Oct 20, 2019

Textile Wastewater Reuse for Pollution Prevention

This article was originally published as "Textile Wastewater Treatment" in the September print edition of iWWD.

Reviewing progression of wastewater treatment for dyes and fabrics

The textile industry is an intensive industry for the consumption of water because water is used for various steps in the textile dyeing process. It also is necessary for cleaning the raw material. 

Due to stricter environmental regulations, continued pushes toward sustainability, and the effects of regional water scarcity, the cost of fresh water consumption has increased globally. Additionally, pressures on businesses to maintain or increase profit margins for their stakeholders are another driver toward water reuse in textile wastewater applications.

Within this industry, companies utilize different quantities of water, depending on equipment used, specific processes used at the mills, the fabric used, and the company’s philosophy toward the utilization of water.

The processing of wool and cotton yarn materials requires an elevated consumption of water compared to other subcategories, such as nylon or polyester. The varied amounts of textile wastewater produced by textile processing facilities present several challenges.

These challenges include treatment chemicals, power consumption, sludge disposal costs and operating cost or surcharges associated with wastewater treatment. These critical issues create the challenges of efficiently and effectively managing water with a strategic focus on sustainability. Energy consumption is a vital component of textile processing operations that should not be underplayed.

Providing sustainable treatment solutions to meet these important goals limits water pollution from entering local water bodies to preserve surrounding ecosystems and safeguard public health.

Representative Textile Wastewater Analysis

Normally, textile wastewater effluent from processing operations requires measurement of the specified attributes listed below:

• Inorganics, such as metals, phenols, color, pesticides, and certain surfactants, including refractory/non biodegradable organics;

• Total suspended solids (TSS) at elevated levels;

• Chemical oxygen demand (COD) and biological oxygen demand (BOD); and

• Relatively high levels of total dissolved solids (TDS).

Monitoring these parameters and other possible pollutants can ensure proper treatment in facilities that use conventional primary treatment methods, including biological reactors for wastewater treatment. These pollutants also provide challenges to wastewater treatment facilities on a municipal level, as these treatment plants normally are not equipped to treat contaminants in an effective and efficient way.

Electrocoagulation for Textile Wastewater Treatment

Implementing a new method of advanced primary and secondary water treatment solutions is fundamental to meeting the challenges faced by the textile industry now and in the future.

Electrocoagulation is one of the emerging water treatment solutions capable of treating the different waste water characteristics of textile industry effluent. This advanced technology uses the functions and benefits of conventional coagulation, flotation and electrochemistry in water and wastewater treatment to optimize contaminant removal in a cost-effective and sustainable way.

This specialized solution offers companies with existing and new wastewater treatment systems benefits by optimizing current treatment processes, reducing operating and maintenance costs, improving dependability, reducing sludge disposal costs, and mitigating environmental concerns related to toxic non-biodegradable solids sludge disposal.

Advanced electrocoagulation water treatment solutions add value in several aspects of the textile wastewater treatment process. These aspects include primary pre-treatment to remove or reduce nonbiodegradable, toxic compounds and color prior to a biological process. It also can be used as polishing pretreatment for specific contaminants, such as colloidal organics, minerals or microbiological contaminants prior to ultrafiltration (UF) or reverse osmosis (RO) desalination systems.

Textile Wastewater Reuse & Sustainability

Textile wastewater treatment and reuse is a promising solution to conserve and increase available water resources and reduce harmful pollution discharge into the environment. This is particularly noticed in water-stressed countries across Africa, Asia and Latin America, where the textile industry is of particular importance to local economies.

As companies in this industry move toward meeting sustainability goals to reduce operational costs and comply with stricter regulations, it is becoming clear that water reuse is one of the fundamental components of these initiatives.

Textile companies typically produce wastewater comprising high levels of dissolved and suspended solids, and color from their operations, in addition to potential nonbiodegradable contaminants. Based on the levels of contaminants discharged, the municipal wastewater disposal surcharge costs for the textile company may fluctuate. Reusing this water potentially can provide a significant return on investment for textile producers not only through the removal of wastewater disposal charges, but also through the reduction of the cost to procure fresh water as well.

Specialized electrocoagulation wastewater treatment solutions—including those from Genesis Water Technologies—have shown value in textile water reuse applications by eliminating or reducing chemical costs, reducing operating cost for secondary and tertiary treatment systems, and significantly reducing sludge disposal costs when compared to conventional chemical treatment methodologies.

Future Textile Wastewater Trends

The textile industry will continue to integrate advanced innovative water treatment solutions to reduce its water footprint, reduce its overall operating costs and decrease the ecological impact from its wastewater discharge and solids sludge generation on the ecosystem.

Wastewater treatment process optimization will continue to be an important point for textile industry companies, as the costs of wastewater disposal and fresh water consumption continues to increase due to issues involving water scarcity.

Water reuse and sustainability will continue to be relevant goals for environmental pollution prevention reduction practices in the textile industry.

With an ever growing and progressively affluent global population, demands on our global water resources can lead to higher water costs and stricter regulations. This is propelling textile companies and municipalities alike to re-evaluate their practices and advance toward a more sustainable future.

More efficient methods coupled with advanced treatment solutions to treat and reuse waste water and process water will remain one of the most critical points of textile manufacturing companies across the world into the future. 

Treatment Application

A textile company wanted to reuse the wastewater discharge from its washing and textile dyeing operations to reduce its fresh water consumption costs and maintain compliance with increasingly stricter discharge regulations.

Genesis Water Technologies (GWT), with its local partner, designed and provided a solution to effectively handle its water streams. The raw effluent was pumped from the primary holding tank through a self-cleaning filter to extract the suspended solids. The pre-screened wastewater stream exited the self cleaning filter and was collected in a tank to be delivered by way of a centrifugal pump to a GWT specialized electrocoagulation and electro-oxidation systems followed by an incline plate clarifier for flocculation using Zeoturb bio-organic flocculant to remove solids. Tertiary treatment included advanced GWT sediment filtration systems and RO desalination systems to provide clean water to be reused for textile production operations.

There was a 75% reduction in discharge costs. Additional operating cost reductions were apparent from the reduction of fresh water consumption used in the textile washing and dyeing processes. Discharge compliance was maintained with lower sludge disposal costs which increased the clients return on investment.

About the author

Nick Nicholas is technical director for Genesis Water Technologies. Nicholas can be reached at [email protected].

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