Waste Water Management System - Term Paper Example

Title: Decentralized water Supply and Waste Water Management System Name: Registration No: Institution of Learning: Tutor: Date Due: TABLE OF CONTENTS 1.Introduction 3 2.Design for a decentralized water system 4 2.1.Pumping from the lake 4 Table 2. Standard concentrations of dissolved minerals per liter of water 5 2.2.Point of use design 5 3.Tank Design 6 4.Design for waste water management system 9 4.1.Waste water in the septic tank 9 4.2.Reed bed 11 5.Roles of various stakeholders in this project 13 6.Conclusion 15 7.References 15 LIST OF TABLES Table 1. Quality of pumped water before purification 4 Table 2. Standard concentrations of dissolved minerals per liter of water 5 Table 3. Composition of non-chemical impurities in the pumped water 5 Table 4. Quantities of dissolved minerals after treatment 8 Table 5. Composition of non-chemical impurities in the pumped water after treatment Sharma 9 Table 6. Quality of water that enters the septic tank and the standard concentrations for irrigation purposes 11 Table 7. Quality of water that leaves the reed bed 13 LIST OF FIGURES Figure 1. Schematic Representation of water treatment and storage before use 6 Figure 2. Tank Dimensions 7 Figure 3. The design of the chlorination point 8 Figure 4. Top View of the Septic Tank 10 Figure 5. Side View of the Septic Tank 10 Figure 6. Top View of the Reed Bed 12 1. Introduction This paper presents the design for a decentralized water supply system that is supplied to the residents from a lake. It involves supply of water to the central point where purification takes place after which it is distributed to residents. The design stages include extraction stage from the lake, point of use activities that include purification activities and finally discharge activities as waste water. In the waste water management design, the main areas of design include treatment of waste water and sludge management activities and finally the design for reed water management. When the residents’ have used the water, it becomes waste and discharged to waste water system where it is managed so that it does not contribute to harm to the residents. In addition, this paper provides a report of stakeholders whose contribution will be significant in achieving the goals of this study. 2. Design for a decentralized water system 2.1. Pumping from the lake Since the water will be derived from the lake, there are a number of impurities which will have an impact on its quality. The lake is used for a number of activities such as feeding livestock and washing domestic facilities, thus, there are animal droppings in the lake and dirt materials discharged from domestic activities. However, at the point of pumping, there will be a sieve which will facilitate prevention of entry of solids, stones and grasses from the lake from entering into the piping system. The piping system will lead to the point of treatment before water is discharged to the storage tank. The water will then be pumped using a pump that has a good operating point corresponding to the capacity of the tank so that the water is pumped at a reasonable velocity. In addition, it is expected that there will be a number of impurities that will have impact on its quantities. Based on studies that have been conducted on the constituents of the water from the lake, it has been found that there are a number of components which have considerable impacts on the quality of the water. These include manganese, calcium carbonates and other impurities. These are summarized in the table below. Component Percentage in milligrams per liter Calcium carbonates 500 Manganese 200 Sodium chloride 250 Iron compounds 100 TOTAL per 4 liters 1050 Table 1. Quality of pumped water before purification Sharma, S. K., & Sanghi, R. (2013). Wastewater reuse and management. Dordrecht: Springer. According to the above table, the percentage of dissolved minerals will account for 1050 milligrams per 4 liters of pumped water. This implies that the amount of dissolved solids is higher than the standard requirements for carbonates and other dissolved compounds in the pumped water. As a result, there will be the need for purification of the water before use. The following table provides the standard concentrations of the above minerals for a safe drinking water. Component Percentage in milligrams per liter Calcium carbonates 200 Manganese 100 Sodium chloride 150 Iron compounds 100 TOTAL per 4 liters 750 Table 2. Standard concentrations of dissolved minerals per liter of water Pumping will be done by selecting a pump that pumps water at 2.5 liters per second or 9000 liters per hour. This implies that the storage tank will be full after pumping for 62 hours or 2 ½ days. There are also a number of contaminants that will be present in the pumped water from the lake. The percentage compositions of these contaminants are summarized in the table below. Contaminant Percentage of 1 liter of water Standard Percentage of 1 liter of water Rotten leaves 1.7 1.0 Mud 2.5 1.2 Silt 1.6 0.9 Clay 1.3 0.8 Sand 1.2 0.5 TOTAL 8.4 4.4% Table 3. Composition of non-chemical impurities in the pumped water Letema, S. C. (2012). Assessing sanitary mixtures in East African cities. Wageningen: Wageningen Academic Publ. According to the figure above, the pumped water will be composed of 8.4% non-chemical impurities. This is higher than the standard requirements for percentage non-chemical contaminants in drinking water which is 4.4%. This result into the need for purification of the water by decreasing the concentrations of these substances before the water is pumped to residential areas for use. Consequently, the deign of the supply system will account for the process where these substances are removed. 2.2. Point of use design The design of the tank will be one that can be used for a period of 1 week by a population composed of 50 households where it will be expected that the total number of people in a single house will be 8. The daily consumption of water per person is expected to be 200L/day. Thus the capacity of the tank that will meet the requirements of the population for 1 week before another pumping operation is done is obtained by the product of 50*8*200*7= 560000 Liters. This implies that the population will be expected to consume 560000 liters in a week; hence the tank will be designed to this capacity. Based on the figures above, the tank will be designed for use by 400 people per day. This implies that daily water consumption will be 400*200= 80000 liters per day. Figure 1. Schematic Representation of water treatment and storage before use Lazarova, V., Choo, K.-H., & Cornel, P. (2012). Water-energy interactions of water reuse. London: IWA publ. 3. Tank Design The tank will be made of concrete wall and it will be circular in cross-section. The diameter of the tank will be 2 meters and its height will be 4 meters. The tank will be supported by a concrete base. At the bottom of the tank, there will be a, inlet pipe from the chlorination point while at the other end of the tank will be the outlet to residential areas. Figure 2. Tank Dimensions Larsen,tove A.., Udert, Kai M.., & Lienert, Judit. (2012). Wastewater Treatment: Source Separation and Decentralisation. Intl Water Assn. In order to ensure the pumped water is safe for drinking. It will be subjected to a number of treatment processes before it reaches the storage tank. The main treatment processes will involve: hardness removal stage and chlorination process, after which the water will be moved to the storage tank for storage and distribution to users. These processes are represented in Figure 1. In the hardness removal stage of water treatment process, soda ash will be added to the point where the water enters the chlorination point. This will ensure all dissolved salts such as sodium salts and carbonates are absorbed by the soda ash or absorbed to a considerable amount that their composition of the water is negligible. It will also ensure mud and sediments are precipitated from the water. From the hardness removal point, the water will be moved to chlorination point. The design of the chlorination chamber is as shown in the figure below. Figure 3. The design of the chlorination point Henze, M., & Ujang, Z. (2004). Municipal wastewater management in developing countries: Principles and engineering. London: IWA Publishing. The water will enter into the chlorinator where 3 HTH chlorine is added. This will ensure any bacteria and other harmful chemicals are destroyed. From this point, the water will be channeled to the storage tank for use. It is expected that there will be a considerable reduction in the chemical composition of the water stored in the tank. This is illustrated by the figure below. Component Percentage in grams per liter Calcium carbonates 100 Manganese 50 Sodium chloride 70 Iron compounds 80 TOTAL grams per 4 liters 300 Table 4. Quantities of dissolved minerals after treatment Al, B. I., Otterpohl, R., & Wendland, C. (2008). Efficient management of wastewater: Its treatment and reuse in water-scarce countries. Berlin: Springer. It will be found that there is a reduction in concentration of minerals win the purified water will be lower than the concentration before pumping. When the above compositions are compared with the standard requirements for safe drinking water, it is found that the values are lower than the standard values. This implies that the water will be safe for drinking and will not contribute to any impacts on users. Contaminant Percentage of 1 liter of water Rotten leaves 0.5 Mud 0.6 Silt 0.4 Clay 0.3 Sand 0.06 TOTAL 1.86% Table 5. Composition of non-chemical impurities in the pumped water after treatment Sharma, S. K., & Sanghi, R. (2013). Wastewater reuse and management. Dordrecht: Springer. When the above values are compared with the standard requirements for non-chemical composition of water for domestic use, it is found that it is lower than the standard concentration of 4.4% concentration with a concentration of 1.86%. This implies that it is safe for domestic use. 4. Design for waste water management system 4.1. Waste water in the septic tank When the water has been used, it will be drained into the septic tank. This will ensure wastes from domestic use are deposited into the tank and solid complements settle at the bottom of the tank. Due to anaerobic bacteria reactions, it will be possible to convert sewage into liquid and gases. This will result into a reduction of the volume of waste water to an appreciable level. In order to ensure the septic tank has the right capacity to contain the wastes, it will be constructed with a width of 0.75m and depth of 1m below the ground level. The length of each tank will be 2.8 meters and every septic tank will be provided with ventilation of about 50 mm diameter. A total of 4 septic tanks will be constructed to meet the wastes capacity from domestic applications. The inner sections of each septic tank will be plastered with cement and maintenance activity of the septic tank will involve cleaning the sludge every month. There will be a drainage system that connects the septic tank to the reed bed where the waste water from the septic tank will be discharged. Figure 4. Top View of the Septic Tank Larsen,tove A.., Udert, Kai M.., & Lienert, Judit. (2012). Wastewater Treatment: Source Separation and Decentralisation. Intl Water Assn. Figure 5. Side View of the Septic Tank Larsen,tove A.., Udert, Kai M.., & Lienert, Judit. (2012). Wastewater Treatment: Source Separation and Decentralisation. Intl Water Assn. When the water enters the septic tank, it is expected that it will be composed of a number of waste materials in various compositions. These are summarized in the table below. Contaminant Percentage of 1 liter of water Standard Percentage of 1 liter of water Solid wastes 10.2 5.4 Detergents 0.4 0.3 Sand 1.3 0.8 Dissolved oil 2.3 1.3 Kitchen fats 1.5 1.0 TOTAL 25.7 10.8 Table 6. Quality of water that enters the septic tank and the standard concentrations for irrigation purposes Letema, S. C. (2012). Assessing sanitary mixtures in East African cities. Wageningen: Wageningen Academic Publ. According to Table 6, the waste materials will account for 25.7% of waste matter from domestic activities while the standard concentration is 10.8% for irrigation purposes. This implies that the water in the septic tank will not be suitable for use in irrigation until it is subjected to recycling process. The recycling process will start at the septic tank where solid components will settle at the bottom of the tank while fats and oils will float on top of the waste water. An inspection port with a diameter of 10 cm will be constructed to enable stirring of the contents of the septic tank. When solid wastes have settled at the bottom of the septic tank, the liquid matter will be channeled to the reed bed section. 4.2. Reed bed The reed bed section will be a large area in the field where reeds have been grown. The water from the septic tank will flow by gravity into this section where it will come into contact with macrophytes. These plants will ensure most of the suspended solid materials are absorbed so that the water becomes cleaners and purer compared with the water in the septic tank. The dimensions of the reed bed will be 50 meters long 10 meters wide. The depth of the reed bed will be 0.5 m and it will be composed of three layers. The bottom layer will be where solid components from the septic tank will settle. The middle section will be the sludge level and the top section will be the water level. Various components of the reed bed will be included. These include detritus, substrates, worms, microorganisms and plants. Figure 6. Top View of the Reed Bed Letema, S. C. (2012). Assessing sanitary mixtures in East African cities. Wageningen: Wageningen Academic Publ. Figure 7. Cross sectional View of the Reed Bed Lazarova, V., Choo, K.-H., & Cornel, P. (2012). Water-energy interactions of water reuse. London: IWA publ. These components will contribute towards decomposition of the solid matter into less harmful forms so that the resulting water does not contain harmful organisms (Al, Otterpohl & Wendland, 2008). It will be expected that the reed bed will contribute to removal of the total suspended solids (TSS) by 99% and other physical processes that will take place in the reed bed is the sedimentation process through the filtration of the micro zone substrates and filtration of particles through adhesion to both wetlands and substrate and other films. As a result of TSS, it will be possible to remove organic matter, nutrients and pathogens. This process will be rapid and will be expected to take place within the first meter of the river bed (Henze & Ujang, 2004). When the water leaves the reed bed, it will be expected that there will be reduction in the quantities of wastes in it as shown in the table below. Contaminant Percentage of 1 liter of water Standard Percentage of 1 liter of water Solid wastes 1.2 5.4 Detergents 0.1 0.3 Sand 0.3 0.8 Dissolved oil 0.4 1.3 Kitchen fats 0.5 1.0 TOTAL 2.5 10.8 Table 7. Quality of water that leaves the reed bed Larsen,tove A.., Udert, Kai M.., & Lienert, Judit. (2012). Wastewater Treatment: Source Separation and Decentralisation. Intl Water Assn. The composition of contaminant after recycling will be made up of 2.5% contaminants. This is lower compared with the standard concentration of contaminants for safe water for irrigation which is 10.8%. As a result of the water having fewer compositions of waste materials, it will be suitable for other activities such as irrigation. The water from the reed bed will be considered suitable for irrigation and will be channeled to irrigation systems such as drip irrigation or overhead irrigation. It will also be suitable for industrial activities such as cleaning of machine components and processing of raw materials into finished products. 5. Roles of various stakeholders in this project There are a number of stakeholders who will be involved in the design of this water distribution and waste water management system. For instance, the Government authorities will ensure the contractor observes the guidelines required for the supply of clean and safe water for drinking. They will assess the safety of the pumped water fro drinking through testing of its chemical composition and purity from germs so that the use of the water is approved by the laws of the country (Lazarova, Choo & Cornel, 2012). They will ensure the water pumped from the lake is not high enough to cause drainage of the lake and also ensure the water discharged from residential areas do not cause pollution of the lake. The regulators will also be responsible for testing and commissioning of the piping system and water storage and distribution system to ensure it is functioning effectively before being authorized for use by the residential. Researchers will also conduct a number of research activities such as the right pump that will deliver enough water to the storage tank for storage of enough water for use. They will also conduct research on the piping and tank characteristics which are suitable for storage and distribution of water for domestic use (Larsen,tove, Udert, Kai & Lienert, 2012). In addition, they will conduct research on the lake to determine the capability of the lake to maintain its water capacity when water is pumped from it. The researchers will also conduct research on the functional components of the reed bed such as the role of micro-organisms in decomposing chemical components in the nitrification process so that the right microorganisms are introduced into the reed bed. In addition, they will determine the chemical composition of the water from the lake so that they can establish impurities that need to be removed. This will be followed by recommending the types of chemicals to be used n treatment of the water so that it is safe for domestic use. Other stakeholders will be householders who will be involved in the consumption of the pumped water. They will be responsible for proper use of the water and not causing damages to the piping systems and the tanks (Letema, 2012). They will also ensure they do not discharge used water to the environment so that it contributes to pollution. They will also ensure the water is treated well and safe before being used for domestic purposes. Other stakeholders will be plumbers whose function will be fitting the piping systems to the tank and the pump and also connecting the hardness removal point to the chlorination point so that the water undergoes the stages of design which contributes to effective treatment before use (Sharma & Sanghi, 2013). They will also be involved in maintenance of the piping systems to ensure any improper functioning and breakage is corrected. Other stakeholders who will be involved are system designers and consultants. They will come up with the manner in which the piping systems need to be laid on the ground and the pump design to be used in pumping the water (Henze & Ujang, 2004. They will also determine the physical and chemical properties of pipes and tank that need to be used to facilitate the pumping process. Any changes in the nature of the design for the water supply system will be communicated to them so that their approval can be obtained. They will coordinate with regulators to ensure the designs accounts for the demands of the regulating body with regards to construction of water supply and waste management system. 6. Conclusion In this study, reed beds will contribute significantly towards removal of sediments from the water so that it is safe for other purposes such as irrigation. In addition, this project provides a design of a system aimed at using the current technology of water recycling by ensuring domestic waste water can be safe for other purposes such as irrigation after being used. In addition, it applies the modern method of water treatment that allows large scale use by a large number of households through the implementation of chlorination method. The attainment of this project will also be facilitate by changes in land application activities where land can be set aside for reed beds which contribute significantly towards reduction of sediments in the water from domestic use into safe water for irrigation. The success of this project will also depend in exchange of information between stakeholder groups involved in the design and construction of the water supply system. This will involve the willingness of each stakeholder to contribute towards the achievement of the overall goal of designing and making operational the domestic water system and waste water management system. This report also acts as a guide to installers and plumbers so that they are familiar with the technology required to install and implement water supply system and waste water management systems so that they conform to the standards required during the process of installation of these systems. As a result, they will remember the important areas of the project so that success is achieved in implementation of the water supply and waste water management systems. As a result of the design and construction of the water supply and waste water management system for the residents, it will be possible to overcome a number of problems associated with the use of untreated water from the lake. This will result into reduced water-borne diseases thus ensuring the residents have better living standards. 7. References Al, B. I., Otterpohl, R., & Wendland, C. (2008). Efficient management of wastewater: Its treatment and reuse in water-scarce countries. Berlin: Springer. Henze, M., & Ujang, Z. (2004). Municipal wastewater management in developing countries: Principles and engineering. London: IWA Publishing. Larsen,tove A.., Udert, Kai M.., & Lienert, Judit. (2012). Wastewater Treatment: Source Separation and Decentralisation. Intl Water Assn. Lazarova, V., Choo, K.-H., & Cornel, P. (2012). Water-energy interactions of water reuse. London: IWA publ. Letema, S. C. (2012). Assessing sanitary mixtures in East African cities. Wageningen: Wageningen Academic Publ. Sharma, S. K., & Sanghi, R. (2013). Wastewater reuse and management. Dordrecht: Springer. Read More