Waste Water Treatment Plants

Wastewater is used water originating from domestic, industrial, agricultural, and medical or transport activities. Used water becomes wastewater upon the difference in its quality, composition and/or potentially temperature.

The aim of wastewater treatment is to minimise the concentrations of specific contaminations to the dimension at which the discharge of the effluent will not adversely affect nature or represent a well-being risk. Moreover, the reduction of these constituents needs only be to some required level. Although water can technically be completely purified by distillation and deionisation, this is unnecessary and may actually be detrimental to the receiving water. Fish and other organisms cannot survive in deionised or distilled water.

For any given wastewater in a particular location, the degree and type of treatment are variables that require engineering and biological decisions. Often the degree of treatment depends on the assimilative capacity of the receiving water for the process. The amount of BOD that must be removed is an effluent standard and dictates in large part the type of wastewater treatment required.

To facilitate the discussion of the wastewater treatment process, assume “typical wastewater” and assume further that the effluent from this wastewater treatment must meet the following effluent parameters:
pH = 6.5 - 7.5
BOD (05 days at 20℃) ≤ 20 mg/L
COD ≤ 80 mg/L
SS ≤ 20 mg/L
P ≤ 1 mg/L

Additional effluent standards could have been established, but for illustrative purposes, we consider only these five. The treatment system selected to achieve these effluent standards includes the following process.

Primary treatment: physical processes which involve sedimentation of solid waste within the water and homogenise the remaining effluent.

Secondary treatment: biological processes that remove most of the biochemical demand for oxygen (BOD) from the water and makes use of oxidation to further purify wastewater. This method can be done in three ways: Bio-filtration, aeration and oxidation ponds.

Tertiary treatment: physical, biological, and chemical processes to remove nutrients like phosphorus and inorganic pollutants, to deodorise and decolourise effluent water, and to carry out further oxidation process. Substances like activate carbon and sand are among the most commonly used materials that are used in tertiary treatment.

Warranium Energy introduces WarraniumMBR(Membrane Bio-Reactor), a state-of-the-art membrane separation technology and WarraniumMBBR (Moving Bed Biofilm Reactor) for the streams like Domestic sewage, Primary and secondary wastewater, Pre-treatment for RO, cooling tower blowdown and municipal and industrial sector respectively.