Effluent Treat Plant (ETP) Basic Working module

Effluent Treat Plant (ETP) Basic Working module

Effluent Treat Plant (ETP) is mainly used for treating waste water which is extracted from Dyeing or Washing factories. 

ETP is mainly divided in Three different functions:

1) Physical

2) Chemical

3) Biological

- In the above three functions, Chemical and Biological is mainly highlighted functions where water is treated in different stages/ filtration processes.

Blog Diagram of an ETP :-

[Note : Copy and Save the image & zoom in to see the texts inside the picture]

CHEMICAL ETP PLANT TREATMENT STAGES :-

1)  Screening Unit : All the visible and seen particles are filtered in this unit using Net type filter which is called Screening PIT.

2)  Equalization Tank : Here is the Homogenization Mixture is made after taking all the water from Washing Units, Dyeing Units, PP Spray Chamber Units, and also Sample sections waste water. In short, All the untreated water is collected in this tank for further procedure.

3) Chemical Dozing Tank : Here the chemicals are dozed step wise. Please see my picture above. There are PH adjustment , PAC dozing & Polymer dozing Units where this three different tasks are done. PH adjustment tank is for checking the PH of untreated water for balancing the PH to 7.0. And PAC dozing tank is used for Poly Aluminum Chlorite dozing, and Further thank is used for Polymer dozing. After this three chemical dozing thank , the water passes through the Sedimentation Tank where the Sludge are thicken and goes down.

3) Sedimentation Tank : In this tank the sludge are thicken and goes down because of previous chemical dozing. And from here the water passes through BIOLOGICAL TANK.

4) Sludge Thicker Tank : From sedimentation the deposited sludge are taken to Sludge Thicker Tank where -in portion : 60% Water and 40% Sludge comes from Sedimentation Tank. The Sludge is thicken in the downer portion of this Tank and then it is sent to Filter Press using submersible pump. The rest 60% Water is again sent to Equalization Tank for re treatment cycle wise.

5) Filter Press : All the sludge from Sludge Thicker Tank is drawn to filter press and in this press the sludge is pressed at high pressure and drained to 50-100 kg Jute / Plastic Bag and kept a certain time below sunlight or for drying the sludge for disposal.

Chemical Description:

a) PH Adjustment Tank : If the PH is higher then Acid is used to lower the PH level and if the PH is lower then Alkali is used to control the PH level. In short, the PH adjustment tank is used to control PH level- 7.0. In dyeing and washing factories , Salt, soda- caustic and other chemicals are uses which is mostly alkali and in that case most of the times PH is higher than 7.0 and acid is generally used to pull down the PH level but if the PH level is lower then alkali like caustic is used to pull up PH level.

b) PAC : Poly Aluminum Chlorite (PAC) , it is used for clearing the color of water. Generally textile waste water is - dark blue type color for washing factories, and in dyeing factories though the color varies but most of the times its dark or black. PAC - is kind of FITKARI which makes the color clear after applying in water.

c) Polymer : Polymer is used to control the sludge thickening. The waste water has many chemicals , dye stuff, micron smithereens cotton, etc. Polymer thickens those particles from the water to the downer portion of Sedimentation tank.

d) Water DE-coloring : If the water color is mostly dull and not improving then the water DE-coloring agent is used after sedimentation tank treatment. But if Polymer and De-coloring is used together then Polymer do not gives efficient work and in that case Polymer dozing needs to be increased gradually.

BIOLOGICAL ETP PLANT TREATMENT STAGES :-

1) Biological Tank 1 : Water is drawn from Chemical Sedimentation tank to Biological Tank 1 - for further treatment. Here - Air is passed through the water and the water is kept for a certain time in this tank to grow the Bacteria in the water. Here : Temperature is kept : 35-37 degree Celsius and PH is kept : 7-8 , Besides this the Air is applied to increase the DO level. DO means: Dissolved Oxygen in the water. The DO is kept- 4ppm. In the biological tank : Urea Fertilizer 60% & Phosphoric Acid/DAP 40% is applied to grow the bacteria level. (DAP- Di-Ammonium Phosphate)

2) Biological Tank 2 : BIOLOGICAL TANK-2  repeats the process of Biological tank-1.

3) Biological Sedimentation Basin : After treatment in the Biological Tank treated water is passed to Biological Sedimentation Basin where Step wise Anti-foaming agent is applied to control the extracted water foaming level. and Also in this basin some amount of sludge thicken in the downer portion of the Tank and 20% this amount of sludge is pulled up & applied to biological tanks cycle wise using pump , & rest 80% is passed through the sludge Thickener tank which is adjacent to Chemical ETP. Here, 20% of Sludge is applied in the Biological tank because those sludge is the main impactor of Bacteria rapid growth.

4)  Discharge Tank : This tank is only used to check the final stage water property. and If the coliform level is higher then 0.3ppm sodium hypochlorite is dozed to kill the bacteria to minimum the Coliform level.

 Chemical Description:

In the biological tank Urea Fertilizer and Phosphoric Acid/ DAP is applied to grow the Bacteria Level. Actually, Urea is used for - Nitrogen,  & DAP/ Phosphoric Acid is used for - Phosphorus and both are controller of Bacteria growth. Nitrogen + Phosphorus helps the Bacteria to grow rapidly.
(DAP- Di-Ammonium Phosphate)

Why Bacteria needs to grow?

 After chemical treatment, the water is 50% treated and controlled but while garments dyeing/ washing various different type chemicals are used in the washing/dyeing machines/bath which creates bonds in water and which is not properly removed from the water after chemical water treatment. That is why, in the water the Bacteria level needs to be grown which will break all the chemical bonds remaining in the water.
- Urea + DAP helps to grow the bacteria, but it does not birth Bacteria, Bacteria is automatically grown in the water due to Sludge, and other property. and Fine Bubble +  Urea + DAP helps those bacteria to grow rapidly and to break the chemical bonds and purify the water finally.

DO Level :- 
Aeration helps to increase the DO level of the Water. If the DO level is not sufficient then Bacteria or other living organ will not be able to live in the water. That is why DO level is very important to maintain.

CHEMICAL DOZING SUMMERY :-

Chemical ETP :
1) Poly Aluminium Chlorite (PAC) AL2CL(OH)5
2) Polymar (Poly electrolyte) : Sludge Coagulation
3) Water De-colorent : Water color controling
4) PH controlling: Alkali/ Acid

Biological ETP :
1) Urea Fertilizer
2) Phosphoric Acid/ Diamonium Phosphate
3) Anti-foaming agent
4) 0.3ppm sodium hypocholoraite to kill bacteria

BASIC REQUIREMENT TESTING PARAMETER SUMMERY :-

Chemical ETP:
1) Chemical Dozing Tank: BOD, COD, PH
2) Color Visual + Decolorent agent dozing if necessary

Biological ETP:
1) Biological Tank Inlet: BOD, COD
2) Biological Tank 1 : Temperature, DO, PH
3) Biological Tank 2 : Temperature, DO, PH
4) Discharge Tank : BOD, COD, COLOR, PH, DO, Foaming Visual check, Coliform check, etc.

CHEMICAL MIXING :
1) Lime : (800-1000 ppm) to correct PH up to : 7-8
2) Alum/PAC : (200-300ppm) to clear the water color.
3) Poly electrolyte (0.2ppm) : To settle the suspend matter & reduce SS/TSS.

Chemical Application & Identification Necessary quantity:
At first, 1 Liter of untreated water need to be taken, then drop wise diluted chemical need to be applied in the untreated water from the previously prepared Chemical Stock solution of 10%, 20. After then , Untreated water is kept for 5 minutes to see the result and then checked the visual impression of the water. This way required chemical quantity identified.

(Note: All the treatment process is customized as per Buyer water testing requirements. like- if buyer requirement is water TSS below 150 then less treatment is necessary elsewhere if the buyer requirement TSS is below 30 then much longer treatment is necessary in that case.

Thanks for reading,

Blog Written by,
K M Zahidur Rahman
Executive R&D - Ha-Meem Group

Development using laser machine and some technical discussion about laser

Laser Machine : 

লেজার একটি আক্ষরিক নাম। ইংরেজি অক্ষর LASER এর L হল Light, A হল Amplification, S হল Stimulated, E হল Emission, R হল Radiation; LASER এর পূর্ণ শব্দটি হল Light Amplification by Stimulated Emission Radiation. অর্থাৎ উত্তেজিত বিকিরণের সাহায্যে আলোক বিবর্ধন। সাধারন আলোতে বিভিন্ন মাপের তরঙ্গ থাকে। একই বর্ণের আলোতে একই মাপের তরঙ্গ থাকলেও তারা বিভিন্ন তলে চলে। কিন্ত লেজারে সব তরঙ্গই হয় একই মাপের এবং তারা চলে একই তলে অর্থাৎ লেজার রশ্মি সংসক্ত। এ রশ্মি অত্যন্ত ঘন সংবদ্ধ একমুখী বলে তা অনেক পথ অতিক্রম করতে পারে এবং এরা মাত্র কয়েক মাইক্রন (১ মাইক্রন = ১০-৩ মি. মি.) চওড়া। এজন্য এতে প্রচণ্ড তাপশক্তি সঞ্চার করা সম্ভব হয় এবং তাপমাত্রা সূর্যের ওপরকার তাপমাত্রাও বেশি হয়। ফলে লেজার রশ্মি দিয়ে মানুষের একটা চুলকেও ছিদ্র করা সম্ভব।

 Sample picture of Laser Machine.


Laser Machine is generally used in denim washing factories for Whisker making , Handsand/Sandblasting, All over printing, drilling, and for many other reasons.


The main machine functions/ Particles of a laser machine :

  
1) AC line to DC line converting Power supply module
2) Frequency Generation module for laser burner which is passed through capacitor to burner chamber
3) CO2 gas using Fire / Burner module (laser light making chamber)
4) Laser light emitting survey motor & mirror used module for controlling the laser light how it will be fallen on the surface.
5) The computer , which is used to feed the design which will be printed on the fabric.

This above particles are the basic function of a laser machine which is a complete laser machine. 

 

LASER FIRE BURNING CHAMBER

  

LASER FIRE BURNING CHAMBER

 

FREQUENCY MODULE (Left) AND BURNER IMAGE TOGETHER (right)

 

FREQUENCY MODULE TOP VIEW

 

FIRE CHAMBER TO EMITTER - CARRIER PIPE USING MIRROR

 

FIRE CHAMBER TO EMITTER - CARRIER PIPE 

 

EMITTER OF LASER

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SOME IMAGE WHEN LASER PRINTING ON DENIM FABRIC 

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SOME IMAGES OF ALL OVER PRINT (BEFORE WASH PROCESS)

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SOME IMAGES ON ALL OVER PRINT GARMENTS (AFTER WASH) 

The above garments are my developed using our company laser machine.

The art work of those denim wash garments as below:

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THANKS FOR READING!!

BEST REGARDS,

K M ZAHIDUR RAHMAN
 

Different tone appearance in denim wash for different chemical application

   Thanks for Reading,

Executive - R&D
Ha-Meem Group

Denim Finishing : Vacume/Air pressed Balloon type HandSanding dummy replacement with Pillow type machanical dummy

Today I am going to discuss about the problem and the facility of vacuum/air pressed balloon type denim hand sanding stand & its replacement.

Usually hand sanding is necessary for giving the used look to the denim and also it brings the abrasion as well.

To spray Potassium Permanganate it also needs to HandSand to the certain position where PP will be sprayed.

To protect the garments from Lycra damage issue of the denim fabric now a days pillow type sanding dummies are used which is shown in the below image.

This type of Pillow type dummy is less harmful to garments body than the air pressed balloon type dummy.

But the problem of this dummy is crease mark arising. As the garments are placed loosely on the pillow, fabric with polyester+spandex is very tough to do handsanding on this pillow because the garments fabric wrinkly while hand sanding on the pillow and it cause the crease mark. 


(writing is not complete...to be continued later...............................)

Warp and Weft of Denim fabric

Most of the people are always confused about the warp and weft of denim fabric/Pant.
The below image is for them, Please keep this picture in your phone and get to know anytime without confusion-

Thanks and Best regards,

Sincerely
K M Zahidur Rahman

Powder Bleach dilution Machine

Today , I have myself designed and drawn a powder bleaching dilution machine for our factory. It is vary essential for mainly washing factory which needs diluted bleach daily.

Below is the drawing of bleach dilution machine :-

For bleach dilution-
1) The drum where bleach will be diluted it must be plastic made and also it should have good thickness because while diluting powder bleach in water it releases enough heat. In that case, Pro type plastic water tank may be used. (one thing must remember, Drum height should be more than wideness).
2) All other frame should be coated with plastic/ PVC due to making safe from bleach.
3) The water follow meter should be ultrasonic wave water follow meter so that each of the liter of water can be calculated correctly (like- petrol pump uses)
4) Bleach draining valve must be PVC or plastic made otherwise bleach will make the valve spoiled sooner.
5) Bleaching dilution inner shaft should have two bold node for sent up the water revolving. one in the bottom edge and another in the middle of the shaft.(more nodes can be also used, depends on the drum wideness)
6) Shaft should be placed straightly to the bottom otherwise it will jerk and make problem at the time of dilution.

This is the basic diagram,
You may redesign yourself as per your necessity.


### Images of complete Machine_\

 Calcium Hypochlorite Ca(ClO)2 is produced from -

-this reaction, where Calcium hypochlorite is 21.4% soluble in water @ 25 degree Celsius. And if the solution is kept for longer time it will happen reversible reaction.

So, it is a problem for us, and that's why the bleach should not keep more than Six Hours after dilution because reducing of Chlorine (gas form) from diluted solution will finally make the bleaching solution less effective while applying in the washing bath.

And the diluted solution should be always mixed very nicely using the revolving motor each and every time while taking the bleach for application in the washing bath.

Always - remember that, Chlorine is the reducer, it reduces the color from the dyed portion.

Thanks for reading.

Best regards,
K M Zahidur Rahman

How to bleach & dyeing jute fiber/ Fabric?

Jute is a long, soft, shiny vegetable fiber that can be spun into coarse, strong threads. It is produced primarily from plants in the genus Corchorus, which was once classified with the family Tiliaceae, and more recently with Malvaceae. The Corchorus capsularis. "Jute" is the name of the plant or fiber that is used to make burlap, hessian or gunny cloth.

Chemical composition of jute fiber:

Cellulose - 65.2 %

Hemi- Cellulose 22.2 %

Lignin 10.8 %

Water Soluble 1.5%

Fat and Wax 0.3 %

Physical Property of Jute Fiber:

1) Tenacity (g/den): 3.5 ~ 4.5 or (40-70 g/tex)

2) Length: 0.2-30 inch

3) Stretch and Elasticity: Not good and 2% elongation at break

4) Resiliency: Not very good

5) Abrasion Resistance: Relatively good

6) Dimensional Stability: Good

7) Moisture Regain: 13.75%

8) Specific gravity: 1.48~1.50

9) Color: Yellowish, Yellow, Brown, Golden

10) Heat Resistance: Good

11) Specific Heat: 0.324

12) Diameter: 18 micron

13) Cross section: Uneven, Thick cell wall with lumen.

Chemical Properties:

1) Effect of Bleaching: Not affected by oxidizing and reducing bleaching agents

2) Effect of acid: Destroyed by hot concentrated acids. Dilute acid can't do harm to the fiber

3) Effect of alkali: strong alkali destroy the fiber and strength reduces

4) Organic solvent: Resistant to organic solvents

5) Effect of Mildews: Better than cotton and linen

6) Effect of insects: Resistance is good

7) Dye ability: Good, easily dyed.

8) Electrical and thermal conductivity: Moderate

Bleaching Process of Jute Fiber/Fabric-

 

Bleaching of Jute:
Although jute fibres contain considerable amount of impurities, jute materials are generally bleached without prior scouring due to its alkali sensitivity. Jute differs from linen in its high lignin content (about 11-12% dry weight). The lignin, together with hemicelluloses, provides inter-cellular binding material known as lamella, holding the fibre together. In contrast to linen, it is neither desirable nor necessary to delignify jute. Jute is effectively bleached by hydrogen peroxide while most of the lignin remains.

A consequence of the presence of lignin in bleached jute is that its whiteness is not fast to light.

Bleaching Process:
Jute may be successfully bleached with sodium hypochlorite solution having 3-7 g/l available chlorine, using sodium carbonate to maintain pH of 10 to 10.5 at room temperature for 1 to 2 hours. It is advisable to add 1 to 2 g/l wetting agent, when the material is directly bleached without scouring. It is then washed and anti-chloride with 0.2% sodium sulphate for 20 minutes at 50 ̊C.

Sodium chlorite is suitable for bleaching of jute. It removes more lignin than hydrogen peroxide. Treatment of jute fabric with acidified 4% (o.w.m.) sodium chlorite solution, pH 4 to 4.5 at 90 ̊C for 90 minutes improves the whiteness of the materials.

The bleaching with hydrogen peroxide causes a markedly lower loss of weight (10% as against 17.9% in chloride bleaching) and slightly lower loss in strength.

In jigger machine, the recipe (% O.W.M.) of jute bleaching as follows:

• Hydrogen Peroxide of 50%  : 3 to 6%
• Sodium Silicate : 6 to 8%
• Caustic Soda : 0.5 to 0.7%
• Nonionic Detergent : 0.2 to 0.5 %
• Chelating Agent : 0.05%
• pH : 10.5~11
• Temperature : 80 to 85 ̊C
• Time : 120 minutes

The brightness of peroxide bleached jute material was found to increase when pre-treated with an enzyme mixture containing cellulose and xylanase.

The conventional hydrogen peroxide bleaching requires high temperature which may damage jute material. 

So cold bleaching may be carried out by treating the jute materials with a solution containing -

6% hydrogen peroxide, 

4% caustic soda, 

4% sodium silicate, 

2% soda ash and 

1% soap 

- followed by 24 hours storing at room temperature. The whiteness achieved may not be very high.

- In that case after completing 24 Hours bleaching process , the jute materials should be washed using clean water and then optical textile brighter can be used to achieve more brightness. Optical textile brighter can be used at 1~3 g/l to make the solution based on to dip the whole mount of jute material in the bucket/ tank.  Dipping time may be : 1~ 2 hours.

Ambient temperature processing: 

Some other main parameters and considerations regarding ambient temperature processing as given as under:

Processing of jute is difficult due to its complex chemical structure. Bleaching of jute is done in such a way that it produces sufficient whiteness without damaging fiber. Dyeing process is also selected in such a way that it does not damage the fiber and at the same time results in optimum fastness and dye uptake. Jute being bulky and hygroscopic, requires a considerable amount of water and thermal energy for its processing and subsequent drying. Effluent released after processing creates water pollution. Considering the resource management issues involved in jute processing, including the ease of processing in small operations, this study is focused on performing both bleaching and dyeing at ambient temperature without using thermal energy or sacrificing product quality.

Ambient Temperature Bleaching Process :

The possibility of bleaching of jute at Ambient temperature has been explore using sodium persulphate as peroxygen booster. The process is dependent on four variables. hydrogen peroxide, sodium hydroxide, sodium silicate and sodium persulphate, which has been optimized by using the statistical technique, central composite rotatable plan (CCRP). 

A recipe using -

50 g/l of hydrogen peroxide (50%), 

30 g/l sodium hydroxide (Flake), 

25 g/l sodium silicate, 

5 g/l sodium persulphate, 

5g/l non-ionic surfactant and 

0.25 g/l magnesium sulfate 

-   is suggested to obtain an acceptable level of whiteness without affecting the strength. The method involve padding the fabric in the solution using 90 - 100% wet pick up and then batching for 3 hours followed by washing

DYEING PROCESS -

Ambient temperature dyeing Cellulose is the main component in jute which participates in the dyeing of jute fiber. So, all the dyes which are suit able for dyeing of cotton fiber can be used for jute with some modification. Considering both the fastness of colour and cost of dyeing, reactive dyes are found to be best for jute dyeing. It was found after extensive study that dichlorotriazine and vinyl sulphone reactive dyes can be applied judiciously on jute fiber at ambient temperature. Process involves exhaustion of dyes on jute followed by fixation in alkali bath. 

It is important to note that -
70-80 g/l glauber's salt is needed during exhaustion, 
20-30 g/l sodium carbonate is required for fixation of dichlorotriazine and 
5 g/l sodium hydroxide 
- is required for fixation of vinyl sulphone reactive dye on jute.

 

Thanks for reading!

B.R

Zahidur

Executive- (Hameem Group)