Method for improving sludge settling performance in low-concentration zinc-containing wastewater treatment process

A technology for wastewater treatment and sludge settling, applied in the field of environmental engineering, can solve problems such as poor settling performance and small sludge size, and achieve the effects of improving settling compression performance, simple equipment and improving sludge settling performance.

Active Publication Date: 2016-06-29
CENT SOUTH UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, although low-concentration zinc-containing wastewater (<100mg / L) will reduce the supersaturation of the solution, the sludge formed is very small in size, usually at the millimeter level or lower. If the sludge structure is flocculent, it will Settling properties under the action will be poor

Method used

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  • Method for improving sludge settling performance in low-concentration zinc-containing wastewater treatment process
  • Method for improving sludge settling performance in low-concentration zinc-containing wastewater treatment process
  • Method for improving sludge settling performance in low-concentration zinc-containing wastewater treatment process

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Embodiment 1

[0021] The 1000mL reaction beaker was placed on a constant temperature magnetic stirring device, the temperature was controlled at 25°C, and the stirring rate was adjusted to 200rpm. 100 mL of the suspension containing ZnO nanoparticles (2.5 g / L) was added to the reaction beaker. Then drop sodium hydroxide solution (0.03mol / L) and low-concentration zinc-containing waste water (zinc ion concentration 50mg / L) respectively in the beaker simultaneously, control the drop rate rate of low-concentration zinc-containing waste water to be 3.5mL / min, by The sodium hydroxide solution controls the reaction pH value to 9.0±0.2, and reacts for 1 hour. A 0.1% polyacrylamide (PAM) flocculant was added to the suspended solution system after the above reaction to make the reaction concentration 15 mg / L. Then stir rapidly (500rpm) for 30s, and then stir slowly (50rpm) for 15min. Stand still for 30 minutes to stabilize and completely settle the sludge. The removal rate of zinc ions in this pro...

Embodiment 2

[0023] The 1000mL reaction beaker was placed on a constant temperature magnetic stirring device, the temperature was controlled at 15°C, and the stirring rate was adjusted to 100rpm. Add 100 mL of the ZnO nanoparticle-containing suspension (3.0 g / L) to the reaction beaker. Then drop sodium hydroxide solution (0.05mol / L) and low-concentration zinc-containing wastewater (zinc ion concentration 50mg / L) respectively in the beaker simultaneously, control the dropping rate of low-concentration zinc-containing wastewater to 5mL / min, pass hydrogen The sodium oxide solution controls the reaction pH value to 9.0±0.2, and reacts for 1 hour. A 0.1% polyacrylamide (PAM) flocculant was added to the suspended solution system after the above reaction to make the reaction concentration 15 mg / L. Then stir rapidly (500rpm) for 30s, and then stir slowly (50rpm) for 15min. Stand still for 30 minutes to stabilize and completely settle the sludge. The removal rate of zinc ions in this process is ...

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Abstract

The invention discloses a method for improving sludge settling performance in the low-concentration zinc-containing wastewater treatment process. Chemical settling sludge of low-concentration zinc-containing wastewater is small in size, loose in structure and poor in settling performance, and the settling velocity is usually smaller than 1.0 cm/s. According to the method for improving the sludge settling performance in the low-concentration zinc-containing wastewater treatment process, a seed-crystal inducing concurrent feeding controlled crystallization method and a flocculating method are applied, non-biological particle sludge which is compact in structure is obtained in the low-concentration zinc-containing wastewater chemical settling process, the settling velocity can be increased to 7.3 cm/s, the sludge water content can be reduced to 91%, and the settling and compressing performance of the sludge is significantly improved.

Description

technical field [0001] The invention belongs to the field of environmental engineering, and in particular relates to a method for improving the sedimentation performance of sludge during the treatment of low-concentration zinc-containing wastewater. Background technique [0002] The sludge produced during the chemical precipitation process of low-concentration zinc-containing wastewater is usually very small in size and flocculent in shape. Due to the requirement of liquid separation, the zinc ion concentration and turbidity of the effluent have increased, which is not conducive to the treatment of zinc-containing wastewater. In order to effectively improve the settling performance of zinc-containing wastewater chemical precipitation sludge, Central South University invented a method for forming non-biological granular sludge in the process of heavy metal wastewater treatment (public number: 103288191A; public date: 2013-09-11), The sedimentation performance of sludge can b...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/04
CPCC02F1/56C02F1/66C02F9/00C02F2101/20C02F2301/08
Inventor 柴立元李青竹颜旭叶丽君王庆伟闵小波杨卫春
Owner CENT SOUTH UNIV
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