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1.
Waste Manag ; 116: 1-8, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32781407

RESUMO

Investigations of stabilized/solidified sediment (S/S sediment) by simulated field-construction processes (crushing and filling) are fundamental to evaluating the potential reuse as fill materials. A series of tests were conducted on the samples prepared from S/S sediment grains (SG), which was obtained by crushing the cement treated sediment. By sampling the SG with different field-curing durations (t1: 28, 35, 56 and 98 days) and measuring them by unconfined compressive strength (UCS) tests, the effect of t1 on the UCS was investigated. By continually curing the samples prepared from the SG with 28 field-curing days in laboratory for an additional 7, 28, 35 and 70 days (t2) and subjecting them to UCS and tank leaching tests with different ambient (leachate) pH values (1, 4, 7, 10 and 14), the effect of t2 and ambient pH was evaluated. Increasing t1 and t2 was found to significantly influence the strength of SG, which highlights the importance of an appropriate curing period. The releases of the metals (As, Cr, Cu, Zn, Pb, Ni, and Hg) in the SG exhibited a strongly pH-dependence but less correlation with t2. Neutral conditions (pH = 7) offered the best immobilization capacity for Cu; As, Cr, Ni and Zn exhibited the lowest release at pH = 10; the release of Pb decreased moderately with increasing pH. The S/S sediment complied with the acceptance criteria in terms of metal release and can be regarded as an environmentally friendly fill material. The results highlight the technical feasibility of stabilized sediment recycling in aquatic environment projects.


Assuntos
Metais Pesados/análise , China , Materiais de Construção , Lagos , Reciclagem
2.
Waste Manag ; 116: 79-90, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32791461

RESUMO

Despite pressing attention on construction waste management (CWM) issues, low rates of construction waste (CW) reuse and recycling (R&R) remain a limitation in construction projects. In recent years, Building Information Modeling (BIM) has gained momentum for CWM purposes; its data-richness, visualization, and simulation capabilities provide an opportunity to enhance CW R&R planning at the project level. In this context, this study proposes temporal-based algorithms integrated with 4D-BIM for the planning of concrete and drywall waste R&R throughout construction projects. Two case studies from Central Texas were used for the demonstration of the algorithms, and estimates were validated with ground truth data and literature values from different projects in North America. The overarching objective of the proposed algorithms is to streamline estimation and visual planning of CW for on-site reuse, and off-site recycling - therefore promoting a more proactive and schedule-based CWM plan. In addition, the approach improves team communication around CWM goals of the project. Moreover, through the use of 4D-BIM, on-site waste reuse opportunities are planned in advance, thus, improving resource recovery and minimizing waste disposal in landfills.


Assuntos
Materiais de Construção , Gerenciamento de Resíduos , Reciclagem , Texas , Instalações de Eliminação de Resíduos
3.
Waste Manag ; 116: 131-139, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32799094

RESUMO

Waste tire rubber is produced on a large scale in the automotive industry and is considered difficult to recycle because they have iron, nylon, polyester, and chemical structure formed by cross-links. In this way, the waste is almost always deposited in inappropriate places or incorrectly burned, causing a series of environmental problems. The objective of this work was to analyze the viability of the use of waste tire rubber (5, 10, and 20% m/m) reinforced in polyurethane foam (PU) derived from castor oil to obtain composites, as an alternative for raw materials petrochemical industrial. The materials were characterized by scanning electron microscopy (SEM), optical microscopy (OM), apparent density, contact angle, water absorption, X-ray diffractometry (XRD), spectroscopy infrared (FTIR), thermogravimetry (TGA) techniques, and mechanical tests. The results showed that the residue of the rubber powder reinforced with polyurethane caused an increase in the density of the composites when compared to pure PU, which directly influenced the morphological, physical, thermal, and mechanical properties. This fact occurred because with the insertion of rubber powder in the PU there was a decrease in cell size and increase of pore volume. The TG and DTG analyzes showed that the insertion of the rubber powder improved the thermal stability of the composite when compared to pure PU, as well as impact tests and contact angle.


Assuntos
Óleo de Rícino , Poliuretanos , Reciclagem , Borracha , Termogravimetria
4.
Waste Manag ; 116: 140-146, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32799095

RESUMO

Integrated gasification combined cycle (IGCC) is a highly efficient method for producing electricity but discharges a byproduct in the form of a glassy slag, similar to other electricity generation operations. Several technologies for recycling IGCC slag have been developed thus far, although the results obtained are not promising or universally applicable. We quantitatively characterized an IGCC slag by using various testing methods, including an automated scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) system, to recognize its potential for recycling. The IGCC slag did not contain free CaO, and the absence of free lime would address a concern of volumetric expansion during hydration. Automated SEM-EDS analysis revealed that approximately 98% of the IGCC slag particles consisted of calcium-rich aluminosilicate materials. Obvious differences in the concentrations of Si, Al, and Ca between the amorphous phases and the average chemical bulk were recognized. The chemical composition of the amorphous Si-Al-Ca phases was similar to that of Class C fly ash, while the average bulk composition of the IGCC slag was in between that of Class C and Class F fly ashes. Considering this discrepancy, understanding the dissolution mechanism of the reactive amorphous fraction as well as an exact assessment of the reaction products based on the role of Ca in alkali-activated materials provides a new approach for the valorization of IGCC slag.


Assuntos
Cinza de Carvão , Reciclagem , Microscopia Eletrônica de Varredura
5.
J Environ Manage ; 273: 111154, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32771852

RESUMO

The frequent environment-unfriendly treatments of agro-industrial bio-wastes cause severe pollution through air pollution and through residual effluents and hazardous solid waste. These bio-wastes can contain phenolic compounds, forms of phenolic acids and flavonoids in plants. They are however the most abundant class of many phytochemicals and have been given great interest due to their health advantage and high economic value. An interesting upgrading of these bio-wastes may consist in obtaining a concentrated extract of phenolic compounds using no-toxic solvents, hence protecting the environment and human health. In this work, different alternatives of the extraction process were evaluated using an exergetic analysis. The energy and water consumptions, CO2 emissions, exergetic yield, wasted and destroyed exergy were calculated. It was found that several alternatives for recycle streams were convenient (streams with higher chemical exergy were not discharged into the environment). The energy and water consumption for the best alternative (ethanol-water ratio 1/1 including recycle stream, named E-W 1/1 Rec) were 567 MJ/h and 105 kg/h, respectively and the CO2 emission was 105 kg/h. The calculated exergy destruction indicated that the evaporation and distillation stages may be optimized towards a more sustainable operation. It is not advisable to dry the bio-waste if it will be immediately processed once generated.


Assuntos
Poluição do Ar , Resíduos Industriais , Flavonoides , Humanos , Fenóis , Reciclagem
6.
Waste Manag ; 117: 32-41, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32805599

RESUMO

This study conducted a survey at 15 building construction and demolition sites in Hanoi, Vietnam in order to identify waste generation rates (WGR), composition, and current handling practices of construction and demolition waste (CDW). Waste quantification based on CDW layout, image analysis to identify CDW components, and face-to-face interviews with construction and demolition contractors to reveal CDW flows were performed. WGRs of 79.3 kg/m2 and 1,030 kg/m2 were determined in small- and large-scale construction sites, respectively, whilst WGRs at small and large demolition sites were 610 kg/m2 and 318 kg/m2. The composition analysis identified soil, concrete, and brick as the major CDW components, consistent with building structures in Vietnam. The interviews discovered that merely 10% of total CDW flows was from recycled and reused CDW. Reuse and recycling rates were most significant for metal and were lower (in descending order) for brick, concrete, and soil. These findings raise a need for aggressive and integrated strategies to promote more sustainable CDW management in the country, including the development of recycled CDW product standards, policies that facilitate recycling, and more importantly, a sustainable business model for CDW recycling, for which future evaluations of economic feasibility are of great importance.


Assuntos
Indústria da Construção , Gerenciamento de Resíduos , Materiais de Construção , Resíduos Industriais/análise , Reciclagem , Vietnã
7.
Waste Manag ; 117: 48-57, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32805601

RESUMO

We present, rapid and efficient identification of ten different types of post-consumer plastics obtained from a local recycling unit by deploying a low cost, compact CCD spectrometer in laser-induced breakdown spectroscopy (LIBS) technique. For this investigation, spectral emissions were collected by an Echelle spectrograph equipped with an intensified charge-coupled device (ES-ICCD) as well as a non-gated Czerny Turner CCD spectrometer (NCT-CCD). The performance is evaluated by interrogating the samples in a single-shot as well as accumulation mode (ten consecutive laser shots). The results from principal component analysis (PCA) have shown excellent discrimination. Further, the artificial neural network (ANN) analysis has demonstrated that individual identification accuracies/rates up to ~99 % can be achieved. The data acquired with ES-ICCD in the accumulation of ten shots have shown average identification accuracies ~97 %. Nevertheless, similar performance is achieved with the NCT-CCD spectrometer even in a single shot acquisition which reduces the overall analysis time by a factor of ~15 times compared to the ES-ICCD. Furthermore, the detector/collection system size, weight, and cost also can be reduced by ~10 times by employing a NCT-CCD spectrometer. The results have the potential in realizing a compact and low-cost LIBS system for the rapid identification of plastics with higher accuracies for the real-time application.


Assuntos
Lasers , Plásticos , Análise de Componente Principal , Reciclagem , Análise Espectral
8.
Waste Manag ; 117: 9-17, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32805603

RESUMO

One of the current challenges in circular economy is the ability to transform waste into valuable products. In this work, waste of electrical and electronic equipment (WEEE) was used as a gold source to prepare stable gold nanoparticles (AuNP). The proposed methodology involves a series of physical and chemical separation steps, carefully designed according to the complex nature of the selected WEEE and the targeted product. In a first step, pins from microprocessors were separated by mechanical treatments, allowing to concentrate gold in a metallic fraction. A two-step hydrometallurgical method was subsequently performed, to obtain a Au (III) enriched solution. Such solution was used as a secondary raw material to obtain AuNP. For that purpose, a specific synthetic method was developed, adapted to the high acidity and ionic strength of the solution. Thanks to the use of two easily available reducing agents (sodium citrate and ascorbic acid) and a polymeric stabilizer (PVP), it was possible to obtain high purity AuNP presenting a mixture of well-defined spherical and triangular shapes. These AuNP were finally deposited onto glass substrates and present a sensitive response to refractive index changes in the environment, a necessary condition towards application in optical sensors. In summary, this upcycling case study demonstrates that e-waste can successfully replace primary raw materials to obtain highly valuable and useful nanomaterials. These results highlight the potential of urban mining as a sustainable and circular approach to the development of nanotechnologies.


Assuntos
Resíduo Eletrônico/análise , Nanopartículas Metálicas , Ouro , Reciclagem , Substâncias Redutoras
9.
Waste Manag ; 117: 81-92, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32818811

RESUMO

China's automobile industry is developing rapidly, but the recycling rate of end-of-life vehicles has been low. In 2018, the recovery rate of end-of-life passenger vehicles was less than 18% of the scrapped amount. Dynamic material flow analysis can predict the amount of end-of-life passenger cars in China in the future, and analyze the flow of materials in recycling system. Life cycle assessment can be used to quantify greenhouse gas emissions. Therefore, this paper integrates these two methods into the model construction of recycling decision system. Meanwhile, sensitivity analysis of the important factors affecting the efficiency of the recovery system is carried out. Finally, the main recovery indexes of the system are predicted under three scenarios: low-speed, medium speed and high-speed development, which are set based on scrap volume, standard recovery rate, proportion of assembly into remanufacturing and carbon tax price. The research results show that in 2018, 656.9 kg/vehicle of iron, 150.2 kg/vehicle of aluminum and 7.9 kg/vehicle of copper are recovered from end-of-life passenger car in China, and the carbon emission during the recovery process is 651.1 kg of CO2eq/vehicle, with a total emission reduction of 3816.1 kgCO2eq/vehicle compared with the original production, and the economic benefit is about 5055.5 yuan/vehicle. The scenario prediction results show that by 2050, from the low-speed development scenario to the high-speed development scenario, the total amount of iron, aluminum and copper recovered rise from 3.96 million tons, 915 thousand tons and 46 thousand tons to 697 thousand tons, 1.61 million tons and 80 thousand tons respectively throughout the year. The carbon emission in the recovery process rise from 4.98 thousand tons to 9.32 million tons. Compared with the original production, the carbon emission reduction increases from 2.21 million tons to 38.3 million tons, the economic benefit increases from 58.9 billion yuan to 118.8 billion yuan, and the comprehensive benefit increases from 57 billion yuan to 111.6 billion yuan.


Assuntos
Gases de Efeito Estufa , Reciclagem , Automóveis , China , Indústrias
10.
J Environ Manage ; 273: 111063, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32861149

RESUMO

Strict environmental regulations as well as requirement of conservation of natural resources compelled the researchers to recycle the metal values from secondary resources. The scrap magnets found to be a potential alternative resource to extract rare earth metal, Nd. Present paper reports a novel process flow-sheet for the recycling of scrap Nd-Fe-B magnets to recover Nd as marketable salt and other valuable by-products. The Nd-Fe-B magnets were demagnetized, crushed and charged to atmospheric leaching resulting in ~99.99% recovery of REMs (Nd, Pr, Dy) and Fe using 1 M H2SO4 solution at room temperature for 90 min and pulp density 50 g/L. The obtained leach liquor was subjected to acid extraction procedure by mixing the liquor with 70% TEHA diluted in kerosene for 10 min, which requires five stages for complete extraction of acid from the liquor having O/A ratio 2:1. Ammonia solution was used to increase the pH of acid free leach liquor to 1.65 for the precipitation of Nd (with minor amount of Pr and Dy) and above that to precipitate Fe. Further, processing of these valuables make them industrially applicable. The leached residue was checked using Toxicity Characteristics Leachability Procedure (TCLP) test and found the remained metals within the permissible limit. This process offers a simple and efficient means to reduce the toxicological effect by recovering Nd from magnets of computer hard disks.


Assuntos
Metais Terras Raras , Neodímio , Imãs , Metais , Reciclagem
11.
J Environ Manage ; 271: 111010, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778294

RESUMO

Increasing urbanization and rapid depletion of resources have forced authorities to shift from traditional linear system of take-make-use-dispose to circular system of resource conservation. Circular Economy (CE) is a sustainable development approach that works on the waste management strategy of reduce, reuse, recycle, and recover. Considerable work has been performed on CE in various sectors such as in electronic sector, construction sector, automotive sector, etc. However, CE in the water sector is gaining rapid attention, because of imbalance in water resources and the prevailing linear approach. The aim of this study is to review the world-wide growth of CE concept in the water sector from an economic, environmental, social, and technical perspective. 98 publications were selected by systematic literature review and categorized in economic, environmental, social, and technical criteria including a combination of multiple criteria. In this study, the world-wide status of CE implementation in the water sector is assessed and strategies to encourage and enhance CE implementation are proposed. The six BS8001:2017 principles and 6Rs (reduce, reuse, recycle, reclaim, recover, restore) of waste management are critically analyzed for deriving recommendations and successful implementation of CE in water sector. Finally, challenges and opportunities to implement CE in the water sector in India are discussed.


Assuntos
Gerenciamento de Resíduos , Água , Índia , Reciclagem , Recursos Hídricos
12.
J Environ Manage ; 271: 110988, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778280

RESUMO

Although the food service sector is a major user of water, the potential for heat recovery from commercial kitchens' drain water remains largely unexplored. For the first time, we compare the life cycle environmental burdens of producing and installing a heat recovery system with the environmental credits arising from energy savings for a restaurant case study, and for the entire UK food service sector. Life Cycle Assessment was applied to determine the impacts of heat recovery systems made from different materials and comprising a heat exchanger in the shape of a concentric double-walled pipe, pipework and fittings. The design option with the smallest environmental footprint combined a heat exchanger made out of polypropylene-graphite (PP-GR) with polyethylene pipework, exhibiting 80-99% less environmental impact compared with components made out of (35% recycled) copper. Contrasting the environmental impacts of two heat recovery set-ups with energy savings shows that a PP-GR based system pays back all burdens of the seven assessed environmental impact categories, within two years, while payback times for the copper-based system vary depending on the replaced energy source, and can exceed the 10 year operational lifetime of the system. When looking at typical flow-rates in UK food outlets, net environmental savings can be realised across all analysed impact categories above a threshold water consumption of 555 L/day, using current technology. Extrapolation to the UK food service sector indicates annual greenhouse gas emission mitigation potential of about 500 Gg CO2 equivalent.


Assuntos
Gases de Efeito Estufa , Gerenciamento de Resíduos , Fontes Geradoras de Energia , Efeito Estufa , Temperatura Alta , Reciclagem
13.
J Environ Manage ; 271: 111031, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778311

RESUMO

Generally, the mechanical strength and stiffness of old corrugated cardboard (OCC) waste paper are decreased after multiple recycling procedures. Surface sizing starch, which is extensively used in the surface sizing of paper making, accumulates after dissolving from the fibers and is transformed into pollutant during the OCC re-pulping process. To overcome the pollution and reutilization problem of the waste starch during the recycling process of OCC paper, waste starch was ionized using hydrogen peroxide (H2O2) to improve the mechanical properties of OCC paper during the reutilization. The results showed that the carboxyl group of waste starch increased with an increasing degree of ionization, resulting in enhanced copper ion adsorption capacity. Furthermore, the retention rate of the modified starch in the wet-end increased from 18.0% to 48.2%. The OCC paper presented the highest burst index and tensile strength of 8.94 kPa m2/g and 112.5 N m/g, respectively, when MS-2 was added. This work has great significance for implementation of the cleaning production of OCC waste papers and the reutilization of the waste starch.


Assuntos
Peróxido de Hidrogênio , Amido , Papel , Reciclagem , Resistência à Tração
15.
Water Sci Technol ; 81(11): 2441-2449, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32784287

RESUMO

Municipal sludge disposal and recycle has become a prominent research theme. In this study, a sequential process for integral treatment of municipal sludge was primarily presented, combining acid leaching, anion exchange and aerobic composting. The aim of the process was to remove chromium (Cr) from the sludge and reuse the sludge as manure. Firstly, Cr was removed from municipal sludge via the acid leaching process; the removal rate was up to 57.43%. Then, ion exchange resin was used to remove Cr from leachate; the removal rate reached 95%. Aluminum sheet was used to replace the Cr from eluent; the replacement rate was 63.3%. The aerobic composting process could be successfully warmed up to above 55 °C and lasted for 4 days; the seed germination index reached 68.3%. After the composting process, the residual Cr in sludge mainly existed at a more stable residual state and organic binding state. Overall, this novel sequential process serves as a potential high-efficiency, green, low-energy way for municipal sludge recycle.


Assuntos
Compostagem , Ânions , Esterco , Reciclagem , Esgotos
16.
Waste Manag ; 115: 113-120, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32736031

RESUMO

Liberation and reduction of cathode material are the necessary procedures for improving the recycling efficiency of cathode material derived from spent lithium-ion batteries. In this research work, a pyrolysis technology was utilized to remove the organic binder and enhance liberation of electrode materials. At the same time, pyrolysis treatment can facilitate the thermal-reduction of Co3+ in LiCoO2 to Co2+ with surface organics, which lays a foundation for the subsequent reductant-free acid leaching. Results indicate that the crystal structure of pure LiCoO2 is not changed at a pyrolysis temperature of 600 °C, but LiCoO2 transforms to CoO, Li2CO3, LiF, and Li2O under the reduction action of HF, pyrolytic carbon, and additive carbon black. Water-impact crushing is synchronized with water-leaching to separate electrode materials from aluminum foil and recover Li element. Afterwards, reductant-free acid leaching technology can be utilized to recycle Li and Co from spent LiCoO2 batteries. Recovery efficiency of Li element in water-leaching process was up to 92.17% while the remaining 7.83% of Li and all Co elements were recovered during reductant-free acid leaching process. Based on the foundation analysis, the green chemical process for recovering valuable metals from spent lithium-ion batteries was proposed.


Assuntos
Fontes de Energia Elétrica , Lítio , Eletrodos , Metalurgia , Reciclagem
17.
Ecotoxicol Environ Saf ; 202: 110893, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615495

RESUMO

Leaching of the hazardous electric arc furnace (EAF) dust containing mainly zinc ferrite and zinc oxide, accompanied by minor concentrations of arsenic compounds, was investigated using sulfuric acid. In order to reach the maximum recovery of zinc, the leaching solution was adjusted to recover both iron and zinc at their maximum possible values. To obtain a high recovery value of zinc and iron, analyzed by AAS, the optimum leaching condition was found to be the temperature of 90 °C, the sulfuric acid concentration of 3 M, the particle size of 75 µm, the S/L ratio of 1:10 g/mL and the leaching time of 2 h. The percentages of the zinc and iron recovery under the optimum condition were ca. 98.6% and 99.1% respectively, which were verified by a confirmation test and were very close to the predicted values of 100% based on the optimized model, obtained through the software. From the thermodynamics' point of view, it has been found that Zn2+ is the predominant species (90%) under the leaching condition applied. Moreover, the predominant species of iron are FeSO4+, FeHSO42+, Fe(SO4)2- and Fe3+ in the magnitudes of 65.8%, 25.6%, 4.4% and 4.0%, respectively. According to the kinetic results, the controlling step in the leaching was the chemical reaction at the most of the operating temperatures and times. In order to purify the zinc solution for electrowinning, iron and arsenic were removed through the jarosite formation process as confirmed by the XRD results. The speciation of arsenic in the precipitated jarosite was explored by XPS. Finally, the low concentrations of arsenic (less than 0.1 ppm) and iron (less than 50 ppm) were determined by the ICP analysis.


Assuntos
Compostos Férricos/química , Metalurgia/métodos , Reciclagem , Sulfatos/química , Zinco/análise , Poeira/análise , Eletricidade , Ferro/química , Tamanho da Partícula , Ácidos Sulfúricos , Temperatura , Óxido de Zinco
18.
Waste Manag Res ; 38(9): 1037-1046, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32635825

RESUMO

The integration of the informal recycling sector into formal waste management systems is imperative to the implementation of the circular economy in the Global South. In Argentina, after the 2001 crisis, some large cities such as Buenos Aires greatly improved their informal recycling sector integration. In medium-size cities from the rest of the province, this was not the case. However, the formation of a national coalition between different sectors of what is now called the 'popular economy' forced the enactment, in the context of a new crisis, of a Social Emergency Law, which includes a Complementary Social Salary equivalent to half the minimum wage, among its main features. In this paper, we recap these recent changes and we use the InteRa framework in a case study to measure how, along with academic and civil society support actions, they influenced the informal recycling sector integration in an intermediate city of Buenos Aires province. Our results show that the inclusion of the informal recycling sector improved rapidly after the availability of the Complementary Social Salary. Nevertheless, we registered a hard-to-overcome stagnation in some indicators of the InteRa framework, related to the weak engagement of the local municipal government with the informal recycling sector. Importantly, the advent of the Complementary Social Salary was not reflected in any indicator because there is no specific action related to this aspect in the InteRa framework. This may give an insight into future methodology improvement.


Assuntos
Resíduos Sólidos/análise , Gerenciamento de Resíduos , Argentina , Cidades , Setor Informal , Reciclagem
19.
Waste Manag Res ; 38(9): 923-941, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32635832

RESUMO

Waste from the construction sector poses huge challenges for sustainable waste management. This is not only due to the vast amount of waste produced in construction and demolition activities, but also due to pollutants potentially contained in these products. Subject to these conditions, waste management must ensure recovery of as many resources as possible, while making sure to keep material loops clean. This demanding task requires more knowledge about the existing building stock and an adaptation of current demolition processes. Innovative technologies, such as Building Information Modelling, or modern frameworks, such as Geographic Information Systems, offer a high potential to synoptically provide stock material information for future demolition activities for individual objects to be deconstructed as well as for whole cities as a basis for managing the anthropogenic stock and potential urban mining. Suitable methods of data collection allow for acquiring the desired input for the generation of building stock models enriched with demolition-related information. With the latter, selective deconstruction strategies as well as appropriate waste stream routing agendas can be planned and executed, thereby securing safety at work during the demolition process itself and a waste stream routing according to the waste hierarchy. This review article gives an overview of currently deployed building material assessment tools (data capture and visualisation), both a prerequisite for improved information on materials and geometry (and thereby mass/volume). In addition, this article describes workflows employable for the purpose of urban mining in end-of-life buildings, of which one holistic approach will be described in depth.


Assuntos
Indústria da Construção , Gerenciamento de Resíduos , Cidades , Materiais de Construção , Documentação , Sistemas de Informação Geográfica , Resíduos Industriais , Reciclagem
20.
Water Res ; 183: 116050, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32629181

RESUMO

Recapture and recycling of irrigation water is often required to meet enormous water demands at horticultural nurseries. We tested four water types associated with a recycled irrigation system at a commercial container nursery in southern California for presence of oomycete plant pathogens from July 2015 to December 2017. These water types included: the main source of water originating from a reservoir, retention water from an on-site collection pond, irrigation water received by different growing areas within the nursery, and irrigation runoff captured in polyethylene sheet-lined runoff channels. The genera Phytophthora, Pythium, and Phytopythium together contributed more than 85% of the total oomycete population detected in the recycled irrigation system. The Phytophthora and Pythium genera were represented by member species from nine (1-4, 6-10) and eight (A, B, D-F, H-J) different sub-generic clades, respectively. Incoming water sourced from the reservoir was found to harbor known plant pathogens such as Phytophthora citricola-complex, P. capsici-cluster, P. tropicalis,P citrophthora-cluster, P. nemorosa-cluster, P. riparia, P. cryptogea-complex, P. parsiana-cluster, P. sp. nov. aff. kernoviae, Pythium dissotocum-complex, Py. oligandrum-cluster, Py. irregulare, and Phytopythium litorale. Runoff water showed the highest oomycete species richness and frequency of detection with both filtration and leaf baiting methods. In addition to plant pathogens, oomycete fish pathogens such as Aphanomyces laevis, Pythium chondricola-complex, Pythium flevoense-complex, and Saprolegnia diclina-complex were also detected in greater abundance in the recycled irrigation water. The oomycete species richness in the runoff water was correlated with several environmental parameters such as soil temperature. Greater oomycete richness in incoming water was associated with higher soil temperatures, whereas richness in runoff declines with increasing soil temperature, likely suggesting connections to weather-dependent nursery operations.


Assuntos
Phytophthora , Pythium , California , Reciclagem , Água
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