The newest most sustainable wastewater recovery processes for industrial wastewater treatment

Since the 2000s, I have closely observed the growing awareness of rationalizing water consumption, a development that did not surprise me: alarming signals about the depletion of vast aquifers have sparked international mobilization with the aim of countering this escalating threat.

NUMBERS
Currently, about one-third of the world’s largest aquifers are undergoing depletion, with 20% of them being overexploited – according to FAO.
The risk factors for this precious natural resource are manifold, with the primary ones including population growth, insufficient precipitation, and, not least, inefficiency in enforcing existing laws.

The limited control capabilities of authorities or the lack of clear and restrictive regulations are the primary catalysts for excessive and unregulated exploitation of aquifers. My experience has allowed me to witness how these issues need to be urgently addressed with a more conscious approach, even by major corporations. Ensuring the sustainability of this vital resource for our planet is paramount.

In this scenario, how can businesses navigate to safeguard water resources? What elements can we recognize in companies at the forefront of wastewater recovery, starting from the methods used?

INTRODUCTION

Water sustainability through water recycling

As I mentioned earlier, especially in the last decade, there has been a heightened awareness of water scarcity. The rising costs and difficulties in sourcing this resource have led to mobilization by major European and American purchasing groups, which have re-evaluated the role of suppliers. Stricter rules have been imposed on these suppliers, both regarding discharge regulations and water recovery/reuse, often surpassing local regulations.

A fundamental requirement for large Western buyers, therefore, becomes the search for suppliers who adhere to environmental discharge regulations and demonstrate plans for implementing a water recovery system. In this regard, the role of the Sustainability Manager becomes a key factor within purchasing and decision-making groups. This figure has the ability to influence the future production plans of major industrial groups, including those in the fashion and furniture sectors.

Returning to the initial question: what parameters should the Sustainability Manager consider in selecting suppliers? And how can one identify those truly recovering wastewater? Let’s explore these aspects together.

ANALYSIS

Impacts of traditional wastewater treatment methods

Wastewater can have various effects on the environment if not adequately treated before release. It may introduce pollutants into the surroundings, promote eutrophication of aquatic environments, and cause harm. Moreover, untreated wastewater can negatively impact human health by releasing pathogens such as bacteria or viruses.

To mitigate these adverse effects, it is essential for businesses to adopt state-of-the-art wastewater treatment technologies before discharging them into the environment, ensuring the safety of both the ecosystem and human health.

Water treatment: environmental impacts

Choosing the right partner suppliers depends crucially on the water recovery methods they employ to mitigate environmental effects. Let me provide some context on how processes have evolved, framing three main focuses:

• Treated wastewater release – Until the 2000s, the international community aimed to encourage industries to use wastewater treatments to release less polluted water into the environment;
• Wastewater recovery and reuse – Since the early 2000s, discussions have centered around recovery systems. Initially, recovery did not exceed 40%, utilizing sand and resin filtrations. However, these methods did not allow for the removal of salts from the water. In the textile industry, where the use of salts is substantial, using highly saline water means recovering aggressive and corrosive water for textile machinery. Subsequently, the adoption of reverse osmosis became prominent, being the only technology capable of removing Total Dissolved Solids (TDS), specifically salts.

We have detailed the evolution of these processes in our article.

Indeed, it is these different approaches to water treatment that assist the sustainability manager in selecting more responsible and sustainable suppliers, favoring those who adopt reverse osmosis. If you are a sustainability manager, inquire with potential partners: which of these systems are they employing?

FOCUS

Is reverse osmosis the most advanced wastewater treatment?

If a company utilizes reverse osmosis processes, it is truly at the forefront. In fact, reverse osmosis is the system that has enabled the recovery of up to 95% – 98% of wastewater. This brings significant advantages: lower initial investment costs, reduced operational expenses, decreased use of chemicals, no production downtime, complete automation, and a long lifespan for the entire system.

The revolution (and evolution) of reverse osmosis

Reverse osmosis is the result of various experiments conducted over the last two decades.
The initial recovery systems allowed for up to 70% recovery through a single stage, later increased to 85% with two stages. Let me explain better what single and two stages mean.

Reverse osmosis is a sophisticated filtration system that allows the separation of treated water into two streams: the purified water, referred to as permeate water, and the concentrated contaminants, known as concentrate or reject flow. This process is typically referred to as a single-stage reverse osmosis, enabling the recovery of approximately 70% of permeate water (the exact percentage depends on the water’s characteristics).

In situations where it is necessary to further increase the recovery percentage, a second stage of reverse osmosis is required. This involves treating the reject flow from the first stage with a second reverse osmosis unit. In turn, this generates another permeate flow and a reject flow, potentially improving the overall recovery to up to 85%. However, the exact percentage remains contingent on the specific characteristics of the water being treated.

However, many issues remained associated with this treatment. Reverse osmosis, in fact, required treated water at a degree that ensured the almost absence of total suspended solids (TSS) to prevent them from clogging the system. In the first decade of the 2000s, this osmosis pre-treatment involved:

• biological treatment, through the use of bacteria
• secondary sedimentation
• quartz filtration
• ultrafiltration.

These were sophisticated treatments that made the system delicate, manual, and expensive in both economic and operational terms. Only in 2010 was it possible to replace intermediate treatments (sedimentation, quartz filtration, and ultrafiltration) with a single membrane treatment, known as M.B.R..

WHAT IS M.B.R.?
It is an adequately aerated tank used to eliminate organic contaminants, bacteria, and other pollutants. These reactors create a controlled environment where microorganisms, essential for wastewater treatment, can degrade and break down organic contaminants present in water or solid waste. Through the biological reactor, the pollutant load of the effluent can be reduced without the use of chemical substances. Know more.

HANDBOOK

Finding companies that save water by recycling

Returning to the main point: which recovery systems should a sustainability manager prioritize when choosing a partner company?

When identifying suppliers, the following factors should be kept in mind.

The water treatment plant must be 100% biological

Wastewater treatment should be cutting-edge, utilizing bacteria and organic substances to degrade contaminants into smaller compounds. Advanced systems, in fact, avoid the use of chemical components.

At least 90% of contaminants must be removed from wastewater

It’s not enough to reduce contaminants; the impact must be practically zero. State-of-the-art systems, like reverse osmosis, allow for a recovery of up to 95% – 98%. Methods that recover less are too outdated. The implementation of biological treatment, as seen, is a necessary preliminary or preparatory phase for environmental recovery. Only through these processes can wastewater be released into the surrounding environment or reused.

Sustainability is also economic

True sustainable recovery must also be in terms of time and budget. It should be achieved with the least investment, providing the maximum yield, as in the case of MBR and reverse osmosis. This also demonstrates a company’s astuteness and economic sustainability.

Rely on certifications and regulations

It is interesting to verify which international and third-party certifications a company has received, thanks to wastewater recovery as well. Additionally, the presence of regulations related to wastewater treatment in the countries where these companies operate is an additional indicator of reliability.

Search for partners in countries already specialized

Not only Japan, Italy or the USA: India, Bangladesh, China, Sri Lanka, and Mexico also have forward-thinking companies in wastewater treatment. Professionals in these countries are driven by the goal of spreading these niche technologies to developing countries.