International Cooperation for Metal Recycling From Waste Electrical and Electronic Equipment

This article addresses a market‐based management concept for waste electrical and electronic equipment (WEEE) known as the “best‐of‐two‐worlds” approach. The concept is based on the idea that recyclers in developing countries and emerging economies can cooperate with technologically advanced refineries in industrialized countries to facilitate efficient recovery of valuable metals, such as gold and palladium, from e‐waste. The article provides an overview of technical and environmental concerns underlying the concept and sheds light on the political framework, the waste‐related trade issues, and the resource economics that need to be considered for further decision making. Building on this synthesis, I conduct a qualitative assessment of sustainability impacts of the proposed concept by analyzing two scenarios and their associated risks. The analysis suggests that, under certain preconditions, the best‐of‐two‐worlds concept could yield significant improvements in terms of management of hazardous substances, resource efficiency, greenhouse gas emissions, income generation, and investments into social and environmental standards. Generally, two potential implementation scenarios were identified: Whereas under Scenario 1 only WEEE generated within developing countries and emerging economies is managed through the best‐of‐two‐worlds approach, Scenario 2 additionally incorporates WEEE imported from industrialized countries. Although both scenarios can yield a variety of benefits, Scenario 2 might cause a net flow of hazardous substances from industrialized countries into developing countries and emerging economies, thus leading to less beneficial sustainability impacts.     

From Cradle to Grave: Extended Producer Responsibility for Household Hazardous Wastes in British Columbia

Household hazardous wastes (HHWs), the discarded pesticides, solvents, paints, lubricating oil, and similar products common to residences throughout the industrial world, create problems for governments charged with managing solid waste. When disposed of improperly in landfills or incinerators or if dumped illegally, HHW may contribute to soil and water contamination. A most common management tool for HHW is a special collection effort that segregates HHW from normal trash and disposes of it in an approved manner, all at a higher cost to the governmental jurisdiction. The Canadian province of British Columbia (BC) has undertaken a different approach, based on the use of extended producer responsibility (EPR). BC's efforts began in 1992 with adoption of a regulation on used lubricating oil (lube oil). More than 40 million liters (L) of used lube oil have been collected annually through the EPR system established under this regulation. A regulation establishing producer responsibility for postconsumer paints followed in 1994. BC enacted an additional regulation establishing EPR in 1997 for solvents/flammable liquids, domestic pesticides, gasoline, and pharmaceuticals. As a result of the application of EPR to HHW, local government costs for managing HHW and the amount of HHW identified in municipal waste have declined. Although the regulations appear to have mixed success in prompting consumers to avoid products that result in HHW, there are indications that they may be more effective than conventional management efforts. Based on BC's experience with EPR, key factors for successful implementation include maintaining flexibility in program design, creating viable funding alternatives, aggressive enforcement to provide a level playing field, and adopting policies that maximize diversion of HHW from landfills, while minimizing waste generation, setting targets for reuse and recycling, promoting consumer awareness and convenience, involving local government jurisdictions, and monitoring outcomes.     

India's E‐Waste Rules and Their Impact on E‐Waste Management Practices: A Case Study

India, like many other developed and developing countries, has adopted an extended producer responsibility (EPR) approach for electronic waste (e‐waste) management under its E‐waste (Management and Handling) Rules, 2011. Under these rules, producers have been made responsible for setting up collection centers of e‐waste and financing and organizing a system for environmentally sound management of e‐waste. In this article, we use the implementation of these rules in Ahmedabad in western India as a case study to conduct a critical analysis of the implementation of India's Rules. Interviews of main stakeholder groups, including a sample of regulated commercial establishments, regulatory agencies enforcing the Rules, informal actors involved in waste collection and handling, as well as publicly available information on the implementation constitute data for our case study. Our results indicate that while there has been an increase in the formal waste processing capacity after the implementation of the Rules, only 5% to 15% of the total waste generated is likely channeled through formal processing facilities. While the EPR regulation forced the producers to take action on a few relatively inexpensive aspects of the Rules, the collection and recycling system has not been made convenient for the consumers to deposit e‐waste in formal collection and recycling centers. Based on our findings, we argue that Indian EPR regulation should go beyond simple take‐back mandates and consider implementing other policy instruments such as a deposit‐refund system. An important implication for developing countries is the need for careful attention to instrument choice and design within EPR regulations.     

A Statistical Analysis of Prices of Electrical and Electronic Equipment after the Introduction of the WEEE Directive

In January 2003, the European Union (EU) issued a directive on e‐waste (waste from electrical and electronic equipment; WEEE) to deal with increasing quantities and the included hazardous components. The WEEE Directive is based on the principle of extended producer responsibility, which shifts the responsibility for end of life of products away from municipalities toward producers. This led some researchers to state that, in theory, the costs of waste treatment are passed on to consumers in terms of higher prices. This work addresses two fundamental questions: (1) Did the introduction of the WEEE Directive increase consumer prices of electrical and electronic equipment (EEE)? and (2) how much is this price increase? We carry out, for the first time in the literature, a quantitative research on price variation of the vast majority of EEE sold in the EU after the introduction of producers’ financial responsibility. The panel data include 972 price level indices, namely, six categories of EEE for 27 member states for six years. The main result is that the average variation of the prices for each category of EEE investigated actually increased and the variation was between 0.71% and 3.88%, depending on the specific category of EEE. The average increase of 2.19% is in line with the previous studies that estimated the impact of the WEEE Directive up to a 3% increase of the product price. The t‐test performed on the data shows a good statistical significance, which strengthens the relevance of the results. Finally, future directions for research are included.     

Assessment of sustainable development in the EU 27 using aggregated SD index

In the European Union the sustainable development is a fundamental and overarchingobjective enshrined in the Treaty and measuring progress towards sustainable development is an integral part of the EU Sustainable Development Strategy. Eurostat produce a monitoring report every two years based on the EU set of sustainable development indicators (SDIs). The main objective of this paper is to create an aggregated index of the sustainable development from EU set of SDIs for each 27 EU country based on the PCA. The headline indicator economic growth was not involved because its increase is not expressly followed by positive change in other SDIs from social, economic and environmental fields. The aggregated SD index enables to get an overall picture about the position of each of the 27 EU countries and its development in terms of the sustainability over time as assumed in the EU Sustainable Development Strategy. Sweden, Denmark, Netherland, and Great Britain have repeatedly reached the highest value of aggregated SD index. The highest positive change in the aggregated SD index has occurred in countries with the lowest value of aggregated SD index. Moreover, we put this new aggregated index in relation with economic growth and found that there is a negative correlation between aggregated SD index and the economic growth for most of the 27 EU countries.     

Transdisciplinary Development of a Life Cycle–Based Approach to Measure and Communicate Waste Prevention Effects in Local Authorities

Although waste prevention was promoted as the first priority for all EU member states in 2008, the actual implementation of activities has thus far been hesitant. Empirical evidence indicates that the reasons for this neglect include the limited measurability of waste prevention effects and the consequential lack of awareness, motivation, and incentive systems. Our research aims to quantify waste prevention and its environmental impacts and, ultimately, to motivate the efficient implementation of waste prevention concepts by a target‐group‐specific communication of the results. Embedded in a transdisciplinary research setting in close cooperation with practitioners, we develop a life cycle–based approach to calculate the effects of waste prevention in local authorities. This approach features an activity‐based analysis that facilitates the assessment of both reduction of waste generated and the related environmental effects. The methodology of life cycle assessment, used to calculate environmental impacts, is adapted to the specific requirements and constitutes an essential step in our measurement approach. Finally, we demonstrate the application of this approach. Five activities deriving from real‐world case studies are assessed. These case studies simulate the implementation of waste prevention in a mid‐sized German city. We are able to reveal potential waste reduction of 74% and potential reduction of other environmental impacts ranging from 28% to 62% of the targeted material streams.     

Food waste within food supply chains: quantification and potential for change to 2050

Food waste in the global food supply chain is reviewed in relation to the prospects for feeding a population of nine billion by 2050. Different definitions of food waste with respect to the complexities of food supply chains (FSCs)are discussed. An international literature review found a dearth of data on food waste and estimates varied widely; those for post-harvest losses of grain in developing countries might be overestimated. As much of the post-harvest loss data for developing countries was collected over 30 years ago, current global losses cannot be quantified. A significant gap exists in the understanding of the food waste implications of the rapid development of ‘BRIC’ economies. The limited data suggest that losses are much higher at the immediate post-harvest stages in developing countries and higher for perishable foods across industrialized and developing economies alike. For affluent economies, post-consumer food waste accounts for the greatest overall losses. To supplement the fragmentary picture and to gain a forward view, interviews were conducted with international FSC experts. The analyses highlighted the scale of the problem, the scope for improved system efficiencies and the challenges of affecting behavioural change to reduce post-consumer waste in affluent populations.     

Maintenance and Expansion: Modeling Material Stocks and Flows for Residential Buildings and Transportation Networks in the EU25

Material stocks are an important part of the social metabolism. Owing to long service lifetimes of stocks, they not only shape resource flows during construction, but also during use, maintenance, and at the end of their useful lifetime. This makes them an important topic for sustainable development. In this work, a model of stocks and flows for nonmetallic minerals in residential buildings, roads, and railways in the EU25, from 2004 to 2009 is presented. The changing material composition of the stock is modeled using a typology of 72 residential buildings, four road and two railway types, throughout the EU25. This allows for estimating the amounts of materials in in‐use stocks of residential buildings and transportation networks, as well as input and output flows. We compare the magnitude of material demands for expansion versus those for maintenance of existing stock. Then, recycling potentials are quantitatively explored by comparing the magnitude of estimated input, waste, and recycling flows from 2004 to 2009 and in a business‐as‐usual scenario for 2020. Thereby, we assess the potential impacts of the European Waste Framework Directive, which strives for a significant increase in recycling. We find that in the EU25, consisting of highly industrialized countries, a large share of material inputs are directed at maintaining existing stocks. Proper management of existing transportation networks and residential buildings is therefore crucial for the future size of flows of nonmetallic minerals.     

Life cycle assessment of a pyrolysis/gasification plant for hazardous paint waste

Goal, Scope and Background Life Cycle Assessment (LCA) remains an important tool in Dutch waste management policies. In 2002 the new National Waste Management Plan 2002–2012 (NWMP) became effective. It was supported by some 150 LCA studies for more than 20 different waste streams. The LCA results provided a benchmark level for new waste management technologies. Although not new, operational techniques using combined pyrolysis/gasification are still fairly rare in Europe. The goal of this study is to determine the environmental performance of the only full scale pyrolysis/gasification plant in the Netherlands and to compare it with more conventional techniques such as incineration. The results of the study support the process of obtaining environmental permits. Methods In this study we used an impact assessment method based on the guidelines described by the Centre of Environmental Science (CML) of Leiden University. The functional unit is defined as treatment of 1 ton of collected hazardous waste (paint packaging waste). Similar to the NWMP, not only normalized scores are presented but also 7 aggegated scores. All interventions from the foreground process (land use, emissions, final waste) are derived directly from the site with the exception of emissions to soil which were calculated. Interventions are accounted to each of the different waste streams by physical relations. Data from background processes are taken from the IVAM LCA database 4.0 mostly originating from the Swiss ETH96 database and adapted to the Dutch situation. Allocation was avoided by using system enlargement. The study has been peer reviewed by an external expert. Results and Discussion It was possible to determine an environmental performance for the pyrolysis/ gasification of paint packaging waste. The Life Cycle Inventory was mainly hampered by the uncertainty occurred with estimated air emissions. Here several assumptions had to be made because several waste inputs and two waste treatment installations profit from one flue gas cleaning treatment thus making it difficult to allocate the emission values from the flue gasses. Compared to incineration in a rotary kiln, pyrolysis/gasification of hazardous waste showed better scores for most of the considered impact categories. Only for the impact categories biodiversity and life support the incineration option proved favorable due to a lower land use. Several impact categories had significant influence on the conclusions: acidification, global warming potential, human toxicity and terrestrial ecotoxicity. The first three are related to a better energy efficiency for pyrolysis/gasification leading to less fossil energy consumption. Terrestrial ecotoxicity in this case is related to specific emissions of mercury and chromium (III). A sensitivity analysis has been performed as well. It was found that the environmental performance of the gasification technique is sensitive to the energy efficiency that can be reached as well as the choice for the avoided fossil energy source. In this study a conservative choice for diesel oil was made whereas a choice for heavy or light fuel oil would further improve the environmental profile. Conclusions Gasification of hazardous waste has a better environmental performance compared to the traditional incineration in rotary kilns mainly due to the high energy efficiency. As was determined by sensitivity analysis the differences in environmental performance are significant. Improvement options for a better performance are a decrease of process emissions (especially mercury) and a further improvement of the energy balance by decreasing the electricity consumption for shredders and oxygen consumption or making more use of green electricity. Recommendations and Perspectives Although the life cycle inventory was sufficiently complete, still some assumptions had to be made in order to establish sound mass balances on the level of individual components and substances. The data on input of waste and output of emissions and final waste were not compatible. It was recommended that companies put more emphasis on data storage accounted to particular waste streams. This is even more relevant since more companies in the future are expected to include life cycle impacts in their environmental performance.     

Anaerobic solubilisation of nitrogen from municipal solid waste (MSW)

This paper reviews anaerobic solubilisation of nitrogen municipal solid waste (MSW) and the effect of current waste management practises on nitrogen release. The production and use of synthetically fixed nitrogen fertiliser in food production has more than doubled the flow of excessive nitrogenous material into the community and hence into the waste disposal system. This imbalance in the global nitrogen cycle has led to uncontrolled nitrogen emissions into the atmosphere and water systems. The nitrogen content of MSW is up to4.0% of total solids (TS) and the proteins in MSW have a lower rate of degradation than cellulose. The proteins are hydrolysed through multiple stages into amino acids that are further fermented into volatile fatty acids, carbon dioxides, hydrogen gas, ammonium and reduced sulphur. Anaerobic digestion of MSW putrescibles could solubilise around 50% of the nitrogen. Thus, the anaerobic digestion of putrescibles may become an important method of increasing the rate of nitrogen recycling back to the ecosystem. A large proportion of the nitrogen in MSW continues to end up inland fills; for example, in the EU countries around 2 million tonnes of nitrogen is disposed of annually this way. Nitrogen concentration in the leachates of existing landfills are likely to remain at a high level for decades to come. Under present waste management practices with a relatively low level of efficiency in the source segregation or mechanical sorting of putrescibles from grey waste and with a low level of control over landfill operating procedures, nitrogen solubilisation from landfilled waste will take at least a century. This revised version was published online in June 2006 with corrections to the Cover Date.     

Replacement value of hatchery waste meal for fish meal in layer diets

An experiment was conducted in which hatchery waste meal (HWM) replaced fish meal (protein for protein) in layer diets at 0%, 33%, 66% and 100% levels. Both feed and protein intake were superior on HWM diets. The highest hen-day production of 73.97% was obtained on diet 2 in which 33% of fish meal was replaced with HWM. Egg weight and egg length were also superior on HWM diets. All birds fed on HWM diets had thicker egg shells (0.33 mm) than did those fed on the control diet, fish meal diet (0.32 mm). Results obtained for yolk weight were statistically different (P < 0.05). Highest values for yolk weight (16.91 g) and albumen weight (40.93 g) were recorded for birds fed with diet 4 in which 100% fish meal was replaced with HWM. HWM can replace fish meal completely in layer diets without adverse effect on egg quality characteristics.     

Ochratoxin A Analysen im Blut von Arbeitnehmern in der Abfallwirtschaft

Tasks such as manual sorting of domestic wastes for recyclable goods and the deposition of various materials may result in inhalation of mycotoxin-containing aerosols. Ochratoxin A (OTA) was analyzed in blood samples from workers employed at waste handling facilities in Southern Germany to assess the potential impact of this mycotoxin, and explore its use as a biomarker of exposure to bioaerosols. Results from this analysis are reported: OTA serum levels (median values) in subgroups of workers involved in waste deposition (n=76 ‘Deponierer’) or in waste sorting (n=60 ‘Wertstoffsortierer’) were 0.36 and 0.53 ng/ml, respectively. Both groups are natives of countries within the European Community (EU). In waste sorters who were born in other European (non-EU) countries (n=72) or elsewhere (n=12 from Asia, Africa), the OTA serum levels were 0.50 and 0.37 ng/ml, respectively. In controls (n=84 office clerks at the facilities; EU citizens) the median OTA value was 0.39 ng/ml. Comparing the different groups, and previously published data on median OTA levels in the general population (0.21 ng/ml) which result from dietary (background) exposure to OTA in Germany, our data point to an additional uptake of this mycotoxin by inhalation in workers with exposure to bioaerosols. The results support the view that apart from the pathogenic and allergological relevance of microbial emissions from garbage, secondary fungal metabolites, and thus toxicological aspects, deserve further attention.

Presented at the 25^th Mykotoxin Workshop in Giessen, Germany, May 19–21, 2003     

Biological disposal of hazardous waste

Hazardous wastes pose major disposal problems for all industrialized nations and a need exists to develop effective and permanent solutions. Biological technologies can assist in this regard. Biosystems can serve to recover, separate and destroy the toxic nature of hazardous waste at the source of generation, at abandoned landfills, in surface and ground waters and at the site of spills. When applying biotechnologies there are many physical, chemical and biological factors that must be considered when engineering an environment, with the biological component improved through the use of applied microbiology and genetic engineering. Biotreatment process systems include conventional aerobic and anaerobic technologies, land treatments similar to farming operations and composting, and novel techniques to treat surface and ground waters. Emerging techniques include free and immobilized cells and enzymes in batch and continuous systems, high-rate fermentations, and coupling of biotechnologies to physical/chemical methods. To develop an effective biological disposal option, research and development is required in a wide range of areas associated with microbiology and genetic engineering, and system design and testing.     

Business‐to‐Business Information Technology User Practices at End of Life in the United Kingdom,Germany, and France

Business‐to‐business (B2B) electronics account for a significant volume of the electrical and electronic equipment (EEE) put on the market. Very little B2B waste electrical and electronic equipment (WEEE) is reported as collected in the European Union (EU) in compliance with the WEEE Directive, which uses the policy principle of extended producer responsibility (EPR) to ensure that WEEE is managed correctly. This presents a barrier to parties looking for access to the waste. Company practice dictates the channels into which B2B WEEE flows following primary use. This article presents a study that engaged with company actors directly to get a better understanding of business information technology (IT) EEE asset management. Data were collected to determine the barriers current practice could present to the collection of B2B IT EEE at end of life and the implications of these for the development of policies and strategies for EPR. A questionnaire was developed and data were gathered from organizations in three EU countries—the United Kingdom, Germany, and France—stratified by size. Some notable findings were that there are several routes by which end‐of‐life B2B WEEE can flow. The recycling and refurbishment of B2B IT units at end of use was shown to be commonplace, but it is likely that these units enter streams where they are not reported. The actors disposing of their units did not have information on the management or disposition of these streams. It is concluded that to achieve the goals of EPR for B2B IT WEEE, the networks and the operational practices of these streams need to be better understood when developing strategies and policies.     

Application of a Life Cycle Model for European Union Policy‐Driven Waste Management Decision Making in Emerging Economies

Solid waste life cycle modeling has predominantly focused on developed countries, but there are significant opportunities to assist developing and transition economies to minimize the environmental impact of solid waste management (SWM). Serbia is representative of a transition country and most (92%) of its waste is landfilled. As a Candidate European Union (EU) country, Serbia is expected to implement SWM strategies that meet EU directives. The Solid Waste Life‐Cycle Optimization Framework (SWOLF) was used to evaluate scenarios that meet EU goals by 2030. Scenarios included combinations of landfills, anaerobic digestion, composting, material recovery facilities (MRFs), waste‐to‐energy (WTE) combustion, and the use of refuse‐derived fuel in cement kilns. Each scenario was evaluated with and without separate collection of recyclables. Modeled impacts included cost, climate change, cumulative fossil energy demand, acidification, eutrophication, photochemical oxidation, total eco‐toxicity, and total human toxicity. Trade‐offs among the scenarios were evaluated because no scenario performed best in every category. In general, SWM strategies that incorporated processes that recover energy and recyclable materials performed well across categories, whereas scenarios that did not include energy recovery performed poorly. Emissions offsets attributable to energy recovery and reduced energy requirements associated with remanufacturing of recovered recyclables had the strongest influence on the results. The scenarios rankings were robust under parametric sensitivity analysis, except when the marginal electricity fuel source changed from coal to natural gas. Model results showed that the use of existing infrastructure, energy recovery, and efficient recovery of recyclables from mixed waste can reduce environmental emissions at relatively low cost.     

基于物质流分析的废纸回收利用体系生态成本研究

废弃物回收利用在一定程度上对缓解资源和环境危机起到积极的作用,已经成为可持续发展的重要举措,但生产过程中消耗的资源、能源,排放的污染物同样也会对自然环境产生负面影响。为解决此问题,以废纸回收利用体系为例,基于物质流分析方法构建了生态成本核算模型,为废弃物回收利用体系优化提供基础。在对生态成本相关研究归纳总结的基础上,定义了生态成本的概念,界定了生态成本的研究内容,并分析基于物质流核算生态成本的可行性。生态成本是对生态负荷的价值化,主要分为资源耗减成本、污染产生和环境保护成本以及生态环境损害成本3部分。污染产生和环境保护成本可以通过将总成本按比例分配给正、负产品的方式求得,资源耗减成本和环境损害成本借助LIME方法核算,总生态成本是回收利用体系内部各项生态成本的总和。生态成本核算是评价生态负荷的重要手段,在废纸回收利用体系物质流动图的基础上,分析各生产流程生态成本的构成情况。提出的生态成本核算模型不仅适用于废纸回收利用体系,其他废弃物也同样适用。通过生态成本的核算,寻找到对生态环境影响较大的工序、流程,为废弃物回收利用体系经济与环境的双赢提供理论与实践指导。     

后疫情时代全球可持续发展目标加速行动的推动

“SDGs加速行动”是国际组织、政府部门、私营机构和其他利益攸关方为加快落实2030年可持续发展议程采取的全球行动。2019年联合国可持续发展目标峰会后,政府、国际组织、私营部门等提出了214项SDGs加速行动。2019年爆发的新型冠状病毒肺炎（Corona Virus Disease 2019,COVID-19）对实现可持续发展目标带来了系列影响,后疫情时代如何推动全球SDGs加速行动的实施成为重要的问题。对可持续发展评估报告（2019）和可持续发展目标加速行动等政策文件进行信息提取,建立加速行动匹配性指数模型和各国应对新冠疫情的恢复力指数模型,根据匹配性-恢复力分类体系将各国按照17项可持续发展目标分为9类,为推动后疫情时代全球可持续发展目标加速行动提供支撑。研究发现：（1）现有可持续发展目标加速行动的实施与区域需求不匹配,且这种不匹配的情况在COVID-19爆发前已经出现;（2）加速行动的实施受限于现有可持续发展水平和国家经济基础,区域关注的可持续发展目标与其自然地理位置和社会发展水平有着密切的关系,多边组织机构和其他利益攸关方需要在发展中国家大力推动可持续发展加速行动;（3）下一步实施加速行动需要加强国际间的合作,根据分类框架和可持续发展目标的关联关系,分重点推进加速行动的实施,完善可持续发展指标监测体系,分类设立后疫情时代不同时期的阶段目标,分阶段循序渐进,定期反馈追踪,以在2030年促进17项可持续目标的实现。     

Enzyme-based strategy for toxic waste treatment and waste minimization

The increasing amounts of pesticides used throughout the world, as well as the increasingly stringent governmental regulations concerning waste disposal, mandates improved techniques of waste disposal and minimization. In this article, parathion hydrolase, an enzyme with proven effectiveness at hydrolyzing organophosphates, was used to treat a cattle dipping liquid containing the pesticide, coumaphos, which is used to kill a disease-causing tick. Waste is generated from this process when a toxic dechlorination product of coumaphos, potasan, accumulates to concentrations hazardous to the cattle. This pesticide system was used as a model to demonstrate how enzyme technology can be applied to waste treatment and minimization. Kinetic experiments showed that the hydrolysis of the two organophosphate substrates can be modeled as first-order reactions with identical rate constants. It was further shown that the enzyme is capable of hydrolyzing only dissolved substrates. Because of the eightfold greater solubility of potasan than coumaphos (16.9 vs. 2.2 mumol/L), it was possible to utilize the enzyme to hydrolyze potasan selectively. Thus, by limiting the amount of enzyme, it is possible to remove potasan selectively to extend the lifetime of the cattle dipping liquid, thereby reducing the amount of waste generated. Based upon experimental results, a mathematical model describing the system was developed and verified. The mathematical model was then used to simulate the ability of the enzyme to hydrolyze the total amount of organophosphates, and to degrade selectively all of the toxic potasan without a significant loss of coumaphos.     

Modeling Biowaste Flows for Life‐Cycle Assessment: Calculation of the Potential and Collected Weight of Kitchen and Garden Waste

This article presents an integrative approach to calculating the weight of potential biowaste and collected biowaste materials, as the basis for a life‐cycle assessment (LCA) of biowaste management. Biowaste contains kitchen and garden (yard) waste of households. This approach could be used for waste management planning and for the implementation of biowaste schemes. Case studies and examples in the literature are analyzed to model the mass of the flow of biowaste. This article defines relevant operands, presents the main assumptions, and describes the calculation principles. Spatial aspects and the uncertainties related to the inclusion of this aspect are explicitly considered in the calculation of the weight of the potential biowaste. We also present the calculation principles for obtaining the weight of (1) biowaste used in home composting, (2) the organic portion of residual waste, (3) biowaste separately collected by a bring system, and (4) biowaste separately collected by curbside collection (known in some areas as kerbside collection). By choosing the biowaste potential in kilograms per capita year (kg/cap yr) as the functional unit, previously ignored options within the biowaste system could be assessed. For example, widening the system boundaries allows LCA studies to assess the contribution of private and public transport of waste to ecological impact categories. It allows examining the effects of supporting home composting through financial incentives and the introduction of a separate collection system. This study focuses on the comparison of different collection types and on the characteristics of the area under investigation. It also incorporates the behavior of the inhabitants of households and includes a sensitivity analysis of relevant operands. This approach is being included in an LCA assessing biowaste management options.     

Hybrid watermilfoil (Myriophyllum spicatum × Myriophyllum sibiricum) exhibits traits associated with greater invasiveness than its introduced and native parental taxa

Hybridization has been associated with increased invasiveness in plants. In North America, the hybrid aquatic plant Myriophyllum spicatum?×?Myriophyllum sibiricum (hybrid watermilfoil, hereafter HWM) is a cross between non-native invasive Eurasian watermilfoil (M. spicatum, EWM) and native northern watermilfoil (M. sibiricum, NWM). Lab-based trials have demonstrated higher growth rates in HWM compared to EWM and NWM, but these patterns have not been systematically examined in the field. In this study, we compared the invasiveness of HWM to its parental taxa, EWM and NWM, by examining the amount and timing of: (1) flowering, (2) surface cover, and (3) biomass (using stem counts as a proxy). We conducted repeat surveys of Myriophyllum beds at eight lakes (2–3 lakes/taxon) in the Minneapolis–St. Paul Metropolitan area (Minnesota, USA) between June 2017 and November 2018. HWM produced more flower spikes earlier and overall, and maintained consistently more flower spikes throughout the growing season than EWM and NWM. In addition, surface cover reached greater annual peaks and was higher for longer throughout the growing season for HWM than for both parental taxa. We did not observe a significant difference in stem counts among the three taxa, but HWM did reach a higher maximum number of stems than either parental taxon. This study provides field-based evidence of increased invasiveness associated with hybridization between EWM and NWM; specifically, greater reproductive potential via flowering and greater surface cover may increase HWM spread, have greater impacts on native species, and pose more of a nuisance to lake users.