scholarly journals Nitrate-nitrogen removal with small-scale reverse osmosis, electrodialysis and ion-exchange units in rural areas

Water SA ◽  
2009 ◽  
Vol 35 (5) ◽  
Author(s):  
JJ Schoeman
Keyword(s):  
Ion Exchange ◽  
Reverse Osmosis ◽  
Nitrogen Removal ◽  
Rural Areas ◽  
Nitrate Nitrogen ◽  
Small Scale

Effect of dissolved oxygen conditions on nitrogen removal in continuously fed intermittent-aeration process with two tanks

2002 ◽  
Vol 45 (12) ◽  
pp. 181-188 ◽  
Author(s):  
T. Hidaka ◽  
H. Yamada ◽  
M. Kawamura ◽  
H. Tsuno
Keyword(s):  
Nitrogen Removal ◽  
Rural Areas ◽  
Aerobic Condition ◽  
Small Scale ◽  
Intermittent Aeration ◽  
Solids Retention ◽  
Oxygen Conditions ◽  
Control Set ◽  
Aeration Process ◽  
Biological Nitrogen

In this study, an intermittent aeration type activated sludge process that is fed continuously is evaluated for nitrogen and organic carbon for facilities in rural areas, which are characterized by small scale, low loading rate and automatic operation. Anoxic and aerobic conditions can be regulated alternatively by intermittent aeration for biological nitrogen removal. It is proved that an intermittent aeration cycle of 90 min, with aeration/anoxic mixing periods of 25~30 min/65~60 min in Tank 1, and 30~45 min/60~45 min in Tank 2, and a DO control set at 0.6~1 mg/L during the aeration period are required for satisfactory treatment performance. Under these conditions, a stable effluent water quality with BOD ≤ 5 mg/L, CODMn ≤ 8 mg/L, Nitrogen ≤ 3 mgN/L, SS ≤ 5 mg/L and transparency ≥ 80 cm can be achieved. The solids retention time in aerobic condition was 10~25 d, which is sufficient for nitrification.

Innovative concepts of regeneration of decolorization ion exchange resins in sugar refineries

2016 ◽  
pp. 377-380
Author(s):  
Marc André Théoleyre ◽  
Anne Gonin ◽  
Dominique Paillat
Keyword(s):  
Ion Exchange ◽  
Reverse Osmosis ◽  
Energy Supply ◽  
Ion Exchange Resins ◽  
Salt Solutions ◽  
Nanofiltration Membranes ◽  
Local Conditions ◽  
Salt Consumption ◽  
Multiple Effect ◽  
Exchange Resins

Regeneration of resins used for decolorization of sugar solutions is done with concentrated salt solutions. Nanofiltration membranes have been proven effective, in terms of industrial efficiency in decreasing salt consumption. More than 90% of the salt that is necessary for regeneration can be recycled through a combination of direct recycling of intermediate eluates, the separation of colored compounds by use of very selective nanofiltration membranes and a system to concentrate salty permeates. According to specific local conditions on energy supply and cost, the concentration of salty permeates can be either a multiple effect evaporator or a combination of electrodialysis and reverse osmosis. The desalted color compound solution is sent to the molasses, limiting considerably the effluent to be treated. Starting from a liquor of 800 IU, the water requirement is limited to less than 100 L/t of sugar and the amount of wastewater can be reduced to less than 40 L/t of sugar.

scholarly journals SPEAR (Solar Pyrolysis Energy Access Reactor): Theoretical Design and Evaluation of a Small-Scale Low-Cost Pyrolysis Unit for Implementation in Rural Communities

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2189
Author(s):  
Cesare Caputo ◽  
Ondřej Mašek
Keyword(s):  
Waste Management ◽  
Rural Areas ◽  
Net Present Value ◽  
Agricultural Waste ◽  
Tracking Error ◽  
Sub Saharan Africa ◽  
Small Scale ◽  
Energy Access ◽  
Efficient System ◽  
Pyrolysis Unit

Energy access and waste management are two of the most pressing developmental and environmental issues on a global level to help mitigate the accelerating impacts of climate change. They are particularly relevant in Sub–Saharan Africa where electrification rates are significantly below global averages and rural areas are lacking a formal waste management sector. This paper explores the potential of integrating solar energy into a biomass pyrolysis unit as a potentially synergetic solution to both issues. The full design of a slow pyrolysis batch reactor targeted at biochar production, following a strict cost minimization approach, is presented in light of the relevant considerations. SPEAR is powered using a Cassegrain optics parabolic dish system, integrated into the reactor via a manual tracking system and optically optimized with a Monte-Carlo ray tracing methodology. The design approach employed has led to the development an overall cost efficient system, with the potential to achieve optical efficiencies up 72% under a 1.5° tracking error. The outputs of the system are biochar and electricity, to be used for soil amendment and energy access purposes, respectively. There is potential to pyrolyze a number of agricultural waste streams for the region, producing at least 5 kg of biochar per unit per day depending on the feedstock employed. Financial assessment of SPEAR yields a positive Net Present Value (NPV) in nearly all scenarios evaluated and a reasonable competitiveness with small scale solar for electrification objectives. Finally, SPEAR presents important positive social and environmental externalities and should be feasibly implementable in the region in the near term.

Combining reverse osmosis and ion-exchange allows beet distillery condensates to be recycled as fermentable dilution water

Desalination ◽  
2015 ◽  
Vol 363 ◽  
pp. 75-81 ◽  
Author(s):  
Marie-Laure Lameloise ◽  
Marjorie Gavach ◽  
Marielle Bouix ◽  
Claire Fargues
Keyword(s):  
Ion Exchange ◽  
Reverse Osmosis ◽  
Dilution Water

Reflections on Ecological and Environmental Construction of New Rural Program in Underdeveloped Areas

2011 ◽  
Vol 368-373 ◽  
pp. 3602-3606
Author(s):  
Ze Xin Li ◽  
Min Chen
Keyword(s):  
Rural Areas ◽  
Rural Economy ◽  
Living Environment ◽  
Ecological Environment ◽  
Small Scale ◽  
Environment Protection ◽  
Underdeveloped Areas ◽  
Rural Program ◽  
Rural Construction ◽  
New Rural Construction

Underdeveloped rural areas have good but very vulnerable ecological environment, so the environment protection should be given priority in new rural construction. Based on the problems that rural areas have faced in ecological environment, some thoughts are given in this paper on ecological and environmental: ①To solve the conflicts between the development of rural economy and ecological environment protection, the development of eco-industry can be a key solution. ② For the point that people of underdeveloped areas live in scattered and small scale groups, which leads to difficulty in facility arrangements, some proposals are put forward on the construction of living environment in underdeveloped new rural areas.

scholarly journals Environmental Performance of Small-Scale Seawater Reverse Osmosis Plant for Rural Area Water Supply

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 40
Author(s):  
Latifah Abdul Ghani ◽  
Nora’aini Ali ◽  
Ilyanni Syazira Nazaran ◽  
Marlia M. Hanafiah
Keyword(s):  
Drinking Water ◽  
Global Warming ◽  
Water Supply ◽  
Reverse Osmosis ◽  
Resource Scarcity ◽  
Small Scale ◽  
Seawater Desalination ◽  
Seawater Reverse Osmosis ◽  
Desalination Technology ◽  
The Impact

Seawater desalination is an alternative technology to provide safe drinking water and to solve water issues in an area having low water quality and limited drinking water supply. Currently, reverse osmosis (RO) is commonly used in the desalination technology and experiencing significant growth. The aim of this study was to analyze the environmental impacts of the seawater reverse osmosis (SWRO) plant installed in Kampung Pantai Senok, Kelantan, as this plant was the first installed in Malaysia. The software SimaPro 8.5 together with the ReCiPe 2016 database were used as tools to evaluate the life cycle assessment (LCA) of the SWRO plant. The results showed that the impact of global warming (3.90 kg CO2 eq/year) was the highest, followed by terrestrial ecotoxicity (1.62 kg 1,4-DCB/year) and fossil resource scarcity (1.29 kg oil eq/year). The impact of global warming was caused by the natural gas used to generate the electricity, mainly during the RO process. Reducing the environmental impact can be effectively achieved by decreasing the electricity usage for the seawater desalination process. As a suggestion, electricity generation can be overcome by using a high-flux membrane with other suitable renewable energy for the plant such as solar and wind energy.

Modeling of small scale reverse osmosis systems

Desalination ◽  
1985 ◽  
Vol 52 (3) ◽  
pp. 267-284 ◽  
Author(s):  
C.S. Slater ◽  
J.M. Zielinski ◽  
R.G. Wendel ◽  
C.G. Uchrin
Keyword(s):  
Reverse Osmosis ◽  
Small Scale

scholarly journals Using network analysis to analyse the complex interaction of factors causing the failure of small-scale water infrastructure (SWI) in the rural areas of South Africa

Water SA ◽  
2018 ◽  
Vol 44 (3 July) ◽  
Author(s):  
DC Sambo ◽  
A Senzanje ◽  
K Dhavu
Keyword(s):  
South Africa ◽  
Rural Communities ◽  
Rural Areas ◽  
Small Scale ◽  
Research Approach ◽  
Water Services ◽  
Systematic Analysis ◽  
Complex Interactions ◽  
Technical Community ◽  
Drying Up

Some parts of the rural areas of South Africa are receiving water services below the legislative standards stipulated in the Water Services Act (1997) of South Africa. This is because small-scale water infrastructures (SWI), including standpipes, handpumps and windmills, are failing to supply adequate water in rural communities for various activities that enhance their livelihoods. This is due to technical, community, institutional, and environmental factors. Literature indicates that these factors are complex in nature. However, research on their complex interactions has been limited. Therefore, the complex interactions of the factors causing SWI failure were investigated and analysed in this study. A qualitative research approach was employed to investigate the factors that cause failure of SWI. The network approach combined with graph theory and the community structure method were used to generate a theme and domain network that allowed for a systematic analysis and interpretation of the causes of SWI failure in the study area. The major causes of failure identified include: (i) the use of a top-down approach to implement water projects in rural communities without consultation, (ii) sharing of SWI in high numbers due to the limited number of SWI available/functional, resulting in overloading and increased breakdowns, and (iii) drying up of water sources due to poor siting leading to vandalism of SWI. Overall, the causes of SWI failure are as a result of the complex interactions of different categories of factors. The theme and domain network is a powerful tool that can be used represent and analyse the complex interactions. It is therefore imperative for interventions aiming to improve rural water supply to analyse the complex interactions of the causes of SWI failure to understand the underlying problems at a level of a system, in order to propose suitable solutions.

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