then, it could be separated at destination for waste-to-energy, composting, and biogas obtaining. Residuals from incinerators and biogas/composting plants would be sent to landfill. On the other hand, regarding the relationship between the proposed strategy and population quality of life, obtained results from this study could be useful to size and to efficiently locate disposal bins/containers for source separation as well as to redesign routes of municipal solid waste collection. Also, this strategy allows to add value to different components of MSW, improving working conditions of waste workers and creating new jobs in Bahia Blanca city.
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  • 文章类型: Journal Article
    Environmental efficiency (EE) was the efficiency that simultaneously targets economic benefits and environmental protection, requiring producers to provide higher levels of value under the premise of lower material and energy input and lower emissions. Waste treatment systems play an important place in the reduction of pathogen loading and then influence the environmental efficiency of farms. Based on a field study, take chemical oxygen demand (COD) and total nitrogen (TN) excretion as undesirable outputs, the paper aims to measure the EE considering the difference of waste treatment methods of sample pig farms. Technical efficiency (TE) and the contributing factors of environmental efficiency were also estimated. Results show that the environmental efficiency is significantly lower than technical efficiency. Years in the profession, manure treatment income, and receiving manure treatment subsidies had significant positive effects on environmental efficiency.
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  • 文章类型: Journal Article
    Since most plastics are not biodegradable, plastic recycling is the main part of global efforts to reduce plastic in the waste stream. Sorting of plastics imposes lots of difficulties which can be avoided by introducing plastic blends. This paper starts by reviewing the recent attempts to study plastic blends. Accordingly, the purpose of this study is to analyze experimental results and apply statistical measures using ANOVA to study the effect of increasing the waste ratio that contains both waste polystyrene and polypropylene on the mechanical properties of pure polystyrene when injected at different temperatures. Cost is taken as a response factor to analyze whether the degradation of mechanical properties is justified by a decrease in cost. As expected, cost dramatically decreases with increasing the waste ratio at any temperature. Increasing the waste ratio resulted in better mechanical properties with a maximum at a 30% waste ratio at 200 °C and 220 °C. This paper ends with a multi-objective optimization analysis that helps decision-makers optimize the properties needed of the studied plastic blend by controlling both the temperature and waste ratio.
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  • 文章类型: Journal Article
    工业塑料废物在环境中的积累是全球日益关注的问题。热化学工艺是处理塑料废物的首选方法,主要是因为它可以减少废物的体积;然而,塑料废物的热化学处理会排放有害的化学物质,如苯衍生物和多环碳氢化合物。为了克服这一挑战,负载型金属催化剂(碳载Pd和Pt催化剂)用于抑制聚对苯二甲酸乙二醇酯(PET)热解形成多环化合物和联苯衍生物。在Pd或Pt催化的PET热解过程中产生的多环化合物和联苯衍生物比非催化的PET热解少。在700°C下,Pt催化热解的多环化合物和联苯衍生物的浓度比非催化热解低107%和56%,分别。在400至800°C的温度下,Pt催化剂比Pd催化剂更有效地抑制PET热解过程中多环化合物和联苯衍生物的产生。这可能是因为Pt位点催化脱环反应和/或自由基机理,其在含碳物质如PET的热裂化中占主导地位。这项研究的结果将有助于通过热化学过程开发环境友好的工业塑料废物处理方法。
    The accumulation of industrial plastic waste in the environment is a global growing concern. Thermochemical process is a preferred method to dispose plastic waste mainly because it can reduce volume of the waste; however, the thermochemical disposal of plastic waste can emit harmful chemical species such as benzene derivatives and polycyclic hydrocarbons. As an effort to overcome this challenge, supported metal catalysts (carbon-supported Pd and Pt catalysts) were used to inhibit the formation of polycyclic compounds and biphenyl derivatives by pyrolysis of polyethylene terephthalate (PET). Less polycyclic compounds and biphenyl derivatives were generated during the Pd or Pt-catalyzed PET pyrolysis than non-catalytic PET pyrolysis. The concentrations of polycyclic compounds and biphenyl derivatives were 107 % and 56 % lower for the Pt-catalyzed pyrolysis at 700 °C than non-catalytic pyrolysis, respectively. The Pt catalyst was more effective to suppress the generation of polycyclic compounds and biphenyl derivatives during the PET pyrolysis than the Pd catalyst at temperatures from 400 to 800 °C. This was likely because the Pt sites catalyzes decyclization reaction and/or free radical mechanism that is dominant in thermal cracking of carbonaceous substances such as PET. The results of this study would help develop environmentally friendly industrial plastic waste treatment methods via thermochemical processes.
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  • 文章类型: Journal Article
    Etoposide is an antineoplastic agent used for treating lung cancer, testicular cancer, breast cancer, pediatric cancers, and lymphomas. It is a pollutant due to its mutagenic and carcinogenic potential. Disposal of waste from this drug is still insufficiently safe, and there is no appropriate waste treatment. Therefore, it is important to use advanced oxidative processes (AOPs) for the treatment and disposal of medicines like this. The use of strontium stannate (SrSnO3) as a catalyst in heterogeneous photocatalysis reactions has emerged as an alternative for the removal of organic pollutants. In our study, SrSnO3 was synthesized by the combustion method and characterized by X-ray diffraction (XRD), Raman, UV-Vis, and scanning electron microscopy (SEM) techniques, obtaining a surface area of 3.28 m2 g-1 with cubic and well-organized crystallinity and a band gap of 4.06 eV. The experimental conditions optimized for degradation of an etoposide solution (0.4 mg L-1) were pH 5 and catalyst concentration of 1 g L-1. The results showed that the degradation processes using SrSnO3 combined with H2O2 (0.338 mol L-1) obtained total organic carbon removal from the etoposide solution, 97.98% (± 4.03 × 10-3), compared with TiO2, which obtained a mineralization rate of 72.41% (± 6.95 × 10-3). After photodegradation, the degraded solution showed no toxicity to zebrafish embryos through embryotoxicity test (OECD, 236), and no genotoxicity using comet assay and micronucleus test.
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  • 文章类型: Journal Article
    The numerous ecological problems caused by the accumulation of secondary aluminum dross (SAD) as a hazardous waste generated in aluminum castings have necessitated a need for a sustainable recycling solution. This study proposes a novel and green leaching-based process for recovery of nano-alumina as a highly valuable material from SAD. The leaching phase was performed at atmospheric pressure and low temperature. To obtain optimum conditions for the recovery process, the dissolution kinetics and mechanism of SAD in hydrochloric acid were initially studied under a given liquid-to-solid ratio of 20 ml/g, various reaction temperatures and times. It was found that the dissolution of SAD in HCl was controlled by layer diffusion with an apparent activation energy of around 10.49 kJ/mol. Alumina in the form of a high purity nanostructured powder from SAD was then recovered under optimum conditions of 85 °C, acid concentration of 5 mol/l, and reaction time of 120 min by the proposed process. Characterization of nano-alumina was performed using X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDAX), and transmission electron microscopy (TEM) techniques. The results revealed that the as-produced alumina had a nano-crystalline structure, having the crystal size of 15.90 nm and consisting mainly of gamma phase. The microstructural studies disclosed the aggregations of rounded-corner shaped particles. Also, wet chemical analysis showed a purity of more than 98% for the produced alumina.
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