This document proposes developing affordable chemiresistive sensors to determine heavy metal concentration in water. Heavy metals like lead, nickel, copper, and chromium from industries have contaminated many rivers in India. The proposed solution is to use phenolic waste from other industries to create reusable, conductive films for chemiresistive sensors through laser ablation. The objectives are to develop a highly conductive microchannel sensor film and test its effectiveness in measuring heavy metals in water sources. The methodology involves collecting, purifying phenolic waste, synthesizing conductive films, laser ablation to create channels, and sensor testing. A budget and timeline of 3 years are provided.

1. Design of Chemiresistive Sensors to determine the
concentration of heavy metals in natural water bodies
SDG: Water & Sanitation
Siddharth Singh
21CHE230
Master in Chemical Engineering

2. Background
• Report of Central Water Commission, India 2019 mention the following data:
• The contaminated water when consumed leads to serious hematological and brain
damage, kidney malfunctioning.
• The sources of these heavy metals are mining, milling, plating and surface
finishing industries.
Contaminant Permissible Limit (μg/L) Number of Rivers
Lead (Pb) 10 69
Nickel 20 31
Copper 50 10
Chromium 50 22
Cadmium 3 24
Iron 300 142

3. Problem Statement
• “Development of affordable CHEMIRESISTIVE SENSORS for determining the
heavy metal concentration in natural water bodies”.
• CHEMIRESISTIVE SENSORS are costly and fabrication requires complex
arrangements.
• CHEMIRESISTIVE SENSORS based on phenolic films are not reusable.

4. Solution of the Problem
• Chemical, Pharmaceutical, Pulp & paper, wood products, non-metallic mineral
products sector, steel & metal, Petroleum refining industries excrete phenol in the
environment as waste in large quantities.
• This utilization of waste phenol can balance the high manufacturing cost of
sensors as well as valorization techniques can be utilized to recover phenol back
after each use.

5. Hypothesis
Phenolic
waste
Purification
Film
Synthesis
Laser
Ablation
Chemiresistive
Sensor

6. Objectives
• To develop a highly conductive micro channel engraved phenolic film-based
CHEMIRESISTIVE SENSOR.
• To check its promptness as a sensor for determining heavy metal concentration in
natural water bodies.
• Investigate methods to recover phenol & other chemicals and recycling them back
for next batch of CHEMIRESISTIVE SENSOR.

7. Deliverables
• A new approach including materials to developing Chemiresistive
sensors for inorganic and organic matter, and also biomolecules.
• A device that is efficient and scalable.
• Patents and publications

8. Methodologies Connected to objectives
• Collecting impure phenolic waste from target industries.
• Purification of phenolic waste for obtaining phenol at suitable purity.
• Set up of Experiment assembly including procurement of accessories.
• Synthesis of highly conductive rGO/phenolic films.
• Testing mechanical strength & improving over it.
• LASER ablation on film to create capillaries on the film.
• Testing the sensor for water bodies in different regions.

9. Gantt Chart, Milestones, Timeline
Activities Months
0-3 4-9 10-14 15-19 20-24 25-29 30-33 34-36
Literature Survey
Collecting phenolic waste
Experiment Assembly Set up &
Procurements
Purification of phenolic waste
Synthesis of highly conductive
phenolic films
Testing mechanical strength
LASER ablation
Testing the sensor for water bodies

10. Budget
Item Budget In Rupees
1st Year 2nd Year 3rd Year Total
A. Recurring
1. Salaries/wages 7,92,000 7,92,000 7,92,000 23,76,000
2. Consumables,
including analytical charges
6,00,000 6,00,000 6,00,000 18,00,000
3. Travel 50,000 50,000 50,000 1,50,000
4. Contingency costs 75,000 75,000 75,000 2,25,000
B. Equipment* 5,00,000 - - 5,00,000
Grand Total (A+B) 50,51,000
Overhead (maximum) 5,00,000
Support Request from Funding Agency 55,51000