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Rainwater Harvesting: A Potential Innovative Approach for Climate Resilient Water Resource Management in Textile Industry

for Water Conservation in Industrial Applications

Rainwater

Textile Processing

Water Saving

Shahoodah Anwar

PhD Scholar at College of Earth & Environmental Science

University of the Punjab

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PROJECT BACKGROUND & PROBLEM STATEMENT

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Water Scarcity Challenges

Global Water Challenge

Water scarcity is a global issue, especially in industrialized cities like Lahore, Pakistan

Groundwater Depletion

Excessive extraction of groundwater for industrial production has led to declining groundwater levels and water quality deterioration

Textile Industry Impact

High water consumption in textile processing: 100 liters for 1 kg of fabric

Innovative Solution: Rainwater Utilization

Significant Rainfall

Lahore region has considerable monsoon rainfall that remains untapped in industrial applications

Alternative Water Source

Rainwater can be utilized as a sustainable alternative to groundwater in textile processing

Multi-purpose Resource

Rainwater has dispersed, multi-use characteristics suitable for various industrial processes

Potential Benefits

  • Reduced groundwater extraction
  • Decreased water pollution
  • More sustainable textile processing

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RESEARCH OBJECTIVES

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This research aims to provide evidence-based assessment of using collected rainwater in textile printing and dyeing in Lahore, Pakistan

Rainwater Quality Characterization

Analysis of physical and chemical parameters

pH, conductivity, TDS, hardness, alkalinity

Turbidity, color, COD, ions, trace metals

Rainwater Usability Assessment

Evaluation of practicality in dyeing processes

Impact on dyeing results and quality

Optimization of rainwater usage parameters

Comparative Fabric Quality

Color difference (CIE Lab) analysis

Color fastness and K/S value comparison

Dye penetration, depth and intensity characteristics

Assessment against process water guidelines

Identification of treatment requirements if needed

Expected outcomes: Demonstration of rainwater's potential as a sustainable water source for textile processing with appropriate quality standards and treatment requirements

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METHODOLOGY: SAMPLING & LOCATION

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Project Location

Lahore, Pakistan

Industrial city with significant textile industry

Sampling Methodology

Sampling Periods

Monsoon Season

July 2023

Smog Season

January-February 2024

Sampling Method

Grab Sampling

Manual collection of water samples from collection tanks

Sample Analysis

Samples analyzed for physical and chemical parameters

Rainfall distribution in Pakistan (July 2023 vs Jan-Feb 2024)

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METHODOLOGY: WATER QUALITY ANALYSIS

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Standard Analysis Procedures

Water samples were analyzed using standard APHA methods to determine key water quality parameters.

pH Value

Method:APHA 4500H+ B

Measures acidity/alkalinity

Total Dissolved Solids

Method:APHA 2540 C

Measures dissolved solids

Total Suspended Solids

Method:APHA 2540 D

Measures suspended particles

Chemical Oxygen Demand

Method:APHA-5220

Assesses organic matter

Hardness

Method:APHA 2340 C

Measures calcium and magnesium ions

Sulfates & Chlorides

Methods:APHA-4500 SO42-E

Measures sulfate and chloride ions

Analysis Process

Sample Collection

Preparation

Analysis

Data Recording

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RESULTS: WATER QUALITY PARAMETERS

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Water Quality Analysis

Analysis of collected water samples from Lahore showed significant differences in key parameters.

Water Quality Parameter Comparison

Key Findings

pH Values

All within acceptable range (6.5-8.5)

TDS Levels

Monsoon rainwater (41 mg/l) has lower TDS than groundwater (268 mg/l)

Hardness

All below 500 mg/l standard

Implications for Textile Processing

Rainwater has potential for textile processing with appropriate treatment.

Sr. No.

Parameter

Units

PEQS

Groundwater

Monsoon Rainwater

Smog Rainwater

1

pH (25°C)

-

6.5–8.5

7.24

6.7

5.92

2

TDS

mg/L

<1000

200

41

102

3

TSS

mg/L

<200

Not Detected

Not Detected

11

4

COD

mg/L

<150

Not Detected

Not Detected

Not Detected

5

Hardness

mg/L

<500

140

20

50

6

Sulfate

mg/L

<600

67

11

25

7

Chlorine

mg/L

<1.0

BDL

BDL

BDL

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Methodology: Experimental Design

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Fabric Samples

  • 45 cotton knitted fabric samples
  • Weight: 190-200 g/m²
  • Material: Tubular single jersey fabric

Reactive Dyes

  • Three azo reactive dyes:
  • Synozol (yellow)
  • Sinarcian (red)
  • Novacron (blue)

Experimental Batches

Batch 1

Control Batch

Only Groundwater

Batch 2

Mixed Water

Groundwater + Rainwater

Batch 3

Rainwater Only

Only Rainwater

Water Types for Dyeing & Washing

Sample Type

Dyeing

Washing

Standard

Freshwater

Freshwater

Batch 1

Monsoon Rainwater

Freshwater

Batch 2

Monsoon Rainwater

Monsoon Rainwater

Batch 3

Foggy Season Rainwater

Freshwater

Batch 4

Foggy Season Rainwater

Foggy Season Rainwater

Experimental Purpose:To distinguish the role of rainwater in different process stages and evaluate its effectiveness as a water-saving alternative in textile processing.

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METHODOLOGY: DYEING & WASHING PROCESS

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Dyeing Process: Modified Isothermal Method

Dyeing Recipe Parameters:

Dye Shade: 1%, 3%, 5% (owf)

Temperature: 60°C

NaCl: 60 g/L

NaCO: 20 g/L

Liquor Ratio: 1:10

Dyeing Procedure:

1

Add 5g fabric sample and required dye (1%, 3%, or 5% owf) to 50ml water sample in a 500ml sealed stainless steel dyeing can

2

Heat from room temperature to 60°C gradually, maintain for 15 minutes

3

Add salt (NaCl) to promote dye penetration, continue dyeing for 15 minutes

4

Add sodium carbonate to make dye permanently attach to fabric, stop after 30 minutes

Washing Process

Washing Procedure:

Cold Rince

Room temperature for 10 minutes

Neutral Wash

In neutralizing water with 1-2 drops acetic acid to maintain pH 6.5-7.5

Warm Wash

At 50°C for 5 minutes

Hot Wash

At 80°C for 10 minutes

Soaping

At 95°C for 10 minutes with 2g/L non-ionic soap, liquor ratio 1:50

Final cold rince at room temperature for 5 minutes to complete the washing process

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RESULTS: COLOR ASSESSMENT & FABRIC QUALITY

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CIE Lab Color Difference Values

All samples were within the commercially acceptable tolerance range (DE*CMC < 1)

Dye & Depth

Lightness (DL*)

Hue Shift

Saturation (DC*)

DE*CMC

Blue 21 (1%)

Darker

Greener, bluer

Lower

Within limit

Blue 21 (3%)

Mixed

Greener, bluer

Lower to higher

Within limit

Blue 21 (5%)

Mixed

Redder, yellower

Higher

Within limit

Red 195 (1%)

Darker

Redder, yellower

Higher

Within limit

Red 195 (3%)

Mixed

Redder, yellower

Higher

Within limit

Red 195 (5%)

Brighter

Greener, yellower

Higher

Within limit

Key Findings

All samples showedcommercially acceptablecolor difference values

Subtle variations in lightness, hue, and saturation were observed

Rainwater as a dye vehicle showedpromising resultsfor color matching

K/S Values Analysis

K/S curves showed batch-to-batch variations in dye absorption:

Analysis

For Blue 21: Batch 4 showed deepest color at 5% owf

For Red 195: All batches showed higher K/S at 1% owf

For Yellow S3R: Batch 4 consistently had the lowest K/S values

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RESULTS: COLORFASTNESS PROPERTIES

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Colorfastness Test Results

All reactive dyes showed commercial acceptable colorfastness properties across different shade depths.

C.I. Reactive Blue 21

Washing Fastness:

Good to excellent (1%), Medium to excellent (3%, 5%)

Rubbing Fastness:

Medium to excellent

C.I. Reactive Red 195

Washing Fastness:

Very good to excellent (1%, 3%), Good to excellent (5%)

Rubbing Fastness:

Very good to excellent, medium at 5%

C.I. Reactive Yellow S3R

Washing Fastness:

Excellent to good (1%, 3%), Good to medium (5%)

Rubbing Fastness:

Similar trend, excellent to medium

Legend:

Excellent

Good

Medium

Fastness Properties Comparison

Figure: Comparison of dry crocking and wet crocking fastness properties for C.I. Reactive Yellow S3R

Key Findings

All dyes showed commercial acceptable fastness properties

Colorfastness generally decreased with increasing shade depth

Rubbing fastness showed similar trends to washing fastness

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CONCLUSIONS

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Key Findings

Feasibility Confirmed

Research confirms the feasibility of using rainwater in textile wet processing with acceptable results across all experimental batches

Batch Performance

Batch 1:Only monsoon rainwater (DE*CMC: 0.13-0.39)

Batch 2:Full process with monsoon rainwater (DE*CMC: 0.25-0.61)

Batch 3:Only smog season rainwater (DE*CMC: 0.15-0.41)

Batch 4:Full process with smog season rainwater (DE*CMC: 0.29-0.75)

Key Insight

Monsoon rainwater shows slightly better performance than smog season rainwater in textile processing

Color Difference Values (DE*CMC)

Summary of Conclusions

All batches showed acceptable color difference values (DE*CMC < 1)

Monsoon rainwater demonstrated slightly better performance than smog season rainwater

Rainwater can be effectively used in both dyeing and washing processes

Results meet commercial standards for textile products

Further research would explore rainwater utilization with appropriate storage and treatment technologies

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RECOMMENDATIONS & FUTURE DIRECTIONS

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While rainwater utilization shows promise, it cannot solve the water shortage problem alone

Daily Water Conservation

Shorten shower time

Fix water leaks

Recycle household water

Encourage public participation

Alternative Water Resources

Wastewater treatment

Seawater desalination

Greywater recycling

Diversify water sources

Policy & Innovation

Support sustainable water policies

Encourage tech innovation

Improve water resource management

Create enabling environment

Integrated Water Conservation Strategy

Implementation of these recommendations can create a comprehensive water conservation framework that addresses both immediate needs and long-term sustainability.