1. GAURAV JHANWAR

2. 1. What is WTP 2. Benefits of water monitoring. 3. Monitoring methods 4. Various instruments 5. Conductivity and it’s Working 6. How ph meter works 7. Operation of turbidity 8. working of 02

3. A water treatment plant is a physical plant where various physical, biological or chemical processes are used to change the properties of the water (e.g. by removing harmful substances) in order to turn it into a type pure water which can more acceptable for an end-use, which may be drinking, industry, or medicine. Two of the main processes of industrial water treatment are boiler water treatment and cooling water treatment. A lack of proper water treatment can lead to the reaction of solids and bacteria within pipe work and boiler housing. Steam boilers can suffer from scale or corrosion when left untreated. Scale deposits can lead to weak and dangerous machinery, while additional fuel is required to heat the same level of water because of the rise in thermal resistance.

4. Benefits of proper monitoring water treatment program include: Reduced risks associated, with chemical underfeed or overfeedReduced risks associated, with chemical underfeed or overfeed Manage quality according environmental regulationsManage quality according environmental regulations Improved quality of plant operationImproved quality of plant operation Increased water and energy savingsIncreased water and energy savings Improved plant productivityImproved plant productivity

5. How we can monitored MONITORING METHODS: MANUAL MONITORING CONTINOUS ONLINE MONITORING

6. MANUAL MONITORING 1. Manual monitoring typically involves plant operators or technicians conducting chemical tests and comparing the results to specified chemical control limits. The testing frequency can vary from once per day to once per hour, depending on the plant resources available. The tests run can include pH, conductivity, suspended solids, alkalinity, hardness, and others. Using the test results, the plant operator manually adjusts a chemical feed pump or blow down valve, making an estimate of the degree of change necessary.

7. Manual monitoring is satisfactory for noncritical water systems or systems in which water and plant operating conditions change slowly. Many systems operate with manual monitoring, Typical applications include the following: closed cooling water treatment systems low to medium pressure boilers

9. CONTINUOUS, ON LINE MONITORING Because of the dynamic nature of many water treatment systems and the worldwide need for improved reliability and quality, a higher degree of precision is required in the monitoring and control of water treatment programs than that obtained through manual monitoring. To achieve the degree of precision needed, continuous on-line monitoring with automatic instrumentation is required.

10.  Control valves  Flow Tx, level Tx, Pressure Tx  Sov’s  Conductivity analyzer  Ph analyzer  Turbidity measurement instrument  Dissolved oxyzen analyzer

11. Conductivity Electrical Conductivity is the ability of a solution to transfer (conduct) electric current. It is the reciprocal of electrical resistivity (ohms). Electrical conductivity can therefore be used as a measure of the concentration of ionizable solutes present in the sample the unit of measurement commonly used is: (micro-Siemens per centimeter or µS/cm )

12. . How is conductivity measured The electrical conductivity of a solution of an electrolyte is measured by determining the resistance of the solution between two flat or cylindrical electrodes separated by a fixed distance. An alternating voltage is used in order to avoid electrosis. The resistance is measured by a conductivity meter. Conductivity may be measured by applying an voltage (V) to two electrodes immersed in a solution and measuring the resulting alternating electrical current (I). During this process, the cations migrate to the negative electrode, the anions to the positive electrode and the solution acts as an electrical conductor.

15. PH & It’s measurement pH is a measure of the acidity or alkalinity of a water solution. The acidity or alkalinity of a water solution is determined by the relative number of hydrogen ions (H+) or hydroxyl ions (OH-) present. Acidic solutions have a higher relative number of hydrogen ions, while alkaline (also called basic) solutions have a higher relative number of hydroxyl ions. Acids are substances which either dissociate (split apart) to release hydrogen ions or react with water to form hydrogen ions. Bases are substances that dissociate to release hydroxyl ions or react with water to form hydroxyl ions.

16.  Parts of a PH probe ◦ PH electrode ◦ Reference electrode ◦ Temperature sensor (optional)  The two electrodes generate the voltage difference to be measured

17. PH ANALYZER OPERATION When one metal is brought in contact with another, a voltage difference occurs due to their differences in electron mobility. A pH meter measures essentially the electro-chemical potential between a known liquid inside the glass electrode (membrane) and an unknown liquid outside. When we place the probe or probes into a solution, the hydrogen ions in the solution will move toward the glass electrode replacing some of the metal ions on the glass coating. This will cause a tiny voltage across the glass bulb. This voltage is picked up by the silver wire and passed to the voltmeter where the voltmeter will amplify and change the voltage value into a value we can use, pH units. The greater the concentration of hydrogen ions the greater the increase in voltage will be. This greater voltage corresponds to an increase in acidity causing the reading on pH meter to decrease. Remember the more acidic the lower the pH value. Similarly a decrease in hydrogen ions or increase in hydroxide ions indicates an increase in alkalinity, causing a decrease in voltage and therefore an increase in the pH reading.

18. The pH meter measures the electrical potential (follow the drawing clock-wise from the meter) between the mercuric chloride of the reference electrode and its potassium chloride liquid, the unknown liquid, the solution inside the glass electrode, and the potential between that solution and the silver electrode. But only the potential between the unknown liquid and the solution inside the glass electrode change from sample to sample The glass electrode consists of a sturdy glass tube with a thin glass bulb welded to it. Inside is a known solution of potassium chloride (KCl) buffered at a pH of 7.0. A silver electrode with a silver chloride tip makes contact with the inside solution. To minimise electronic interference, the probe is shielded by a foil shield, often found inside the glass electrode. Most modern pH meters also have a thermistor temperature probe which allows for automatic temperature correction, since pH varies somewhat with temperature.

20. Turbidity Turbidity is caused by suspended matter and can be defined as a lack of clarity in water. Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. The methods used for continuous measurement of turbidity is “ nephelometric method.”

21. Nephelometric method In the nephelometric method, the sample flows through a cell. Near the midpoint of the cell, a light source sends a beam of light into the moving fluid. Light receivers are located at various positions in the cell. The receivers measure the amount of light scattered 90° from the incident light. The amount of light scattered increases as the turbidity in the sample increases. The instrument measures the scattered light and develops a signal that is related to nephelometer turbidity units (NTU).

24. Dissolved Oxygen The ability to measure dissolved oxygen is very important, especially in boiler systems, where oxygen corrosion can be very damaging. The sensor measures the dissolved oxygen concentration and transmits a signal, proportional to the oxygen concentration, to the analyzer. The analyzer provides a readout in parts per billion or parts per million and an output that can be connected to a recorder or data logging device.

25. O2+2H2O+4e- ®4OH - dissolved oxygen water electrons hydroxide ions Dissolved oxygen is commonly measured by a membrane-isolated electrochemical cell. This cell contains a cathode, an anode, and an electrolyte solution. A gas-permeable membrane admits the dissolved oxygen from the sample to the electrodes. There, an electrochemical reaction generates an electric current with a magnitude proportional to the dissolved oxygen concentration. The reaction can be summarized by the following equation:

26. For dissolved oxygen analyzer calibration, the sensor is exposed to humid air. The concentration of dissolved oxygen in the moisture is between 8 and 10 ppm, depending on the ambient pressure and temperature. The analyzer reading is adjusted to the correct value for the pressure and temperature. Some analyzers have an automatic calibration feature that measures the temperature and pressure at the push of a button.