What is a wastewater treatment system?

A wastewater treatment system is the process of removing contaminants from wastewater generated by use in an industrial plant. Applying wastewater treatment technology produces clean, good-quality water before preparing it for a water recycling system. Wastewater can be treated by a number of methods, physical, biological and chemical, depending on the wastewater problem in question.

importance of wastewater treatment in industry

Why an industrial plant needs a wastewater treatment system

Beyond turning wastewater into clean water, installing a wastewater treatment system in an industrial plant has a number of other advantages:

  • Legal compliance: meeting the effluent standards currently in force
  • Reduced environmental impact: less pollution, and less accumulation of toxic substances in watercourses
  • Economic value: recycling water back into use, reducing water costs and corrosion-related maintenance costs
  • Improved reputation: demonstrating responsibility towards society and the environment

5 wastewater problems that an industrial wastewater treatment system can solve

Industrial wastewater problems can range from minor issues to serious challenges with large-scale impacts. The following are 5 common wastewater problems that can be effectively managed with wastewater treatment systems.

1. Wastewater with a foul odour, and BOD/COD above standard

The problem of foul-smelling wastewater usually arises when there is too much organic matter in the water, requiring the microorganisms used in treatment to consume large amounts of oxygen for decomposition, producing hydrogen sulphide (H₂S) and ammonia. This results in BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand) values above standard. Normally, BOD must not exceed 20 mg/L and COD must not exceed 120 mg/L.

Under the Ministry of Industry Notification on the control of effluent standards from factories, B.E. 2560 (2017), if discharged water has BOD and COD values above the standard, legal penalties apply for example, financial penalties, an order to cease discharging wastewater, or the licence being considered for revocation.

2. Wastewater contaminated with oil and grease

Food and beverage processing plants, and plants manufacturing metal components, frequently encounter the problem of discharged water contaminated with oil, grease and residual chemicals. Without good wastewater treatment technology, this leads to floating sludge, blockages in drainage pipes, and wide-ranging environmental damage, because grease adhering to the water surface obstructs the transfer of oxygen from the air into the water, reducing dissolved oxygen and affecting aquatic animals and the aquatic ecosystem.

wastewater problems because inefficient treatment system

3. Wastewater contaminated with minerals and heavy metals

Wastewater containing large quantities of minerals results in severely polluted water. When it escapes and contaminates natural watercourses, the environmental impact is severe. It can be removed by chemical stabilisation to precipitate the contaminants, together with filtering out remaining highly charged ions through an Electro Conductivity Reducer (ECR) system or RO, before discharge to the public environment or the mineral-filtered effluent can be recovered for reuse. The minerals separated from the wastewater must then be crystallised into a solid form.

4. Wastewater with high sediment and suspended solids

Wastewater with large quantities of sediment and suspended solids arises from raw material washing, or from production processes contaminated with organic and inorganic matter such as gravel, clay, sand and material fragments. Without appropriate wastewater treatment technology, suspended solids remain high, causing blockages within the treatment system. If discharged into public watercourses, this creates turbidity, reduces oxygen levels in the water, endangers aquatic life, and ultimately accumulates as bottom sediment.

5. Wastewater accumulating faster than it can be treated

Many plants have a problem with large volumes of wastewater accumulating, particularly during periods when production must be accelerated. If an unsuitable wastewater treatment system is in use, wastewater overflows the treatment tanks and the system blocks easily. Wastewater must then be released from the plant into natural watercourses. Which may lead to financial penalties or a legal order to cease discharging.

Get a modern, high-efficiency wastewater treatment system designed and installed by the expert team at Econowatt. Our solutions help factories treat wastewater effectively and produce high-quality clean water for reuse within their operations.

Learn more about our available solutions on the Our Solutions page.

modern wastewater treatment solutions

Solving these problems with an industrial wastewater treatment system

Installing a wastewater treatment system to address these problems generally divides into 3 treatment stages:

Preliminary treatment

A physical treatment stage that separates large, water-insoluble contaminants using screens, passing them into a settling tank. Some plants may add a grease removal system to reduce problems with grease accumulation in the wastewater. Preliminary treatment methods include:

  • Trapping contaminants with separation screens
  • Settling to prevent pump blockages
  • Grit and sand removal
  • MBDAF (Micro Bubble Dissolved Air Flotation), which uses micron-scale air bubbles to separate sludge, oil and grease from the water
  • Biomicrogel, a bio-based oil capture agent that is environmentally friendly and captures oil more effectively than general chemicals

Secondary treatment

Treatment at this stage focuses on reducing the contaminant load of the wastewater by chemical or biological means. The method must be considered against the characteristics of the wastewater in each case. Wastewater treatment systems used at the secondary stage include:

  • Aeration systems, such as the activated sludge process, which uses microorganisms to help decompose organic matter
  • MBR (Membrane Bioreactor), which combines biological processes with membranes, producing clearer water and reducing odour more effectively than before

Advanced treatment

Advanced wastewater treatment is a process for removing suspended solids that are difficult to settle, along with nutrients and colour that cannot be removed at the intermediate stage. In most cases, installing wastewater treatment technology at this stage is intended to bring water quality to the highest level so that it can be safely reused. Systems used at this stage include:

  • UF (Ultrafiltration) filtration, filtering to as fine as 0.01 micron
  • ECR (Electro Conductivity Reducer), a technology that reduces ionic content in water by using electricity to separate charged particles without chemicals, in order to reduce TDS and the true colour caused by dissolved minerals
  • EHR (Electro Hardness Removal), using electric current to separate calcium and magnesium from water without chemicals, in order to reduce water hardness
  • Ozone wastewater treatment (Ozone Water System), which helps disinfect and reduce colour and odour
  • Automatic control systems, monitoring water quality in real time
sustainable wastewater treatment by econowatt

Install a modern wastewater treatment system for sustainable industrial standards

An industrial wastewater treatment system is an innovation that delivers real value to industrial plants today. Beyond complying with Department of Industrial Works requirements, it also helps improve production efficiency and establishes long-term sustainability standards for the plant.

For plant owners looking to install a quality wastewater treatment system suited to real-world operation, Econowatt designs wastewater treatment systems and advises on installation to solve wastewater problems, with more than 30 years of experience. We are ready to be the partner that raises your production and wastewater treatment standards to meet requirements and move towards genuine sustainability.

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Reference: กรมโรงงานอุตสาหกรรม

Frequently asked questions about wastewater treatment systems (FAQs)

Q: How does an activated sludge wastewater treatment system work?

A: The system uses microorganisms to help decompose organic matter in wastewater, with aeration added so the microorganisms can work at full efficiency. This helps reduce BOD and COD values to within standard levels.

Q: Do small factories need to install a wastewater treatment system?

A: Yes. Every factory producing discharged water from its production process must comply with environmental law, in order to help reduce the impact on surrounding communities.

Q: Do modern wastewater treatment systems use a lot of energy?

A: New technologies such as MBDAF and EHR use less energy than older wastewater treatment systems and can be configured to operate automatically, helping to reduce costs over the long term.

Q: Can treated water be reused?

A: Yes, provided the water recycling system has been properly designed. However, the water should be filtered and its quality checked before every use.