Why More Enterprises And Communities Should Turn To Decentralized Wastewater Treatment

By Nick Nicholas

Decentralized wastewater treatment solutions aren’t limited to domestic services. As industrial effluent regulations become more stringent, many enterprises can turn to decentralized, onsite wastewater treatment. There are various advantages to implementing this solution, and specific industries can greatly benefit from doing so. However, before diving into those details, it’s essential to walk through the ins and outs of decentralized wastewater treatment.

What Is Decentralized Wastewater Treatment?

Decentralized wastewater treatment is a modular treatment plant disconnected from a sewer network. It can be used by communities and developments or placed onsite in an industrial facility. Given its location and non-existent link to a sewer network, a decentralized unit treats wastewater onsite, making it a sustainable, flexible alternative to large, centralized treatment plants requiring millions of dollars to build and maintain.

Types Of Decentralized Wastewater Treatment

If enterprises decide to use a decentralized wastewater treatment, there are different types of solutions they can implement. The first is a physical chemical treatment. With this type of decentralized wastewater method, a combination of electrocoagulation and pre- and post-clarification is used. However, electrocoagulation is at the core of the process.

While this term sounds intimidating, electrocoagulation is simply an electrochemical method that uses an electric current to remove emulsified, suspended, or dissolved contaminants from water. Various metal electrodes supply the electric current. After the anodes are oxidized, metal ions are released into the electrolyte to neutralize the charge of the solution. This process causes the contaminants in the water to destabilize. Additionally, the cathode refines the process by generating hydrogen microbubbles that encourage particles to float while the anodes undergo oxidation.

If enterprises use advanced physical chemical treatment, they could experience many benefits, primarily because electrocoagulation has multiple advantages, including the following:

• It’s an easy process: There are not many moving parts with electrocoagulation, so maintenance and oversight are minimal.
• Improves water quality: Research indicates that electrocoagulation can remove a significant amount of color, phenol, and organic matter.
• Cleans oily water: Electrocoagulation is one of the few methods that can treat oily water.
• Decreases cost: During the electrocoagulation process, a single system removes a significant amount of various contaminants, and recirculation time can be optimized to achieve the desired results. That makes this method incredibly cost-effective.
• Environmentally friendly: Electrocoagulation does not produce harmful or large volumes of sludge, so it’s better for the environment and less expensive to process and discard.

The second type of decentralized wastewater treatment is biological treatment. This kind of solution has two different types that will be discussed below.

The first is called a membrane biofilm reactor (MBR), and the second is known as a moving bed biofilm reactor (MBBR). The former is an aerobic biological treatment process that treats water and wastewater using a pressurized membrane that moves the gaseous substrate to the biofilm that’s developed on the membrane’s surface. The latter is a highly effective process founded on a hybrid combination of innovative biofilm media carriers and a conventional activated sludge process without the requirements of sludge recirculation.

The MBBR biological process utilizes a secondary clarification process that clarifies the wastewater before tertiary treatment begins. Determining which option to choose is based on the specific application, effluent treatment goals, and budget of the company.

Advantages Of Decentralized Wastewater Treatment

While the types of decentralized wastewater treatments vary, they have a couple of similar benefits. The first is that each solution increases water sustainability.

With a centralized wastewater treatment system, there are civil works requirements tied to running sewer networks, and those requirements add to the cost of the system as well as its upkeep and maintenance, making water sustainability an issue. If enterprises are not in an area with a dense population to access a centralized system, the best solution is to use a decentralized unit.

When the unit is onsite, the second advantage of decentralized wastewater treatment appears: decreased effluent disposal costs. Maintaining the pipes and pumps in a centralized system is very expensive, but the costs are drastically lower with a decentralized unit. Maintenance and contractor fees are more affordable because there are fewer components to maintain.

Which Industrial Sectors Need Decentralized Units?

Relying on decentralized wastewater treatment solutions can be advantageous for many industries. However, a handful of industrial sectors will benefit the most from using decentralized units. Those sectors include the following:

• Manufacturing: This category includes industries such as the food and beverage industry. For manufacturers, the main benefits are sustainability and reduced effluent disposal costs along with meeting regulatory requirements.
• Oil and gas: The primary benefits for this sector are lower operating costs, enhanced operations, and alignment with regulatory requirements, one of which is to have a decentralized unit on site.
• Chemical and petrochemical: Similar to the oil and gas industry, a decentralized unit can help the chemical and petrochemical sector reduce operating costs, boost operations, and meet regulatory standards, including the requirement to have a decentralized unit on site.
• Pulp and paper: This particular sector has challenges with suspended solids among other contaminants, so they are required to have a decentralized system onsite, even if they are linked to a centralized sewer network.
• Poultry and agriculture: This sector often struggles with suspended solids, residual nutrients, and pesticides in their streams. However, decentralized wastewater treatment can help in removing these toxins.

Given the advantages these sectors can experience, they are in a prime position to receive the most benefits from decentralized wastewater treatment. Some of them are even in situations where they are required to use a decentralized unit, making it imperative for them to implement this treatment solution.

Communities Can Benefit, Too

While many industrial sectors are positioned to reap the rewards that decentralized wastewater treatment offers, it’s important to reinforce that this solution is great for communities as well. Oftentimes, communities find that the cost of expanding or enhancing their centralized sewer network is expensive, especially if the system is relatively old or in poor condition. Building on an old or deteriorated sewer network is never ideal financially — and for communities that want to avoid paying a hefty price, decentralized wastewater treatment systems are the best option.

Moreover, suburban communities or island communities can especially benefit from decentralized units. Many of them don’t have the means to build and maintain a centralized sewer system. And in those cases, they require decentralized wastewater treatment. Otherwise, they have no paths to treating their water.

Implementing A Decentralized System Correctly

Whether it’s an enterprise or community, decentralized wastewater treatment can provide benefits. However, those benefits are only realized when the decentralized system is implemented correctly. Setting up this solution is not easy. You have to hire experts who are knowledgeable and experienced in designing, engineering, and supplying decentralized wastewater treatment solutions.

Nick Nicholas is the Technical Director for Genesis Water Technologies, Inc, a global leader in integrated solutions for drinking water and wastewater treatment. In this role and previous roles with GWT, he has coordinated and led a global team of technical professionals in designing, engineering, and building treatment system solutions for industrial, commercial, and water utility clients worldwide. Mr. Nicholas holds the distinction of being named one of the top 10 water professionals under 40 by Water & Wastes Digest magazine in 2019.