For Waste Water Treatment Presented By Sandeep B Koushik G

Sub Surface ConstructedWet Lands

Due to Rapid Industrialization

AndUrbanization

• Sanitary sewage• Commercial wastes• Surface runoff• Agricultural wastes• Industrial effluents

Various types of Waste Waters

Effects Of These Waste Water• Decaying organic matter and debris can use

up the dissolved oxygen.• In a lake so fish and other aquatic biota

cannot survive excessive nutrients, such as phosphorus and nitrogen (including ammonia), can cause eutrophication.

• Bacteria, viruses and disease-causing pathogens can pollute beaches and contaminate shellfish populations.

• Leading to, cadmium, chromium and arsenic can have acute and chronic toxic effects on species.

Sub Surface ConstructedWet Lands

ForWaste Water Treatment

What is Wet Land?• A constructed wetland or wet

park is an artificial wetland, marsh or swamp created as a new or restored habitat for native and migratory wildlife, for

anthropogenic discharge such as • Wastewater• Storm water runoff• Sewage treatment• Land reclamation after mining,

refineries,

Classification of Wet LandsConstructed wetlands are classified according to the water flow regime • Free water surface flow (FWS CWs) or• Subsurface flow CWs.Based on the flow of water in the SF CWs. They are again classified into • Horizontal Flow Beds (HFB)• Vertical Flow Beds (VFB)

Free Surface CW

Horizontal Surface CW

Vertical Surface CW

Horizontal Flow Bed

Inlet

HFB HFB near Portugal Outlet

Design Specifications• The depth of filter beds is normally around 60 cm with an

additional 15 cm freeboard for water accumulation.• The required specific surface area is about 3-10 m²/p.e. depending on temperature and other factors.• The organic loading per surface area should not exceed 4-10 g BOD/ (m²) in cold climates 16 g COD/ (m²) in warm climates.• The hydraulic loading should be 60-80 mm/d for

grey water and 40 mm/d for wastewater.

Vertical Flow Bed

Inlet

Outlet

Vertical Flow Beds

Design Specifications

• The depth of the sand filter beds should be at least 50 cm, with an additional 20 cm of gravel at the base to cover the drainage pipes.

• The required specific surface area is usually 3-4 m²/p.e. in cold regions.• The organic loading per surface area should be

limited to 20 gCOD / (m²·d) in cold climates).

Pre TreatmentPre-treatment removes materials that can be easily collected from the raw waste water before they damage or clog the pumps.• Screening• Grit Removal

Primary Treatment:• In the primary sedimentation stage, sewage flows through large tanks,

commonly called "pre-settling basins", "primary sedimentation tanks" or "primary clarifiers”.

• The dimensions of the tank should be designed to effect removal of a high percentage of the floatables and sludge.

• A typical sedimentation tank may remove from 50 to 70 percent of suspended solids.• 30 to 35 percent of biochemical oxygen demand (BOD) from the sewage.

• Vegetation in a wetland provides a substrate (roots, stems, and leaves) upon which micro organisms can grow as they break down organic materials.

• This community of microorganisms is known as the periphyton. The periphyton and natural chemical processes are responsible for approximately 90 percent of pollutant removal and waste breakdown.

Bio Filtration

Plants Chosen:• MacropytesThey produce oxygen, and act as food for some fish and wildlife.• Although the majority of constructed wetland designers have long relied principally on Typhas and Phragmites.

Eichhornia crassipes

General Contaminants Removal:• Physical, chemical, and biological processes combine in wetlands to

remove contaminants from wastewater.• Theoretically, wastewater treatment within a constructed wetland

occurs as it passes through the wetland medium and the plant’s rhizosphere.

• Rhizosphere is a thin film around each root hair is aerobic due to the leakage of oxygen from the rhizomes, roots, and rootlets.

Specific Contaminants Removal:• Nitrogen Removal :The biological transformation of organically combined nitrogen to ammonium nitrogen during organic matter degradation by ammonifaction process.• Ammonia removal :The formation of ammonia (NH3) occurs via the mineralization or ammonification of organic matter under either anaerobic or aerobic conditions.

This ion forms when ammonia combines with water as follows:

Ammonifiaction:NH3 + H2O (NH4+) + OH −⇌

The Nitrite is oxidized to nitrate (NO). The overall nitrification reactions are as follows:Nitrification:(1) 2(NH4+) + 3O2 4H+ + 2H2O + 2NO⇌(2) 2NO + O2 2NO⇌

Phosphorus Removal:It occurs naturally in both organic and inorganic forms.1. The binding of phosphorus in organic matter as a result of incorporation into living biomass,2. Precipitation of insoluble phosphates with ferric iron, calcium, and aluminum found in wetland soils.

BOD and COD removal:• Bio Oxygen Demand (96.2 % removal)• Chemical Oxygen Demand (93.8% removal)

Applications:1. Municipal wastewater treatment2. Treatment of household wastewater or grey water3. Tertiary treatment of effluents from conventional wastewater treatment plants4. Industrial wastewater treatment such as landfill leachate, petroleum refinery wastes, acid mine drainage, agricultural wastes, effluent from pulp and paper mills, textile mills.5. Sludge dewatering and mineralization of fecal sludge or sludge from settling tanks.6. Storm water treatment and temporary storage7. Treatment of water from swimming pools without chlorine.

Stop Pollution

Think Solution Bring Revolution

Thank You