What Is a Wastewater Treatment System? Process, Importance, and Explanation

Wastewater treatment is the process of separating unwanted materials from wastewater to allow treated wastewater to meet its discharge or reuse criteria. Treatment options are determined by the wastewater source, pollutant properties, flow rate, and water quality desired.

Containerized wastewater treatment is a combination of several treatment processes in a single small, mobile treatment unit that is used when space, installation time and mobility are important considerations. A system can be biological treatment, dissolved air flotation, chemical treatment, membrane filtration, nanofiltration, or reverse osmosis depending on the application.

Understanding these processes can assist businesses in selecting a wastewater treatment system that suits the specific wastewater instead of relying on treating it by capacity alone when comparing wastewater treatment system manufacturers.

What Is a Wastewater Treatment System?

A wastewater treatment system is a series of processes that are used to remove certain pollutants from a wastewater stream. A single method of treatment is not always appropriate.

Suspended solids, oils, organic matter, heavy metals, or refractory substances may be present in industrial wastewater. Various technologies are thus deployed based on the characteristics of the wastewater, its pollutant content, and the desired quality of discharge or reuse.

For various industrial wastewater applications, QILEE offers ready-to-use process combinations like DAF, chemical treatment, MBR, TUBEUF, NF, and RO.

How Does a Wastewater Treatment System Work?

There are a number of stages in the treatment process. Not all technologies are needed for all projects.

1. Dissolved Air Flotation and Chemical Dosing

Where there are suspended solids, oils, and colloids in the wastewater, DAF can be used as a pretreatment.

Chemical dosing provides assistance to the particles to form larger flocs. Dissolved air bubbles cling to these flocs and bring them to the surface, where the floating material is removed.

This helps decrease the amount of pollutants that are put into the other stages of treatment.

2. Chemical Treatment

Certain pollutants cannot be treated by physical or biological methods alone but need targeted chemical treatment.

Heavy metals, recalcitrant organic material, phosphorus, and other challenging pollutants are treated with chemical treatment. Selection of treatment chemicals depends on the wastewater and the chemical to be removed.

3. Biological Treatment With MBR

Membrane bioreactor (MBR) is a technology that integrates biological treatment with membrane separation.

The biological system facilitates organic matter degradation; the treated water is separated from the activated sludge by the membrane. This results in an integrated treatment process combining biological treatment with solid/liquid separation.

Decentralized domestic sewage can be treated by A/O + MBR and A²/O + MBR processes. The A²/O method is a combination of anaerobic, anoxic, and aerobic phases for providing biological nutrient treatment.

4. Tubular Ultrafiltration

Tubular ultrafiltration is applicable to difficult industrial effluents with high suspended solid content, high viscosity, or potentially fouling effluents.

A high velocity of water flowing through the membrane channels is achieved with the tubular membrane design. The process can hold some suspended solids, colloids, bacteria, and macromolecular organic matter.

5. Nanofiltration and Reverse Osmosis

Additional membrane treatment, such as NF and RO, is used if deeper purification is required or when desalination is needed.

Divalent ions and some organic compounds can be removed using nanofiltration, and using reverse osmosis can further separate out dissolved salts and other contaminants.

NF and RO can be combined to provide further purification or to reuse industrial water.

Why Is Wastewater Treatment Important?

Treatment objectives are determined by the wastewater source and the treated water's use.

Industrial facilities might require lowering suspended solids, oils, heavy metals, organic matter, or refractory substances before releasing them into the environment. Other applications may need more membrane treatment in order to be able to be reused in production.

Therefore, the process combination is dependent on the treatment objective. An example is that wastewater from food and beverages could be suited to a differently shaped configuration than pharmaceutical, metallurgical, or printing and dyeing wastewater.

The right treatment process can meet the requirements for discharge and at the same time provide opportunities for water reuse.

What Are the Advantages of Containerized Wastewater Treatment?

In containerized wastewater treatment, the treatment equipment, piping, valves, instruments, and controls are housed within a standard container.

The equipment can be integrated prior to moving to project site. Standard 20' and 40' containers are acceptable for use, and multiple containers may be used to create larger treatment capacities.

Key advantages include:

• Compact installation
• Faster deployment and transportation
• Flexible treatment configurations
• Less need for the complexities of site construction.
• Automated monitoring and control
• Ability to combine containers for larger capacities

QILEE also offers containerized solutions for decentralized sewage treatment, such as in towns, rural areas, resorts, and islands.

Which Industries Use Wastewater Treatment Systems?

The characteristics of wastewater are different in various industrial plants, and therefore treatment processes should be chosen as per these characteristics.

These are just examples of combinations and not general formulas. The process actually used may vary depending on the wastewater and the desired treatment outcome.

How to Choose Wastewater Treatment System Manufacturers

The selection of wastewater treatment system manufacturers should start with the wastewater itself.

Determine the wastewater source, flow, major pollutants, concentrations of pollutants, and effluent quality required. Then decide on discharge and/or reuse.

Additionally, it's paramount to see if the supplier can integrate various treatment technologies instead of just one static set. A modular approach can offer flexibility in wastewater characteristics and treatment needs.

For instance, QILEE provides different treatment configurations of containerized DAF, chemical treatment, MBR, tubular UF, NF, and RO technologies for various applications.

Where Can Containerized Systems Be Used?

Containerized treatment systems can be used for industrial wastewater, municipal wastewater, and decentralized wastewater applications.

Industrial uses include chemical manufacturing, food and beverage, metallurgy, pharmaceuticals, and printing and dyeing. The decentralized sewage system can be used in resorts, islands, rural areas, and towns.

Conclusion

A wastewater treatment system is an integrated treatment train where each process is chosen to treat a specific wastewater problem. Solids, oils, and specific pollutants can be treated by DAF and chemical treatment, and additional biological and membrane treatment is provided by MBR, tubular UF, NF, and RO as appropriate.

When mobility, compact installation, and flexible process integration are key considerations, containerized wastewater treatment provides a practical format. Wastewater treatment system manufacturers are to be compared with regard to wastewater characteristics, water quality required for the process, wastewater process compatibility, and possible reuse. It is more important to have a treatment train that is well matched than to add more treatment stages.