TT stands for Tertiary Treatement, which is a process whose ultrafiltration aims to remove bacteria and macromolecules downstream of a secondary clarifier unit. The application with pressurized membranes is usually used to obtain a very high quality permeate to be re-used in agriculture, or within industrial production cycles. The pressurized ZeeWeed membranes are made of two different materials, depending on the type of application required, PVDF or PES. The first material produces a hollow fiber membrane whose surface is made up of billions of pores that act as a physical barrier for impurities, but that allow water molecules to pass through. ZeeWeed PVDF membrane devices for tertiary applications work in an OUT-IN configuration: i.e. the direction of filtration goes from the outside of the hollow fiber towards the inside, so that the suspended solids remain outside the membrane while only the permeate (clarified water) reaches the internal channel of the fiber (lumen) from where it is then collected and sent to the final discharge. The variant in PES differs in work configuration, which is IN-OUT, and in the type of construction of the membrane itself, which provides a multichannel tubular fiber within which the pressurized wastewater to be filtered is started. The PES allows the membrane to remain permanently hydrophilic and reduces the tendency to foul.
Membranes used for tertiary applications are grouped in modules located in pressurized vessels organized in pre-assembled skids according to the required surface. The particular configuration of the module allows it to be connected directly to the other modules and to the permeate manifold, thus constituting a self-supporting element ready to be positioned without the need to build frames and piping (Rackless solutions).