Small water and wastewater systems: pathways to sustainable development?

2004 ◽  
Vol 48 (11-12) ◽  
pp. 7-14 ◽  
Author(s):  
G. Ho
Keyword(s):  
Sustainable Development ◽  
Large Scale ◽  
Small Scale ◽  
Technology Choice ◽  
Large Scale Systems ◽  
Environmentally Sustainable ◽  
Small Water ◽  
Developing Communities ◽  
Wastewater Systems ◽  
Water And Wastewater

Globally we are faced with billions of people without access to safe water and adequate sanitation. These are generally located in developing communities. Even in developed communities the current large scale systems for supplying water, collecting wastewater and treating it are not environmentally sustainable, because it is difficult to close the cycle of water and nutrients. This paper discusses the advantages of small scale water and wastewater systems in overcoming the difficulties in providing water and wastewater systems in developing communities and in achieving sustainability in both developed and developing communities. Particular attention is given to technology and technology choice, even though technology alone does not provide the complete answer. Disadvantages of small scale systems and how they may be overcome are discussed.

Kinetics, mass transfer, and mass re-equilibrium for arsenate adsorption on iron oxide-based carbons

2018 ◽  
Author(s):  
◽  
Zhengyang Wang
Keyword(s):  
Mass Transfer ◽  
Water Treatment ◽  
Large Scale ◽  
Freundlich Isotherm ◽  
Small Scale ◽  
Crossover Point ◽  
Hydraulic Residence Time ◽  
In Situ Extraction ◽  
Small Water ◽  
Batch Tests

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Removal of arsenic (As) from drinking water sources is much needed worldwide, and small water treatment systems, such as point-of-use (POU) treatment, could be an effective solution for residential applications. Adopting existing removal technologies that are successful in large-scale treatment to small-scale units, however, is rather ineffective due to the short hydraulic residence time in small water treatment systems. … The Freundlich isotherm can fit experimental data well: a crossover point for the two fitted Freundlich isotherms was observed and nano-FeAC had higher adsorption plateau. Furthermore, we demonstrated that due to the MRE process, a pseudo-equilibrium of FeMC was altered to another steady state by an in situ extraction with nano-FeAC in both batch and column systems. The overall inter-medium mass transfer resulted in both improved adsorption densities obtained by batch tests and a large bed volume prior to the 10 [mu]g As/L breakthrough at a short empty bed contact time (0.85 min).

scholarly journals Geographical and logistical factors of sustainable development of rural tourism in the context of regional economy

2016 ◽  
pp. 9-14
Author(s):  
I. Smyrnov
Keyword(s):  
Sustainable Development ◽  
Large Scale ◽  
Regional Economy ◽  
Local Economy ◽  
Rural Tourism ◽  
Small Scale ◽  
Resource Base ◽  
Tourist Flows ◽  
Definition Of ◽  
The Impact

Rural tourism is now seen as an important direction of development of the regional economy. From the perspective of sustainable development rural tourism affects the economic, social and environmental aspects of the regional and local economy. Rural tourism is closely linked with agrotourism, eco-tourism, natural tourism and so on. Sustainable rural tourism can be realized by applying logistic, geographic and marketing approaches as components of sustainable development strategies. Logistics approach is determined by logistic potential of resource base of rural tourism and appropriate tourist flows regulation. In this context in the article the concept of tourism capacity or capacity of the resource base of rural tourism is used. The problem of the definition of tourism pressure on the resource base of rural tourism, particularly in natural landscapes is disclosed. Unlike environmental and recrealogical sciences, which stop at the capacity definition of the resource base of tourism, tourism logistics compares this figure with the existing tourist flows and accordingly determines the safe way of tourism management to ensure its sustainable nature. It was shown that these strategies boil down to two basic types – the further development of tourism in a particular area or limit such activities to conserve the resource base of tourism. Recreational (travel) load is the indicator that reflects the impact of tourism on the resource base of tourism (especially landscape complex), expressed by the number of tourists or tourists-days per area unit or per tourist site for the certain period of time (day, month, season year). There are actual, allowable (the maximum) and destructive (dangerous) types of travel load. The latter can lead recreational area or resource base of rural tourism to destruction. Thus, depending on the intensity of tourism resource base using in rural tourism it may change – according to tourist consumption. Large number of tourists affects the entire range of recreational destinations and their individual components. The most vulnerable part of the environment in this sense is vegetation, except that significant changes may occur with soil, water bodies, air and so on. The geographic dimension of the problem of rural tourism sustainable development includes the concept of zoning, ie the division of the territory, offering to develop rural tourism in several zones with different modes of travel usage – from a total ban (in protected areas) for complete freedom with transitional stages, involving various limit degrees in the development of rural tourism. Marketing approach reflects the application of the curve R. Butler to the stages of development of rural tourism destinations with the release of such steps as: research, involvement, development, consolidation, stagnation (also called “saturation”), revival or decline. Shown the models that link the stage of resource base tourist development (under “Curve Butler”), strength of tourism consumption the magnitude of such effects (eg weak (disperse) impact in large scale, strong (concentrated) impact in large scale, strong (concentrated) impact in small scale, weak (disperse) impact in small scale), dynamics of tourism development at the territory.

scholarly journals Extensive deep neural networks for transferring small scale learning to large scale systems

2019 ◽  
Vol 10 (15) ◽  
pp. 4129-4140 ◽  
Author(s):  
Kyle Mills ◽  
Kevin Ryczko ◽  
Iryna Luchak ◽  
Adam Domurad ◽  
Chris Beeler ◽  
...  
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Large Scale ◽  
Deep Neural Network ◽  
Deep Neural Networks ◽  
Small Scale ◽  
Large Scale Systems ◽  
Energy Entropy ◽  
Large Systems ◽  
Number Of Particles

We present a physically-motivated topology of a deep neural network that can efficiently infer extensive parameters (such as energy, entropy, or number of particles) of arbitrarily large systems, doing so with scaling.

Environmental assessment and cost estimation of drinking water and wastewater systems for transition areas in Sweden

2008 ◽  
Vol 57 (12) ◽  
pp. 2039-2042
Author(s):  
A. Norström ◽  
Å. Erlandsson ◽  
E. Kärrman
Keyword(s):  
Cost Estimation ◽  
Large Scale ◽  
Flow Analysis ◽  
Total Annual Cost ◽  
Wastewater Systems ◽  
Water And Wastewater ◽  
Peripheral Areas ◽  
The Baltic ◽  
The Cost ◽  
Transition Areas

In the Stockholm region there are around 90,000 households with single systems. These households cause larger phosphorus flows to the Baltic Sea than the 1.8 million people connected to four advanced large-scale treatment plants in the same region. According to city plans, some of these areas with on-site systems in transition to permanent living shall be connected to central systems. The problem is however that this sewer system will take decades to complete. It is also not ensured whether or not all peripheral areas with on-site systems could be connected to the central systems. To help support environmental decisions for the selection of wastewater systems for these areas, an Excel-based model has been developed where the cost for the systems can be assessed and evaluated in relation to their environmental impact. The model deals with two types of environmental issues: substance flow analysis and energy analysis. The cost part considers investigations, investments, design, operation, maintenance and supervision, and calculates total annual cost for the water and wastewater system per person.

scholarly journals Performance Evaluation of Small-Scale Solar Powered Wastewater and Grey Water Treatment Systems

2015 ◽  
Vol 07 (1) ◽  
Keyword(s):  
Ammonia Nitrogen ◽  
Optimum Operating ◽  
Small Scale ◽  
Energy Usage ◽  
Optimum Operating Condition ◽  
Environmentally Sustainable ◽  
Onsite Wastewater Treatment Systems ◽  
Water And Wastewater ◽  
Effluent Discharge ◽  
Solar Powered

Onsite wastewater treatment systems are the most economical way of dealing with used water in an isolated environment. And because of the variability normally associated with the operation of these systems is linked to either varying hydraulic loading or the nature of the environment in which the system was installed, the performance of these systems needs to be evaluated to find out the optimum operating condition. In this work, the performance of two small-scale treatment systems used for wastewater and gray water was evaluated. This was done by comparing the measure of some physical, chemical and biological parameters in the effluent to the standards of effluent discharge sets by Dubai Municipality. The performance was also measured from other angles using the proposed Swedish Water and Wastewater Association performance indicators so as to give the analysis a wider coverage of economic and energy consumption. The result shows that the performance of the installed solar-powered treatment systems was enough to meet the requirements set by Dubai municipality for effluent discharge except for Ammonia-Nitrogen. Also, the deployment of solar power energy supply, coupled with a low energy usage of the two systems, has made this particular setting an environmentally sustainable setting for such an isolated site.

Overview of Accelerator Applications in Energy

2015 ◽  
Vol 08 ◽  
pp. 1-25 ◽  
Author(s):  
Robert W. Garnett ◽  
Richard L. Sheffield
Keyword(s):  
Large Scale ◽  
Oil And Gas ◽  
High Energy ◽  
Small Scale ◽  
Future Directions ◽  
Industrial Systems ◽  
Large Scale Systems ◽  
Oil And Gas Exploration ◽  
Exploration And Production ◽  
Accelerator Technology

An overview of the application of accelerators and accelerator technology in energy is presented. Applications span a broad range of cost, size, and complexity and include large-scale systems requiring high-power or high-energy accelerators to drive subcritical reactors for energy production or waste transmutation, as well as small-scale industrial systems used to improve oil and gas exploration and production. The enabling accelerator technologies will also be reviewed and future directions discussed.

scholarly journals Spatial Contrast of Geographically Induced Rainfall Observed by TRMM PR

2017 ◽  
Vol 30 (11) ◽  
pp. 4165-4184 ◽  
Author(s):  
Masafumi Hirose ◽  
Yukari N. Takayabu ◽  
Atsushi Hamada ◽  
Shoichi Shige ◽  
Munehisa K. Yamamoto
Keyword(s):  
Large Scale ◽  
Tropical Rainfall Measuring Mission ◽  
Small Scale ◽  
Small Islands ◽  
Large Scale Systems ◽  
Medium Scale ◽  
Orographic Rainfall ◽  
Hourly Data ◽  
High Concentrations ◽  
The Tropics

Abstract In this study, the spatial variability in precipitation at a 0.1° scale is investigated using long-term data from the Tropical Rainfall Measuring Mission Precipitation Radar. Marked regional heterogeneities emerged for orographic rainfall on characteristic scales of tens of kilometers, high concentrations of small-scale systems (<10 km) over alpine areas, and sharp declines around mountain summits. In detecting microclimates, an additional concern is suspicious echoes observed around certain geographical areas with relatively low rainfall. A finescale land–river contrast can be extracted in the diurnal behavior of rainfall in medium-scale systems (10–100 km), corresponding to the course of the Amazon River. In addition, rainfall enhancement over small islands (0.1°–1°) was identified in terms of the storm scale. Even 0.1°-scale flat islands experience more rainfall than the adjacent ocean, primarily as a result of localized small or moderate systems. By contrast, compared with small islands, high-impact large-scale systems (>100 km) result in more rainfall over the adjacent ocean. Finescale hourly data represented the abrupt asymmetric fluctuation in rainfall across the coastline in the tropics and subtropics (30°S–30°N). Significant diurnal modulations in the rainfall due to large-scale systems are found over tropical offshore regions of vast landmasses but not over small islands or in the midlatitudes between 30° and 36°. Rainfall enhancement over small tropical islands is generated by abundant afternoon rainfall, which results from medium-scale storms that are regulated by the island size and inactivity of rainfall over coastal waters.

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