Electroplating wastewater treatment sedimentation tank

Electroplating wastewater treatment sedimentation tankThe main function of is to remove suspended solids, heavy metal ions, and some organic matter from sewage, and achieve water purification through gravity precipitation or coagulation precipitation, reducing the load for subsequent treatment.

core functionality

Removing suspended solids: By gravity, particles are settled to reduce the turbidity of wastewater. ‌

Preliminary separation of heavy metals: can intercept some heavy metal ions (such as copper, nickel, etc.), reducing the difficulty of subsequent treatment. ‌

Reduce organic load: Coagulation precipitation can improve the removal efficiency of recalcitrant organic matter. ‌

Typical application scenarios

Primary sedimentation tank: set before biological treatment to reduce suspended solids content. ‌

Secondary sedimentation tank: set up after biological treatment to separate activated sludge. ‌

Chemical sedimentation tank: adding coagulants to enhance the removal of color, oil, etc. ‌

Design Key Points

Horizontal sedimentation tank: aspect ratio ≥ 4:1, effective water depth ≤ 3m, maximum flow velocity ≤ 7mm/s (primary sedimentation) or 5mm/s (secondary sedimentation). ‌

Vertical flow sedimentation tank: diameter ≤ 7m, upward flow velocity 0.5-1.0m/s, sludge hopper inclination angle 45 ° -60 °. ‌

Radial flow sedimentation tank: diameter ≥ 16m, scraper line speed ≤ 3m/min.

Electroplating wastewater treatment sedimentation tankIt is mainly used to remove suspended solids, heavy metal ions, and organic pollutants from wastewater, and is one of the key steps in the treatment of electroplating wastewater. Its functions include physical separation, chemical precipitation, and auxiliary treatment.

Core function: Separate suspended solids from heavy metals

Physical sedimentation: By gravity, suspended particles with a density greater than water (such as metal oxides and colloidal particles) settle to the bottom of the pool, forming sediment. ‌

Chemical precipitation: Adding coagulants (such as polyaluminum chloride) or sulfides to the chemical precipitation tank to generate insoluble precipitates of soluble heavy metals (such as copper and chromium), facilitating subsequent solid-liquid separation. ‌

Specific application scenarios

Chromium containing wastewater treatment: First, reduce hexavalent chromium to trivalent chromium, and then generate chromium hydroxide precipitate through a chemical precipitation tank. ‌

Coking copper wastewater treatment: After destroying the complexed copper ions, copper sulfide or copper hydroxide precipitation is formed through a chemical precipitation tank. ‌

Industrial wastewater pretreatment: removing suspended solids, oil stains, etc., and reducing the load of subsequent membrane separation or ion exchange processes. ‌

auxiliary role

Adjust water quality: Buffer the inflow fluctuations through the sedimentation tank volume to stabilize the water quality conditions for subsequent treatment processes. ‌

Reduce pollutant concentration: Some organic matter and nutrients are discharged with the sediment, indirectly reducing the residue of heavy metals or organic matter.