best practice in sewage & effluent treatment technologies

Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare

Best Practice in Sewage & Effluent Treatment Technologies


Objectives Understand basics of earth’s ecological system Understand factors that influence ecology Appreciate influence of wastewater on ecosystem Understand water-cycle leading to wastewater generation Achieve familiarity with worldwide concerns on issue of

wastewater management Understand nature of regulations imposed to monitor and

control wastewater disposal Understand the planning considerations related to

wastewater


Objectives continued..

Understand about the sources responsible for origins of wastewater

Understand the types of wastewater/sewage systems Understand various methods about the estimation of

wastewater quantity Understand the method of hydraulic design of sewers Understand the basics of operation & management of

sewer networks Appreciate the selection of material for sewer construction


Ecology• Science of relationship of all elements of ecosystem

• Crucial elements– Air– Water– Living being– Vegetation


Water - Effect on Ecology

• As important as air

• Necessary for survival of plants & living beings

• Quality deterioration makes less available for productive use

• Reduction in availability of good quality brings ecological imbalances and threatens survival of user


Wastewater Generation• Due to disposal of excreta

• Washing & cleaning

• Industrial applications

• Commercial applications

• Rainfall - pesticides, fertilisers

Source: http://inweh.unu.edu/wastewater-reuse-infographic/


Wastewater - Contaminants

• Solids– Floating & suspended– Dissolved

• Liquids– Chemicals

• Gases– Ammonia– Methane

• Micro-organism

Source: http://www.nytimes.com/2010/02/10/world/asia/10pollute.html?_r=0


Regulatory Focus • Initially -

– On immediate environmental concerns– Control on suspended solids & organic matter

• Intermediate -– On treatment pertaining to dissolved nutrients like

• Current -– Control over long term effect of certain substances


Project Financing

• Capital cost– Investigation– Land acquisition– Engineering & construction

• Operational cost– Energy cost– Manpower cost– Consumable cost– Repairs & spare parts


Wastewater System

• Collection– Interception and transportation of wastewater

• Treatment– Process to bring harmful contents within acceptable

limits

• Disposal– Discharge of effluent to land or water body


Sewer Layout


Factors Affecting Layout

– Topographical features of the locality

– Extent of catchment area

– Hydrological features

– Location of disposal points

– Quality of wastewater at point of treatment

– Type of interception and carriage system adopted


Radial Sewer Pattern

– Fig 2.02


Perpendicular Sewer Pattern


Interceptor Sewer Pattern


Zone Sewer Pattern

– Fig 2.05


Fanlike Sewer Pattern

– Fig 2.06


Peak to Average Flow

Population Served Peak to AverageFlow Ratio

Up to 10,000 3.5 : 110,000 to 25,000 3 : 125,000 to 50,000 2.5 : 150,000 to 500,000 2 : 1

Above 500,000 1.5 : 1 to 1.75 : 1


Wastewater Hourly Variation


Flow Velocity in Sewer

• Limiting conditions for velocity– Should not be so low that solid particles separate

from wastewater and settle in the sewer– Should not be so high that solid particles of

wastewater be able to weather the material for sewer construction


Maximum Flow Velocity

For different sewer materials, value of maximum velocity is as below -

Material of Sewer Limiting Velocity

Cast Iron 3.5 to 4.5 m/sec

Stoneware 3.0 to 4.0 m/sec

Cement Concrete 2.5 to 3.0 m/sec

Glazed Tiles 4.5 to 5.5 m/sec

Bricks 1.5 to 2.5 m/sec

Earth 0.6 to 1.3 m/sec


Flow Characteristics – Partially Filled Circular Sewer


DO YOU WANT TO KNOW MORE?

If you are interested in further training or information, please visit:

http://idc-online.com/slideshare