Physical [2] [8]

Chemical [8] [9]

Biological [5] [8]

Natural [10] [11]

Definition

Type of treatment that focuses more on filtration methods or gravity treatment like sedimentation.

Treatment of wastewater by infusing a chemical (like chlorine or hydrogen peroxide) that expedite the disinfection and killing of any organisms.

Type of treatment that relies on bacteria and microbes to breakdown the waste matters included and treat the wastewater.

Ecological self-treatment systems that ensure ecosystem balance relying on natural factors like sunlight and temperature. They are considered as a biological treatment division.

Pros

Partially removing organics, particulate pollutants, nitrogen, and phosphorus nutrients.

Also, it reduces the risk of damage for the next treatment phase as it removes any solids mixed in the wastewater used.

Faster disinfection process when compared to other solutions, might produce high amounts of sludge which ensures effective wastewater treatment.

The chemicals used are mostly available and not expensive in cost. Sometimes lesser treatment exposure time is used like in the UV treatment stage.

Efficient and cost effective when compared to mechanical systems, and it is the optimal option for organics removal.

More cost-effective and efficient based on the primary treatment method used.

Easy to install and in some cases it is considered as a landscape decorative treatment method.

Cons

Inefficient total suspended solids removal.

Requires longer time for treatment.

Doesn’t remove any organic matters or kill any bacteria or pathogens.

With the high amounts of sludge produced, their toxicity levels and volumes need to be considered when disposed.

Electricity might be used like in the Ion Exchange or Electrochemical coagulation, hence more cost. Sometimes not all pathogens or microorganisms are removed like in the chlorine treatment and even if TSS is high some can be ineffective like UV.

Cannot be used as a sole treatment method, it is preferred to be used as a secondary treatment after a sedimentation primary treatment.

With aerobic/anaerobic treatment, high levels of sludge are produced.

Preferred to be used as a secondary treatment specially in domestic post-treatment usages.

Needs high maintenance and can be seasonably reliable based on the plants used.