Micro sand sedimentation tank

Overview:

The high-efficiency precipitation process of micro-sand weighted flocculation is a treatment technology forwater supply and sewage treatment,mainly used to remove suspended matter,turbidity and granular organic matter in water. In this process,by adding micro-sand,the pollutants are polymerized into large particles that are easy to precipitate under the action of polymer flocculant,thus speeding up the sedimentation rate of pollutants in the sedimentation tank.Combined with the principle of inclined plate sedimentation,the sedimentation area and precipitation time of the sedimentation tank are greatlyreduced,anda good effluent effect can be obtained.The micro-sand sedimentation tank process has been successfully applied for more than ten years,and has a large number of engineering cases,especially for those occasions where thetreatment is difficult and the efluent water quality is high,such as low temperature and turbidity water,large changes in inflow water quality and quantity,high salinity,raw water containing algae,and industrial wastewater containing high chroma and heavy metals.The flocculation can be completed within 10min,and the precipitation of about 20min can obtain good treatment water quality,which is more advantageous for some areas with land shortage.
 

Specific operation:

The raw water or sewage first enters the coagulation tank,and the coagulant (usually aluminum salt or iron salt)can be added to the inlet of the coagulation tank or the water inlet pipe,mixed evenly under the action of the agitator,and then enters the injection tank with micro sand and polymer flocculant.The dynamic mixing of the agitator increases the possibility of contact between the mixture,the polymer and the fine sand.After flocculation,the water enters the maturation tank,and a polymer flocculant dosing pipeline is also provided at the entrance of the tank.The slow mixing process in the maturation tank promotes the maturation of the floc and makes the micro-sand become the core of the newly formed floc.The diameter of the floc after flocculationby micro-sand can reach more than 150um.
Subsequently,the floc containing sand is precipitated at a high speed in the clarified part of the inclined plate,the clarified water is collected by the collecting tank,and the sludge containing micro-sand settles at the bottom of the pool,collected by the mud scraper to the central area of the bottom of the sedimentation tank,and is extracted by the micro-sand circulating pump in a certain proportion,and then through the circulating pipeline to the hydraulic cyclone.Due to the difference in the specific gravity of micro-sand and sludge,the sludge and micro-sand are separated under the action of centrifugal force in the hydrocyclone.Since the hydrocyclone is located at the top of the injection tank,the under flowed sand can be used directly back into the injection tank,while the light sludge and most of the water move upwards together to be discharged from the hydrocyclone in the form of overflow.