Method for treating papermaking wastewater

Abstract

The invention discloses a method for treating papermaking wastewater. The method comprises the steps of discharging the papermaking wastewater into a pollution discharge pond for settling, and then discharging the papermaking wastewater into a regulation pond; adding a reducing agent namely sodium sulfite, settling, and then discharging an upper aqueous solution into a mechanical speed-up clarifying pond with a stirring machine; adding flocculating agents namely basic aluminum chloride and polyacrylamide to separate colloidal substances in the solution, and filtering through a pressure filter to generate fore treatment water; discharging the fore treatment water into a reaction tank, and generating fore pretreatment water through a multi-medium filter; treating the fore pretreatment water to obtain reclaimed water; treating the reclaimed water to produce water according with recycling production. By adopting the method provided by the invention, the problem for recycling of the wastewater generated during papermaking is solved, water resources are saved, and the production cost is reduced.

Description

technical field

[0001] The invention relates to a wastewater treatment method, in particular to a papermaking wastewater treatment method. Background technique

[0002] The waste water produced in papermaking needs to be discharged after reaching the standard. At present, the treatment methods of this kind of waste water include lime milk neutralization and precipitation method. Due to the complex composition of the waste water, it is difficult to treat it. Even if the waste water is treated, all the pollutants in it will reach the national Standards are more difficult; even if the wastewater reaches the standard after treatment, direct discharge is a waste of water resources. Contents of the invention

[0003] The technical problem to be solved by the present invention is to provide a treatment method for papermaking wastewater, the purpose of which is to solve the problem of recycling the wastewater generated in the papermaking process and saving water resources. [000...

Examples

Embodiment 1

[0013] (1) Discharge the production wastewater into the circulating water sewage tank for sedimentation;

[0014] (2) After the precipitation, the water in the upper part is discharged into the adjustment tank, and the reducing agent is added to remove the oxidizing substances in the solution to reduce the damage of the oxidizing substances to the membrane. In the adjusting tank, the pH is first adjusted to about 3 with sulfuric acid, and the reducing agent sodium sulfite is added. Cr 6+ reduced to Cr 3+ , then adjust the pH to 7 with base, Cr 3+ Form Cr(OH) 3 Precipitation, filtered to remove;

[0015] (3) The resulting solution is discharged into a mechanically accelerated sedimentation tank equipped with a stirrer, and a flocculant is added therein to cause coagulation and flocculation of the colloidal material to be separated, filtered through a box filter press, and a flocculant basic Aluminum chloride, add flocculant 3ppm according to the amount of fine suspended sol...

Embodiment 2

[0021] (1) Discharge the production wastewater into the circulating water sewage tank for sedimentation;

[0022] (2) After the precipitation, the water in the upper part is discharged into the adjustment tank, and the reducing agent is added to remove the oxidizing substances in the solution to reduce the damage of the oxidation substances to the membrane. In the adjusting tank, the pH is first adjusted to about 3.5 with sulfuric acid, and the reducing agent sodium sulfite is added. Cr 6+ reduced to Cr 3+ , then adjust the pH to 8 with base, Cr 3+ Form Cr(OH) 3 Precipitation, filtered to remove;

[0023] (3) The resulting solution is discharged into a mechanically accelerated sedimentation tank equipped with a stirrer, and a flocculant is added therein to cause coagulation and flocculation of the colloidal material to be separated, filtered through a box filter press, and a flocculant basic Aluminum chloride, add flocculant 7ppm according to the amount of fine suspended s...

technical field

[0001] The invention relates to a wastewater treatment method, in particular to a papermaking wastewater treatment method. Background technique

[0002] The waste water produced in papermaking needs to be discharged after reaching the standard. At present, the treatment methods of this kind of waste water include lime milk neutralization and precipitation method. Due to the complex composition of the waste water, it is difficult to treat it. Even if the waste water is treated, all the pollutants in it will reach the national Standards are more difficult; even if the wastewater reaches the standard after treatment, direct discharge is a waste of water resources. Contents of the invention

[0003] The technical problem to be solved by the present invention is to provide a treatment method for papermaking wastewater, the purpose of which is to solve the problem of recycling the wastewater generated in the papermaking process and saving water resources. [000...

Examples

Embodiment 1

[0013] (1) Discharge the production wastewater into the circulating water sewage tank for sedimentation;

[0014] (2) After the precipitation, the water in the upper part is discharged into the adjustment tank, and the reducing agent is added to remove the oxidizing substances in the solution to reduce the damage of the oxidizing substances to the membrane. In the adjusting tank, the pH is first adjusted to about 3 with sulfuric acid, and the reducing agent sodium sulfite is added. Cr 6+ reduced to Cr 3+ , then adjust the pH to 7 with base, Cr 3+ Form Cr(OH) 3 Precipitation, filtered to remove;

[0015] (3) The resulting solution is discharged into a mechanically accelerated sedimentation tank equipped with a stirrer, and a flocculant is added therein to cause coagulation and flocculation of the colloidal material to be separated, filtered through a box filter press, and a flocculant basic Aluminum chloride, add flocculant 3ppm according to the amount of fine suspended sol...

Embodiment 2

[0021] (1) Discharge the production wastewater into the circulating water sewage tank for sedimentation;

[0022] (2) After the precipitation, the water in the upper part is discharged into the adjustment tank, and the reducing agent is added to remove the oxidizing substances in the solution to reduce the damage of the oxidation substances to the membrane. In the adjusting tank, the pH is first adjusted to about 3.5 with sulfuric acid, and the reducing agent sodium sulfite is added. Cr 6+ reduced to Cr 3+ , then adjust the pH to 8 with base, Cr 3+ Form Cr(OH) 3 Precipitation, filtered to remove;

[0023] (3) The resulting solution is discharged into a mechanically accelerated sedimentation tank equipped with a stirrer, and a flocculant is added therein to cause coagulation and flocculation of the colloidal material to be separated, filtered through a box filter press, and a flocculant basic Aluminum chloride, add flocculant 7ppm according to the amount of fine suspended s...