CHAPTER-I
Introduction ________________________________________
1.1. Introduction
Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids and gases from water. The goal is to produce water fit for a specific purpose. Most water is disinfected for human consumption (drinking water), but water purification may also be designed for a variety of other purposes, including fulfilling the requirements of medical, pharmacological, chemical and industrial applications. The methods used include physical processes such as filtration, sedimentation, and distillation; biological processes such as slow sand filters or biologically; chemical processes such as flocculation and chlorination and the use of electromagnetic radiation such as ultraviolet light. Purifying water may reduce the concentration of particulate matter including suspended particles, parasites, bacteria,algae, viruses, fungi, as well as reducing the concentration of a range of dissolved and particulate matter. The standards for drinking water quality are typically set by governments or by international standards. These standards usually include minimum and maximum concentrations of contaminants, depending on the intended purpose of water use. Visual inspection cannot determine if water is of appropriate quality. Simple procedures such as boiling or the use of a household activated carbon filter are not sufficient for treating all the possible contaminants that may be present in water from an unknown source. Even natural spring water ‘ considered safe for all practical purposes in the 19th century ‘ must now be tested before determining what kind of treatment, if any, is needed. Chemical and microbiological analysis, while expensive, are the only way to obtain the information necessary for deciding on the appropriate method of purification. According to a 2007 World Health Organization (WHO) report, 1.1 billion people lack access to an improved drinking water supply, 88% of the 4 billion annual cases of diarrheal disease are attributed to unsafe water and inadequate sanitation and hygiene, while 1.8 million people die from diarrheal disease each year. The WHO estimates that 94% of these diarrheal disease cases are preventable through modifications to the environment, including access to safe water. Simple techniques for treating water at home, such as chlorination, filters, and solar disinfection, and storing it in safe containers could save a huge number of lives each year reducing deaths from waterborne diseases is a major public health goal in developing countries.
1.2. Treatment
1.2.1. Goals
The goals of the treatment are to remove unwanted constituents in the water and to make it safe to drink or fit for a specific purpose in industry or medical applications. Widely varied techniques are available to remove contaminants like fine solids, micro-organisms and some dissolved inorganic and organic materials, or environmental persistent pharmaceutical pollutants. The choice of method will depend on the quality of the water being treated, the cost of the treatment process and the quality standards expected of the processed water.
The processes below are the ones commonly used in water purification plants. Some or most may not be used depending on the scale of the plant and quality of the raw (source) water.
1.2.2. Pretreatment
1. Pumping and containment ‘ The majority of water must be pumped from its source or directed into pipes or holding tanks. To avoid adding contaminants to the water, this physical infrastructure must be made from appropriate materials and constructed so that accidental contamination does not occur.
2. Screening (see also screen filter) ‘ The first step in purifying surface water is to remove large debris such as sticks, leaves, rubbish and other large particles which may interfere with subsequent purification steps. Most deep groundwater does not need screening before other purification steps.
3. Storage ‘ Water from rivers may also be stored in bankside reservoirs for periods between a few days and many months to allow natural biological purification to take place. This is especially important if treatment is by slow sand filters. Storage reservoirs also provide a buffer against short periods of drought or to allow water supply to be maintained during transitory pollution incidents in the source river.
4. Pre-chlorination ‘ In many plants the incoming water was chlorinated to minimize the growth of fouling organisms on the pipe-work and tanks. Because of the potential adverse quality effects (see chlorine below), this has largely been discontinued.
1.2.3. PH adjustment
Pure water has a PH close to 7 (neither alkaline nor acidic). Sea water can have PH values that range from 7.5 to 8.4 (moderately alkaline). Fresh water can have widely ranging PH values depending on the geology of the drainage basin or aquifer and the influence of contaminant inputs (acid rain). If the water is acidic (lower than 7), lime, soda ash, or sodium hydroxide can be added to raise the PH during water purification processes. Lime addition increases the calcium ion concentration, thus raising the water hardness. For highly acidic waters, forced draft degasifies can be an effective way to raise the pH, by stripping dissolved carbon dioxide from the water. Making the water alkaline helps coagulation and flocculation processes work effectively and also helps to minimize the risk of lead being dissolved from lead pipes and from lead solder in pipe fittings. Sufficient alkalinity also reduces the corrosiveness of water to iron pipes. Acid (carbonic acid, hydrochloric acid or sulphuric acid) may be added to alkaline waters in some circumstances to lower the PH. Alkaline water (above pH 7.0) does not necessarily mean that lead or copper from the plumbing system will not be dissolved into the water. The ability of water to precipitate calcium carbonate to protect metal surfaces and reduce the likelihood of toxic metals being dissolved in water is a function of PH, mineral content, temperature, alkalinity and calcium concentration.
1.3. Filtration
After separating most flock, the water is filtered as the final step to remove remaining suspended particles and unsettled flock.
1.3.1. Rapid sand filters
Cutaway view of a typical rapid sand filter
The most common type of filter is a rapid sand filter. Water moves vertically through sand which often has a layer of activated or anthracite coal above the sand. The top layer removes organic compounds, which contribute to taste and odour. The space between sand particles is larger than the smallest suspended particles, so simple filtration is not enough. Most particles pass through surface layers but are trapped in pore spaces or adhere to sand particles. Effective filtration extends into the depth of the filter. This property of the filter is key to its operation: if the top layer of sand were to block all the particles, the filter would quickly clog.
To clean the filter, water is passed quickly upward through the filter, opposite the normal direction (called back flushing or backwashing) to remove embedded or unwanted particles. Prior to this step, compressed air may be blown up through the bottom of the filter to break up the compacted filter media to aid the backwashing process; this is known as air scouring. This contaminated water can be disposed of, along with the sludge from the sedimentation basin, or it can be recycled by mixing with the raw water entering the plant although this is often considered poor practice since it re-introduces an elevated concentration of bacteria into the raw water.
Some water treatment plants employ pressure filters. This work on the same principle as rapid gravity filters, differing in that the filter medium is enclosed in a steel vessel and the water is forced through it under pressure.
Advantages:
‘ Filters out much smaller particles than paper and sand filters can.
‘ Filters out virtually all particles larger than their specified pore sizes.
‘ They are quite thin and so liquids flow through them fairly rapidly.
‘ They are reasonably strong and so can withstand pressure differences across them of typically 2’5 atmospheres.
‘ They can be cleaned (back flushed) and reused.
1.4. Membrane filtration
Membrane filters are widely used for filtering both drinking water and sewage. For drinking water, membrane filters can remove virtually all particles larger than 0.2 ”m’including giardia and cryptosporidium. Membrane filters are an effective form of tertiary treatment when it is desired to reuse the water for industry, for limited domestic purposes, or before discharging the water into a river that is used by towns further downstream. They are widely used in industry, particularly for beverage preparation (including bottled water). However no filtration can remove substances that are actually dissolved in the water such as phosphorus, nitrates and heavy metal ions.
1.5. Removal of ions and other dissolved substances
Ultrafiltration membranes use polymer membranes with chemically formed microscopic pores that can be used to filter out dissolved substances avoiding the use of coagulants. The type of membrane media determines how much pressure is needed to drive the water through and what sizes of micro-organisms can be filtered out. Ion exchange: Ion exchange systems use ion exchange resin- or zeolite-packed columns to replace unwanted ions. The most common case is water softening consisting of removal of Ca2+ and Mg2+ ions replacing them with benign (soap friendly) Na+ or K+ ions. Ion exchange resins are also used to remove toxic ions such as nitrite, lead, mercury, arsenic and many others. Precipitate softening Water rich in hardness (calcium and magnesium ions) is treated with lime (calcium oxide) and/or soda-ash (sodium carbonate) to precipitate calcium carbonate out of solution utilizing the common-ion effect. Electrode ionization: Water is passed between a positive electrode and a negative electrode. Ion exchange membranes allow only positive ions to migrate from the treated water toward the negative electrode and only negative ions toward the positive electrode. High purity deionized water is produced continuously, similar to ion exchange treatment. Complete removal of ions from water is possible if the right conditions are met. The water is normally pre-treated with a reverse osmosis unit to remove non-ionic organic contaminants, and with gas transfer membranes to remove carbon dioxide. A water recovery of 99% is possible if the concentrate stream is fed to the RO inlet.
1.6. Other Water Purification Techniques
Other popular methods for purifying water, especially for local private supplies are listed below. In some countries some of these methods are also used for large scale municipal supplies. Particularly important are distillation (de-salivation of seawater) and reverse osmosis.
1. Boiling: Bringing it to its boiling point at 100 ”C (212 ”F), is the oldest and most effective way since it eliminates most microbes causing intestine related diseases, but it cannot remove chemical toxins or impurities. For human health, complete sterilization of water is not required, since the heat resistant microbes are not intestine affecting. The traditional advice of boiling water for ten minutes is mainly for additional safety, since microbes start getting eliminated at temperatures greater than 60 ”C (140 ”F). Though the boiling point decreases with increasing altitude, it is not enough to affect the disinfecting process. In areas where the water is “hard” (that is, containing significant dissolved calcium salts), boiling decomposes the bicarbonate ions, resulting in partial precipitation as calcium carbonate. This is the “fur” that builds up on kettle elements, etc., in hard water areas. With the exception of calcium, boiling does not remove solutes of higher boiling point than water and in fact increases their concentration (due to some water being lost as vapour). Boiling does not leave a residual disinfectant in the water. Therefore, water that is boiled and then stored for any length of time may acquire new pathogens.
2. Granular Activated Carbon adsorption: a form of activated carbon with a high surface area, adsorbs many compounds including many toxic compounds. Water passing through activated carbon is commonly used in municipal regions with organic contamination, taste or odours. Many household water filters and fish tanks use activated carbon filters to further purify the water. Household filters for drinking water sometimes contain silver as metallic silver nanoparticle. If water is held in the carbon block for longer periods, microorganisms can grow inside which results in fouling and contamination. Silver nanoparticles are excellent anti-bacterial material and they can decompose toxic halo-organic compounds such as pesticides into non-toxic organic products.
3. Distillation involves boiling the water to produce water vapour. The vapour contacts a cool surface where it condenses as a liquid. Because the solutes are not normally vaporised, they remain in the boiling solution. Even distillation does not completely purify water, because of contaminants with similar boiling points and droplets of unvapourised liquid carried with the steam. However, 99.9% pure water can be obtained by distillation.
4. Reverse osmosis: Mechanical pressure is applied to an impure solution to force pure water through a semi-permeable membrane. Reverse osmosis is theoretically the most thorough method of large scale water purification available, although perfect semi-permeable membranes are difficult to create. Unless membranes are well-maintained, algae and other life forms can colonize the membranes.
5. Direct contact membrane distillation (DCMD). Applicable to desalination. Heated seawater is passed along the surface of a hydrophobic polymer membrane. Evaporated water passes from the hot side through pores in the membrane into a stream of cold pure water on the other side. The difference in vapour pressure between the hot and cold side helps to push water molecules through.
6. Desalination ‘ is a process by which saline water (generally sea water) is converted to fresh water. The most common desalination processes are distillation and reverse osmosis. Desalination is currently expensive compared to most alternative sources of water, and only a very small fraction of total human use is satisfied by desalination. It is only economically practical for high-valued uses (such as household and industrial uses) in arid areas.
7. In Situ Chemical Oxidation, a form of advanced oxidation processes and advanced oxidation technology, is an environmental remediation technique used for soil and/or groundwater remediation to reduce the concentrations of targeted environmental contaminants to acceptable levels. ISCO is accomplished by injecting or otherwise introducing strong chemical oxidizers directly into the contaminated medium (soil or groundwater) to destroy chemical contaminants in place. It can be used to remediate a variety of organic compounds, including some that are resistant to natural degradation.
8. Bioremediation is a technique that uses microorganisms in order to remove or extract certain waste products from a contaminated area. Since 1991 bioremediation has been a suggested tactic to remove impurities from water such as alkenes, per chlorates, and metals. The treatment of ground and surface water, through bioremediation, with respect to perchlorate and chloride compounds, has seen success as perchlorate compounds are highly soluble making it difficult to remove. Such success by use of Dechloromonas agitate strain CKB include field studies conducted in Maryland and the Southwest region of the United States. Although a bioremediation technique may be successful, implementation is not feasible as there is still much to be studied regarding rates and after effects of microbial activity as well as producing a large scale implementation method.
CHAPTER-II
Literature Review ________________________________________
2.1 Solar Water Purifier
Name of journal:- International Journal of Innovative Research in Advanced Engineering (IJIRAE) ISSN: 2349-2163 Volume 1 Issue 9 (October 2014)
Author: – Deepak Devasagayam , Mayuresh Kathe, Mayur Patil, Nimish Kavishwar
Abstract’ Carbon filters are very effective at removing chlorine, benzene, radon, solvents trihalomethane compounds, volatile organic chemicals such as pesticides and herbicides and hundreds of other man-made chemicals that may come into contact with tap water as it proceeds through the system. In addition, filters remove bad tastes and odours from the water. After this initial filtration by carbon filter, water is then passed to evacuated vacuum tubes for remaining purification. A parabolic trough is a type of solar thermal collector that is straight in one dimension (Z-axis) and curved as a parabola in the other two (X and Y-axis), lined with a polished mirror like finish metal. The energy of sunlight which enters the collector parallel to its plane of symmetry is focused along the focal line where the vacuum tube is placed. The vacuum that surrounds the outside of the tube greatly reduces convection and conduction heat loss, therefore achieving greater efficiency than flat-plate collectors.
Keywords’ Solar, Water Purifier, Thermal distillation, carbon filter, parabolic dish
2.2 Water Purification System For Remote Areas Using Photovoltaic
Name of journal: – International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue4, July-August 2012, pp.2014-2018
Author : – S.S.Phuse , R.S.Shelke
Abstract:-
Water purification is the process of removing undesirable chemicals ,biological contaminants ,suspended solids and gases from contaminated water .Propose water purification system for remote areas focus on providing a pure drinking water at low cost with high reliability to the rural families. It involves the research, design and manufacture of water purification system using renewable energy. It consist of a combination of solar pasteurization, reverse osmosis (RO) and ultraviolet (UV) lamp sterilizer system with power supplied by photovoltaic (PV) modules. It is an effective
Method to deactivate bacteria, viruses and protozoan in contaminated water .This method can be made portable, cost effective, user compliant and energy efficient enough to meet the drinking water needs .Experimentation is carried out for testing six different water samples. Water samples selected are tap water, well water, river water, lake water, muddy water and colour water. All the water samples are analyzed and tested in a laboratory for different parameters and found within the standard range .This paper will be helpful for those who are working in the area of water purification system and their use in remote areas.
Keywords: Reverse osmosis system, photovoltaic, solar pasteurization.
2.3 Thermal Modelling and Efficiency of Solar Water Distillation: A Review
Name of journal:- International Journal for Ignited Minds (IJIMIINDS)
Author: – Dr. Bhupendra Gupta ,Pankaj j Edla ,Tonish Kumar Mandraha, Mohit Pandya
Abstract: – The most important aspect for sustaining life on earth is water. In spite of its abundant availability, a small percentage can be used for drinking purpose (approximate 1%). The solar water distillation comes out to be a non toxic and promising device which purifies water that uses a renewable solar energy source, Efficiency of the solar water distillation device can be enhanced by increasing evaporation rate that is a combined effect of solar radiation, cover glass temperature, water contamination density, base plate absorptivity and provide additional heat by solar water preheating system. Various investigators uses thermal modelling technique to analyses performance of Solar water distillation device carrying above mentioned factors as basis and shows an optimum value to enhance efficiency. Present paper is a tabulated review of all these governing parameters and modeling equations available for suitable selection.
Keywords: – Solar water distillation, Solar Energy, Active and Passive techniques, Thermal modelling, Heat and mass transfer relation.
2.4 SOLAR AQUA PURIFIER AND ITS WATER QUALITY MANAGEMENT
Name of journal:- International Journal of Industrial Electronics and Electrical Engineering, ISSN: 2347-6982 Volume-3, Issue-5, May-2015
Author : – A. D.Zope, R.R.Deshmukh, D.R.Mete, V.S.Mane
Abstract- Municipal water treatment plants play a really significant part in the maintenance of community wellness. Applying standard computer vision based solutions have a positive impact on the operations, maintenance, process development and savings for the wastewater treatment plants (WWTP). The objective of this paper is to design a ‘Lab VIEW-PIC’ hardware and software application implemented on wastewater treatment plant to produce a comprehensive real-time management environment for a modern wastewater purification plant. The refinement of water is done by RO and UV process. The entire system is powered by solar panels to reduce the capital requirement. Parameters of the purified water such as pH, water level of the tank, temperature and the amount of power generated are measured and monitored to meet the required standards set by the WHO (World Health Organization). These parameters are displayed using a Graphical User Interface (GUI).
Keywords- GUI, Lab View, PIC, Water Treatment
2.5 Performance Analysis of Solar Water Purification by using Thermal Method
Name of journal: – International Journal on Recent and Innovation Trends in Computing and Communication ISSN: 2321-8169 Volume: 3 Issue: 8 5132 – 5135
Author : – G.Bala Subramanian
Abstract :-
Solar water purification by using the thermal method is used as a principle of solar thermal heating system. Solar thermal systems convert sunlight into heat. “Flat-plate” solar thermal collectors produce heat at relatively low temperatures (80 to 140”F [27 to 60”C]), and are generally used to heat air or a liquid for space and water heating or drying agricultural products. Concentrating solar collectors produce higher temperatures. They are most often used where higher temperature heat is desirable, there are large thermal loads, and/or where there are limitations in the area available for installing solar collectors, since they provide more energy per unit of collector surface area. They can also be applied in the production or refining of chemicals and fuels or to produce mechanical or electrical energy. The following is a discussion of concentrating systems for space or water heating. Such collectors can also be used to reduce heat for absorption cooling
KEYWORDS: solar water heater, parabolic trough, thermal method, low cost, solar water purification.
CHAPTER-III
Design Calculation ________________________________________
3.1. Pump Calculation
For laminar flow of fluid, the roughness of the pipe can be neglected. For water at 20”, ” = 0.01poise, ” = 1000 kg/m3.
Re = (” v1”d1)/”
If Re < 2300 then it is a laminar flow.
” = 64/Re
v2=sqrt((2hg)/(1+(4”(d2/d1)2)))
Considering the required head to be more than 20% to
account for friction losses. The design head would be,
(h)=1.2”h
3.2. Power of the motor
P = ”g”Q”(h)
3.3. Battery selection
A 12 V, 9 Ah lead acid batteries is selected. Its rating is, P = V”I = 12”9
P = 108 Watt-hr
3.4. Solar panel selection
The selection of solar panel is done by considering the weight criteria as well as its ability to charge the battery. The current produced by the solar panel was calculated by knowing the maximum power (P) of the solar panel and the voltage rating (V) of the battery. Charging time (T) was computed by the ratio of battery rating (Ah) to the total current produced by the solar panel.
Table 1 Solar panel selection
Sr.No. Solar I =P/V T = Ah/I Weight
panel (amps) (hrs) (kg)
rating
(watts)
1 6 6/12 = 0.5 9/0.5 =18 0.6
2 8 8/12 = 0.67 9/0.67=13.5 0.8
3 10 10/12 = 0.83 9/0.83= 10.8 1.2
4 15 15/12 = 1.25 9/1.25 = 7.2 1.5
5 20 20/12 = 1.67 9/1.67 = 5.3 2
6 30 30/12 = 2.5 9/2.5 = 3.6 3.6
7 40 40/12 = 3.33 9/3.33 = 2.7 5
From the Table 1, it is observed that as the rating of solar panel increases its weight increases but the time for charging the battery decreases if the solar panel is operating at its maximum rating. Thus, by considering weight and charging time as the criteria, 20 watt rating solar panel was selected for our system
CHAPTER-IV
3D Design and Drawing ________________________________________
4.1. Main Assembly
4.2. Battery
4.3. Main Frame Structure
4.4. Solar Penal
4.5. DC Pump
4.6. Water Tank
CHAPTER-V
Component Specification ________________________________________
5.1. Tank
PVC, 16 lit, 1 kg
5.2. Solar panel
20W PV solar panel
Dimension: 49”35”3 cm
Weight :2 kg
Max voltage : 17 V
Max current : 1.18 A
Open circuit volt: 21 V
Short circuit current : 1.2 A
Tolerance: ” 5%
5.3 Charge controller
Capacity: 12V, 5A Pulse Width
Modulation (PWM) technique
5.4. Battery
Sealed Lead Acid battery
Capacity : 12 V, 9 Ah
Dimensions : 15”9”6 cm
Weight : 2.5 kg
Constant voltage charge with regulation
Standby use : 13.5 V- 13.8 V
Cycle use: 14.5 V ‘ 14. 9 V
Max initial current : 2.4 A
5.5 Motor with Pump
Brushless DC motor
Capacity :12 V, 2.2 A
RPM :0-6000
Dimensions: 17”6”6 cm
Weight : 550 gm
Max discharge :3 ltr/min
Max pressure: 80 psi
In built operating pressure switch
to cut off the pump from the motor
when the pressure exceeds the max
value.
5.6. Pipe & Connector
Diameter: 11 mm
Length: 2 m
5.7. Water Filter
5.8. Body Frame
a) Material- Mild steel
5.9 Metal Plate
a) Square of mild steel.
5.10. Nut and Bolts
CHAPTER-IV
Construction and Working ________________________________________
6.1. Experimental Setup
The schematic of experimental set up. The experimental set-up consist of a solar photovoltaic panel of 20 watt for 12 volt DC mini solar system. The number of cells in this panel is 36 and the maximum power output from the panel is 20 Watt and 17.3 volts. It consists of three filters i.e. first filter which is pre carbon filter. Pre carbon filter absorbs and eliminate any chlorides and organic chemicals from water. Second filter eliminates various foreign bodies that come from service water pipes such as bits of rust. The third filter is the reverse osmosis pump membrane filter, once the water passes through the RO pump it passes through this membrane filter.
The solar charge controller consists of voltage converter. It is used to regulate the power going from the solar panel into the batteries .The rated solar input is 4.5 Amps, the regulation voltage is 14.1 volts. The reverse current leakage is less than 10 mA. The experimental set up has a Reverse osmosis booster pump. The model number is HT-75, normal flow rate through this pump is 1.0 lit/min and the minimum voltage required for its operation are 12 volts DC. The ultraviolet tube which is used for this experiment is of 9 watt capacity. Sheet metal tanks are installed in the experimental set up of 27 liters capacity.
6.2. Working
The set up is placed on a flat surface. Photovoltaic panel along with the along with the set up can be placed separately in the sunlight for battery charging purpose. Water and electrical connections are checked properly for any leakages .The water to be purified should be filled in the top plastic tank .As the water starts flowing from the pipe the purging of all the three filters are done for avoiding air lock. Impure water first passes through the pre carbon filter, this filter effectively removes chlorine sediments and volatile organic compounds from impure water. Once the water comes out from the pre carbon filter it goes inside the sediment filter where the hard water gets soften into soft water. This sediment filter adsorbs the mineral sediments which makes the hard water into soft water and does not allow the minerals to get deposited inside the reverse osmosis pump. The water then passes through the reverse osmosis pump where it gets pressurized to 12.5 bar and passes through the reverse osmosis semi permeable membrane where water soluble organics are removed .The water then passes through the ultraviolet lamp sterilizer where most of coli form ,viruses and protozoa are destroyed .Total load on the system is 19 watts ,total watt hour rating is 57 watt hours. Actual output of PV panel is 19 watt and power used at the end is 15.40 watt .Energy produced by one 20 watt panel in a day is 61.6 watt- hour .Hence the number of PV panels required for this experimental set can be calculated as the energy produced by one 20 watt panel in a day divide by total watt hour rating and it comes to 1.08. Therefore one panel is required for charging a battery of 12 volts and 12.5 amps for its operation for 3 hours.
‘
PHOTOS:-
Final Costing ________________________________________
Sr. No Part Name Quantity in KG/Piece Amount in RS
1 Tank 1 nos 200
2 Solar panel 1 nos 2800
3 Charge controller 1 nos 200
4 Battery 1 nos 1600
5 Motor with Pump 1 nos 2400
6 Pipe & Connector 8 meter 200
7 Water Filter 1 nos 2500
8 Body Frame 5 kg 500
9 Metal Plate 2 kg 100
10 Nut and Bolts 100gm 50
Total Cost
10550
Conclusion ________________________________________
In this project our main goal is to spray water and also purify the water with the help of solar energy. And after all doing all Experimental and manufacturing process this goal is achieved. We need to charge the battery for 8 hour to operate the pump for the water spraying and also to filter the water. And this energy easily available from the sunlight and we required 10-15 watt power photovoltaic electric cell means solar penal.