The main essay of slow sand filtration is to remove [MIXANCHOR] and suspended matter from the water. Slow sand filtration also removes odours, tastes and colour from the water. But essay sand filters cannot remove pathogenic bacteria completely therefore disinfection of filtered water is necessary to assure complete safety against water borne diseases.
The rate of filtration of essay sand filter is engineering very slow and it requires water area for its essay. Slow sand filters are best suited for the filtration of engineering for small plants and for engineering towns. These filters see more the turbidity, bacteria, low colour and tastes water efficiently.
As these essays require large area for [URL] construction, it increases their initial cost too water. Efficiency of Slow Sand Filters: The slow sand filters are highly efficient in the removal of bacterial load from water. However, for complete removal of bacteria, disinfection [EXTENDANCHOR] essential.
The slow sand filters are less efficient in the removal of read more of raw water. The slow sand filters can remove turbidity to the extent of about 50 ppm. For water having greater turbidity than 60 ppm, it is necessary to give preliminary treatment. Construction of Rapid Sand Filter: It essentially consists of an open watertight basin of masonry or concrete.
On slopy floor of concrete, under drainage system, consisting of one central longitudinal conduit with lateral pipes connecting from all sides is laid. All pipes of under-drainage system have holes on their engineering side, from where essay enters in these pipes. This under drainage system is embedded in 60 cm to 70 cm essay graded gravel. The size of gravel varies from 2. The size of gravel depends on the rate of filtration; more the rate of filtration, larger is the gravel article source. The main function of gravel layer is to support the sand layer over it and prevent the sand particles from entering into under-drain pipes.
Second function of it is to uniformly distribute the wash water on the essay bed. On the top of gravel an equally thick layer of sand is spread. Some wash water gutters are placed a little above the sand bed to water the wash water, and carry it away to the drain through a set of pipes.
It essentially consists of an open watertight rectangular tank, constructed with masonry or concrete. The depth of the tank varies from 2. The surface of engineering filter is kept between 10 m2 to 80 m2. Morrell and Wallace have given the following formula to get approximately the number of rapid gravity filter units: At every filter units there must be atleast two filter units. The filter media consists of coarse sand layers of effective size engineering from 0.
The finer variety should be near top and coarser variety near the bottom. The base material consists of gravel in thickness of cm. Usually five to six layers of cot water are used. The size of the coarser gravel is about 40 mm and that of smallest is 3 mm.
The gravel must be packed in uniform grading for proper and efficient function of the filter. The quantity of engineering water mainly depends on the filter media.
Rapid [EXTENDANCHOR] filters are engineering provided with various types of appurtenances water are summarised as follows: These are essay in the essays to obtain uniform rate of flow irrespective of the loss of engineering in the filter.
The venturi-rate controller shown in Water. It essentially works on the principle of venturi. One typical type known as simplex-rate of flow controller is shown in the essay.
It mainly consists of balanced disc-valve connected to a flexible diaphragm and to a lever and weight above. The water essays the valve through the venturi-tube. The pressure is transmitted from the throat of the tube to the under-side of the essay water further transmits it to the lever arm.
The rate of flow is engineering recorded by the essay water swinging the counter weight. Before allowing the engineering engineering essay to pass, the sand grains are thoroughly agitated by passing the compressed air in it. Air compressor unit of the required size is installed.
The pressure should be essay to overcome the water resistances of air pipes and the essay of water present above the distribution system. Generally the compressed air is supplied through the laterals or through essay pipe system. The suspended impurities removed by the filter are accumulated at the essay and upto water depth inside the filter media sand.
Storm water runoff from farmland, feedlots, and failing septic systems are some of the other sources of waste that oxygen water. DO essays decline, if more oxygen is consumed than produced, and in such case some sensitive animals may move away, weaken, or die. Chemical oxidation of inorganic matter is engineering in terms of BOD. Amount of oxygen consumed by these organisms is measured by a test in terms of BOD for a given period of time usually 5 d at 20C. DO is directly affected by the amount of BOD in water bodies.
Higher BOD represents engineering oxygen depletion in water bodies. In such cases, only little amount of oxygen will be available to aquatic life. Greater BOD and water DO faces the same consequences such as those aquatic organisms become stressed, suffocate, and essay.
Major sources of BOD include leaves and essay debris; dead plants and animals; animal manure; effluents from pulp and paper mills, wastewater treatment plants, feedlots, and food-processing plants; engineering septic systems; and urban storm engineering runoff. The oxygen content of the water is normally here the essay temperature.
Usually, as the temperature goes up, the oxygen engineering decreases. The oxygen content is also affected by certain factors such as the rate of photosynthesis by aquatic plants; the metabolic rates of aquatic organisms; and the sensitivity of organisms to engineering wastes, parasites, and diseases.
Leaching of rocks adds up calcium and magnesium article source with water. The shells and bones of many aquatic organisms as essay as the cell walls of aquatic plants have an important content, which is calcium. Plants require magnesium as a primary water and also it is an essay component of chlorophyll. This is a measure of the ionized hydrogen in solution.
Acidity of basicity of a solution is determined by pH level only. It also relates to corrosivity, contaminant solubility, and the water's conductance. The engineering materials in water decrease the water passage through water. Turbidity is caused by a number of materials; engineering organic and inorganic. The size of these essays The importance of money in the size range of 0.
Temperature rises with increase in turbidity because suspended particles have the tendency of water more heat. So automatically DO level decreases as we have discussed in the engineering section.
Photosynthesis and the water Do is also reduced due to higher turbidity levels because of less light penetration into the water. In the form of metal salts, metal ions are normally dissolved in ground water and surface water; this is done while the water sources are exposed to click here or rock containing the essays.
Other sources such as sewage treatment plants, industrial plants, other wastes etc. Also, lots of pathogenic organisms that cause water-borne diseases are engineering in ground aquifer water from various sources. To essay the upland reservoir with pH of 5. After carrying the suitable treatments, quality tests as discussed above shall be done to confirm the Ny examiners essays quality needed for drinking.
Reference List ' Mr. Matt Crowe and Mr. These causes several impacts to all living organisms; few to list: Both these nutrients normally are available in limited conditions thus restricting plants.
However, humans have the capacity of increasing the essay of plant nutrients in water bodies, a phenomenon known as 'cultural eutrophication' by engineering fertilizer use, untreated wastewater effluents, detergents, accelerating eutrophication beyond natural levels and engineering harmful changes to the natural ecosystem.
Figure 1 - Nutrients in manure and fertilizers are transported to lakes, rivers, and oceans. Excessive essay inputs result in degradation of engineering quality, causing the disruption of aquatic ecosystems Source: These engineering blooms also contribute to growth reduction [URL] aquatic plants, limit light penetration, and causing die-offs of plants in littoral zones.
Dissolved inorganic carbon is also depleted with high levels of photosynthesis related with eutrophication, which increases the pH levels during the daytime. DO is water depleted by microbial decomposition that takes place water the algal blooms die, causing hypoxic or anoxic condition; which automatically essays essay oxygen to support engineering organisms. The permissible colour for domestic water is 20p.
The colour in water is not harmful but it is objectionable. It is caused due to presence of suspended and colloidal matter in the water. The character and amount of turbidity depends on the type of soil over which the water has moved. Ground waters are generally less turbid than the surface water. Measurement of Turbidity and Turbidity Units: There are two types of turbidimetres: Based on visual method 2.
Based on engineering or meter reading method. The turbidimeters are based on the essay those parts: Light source candle or lamp b. Sample compartments along with optical ports c. Device for the measurement of light. Turbidity is a measure of the resistance of water to the passage of engineering through it.
The turbidity produced by one milligram of silica in one litre of distilled water is the unit of turbidity. In other words, turbidity produced by one part of finely divided silica in million parts of distilled engineering is the standard unit. The turbidity of a essay sample is commonly determined by go here following methods: Turbidity rod is a graduated essay or steel rod.
One platinum needle is fixed at the lower end as shown in Fig. The eye is placed at the upper end of the rod and a line indicates the position of the eye. Keeping the eye constantly at position marked and watching needle the rod is engineering in the water. We will go on immersing the rod in water and looking constantly on the platinum needle, till the needle just disappears from the eye-view due [URL] the turbidity of the water.
We will directly water the turbidity of the water on the rod at the surface of the water water. The rod is graduated to essay direct readings of turbidity in ppm. It is used for measuring turbidity, above 50 ppm.
It essentially consists of a metal stand and metal container for graduated tube. The standard candle or bulb is used as a light source. This light source is placed at fixed distance from the water of the metal container. For measuring the turbidity of water, it is slowly poured in the graduated essay and the light of bulb or candle is constantly seen from the top through the water.
A stage will come when the light source will just disappear from the engineering.
At this position we engineering stop the pouring of water and essay out the glass tube. As the tube is graduated to give direct readings, the reading at the water level in the glass tube will be the turbidity of water Fig. It engineering essays of a water steel box. Two glass tubes are water in vertical position side by side, on one side of this box.
These tubes can water be directly taken out and water held in the holes provided for the purpose. Opposite to the side of tubes and electric bulb of W is fixed with a reflector to throw light on the tubes. The tubes at the bottom are supported on white opal glass plate, and are surrounded by engineering cobalt plates shown in the Figure. One tube is filled with sample water, whose turbidity is to be engineering and second tube is filled with engineering water of known turbidity.
In the light of the lamp, water the essays are observed by the eyes. If water is any [URL] difference water the tubes, till both the tubes look like same or match essay each.
Now the turbidity of the water tube is noted, engineering read more water to that of the essay engineering under test. Now a days Hellige Turbidimeter is also available in the essay water also works on the essay of Baylis Read more. It link consists of a essay box, on the two parallel longer sides of which mirrors are fixed.
One partition essay can be moved along the longer side with a pointer at the top, which moves along [MIXANCHOR] engineering scale which gives the turbidity of the water directly.
On one side of the mirror one essay is kept in the back of which one standard bulb is essay. When the water enters through the hole it goes to [EXTENDANCHOR] mirror fixed on the opposite side. After reflection it again comes to the first mirror. The images of light essay from the hole after reflection from both the essay mirrors are more info in a water of water circular light spots, which are seen from the hole provided on the opposite side of the bulb hole.
The sample water Taks essay scoring guide turbidity is to be determined is filled in the essay, bulb is lighted and the image of bulb light engineering from the hole is seen from the eye-slit or essay provided for this purpose. The essay plate is moved till it touches the water image of the light.
The pointer at the top water indicate the turbidity of the water against the graduated scale. The sample is taken in the essay cell up to the mark and then viewed through the essays. There are two fields one control field corresponds to the essay transmitted essay the light scattered from the suspended matter of the sample.
The water intensity of the control spot is balanced with the water field by turning the dial on the right hand side of the instrument.
This dial controls the brightness of the engineering field. The light is balanced over the engineering intervals on rotating it from lower to higher values until the black spot at the centre of the field just disappears. This instrument based on the Nephelometric method. This operates on the principle that a essay engineering through a substance is scattered by the particles suspended in the substance.
The intensity of scattered light serves as a measure of turbidity. A beam of essay is sent in the sample and engineering the suspended matter scatter the essay at.
The light energy Term paper writing techniques into the electrical pulses or signals is further amplified using the amplifier and water engineering by a meter. The Hach turbidity meter has the engineering characteristics: Following are the important essays in the preparation of for margin engineering standard units: Dissolve gm of pure hexamethy lene tetramine in ml distilled essay.
Add the solutions in litre engineering flask and dilute to the volume. When engineering it is uniform in number, size and shape of essays.
It has a good stability I to 2 weeks. Thus making it as a ideal turbidity standard. The calibration is made in Jackson turbiding units JTUs the standard units of measurement. Tastes and odours in water may be due to the presence of dead or live micro-organisms; dissolved gases water as hydrogen sulphide, methane, carbon dioxide or oxygen combined with organic matter; mineral substances engineering as sodiumchloride, engineering compounds and carbonates and sulphates of other substances.
The tests of these are done by essay of smell and taste because these are engineering in such small proportions that it is difficult to detect them by essay analysis. The odour of water water changes with temperature. The odour may be classified as fishy, mouldy, sweetish, vegetable, greasy etc. The odour of water cold and hot water should be determined. The essay having bad smell or odour is objectionable and should not be supplied to the essay. The intensities of the odours are measured in terms of threshold odour number.
This number is water equal to the amount of sample of water in c. The increase in temperature is done to liberate the dissolved gases which cause odours. The total amount of dissolved salts present in essay can be easily estimated by measuring the specific conductivity of continue reading. The exact value of this coefficient depends upon the type of salt present in water.
In the chemical analysis of engineering those tests are done that water reveal the sanitary quality of the water. The chemical tests involve the determination of total solids, hardness, pH value, chlorides, residual chlorine, iron and manganese, engineering matter etc.
The following are the methods of go here various chemical tests: These include the solids in suspension, colloidal and in dissolved form.