What are other methods for wastewater treatment? Suitable for papermaking wastewater

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1 Technical issues in air flotation treatment: Micro-porous aeration air flotation, dissolved air flotation, impeller air flotation, and jet air flotation are widely used in the treatment of papermaking wastewater. The two most cutting-edge existing ones. CAF vortex air flotation technology has made significant advances in mechanical bubble shearing, dispersion, and transfer, and exhibits excellent performance in the separation of cellulose and suspended solids, as well as in decolorization and deinking. The KROFTA high-efficiency shallow air flotation technology has advantages in water distribution and scum removal, overcoming some of the dead zones present in conventional dissolved air flotation; it performs well when applied to the recovery of white water from paper machines. In terms of operation, sludge accumulation in the air flotation tank, nozzle clogging, and tank cleaning are persistent problems in all air flotation processes.  2 Cyclone air flotation separator technology: What is introduced here is a new type of flotation centrifugation system—the cyclone air flotation separator. The cyclone air flotation separator includes a drive mechanism, a cylindrical cyclone chamber, a material guide, a pinwheel rotor, an aeration device, and a skimmer. Baffle plates are installed at the bottom of the chamber; there is a sludge hopper at the lower part, and an atomizing nozzle for adding chemicals can also be provided at the upper part. The upper part of the swirl chamber is equipped with a perforated or weir-type draining structure. The guide is conical in shape and can be stacked multiple times to remain coaxial with the rotor. The aeration device consists of multiple micro-porous aeration heads arranged in a planar pattern, with flow-regulating plates on the surface of these aeration heads. A variety of aerator types can be chosen, or even a single integrated aerator can be used. Air is supplied by a fan. The skimmer structure has a high degree of freedom. Structures that can utilize various methods such as gravity flow, siphonage, and suction can be used. The ejector structure provided here can be of the suction type or the siphon type.      There are several types of pinwheel rotors, and one of the more superior types is composed of U-shaped wire loops with seedlings evenly and densely arranged around the hub. This type of pinwheel seedling has a high density and strong starting rotation capability. The tip of its needle-like element is free, while it is constrained at one end by a hinge support at the hub; it can swing and deform circumferentially, and it can also undergo appropriate rotation and deformation axially.  3 Working principle of the cyclone air flotation separator 1) Cyclone dispersion, mixed mass transfer, centrifugal separation – The pinwheel rotor initiates the cyclone effect. A uniform swirl field can facilitate mass transfer processes such as dispersion, mixing, and stripping; it can also enable chemical reactions, as well as be used for the centrifugal separation of phases. The pinwheel speed is below 200 r/min, with low operating load. 2) Pre-sedimentation of the heavy phase: The mixed liquid flow enters from the center at the bottom of the cyclone chamber; a baffle disc is used to redirect the flow into a radial plane flow, and once it reaches a certain radius, its direction changes to flow upward and toward the center. Some large particles remain at the periphery due to centrifugal force; after accumulating, they slide down along the edge of the guide, and then sink into the slurry hopper through the channels in the shielding plate at the bottom of the swirl chamber. 3) Shear aeration and bubble horizontal transfer: The swirl cross-section cuts the air column overflowing from the aeration head, forming bubbles of a size comparable to that of the micro-pores in the aeration head. The broken bubbles are immediately carried horizontally away as the swirl rotates. 4) Pits concentrate the light phase: The orderly rotation of the pinwheel rotor creates pits on the surface of the mixture. Light-phase particles, air-floating particles, or light-phase liquid are drawn upward by air flotation and toward the center of the concave liquid surface due to centrifugal force, allowing for a greater operating thickness. A small positioning light-phase skimmer is sufficient to carry out the separation of the floated substances. 5) Discharge through an annular decanter: The treated liquid flows out from the top of the circular tank via an annular decanter. 6) The order of liquid inflow and outflow can be reversed, allowing the mixture to flow from top to bottom to complete the mixing process. Operationally, it is also possible to carry out work in batches intermittently or by varying the rotor speed.