Normally physical-chemical systems are used for industrial effluents purification
Industrial effluents purification
The continuous chemical-physical treatment consists in purifying different types of effluents, at a constant flow rate for optimal purification efficiency. A typical purification cycle may include, but is not limited to, the following phases: Diluted exhaut storage and redelivery from continuous washing The washings coming from the various processes flow into a collection tank. From here the water are taken up by an electric pump and sent to the first mixing reactor EXHAUSTED CONCENTRATES STORAGE AND REDELIVETY Discontinuous wastewater coming from occasional drains of concentrated baths, from demineralization eluates or from specific upstream pre-treatments flow into a collection tank. From the tank the water is taken and sent, only in the presence of the primary flow of the washing, to the first mixing reactor. pH AUTOMATIC CONTROL/COAGULATION TREATMENT The water flows into the first mixing reactor to homogenize the various types of waste water and added reagents, such as e.g. coagulants, products for pH control, etc. SLUDGE THICKENING TREATMENT The waste water from the previous treatment is fed to a reactor with an electric mixer to keep the solution homogeneous, favoring the aggregation of sludge flakes, thanks to the dosing of specific flocculating products. SLUDGE SEDIMENTATION TREATMENT From the reactor the flakes will flow into the sludge settling section. The clarified water, through a spillway, flow into the redelivery tank while the separated sludge collects on the bottom of the decanter. CLARIFIED EXHAUSTS RECOVERY From the sedimentation treatment the clarified water flows falling into a tank, from which it is taken to be sent to the subsequent post-treatment phases to complete the purification process. Some possible options are listed below: – Quartz filtration The filtration station is necessary to eliminate from treated water the suspended bodies; in this sense mixtures with different grain sizes are used for specific filtering products. – Adsorption on active carbons At the filtration outlet, the water flows into the adsorption section. This section is useful for breaking down traces of residual organic substances such as mineral oils, surfactants and solvents and uses different types of activated carbon with a highly specific surface. – Ph automatic final correction (control) At the end of the post-treatment section, the waste water can flow into the reactor for final correction of the pH value. The pH corrector is dosed to adjust the pH to the correct value foreseen for the final discharge. – Sludge thickness and treatment The sludge accumulated in the lower hopper of the sedimentation tank is sent to the thickening section. From here the sludge is taken and sent to the dehydration section for a significant reduction in volume and consequent savings on disposal costs. The drained water will be sent back by gravity to the storage tank.