Furthermore, the study aims to determine the size of components involved in the reverse osmosis process and the size of the renewable energy system that supplies the plant. The next phase focuses on the feasibility of the renewable energy system to meet the reverse osmosis process power requirement.
Introduction
Africa's Current Water Situation
According to the World Bank, by 2012, the rest of the African continent, except for sub-Saharan Africa, is expected to meet water resource targets. The scarcity of water resources in Africa is caused by natural phenomena and low development and development of water resources.
South Africa's Current Water Situation
- Solve the problem of insufficient rural access
- Solving the problem of inefficient water use and management
SADWAF cannot tell if a water cable is broken or when a water main is broken if it does not monitor the amount of water used. In addition to lost or stolen water, South Africa also loses more than 1.5 billion cubic meters of water each year due to the failure of pipeline infrastructure that has exceeded its useful life (Hove et al., 2019).
Statement of Research Problem
Aim and Objectives of the research
Organization of the Thesis
Topics such as the system description, the design methodology for the reverse osmosis water treatment and the design methodology for the solar power system are considered.
Introduction
Renewable energy resources for water technologies
- Solar Energy
- Wind Energy
- Wave Energy
- Tidal Energy
- Small-Scale Hydropower
- Geothermal Energy
- Renewable Energy Powering Water Technologies
In the solar thermal process, solar energy is converted into thermal energy for commercial and domestic applications such as cooling, heating, cooking, drying, etc. Four types of concentrating solar technologies can be found on the market, namely (Romero & González-Aguilar Parabolic trough collectors that collect sunlight into a receiving tube filled with a working fluid).
Water Quality norms
Water Pumping
- Characteristics of pumping
- Pumping efficiency
- Solar pumping system
Or, if the pipe is very narrow, the speed of the water increases faster as the flow rate increases. The pump efficiency depends on the flow rate and the design of the pump.
Water purification
- Underground water
- Saline water
- Polluted water
- Water purification technologies
However, it can affect the taste and smell of water and present health-related concerns. It can be purchased or produced locally; however, hydrogen is also produced (Saqib et al., 2018). Ozone is added to the water in the contact chamber and the main function of the destroyer is to limit the amount of ozone removed into the air.
The schematic diagram of the mechanical vapor compression water desalination system is shown in Figure 2.13. The internal solar seawater desalination device continues to raise the temperature of the brine in the basin. The water obtained is pure, and a small amount of mineral sand can be added to improve it and reduce the corrosivity of the material (WHO, 2012).
Introduction
Water accessibility and resources in South Africa
Wastewater reuse
Access to water and sanitation
In 2015, the total number of people in South Africa without access to improved sanitation facilities was 18 million (UNICEF & WHO, 2015). According to a Joint Water Supply and Sanitation Monitoring Program study and data recording, the percentage of South Africans who received improved sterilization techniques increased gradually from 71% in 1990 to 75% in 2000 and 79%. In 2010, it was estimated that 11 million South Africans will not come close to improving sanitation levels (JMP, 2021).
According to 2011 South African statistics, access to sanitation facilities increased from 83% in 2001 to 91% in 2011, including shared and separate pit latrines and chemical latrines (Kings, 2017).
Water quality and continuity of supply
Wastewater treatment
Water and sanitation stakeholders
Regulation and Policy
Service provision
The price range of the TransCaledon Tunnel Authority and the development of a large number of water supply infrastructures and dams. Under the Constitution, Municipal Structures Act and the Water Supply Act 1997 (Republic of South Africa, 1997), the Water Supply Authority bears the water supply and sanitation obligations. In many cases, the district municipality is the water supply entity, but the national authority may delegate service delivery obligations to the local municipality.
There are 169 water supply agencies, water offices, district municipalities, local municipalities and municipal companies in South Africa. The Constitution of 1996 strengthened the autonomy of the municipalities so that rural water supply and sanitation facilities were transferred from national to municipal authorities. The Southern African Development Bank is a major player in the water and sanitation sector, a financier, consultant and project sponsor.
Background of the selected site
Demography of Mbhashe
- Population of Mbhashe Municipality by group, gender, and age
- Mbhashe household by population group
Compared to other regions, the Mbhashe Local Municipality represents 31.6% of the Amatole District Municipality population in 2021 (Table 4.2). In 2016, the female population in the age group 20-34 accounted for approximately 12.2% of the total female population, while the male population accounted for nearly 12.0% of the entire male population. The total population is defined as the total number of inhabitants quantified in a given area in the middle of the year.
This differs from the general situation in Amatole District, where the female population is 451,000, representing 52.35% of the total population of 862,000. The average annual growth rate of the total population is 0.05% and the average family size in Mbhashe municipality has decreased. The total Asian population is 0.2%, while the entire composition of the white population makes up 0.2% of all households.
Economic growth of Mbhashe Municipality
Between 2006 and 2016, the number of African-headed households increased by 0.84% per year, meaning households grew by 5,080. The average annual growth rate of families in all other population groups has increased by 0.84% (Municipality, 2016). In terms of total contribution to Amatole District Municipality, Mbhashe Municipality ranks third in the total GDP of Amatole District Municipality among all economies in the region.
The average annual GDP growth rates of Amatole District and Eastern Cape Province were 1.39% and 1.62%. South Africa is expected to grow at an average annual growth rate of 1.61%, which is higher than the local municipality of Mbhashe. With an average annual GDP growth rate of 1.23 between 2016 and 2021, Mbhashe ranked fourth compared to other regional economies (municipality, 2016).
Gross Value Added
- Primary Sector
- Secondary Sector
- Tertiary Sector
- Sector growth forecast
Between 2016 and 2006, the GDP of construction had the highest average annual growth rate in Mbhashe at 2.60%. The industry with the second highest average annual growth rate in the financial industry, with an average annual growth rate of 2.38%. On the other hand, mining has an average annual growth rate of 1.29%, while energy has the lowest average annual growth rate of 4.12%.
Manufacturing had the lowest growth rate in 2010, namely -11.0%, while construction reached the lowest point in 2010, namely with a growth rate of -5.1%. The social services sector, which mostly consists of the state, had the highest positive growth in 2008, i.e. 5.2%, and the lowest growth rate in 2013, i.e. 5.9%. The average annual growth rate of the primary industry from 2016 to 2021 is estimated to be 1.94%, while the average annual growth rate of the secondary industry is estimated to be 1.34%.
Water resources of Mbhashe Municipality
In the same period, the tertiary industry is expected to grow at an average annual rate of 1.16% (Municipality, 2016). Groundwater is widely used in more than 420 cities and many areas use groundwater as the only inflow for irrigation purposes. Groundwater is vital for the water supply of many cities in the driest part of South Africa (Lehohla, 2016).
Solar resources of Mbhashe Municipality
The highest temperatures occur in January, February, March and December, while the lowest temperatures occur in May, June and July.
Introduction
System description
Methodology of designing the reverse osmosis water treatment plant
- Determining water volume requirement
- Determining feedwater characteristics
- Estimating the maximum recovery ratio
- Calcium Salts
- Determining required membrane size
- Estimating the required total membrane area
- Estimating the required total membrane area
- Determining the required feed pressure
- Determining required pretreatment supply
- Estimating the required energy
- Supplementary energy requirements
- Considering brine water discharge
- Estimating the reverse osmosis capital cost
- Cost of desalination installation
- Cost of pretreatment installation
- Estimating the intake, outfall, and post-treatment cost
- Estimating the environmental assessment and contract costs
- Evaporation ponds costs
- Economic assessment of a reverse osmosis plant
- Capital repayment cost
- Specific cost of capital redemption
- Specific cost of energy
- Membrane replacements specific cost
- Cost of chemicals and consumable
- Labour and maintenance costs
- Total cost
Where 𝑅𝑅𝐶𝑎𝐹2 is the maximum allowed recycling ratio, and 𝐶𝐹 the Ca feed water concentration in milligrams per liter. Where 𝑅𝑅𝐹𝑒 is the maximum allowed recycling ratio and 𝐶𝐹𝑒 is the Fe feed water concentration in milligrams per liter. 𝑅𝑅𝑆𝑟𝑆𝑂4 is the maximum allowed recycling ratio, and 𝐶𝑆𝑟 is the feedwater concentration of Sr in milligrams per liter.
Where 𝑁𝑢𝑚𝑏𝑒𝑟𝐸𝑙𝑒𝑚𝑒𝑛𝑡𝑠 is the total required membrane components, 𝐴𝑟𝑒𝑎𝑇𝑜𝐴 is the total required membrane components in 𝑟𝑒𝑎𝑀𝑒𝑚𝑏𝑟𝑎𝑛𝑒 the membrane area of a component in square meters. Where 𝑆𝐶𝐶𝑎𝑝 is the specific cost of redemption in US $ per cubic meter, 𝐶𝑅 is the capital repayment cost, and 𝑄𝑇𝑜𝑡𝑎𝑙 is the total amount of water. 𝑆𝐶𝑀𝑎𝑖𝑛/𝐿𝑎𝑏𝑜𝑟 is the specific replacement cost of the membrane for a cubic meter of water in US $ per cubic meter, 𝑍 is the number of membranes, 𝐶𝑎 is the capital cost, 𝑎 𝑡𝑎𝑙 is the total amount of product water in cubic meters per day.
Design methodology of the renewable power system driving the RO
Optimization criteria
- Net Present Cost
- Cost of Energy (COE)
The optimal system setting is selected by considering levelized energy costs, net current costs, and reliable system configuration to select the best structure to meet the load demand. Net Present Cost (NPC) represents the sum of all costs involved over the life of the project. These costs include capital, operation and maintenance (O&M), replacement, and fuel costs, less damage, which is the expected value of the system at the end of the project's life.
Where 𝑖 and 𝑁 are respectively the annual interest and the year included in the calculation. Where 𝐸𝑠𝑒𝑟𝑣𝑒𝑑 is the primary load of the system and 𝐴𝐶𝑇 is the total cost of the component per years of the project's lifetime and expressed in equation (5.33) as (Kalinci et al., 2015):.
Technical reliability
- Inputs data
- Optimization methodology
Results and discussions
Reverse osmosis water treatment results
- Design product flow rate
- Total membrane area
- Feed-in pressure
- Design feed flow rate
- Plant specific energy demand
- Volume to be evaporated
- Cost of the plant
- Unit cost of water production
- Component costs
- Simulation constraint
- Technical optimization results
- Economic characteristics of the PV plant
- Summary of the result of the techno-economic feasibility of the solar-
The membrane specific flux (e) depends on the membrane manufacturer and can vary between 1 and 5 liters per m2.h.bar. This study is based on 4.5 litres/m2.h.bar. The yield characteristics of the reverse osmosis water treatment plant are shown in table 5.2. Thus, the total power requirement of the designed reverse osmosis water treatment plant is 249.9939 kW.
The price of the membrane generally depends on the manufacturer, the area of each element, the degree of rejection, the degree of pressure, etc. The energy production of the photovoltaic system is used to meet the energy needs of reverse osmosis, and the excess is used to charge the battery (Table 5.10). A summary of the technical-economic feasibility of a solar water purification system is shown in Table 5.11.
Conclusion
Moreover, the capital cost of the reverse osmosis water purification plant was approximately US while the capital cost of the photovoltaic plant is 2.6 million.
Recommendations for further studies
The Limpopo Watercourse Commission (LIMCOM) in Southern Africa is launching its first ever Groundwater Committee - GRIPP. https://gripp.iwmi.org the-limpopo-watercourse-commission-limcom- in-southern-africa-launches-its-first-ever-groundwater-committee/ 25 July 2021. Implementation of justice of the court. https://harvardlawreview.org/wp-content/uploads/pdfs/note.pdf. International research agency's perspectives on drinking water reuse. https://fac.ksu.edu.sa/sites/default/files/abcs_of_desalination.pdf.
Africa's most progressive water utility wins Stockholm Water Award for Industry 2014. https://www.prnewswire.com/news-. releases/most-progressive-water-utility-in-africa-wins-2014-stockholm-industry- water-award-260898711.html 8 December 2020. The State of Basic Service Delivery in South Africa: In-depth Community Analysis survey data 2016. Solar powered reverse osmosis water desalination system for rural village, AL Maleh: Design and simulation.
