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A multi-criteria analysis of building level graywater reuse for personal hygiene – new article co-authored by Timos Karpouzoglou

Timos Karpouzoglou has been with the Division since 2018, and is working closely with the KTH WaterCentre, where he previously was a research coordinator. His current research is focused on urban water infrastructure and is informed by social sciences and the humanities. In a new article, together with Jörgen Wallin (KTH) and Jesper Knutsson (Chalmers), Timos investigates how water demand globally exceeds over available water supply, and takes a closer look at the reuse of bathroom graywater for shower and bathroom sink hot water. The investigation focuses on water and energy savings, water treatment, economic benefit and investigates the main actors and institutions that are involved. “A multi-criteria analysis of building level graywater reuse for personal hygiene” was published in the 2021 December issue of Resources, Conservation & Recycling Advances.
Water Infrastructure. Photo: iStock

Abstract

Globally an increasing number of people are facing water scarcity. To address the challenge, measures to reduce water demand are investigated in the world. In the present paper, a novel approach to reuse bathroom graywater for shower and bathroom sink hot water is investigated. The investigation focuses on water and energy savings, water treatment, economic benefit and investigates the main actors and institutions that are involved.

The main results are that there is significant potential for water and energy savings with a positive economic benefit. Water savings of domestic hot water up to 91 % and energy savings up to 55 % were observed. The investigated treatment plant produces recycled graywater with a quality close to drinking water standards.

The investigation also presents that the reason for the positive economic benefit will depend on the utility tariffs. Therefore, two locations with different utility rate structures were investigated, Gothenburg, Sweden and Settle, USA. In Gothenburg, the utility cost for energy was the driver of economic benefit and in Seattle it was the water and wastewater cost that was the driver. The return of investment for the system and installation was shown to be 3.7 years in Gothenburg and 2.4 years in Seattle.

Keywords

Graywater recovery, Graywater reuse, Heat recovery in graywater, Energy conservation, Water saving, Water reuse, Recycled water

Links:

New Article: Claiming Value in a Heterogeneous Solid Waste Configuration in Kampala

Division and EHL researcher Henrik Ernstson, together with Mary Lawhon, University of Edinburgh and Hakimu Sseviiri, Shuaib Lwasa and Revocatus Twinomuhangib from Makerere University (Urban Action Lab) are published in a forthcoming issue of the scientific journal Urban Geography. In the peer review article “Claiming value in a heterogeneous solid waste configuration in Kampala” they examine recycling in Kampala, the city’s complex waste systems and why little waste moves through it.
Photo: Henrik Ernstson http://www.situatedupe.net/hiccup/hiccup-resources-outputs/

Abstract 

Kampala has a complex set of regulations describing actors, rules and procedures for collection and transportation of waste, and requires waste to be disposed of at the landfill. Yet little of the city’s waste moves through this “formal system”. Building on wider scholarship on urban infrastructure and calls to theorize from southern cities, we examine recycling in Kampala as a heterogeneous infrastructure configuration. Kampala’s lively recycling sector is socially and materially diverse: it is comprised of entrepreneurs, publicprivate partnerships and non-governmental organizations, as well as a range of materials with different properties and value. We articulate how actors assert claims, obtain permissions, build and maintain relationships as they rework flows away from the landfill. We argue that recognizing sociomaterial heterogeneity throughout the waste configuration enables a clearer analysis of contested processes of claiming value from waste. We also demonstrate how these efforts have pressured the state to reconsider the merits of the modern infrastructure ideal as a model for what (good) infrastructure is and ought to be. Various actors assert more heterogeneous alternatives, raising the possibility of alternative modes of infrastructure which might generate better incomes and improve service provision.

This article is a part of the Heterogenous Infrastructure Configurations in Uganda (HICCUP) project, funded by the Swedish Research Council.

Henrik is a long time research fellow of the Environmental Humanities Laboratory and the Division. He is a political ecologist, lecturer at the University of Manchester, world wide resident, honorary associate professor of the University of Cape Town, a postcolonial urbanist and a filmmaker to mention only a few things on a long list of engagements. Keep up with Henrik on Twitter: https://twitter.com/rhizomia

Links

Claiming value in a heterogeneous solid waste configuration in Kampala (open access)

HICCUP project page

Urban Geography

The “Grounding book” is now out! Published as #OpenAccess by MIT Press. “Grounding Urban Natures”.*

by Henrik Ernstson

We won the MIT Press Library Award! Our recently published edited book Grounding Urban Natures: Histories and Futures of Urban Ecologies (2019, MIT Press) can now be downloaded #OpenAccess as a searchable PDF from The MIT-Press website (press link above).

For colleagues with permanent jobs or research funding, consider to (also) buy the real and heavy book because its so nice!

The book provides well-written chapters on urban natures, their social lives, their vibrant matters, and their politics across a varied geography, from the global South to North. Bringing together ethnography and environmental history in a comparative gesture, the chapters are great to teach from as students can trust experienced scholars to unpack the multiplicity of urban nature in narrative form that is kept free from jargon. Let me know if you teach from it through my twitter handle @rhizomia (Henrik Ernstson).

Back cover of Grounding Urban Nature

Front cover of Grounding Urban Nature

The book Grounding Urban Natures unpacks the multiplicity of urban natures across a wide geography, from global South to North. It opens a space to re-think how we think urban environmental politics for the 21st century. Written by leading scholars it is divided in three sections: Unexpected Natures, Popular Natures, and Technological Natures, couched within an Introduction and Conclusion written by the editors Henrik Ernstson and Sverker Sörlin.

The chapters are made for teaching as they contain no jargon. They effectively open up urban natures from a multiple of perspectives, and bring case studies from across the world—from new emergent forms of urbanism of the global South, to re-worked cities in the global North. Students will have a wealth of experience to rely on as urban natures are shown to be shaped in sometimes unexpected ways through:

  • a multiplicity of agencies;
  • the role of historical changes, from colonisation to industrialisation;
  • the impact of race and class structures—but also social movements;
  • the circulation of ideas, from Confucianism to neoliberalism; and
  • the heavy hand of expert models and engineering standards.

Constructive review of urban ecology as an interdisciplinary field from especially the 1990s onward is given in the Introduction. The shear explosion of exciting thinking that have emerged and pushed the humanities and the social and natural sciences to regard urban nature very differently today than simply 20 years back. The Introduction includes debates and tensions between different perspectives from socio-natures, more-than-human, urban political ecology, and social-ecological systems theory (including resilience), which is paired with a close reading of how postcolonial and Southern urbanism, which has grown strongly in urban studies in the last 15 years, can help to open up a space to think urban nature from a wider lens, from a “world of cities” (1).

The chapters are written by leading scholars in the field. This includes chapters from one of the true founders to think cities as socio-natures, Ann Whiston Spirn who wrote The Granite Garden-classic in 1984 and here contributes an intimate chapter on teaching high school kids about landscape literacy in Philadelphia and theorising democratic practices; to Lindsay Sawyer’s chapter on Lagosian’s mode of building auto constructed real-estate; to Martín Ávila (with Henrik Ernstson) on infrastructures and scorpions and the problem of co-habitation in Córdoba, Argentina; how a huge engineering lock made a river disappear in New Orleans by Joshua Lewis; “alien” plant clearing in Chinese Dalian by Lisa M HoffmanAmita Baviskar on parks, forests and couples falling in love in New Delhi; and how Chinese “eco-cities” is linked to massive dispossession of farmers from their land in China by Jia-Ching Chen; and several more chapters from Richard A. WalkerLance van SittertJens Lachmund and James Evans.

Chapters are placed between an Introduction and Conclusion that provides historical background and theory from an expanding field. These chapters opens up a space to re-think urban environments from new locations. With rapid urbanisation and radically new ways through which urban natures are shaped across global South and North, we cannot trust old models nor unreflectively reproduce global models such as “eco-cities,” “smart cities,” “resilience cities,” or a new “science of cities” without paying attention to how place matters. Through a critique of how global discourse tend to homogenise and universalise how we think about cities, the Introduction and Conclusion opens a space to re-think our urban environmental crisis.

This book provides a step to gather a more inclusive and generous practice for thinking and formulating urban environmental policy and activism in the Urban Age of the 21st century. Drawing on the strong resurgence of Southern and postcolonial perspectives in urban studies, we as editors argue for a “comparative urban environmentalism” to create this space of critique and dialogue. The Introduction argues for combining the “wild” libraries of urban socio-nature from the 1990s onward, with postcolonial or “Southern urbanism” from urban studies, to invigorate thinking while decentering the global North as the locus of thought. This opens the global phenomena of rapid urbanisation and environmental crisis to be theorised from more places and disciplines. In the tradition of William Cronon’s edited volume Uncommon Ground, a truly eclectic and somewhat boistorous collection of writers, our “Grounding-book” offers a strong contribution to urban ecology, to environmental humanities, to political ecology, and to environmental thought more generally.

We hope you like it!

Published by MIT Press in their series on Urban and Industrial Environments in August 2019. Made Open Access through the MIT Press Library Award on 7 October 2019.

Contributors: Martín Ávila, Amita Baviskar, Jia-Ching Chen, Henrik Ernstson, James Evans, Lisa M. Hoffman, Jens Lachmund, Joshua Lewis, Lindsay Sawyer, Anne Whiston Spirn, Lance van Sittert, Richard A. Walker.

Editors: Henrik Ernstson and Sverker Sörlin.

(1) The expression is taken from Jennifer Robinson, a founding and generous sister of Southern urbanism. More on that in the Introduction.

*Reprinted with permission from http://www.situatedecologies.net/archives/2225