Industrial wastewater treatment is essential for many businesses working across manufacturing, food production, chemical processing, and more. Understanding how industrial wastewater treatment works helps facility managers optimise their operations and stay compliant with regulations, while protecting the environment.
Why Industrial Wastewater Needs Specialist Treatment
Industrial wastewater is not like domestic sewage – depending on what is being manufactured, it could potentially contain heavy metals, organic compounds, oils, suspended solids, or have extreme pH levels. Every industry produces different wastewater, which means treatment solutions need to be tailored to specific needs.
Before any treatment starts, a comprehensive analysis needs to be completed to identify what contaminants are present, their concentrations, and what discharge standards need to be met. This analysis is the foundation of an effective treatment strategy and is the basis of OMEX Environmental’s services.
Removing Large Solids and Suspended Particles
Primary treatment for wastewater is all about removing physical contaminants through screening and sedimentation. Screening catches debris and materials that would damage equipment further down the line, while settlement tanks use gravity to separate heavier particles (which sink as sludge) from lighter stuff like oils and greases (which float to the surface).
This initial stage can remove up to 60% of suspended solids and cuts down the organic load significantly before wastewater moves to more advanced processes.
Getting the Chemistry Right
Chemical treatment tackles contaminants that physical processes don’t remove. There are three main approaches: pH adjustment, coagulation, and flocculation.
pH adjustment
Many industrial processes produce wastewater with extreme pH levels which can be devastating to the local environment if they are introduced to rivers or lakes. Wastewater with extreme pH levels must neutralise high acidic or alkaline levels before discharge or further treatment. Modern pH control solutions provided by OMEX Environmental are safer and more accurate than traditional methods, and there’s less risk of overcorrection.
Coagulation
This process destabilises suspended particles that carry negative charges and repel each other. By neutralising these charges, coagulants let particles come together, making it easier to remove them. Inorganic coagulants (aluminium or iron-based) are more cost-effective but they generate more sludge while OMEX Environmental’s coagulants work effectively in smaller doses and produce less waste.
Flocculation
These bind destabilised particles into larger clumps called flocs, which settle or float out much easier. Gentle mixing is required here – enough to promote floc formation but not so much that it breaks apart the aggregates.
Using Microorganisms to Break Down Organic Matter
Secondary treatment uses biological processes to remove dissolved organic compounds that chemical and physical methods can’t address. This is where microorganisms come into play.
Aerobic treatment
This brings in oxygen to support bacteria that consume organic pollutants. Common systems include activated sludge processes, trickling filters, and rotating biological contactors. These microorganisms need proper nutrition though – most industrial wastewaters don’t have balanced nitrogen and phosphorus levels, so they often need to be supplemented with nutrients to keep the microbial population healthy and working efficiently.
Anaerobic treatment
This works without oxygen, using different bacterial species to break down organic matter. It’s particularly good for high-strength industrial wastewaters and it produces biogas that can be captured and used as renewable energy. Anaerobic systems need careful monitoring to prevent acidosis and keep conditions stable.
Meeting Standards Through Advanced Treatment
Tertiary treatment provides a final treatment to meet strict discharge standards or prepare water for reuse. This could include membrane filtration (which removes remaining particles, bacteria, and some dissolved compounds), sand filtration (trapping fine particles), or activated carbon filtration (removing dissolved organics, colours, and odours).
It might also require nutrient removal to prevent eutrophication in rivers and lakes. Chemical precipitation works for phosphorus, whilst biological processes or advanced oxidation deal with nitrogen compounds.
Dealing with the Sludge
Wastewater treatment always produces sludge that needs proper management. How much is produced and what it’s like depends on the treatment processes and what’s in the wastewater to begin with.
Thickening – removes water to reduce sludge volume, which makes handling more economical. Gravity thickening, dissolved air flotation, or centrifugation can all be used here.
Dewatering – mechanically removing water through belt filter presses, plate and frame filter presses, or centrifuges. The end result is often called “cake” and typically contains 15-40% solids.
Keeping Everything Running Smoothly
Effective treatment needs continuous monitoring of pH levels, dissolved oxygen, chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS), and whatever specific contaminants are relevant to your industry.
Modern plants use automated systems that adjust chemical dosing, aeration rates, and other parameters in real-time. This keeps everything performing optimally without needing constant manual intervention.
Staying on the Right Side of Regulators
There are discharge consents that specify maximum concentrations for various pollutants. These consents vary depending on whether the water is being discharged to sewers, rivers, or other water bodies.
Regular sampling, testing, and keeping detailed records are crucial – not just for proving compliance but also for spotting opportunities to improve ongoing processes.
Turning Wastewater into a Resource
If wastewater is treated to high standards, there are more opportunities for reuse. This cuts both freshwater consumption and disposal costs as treated water can work as cooling tower make-up water, process water for non-critical applications, irrigation water, or for toilet flushing and vehicle washing.
Environmental Protection and Cost Savings
Effective wastewater treatment protects rivers, lakes, and coastal waters from pollution. It safeguards aquatic ecosystems and public health. But the benefits aren’t purely environmental.
When you optimise treatment processes, it reduces chemical consumption, energy use, and disposal costs. Reusing water decreases freshwater abstraction charges. Reliable compliance means avoiding penalties and reputational damage, while plenty of businesses find that investing in efficient systems pays for itself pretty quickly through reduced operating costs and better sustainability credentials.
Choosing a Treatment Approach
Picking the right technologies means considering the characteristics of the wastewater and flow rates, discharge consent requirements, site constraints, capital and operating budgets, water reuse objectives, sludge disposal options, and environmental goals.
Working with experienced wastewater treatment specialists like OMEX Environmental makes sure the system is properly designed, efficiently operated, and capable of meeting both current and future requirements.