Khosrow Farahbakhsh

Systems approaches to integrated solid waste management in developing countries

Solid waste management (SWM) has become an issue of increasing global concern as urban populations continue to rise and consumption patterns change. The health and environmental implications associated with SWM are mounting in urgency, particularly in the context of developing countries. While systems analyses largely targeting well-defined, engineered systems have been used to help SWM agencies in industrialized countries since the 1960s, collection and removal dominate the SWM sector in developing countries. This review contrasts the history and current paradigms of SWM practices and policies in industrialized countries with the current challenges and complexities faced in developing country SWM. In industrialized countries, public health, environment, resource scarcity, climate change, and public awareness and participation have acted as SWM drivers towards the current paradigm of integrated SWM. However, urbanization, inequality, and economic growth; cultural and socio-economic aspects; policy, governance, and institutional issues; and international influences have complicated SWM in developing countries. This has limited the applicability of approaches that were successful along the SWM development trajectories of industrialized countries. This review demonstrates the importance of founding new SWM approaches for developing country contexts in post-normal science and complex, adaptive systems thinking.

Fate of Endocrine-Active Compounds during Municipal Biosolids Treatment: A Review

For two decades, the fates of endocrine-disrupting compounds (EDCs) across various wastewater treatment processes have been studied using chemical and in vitro bioassay measurements. In comparison, little work has been conducted to track the fates of EDCs during municipal biosolids stabilization, particularly using bioassay approaches. This leads to knowledge gaps with respect to understanding which single or combined biosolid treatments facilitate EDC removal, and what the total endocrine-active potency of treated biosolids might be. These unknowns in turn heighten public opposition and distrust of biosolids reuse applications. This review aims to summarize what is currently known regarding EDC removal during commonly used full-scale biosolids treatment processes and highlights analytical challenges that are relevant when in vitro bioassays and chemical analyses are applied to biosolids samples.

A critical evaluation of two point-of-use water treatment technologies: can they provide water that meets WHO drinking water guidelines?

Point-of-use (POU) technologies have been proposed as solutions for meeting the Millennium Development Goal (MDG) for safe water. They reduce the risk of contamination between the water source and the home, by providing treatment at the household level. This study examined two POU technologies commonly used around the world: BioSand and ceramic filters. While the health benefits in terms of diarrhoeal disease reduction have been fairly well documented for both technologies, little research has focused on the ability of these technologies to treat other contaminants that pose health concerns, including the potential for formation of contaminants as a result of POU treatment. These technologies have not been rigorously tested to see if they meet World Health Organization (WHO) drinking water guidelines. A study was developed to evaluate POU BioSand and ceramic filters in terms of microbiological and chemical quality of the treated water. The following parameters were monitored on filters in rural Cambodia over a six-month period: iron, manganese, fluoride, nitrate, nitrite and Escherichia coli. The results revealed that these technologies are not capable of consistently meeting all of the WHO drinking water guidelines for these parameters.

Nitrification, denitrification and ammonification in point-of-use biosand filters in rural Cambodia

In order to address the United Nations Millennium Development Goal (MDG) target #7 for water and sanitation, the World Health Organization (WHO) has identified point-of-use (POU) water treatment technologies as an option for providing safe water to households. The BioSand filter (BSF) is a commonly used POU system that has been implemented in Cambodia and over 20 countries worldwide. While the health benefits of using a BSF in terms of reduction of diarrheal disease have been fairly well documented, little research has focused on the ability of this technology to treat for other contaminants that could pose health concerns. To address these concerns, a study was developed to evaluate this technology in rural Cambodia in terms of microbiological and chemical quality of the treated water. The study revealed that simultaneous nitrification and denitrification is occurring inside the BioSand filters. Nitrite concentrations in treated water consistently exceeded WHO guidelines. Seventeen of 20 filters on average did not meet the 3.0 mg l(-1) NO2- guideline and the combined nitrate-nitrite guideline ratio of 1. Denitrification seemed to predominate when BSFs were fed surface water. In addition, nitrate-ammonification occurred in some filters fed surface water, causing increases in ammonia in treated water.

Community-based adaptation research in the Canadian Arctic

Community‐based adaptation (CBA) has emerged over the last decade as an approach to empowering communities to plan for and cope with the impacts of climate change. While such approaches have been widely advocated, few have critically examined the tensions and challenges that CBA brings. Responding to this gap, this article critically examines the use of CBA approaches with Inuit communities in Canada. We suggest that CBA holds significant promise to make adaptation research more democratic and responsive to local needs, providing a basis for developing locally appropriate adaptations based on local/indigenous and Western knowledge. Yet, we argue that CBA is not a panacea, and its common portrayal as such obscures its limitations, nuances, and challenges. Indeed, if uncritically adopted, CBA can potentially lead to maladaptation, may be inappropriate in some instances, can legitimize outside intervention and control, and may further marginalize communities. We identify responsibilities for researchers engaging in CBA work to manage these challenges, emphasizing the centrality of how knowledge is generated, the need for project flexibility and openness to change, and the importance of ensuring partnerships between researchers and communities are transparent. Researchers also need to be realistic about what CBA can achieve, and should not assume that research has a positive role to play in community adaptation just because it utilizes participatory approaches. WIREs Clim Change 2016, 7:175–191. doi: 10.1002/wcc.376 For further resources related to this article, please visit the WIREs website.

Overcoming the toxicity effects of municipal wastewater sludge and biosolid extracts in the Yeast Estrogen Screen (YES) assay.

For nearly two decades, the Yeast Estrogen Screen (YES) has been used as a valuable tool for determining the total estrogenic potency of various environmental samples, including influent and effluent streams at municipal wastewater plants. However, applying the YES assay to wastewater sludges and stabilized biosolids has been problematic. This is due to co-extracted compounds from the solids either proving toxic to the yeast or masking the presence of estrogenic substances. The present research describes the development and validation of sample preparation steps that mitigate the toxicity effects of municipal wastewater sludge and biosolid samples in the YES assay, while allowing for reliable dose-dependent expression of estrogenic activity. A copper work-up for sulfur removal and chromatographic cleanup with silica and alumina were required in addition to solid-phase extraction to adequately remove interfering compounds. Sample stabilization methods such as autoclaving, lyophilization and formaldehyde treatment were found to be detrimental to the assay. Hence, heat-drying is recommended to prevent cytotoxicity and the degradation of estrogenic substances.

Dimensionamento de reservatório para aproveitamento de água de chuva: comparação entre métodos da ABNT NBR 15527:2007 e Decreto Municipal 293/2006 de Curitiba, PR

Este trabalho apresenta uma comparacao entre os metodos de dimensionamento de reservatorio de agua de chuva propostos na NBR 15527/2007 e no Decreto Municipal 293/2006, de Curitiba-PR. Para esta analise foram selecionadas cinco edificacoes que possuem sistema de captacao e aproveitamento de agua de chuva em funcionamento. Os resultados obtidos atraves dos dois metodos foram discrepantes. A fim de resultarem volumes coerentes com o aproveitamento de agua de chuva, as equacoes do Decreto Municipal 293/2006 merecem uma revisao, para serem incluidas as consideracoes sobre indice pluviometrico, area de captacao e demanda para a agua de chuva armazenada. A utilizacao dos metodos apresentados na NBR 15527/2007 seria facilitada com ajustes de nomenclatura e inclusao de mais informacoes na apresentacao das equacoes, em funcao da ambiguidade de denominacao das variaveis. A decisao final sobre qual metodo mais indicado pode ser baseada na comparacao dos volumes obtidos e na viabilidade em termos de area disponivel e custo de construcao do reservatorio.

Identifying Barriers to Widespread Implementation of Rainwater Harvesting for Urban Household Use in Ontario

The use of stormwater runoff for domestic purposes (rainwater harvesting; RWH) is increasing as part of the green building movement; however, significant barriers impede the widespread uptake of the technology. This paper reports on the results of stakeholder interviews conducted with representatives from municipal administrations, the building sector and commercial suppliers, identifying barriers faced by each party in implementing RWH. The most significant barriers were as follows: initial capital cost, liability for potential health risks, limitations on the end use of rainwater, the Building Code’s poor differentiation between rainwater, greywater and non-potable water, and a lack of public environmental commitment. Health risks would be a paramount concern for public health officials, but were only a moderate concern for the majority of building practitioners interviewed. These barriers are elaborated upon and discussed in the context of technological lock-in of conventional water management systems and the resulting lack of capacity in alternate water management approaches. Flexible, iterative, reflective, and participatory processes are required to build capacity for sustainable urban water management.

Effects of total suspended solids loading on short-term fouling in the treatment of secondary effluent by an immersed ultrafiltration pilot system.

This study examined the performance of a pilot-scale immersed ultrafiltration system using secondary effluent as a feed source, with particular emphasis on the role played by total suspended solids (TSS) on short-term fouling rates within permeation cycles. Key secondary effluent quality characteristics, such as ionic composition and total/ colloidal organic carbon content, remained reasonably stable during the course of the study. However, TSS loads in the secondary effluent were correlated with the extent of within-cycle fouling. This relationship existed irrespective of membrane packing density or the operating flux, although the latter parameter did control the rate at which within-cycle fouling occurred. Although the complex causes of ultrafiltration membrane fouling during tertiary treatment over the long term remain poorly understood, TSS levels in the feed may offer a simple means of better predicting within-cycle spikes in transmembrane pressure. Based on historical and seasonal trends, or both, of TSS loads in the secondary clarifiers of a given wastewater treatment plant, periods requiring an increased frequency of backpulses or recovery cleanings may be identified before implementation of full-scale tertiary ultrafiltration systems.

How are perceptions associated with water consumption in Canadian Inuit? A cross-sectional survey in Rigolet, Labrador

Concerns regarding the safety and aesthetic qualities of ones municipal drinking water supply are important factors influencing drinking water perceptions and consumption patterns (i.e. sources used and daily volume of consumption). In northern Canada, Inuit communities face challenges with drinking water quality, and many Inuit have reported concerns regarding the safety of their drinking water. The objectives of this research were to describe perceptions of municipal tap water, examine use of water sources and changes following the installation of a potable water dispensing unit (PWDU) in 2014, and identify factors associated with water consumption in the Inuit community of Rigolet. This study used data from three cross-sectional census surveys conducted between 2012 and 2014. Principal component analysis (PCA) was used to aggregate data from multiple variables related to perceptions of water, and logistic regressions were used to identify variables associated with water consumption patterns. Three quarters of residents reported using the PWDU after its installation, with concomitant declines reported in consumption of bottled, tap, and brook water. Negative perceptions of tap water were associated with lower odds of consuming tap water (ORPCAcomponent1=0.73, 95% CI 0.56-0.94; ORPCAcomponent2=0.67, 95% CI 0.49-0.93); women had higher odds of drinking purchased water compared to men (OR=1.90, 95% CI 1.11-3.26). The median amount of water consumed per day was 1L. Using brook water (OR=2.60, 95% CI 1.22-5.56) and living in a household where no one had full-time employment (OR=2.94, 95% CI 1.35-6.39) were associated with consuming >2L of water per day. Results of this study may inform drinking water interventions, risk assessments, and public health messaging in Rigolet and other Indigenous communities.