Purification of water and sewage treatment

In this ppt contain detailed information about sewage treatment and purification of water.

1. PURIFICATION OF WATER AND SEWAGE TREATMENT BY M. SUBHASHREE 25PBI812 I - MSc. BIOCHEMISTRY

2. PURIFICATION OF WATER Water purification is the removal of contaminants from raw water to produce drinking water that's pure enough for human consumption or for industrial use. Many contaminants are removed to improve the water's taste, smell, and appearance. Small amounts of disinfectant are left intentionally at the end of the treatment process to reduce the risk of re-contamination in the distribution. It is not possible to tell the purity of water by visual appearance alone.

3. PURIFICATION CAN BE DONE BY TWO WAYS: NATURAL METHODS ARTIFICIAL METHODS

4. Aeration Sedimentation Sunlight Dilution Oxidation Plants & Animals (Aquatic) NATURAL METHODS

5. AERATION: Exposes water to air, removing dissolved gases and improving taste . SEDIMENTATION: Allows heavier particles to settle, clarifying the water. SUNLIGHT: UV rays disinfect by killing harmful microorganisms. DILUTION: Reduces contaminant concentration to safer levels. OXIDATION: Chemically breaks down impurities, aiding removal . PLANTS & ANIMALS: Natural filtration by aquatic life, improving water quality .

6. ARTIFICIAL METHODS Artificial methods may be carried out in two ways: A. Purification of Water on Small Scale B. Purification of Water on large Scale

7. A . Purification of Water on Small Scale BOILING: For 5-10 minutes, kills almost all organisms and removes temporary hardness. DISTILLATION: Not commonly used due to higher cost; used in labs, etc. Addition of Chemicals: BLEACHING POWDER : 5% solution is used. Dose: 3-6 drops/L; contact time of 1/2 hour. Chlorine Tablets/ Halazone Tablets. One tablet/ litre . IODINE SOLUTION: 02 drops of 2% Soln./ litre . KMnO4: An amount that gives just a pink coloration to the water. Alum: Used for turbid water in a dose of 0.1-0.4 grains/5 litres of water.

8. A.PURIFICATION OF WATER ON LARGE SCALE

9. SEWAGE TREATMENT

10. Sewage treatment is * the process of removing contaminants from wastewater and household sewage, both effluents and domestic. It includes “physical, chemical, and biological processes * to remove physical, chemical and biological contaminants. Its objective is to produce an environmentally safe fluid waste stream and a solid waste suitable for disposal or reuse . The objective of sewage treatment is to produce a disposable effluent without causing harm to the surrounding environment, and prevent pollution. INTRODUCTION

11. IMPORTANCE OF SEWAGE WATER TREATMENT PLANT It is very important to *provide some degree of treatment to wastewater before it can be used* in agricultural or landscape irrigation or for aquaculture. The principal objective of sewage treatment is generally to *allow human effluents to be disposed of without danger to human health or unacceptable damage to the natural environment*. According to research, * a large number of people die from water-borne diseases in most developing countries *. Therefore, it is very important to get the proper treatment of the water for a healthy living.

12. SOURCES OF WASTE WATER Human waste Washing water Rainfall collected on roofs, yards, hard-standings Domestic sources Direct ingress of river water Highway drainage Industrial waste

13. WASTE WATER TREATMENT PROCEDURE Sewage treatment generally involves three stages, called: Primary Treatment Secondary Treatment Tertiary Treatment

14. TYPES OF THE TREATMENT *Physical treatment* 2. Chemical treatment* *Biological treatment*