Limitations of Conventional Methods
Various conventional water purification methods have been widely used in the field, but each comes with its own limitations. No single method is universally effective for all types of contamination.
Here, we introduce five typical purification methods and their inherent limitations: physical treatment, chemical treatment, biological treatment, adsorption treatment, and chemical oxidation treatment.
Physical Treatment
Techniques such as sedimentation, filtration, and flotation are effective for removing suspended solids and particulate matter.
However, they cannot target dissolved organic compounds or heavy metal ions in water.
Filtration in particular faces unavoidable issues such as clogging and performance degradation, requiring regular cleaning or replacement of filters. This leads to significant operational costs and maintenance burdens.
Chemical Treatment
This method uses chemical agents for coagulation, precipitation, neutralization, or redox reactions to separate contaminants from water.
However, the cost of required chemicals is high, and there is a risk of producing harmful by-products through side reactions.
Additionally, the disposal of chemical reaction residues raises concerns regarding both cost and environmental impact.
Biological Treatment
Techniques like the activated sludge process or biofilm treatment rely on microorganisms to decompose organic matter.
These methods are widely used in treating domestic and industrial wastewater.
However, maintaining sufficient microbial activity requires large-scale facilities and sophisticated management, including oxygen supply and control of temperature and nutrients—resulting in high operational costs.
Moreover, biological treatments often fail to decompose persistent organic pollutants, limiting their applicability.
Adsorption Treatment
Using activated carbon or ion-exchange resins, this method adsorbs and removes harmful substances from water.
However, adsorbents have a finite adsorption capacity, and their effectiveness declines significantly once that limit is reached.
Regular replacement or regeneration of adsorbents is necessary, making this method costly and labor-intensive for large-scale or long-term applications.
Chemical Oxidation Treatment
This method decomposes pollutants using powerful oxidizing agents such as ozone or hypochlorous acid.
It is expected to be effective even against persistent organic compounds.
However, the high cost of equipment and chemicals is a major drawback.
Additionally, oxidation reactions may produce harmful by-products (e.g., chlorinated compounds), requiring strict environmental management.
Careful control of oxidant dosage and reaction conditions is also essential to maintain stable treatment performance.
Underlying Social and Operational Bottlenecks
The fundamental challenges of conventional water treatment technologies are not limited to technical aspects — they also stem from deep-rooted social and operational issues.
- High Cost Structure：Advanced treatment technologies involve significant expenses, including initial investment, chemical costs, equipment replacement, and labor.
- Energy Dependency：Many conventional processes consume large amounts of electricity — for example, aeration in biological treatment or chemical reactions in oxidation processes.
Especially with advanced methods like reverse osmosis (RO) or UV treatment, the energy demand is high, making operation difficult during disasters or in areas with unstable power supply. - Complex Management and Operation：These systems often require multi-stage controls and skilled personnel for daily operation and regular maintenance.
- Difficulty Handling Diverse Contaminants：It is challenging for a single technology to remove a wide variety of pollutants.
As a result, combinations of different methods are needed at each site, complicating system design and management.
Expectations for Next-Generation Technologies
Despite ongoing advancements in purification technologies, their limitations in terms of operation, cost, and sustainability are becoming increasingly evident.
In particular, emergency situations, disaster sites, remote facilities, and areas with limited infrastructure demand solutions that are simpler, more flexible, and highly effective.
In response to these challenges, a new purification technology — SepaTech Microbubble — has been developed.
The following section will explain its system structure and the key role of microbubbles in detail.