CASE STUDY: WELL WATER TREATMENT USING REVERSE OSMOSIS AND 70% WATER RECOVERY FOR KC KNIT CONCERN LTD IN BANGLADESH

The need

TheKnit Concern Groupis a leading group in Bangladesh, managed by its Managing Director, Chairman and Founder, Mr Joynal Abedin Mollah, who, right from the start of building the Knit Concern textile empire, has always been a visionary and has consistently anticipated the needs of both production and the market.
The aim was to produce water similar to that found in the Alps in order to manufacture garments of the highest quality and with a delicate feel, just as is achieved with high-quality Italian production. To achieve this, the water supply is essential, as it is the water itself that determines the quality of the textile product.

The solution

WaterNext has developed a cutting-edge project capable of treating well water at an early stage and, with three units, guaranteeing a production of over 7,500 m³/day; however, the innovation also lies in the fact that, once the water circuit has been purified, the same systems can be used to treat wastewater, significantly reducing the use of natural well water and recovering the discharged water.
A single plant can treat any water source – from river water to well water to wastewater – whilst consistently ensuring a quality of output equivalent to that of water sourced from the Italian Alps.

TheGOAL

The plant is designed to produce 7,500 m³/day of permeate, with a final TDS of less than 100 mg/L, iron content of less than 0.01 mg/L and an indicative residual hardness of approximately 10 mg/L as CaCO₃.
The WaterNext solution provides stable water for textile production, thereby ensuring an improved impact on the final textile product, greater protection of the membranes, a lower risk of scaling and better operational continuity.

The project contect

KC Knit Concern LTD, a textile company based in Bangladesh, uses well water at various stages of production, including washing, dyeing, rinsing and finishing. Founded in 1990, KC is a vertically integrated textile company specialising in the manufacture and export of knitwear and lingerie.
In these processes, the availability of water with consistent characteristics is essential to ensure high quality of the finished product, repeatability of the manufacturing processes, and the plant’s operational continuity.
The raw water had a conductivity of less than 530 µS/cm, TDS of less than 385 mg/L, hardness of up to 400 mg/L as CaCO₃ and silica of less than 61 mg/L. Iron, turbidity and suspended solids were also present, parameters which required specific treatment before the water could be used in the production departments.

The technical challenge

The main issue centred on the hardness of the water and the presence of substances that could potentially cause deposits and scaling. Without appropriate treatment, these factors could have reduced the efficiency of the equipment, increased chemical consumption and led to more frequent cleaning and maintenance operations.
Variable water quality could also have affected dyeing formulations, colour yield and the stability of the various production stages. KC Knit Concern LTD therefore needed a solution capable of consistently producing 2,500 m³/day of treated water, whilst controlling salinity, hardness, iron, turbidity and suspended solids.

The WaterNext solution

WaterNext Group has designed a comprehensive range comprising multimedia filters, cartridge filters and a two-stage reverse osmosis system.
The multimedia filters form the first line of defence in the system and reduce turbidity, suspended solids, iron and manganese. The cartridge filter retains the finest residual particles, protecting the high-pressure pumps and the membranes installed downstream.
The first stage of reverse osmosis achieves the main reduction in dissolved salts, conductivity and hardness. The second stage, on the other hand, acts as a polishing stage, further improving the quality of the permeate and ensuring a more stable water supply that is better suited to the needs of textile production.

Results achieved

The plant is designed to produce 7,500 m³/day of permeate, with a final TDS of less than 100 mg/L, iron content of less than 0.01 mg/L and an indicative residual hardness of approximately 5–10 mg/L as CaCO₃.
The solution developed by WaterNext provides KC Knit Concern LTD with treated water of controlled quality, reducing the risk of scaling and protecting membranes and equipment. The result is greater process stability, reduced maintenance requirements and improved production continuity.