Human generated water and wastewater cycles start by taking water from the natural hydrological cycle. It is distributed through the different human demand categories (industrial, residential, agricultural, ext) After use it enters the sewer system as wastewater and needs to be treated(as discussed in above pages) before it gets dispersed as effluent back to nature. The amount of water to satisfy the human demand and the amount of waste water discharged does not change that mutch. Give or take leakage or seapage in the water and wastewater system. This will always tie back into the natural hydrological cycle and principles thereof.
BOD is then determined by subtracting the second meter reading from the first . A TABLE DEMONSTRATING BOD LEVEL FOR DIFFERENT SAMPLES OF WATER CHEMICAL OXYGEN DEMAND It refers to the chemical decomposition of organic matter and the oxidation of inorganic chemicals. COD is used to measure the capacity of water to utilize oxygen during the decomposition of organic and inorganic contaminants. COD measurements are commonly made on samples of waste waters or of natural waters contaminated by domestic or industrial wastes. If COD reading of water is high; it means more pollutants are present in water.
Baths, showers, washing up, washing cloas and toilet flushing all use large amounts of water. Ase activities transform clean tap water into dirty wastewater. A water utility not only supplies clean drinking water but also collects, transports and dwasposes of a dirty water after it has been used. Sewerage Dirty water or sewage was collected firstly in drains and an in underground sewers and was transported via a sewerage system (a network of pipes and tunnels) to a sewage treatment works. Sewage Treatment Works Ase works use natural micro-organwasms to remove harmful substances from dirty water.
11. Total Solids in Water and Waste Water Introduction: The term “Total solids” includes all the solid constituents of a wastewater, which are as follows: • Organic Solids: This fraction is generally composed of dead animal matter and plant tissue. It may also include synthetic organic compounds. These compounds are subject to decay or decomposition through the activity of bacteria and other living organisms and are combustible. • Inorganic Solids: It includes sand, silt as well as the mineral salts in the water supply which produce the hardness and mineral content of the water.
The environmental problems such as eutrophication, eutrophication can be taken place when discharge excess both nitrogen and phosphorus into lakes or water bodies. The eutrophication is the lack of dissolved oxygen in water due to aquatic plants (e.g. algae) grow rapidly. Removal of residual suspended solids by granular-medium filtration Filtration system (including staining, an interception with media, gravity settling, internal impaction, and growth of bio-solid within the filter bed) uses to remove residual suspended solids (SS) by flowing water pass through the column medium. The type of filter affected directly to the SS
(CPHEEO, 2000) The dumped solid wastes receive water which moves through the waste deposition and the by-products of decomposition move into it. Thus, the liquid containing innumerable organic and inorganic compounds is called 'leachate'. (Nagarajan et al, 2012) Hence, leachate
Ground water is enormously varied in chemical composition and the factors controlling the composition includes physical, chemical and biological processes. Hutchinson (1957) defined fresh water as “dilute solutions of alkali and alkaline earth bicarbonate and carbonate, sulfate and chloride with available quantity of largely un-dissociated silicic acid which often is present in excess of sulfate and chloride”. There are also a number of minor elements in true solution, some of them being of great biological interest and a variety of colloidal materials, both inorganic and organic. Quantitative measurements of these parameters in natural water serve as source to address the basic environmental problems. Adopting suitable analytical methods
5, 6 indicated contour and surface plot based on the experimental design at 8.5 L/min air flow. The contour and surface figures were applied to specify the optimum level of each variable for the most response . It has been found that the optimal temperature for treatment and regeneration of spent caustic is 85 to 95 ºC. As well as is obvious from Fig. 5 which the process efficiency will be reduced after the present temperature.
Additionally, almost all of the industries in Addis Ababa do not have any waste management place and drain their wastes to the adjoining river areas. The water supply distribution of Addis Ababa has enormous leakage problem. This may show the way to mixing of water that comes from reservoirs and wells with the sewerage system in the
Conductivity is also used as an indicator to detect the amount of heavy metal ions present released from pollutants. Like conductivity, water density is also an indicator for presence of chemicals. Water density is related to salt content and water temperature and is used as an indicator for presence of organisms (Fundamentals of Environmental Measurements,