In order to break down how our proprietary separation system works, we first need to go over the composition of the wastewater and the contaminants that need to be removed in order to produce the product water theagoes to the filtration portion of The Eco System.
Wastewater has three main categories of contaminates, each requiring a specific strategy for removal.
Solid particles larger than 1 micron and with a specific gravity greater than 2.6. Their high density allows them to settle to the bottom of a settling tank or vessel. (i.e. sand, grit, silt)
Small solid particles which remain suspended in water as colloidal particles (1-10 microns), larger solid particles (greater than 10 microns) that remain suspended due to the motion of water, and microorganisms (.004-40 microns). A large percentage of the microorganisms (parasites, bacteria, and viruses) are attached to colloidal or larger solids with a small percentage of them free flowing.
Refers to any nutrients, heavy metals, organic compounds and other
minerals that are dissolved in water in molecular or ionized form. May also includes colloidal solids less than 1 micron in size.
The first polymer added to the wastewater is a coagulant that adds fresh cationic charges to the suspended colloidal solid particles to change their electrical charge to prepare them for agglomeration. Suspended colloidal solid particles naturally repel each other. Changing their charge causes them to attract to each other.
A grinder addresses the larger solids in the wastewater by slicing, chopping or grinding them into pieces that are smaller than 1/4“ in size to prevent clogging and to facilitate separation.
A flow pump is used to accelerate the wastewater to the proper flow rate allowing the polymers to fully mix within the piping without the need of a mixing vessel.
A Venturi air injector is an in-line device that based on its geometry injects millions of micro bubbles into the wastewater stream (reduces the pipe diameter to a narrow section that creates a vacuum that sucks in air then returns to the original pipe diameter. In the reduced pipe section, the water is under high pressure. Water under high pressure can become saturated with a high quantity of air. When the water goes back to the larger pipe diameter, the pressure is released, and the excess air dissipates out of the water in the form of micro air bubbles). These micro air bubbles attach to the surfaces of the suspended colloidal solid particles.
The second polymer added is a flocculant that combines the coagulant modified colloidal solid particles into larger agglomerated particles (50 to 200 microns in size). The flocculant encapsulates these micro air bubble entrenched suspended colloidal solid particles, trapping the air within these agglomerated particles which we call microfloc (50 to 200 micros in size). The entrapped air bubbles make these larger agglomerated particles lighter than water, making it rise to the surface.
A series of tight serpentine piping vigorously increase the flow rate and turbulence within the system which facilitates the mixing of the flocculant with the suspended solids in a shorter section of piping.
A hydrocyclone is a cone shaped device that creates an internal vortex. Heavy particles are push out against the cone shape and are forced downward by centrifugal forces exiting out of the bottom of the hydrocyclone. This device removes the settleable solids from the wastewater through this bottom exit port. The rest of the wastewater is forced out of the top exit port in a vertical vortex.
The hydrocyclone serves a dual purpose. Microfloc develops well in a high turbulent environment since it needs rapid mixing. However, the goal is to generate larger macrofloc which forms best in slow mixing environments. The hydrocyclone is a high turbulent environment. However, the water leaving the hydroclycone from the top port leaves imparted within a slowly dissipating vortex.
A second dose of flocculant is injected into the slowly dissipating wastewater vortex leaving the hydrocyclone. This second addtion of flocculant add to the already agglomerated particles forming larger floc called macrofloc that is larger than 250 micros in size.
A second Venturi air injector saturates the wastewater again with micro air bubbles. This time the micro air bubbles attach to the surfaces of the macrofloc agglomerated particles, adding a second layer of micro air bubbles to the floc, increasing even further the rise rate of these solids.
The wastewater then travels through a system of larger pipe sections that significantly reducing the velocity of the wastewater.
The wastewater exits the larger pipe sections into the top of a cone bottom circular flotation tank where the treated wastewater is allowed to quickly separate into sludge and product water. The rapidly rising macrofloc merges and clumps together at the top surface of the flotation tank into a thick sludge, and the product water exits through the bottom cone exit port.
Since the flow rate is greatly reduced in the flotation tank, a flow pump is used after the flotation tank to boost the flow rate of the product water back up to the desired flow rate and pressure necessary for the filtration systems that follow.
The first filtration system after the separation module is the disc filtration system. The primary function of the disc filtration system is to protect the following ultrafiltration membranes by eliminating any larger solids that may have been missed by the Eco Separation Module while further reducing the suspended and settleable solids. The efficiency and effectiveness of the Eco Separation Module combined with the disc filtration system are what make the following ultrafiltration system efficient and commercially viable. The remarkable low levels of suspended and settleable solids, in the product water going into the ultrafiltration system, allow for an extended membrane life while requiring less backwashing and maintenance. Without the disc filtration system, the ultrafiltration membranes would require backwashing frequently which would make it ineffective.
The primary function of the ultrafiltration system is to remove the large molecule dissolved solids (contaminant groups 5-9 from the table above) while eliminating the remaining suspended and settleable solids. The ultrafiltration system is fully automated and self-cleaning.
Ultraviolet germicidal irradiation (UVGI) is a disinfection method that uses short-wavelength ultraviolet light to kill or inactivate microorganisms by destroying nucleic acids and disrupting their DNA, leaving them unable to reproduce or perform vital cellular functions. Since the filtration systems that follow do not backwash, it is important to only send disinfected product water to the following section. At this point in the Eco System, the quality of the water leaving the UV disinfection system is at irrigation grade product water with abundant reuse application possibilities.
Depending on the level of purification, the application, and the type of dissolved solid contaminants (contaminant groups 5-9 above) found in the wastewater, the Eco System would require either a nanofiltration membrane system or a reverse osmosis membrane system which produces product water that exceeds the EPA and WHO primary drinking water standards.
Residual chlorine disinfection is a low level amount of chlorine applied and remaining in the water after a certain period or contact time after its initial application. It provides an important safeguard against the risk of subsequent microbial contamination after treatment and prevents any further contamination.
This concludes the Eco System. After the NF/RO stage, the quality of the water is at indirect potable grade product water.