Secondary treatment removes 85-90 percent of BOD, TSS, and a minor amount of nitrogen, phosphorus, and heavy metals from wastewater.
Tertiary sewage treatment is the third step of wastewater treatment and is also known as advanced treatment. Tertiary process eliminates the nitrogen and phosphate load from the water.
Treatment options in tertiary treatment are determined by the properties of the effluent, after secondary treatment as well as the type of water required at the end of the treatment.
Which is most used technology for tertiary sewage treatment?
Let’s understand the most widely used technology for tertiary sewage treatment.
1: Filtration Method
By passing water through porous material, the filtration process eliminates particle debris. The filtration process employs many types of media, which are often composed of sand, gravel, and charcoal. Slow sand filtration and fast sand filtration are the two types of sand filtration.
2: Membrane Method
Membrane technology is used to handle pollutants such as sewage, organic and inorganic debris, and water-soluble oil wastes. Membrane processes are categorised according to their driving force and separation mechanism, such as Micro Filtration (MF), Ultrafiltration (UF), Nanofiltration (NF), Reverse Osmosis (RO), and Forward Osmosis (FO).
Ultra-filtration (UF)
· UF membranes reject particles like silica, viruses, endotoxins, proteins, polymers, and smog/fumes. The osmotic pressure required is larger than that of MF because to the decrease in pore size.
· Ultrafiltration is thought to be a pre-treatment for RO systems, as it reduces scaling and fouling.
· The UF system is fully automated and PLC-based. The UF permeate will be collected and stored in the treated water tank.
· The purified water will then be disinfected using a solution of sodium hypochlorite.
Nano Filtration (NF)
· Nanofiltration is thought to be a pre-treatment for RO systems, as it reduces scaling and fouling.
· The NF system will be fully automated and PLC-based. The NF permeate will be collected and stored in the treated water tank.
· The purified water will then be disinfected using a solution of sodium hypochlorite.
Reverse Osmosis (RO)
· RO is a water treatment technology that forces water through a semi-permeable membrane, with very small holes or "pores."
· Impurities that are too large to pass through the membrane are left behind, and washed away as clean water goes through.
· Water is purified by passing pressurized water through a very fine, plastic membrane in reverse osmosis devices.
· If the treated raw water is from a well or another private source, disinfection and pre-filters (to remove chlorine and/or particulates/sediment) may be required, prior to the RO unit to eliminate pollutants that can foul or damage the membrane.
Ozone
To eliminate bacteria and breakdown organic pollutants, ozone is added into the process. By transporting oxygen through a high voltage electric field, ozone gas (O3) is generated. After chlorine, ozone is now the most extensively used disinfectant.
Advantages
1. In comparison to chlorination, ozone has a higher disinfection capacity against microorganisms, such as bacteria and viruses.
2. Ozone's oxidizing characteristics diminish the concentrations of iron, manganese, and sulfur.
3. It degrades or resolves taste and odour problems by forming insoluble metal, or elemental sulphur.
4. Organic particles and pollutants are removed through coagulation and chemical oxidation.
5. It has a high oxidizing power and a fast reaction time.
How can we assist?
Netsol Water offers a wide range of sophisticated sewage treatment solutions, such as ASP, MBR, MBBR, UASB, SBR, water softeners, RO Plants, advanced oxidation processes, etc. We also offer various technologies for tertiary sewage treatment.
Netsol Water is Greater Noida-based leading water & wastewater treatment plant manufacturer. We are industry's most demanding company based on client review and work quality. We are known as best commercial RO plant manufacturers, industrial RO plant manufacturer, sewage treatment plant manufacturer, Water Softener Plant Manufacturers and effluent treatment plant manufacturers. Apart from this 24x7 customer support is our USP. Call on +91-9650608473, or write us at enquiry@netsolwater.com for any support, inquiry or product-purchase related query.