Basics of Wastewater Treatment

by Sauber Environmental Solutions Pvt. Ltd. We preserve Environment for better tomorrow.
Wastewater treatment has become a must-do with clean water shortages plaguing the world. With depleting freshwater resources, water scarcity is becoming one of the largest threats to the world. Today, the world needs new treatment technologies to generate clean water out of wastewater and thus to mitigate the effects of water scarcity. It has become imperative to treat the wastewater and reuse it instead of disposing of the dirty polluted water in our holy rivers & polluting our environment. There are numerous water treatment companies in India that do the good work of treating the contaminated water for its suitable reuse.

Wastewater treatment process aims to reduce the pollutants/contaminants to an acceptable limit & to make the water safe for reuse or its discharge back into the environment. With cutting edge treatment technologies wastewater can be treated to standards needed for process application in the industries (i.e. feed water of Cooling towers, Boilers, Equipment washings, floor cleaning etc.), gardening, and recreational activities and even make it suitable and safe for discharging in the river. This activity will not only reduce the stress/load on freshwater resources but will also save our environment from pollution and will also generate an alternate source of clean water. This is an important step which will make our Earth a happily living pollution-free planet.

Wastewater Treatment Process

Let’s get down to understand the extensive step by step wastewater treatment process. Basically, it has three main stages of treatment – Primary Treatment, Secondary Treatment, and Tertiary Treatment. Each stage works on different principles of treatment and remove/reduce different kind of pollutants present in wastewater, making water cleaner as it passes through different stages of treatment. Type of treatment to be adopted for the treatment of various kinds of wastewater varies & it mainly depends upon the kind of pollutants present in it & and the intended final reuse of treated water.

1. Primary treatment

Wastewater during its journey from its source of generation to disposal point/treatment plant may get polluted with big floating impurities like plastics, paper, wood logs, cans, plastic bottles, torn clothes & sand/grit. Primary treatment is aimed to remove these floating large size impurities from wastewater along with sand & grit. 

Treatment units provided for primary treatment include Coarse mechanical/manual screens followed by grit removal channels with grit bucket collector at wastewater pumping stations & medium/Fine mechanical screens followed by Detritor Grit removal chambers/vortex grit removal chambers/aerated grit chambers at treatment plants. Some of the treatment plants may also have oil & grease removal trap after grit removal unit if the raw wastewater also contains high oil & grease content along with other impurities as described above. After oil & grease removal, wastewater is lead to clarification step (sometimes along with Flocculation), where wastewater is allowed to settle under quiescent conditions & residual settleable suspended impurities are removed from wastewater in the form of sludge. Primary treatment removes about 25-30% of the organic load from wastewater along with color and other floating impurities removal & hence reduces the load on downstream Biological treatment. Also, the primary treatment increases the life of rotary equipment like pumps in the plants & reduces the choking issues in the pipeline.
The collected screenings, sand/grit, oil & grease, and sludge is sent to a solid waste disposal site for their proper disposal in the environment.

2. Secondary treatment

After primary treatment, wastewater is led to the Secondary treatment section for further treatment. Main purpose of secondary treatment is to remove organic load (COD & BOD) from wastewater with the help of microbes. There are basically two types of biological treatment- Anaerobic or Aerobic. In Anaerobic treatment, wastewater is treated under oxygen free environment and in Aerobic treatment wastewater is treated under air/oxygen rich environment with the help of external air supply arrangements (Fine bubble Diffused aeration coupled with air blowers, surface aerators or aspirators as per the design requirement).
Latest secondary treatment technologies include Sequential Batch Reactor technology (SBR), Moving Bed Bioreactor technology (MBBR), and Membrane Bioreactor technology (MBR). Although, conventional Activated sludge process/Extended aeration is also extensively used even today.
Biogas generated as a byproduct in anaerobic treatment is an important source of energy and is used to generate electricity using biogas-based engines. Sludge from the aerobic section is also a good source of manure for agricultural activities. Sludge if not used, is also dewatered at the treatment plant and is sent to a solid waste disposal site for its proper disposal in the environment

3. Tertiary Treatment

The purpose of tertiary treatment is to further enhance/polish the secondary treated wastewater to comply with the standards of final treated water quality requirements. Tertiary treatment includes treatments like chlorination/ozonation/UV treatment for disinfection, filtration/disk filtration/Ultrafiltration for suspended solids removal, chemical treatment for color removal and reverse osmosis for dissolved solids removal. The type of treatment to be adopted will depend upon the final treated water quality requirements. 

Sauber Environmental Solutions is one of the industry-leading effluent treatment plant companies in India who could guide you treatment type that is best suitable as per your needs. We will guide you for optimum utilization of the wastewater and will make your investment completely worth it.

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About Sauber Environmental Solutions Pvt. Ltd. Junior   We preserve Environment for better tomorrow.

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Joined APSense since, August 16th, 2019, From Ahmedabad, India.

Created on Oct 15th 2019 07:37. Viewed 400 times.


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