INTRODUCTION

Water is essential for the survival of life on earth. Due to environmental degradation and poor sanitary surroundings, water supply sources get polluted with harmful micro-organisms. 80% of infectious disease are water born and 50% of death among children is due to diarrhoeal diseases in developing countries.

• This method is –

1. Cost effectives
2. Less time consuming
3. Requires less expertise
4. User friendly water quality field testing kit.
5. It can be uses in distant region like slum, Rural areas.

WHAT IS H2S STRIP TEST

• H2S test performs to check the microbial contamination in water.
• It is quick and qualitative test to determine the coliforms which present in drinking water they causes disease like Diarrhoea, Typhoid.
• These bacteria belong to family Of Enterobacteriaceae.
• Most of the Member species of Enterobacteriaceae are sulphate reducing bacteria. They use sulphate As a terminal electron acceptor for degradation of Organic Compound and produce H2s gas.
• H2S gas was one of the earliest products of bacterial decomposition of organic compound.

Primary work done by Vigyan Ashram fellow Shubham Barmukh

http://vadic.vigyanashram.blog/2021/06/30/h2s-kit-preparation/

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Problem known in existing kit

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Trials on existing H2S strips

Taking 25 bottles of current kit and in three steps get trials on different water samples to study for working result.

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( Date – 21/07/2021 )

OBSERVATION :-

sr.no	Sample name	Untreated UV water	UV treated water with 5 mins	UV treated water with 10 mins
1	Kitchen water	Positive  (38 hrs)	negative (48 hrs)	negative (48 hrs)
2	Dream House	Positive  (48 hrs)	negative (48 hrs)	negative (48 hrs)
3	Distilled water	Positive  (38 hrs)	Positive  (48 hrs)	negative (48 hrs)
4	RO water	negative (48 hrs)	Positive  (48 hrs)	negative (48 hrs)
5	Tap water	Positive  (38 hrs)	Positive  (48 hrs)	negative (48 hrs)

As per observation each sample takes different time gap

OBSERVATION TABLE :-

Sr.No	Sample Name	Results ( Normal Water) After 48 hrs.
1	Kitchen Water	Positive
2	Distilled Water	Positive
3	Dream House	Positive
4	Tap water	Positive
5	UV filter	Negative

As per observation distilled water shows test positive

OBSERVATION TABLE

sr.no.	sample name	Result	Time
1	UV water	negative	48 hrs
2	distilled water	negative	48 hrs
3	Dream house	positive	36 hrs

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Problem defined in existing project according to observation

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First step for H2S water testing kit

Need of project

To developed robustness of kit and make it commercially viable

TASK (11/08/2021)

Testing of different type of paper for the kit

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Observation Table :-

we need to find water holding capacity of the paper select the paper type of the strip. (Date-13/08/2021)

Observation tables are given Below.

• As per observation Tissue paper get more shrink after absorb media and hard to dry and fold it.
• Whatman filter paper no.41 is easy to fold and it absorbs sufficient media
• Water hyacinth paper is heavy in initial weight that’s why it will be never use for for strip
• Filter paper HM 2 absorb 1 ml media it also good for try.

conclusions of paper selection :-

• As per observation Whatman Filter paper No.- 41 and Filter paper HM 2 is used for trials

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Media preparation for strip

Chemicals to prepared H2S water testing bottles :- ( Date- 14/08/2021)

Bacteriological Grade peptone	4 g
Dipotassium Hydrogen phosphate (K2HPo4)	0.30 g
Ferric Ammonium Citrate ( C6H8FeNO7)	0.15 g
Sodium Thiosulphate (Na2S2O3)	0.2 g
Teepol ( neutral PH)	0.025 ml
Distilled Water	20 m

Media pH is should be between 6.5 to 7.2

References

http://pacificwater.org/_resources/article/files/H2S.pdf

Different strip paper trials with using media ( Date- 15/08/2021)

1. Tissue Paper
2. Whatman filter paper no. 41
3. Filter paper HM 2

Conclusion :– As per observation Whatman filter paper no. 41 and Filter paper HM 2 is better for trials on H2S kit

Preparation of strips (Date – 17/08/2021)

Drying process of strips (17/08/2021)

Sterile Processes of plastic H2S bottles ( Date-19/08/2021)

Strips trials by using above media

Procedure ( 21/08/2021)

• Take 10 H2S water testing bottles and 5 bottles for each strip
  • Whatman filter paper No. 41
  • Filter paper HM 2
• Get 4 different water samples in both strips bottles
  • Distilled water
  • Vigyan Ashram Dream House water
  • Tap Water
  • Vigyan Ashram Kitchen water
• Filled the water sample up to the mark
• Incubate at room temperature for 48 hrs. and wait for results
• Note down the result

Observation – ( Whatman filter paper No. 41 )

Sr.No	Sample Name	Results ( Normal Water) After 48 hrs.
1	Kitchen Water	Positive
2	Distilled Water	Positive
3	Dream House	Negative
4	Tap water	Positive

Observation – (  Filter paper HM 2 )

Sr.No	Sample Name	Results ( Normal Water) After 48 hrs.
1	Kitchen Water	Positive
2	Distilled Water	Negative
3	Dream House	Positive
4	Tap water	Positive

observation

• Results are not get proper it shows positive results in Distilled water.
• Test still consume time to show results

Conclusion

• Need to modified H2S kit Media
• pH should be maintain.

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Task – 2

• To overcome to this difficulty we modified composition of the media.
• H2S medium was modified by adding L-cysteine HCl

Media Preparation for the strip

• Prepare Media for 50 ml
• Each 24.375 gm. powder media are given below

Name of chemicals	Qty. in gm / ml
Bacteriological Grade peptone	20
Dipotassium Hydrogen Phosphate	1.5
Ferric Ammonium citrate	0.75
Sodium Thiosulphate	1.0
L-Cysteine HCl	0.125
Teepol ( neutral pH)	1.0 ml

• The powder media is completely soluble in water.
• Dark Amber colour solution is formed in the flask on addition of water.
• L-Cysteine HCl
• The pH of aqueous solution with distilled water shall be between 6.5 to 7.2

AIM

Compare Vigyan Ashram H2S kit results with the standard H2S kit results.

PROCEDURE

• Take 10 bottles of H2S water testing kit
  1. Vigyan Ashram H2S kit – 5 bottles
  2. Standard H2S kit – 5 bottles
• Get 5 different water samples in both comparing bottles.
  • Vigyan Ashram Kitchen Water
  • Vigyan Ashram Dream House water
  • Boil at 50 degree Celsius and wait for 2 hrs.
  • Boil at 70 degree Celsius and wait for 1 hrs.
  • Boil at 80 degree Celsius and wait for 2 hrs.
• Filled the water sample up to the mark
• Incubate at room temperature for 48 hrs. and wait for results
• Note down the result

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Observation Table

sample Name	Vigyan Ashram	Time (hrs.)	Standard kit	Time (hrs.)
Vigyan Ashram Kitchen Water	Positive	24 hrs.	Positive	36 hrs.
Vigyan Ashram Dream House water	Positive	30 hrs.	Positive	32 hrs.
Maintain at 50 degree Celsius for 2 hrs.	Negative	–	Negative	–
Maintain at 70 degree Celsius for 1 hrs.	Negative	–	Negative	–
Maintain at 80 degree Celsius for 2 hrs.	Negative	–	Negative	–

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Conclusion

• Vigyan Ashram testing kit results are matched with standard testing kit.

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Second Trial

Getting more Trials on same kit by using different water samples and it compare with standard testing kit.

PROCEDURE

• Take 6 bottles of H2S Water testing kit
  • Vigyan Ashram H2S kit – 3 Bottles
  • Standard H2S kit- 3 Bottles
• Get 3 different water samples in both comparing bottles.
  • RO Water
  • Vigyan Ashram Boys hostel water
  • Distilled Water
• Filled the water sample up to the mark
• Incubate at room temperature for 48 hrs. and wait for results
• Note down the result

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Observation Table

sample Name	Vigyan Ashram	Time (hrs.)	Standard kit	Time (hrs.)
RO Water	Positive ( slightly black)	36 hrs.	Positive ( slightly black)	36 hrs.
Vigyan Ashram Boys hostel water	Positive	24 hrs.	Positive	30 hrs.
Distilled Water	Negative	–	Negative	–

Conclusion

• Vigyan Ashram testing kit results are matched with standard testing kit
• Results of our kit were observed faster than the standard kit.

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Task-3

Objective

To check the life-span of H2S water testing kit

Preparation for the task

• Prepared 100 ml H2S Strip Media
• Make 100 strips Coated with H2S Media
• prepared 100 bottles
• cover all the bottles with plastic wrap.

Water sample

• For checking life-span of strip used in modified H2S bottle i will use 1000 ml VA kitchen water for 2 month.
• At testing time use same water sample and treat that water under UV for 15 mins.

Continuous Data Monitoring Sheet

• To check the life-span of H2S water testing kit, we are scheduled plan of getting trials on different day.

Waiting for results………