BWD-01 Water Decoloring Agent for High-COD Knit Dyeing Effluent in Bangladesh

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.

Textile Wastewater Problem in Bangladesh

The central treatment problem is that 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 dose, 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.

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.

Technical Specifications

Recommended Application Scenarios

• Knit dyehouses processing black, navy, red and other high-depth shades.
• Composite ETP influent from dyeing, washing and finishing departments.
• Final color-polishing stages before sedimentation or dissolved-air flotation.

How BWD-01 Works

1. Charge neutralization: cationic groups interact with negatively charged reactive dyes for cotton knit fabrics and colored colloids.
2. Destabilization: reduced electrostatic repulsion allows dissolved or finely dispersed color bodies to associate.
3. Floc formation: the destabilized contaminants form visible aggregates; PAC may strengthen or densify flocs where testing supports it.
4. Solid-liquid separation: the resulting flocs are removed by sedimentation or air flotation, producing clearer treated water.

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.

Recommended Application Procedure

1. Collect a representative wastewater sample after appropriate screening and equalization.
2. Prepare several BWD-01 working solutions by diluting the product with 10 to 40 times clean water.
3. Use pH 7.5-8.0 as the TDS starting range for improved performance, then test nearby values if necessary.
4. Dose BWD-01 into the wastewater and mix thoroughly for several minutes.
5. Where color and CODcr remain high, test PAC before and after BWD-01 in separate beakers. Do not premix the chemicals.
6. Allow the flocs to settle or evaluate them by dissolved-air flotation, matching the site's full-scale process.
7. Compare final color, CODcr, turbidity, floc strength, separation time, sludge volume and total treatment cost before scale-up.

Expected Treatment Results

The BWD-01 TDS reports typical decolorization of approximately 50%-99% and CODcr reduction of approximately 50%-80% in suitable applications. These are reference ranges, not guaranteed results. 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. The comparison should use dry solids, dewatering behavior and disposal cost where sludge reduction is a project objective.

Bluwat Manufacturing Advantages

• Manufacturer since 2000 with more than 25 years of water-treatment chemical production and export experience.
• Three production bases supporting stable supply, batch control and multiple packaging options.
• Products exported to more than 80 countries and used by over 5,000 industrial customers.
• Quality and environmental systems including ISO 9001 and ISO 14001, with ZDHC-conformant BWD product support.
• Routine control of appearance, solid content, specific gravity, pH, viscosity and solubility, supported by batch COA.
• Free sample availability and technical support for jar-test design, dosage comparison and full-scale trial planning.
• Standard BWD-01 packaging in 30 kg and 250 kg plastic drums or 1250 kg IBC containers.

For Asian textile markets, Bluwat supports drum and IBC shipments, production planning for regular consumption, and remote jar-test review using the customer's wastewater data and treatment photographs.

Frequently Asked Questions