Optimization Of Drinking Water Treatment Process For Stabilization Of Disinfectants: An Essay.

Discuss about the “Optimization of drinking water treatment process for stabilization of disinfectants.

The main objective of this project  is primarily to determine the best method of water treatment optimisation by doing a comparison of the use of Biological Activated Carbon(BAC)only and Biological Activated Carbon that is combined with the Zeolite.

The high population growth rate, rapid industrial development and improved lifestyle has put the demand for clean water at its peak. There is therefore an urgent need to provide clean water at high quantity and quality but at a cheaper cost. For the water to be produced at a lower cost, it is very important that operating expenses in the water treatment plants are seriously reduced. The project puts a lot of emphasis on establishing the safest method that should be considered.

The project will require the following materials for the investigation

Activated carbon

A water Pump

Connection pipes

Castle mountain zeolite

Chemicals

Transparent water containers.

The quality of raw water will be determined and the following parameters will be used for the determination of the water quality.

1PH; the water under study has been taken with a PH of about 7.9 while the typical and recommended PH should be at a range of 7.2-8.8

2 The true colour of the water that is being investigated is at found at 50 Pt-co while the required one should be between 10-200

3Alkalinity(mg/LcaCO3) was at 140 and the recommended range should be from 110-180.

4 Turbidity of water is at 15

5 Hardness of the water under study is at 150 mg/LcaCo3

6 The chloride level is at  190

7 The total organic carbon

8 The bromide level

The raw water has obtained from the lake and that is why it is characterised by the above qualities. The raw water will be passed through a series of stages as the quality is being examined at each stage.

The colloidal particles are removed by the means of chemical addition. The coagulant to be used is aluminium sulphate chemical was preferred for the project due to its availability and low price. The application of this chemical will done according not the jar treatment process. The challenge however will however be to determine the exact dosage for the desired results in regard to the raw water characteristics. In order to predict the allowed level of coagulant dosage, both automatic and manual methods are used. The automatic method is achieved through running of current detectors while the manual one utilised the jar method. The coagulation optimisation is very important because if under dosing is done poor water quality will be obtained. Too much of coagulant leads to other problems related to the water PH and escalates the cost of producing clean water.

Requirements of the Project

The tests done during the filtration process predicts that the water smell and taste could not be removed at the coagulation and filtration stages of the BAC only process. It will be however important that enough contact time with the bed be allowed in order to ensure that effective sedimentation takes place. The project considers giving a contact time of about 20 minutes to ensure that this particular stage serve its purpose. Due to the presence of the micro organisms and other higher forms of lives that are found in the BAC filters, there is a pressure build up in the filters. The frequent and efficient backwashing will be necessary during the experimental analysis. It is expected that this process will be more drastic in warm water than in cold water. The backwashing process is  also done to prevent proliferation of higher organisms in the media hence maintaining very low trophic level.

It is expected that during this backwashing exercise, a mount or the number of the bacteria present are removed but in the cold water. When the filters are backwashed using chlorinated water, it will be much efficient. The level of biological treatment is likely to be lowered if the influent are to be disinfected using chlorine.

The risk of forwarding the bacteria biomass must be assessed when considering the value or quality of the BAC effluent. While we seek to explore this method of water treatment, it is important to note that studies indicate carbon can provide a very good habitat for the bacteria and sufficiently protect them from inactivation during the final stages of post disinfection.

During the project, the sand will be used to provide additional filtration and subsequently prevent the escaping of the carbon particles into the product water. To achieve this effectively a layer of sand must be of considerable amount

The carbon however will be taken due to its inherent ability, good adsorption capacity and the surface chemistry. In general, the most available activated carbons are excellent for production of the treated drinking water. The same perfect results have been obtained in the removal of dissolved organics with the various activated carbon such as coal and wood in the past.

The adsorption capacity of the dissolved compounds is a matter of the concern to the project. At the initial stages of the treatment after backwashing, the adsorption capacity of carbon will be maintained at the effluent quality up to the point of the establishment of the biological activity.

Methodology

A part from the properties of the carbon that are chemical in nature in the other physical properties of carbon such as the bed density, the abrasion resistance and hardness, the ash level and ash constituents have been  looked into as well since they form the initial characteristic limitations of any starting material such as coal.

This is necessary because the bed densities influence the backwashing efficiency, quantity of the final product on the weight basis together with the thermal reactivation yield. The carbon of high bed densities is known for holding very high backwashing velocities. They also allow very high and more flexible thermal reactivation.

Very low carbon losses are likely to be observed in carbons with high hardness and abrasion resistance during the thermal reactivation, backwashing and transfer.

Chlorination

The process of chlorination is a very crucial stage in the treatment of water. A number of measures are taken into consideration in this stage. Laboratory equipment verification, the disinfection of the data handling tools, verification of the online residual products of chlorine, strict adherence to the manufacturers instructions for the use of various instrument calibration, regular checking on the performance of the on-line equipment. The applications of all the manufacturer required level of instrument maintenance. In, order to verify the performance of the online equipment, a potable inspection device is use

The line of operation was as shown below.

When the zeolites is incorporated in the system, a lot of changes are realised. It is expected that it offers a superior performance compared to sand or even carbon filters. The water obtained will be more pure and higher throughput rate that required less maintenance. It is therefore found   a perfect replacement of sand as a filter. Other than performing the function of filtration, this particular mineral usually acts as a catalyst, adsorption tool, an Ion exchanger. The water that will be obtained is likely to be softer softer than the water that is processed in the BAC without Zeolite. The hydrated cation easily exchanges with other ions. This probably explains why the large volumes of this mineral is used in thee manufacture of soap and purification of water.

The adsorption property of the zeolite is always known to be greater than that of the carbon. It can remove water at very low pressures, remove chemicals from the airstream. The characteristic smell or odour is likely to be removed by the introduction of the zeolite.

In order to ensure that there is very little energy consumption, the variable speed pumps will be used. There is going to be utilisation of the preventive maintenance of motors and other equipment. The lighting control gadgets will be installed. The worn-out pumps and motors are replaced by the best option. Having put those measures into consideration, some amount of energy saving will be realised.

Conclusion

The project intends to present some results concerning the practical experiment and approaches that are necessary in the water treatment plants. The results indicated that the mineral zeolite has a major role to play in treatment of water. The water that was made to pass through this mineral did not have the characteristic smell as for the case of the water that was not treated using the zeolite. The hardness of water was highly reduced and this made water soft and palatable. These advantages are very important to the economic production of water.

References

Joanne E. Drinan. (2012). Water and Joanne E. Drinan,Wastewater Treatment: A Guide for the Nonengineering Professional, Second Editio (4th ed.). London: CRC Press.

Rakness, K. L. (2011). Ozone in Drinking Water Treatment: Process Design, Operation, and Optimization (2nd ed.). Chicago: American Water Works Association.