UNIT 8 - POLLUTION AND SOLID WASTE MANAGEMENT SYSTEM

Introduction

• Pollution is the introduction of contaminants into the natural environment that cause adverse change, in the form of killing of life ,toxicity of environment , damage to ecosystem and aesthetics of our surrounding . 
• An unwanted change in the environment which involves the physical, biological and chemical changes involving air, water and land which affects the human life in one way or the other”.
• Pollution has become a serious issue after World War II in developing countries due to unchecked rapid industrialization. 
• Pollution is the root cause of many diseases that kill and disable living organisms.
• Contamination by Industries Pollution is everywhere.....

 Types of Pollution

❖Air Pollution.
❖Water Pollution.
❖Noise Pollution.
❖Littering (spilling of oils in oceans)
❖Soil contamination (by lead, heavy metals)
❖Radioactive contamination.
❖Thermal pollution.
❖Visual Pollution.

 AIR POLLUTION 

Air pollution is contamination of the indoor or outdoor environment by any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere.

Sources Of Air Pollution 

•  Household combustion devices. 
•  Motor vehicles. 
•  Industrial facilities. 
•  Forest fires 

Pollutants causing Air Pollution…… 

•  Include particulate matter.(Particulate matter is the sum of all solid and liquid particles suspended in air many of which are hazardous. This complex mixture includes both organic and inorganic particles, such as dust, pollen, soot, smoke, and liquid droplets.) 
• Carbon monoxide.
• Nitrogen dioxide 
• Sulfur dioxide 

Harmful effects of Air Pollution

• Effects on cardiovascular health
• Effects on breathing (asthma).
• Links to cancer
• Effects on children 

How to control air pollution?

•  Maintaining a healthy distance between the industrial and residential areas. 
• The chimneys should be constructed tall in size so that the emissions must be released higher up in the environment 
• The sulphur must be removed after burning.
• The gasoline must have anti knocking agents.. 
• The mining area should be planted with trees. 
• The coal fuel should be replaced with gas fuel to control the air pollution. •
• The automobiles must be designed with emission control system. 
• The wastes must be removed and recycled in the industrial plants and refineries.
• Plants like pine and ribes need to be planted to metabolize the nitrogen oxides and other pollutants.
• Timely servicing of the car helps to keep it in a good condition, and also minimizes fuel exhaustion
• Using public transportation helps to prevent the air pollution 
• Using alternative energy sources like solar energy, hydroelectric energy, and wind energy 

WATER POLLUTION 

•  Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans, aquifers and groundwater).  
• Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds. 
• Water pollution affects plants and organisms living in these bodies of water. 
• In almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities.

Polluted Water comes from ....

• Domestic sewage. 
• Industrial wastewater.
• Agricultural wastewater.
• Construction site stormwater. 
• Urban runoff (stormwater). 
• Petroleum hydrocarbons
• Plastics 
• Pesticides 
• Heavy metals 
• Sewage
• Radioactive waste 
• Thermal effluents Water Pollutants…
• Detergents 
• Chloroform 
• Food processing waste, (fats and grease)
• Insecticides and herbicides. 
• Petroleum hydrocarbons, (gasoline, diesel fuel, jet fuels, and fuel oil).
• Lubricants (motor oil). 
• From stormwater runoff.

 Preventing Water Pollution… 

• Conserve water by turning off the tap.
• Mind what you throw down your sink or toilet. 
• Don’t throw paints and oils in water channels. 
• Use environment friendly household products, such as washing powder, household cleaning agents etc.
• Take great care not to overuse pesticides and fertilizers. 
• Don’t throw litter into rivers, lakes or oceans.
• Help clean up any litter you see on beaches or in rivers and lakes, make sure it is safe to collect the litter and put it in a nearby dustbin. 

Treating Polluted Water

• Suspended, solid particles and inorganic material can be removed by the use of filters.
• Use of biological filters and processes can naturally degrade the organic waste material.
• After above two steps chemical additives are supplied to get rid of any left-over impurities. 

LIGHT POLLUTION 

Light pollution, also known as photo pollution or luminous pollution, is excessive, misdirected, or obtrusive artificial light.

 Light pollution Causes..

• Degradation of photic habitat by artificial light.
• Artificial Lights Disrupt the World's Ecosystems. 
• Nocturnal animals sleep during the day and are active at night.
• Light pollution radically alters their nighttime environment by turning night into day. 
• Artificial lights disrupt this nocturnal activity, interfering with reproduction and reducing populations. 

 Controlling Light Pollution.. 

• Excessive lighting should be avoided. 
• For Lighting an applicable design should be followed. 
• Light engineering should be applied for streets.

NOISE POLLUTION 

• Noise pollution is displeasing or excessive noise that may disrupt the activity or balance of human or animal life.
• Noise means disgust or discomfort hearing from environment. 

Sources of Noise Pollution

•  Machines.
•  Transportation systems.
•  Motor vehicles.
•  Aircrafts. 
• Trains.
• Poor urban planning. 

Effects of Noise Pollution

• Noise pollution affects both health and behavior. 
• Unwanted sound (noise) can damage psychological health.
• Noise pollution can cause
• Annoyance 
• Aggression . 
• Hypertension . 
• High stress levels .
• Hearing loss.
• Sleep disturbances, and other harmful effects. 
• Chronic exposure to noise may cause noise-induced hearing loss.
• Older males exposed to significant occupational noise demonstrate significantly reduced hearing sensitivity than their non-exposed peers. 

SOIL POLLUTION 

• Soil contamination or soil pollution is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. 
• It is typically caused by industrial activity.
• Agricultural chemicals. 
• Improper disposal of waste. Soil Contaminating Chemical
• Petroleum hydrocarbons.
• Poly nuclear aromatic hydrocarbons. 
• Pesticides 
• Lead and Other heavy metals.

How to control soil pollution? 

• Limit the use of fertilizers and pesticides 
• Awareness about biological control methods and their implementation 
• The grazing must be controlled and forest management should be done properly
• The afforestation and reforestation must take place 
• Proper preventive methods like shields should be used in areas of wind erosion and wind breaks 
• Treating Wastes of industries. 
• Treating nuclear waste.
• Proper disposing of plastics and other garbage materials. 

Thermal Pollution 

• Thermal pollution is the degradation of water quality by any process that changes ambient water temperature.
•  A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers.
• When water used as a coolant is returned to the natural environment at a higher temperature, the sudden change in temperature decreases oxygen supply and affects ecosystem composition.
• Fish and other organisms adapted to particular temperature range can be killed by an abrupt change in water temperature (either a rapid increase or decrease) known as "thermal shock."

Solid waste and its management

Solid Waste

Solid waste is any non liquid, non soluble material ranging from municipal garbage to industrial wastes .

Solid waste includes

• Garbage
• Rubbish
• Demolition products
• Sewage treatment residue
• Dead animals
• Manure and other discarded material

Solid waste poses serious threat to the environment globally.

Types of Solid Waste

BIODEGRADABLE:

• Biodegradable wastes are such waste materials which are and can be degraded by natural factors like microbes (e.g. bacteria, fungi and few more), abiotic elements like temperature, UV, oxygen, etc. 
• Some examples of such wastes are food materials, kitchen wastes and other natural wastes. 
• Microorganisms and other abiotic factors together break down complex substances into simpler organic matters which eventually suspend and fade into soil. 
• The whole process is natural which can be rapid or slow. Therefore the environmental issues and risks caused by biodegradable wastes are low.

NON - BIODEGRADABLE:

• Unlike biodegradable wastes, non-biodegradable cannot be easily handled. 
• Non-biodegradable wastes are those who cannot be decomposed or dissolved by natural agents. 
• They remain on earth for thousands of years without any degradation. Hence the threat caused by them is also more critical. 
• A notable example is the plastics which are a commonly used material in almost every field. 
• To give these plastics a long lasting effect, improved quality plastics are being put to use. This made them more temperature resistant and more durable even after use. 
• Other examples are cans, metals, and chemicals for agricultural and industrial purposes. They are the main causes of air, water and soil pollution and diseases like cancer.

Solid Waste Management in Hotels and Restaurants

• Huge volume of solid waste is generated everyday in a hotel. Many of them, particularly organic wastes, comes from kitchen and restaurant residues.
• Waste paper and other consumables from the other departments also form  substantial amount of solid waste.
• They pose a huge environmental and sanitation problem if not collected and disposed properly.

Collection of hotel and restaurant waste

• Hoteliers may make their own arrangements for collection of waste individually by big hotels or through their own association for a cluster of hotels, particularly in tourist places.
• The MC may extend help in primary collection of solid waste on full cost recovery basis.
• Charges for the collection of hotel waste may depend upon the quantity of waste to be picked up from the hotels and restaurants and frequency of collection required.

If local authorities are not taking care of the collection and disposal of solid waste from hotels then the hotel has to make its own arrangements for such disposal. They may choose one or a combination of following methods for waste disposal.

• Incineration
• Pulverisation
• Mechanical Compost Plant
• Trenching
• Controlled tipping
• Disposal into sea.
• Filling of low-lying are or landfill.

Methods of Solid Waste Disposal

INCINERATION: It is a waste treatment process that involves the combustion of organic substances contained in waste material.

PULVERISATION: In this method, waste is simply pulverized into powder form without any chemical change. The powder thus formed may be used as manure or discharged through sewage line.

MECHANICAL COMPOST PLANT: A compost plant converts the garbage into manure, which is rich in nitrogen. This is the most hygienic method of waste disposal but only for organic wastes.

TRENCHIG: In this method, waste is dumped in a trench and buried under soil. The garbage is converted to compost.

CONTROLLED TIPPING: This method is employed where land is available for redevelopment. Waste is tipped from dumper into hollow spaces in the ground about 4 to 7 feet deep and then buried under ground.

DISPOSAL INTO SEA: This method is relevant and available only to hotels near  a sea. This is quite cheap but in times the non-soluble garbage may come back to the shore and cause problems.

FILLING OF LOW LYING AREAS: Waste is dumped into low-lying areas.

Pollution and the Hotel Industry

• Pollution of various forms is a cause of great concern for existence of life on the earth. One of the most disconcerting effects of pollution is global warming. Other direct effects include increasing health problems, mental stress and strain, increase in the number of endangered species, ecological imbalance among others.
• Hotels are properties where very high intensity of human and machine activities occur day in and day out. This is bound to produce all sorts of pollution and is subject to very stringent pollution control measures.
• In tourist destinations, there will be surface transport carrying guests to and from  the hotels, thereby causing great pollution from automobile emission.
• Hotel  Industry contributes to the following types of pollution:
• Water pollution
• Air pollution
• Soil  pollution
• Noise  pollution

Hotels and Water Pollution

• Rampant discharge of waste water and effluents into water bodies has played havoc with hygiene and ecology.
• Waste water disposal without proper treatment has severely  affected marine life and living of  downstream people using the water bodies for economic as well as day to day use of water.
• Discharge of hot water also produces pollution in changing the aquatic environment of water bodies.
• Hotels produce a lot of waste water and many of them have now installed their own STP, which contributes greatly in reducing pollution as well as gaining economy by way of reuse of clear water.
• This pollution can be minimized at the source by restricting chemicals that mix with water.

Hotels and Air Pollution

• Hotels liberate gases and contaminated air from various utilities, such as kitchen gas and firewood ovens, fume from materials being cooked, boiler and diesel generating  set  exhausts, and release of refrigerant CFC, if there is any leakage.
• If the boiler is fired with pulverized (powdered) coal, the exhaust gas will have a lot of dust particles leading to air pollution.
• Diesel engines also produce pollutants such as carbon dioxide, carbon mono oxide and oxides of nitrogen.

Hotels and Soil Pollution

• Hotels contribute to soil pollution by dumping their solid waste and sludge into the soil.
• Excessive dumping of untreated or semi treated sewage and sludge may lead to contamination of soil and also produce foul odour.

Hotels and Noise Pollution

Hotels have quite a few noise generating sources such as engines, pumps, motors etc. And sound produced in banquet halls.

Liquid Waste (Sewage) its treatment and disposal

• Hotels produce a lot of waste water and usually the waste water is disposed off in water bodies such as river, sea, lake or as landfill.
• But acc. to the norms of the PCB (Pollution Control Board) , sewage needs to be properly treated before it is disposed.

SEWAGE TREATMENT:

It is the process of removing the contaminants from sewage to convert it to a composition of clear liquid and solid, which are fit for discharge to the environment or for reuse.

SEWAGE TREATMENT PLANT

• In the most sophisticated treatment, clear potable water can be obtained while leaving only 5 per cent to 10 per cent of solids after treatment.
• This solid part, called sludge, is further processed to produce what is called biosolid, which have many uses.
• While hoteliers can discharge their sewage to the public sewerage, along with town sewage, for treatment in the city sewage treatment  plant and final disposal.
• Many hotels have opted for in-house, Sewage Treatment Plants, where they get fresh water for reuse and may use the sludge as manure for garden activities.
• The fundamental  principal of purifying sewage is to completely break down the original organic matter  in it by the action of microorganisms (bacteria). These microorganisms digest (eat away) the original organic matter leaving a clear effluent and solids.

The stages in treatment of sewage are as follows:

1. Primary Treatment: This removes the suspended and floating objects by means of strainer, screens, grit chamber, sedimentation tanks, septic tanks, etc. The typical materials that are removed in this stage include large objects such as sticks, rugs, rocks, sand, gravel, fats, oils, grease etc.
2. Secondary Treatment: This treatment  is designed to degrade the biological and organic content of the sewage by means of microbial action. The bacteria present in the sewage consume all the organic matter.
3. Tertiary process with or without disinfectant: The final treatment is performed at this stage before making eventual disposal of the treated wastewater. Tertiary treatment comprises of many processes and includes filtration, disinfection and removal of nutrients such as nitrogen and phosphorus which encourage algae formation.  Disinfection can be done with chlorine, ozone and ultraviolet treatment. In many cases, disinfection  is done as the last activity (also called effluent  polishing). The purpose of disinfection is to destroy residual bacteria in water after secondary treatment, thus rendering it very safe for final disposal.

Sewage Treatment Plant

Methods of Sewage Disposal

Sewage  disposal is broadly classified  into the following types:

Methods of Sewage Disposal

Dilution – Raw sewage or partly treated sewage is thrown into natural water bodies such as sea, river, lake, marshy land, etc. Self-purification is the mechanism in this process, which is helped by the following factors:

• Dilution of contaminants by dispersion in flowing water.
• Sedimentation of particles to the water bed.
• Oxidation of organic matter by dissolved oxygen in water.
• Sunlight, which kills harmful bacteria.
• Microbial organisms consuming the solid organic matter in sewage.

Purification – This process comprises of a change in the chemical and biochemical character of the sewage in a treatment plant and is effected through one or a combination of the following processes:

LAND FILL AND IRRIGATION:

Raw or partly treated sewage is dumped on land. A part evaporates, while a  part percolates. Purification is accomplished by natural oxidation. This is a very good method of sewage disposal where land is available. Bright sunshine helps in microbial activities in the sewage. Decomposed  sewage becomes  an excellent manure for crops. However if harmful bacteria percolate through ground subsoil reaching the ground water , it could contaminate ground water.

Chemical Treatment: Effected by addition of chemicals such as lime, alum etc.

Septic Tank – Used to provide disposal of sewage in a plain sedimentation tank where biochemical reactions (decomposition) also takes place. After decomposition sewage is purified and effluent is taken to soak pits for disposal to city sewers. The solid portion remains in the sceptic tank due to which the septic tank should be cleaned after a period of 5 to 10 years.

Bio – aeration – The sewage is first passed  through coarse screens to get rid of large solids. The sewage is then treated in the main aeration tank with compressed air.

GREEN HOTELS

Green” hotels are environmentally friendly properties that take the initiative and implement very important practices and programs to reduce energy, water, and waste. 

Green Hotels are participating in recycling programs, linen changing programs, installing energy efficient lighting, and getting their message out to their guests and how they are doing their part in protecting the planet.

Ways to control pollution in hotels

1. Install Energy Saving Technologies

It has been estimated that 75% of hotels' environmental impacts can be directly related to excessive consumption—including energy consumption. Installing energy-efficient technologies such as appliances, lighting, and heating and cooling systems can make a difference for both the environment and your hotel's bottom line. 

2. Embrace Recycling

Another huge impact the hospitality industry has on the environment is due to the amount of waste hotels create. It's time to embrace recycling, and we're not just talking about using cloth napkins instead of paper.

According to the Green Hotels Association, a hotel in Toronto is recycling stained tablecloths into napkins, chef's aprons, and neckties, while other hotels are making cloth laundry bags from retired sheets. These are the sort of initiatives that can make a long term difference when put into practice.

3. Encourage Guests to be Green

Put cards in each room asking guests to turn out the lights when they leave, or reuse towels if possible. Make recycling bins readily available to guests and be sure that they are aware of your green programs. When guests see that your hotel is making an effort to help the environment, they will want to do their part as well. 

For those hotels looking to do even more, consider loaning or renting bicycles to guests, or look into installing a bike-sharing station. 

4. Start Composting 

An increasing number of hotels are realizing the benefits of composting food waste rather than throwing it out. Not only is it a popular and well-known green initiative that will impress your guests, it can save your hotel money on landscaping since composted waste can be used as organic fertilizer.

5. Save Water

There are so many ways hotels can save water: Installing toilet tank fill diverters in older toilets can save about 3/4 of a gallon of water per flush. Transitioning to nearly waterless laundry machines can save 80% of hotel water usage. Making water stations available to guests can discourage the use of bottled water. Follow the examples from other hotels that have implemented water-saving initiatives.

6. Plant a Garden

If you're considering expanding your outdoor offerings for guests, consider adding a garden rather than simply extending your patio or pool area. The Green Hotels Association notes that one Pennsylvania property has a 400-foot garden and produces organically-grown vegetables for its restaurant.

Now you don't have to go that far, but even a small garden (perhaps even on the rooftop for those of you with city properties) can help counteract your hotel's carbon footprint. Raised beds can be installed almost anywhere, and placing benches—made from recycled materials—around a garden can make for a wonderful guest experience.

7. Support Local, Sustainable Businesses

Hotels can help reduce their environmental impact by making smart purchasing choices as well. A hotel can reduce waste generation by making an effort to only purchase environmentally-friendly products, and purchasing locally can also reduce the impact on the environment and benefit the community. 

You may also want to consider promoting other environmentally-friendly businesses to guests, such as local farm-to-table restaurants.

8. Implement Alternative Energy Sources

A number of hotels have switched at least portions of their energy usage to alternative sources, with great results. The Willard Intercontinental in Washington D.C. is now running on 100% wind energy power, resulting in a 12% decline in energy consumption, according to the Green Hotels and Responsible Tourism Initiative. Other hotels, particularly those in warmer climates, are making use of solar energy for signage and water heating. And as the market for alternative energy increases, more solutions will arise. 

9. Take Care of Your Linens

We already mentioned recycling linens as a way to limit waste, but what about extending the life of those linens in the first place? Using laundry processes that limit the wear and tear on your linens can keep replacement costs, and your hotel's environmental impact, down.

UNIT 5 - WATER SYSTEMS

Necessity of Water

• In the hospitality industry water is used in a number of ways starting from supplying bacteria free clean drinking water.
• Hot and cold water in bathrooms and toilets.
• In kitchens for cooking food.
• Water is also needed in the laundry.
• For cleaning floors and articles.
• For water sprinkler system.
• For Swimming pools.

Availability of Water in Hotels

• Water in the hospitality industry is generally supplied by the Govt. Dept.
• But since hospitality units require quite large amounts of water they are required to have buffer stock of water and for which large tanks and reservoirs are required.
• Hospitality units generally have their own stand by arrangement for water supply in the form of bore wells.
• Bore wells are to be dug with the permission of local civic authorities and they charge yearly rent for bore well.
• Since the bore well provides hard water the hotel has to invest in a water treatment plant.
• The water is supplied to the various locations in the hotel by means of a large network of pipes, pipe fittings, valves etc.

Hardness of Water

• Water is termed as hard when it contains more minerals than ordinary water, especially the minerals – calcium and magnesium.

Types of Hardness in water

• Temporary or Carbonate hardness: it is due to the presence of bicarbonates of calcium and magnesium dissolved in water. Simple boiling removes this hardness.
• Permanent or non-carbonic hardness: it is due to the presence of chlorides and sulphates of both calcium and magnesium. Simple boiling cannot remove his hardness. Use of chemicals and ion exchange methods are used to remove the permanent hardness.

Ill – Effects of Hard Water

• It produces less lather with soap, resulting in more soap consumption.
• It produces soap cum, which produces a dirty feeling during and after bath and wash.
• It causes scale formation inside the water boilers and boiling utensils and thus results in corrosion and reduces the heat transfer efficiency.
• It causes turbidity during boiling of water.
• It affects the taste and structure of cooked food.
• Too much intake of hard water affects the digestive process in human beings. It also leads to other heath issues.
• It dis colours fabric.

Method of removing temporary hardness of water

Temporary hardness of water can be removed by Boiling or by adding lime to water (CaO).
Water containing Calcium bi carbonate on heating results in the following products.
BY BOILING:
Ca(HCO3)2 + Heat ------------------> CaCo3 + Co2 + H2O

Mg(HCO3)2 + Heat -------------------> MgCO3 + CO2 +H2O

Calcium and Magnesium carbonates are insoluble in water, and hence accumulate as thick white precipitate at the bottom and can be removed in the sedimentation tank. The CO2 formed is liberated as gas.

Addition of Lime (also called Clarke’s process):

Lime also known as Calcium Oxide (CaO) when added to hard water results in the following reaction.
Ca(HCO3)2 + Ca(OH)2  ------------------>2 CaCo3 + 2H2O

Mg(HCO3)2 + Ca(OH)2 -------------------> Mg(OH)2 + 2CaCO3 +2H2O

Calcium and Magnesium carbonates are insoluble in water, and hence accumulate as thick white precipitate at the bottom and can be removed in the sedimentation tank.

Method of removing permanent hardness of water

Permanent hardness can be removed by certain special methods, generally called water softening methods. The basis principal of softening is the same i.e. converting soluble Ca and Mg salts in hard water into corresponding insoluble salts ad finally removing the precipitate. The six methods, which are commonly used for softening permanent hardness, are as follows:

1. Zeolite/ Permutit /Base Exchange Process.
2. Washing Soda Process
3. Lime Soda Process
4. Caustic Soda Process
5. Ion -  exchange process or demineralization (DM) process.
6. Calgon Process

Zeolite / Permutit/ Base Exchange Process

• A zeolite softener resembles a sand filter in which the filtering medium is zeolite ( a naturally occurring green salt generally termed as green sand) rather than sand.
• Chemically represented as Na2O.Al2O3.4SiO2.2H2O
• It is manufactured synthetically under the name ‘Permutit’ which is chemically known  HYDRATED SODIUM ALUMINIUM ORTHOSILCATE 
• The hard water enters through the top and is evenly distributed on the entire zeolite bed. As the hard water passes through the zeolite the hardness causing ions (Ca+2, Mg+2 etc.) are retained by the zeolite as CaZ and MgZ respectively, while the outgoing water contains equivalent amount of sodium salts. 
• The sodium ions of the zeolite get replaced by calcium and magnesium ions of the hard water forming insoluble calcium zeolite and magnesium zeolite.

Na2Z + Ca or Mg salt ----------------------> Na2 salt + Ca or Mg zeolite.

After a few days of operation, all the active sodium zeolite changes to Ca and mg zeolite.
To replenish the Zeolite bed with Na ions The zeolite bed is treated with 10 % solution of NaCl (brine solution).
This process is known as regeneration.
The regenerated zeolite is now ready to be used for water softening again.
The rate of filtration through zeolite is about 300 litres per square metre per minute.

Zeolite / Permutit/ Base Exchange Process

Advantages of the Zeolite / Permutit/ Base Exchange Process

• Zero hardness can be obtained.
• The plants are compact, automatic and easy to operate.
• The running, maintenance and operation (RMO) cost is quite less.
• It also removes iron and manganese from water.

Washing Soda Process

In this process Washing Soda (Na2CO3) is added to hard water which results in formation of insoluble Ca and Mg salts which form a precipitate.

Caustic Soda Process:

In this process Caustic Soda (NaOH) is added to hard water which results in formation of insoluble Ca and Mg salts which form a precipitate. This process can be used to remove temporary as well as permanent hardness of water

Lime Soda Process:

In this process along with Washing Soda (Na2CO3) , Lime (CaO) is also added to hard water which results in formation of insoluble Ca and Mg salts which form a precipitate.

Calgon Softener:

This method makes use of Sodium Hexametaphosphate (NaPO3)6.

Ion Exchange Process

Method of functioning is very similar to the Zeolite process, main difference being that in this process, Hydrogen is exchanged instead of Sodium. It makes use of the resins, Phenol-formaldehyde ( C8H6O2)

Cold Water Distribution System in a Hotel

Cold Water Distribution System in a Hotel

Cold Water Distribution System in a Hotel

1. Raising Main – It is a supply pipe line that rises from ground level to the storage tank on the roof top. Since the supply pressure is not enough, there are intermediate booster pumps to enable the water to reach the top storage tanks. Some times intermediate storage and multiple tanks are used for serving a group of intermediate floors. The water is stored in the storage tank through the raising main, the storage tank is located at the highest point in the building to ensure  a reasonable pressure in the distribution pipes .
2. Discharge or Service Piping – Water for drinking, kitchen and wash basins etc. is directly taken from the rising main by branch pipe at different floors and flows into the service taps. The stop valves should be fitted immediately after the exit from the tanks for disconnecting the pipeline distribution system in case of leakage in tank or pipe system.
3. Valves – are generally gate valves used to completely open or close the water lines .
4. Storage Tanks 

Storage Tank

1. Float Valve / Ball Valve – is a spherical rubber ball at the inlet pipe (at the top of the tank), drops down and opens the inlet when the water level falls and rises as the water level rises and finally closes the inlet when the tank is full. An alarm generally gives the signal that the tank is full.
2. Silencer pipe – This is fitted at the end of the inlet pipe to lower the point of discharge a little above the bottom of the tank. It reduces the water filling noise in the tank.
3. Overflow Pipe – It works when the float valve is out of water.
4. Lid – Covers the tank.

Hot Water Generation and Distribution System:

Cold water raised to a temperature of 38oC is usually considered as hot. The operating temperature range is 49 to 60 degree celcius . In hotels the most prevalent system for hot water are:

• Centralised hot water generation and distribution system.
• Localised hot water generation and distribution system.

Centralised Hot Water System:

This system is usually employed in large hotels. Three different principles  used to generate hot water are:

1. Direct Heating System
2. Indirect Heating System
3. Solar Water Heating System

Direct Heating System

• This system involves natural circulation .
• Hot water from the boiler circulates through a hot water tank called cylinder. 
• Circulation continues because hot water being lighter rises up to the cylinder from the boiler and cold water descends down to the boiler.
• The service pipes are taken from the cylinder to service taps.
• A cold water  system is connected to the boiler from where cold water runs into the boiler via stop valves.
• Whenever there is increase in volume of water and cylinder is unable to accommodate this, the resulting pressure would lead o the possible busting of pipes.
• To avoid this possible bursting, the water is supplied to an overhead cistern.

Disadvantages:

• Oxygen released while heating cold water causes rusting of boiler.
• Boiling can lead to sever scale formation

Indirect Water Heating

• In this system the water cylinder is replaced by a direct heat exchanger called the calorifier where hot water or steam from the boiler enters the calorifier through a coil of tubes and heats the cold water passing through the calorifier.
• Two circulations are followed.
• Primary Circulation – takes place between the boiler and the calorifier
• Secondary Circulation – takes place between the calorifier and service taps.

Solar Water Heating System

• Is the most efficient and eco friendly water heating system. Each evacuated tube is similar to a thermos in principle. A glass or metal tube containing the water or heat transfer fluid is surrounded by a larger glass tube. The space between them is a vacuum, so very little heat is lost from the fluid.
• These collectors can even work well in overcast conditions and operate in temperatures as low as -40°F. Individual tubes are replaced as needed. 
• A solar thermal collector collects heat by absorbing sunlight. A collector is a device for capturing solar radiation.
• The quantity of solar energy striking the Earth's surface (solar constant) averages about 1,000 watts per square meter under clear skies, depending upon weather conditions, location and orientation.

Localized Hot Water System:

Storage Tank Water Heater (Geyser):

• A thermostat controls the temperature of water and it can be heated at any desired temperature.
• There are two light bulbs provided in the geyser. The red bulb indicates the water is being heated and the green bulb indicates that water is heated up to the desired temperature.
• Automatic heating begins if the temperature of the heated water falls below the set level.
• Geysers are used when the duration of hot water supply is limited.
• May require maintenance if hard water is being used.

Tankless Water Heaters:

• When the hot water tap is turned on, water enters the heater.
• The flow sensor detects the water flow.
• The burner is automatically ignited.
• Water circulates through the heat exchanger.
• The heat exchanger heats the water up to the designated temperature.
• When the tap is turned off, the unit shuts down.

SWIMMING POOL MAINTENANCE

• To keep the pool water transparent, sparkling and free from dirt,  filtered water must be used.
• After a specified period of time, usually as recommended by local public health authority, entire water content should be cycled through the filter.
• To ensure proper functioning, the filtration equipment must be cleaned periodically according o a maintenance schedule.
• The process of cleaning the filters is known as backwashing.
• Different types of nets are used to remove floating objects and also large objects that are settled at the bottom of the pool.
• In some pools, the pool water is continuously kept in motion where it passes through the filter and all unwanted floating objects are trapped in the filter.
• The swimming pool has an opening at the water surface level, leading to the drain at the outside. This opening is called WEIR and a strainer is placed at this opening which arrests the objects floating in water, which is subsequently removed.
• Chemicals are added to the pool water to maintain the proper hygienic conditions.
• Disinfectants are added to make the water bacteria free.
• The dosing can be done manually or may be automated.
• To maintain the correct pH level appropriate chemicals are added.
• The pH is normally maintained between 7.2 to 7.6.
• Algae  which are water plants that grow in water, are also very difficult to eliminate. If their growth is not hampered by disinfectants, they are to be manually removed.
• The initial as well as the make up water is supplied to the pool by the water treatment pant in the hotel. 

Basic fittings in the water distribution line

These are fittings in water lines to regulate flow through the lines and are an integral part of any water distribution system.
Taps – a tap is what we see at the draw off end of water service line. Depending upon the directions of water entering the tap and coming out of the tap, they may be categorized as:
1. BIB TAP -  It has a horizontal inlet and free outlet in the form of a bent tube called bib. The bib prevents dust from entering into the free end and contaminating water when it comes out.
2. PILLAR TAP – It has a vertical inlet and horizontal outlet through a bib. They are designed for use in lavatory basins and baths.
Basic fittings in the water distribution line
3. GLOBE TAP – It hasa horizontal inlet and vertical outlet. Previously, these were used in baths and are now largely replaced by pillar taps.
4. SELF CLOSING TAP – This type of tap open when either pulled up or pushed down. Left to itself, it will always close by spring action. It greatly helps in reducing wastage.
5. SENSOR OPERATED TAP – Has a sensor which operates when it detects movement in front of it.

*** For the convenience of guests, the hot and cold taps can be distinguished by a red spot and blue or green spot respectively

VALVES

It is a plumbing device that is used for stopping or fully opening supply to a line or fitting.
They are put in line with the pipe line.
Valves are fitted throughout the water distribution line to facilitate closure of a particular line for maintenance work.
Different types of valves used in a water distribution system are:
Gate Valves.

Globe Valves. ...
Needle Valves. ...
Butterfly Valves. ...
Check Valves. ...
Relief Valves
*** The function of a valve is same as a tap i.e. to open or close or control flow of water.  Tap has a smaller valve and is fitted just before any service utility like basin, shower etc. Valves control flow of water in larger pipe line.

TRAPS
In plumbing, a trap is a device which has a shape that uses a bending path to capture water to prevent sewer gases from entering buildings.
In domestic and commercial applications, traps are typically U, S, or J-shaped pipe located below or within a plumbing fixture.

WATER CLOSETS AND CISTERNS, WASH BASIN