SEWAGE TREATMENT PLANT:
LET'S TOGETHER MAKE WATER SUSTAINABLE
Sewage is wastewater coming out from Residential Apartments, Tech Park, Hotels, Restaurant, Institutions, Shopping Centers, Recreational Places and many more which contains Kitchen waste, washing Cloths, faeces, urine, floor wash, Care wash and etc., Sewage treatment is a major problem in developing Countries due to water Scarcity.Sewage before disposed of either to surface water or on Land has to be treated, so as to make it free from pollution which contaminates our ENVIRONMENT and has dangerous impact on HUMAN HEALTH, LIFE and OTHER LIVING BEING. The Degree of treatment required depends upon the characteristics of Sewage and source of disposal.
Sewage can be treated in different ways. Treatment processes are classified as:
CONVENTIONAL ACTIVATED SLUDGE SEWAGE TREATMENT PLANT FLOW DIAGRAM:
- PRELIMINARY TREATMENT. The processes used are: SCREENING for removal of larger floating particles; GRIT CHAMBERS for removal of grit and sand; OIL AND GREASE TRAP for skimming of oils and greases.
- PRIMARY TREATMENT. It consists of SETTLING BASINS & MECHANICAL COAGULATION AND FLOCCULATION TANKS for removal of Suspended particles and colloidal Particles.
- SECONDARY TREATMENT. This is accomplished by biological treatment of effluent coming from the primary treatment tank. It Involves CONVENTIONAL ACTIVATED SLUDGE PROCESS (ASP), MOVING BED BIO REACTOR (MBBR), SEQUENTIAL BIO REACTOR (SBR) & MEMBRANE BIO REACTOR (MBR).
- THE FINAL OR TERTIARY TREATMENT. This treatment consists in removing taste, odor and organic load left after secondary treatment (killing of pathogenic Bacteria). It consists of PRESSURE SAND FILTER (PSF), DUAL MEDIA FILTER (DMF), and ACTIVATED CARBON FILTER (ACF) and DISINFECTION UNIT. This treatment consists in removing taste, odor and organic load left after secondary treatment (killing of pathogenic Bacteria). It consists of PRESSURE SAND FILTER (PSF), DUAL MEDIA FILTER (DMF), and ACTIVATED CARBON FILTER (ACF) and DISINFECTION UNIT.
Advantages of ASP
- Good quality effluent
- Loss of head is small
- Free from fly and odor nuisance high degree of treatment
Disadvantages of ASP
MOVING BED BIO REACTOR SEWAGE TREATMENT PLANT FLOW DIAGRAM:
- Not very flexible method
- Sludge disposal is required on large scale
- Skilled supervision is required to check that the returned sludge remains active
- More space requirement.
ADVANTAGES OF MBBR
- Capital Investment is low
- Responds to load fluctuations without operator intervention
- Lower sludge production
- Less area required
- Resilient to toxic shock
- Process performance independent of secondary clarifier
- No Sludge Handling Problem
- High effluent quality
- Operation & Maintenance cost is low
- Can treat large amount of sewage
- Cheaper construction
- Cheaper MOC
- Maintenance is easy.
DISADVANTGES OF MBBR
SEQUENTIAL BATCH REACTOR SEWAGE TREATMENT PLANT FLOW DIAGRAM:
- MBBR media tends to wash out of the systems over time
- Installation can be made for smaller capacities.
ADVANTAGES OF SBR
- Less land required.
- High effluent quality.
- All steps are contained in one tank
- Resistant against shock-loads and applicable for a large range of organic and hydraulic loading rates.
- Flexibility in operating conditions allows for optimizing different treatment objectives.
DISADVANTGES OF SBR
- Highly mechanized equipment (control panel).
- Effluent and sludge might require further treatment.
- Expense of providing aeration,
- Possible requirement for more than one treatment unit to accommodate cleaning schedules, and
- Requirement for monitoring and operating expertise to manage the reactor
- Sludge Handling Problem
- Operations and Maintenance cost is High.
EFFLUENT TREATMENT PLANT
Effluent treatment consists of a combination of physical, chemical, and biological processes and operations to remove solids, organic matter and, sometimes, nutrients from wastewater. Due to varying nature of the industrial wastes, many of the installations have designed their treatment units with due consideration to the raw waste characteristics and the effluent characteristics as established by Pollution Control Boards. Depending upon the mode of discharge or toxicity of some waste and the nature of the constituents present in it, the treatment may consist of any one or more of the following processes.
- Flow Equalization: Flow Equalization is used to minimize the variability of water and wastewater flow rates and composition
- Chemical Neutralization:Chemical Neutralization is the adjustment of pH to achieve the desired treatment objective.
- Physical Treatment: Physical methods of Effluent treatment accomplish removal of substances by use of naturally occurring forces, such as gravity, electrical attraction, and van der Waal forces, as well as by use of physical barriers.
- Chemical Treatment: Chemical treatment of wastewater focuses primarily on the separation of colloidal particles. This is achieved through the addition of chemicals (called coagulants and flocculants).
- Biological Treatment: The use of bacteria and other microorganisms to remove contaminants by assimilating them.
- Tertiary Treatment: Tertiary treatment is the advanced treatment process, following secondarytreatment of waste water that produces high quality water.
List of Major Industries in India are as follows:
General Flow diagram for Effluent Treatment Plant
- Textile Dyeing Industries
- Brewery & Winery Industries
- Service Station
- Laundry Industries
- Automobile Industries
- Pharmaceutical Industries
- Sugar Industries
- Paper and Pulp Industries
- Electroplating Industries