Wastewater System for Households, Concentrations of Pollutants in Wastewater, Specific Elements, and Effects - Coursework Example

Name: Course: Instructor: Date: Introduction Human activities in the houses result into production of wastewater pollutants. Human beings cannot avoid these activities for example washing of dishes, flushing of toilets, emptying of sinks. These activities produce different amounts pollutants. Amount of wastes produced depends on a person’s standard of living and lifestyle (Henze, 1997). Some of the contents of wastewater include nutrients, microorganisms, biodegradable organic materials, metals and thermal effect. Table 1: Contents of Household Wastewater Water waste pollutants Specific Elements Effects Nutrients Nitrogen, phosphorus, ammonia Toxic effect, depletion of oxygen and eutrophication Microorganisms Worms, virus and pathogenic bacteria Odours and risk faced during bathing Biodegradable organic materials Oxygen depletion in various water source Odour Other organic materials Grease, oil, fat, coloring, cyanide, solvents, detergents and phenols Aesthetic inconveniences, toxic effect and bio accumulation in food chain Metals Lead, mercury, nickel and copper Bioaccumulation and toxic effect Other inorganic materials Acids, such as hydrogen sulphide, and bases Toxic effect and corrosion Thermal effects Hot water Table 2: Daily water usage Daily water usage varies from household to household. Water usage and production of wastewater is influenced by various factors, such as, lifestyle and living standards of house occupants. Type of use Total Daily Usage (litres) Bath 100 Shower 80 Toilets 70 Kitchen 50 Laundry 70 Table 3: Concentrations of Pollutants in wastewater Wastewater contains various pollutants, which has different levels of concentration. Concentration of wastewater depends on the source of the wastewater for example, whether it is from kitchen, laundry, or toilet. Elements Unit Toilet Kitchen Laundry/bath Total Total Urine Wastewater L/month 16 10 18 18 55 Chemicals L/month 26.5 5.5 16 3.7 47.2 Biodegradable components kg/month 8.1 1.6 11 1.8 21.9 Nitrogen kg/month 4.3 3.8 0.3 0.4 5.1 Phosphorus kg/month 0.7 0.5 0.007 0.1 0.87 Copper kg/month 1.3 0.9 0.15 0.15 1.6 Recycling Grey - Water Grey water refers to water from the households except water from the toilet that is referred to as black water. Grey water is not as harmful as black water. However, if it is stored for long it may become black water. Recycling grey water involves re-using of water produced from one activity to another for example using wastewater from the kitchen to flash toilets The quantity and quality of wastewater varies from one household to another. The variation depends on various factors such as economic conditions, psychological condition, and weather and climate changes (Henze, 1997). Due to the high amounts of organic materials present in wastewater, it is necessary to remove them in order to make the remaining part more degradable thus reducing pollution. The contents of the wastewater reduced or increased. Wastewater components can be reduced through; Reducing the level at which wastes are generated in a house Diverting solid wastes into the solid bins, in order to stop them from flowing with the liquid components wastewater To reduce phosphorus, nitrogen, and other organic load of wastewater one need to practice urine-toilet separation. Urine contributes a higher percentage of wastewater; therefore, its separation from the toilet will ensure reduction in nutrients loads in the wastewater. Analysis of the kitchen waste shows that it contents has a high amount of organic waste that forms wastewater in the household (Henze, 1997). Therefore, it would be more appropriate when the kitchen wastes are diverted to solid wastes by use of system known as “Cleantech” cooking. This would lead to reduction of the organic contents in the wastewater. “Cleantech” cooking is a system that involves putting food wastes into the bins instead of flashing them with water. As a result, the food waste that has been diverted can be thrown away with other organic waste substances from the kitchen. Wastes from kitchen also has chemicals which when used can affect the load and composition of the waste. Laundry and bath also produces wastewater that has minimal pollution load. The part of the minimal pollution in the wastewater from the bath and laundry is due to household chemicals (Henze, 1997). To recycle this wastewater, it can be used together with the kitchen wastewater to flush toilets. Part of the kitchen solid waste can be stored separately or combined with waste from the kitchen for disposal in the compost or undergo anaerobic treatment (Henze, 1997). Many households use grinders or disposal units to handle the disposable solid waste. However, this method has faced criticism since it increases waste loads in the sewer. In this method, disposal of wastes from the households through the sewer will not affect the waste load produced in the household, but it instead changes the transportation route for the wastewater pollutants. Wastewater System for Households Wastewater contains various pollutants that need proper management to ensure no further pollution. This requires appropriate system to remove some pollutants in the wastewater. The system ensures that wastewater remain with materials that are biodegradable and can easily decompose (Henze, 1997). In order to reduce pollution, recycling and “Cleantech “cooking are applied to ensure removal of solid and other organic materials in wastewater. Using of “cleantech” cooking and methods such as flushing toilets with wastewater from the kitchen can facilitate the development of wastewater system for managing wastewater pollutants from the households (Henze, 1992). To reduce pollutants load in the wastewater various actions need to take place. These actions include. Diversion of a portion of wastewater from the kitchen to the bin meant for solid waste. This involves separating solid components of the wastewater from the liquid part (Henze M.1992). This action involves reducing the weight of the waste load by separating toilet and “Cleantech” cooking (g/cap). Reducing the weight of the mass load in wastewater makes the wastewater less harmful hence enabling one to recycle it. COD and BOD The main contents of wastewater comprises of the organic substances. These organic substances are measured using COD and BOD (Henze, et., al. 1987). Analysis using COD is ‘quick and dirty’ especially when mercury is used in the process. Dilution process makes BOD analysis cumbersome and slow. COD process involves chemical oxidation of organic substances by use of dichromate. COD analysis is carried out to ensure there is load balance in treatment of wastewater (Henze, 1997). COD and BOD analysis involves measurements of solid particles in wastewater and to ensure all the necessary solid particles are eliminated during wastewater treatment. Table 4: Reduction of waste load to Wastewater by “Cleantech” cooking and separation of toilet (Henze, 1997) Technology Traditional Separation of toilet Cleantech coooking COD 130 55 32 BOD 60 35 20 Nitrogen 13 2 1.5 Phosphorus 2.5 0.5 0.4 This system enables households to save water and to ensure reduction in the weight load of the wastewater, COD and BOD analysis enables one to measure the amount of solid particles in wastewater, hence enabling determination of whether the wastewater can be recycled. Table 5: Concentration of wastewater after toilet separation and “Cleantech” Cooking (g/) (Henze, 1997) Production of Wastewater 250 1/cap.d 160 1/cap.d 80 1/cap.d COD 130 200 400 BOD 80 125 250 Resultant Nitrogen 6 9 19 Resultant Phosphorus 1.6 2.5 5 To produce the above reduction in load weight in wastewater it is assumed that the detergent is free of phosphates. Separation and “cleantech” cooking affects the composition of COD and BOD (Almeida, et. al, 2000). This leads to changes between suspended and soluble contents. The changes in the components of the wastewater after separation of the toilet and cleantech cooking affect the nature of the wastewater. It may lead to production of a portion of wastewater that is more degradable. As a result, the level of pollution as a result of wastewater is reduced since the remaining portion can easily decompose. Diversion of the organic wastes in the wastewater to the sewer may lead to the production of a less poisonous wastewater. Conclusion Household activities produce wastewater that its contents are not friendly when human beings are exposed to them. Some of these wastewater contents undergo treatment process to make it more useful. The main contents removed include the solid particles. The solid particles are removed in order to ensure the remaining wastewater is more degradable. This process involves production of grey water, a type of water free of toilet products. Production of grey requires recycling of wastewater in order to reduce the level of wastewater produced in households. In addition, diversion of solid particles into solid bin is important to ensure to ensure one produces wastewater free of solid particles. After diversion and separation of toilet, one is able to measure amount of solid particles in wastewater by use of BOD and COD analysis. This ensures one is able to recycle wastewater from for example kitchen and use it to flash toilets. In the process use of municipal, which consists of high percentage of water used in houses can be controlled and avoid its misuse. References Almeida M.C., et., al (2000) At source domes., tic wastewater quality. Urban Water Henze, et., al. (1987) Activated sludge model No.1. IAWPRC Scientific and Technical Reports No.1. IWA Publications, London. Henze M. (1992) Characterization of wastewater for modelling of activated sludge processes. Wat. Sci. Tech. 25(6), 1-15. Henze M. (1997) Waste design for households with respect to water, organics and nutrients. Wat. Sci. Tech. 35(9), 113–120. Read More