Knit Dyehouses
Black, navy, red and other high-depth reactive-dye shades from cotton knit processing.
Bluwat BWD-01 Water Decoloring Agent
Textile Dyeing Wastewater Treatment in Bangladesh
A cationic decoloring solution for cotton knit reactive-dye wastewater, designed to improve charge neutralization, floc formation and reliable solid-liquid separation during rapidly changing shade schedules.
50% minSolid content
pH 7.5-8.0Recommended starting range
30 / 250 / 1250 kgStandard packaging
01
Product Overview
Textile wet processing in Bangladesh does not create one uniform wastewater. Fiber type, dye class, shade depth, washing recipe and finishing chemistry can change the color and charge demand from one production batch to the next.
BWD-01 supplies strong cationic charge to destabilize negatively charged soluble dyes and fine color-bearing particles. It is especially relevant to reactive dyes for cotton knit fabrics.
The objective is not merely to make the sample look clearer, but to produce flocs that can be separated reliably by sedimentation or dissolved-air flotation.
02
Textile Wastewater Problem in Bangladesh
Deep-color batches, intensive washing and short production schedules produce fluctuating color and COD loads at the ETP. Conventional inorganic coagulation may remove suspended solids but leave a visible soluble-color fraction.
Operators may then increase coagulant dosage, creating more sludge without proportional color improvement.
Why the Problem Occurs
Reactive dyes that do not fix on cotton are discharged during washing and soaping.
Detergents, leveling agents and softeners add soluble COD and can keep fine contaminants dispersed.
Rapid shade changes and large batch releases can exceed the equalization tank's buffering capacity.
03
BWD-01 Treatment Solution
Use BWD-01 after representative equalization, with pH and dosing checks focused on dark-shade peaks rather than on average daily color only.
The selected program should be based on actual wastewater rather than a universal dose. A controlled jar test identifies the point where charge neutralization, floc formation, separation speed and sludge production are balanced.
PAC can be tested before or after BWD-01, but the two products must be prepared and dosed separately.
04
Technical Specifications
| Property | BWD-01 Specification |
|---|---|
| Chemical Name | Quaternary ammonium cationic polymer |
| Appearance | Colorless to yellowish translucent liquid |
| Solid Content | 50% min |
| Specific Gravity at 20 C | 1.1-1.3 |
| pH Value, 30% Solution | 3-6 |
| Viscosity at 25 C | 30-300 cps |
| Solubility | Soluble with water at any rate |
| Storage Temperature | 0-35 C |
| Standard Package | 30 kg or 250 kg plastic drum; 1250 kg IBC |
Technical note: Values are based on the Bluwat BWD-01 TDS. Confirm the supplied batch with its Certificate of Analysis and consult the SDS for handling and shelf-life details.
05
Recommended Application Scenarios
Composite ETP Influent
Mixed wastewater from dyeing, washing and finishing departments with rapidly changing load.
Final Color Polishing
Color-removal stage before sedimentation or dissolved-air flotation in the full-scale ETP.
06
How BWD-01 Works
Cationic groups interact with negatively charged reactive dyes for cotton knit fabrics and colored colloids.
Reduced electrostatic repulsion allows dissolved or finely dispersed color bodies to associate.
Destabilized contaminants form visible aggregates; PAC may strengthen or densify flocs where testing supports it.
The resulting flocs are removed by sedimentation or air flotation, producing clearer treated water.
07
How to Choose and Test BWD-01
Build separate jar-test curves for light, medium and dark shade schedules.
Track sludge settleability because maximum color removal is not always the lowest-cost operating point.
Confirm the effect of softeners and detergents on floc formation.
Use untreated and current-treatment controls in every jar-test series. Record raw-water pH, true or apparent color, CODcr, turbidity, temperature and production source. Photographs are useful, but analytical results and sludge behavior are required for a defensible selection.
08
Recommended Application Procedure
Collect representative wastewaterTake the sample after appropriate screening and equalization.
Prepare BWD-01 working solutionsDilute the product with 10 to 40 times clean water.
Screen wastewater pHUse pH 7.5-8.0 as the TDS starting range, then test nearby values where necessary.
Dose BWD-01Add it to the wastewater and mix thoroughly for several minutes.
Test PAC sequenceWhere color and CODcr remain high, test PAC before and after BWD-01 in separate beakers. Do not premix the chemicals.
Evaluate separationAllow flocs to settle or evaluate them by dissolved-air flotation, matching the full-scale process.
Compare final performanceReview color, CODcr, turbidity, floc strength, separation time, sludge volume and total treatment cost before scale-up.
09
Expected Treatment Results
The BWD-01 TDS reports typical performance ranges in suitable applications. These are reference values rather than guaranteed results.
50%-99%Typical decolorization reference range
50%-80%Typical CODcr reduction reference range
Actual performance depends on dye class, concentration, auxiliaries, pH, mixing, chemical sequence and separation equipment.
Compared with a high-dose inorganic-only program, BWD-01 may provide faster flocculation and settling and may reduce the inorganic contribution to sludge. Where sludge reduction is a project objective, compare dry solids, dewatering behavior and disposal cost.
10
Bluwat Manufacturing Advantages
Manufacturer since 2000 with 25+ years of production and export experience
Three production bases supporting stable supply and batch control
Products exported to 80+ countries
Used by 5,000+ industrial customers
ISO 9001 management systems
ZDHC-conformant BWD product support
Routine quality control supported by batch COA
Free samples and jar-test technical support
30 kg, 250 kg drum and 1250 kg IBC packaging
For Asian textile markets, Bluwat supports drum and IBC shipments, production planning for regular consumption, and remote jar-test review using customer wastewater data and treatment photographs.
11
Frequently Asked Questions
Can BWD-01 help a knit dyeing ETP during dark-shade production?
Yes. Dark reactive-dye batches are a core screening application. The plant should use a representative peak-load sample, adjust pH, and compare BWD-01 alone with a separate BWD-01 and PAC program.
Should dosage be based on daily wastewater flow?
Flow is needed for feed-rate calculation, but dosage concentration should be based on water quality. Color strength, CODcr, shade schedule and auxiliary load can change even when the daily flow is similar.
What is the recommended BWD-01 dilution and wastewater pH?
The TDS recommends dilution with 10 to 40 times water and identifies wastewater pH 7.5-8.0 as a useful starting range. Final dilution, pH and dosage must be confirmed using the actual effluent.
Can BWD-01 be mixed directly with polyaluminum chloride?
No. BWD-01 and PAC should be prepared and dosed separately. PAC may be added before or after BWD-01 depending on the flocculation test and treatment process, but the concentrates should not be premixed.
How should the final BWD-01 dosage be selected?
Use a jar test with representative wastewater. Compare color, CODcr, turbidity, floc size, separation time and sludge volume. The best operating dose is the lowest stable dose that meets the plant's complete treatment objective.