215 research outputs found
A Caribbean evaluation of public versus private drinking water provision: the case of St. Maarten, Netherlands Antilles
This article assesses how a small island state can choose the best option in the process of private sector involvement. It reviews the decision process to involve or not the private sector in water and sanitation supply and in which way. Nine criteria are used to make the choice. A careful weighing process is necessary, taking the history into account, looking at the special institutional situation in the country and involving the stakeholders, and even then there is no guarantee of success! An existing public utility may be better placed to look after the modernisation and extension of the water and sanitation system than a new private firm
A Case Study of Excreta Disposal Following the 2006 Java Earthquake*
Providing safe excreta disposal following disasters is important for disease prevention and the safety and dignity of the affected population. This is challenging because every emergency varies due to the nature of the disaster, local conditions and the characteristics of the affected population. This paper investigates the impact of the 2006 Java earthquake on excreta disposal needs and the response to those needs. Relevant documents were retrieved from the ReliefWeb database, complemented by a literature search. The case study highlights gaps in rapidly providing latrines on a large scale. Three months after the disaster, only 57% of the latrines targeted had been provided. One way to address this problem is to better understand the factors affecting excreta disposal needs and response, allowing appropriate solutions to be identified more effectively
Function-feature analysis of emergency sanitation technologies: towards systematic innovation
There has been increased recognition of the need for innovation in emergency sanitation products and technologies. To support effective design, this paper explores an approach systematically innovate by framing the problem from the perspective of the functions (the desired outcomes of a design) that features (characteristics of a design) achieve. The paper illustrates examples of how such functions can be identified: by analysing existing designs, studying the literature and drawing lessons learned from case studies. Functions may be interrelated and vary in nature and importance in different circumstances. Functions can be achieved by implementing one or more design features. At the same time, features can contribute to achieving one or more functions. By understanding and consolidating all possible functions and features, this approach can support innovation in several ways, most fundamentally by ensuring that important design considerations are not overlooked during the product development process
A Case Study of Excreta Disposal Following the 2006 Java Earthquake*
Providing safe excreta disposal following disasters is important for disease prevention and the safety and dignity of the affected population. This is challenging because every emergency varies due to the nature of the disaster, local conditions and the characteristics of the affected population. This paper investigates the impact of the 2006 Java earthquake on excreta disposal needs and the response to those needs. Relevant documents were retrieved from the ReliefWeb database, complemented by a literature search. The case study highlights gaps in rapidly providing latrines on a large scale. Three months after the disaster, only 57% of the latrines targeted had been provided. One way to address this problem is to better understand the factors affecting excreta disposal needs and response, allowing appropriate solutions to be identified more effectively
Wastewater re-use for peri-urban agriculture: a viable option for adaptive water management?
Urbanization is known to spur land modification in the form of conversion of common land to human settlements. This factor, combined with climate variability, can alter the duration, frequency and intensity of storm drain overflows in urban areas and lead to public health risks. In peri-urban regions where these risks are especially high it has been argued that, when domestic wastewater is managed, better prospects for freshwater water savings through swaps between urban water supply and irrigated agriculture may be possible. As a consequence of re-use of domestic wastewater, expenditure on inorganic inputs by farmers may decline and source sustainability of water supply could be enhanced. Given the fact that, at present, approximately 20 million ha of land worldwide is being cultivated by re-using domestic wastewater, this paper draws on evidence from India to explore: (1) the economic costs-benefits of wastewater reuse in the context of hypothesized links to climate variability; (2) the role of local farming practices, market conditions and crop variety in influencing wastewater reuse in agriculture; and (3) the role of inter-governmental financing in influencing the selection of technical adaptation options for collection, treatment and disposal of wastewater.ASC – Publicaties niet-programma gebonde
Emergency toilets for the people affected by the Mount Sinabung eruptions
Mount Sinabung erupted in September 2013, causing the mass evacuation of more than 30,000 people. Evacuees were placed in public buildings such as churches, mosques, schools and universities, as well as tent camps. Pour-flush toilets were provided by the government. However, the level of provision was generally inadequate. The continuity of water was a major concern, with the people relying on water trucks for the supply of water. Toilets were not properly maintained and rubbish was found around toilets, which could clog drainage channels. Insufficient cleaning tools were provided. Coverage far exceeded generally accepted targets of twenty people per toilet. To address these issues, water supply should be closely monitored, additional toilets installed, adequate cleaning tools should be provided and people should be better organised to maintain toilets
Effect of Lactate on the Microbial Community and Process Performance of an EBPR System
Candidatus Accumulibacter phosphatis is in general presented as the dominant organism responsible for the biological removal of phosphorus in activated sludge wastewater treatment plants. Lab-scale enhanced biological phosphorus removal (EBPR) studies, usually use acetate as carbon source. However, the complexity of the carbon sources present in wastewater could allow other potential poly-phosphate accumulating organism (PAOs), such as putative fermentative PAOs (e.g., Tetrasphaera), to proliferate in coexistence or competition with Ca. Accumulibacter. This research assessed the effects of lactate on microbial selection and process performance of an EBPR lab-scale study. The addition of lactate resulted in the coexistence of Ca. Accumulibacter and Tetrasphaera in a single EBPR reactor. An increase in anaerobic glycogen consumption from 1.17 to 2.96 C-mol/L and anaerobic PHV formation from 0.44 to 0.87 PHV/PHA C-mol/C-mol corresponded to the increase in the influent lactate concentration. The dominant metabolism shifted from a polyphosphate-accumulating metabolism (PAM) to a glycogen accumulating metabolism (GAM) without EBPR activity. However, despite the GAM, traditional glycogen accumulating organisms (GAOs; Candidatus Competibacter phosphatis and Defluvicoccus) were not detected. Instead, the 16s RNA amplicon analysis showed that the genera Tetrasphaera was the dominant organism, while a quantification based on FISH-biovolume indicated that Ca. Accumulibacter remained the dominant organism, indicating certain discrepancies between these microbial analytical methods. Despite the discrepancies between these microbial analytical methods, neither Ca. Accumulibacter nor Tetrasphaera performed biological phosphorus removal by utilizing lactate as carbon source
Flood Resilience Assessment In Urban Drainage Systems Through Multi-Objective Optimisation
In future years, economic development, urbanisation and heavy rainfall events are expected to increase in urban areas, in particular in developing countries. It is well known that urban development has a strong impact on the water cycle such as increase of flood peaks and volume, decrease of base flow, hydraulic stress and water pollution. Resilience measures are still needed to improve urban flood risk, the possibilities to provide indicators that could be used to characterize urban resilience related to flooding is outmost importance. The work described here presents an optimisation framework for urban drainage rehabilitation that incorporates in the decision space the concept of resilience in order to find an optimal rehabilitation strategy. The approach has been tested in the City of Dhaka, Bangladesh by coupling 1D/2D model of the drainage system and linked within the optimisation algorithm. The preliminary results obtained suggest that the proposed approach could be effective in order to reach acceptable level of flood resilience of urban drainage systems, balancing investment and risk within the systems. Further work is recommended to expand and generalize the methodology
“Candidatus Accumulibacter delftensis”:A clade IC novel polyphosphate-accumulating organism without denitrifying activity on nitrate
Long-term effects of sulphide on the enhanced biological removal of phosphorus:The symbiotic role of Thiothrix caldifontis
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