Wastewater: differences between domestic and industrial types

Understanding wastewater types for efficient and sustainable water resource management

In a context of growing environmental awareness and responsible resource use, wastewater management is now a top priority. Understanding the nature and differences between domestic and industrial wastewater is the first step toward adopting appropriate and effective treatment solutions.

When properly treated, wastewater can represent not only a resolved problem but also a recoverable resource to reintegrate into production cycles, contributing to sustainability and the circular economy.

Characteristics of domestic wastewater

Domestic wastewater comes from homes, offices, and all civil structures that use water for personal hygiene, cooking, cleaning, and toilet flushing. Its characteristics are relatively consistent and include:

• High content of biodegradable organic matter;
• Presence of soaps, detergents, and food residues;
• Variable amounts of nitrogen and phosphorus (especially in toilet effluent);
• Significant but predictable bacterial load.

If untreated, this wastewater can disrupt the balance of receiving water bodies, promoting eutrophication and microbiological contamination.

What is industrial wastewater

Industrial wastewater has more complex and variable characteristics that depend heavily on the type of production activity it comes from. It may contain:

• Heavy metals (such as zinc, lead, copper);
• Chemical solvents and hydrocarbons;
• Toxic or non-biodegradable substances;
• Residues from thermal or mechanical processes, such as oils, greases, dust, and suspended solids.
   

These effluents can be highly polluting, difficult to treat, and potentially hazardous to the environment and human health. They therefore require targeted, sector-specific treatment for each industry (chemical, textile, food, metallurgical, agricultural, etc.).

Wastewater treatment must comply with Italian and EU regulations, which require actions to achieve or maintain good quality status of surface and groundwater, protecting them from pollution.

Treatment of domestic wastewater

The treatment of domestic wastewater generally involves three stages:

• Primary treatment, to remove large solids and floating materials;
• Secondary (biological) treatment, where microorganisms degrade organic matter;
• Tertiary treatment, to remove nutrients and residual microorganisms, especially when reuse is planned.

These processes are well-established, automatable, and often centralized in public treatment plants. However, there are also decentralized solutions ideal for isolated homes, small communities, or hospitality facilities.

How industrial wastewater is treated

Industrial wastewater, given the composition we’ve described, requires a completely different treatment approach, which we’ve already explored in detail.

This treatment needs a thorough analysis of the contaminants present. In many cases, an on-site pretreatment is necessary before discharge into the sewer system or reuse. The technologies employed include:

• Physico-chemical processes, for contaminant precipitation or separation;
• Advanced filtration (membranes, reverse osmosis, ultrafiltration);
• Advanced oxidation techniques, for breaking down toxic compounds;
• Specific biological treatments, using bacteria selected for high-contamination environments.

The complexity of industrial effluents requires custom-designed plants that are flexible and upgradable to match the company's evolving needs.

Differentiating wastewater types for better treatment

Knowing the differences between domestic and industrial wastewater is essential for defining the best treatment strategy. Each type has specific pollutants and characteristics that demand tailored solutions.

The environmental challenge ahead calls for smart wastewater management capable of turning waste into a resource. Thanks to Idro Group’s experience, today it’s possible to meet this challenge with expertise, innovation, and a forward-looking approach.

Idro Group’s solutions for addressing the water crisis

Idro Group specializes in designing and building both domestic and industrial wastewater treatment plants.

These systems collect large quantities of water and, through specific treatments, can return clean water with organoleptic, chemical, physical, and biological qualities that meet legal standards and can be reused for many purposes.

Wastewater treatment plants can be custom-designed based on the specific sector’s needs and the type of contamination to address. Especially for industrial wastewater, which—as we’ve seen—has highly variable composition, it’s crucial to customize treatment plants by choosing technologies and processes suited to different treatment requirements.

Idro Group also designs containerized treatment plants: mobile, versatile solutions for treating wastewater from both traditional and unconventional sources, where the raw water composition isn’t always known. These plants offer an effective, flexible and rapid response in emergency, temporary, or remote contexts.

If you’re looking for more specific information about wastewater treatment plants or would like to schedule a consultation, fill out the form in the contact section. We’ll get back to you as soon as possible!