Potential of metal recovery from printed circuit boards in Brazil.

In this study, the generation of domestic waste electrical and electronic equipment (WEEE) and waste printed circuit board (WPCB) were estimated, from 2015 to 2030. Based on the number of EEE put on the Brazilian market, the possession rate in the Brazilian households and obsolescence amounts of five EEE types were estimated using time series. The results show that, between 2015 and 2030, the quantity of WEEE generated per year will increase from 131.87 kt to 195.22 kt. In this period, WPCB generation will stay around 10% of WEEE generation. Additionally, this study shows that the urban mining potential of the materials recoverable from WPCB can be an important revenue source, with environmental benefits deriving from energy savings and a reduction in CO2 emissions. The results of this study provide a quantitative basis that may help decision makers develop strategic policies for WEEE management, considering material circularity.

Relevant insights and concepts overlooked throughout the development of flow analysis. A tutorial.

The conceptual expansion, fast development, and general acceptance of flow analysis are consequence of its adherence to the principles of green and white analytical chemistry, and chemical derivatization plays an essential role in this context. Through the flow analysis development, however, some of its potentialities and limitations have been overlooked. This is more evident when the involved modifications in flow rates, timing and/or manifold architecture deteriorate the analytical signals. These aspects have not always been systematically investigated, and are addressed here in relation to flow analyzers with UV-Vis spectrophotometric detection. Novel strategies for solution handling, guidance for dealing with the aforementioned analytical signal deterioration, and an alternative possibility for exploiting differential aspiration are presented. The concept of blank reagent carrier stream is proposed.

A multicommuted system using bacterial cellulose for urease immobilization and copper (II)-MOF colorimetric sensor for urea spectrophotometric determination in milk.

This work describes determining urea in milk samples using a multicommuted approach with a urease enzyme immobilized in bacterial cellulose and solid MOF as a colorimetric reagent. The Cu(2+)-MOF was characterized by FTIR spectroscopy, XRD, and SEM. The urea quantification was based on the urea hydrolysis reaction catalyzed by urease and reacted with Cu(2+)-MOF forming [Cu(NH3)4]2+, monitored at 450 nm. Linear responses were obtained from 1.0 to 50.0 mg dL-1 urea (R = 0.9959, n = 11), detection and quantitation limits of 0.082 mg dL-1 and 0.272 mg dL-1 respectively, analytical frequency of 8 determinations per hour, 0.8 mL sample solution consumption. Potential interfering studies have shown the selectivity of the proposed method. Addition and recovery tests were performed obtaining variation from 90 to 103%. Applying the F-test and t-test, the results showed no significant difference at the 95% confidence level Comparing the proposed and the reference method.

Probabilistic material flow analysis of released nano titanium dioxide in Mexico.

Engineered Nanomaterials (ENMs) or products containing ENMs, known as nano-enabled products are commercialized globally by a large number of companies. Concern about the potential risks and negative impacts of releasing ENMs into the environment is under investigation. For this reason, methodologies to estimate the probable mass concentrations of ENMs released in different regions of the world have been developed. As a first attempt to estimate the probable mass flows of nanosized titanium dioxide (nano-TiO2) released in Mexico, we developed a Probabilistic Material Flow Analysis (PMFA) for 2015. The model describes probabilistic mass flows of released nano-TiO2 during the life cycle of sunscreens, coatings, ceramic, and other nano-enabled products, including the flows through the solid waste and wastewater management systems, as well as the transfer of nano-TiO2 to three environmental compartments (atmosphere, topsoil, and surface water). The PMFA incorporates the uncertainty related to the input data. We observed that the most significant nano-TiO2 flows occur to the surface water, landfill, and soil compartments, targeted as the main "hot-spots", where living organisms could be more exposed to this material. Further improvements in the model are needed due to some data gaps at some life cycle stages, for instance, solid waste management and reused wastewater manipulation for irrigation purposes. Finally, the model developed in this study can be adjusted to assess other ENM releases and can be beneficial for further investigation in fate modeling and environmental risk assessment.

Understanding nitrogen dynamics in the Brazilian beef industry: A comprehensive decadal analysis.

Brazil stands as a prominent beef producer and exporter, witnessing major transformations and expansions in its production chain over the past 20 years. These changes have prompted concerns regarding waste generation and environmental pressure. This study employs material flow analysis (MFA) to quantify nitrogen flows throughout the cattle slaughter process and subsequent beef consumption in Brazil, spanning from 2011 to 2021. The analysis encompasses co-production streams like leather, tallow, viscera, and blood. Nitrogen use efficiency (NUE) and the nitrogen cascade indicator (NCI) were used to evaluate efficiency and nitrogen accumulation in the production chain. Nitrogen inputs in the system increased by 8.47 %, while beef production rose by 7.29 %. In contrast, per capita beef consumption decreased by 1.29 kg, despite an overall consumption increase of 2.84 %, attributed to population growth in Brazil. Beef exports witnessed a notable surge of 86.03 %. Conversely, human excreta and food waste losses experienced increments of 10.88 % and 2.84 %, respectively. Examining NUE reveals the highest values during the slaughter phase (90 %), followed by processing, transportation, and storage stages (79-88 %). The consumption phase exhibited the lowest NUE values (29-34 %). Regarding the cumulative nitrogen effect, the NCI varied between 77 % and 82 % throughout the study period. This highlights opportunities for enhancing nitrogen use efficiency, particularly by addressing food waste at the consumer level. Notably, the study observes nitrogen accumulation across the Brazilian beef production chain, potentially contributing to the nitrogen cascade effect and heightening environmental pressure. Recognizing these dynamics provides avenues for targeted improvements, emphasizing the need to address nitrogen-related challenges and enhance sustainability in the beef production and consumption landscape.

Fluorimetric determination of aqueous formaldehyde employing heating and ultrasound-assisted approach through its derivatization with a ß-diketone-nickel(2+) complex immobilized in a PMMA flow cell.

Formaldehyde (FA) is a highly toxic substance present in many matrices, including freshwater as well as found in natural mechanisms such as rainfall and combustion of organic matter. Consumption of water contaminated with high levels of FA can cause severe short-term or long-term health problems. Due to these health risks, procedures are necessary to determine and quantify FA in aqua sources This paper reports on a study of fluorimetric determination of FA using a nickel(2 + )-diketonate coordination compound immobilized as a solid precursor. The compound was characterized by electronic absorption, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetry (TG), optical microscopy (OM), and scanner electron microscopy (SEM). The methodology was based on the reaction of the synthesized compound with an ammoniacal buffer generating a selective reagent for formaldehyde: fluoral-P. The product of the reaction generates 3,5-diacetyl-1,4-dihydrolutidine (DDL), which is responsible for the fluorescence of the system. Several parameters such as temperature, duration of heating time, and dilution effect with the best effects were studied to carry out FA determination. Under the optimum experimental conditions, a linear response ranging from 1.0 to 10.0 mg/L FA (R = 0.997 and n = 10), and a detection (3σ criterion) and quantification (10 σ criterion) limit estimated at 0.129 and 0.389 mg/L, respectively were achieved. The FA analysis was able to be conducted in 05 min with a relative standard deviation estimated at 1.10 %.

Advancing plastic pollution hotspotting at the subnational level: Brazil as a case study in the Global South.

Identifying sources is crucial for proposing effective actions to combat marine litter pollution. Here, we used an innovative approach to identify hotspots of mismanaged plastic waste (MPW) within Brazil and subsequent leakage to the ocean, based on population density, socio-economic conditions, municipal solid waste management and environmental parameters. We estimated plastic waste generation and MPW for each of the 5570 Brazilian municipalities, which totaled 3.44 million metric tons per year. Then, we estimated the probability of litter mobilization and transport (P) and the relative risk of leakage to the ocean (MPW × P). The Guanabara Bay and La Plata River comprised the main oceanic entry hotspots of litter produced in Brazil. The use of national databases allowed us to increase spatial and temporal granularity, offering a detailed baseline for the application of prevention and mitigation actions. However, overcoming data limitations is still a challenge in Brazil as in other Global South countries.

Empirical adsorption kinetics: comparing linear and nonlinear regression analysis emphasizing the need for high throughput analysis.

This paper evaluates linear and nonlinear regression analysis to describe the empirical adsorption kinetics using pseudo-first-order (PFO) and pseudo-second-order (PSO) models. These models have been used to characterize the performance of adsorbents for environmental remediation and environmental modeling. Data were simulated using the PFO and PSO models with 1, 2, and 5% noise levels and fitted by nonlinear and linearized PFO and PSO equations. Nonlinear regression analysis provided rate constants and adsorption capacities with better accuracy than linearization. Besides the correlation coefficient, Chi-square and residual plot analysis helped choose the proper model to describe the adsorbent efficiency and validate the results. Both models and the NLR fitting were employed to reevaluate data obtained in our research group, including the adsorption of Hg(II) on thiol-modified vermiculite, glyphosate on soils rich in aluminum and iron oxides, phosphate on Fe(III) polyhydroxy cations modified montmorillonite, and paraquat on soil and vermiculite. While fitting the simulated data indicates an unequivocal and correct kinetic model, fitting the experimental data is not straightforward, suggesting mixed models rule the adsorption and that a large number of data points, especially at the initial steps of adsorption, provided by high throughput analysis, help to improve the kinetic modeling.

Ocean-based sources of plastic pollution: An overview of the main marine activities in the Peruvian EEZ.

Marine-based activities are a critical source of plastic waste into the ocean. This is particularly important in countries with a competitive fishing industry, such as Peru. Thus, this study aimed to identify and quantify the major flows of plastic waste accumulating in the ocean from ocean-based sources within the Peruvian Economic Exclusive Zone. A material flow analysis was elaborated to analyze the stock of plastic and its release to the ocean by a set of Peruvian fleets, including the fishing industry, merchant vessels, cruises, and boating vessels. Results show that in 2018 between 2715 and 5584 metric tons of plastic waste entered the ocean. The fishing fleet was the most pollutant, representing approximately 97 % of the total. Moreover, fishing gear loss represented the highest single-activity contribution, although other sources, such as plastic packaging and antifouling emissions, have the potential to become vast sources of marine plastic pollution.

Brazilian soybeans as feed for livestock in Europe: an insight into the nitrogen flows.

Given the agricultural demand to supply animals with food, the scope of today's soybean production and international trade can influence the nitrogen cycle. Rather than using soybeans from within the region of animal production, animal producers import nutritional supplements from distant growers. This widely opens the biogeochemical cycle of nitrogen, which reduces local recycling and increases carriage of reactive nitrogen via the supply chain. Ultimately, this potentiates the effects of a "nitrogen cascade" process. This study estimates nitrogen flows for Brazilian soybean transported to feed European livestock and attempts to quantify the understanding of how this flow can impact the nitrogen cascade effect. The hypothesis is that the growing trade of Brazilian soybean products is sufficient to spike reactive nitrogen production that can potentially cause distant environmental impacts of the nitrogen cascade. In this respect, the estimation of the nitrogen flows was evaluated using material flow analysis, and the cascade effect was quantified by means of a nitrogen cascade indicator (NCI). Notably, NCI can calculate the released amount of nitrogen in the environment along the entire supply chain of livestock products. NCI-based evaluation of Brazilian soybean products consumed by European livestock indicated the accumulation of nitrogen levels. There was also an increase in nitrogen flows in the Brazilian phase (0.058 Gg in 2007 to 139.86 Gg in 2019 for soybean meal; 584.28 Gg in 2007 to 309.78 Gg in 2019 for soybeans) accompanying a stability in European livestock production. This highlights the necessity for adjustments in nitrogen circularity between all levels of food production and improved strategies of more localised feed autonomy for sustainable global development. Supplementary Information: The online version contains supplementary material available at 10.1007/s10113-023-02034-1.

Post-consumer plastic packaging waste flow analysis for Brazil: The challenges moving towards a circular economy.

Plastic packaging has been used increasingly worldwide in a broad range of application. Plastic packaging has a short lifetime, which generates a large amount of waste. However, robust information on plastic packaging waste flow is generally not available, especially for developing countries such as Brazil. We analyzed and quantified Brazilian post-consumer plastic packaging waste (PPW) flows using material flow analysis (MFA) for the year 2017. The system modeled covered from the manufacturing stage of plastic packaging up to its waste management stage. We used a range of data sources, whose quality we assessed using uncertainty characterization. The results showed that Brazil generated 12 Mt of PPW in 2017, and the management of 63% of that was not monitored. The majority of monitored PPW was disposed of into landfills, but 0.8 Mt of PPW was improperly disposed. Informal collection was 24% greater than formally managed selective collection. Only 4.5% of the PPW generated in Brazil was recycled. The results identified the major national challenges in relation to PPW management as being that information systems needed to be improved, informal waste collectors needed to be socially and productively included in the management systems, and recovery systems needed to be developed towards a circular economy.

Social metabolism and material flow analysis applied to waste management: A study case of Autonomous City of Buenos Aires, Argentina.

Waste Management in megacities is one of the most relevant issues around the world due to its environmental impacts and economic costs. In this work, we evaluate the application of the theoretical-methodological framework provided by Social Metabolism and Material Flow Analysis to analyze the Municipal Solid Waste Management in the Autonomous City of Buenos Aires (Argentina). The quantitative results evidence that 46% of the city's waste was disposed of in landfills outside its geographical limits, transferring environmental costs to the population on the outskirts of the city and other administrative jurisdictions. The city recycled the other 54% of the waste using different strategies like green centers for recyclable domestic waste (operated by 5500 registered Urban Recyclers/waste pickers recover), a Plant for treatment of pruning activities waste, a Plant for the treatment of construction and demolition waste, and a Mechanical-Biological Treatment Plant. Also in the city work, approximately 5000 informal waste pickers contributing to recycling waste. The approach shows the importance of the inclusion of waste pickers in the formal recycling system, and the failures of costly and inefficient large-scale technologies, as the Mechanical-Biological Treatment Plant. Also, the application of Social Metabolism and MFA allowed a characterization of the flows and processes that make up Municipal Solid Waste management in the area of study, despite the lack of systematized quantitative information. It facilitates a holistic visualization of waste management in the city for decision-makers.

The role of a socio-integrated recycling system in implementing a circular economy - The case of Belo Horizonte, Brazil.

Waste pickers (WPs) are considered a strong suggestion to become practical mediators of the circular economy (CE) in emerging economies. This new recommendation intends to strengthen WPs' role in household solid waste management while supporting the establishment of CE. Municipalities often do not recognize WPs as service providers and frequently discriminate against them. In such a challenging situation, could a socio-integrated recycling system with integrated WPs be a robust strategy to boost a CE? Belo Horizonte is a learning platform to answer this research question because this Brazilian city has a long-term commitment to social integration. The work applies the combination of participatory observation, multi-year material flow analysis (MFA), and structural agent analysis (SAA) to identify allocative resources, legitimation, and cultural values that are fundamental to operationalizing CE. The MFA results show a significant increase in waste generation, but not more than 4% of recyclable waste generated could be collected as input for WP cooperatives. The number of WPs registered in cooperatives, the market price of recyclables, and regulatory legislation for packaging products are classified as barriers for the successful extension of a socio-integrated recycling system identified in the SAA. This study suggests that knowing the target group (e.g., city hall and industries) brings opportunities for WPs to disclose niches (based on a small network of agents with expectations and visions) and can potentially create socio-technical regimes to implement a conscious and sustainable CE.

A Multi-Pump Magnetohydrodynamics Lab-On-A-Chip Device for Automated Flow Control and Analyte Delivery.

This article shows the development of a computer-controlled lab-on-a-chip device with three magnetohydrodynamic (MHD) pumps and a pneumatic valve. The chip was made of a stack of layers of polymethylmethacrylate (PMMA), cut using a laser engraver and thermally bonded. The MHD pumps were built using permanent magnets (neodymium) and platinum electrodes, all of them controlled by an Arduino board and a set of relays. The implemented pumps were able to drive solutions in the open channels with a flow rate that increased proportionally with the channel width and applied voltage. To address the characteristic low pressures generated by this kind of pump, all channels were interconnected. Because the electrodes were immersed in the electrolyte, causing electrolysis and pH variations, the composition and ionic strength of the electrolyte solution were controlled. Additionally, side structures for releasing bubbles were integrated. With this multi-pump and valve solution, the device was used to demonstrate the possibility of performing an injection sequence in a system that resembles a traditional flow injection analysis system. Ultimately, the results demonstrate the possibility of performing injection sequences using an array of MHD pumps that can perform fluid handling in the 0-5 µL s-1 range.

Identification and quantification of main anthropogenic stocks and flows of potassium in Brazil.

Potassium (K), along with nitrogen and phosphorus, is an essential resource to ensure agricultural productivity and, therefore, food security around the world. However, diminishing physical reserves of potash salts and high-price volatility of potassium chloride, the main source of K to agricultural soils, has raised concerns about a K scarcity scenario, mainly in countries that depend on fertilizer imports to sustain its production. In this context, Brazil is one of the main agricultural producers in the world, having a major role in the global K flows, since the country sustains its production by a high consumption of imported K fertilizers. In order to seek opportunities to contribute to a more sustainable management of K resources, tools such as the material flow analysis (MFA) can be used to highlight the main K stocks and flows in a country scale, and identify options for reuse and recycle. This study proposed a MFA of K for Brazil, considering the base-year 2013. A total of forty-four flows and seven stocks were identified and quantified considering nine main processes related to human activity. According to the results, for the year of study, the main inputs of K in Brazil were in the form of fertilizers (4.1 × 103 Gg of K per year), and the main outputs were in the form of grain exports (9.1 × 102 Gg of K per year). Agricultural soils were the main stock for K in the country, and from the total flow of 7.3 × 103 Gg of K per year applied to soils, 67% came out as agricultural products, 13% was lost through erosion and leaching, and 20% remained in the soils. The flow of K actually consumed by the Brazilian population was 3.5 × 102 Gg of K per year, just 8.4% of the total food produced in the country. About 1.9 × 103 Gg of K per year has been lost to the environment in sewage streams and solid landfill waste. Prospects for more sustainable K management in the country are identified and discussed.

Material Flow Analysis (MFA) and waste characterizations for formal and informal performance indicators in Tandil, Argentina: Decision-making implications.

In cities, the achievement of waste-related legal requirements and the main drivers of Integrated Sustainable Waste Management (ISWM) need adequate indicators and adaptable-to-case tools and strategies. In this work, we combine Material Flow Analysis (MFA) and waste characterizations to develop a mass balance table to design, calculate and analyse indicators related to the formal and informal waste sub-circuits of Tandil, a medium-sized city of the Buenos Aires province (Argentina). Results show that global recovery is very low (2.3% ± 0.16) and mainly driven by the Informal Recovery Sector (IRS). Also, the IRS strategy is more effective, recovering 40% ± 8.0 of its targeted materials from non-household sources. Regarding each material recovery performance, results show significant differences. For paper and board, recovery exceeds 20%. For HDPE, Tetra brik and Ferrous Metals are lower than 1%. In the case of PET and Glass, 9.6 and 9.0% of what is generated in households is recovered, respectively. However, the global recovery rate of each material is different: 2.9% ± 0.4 for PET and 5.5% ± 1.4 for Glass. Our research show that strategies in place are insufficient regarding legislation in force. Even a hypothetically 100% effectiveness in them will account only for 20.9% ± 2.1 of global recovery. Addressing organic waste, therefore, is imperative. Considering the current province law provision of final disposal diversion, accounting for the work of the IRS is key because they recover more waste than the official strategy. Regarding open dumps eradication, we estimate that up to 17% of generated waste is incorrectly final disposed through private skips illegally dumped. A tracking system for skips could avoid this situation.

Human urine fertiliser in the Brazilian semi-arid: Environmental assessment and water-energy-nutrient nexus.

This manuscript aimed to identify the energy demand, and environmental aspects and impacts of crop fertilisation with human urine when compared to using mineral fertilisers. The Material Flow Analysis and Life Cycle Assessment methods were adopted covering the options from "cradle to grave". The fertilisation with human urine included the collection, storage, transportation, application and field emissions, while the fertilisation with mineral fertilisers included primary production of fertilisers, transportation, application and field emissions. The reference flows were based on the fertilisation of 1 ha of maize with 225 kg of nitrogen, 29 kg of phosphorus and 48 kg of potassium oxide. We analysed the environmental aspects such as nitrogen and phosphorus mass balance, energy demand and water depletion, as well as environmental impacts such as global warming, human toxicity, photochemical ozone formation, acidification, eutrophication, freshwater ecotoxicity, water scarcity and resource depletion. The agricultural fertilisation with full volume of human urine closer to the source presented smaller energy demand and environmental impact indicator values when compared to solid mineral fertiliser, despite the uncertainties. The fertilisation with human urine was more advantageous with transportation distances up to 134 km (energy demand) and 84 km (environmental categories) by truck compared to 1841 km of mineral fertiliser. Ammonia volatilisation control was key to reduce acidification and eutrophication indicator values. When considering additional gains such as the reduction of water demand and wastewater generation from a waterless collection of human urine, the indicator values of environmental aspects and impacts of fertilisation with human urine were smaller than those with mineral fertiliser and reached a break-even point of 193 km (energy demand) and 185 km (environmental categories). The nutrient cycling through resource-based sanitation offers an opportunity to expand sanitation access with smaller environmental impacts and more efficient water-energy-nutrient nexus.

Fast-response flow-based method for evaluating 131I from biological and hospital waste samples exploiting liquid scintillation detection.

This paper presents a fast and automatic flow-based method to extract 131I from biological samples and hospital waste, previous to liquid scintillation detection. 131I is a radionuclide extensively used in Nuclear Medicine due to their beta and gamma disintegrations, whereby hospitals have to manage the associated waste generation. The automatic developed system is based on Lab-On-Valve (LOV) flow-technique exploiting Cl-resin (135 mg per extraction). This methodology allows performing sample extractions and measurements on the same day, since the extraction frequency takes 1.4-4 h-1, depending on the analysed sample volume, plus up to 2 h of measurement for each vial. 131I is retained as iodine ion and eluted with sodium sulphide 0.2 mol L-1. The maximum sample volume that can be preconcentrated is 20 mL, reaching an extraction efficiency of 85 ±â€¯5%. The minimum detectable activity (MDA) is 0.05 Bq, showing a precision of 7% RSD (n = 5). Both, biological samples (urine and saliva) and hospital waste samples can be satisfactorily analysed by the proposed system, obtaining recoveries between 90 and 110%. The developed method is then suitable to implement in hospitals, improving the surveillance of the 131I environmental release.

Flow analysis during the 60 years of Talanta.

A parallel within the development of flow analysis and the consolidation of Talanta as one of the main journals in analytical chemistry is drawn. Influence of scientific divulgation, meeting organizations, thematic issues devoted to scientific events and Talanta awards in the recent development of flow analysis is emphasized. For didactic purposes, the discussion is focused on three 20-year periods. A scientometric overview demonstrated the consolidation of Talanta as the main journal for divulgation of recent innovations in flow analysis.

Flow thermal infrared enthalpimetry: Rapid and inexpensive determination of the alcohol content of distilled beverages.

In this work, a simple and inexpensive flow thermal infrared enthalpimetry (TIE-F) method was developed through a combination of flow injection analysis and thermal infrared enthalpimetry (TIE) to determine the alcohol content of distilled beverages (cachaça, cognac, and vodka). The principle used in this method consisted of monitoring the enthalpy of dissolution of ethanol through a low-cost infrared sensor coupled to a flow system. The results showed an agreement between the proposed method and the conventional method, ranging from 96.5% to 99.0%. The obtained limit of quantification (LOQ, 10σ) of 25.10% (v/v) was enough for distilled beverages, which should present a minimum alcoholic content of 36% according to Brazilian legislation. In addition, the TIE-F instrumentation presented costs that were 100 times lower than the instrumentation that was used in the batch TIE, and the time of analysis was significantly reduced. The amount of residue generated was also reduced, thereby providing significant energy savings and easy adaptation to processes on industrial scales.