Textile dyeing operations face paramount challenges all around the world. As huge water consumers, it surely is demanding for textile plants to adapt to the new demands and requirements coming from authorities, and most importantly, from the general society, which is the more and more concerned with the industry’s environmental footprint. Thus, changing existing plants or building new ones are measures of utmost urgency when it comes to creating feasible wastewater treatment solutions for the textile dyeing industry. Care must then be taken when choosing optimal wastewater treatment solutions.
Textile companies may go from simply rejecting wastewaters into municipal sewer systems or may want to comply with the most stringent demands, such as ZLD (Zero Liquid Discharge). The latter is more and more popular among large textile producing countries. Yet, no matter the chosen alternative, new technologies always have to be introduced, as the traditional approach to treat wastewaters from the textile industry is no longer compatible with the new demands and requirements. So, new technologies, such as AOP (Advanced Oxidation Processes) – in which electrocoagulation and perozonation are included, alone or together – may be key technologies to introduce in revamping, retroﬁts, and even in new plants. They help the textile industry reach the challenging new rejection limits, complying with most stringent regulations, and allow for eﬃcient and proﬁtable wastewater reuse, adding great value to the whole process.
What do they do?
The customer at stake is the world leader in zipper manufacturing. Thus, it has been for years the world reference for impeccable production standards. It relies on tight quality control processes for slide fasteners, plastic hardware, hook and loop fasteners, webbing tapes, and snap and buttons.
Even though many plants use chemical and biological water treatment systems, compliance issues, diﬃculty in reusing treated water and operating costs are still a struggle. So, the key to overcoming these problems lies in oxidative pre-treatment, such as coupling an electrocoagulation process to a biological one. Such technology involves a powerful oxidation process which removes detergents and surfactants, thus solving Chemical Oxygen Demand (COD) problems, removing color, decreasing salinity, and preparing eﬄuent to recovery and reuse plants. Electrocoagulation of wastewater is the future for wastewater treatment solutions for the textile dyeing industry. It is a particularly efficient technology for plants that present high salinity levels, increased reject water volumes, alarming operating costs, and overall, low eﬃciency indicators.
The presented wastewater treatment solutions for the textile dyeing industry allowed for the total removal of color, surfactants and, consequently, COD and BOD. At the end of the day, clean and clear water comes out of our client’s plants, at a ﬂow rate of 6 m3/h. Also, the company at stake now presents lower operating costs and decreased sludge production. Eﬃciency that outperforms by a lot a standard chemical process.
This customer had to comply with more stringent rejection limits, as its rejected wastewater goes directly into a water stream connecting to a river. Its main concern was with color and detergent levels. Taken that into account, VentilAQUA provided wastewater treatment solutions that ensure the desirable results: total solids removal, total color removal, tensioactives level below 2 ppm, ﬁnal COD below 120 ppm, and all other parameters within the rejection limits for direct environmental discharge.