CONSTRUCTED WETLAND SYSTEM FOR

WASTEWATER

TREATMENT

AT KIT'S COLLEGE CAMPUS

WHY THIS PROJECT WORK?

Non – effective previous treatment

Strong, irritant & pungent odour to the water.

Same water was utilized for the gardening purpose.

Mosquito Breeding problem.

Disposed water of properties beyond acceptance limits.

Health & Sanitation problems to hostel residents.

CONCEPT OF CONSTRUCTED / ENGINEERED WETLANDS

•An artificial marsh or swamp field.

Treatment of anthropogenic discharge.

Artificial wastewater treatment systems rely upon natural microbial, biological, physical and chemical processes.

•Impervious clay or synthetic liners, and engineered structures to control the flow direction, liquid detention time and water level.

•Can treat urban runoff, municipal, industrial, agricultural and acid mine drainage.

Classification of Constructed Wetlands according to Macrophytes :-

•Free-floating macrophyte-based system •Rooted emergent macrophyte-based system •Submerged macrophyte-based system

Classification according to Flow Type :-

•Surface flow (SF) wetlands •Subsurface flow (SSF) wetlands: Horizontal flow constructed wetlands

General SFW Constructed Wetland Design

Sub Surface Flow Constructed Wetland for

Domestic Waste Treatment

Source : NEERI, Mumbai

Another typical SFW Constructed Wetland

Design

Design of Constructed Wetland in this case :

This system is Surface Flow (Horizontal Flow) type wetland & combination of floating, emergent & submerged type of vegetation.

Preliminary Treatment :

Already available raw sewage collection tank constructed in brick – cement.

Design of Various Zones :

Inlet Zone Design :-

This zone is meant for the application of floating vegetation.

This pond is designed for the detention time of

1 day.

The dimensions of the pond are

6.5 m x 5 m x 1.2m

Design of Various Zones :

Ephemeral Zone Design :-

This zone is meant for the application of emergent as well as floating vegetation. .

This pond is designed for the detention time of

1 day.

The dimensions of the pond are

8.5 m x 5 m x 0.9m

Design of Various Zones :

Wetland Zone Design :-

This zone is meant for the application of submerged as well as floating vegetation. This is the last pond from where the treated water can be pumped for any recycling purpose

This pond is designed for the detention time of

1 day.

The dimensions of the pond are

6 m x 5 m x 1.2 m

Design of Various Zones :

Project Execution

The project is executed considering all the factors affecting it:

Site Selection

Site clearance

Survey, Mapping for obtaining Ground Profile

Excavating according to design

Bund preparation, piping, lining.

Project Site : Before Execution

Layout Plan

Excavation using JCB

Excavated Site as per design

Ref. from Manual

Compaction & Bunding

Sheets spread over the pits to check percolation of water in soil

Lining : Plastic Sheets in 1st pond

Nominal Piping :-

Piping for conveying sewage are provided as following : Pipe conveying sewage to 1st Pond: 1 Nos – 9 inches dia. Pipe conveying sewage to 2nd Pond: 3 Nos - 4 inches dia Pipe conveying sewage to 3rd Pond: 1 Nos - 9inches dia.

Piping at First Bund : 3 No. 4” PVC

Piping at Second Bund :

1 No. 9” PVC

Piping Systems Provided

Selection of Plant Species :-

Selection of plant species is done depending on the previous study.

The new concept of using combination of all three types of plants is used.

The type of plants used are :

1) Floating type

2) Emergent type

3) Submerged type

Natural Aquatic System that can be used for treatment

Water Hyacinth :

(Echhornia crassipes)

This is a most common aquatic plant available abundantly in polluted water.

Famous for extracting Nitrogen from water.

Reproduces vegetative

Pistia sp.:

This is also common aquatic plant available abundantly in natural water bodies.

Famous for extracting Nitrogen & phosphorous from water.

Reproduces vegetative & faster than Water Hyacinth

Anabena azzola:

This is most common aquatic fern available abundantly in moderately polluted water bodies.

Famous for its symbiosis with nitrogen fixing bacteria .

Reproduces vegetative

But very difficult to withstand artificially created conditions.

Cat-Tail (Typha sp.):

This is very common emergent plant found in marsh places.

It is used here for the root zone treatment.

Reproduces sexually

Grows at relatively slow rate than floating plants.

Green Algae :

Found in most of the water bodies having sufficient solar penetration.

It is a submerged type of algae

Grows up to depth of 0.15 to 0.90 m

It is used here for increasing in the DO biologically. Reproduces asexually Grows at very faster rate.

Hydrilla :-

It is found in most of the water bodies having sufficient solar penetration.

It is used here for increasing in the DO biologically.

Grows at slower rate.

Requires very less toxicity to survive unlike other plants used here.

General Processes taking place in a Wetland

System

Phosphorus Transformation in Wetland Systems

Various floating plants used in Inlet Zone:

Echhornia crassipes, Anabena azzola, Pistia sp.

Various emergent plants used in Shallow Marsh Vegetation Zone:

Typha, Colocasia esculenta, Canna indica, Nymphaea pubescens

Chemical Analysis :-

Nitrogen (Ammonia) :

Spectrophotometer Method IS 2488 Part IV : 1974 (Performed at CETP lab)

TKN Phosphorous

Phosphates Dissolved Oxygen

BOD C. O. D.

Nitrogen (Ammonia) & Water Quality :-

1 Volume of Water will dissolve

1300 volumes of Ammonia.

Toxic Range of Nitrogen : Above 0.53 mg/L

Criteria :

The Nitrogen (Ammonia) in the water should not exceed 0.05 mg/L in order to protect aquatic organisms.

Parameter Avg. % removal Time Period Nitrogen (NH3)

TKN

Phosphates

BOD

COD

100 35 days

85.50 50 days

46.34 50 days

34 50 days

35.14 30 days

Results in Brief

Increase in D.O. Level :

The algal growth in abundance made it possible to dissolve higher amount of Oxygen in the water of 2nd Pond & onwards.

Period 6 days 12 days 24 days

Pond

Raw

1st

2nd

Nil Nil Nil

Nil

6.3 5.2

Nil Nil

4.3

Increase in DO can be judged by this colour difference in precipitate during the test.

Commissioning of the System:-

Activity Date

Site clearing 3rd December

7th January

19th January

Excavation with JCB

Dewatering from 1st pond

Tamping, consolidation & bund preparation

4th February

19th January

Collection of Emergent plants

Commissioning of the System :-

Water entered in 1st pond

Floating plants introduced in 1st pond

Collection of few other floating plants (Azzola & Pistia)

Activity Date

Laying of plastic sheets 5th February

15th February

17th February

20th February Analysis of effluent samples started for checking results

23th February

Plantation of Emergent plants 9th February

Economical Aspects :-

Total Cost of Project

Total Area under Project

Cost of Project per sq m area

Total Flow being treated

Total Cost per liter flow

Total cost per capita

Expected design period for pilot project

12996.00

225 sq m

57.76

40 m^3 /d

0.32

14.44

3 yrs (20-25 yrs)

1,08,000.00

2.70

:DSR 2008-09 by MJP

Summing UP :

1. Total Odor Removal

2. Considerable removal of TKN.

3. Considerable in Oxygen Level

4. Considerable reduction in Phosphates.

5. Cost Effectiveness

Summing UP :

4. A total solution system for college to treat wastewater.

5. A working model for the future students to pursue further study & research in this area.

6. A value addition to Institute’s policy to take initiative in any innovative ideas like ‘Energy Park’

7. The project has special contribution to the ecosystem development at the site.

Summing UP :

Some Practical Problems & Possible Remedies :-

1. Stagnancy of Water

2. Limitations of Lining Material

3. Lack of continuous sludge removal system.

4. Waste specific behaviour of plants.

5. Limitation of time

Waste Specific Behaviour of Echhornia crassipes

Summing UP :

Future Scope :-

1. Maintenance of the system in future is required.

2. More study about the efficiency & process of the system is required to be done by future students.

3. Even this project can be an ideal system for the research as well as application point of view to many communities, institutes.

THANK YOU!

SUBMITTED & PRESENTED BY

HARSHAD VIJAY KULKARNI

VISHAL S. CHOUGALE NIKHIL N. SHETYE

SANTOSH E. SHIRKE DIPTI S. SHINDE

UNDER THE GUIDANCE OF

PROF. S. S. SHAHA

DEPARTMENT OF ENVIRONMENTAL ENGINEERING

KIT’s COLLEGE OF ENGINEERING, KOLHAPUR