Tertiary Treatment

Tertiary treatment involves treating the outlet from the secondary stage of an ETP or STP. The objective of tertiary treatment is to make the final treated effluent suitable for the following applications

1.	Discharge to land for irrigation / horticulture / green belt development
2.	Recycling to non chemical utility application
3.	To make the treated effluent suitable for feed to downstream recycling plants.

Tertiary treatment involves removal of residual effluents that remain in the treated effluent after it has undergone primary and secondary treatment stages. Typical contaminations that are treated for removal are:

	Residual suspended solids & turbidity
	Residual organics
	Colour & odour
	Further reduction of BOD & COD
	Colloidal matter

Aqua Designs offers variety of options for tertiary treatment, the treatment option is decided on laboratory trials, pilot plant testing and field testing and Designs.

Typical treatment options available are:

	Physico-chemical treatment using combinations of solid contact clarifiers and filters.
	Photochemical catalytic oxidation using Oxidizers like peroxide, ozone and chlorine in combination with irradiation with light of specific strength and wavelength.
	Pressure media filtration using customized catalytic media beds

Sludge Handling Systems

Aqua Designs offers comprehensive sludge handling systems to handle sludge from various sources such as

	Primary section which may contain chemical based / organic based sludge
	Biological sludge
	Tertiary section sludge

Sludge handling scheme involves a preliminary treatment to increase the sludge concentration which would be beneficial in reducing the load to the downstream treatment equipment. Typical treatment involving sludge handling will involve

	Poly electrolyte dosing
	Sludge thickener
	Sludge cake production

Aqua Designs utilizes various technologies to produce high quality sludge cake with minimum moisture content. The technology applied will be based on the nature and the quantity of sludge that is to be taken for cake formation. Frequently used equipment for sludge cake formation are:

	Plate and frame type filter presses
	Belt type vacuum based filters
	Bowl type centrifuges
	Progressive cavity type centrifuges

All systems are offered as manual systems with provision for upgradation to various level of automation. Options are available from the normal CI / SS 304 with options to upgrade to SS 316 L or Ti based alloys.