Urban Waste Streams Research Articles

Accounting for the Ecological Footprint of Materials in Consumer Goods at the Urban Scale

Ecological footprint analysis (EFA) can be used by cities to account for their on-going demands on global renewable resources. To date, EFA has not been fully implemented as an urban policy and planning tool in part due to limitations of local data availability. In this paper we focus on the material consumption component of the urban ecological footprint and identify the ‘component, solid waste life cycle assessment approach’ as one that overcomes data limitations by using data many cities regularly collect: municipal, solid waste composition data which serves as a proxy for material consumption. The approach requires energy use and/or carbon dioxide emissions data from process LCA studies as well as agricultural and forest land data for calculation of a material’s ecological footprint conversion value. We reviewed the process LCA literature for twelve materials commonly consumed in cities and determined ecological footprint conversion values for each. We found a limited number of original LCA studies but were able to generate a range of values for each material. Our set of values highlights the importance for cities to identify both the quantities consumed and per unit production impacts of a material. Some materials like textiles and aluminum have high ecological footprints but make up relatively smaller proportions of urban waste streams than products like paper and diapers. Local government use of the solid waste LCA approach helps to clearly identify the ecological loads associated with the waste they manage on behalf of their residents. This direct connection can be used to communicate to citizens about stewardship, recycling and ecologically responsible consumption choices that contribute to urban sustainability.

Point sources of emerging contaminants along the Colorado River Basin: Source water for the arid Southwestern United States

Emerging contaminants (ECs) (e.g., pharmaceuticals, illicit drugs, personal care products) have been detected in waters across the United States. The objective of this study was to evaluate point sources of ECs along the Colorado River, from the headwaters in Colorado to the Gulf of California. At selected locations in the Colorado River Basin (sites in Colorado, Utah, Nevada, Arizona, and California), waste stream tributaries and receiving surface waters were sampled using either grab sampling or polar organic chemical integrative samplers (POCIS). The grab samples were extracted using solid-phase cartridge extraction (SPE), and the POCIS sorbents were transferred into empty SPEs and eluted with methanol. All extracts were prepared for, and analyzed by, liquid chromatography–electrospray-ion trap mass spectrometry (LC–ESI-ITMS). Log DOW values were calculated for all ECs in the study and compared to the empirical data collected. POCIS extracts were screened for the presence of estrogenic chemicals using the yeast estrogen screen (YES) assay. Extracts from the 2008 POCIS deployment in the Las Vegas Wash showed the second highest estrogenicity response. In the grab samples, azithromycin (an antibiotic) was detected in all but one urban waste stream, with concentrations ranging from 30ng/L to 2800ng/L. Concentration levels of azithromycin, methamphetamine and pseudoephedrine showed temporal variation from the Tucson WWTP. Those ECs that were detected in the main surface water channels (those that are diverted for urban use and irrigation along the Colorado River) were in the region of the limit-of-detection (e.g., 10ng/L), but most were below detection limits.

Enhanced Landfill Mining in view of multiple resource recovery: a critical review

a b s t r a c t In a circular economy material loops are closed by recycling of pre-consumer manufacturing scrap/ residues, urban mining of End-of-Life products and land !ll mining of historic (and future) urban waste streams. However, in the past land !ll mining was not performed with a focus on resource recovery. This paper addresses this gap by introducing the concept of Enhanced Land !ll Mining, de !ned as the safe conditioning, excavation and integrated valorization of land !lled waste streams as both materials and energy, using innovative transformation technologies and respecting the most stringent social and ecological criteria. The feasibility of ELFM is studied by synthesizing the research on the Closing the Circle project, the !rst ELFM project targeting the 18 million metric ton land !ll in Houthalen-Helchteren in the East of Belgium. It is argued that Environmental Impact Assessments of ELFM projects should be wide in scope and time. Embedded in a broad resource management perspective, the worldwide potential of ELFM is highlighted, in terms of climate gains, materials and energy utilization, job creation and land reclamation. The potential is quanti !ed for the EU-27 with its 150,000 e500,000 land !lls. However, for ELFM to reach its full potential, strategic policy decisions and tailored support systems, including combined incentives for material recycling, energy utilization and nature restoration, are required.

Waste-Incorporated Subbase for Porous Landscape Detention Basin Design

Porous landscape detention basins (PLDBs) capture and filter storm water while taking advantage of the intrinsic quality of plants to act as water treatment systems. A two-layered subbase filtering medium is recommended for building PLDBs. The current design method creates the opportunity for incorporating waste symbiosis. In this study, the beneficial reuse of mixing urban waste stream materials into the subbase filtering media is identified. Based on the waste screening tests conducted in this study, three mixes were selected and examined for their leaching and clogging potentials over the years of service. They are (1) peat-sand mix, (2) compost-paper-sand mix, and (3) compost-paper-sand-tire mix. Laboratory tests showed no significant differences among these three mixes in infiltration capacity and leaching contents of nutrients, pathogens, and total metals. Subbase clogging tests were also conducted for these three mixes using sample storm water. The decay of clogged infiltration rate was measured as...

Optimizing Urban Material Flows and Waste Streams in Urban Development through Principles of Zero Waste and Sustainable Consumption

Beyond energy efficiency, there are now urgent challenges around the supply of resources, materials, energy, food and water. After debating energy efficiency for the last decade, the focus has shifted to include further resources and material efficiency. In this context, urban farming has emerged as a valid urban design strategy, where food is produced and consumed locally within city boundaries, turning disused sites and underutilized public space into productive urban landscapes and community gardens. Furthermore, such agricultural activities allow for effective composting of organic waste, returning nutrients to the soil and improving biodiversity in the urban environment. Urban farming and resource recovery will help to feed the 9 billion by 2050 (predicted population growth, UN-Habitat forecast 2009). This paper reports on best practice of urban design principles in regard to materials flow, material recovery, adaptive re-use of entire building elements and components (‘design for disassembly’; prefabrication of modular building components), and other relevant strategies to implement zero waste by avoiding waste creation, reducing wasteful consumption and changing behaviour in the design and construction sectors. The paper touches on two important issues in regard to the rapid depletion of the world’s natural resources: the built environment and the education of architects and designers (both topics of further research). The construction and demolition (C&D) sector: Prefabricated multi-story buildings for inner-city living can set new benchmarks for minimizing construction wastage and for modular on-site assembly. Today, the C&D sector is one of the main producers of waste; it does not engage enough with waste minimization, waste avoidance and recycling. Education and research: It’s still unclear how best to introduce a holistic understanding of these challenges and to better teach practical and affordable solutions to architects, urban designers, industrial designers, and so on. How must urban development and construction change and evolve to automatically embed sustainability in the way we design, build, operate, maintain and renew/recycle cities? One of the findings of this paper is that embedding zero-waste requires strong industry leadership, new policies and effective education curricula, as well as raising awareness (through research and education) and refocusing research agendas to bring about attitudinal change and the reduction of wasteful consumption.