Process for recovering chromium in chrome tanned leather waste water

A waste water and chrome tanning technology, applied in water/sewage multi-stage treatment, water/sludge/sewage treatment, chemical instruments and methods, etc., can solve the problems of low reuse value of chrome sludge and high total chromium content in discharged waste water, etc. Accelerate the sedimentation speed, reduce the sedimentation volume, and ensure the effect of the reaction

Active Publication Date: 2013-07-10
BROTHER ENTERPRISES HLDG CO LTD
View PDF3 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem of low reuse value of chrome sludge after treatment of general chrome tanning wastewater and high total chromium content in discharged wastewater, and to provide a method that is beneficial to the subsequent reuse of chrome sludge and the realization of total chromium in wastewater after chromium recovery. Chromium recovery process with up-to-standard discharge

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Process for recovering chromium in chrome tanned leather waste water
  • Process for recovering chromium in chrome tanned leather waste water

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] A diversion device is installed at the tanning drum in the tanning workshop, and the chrome tanning wastewater is collected separately and passed through the mechanical grille 1 with a grid gap of 1 mm to remove large pieces of dander and other large particles of impurities, and then enters the chrome tanning wastewater collection pool 2; Wastewater such as ash, softening and degreasing enters the comprehensive wastewater collection pool. The chrome tanning waste water in the collection pool 2 is pumped into the chamber filter press 4 adopting 200 mesh polyester filter cloth to filter through the diaphragm pump A3, and after further removing the fine particle impurities such as hair slag, fine dander and sawdust in the chrome tanning waste water, Enter the reaction pool 5. When the liquid level in the reaction tank 5 reaches the specified level, turn on the mechanical stirring, control the temperature of the chrome tanning wastewater in the reaction tank 5 at 25°C, then...

Embodiment 2

[0024] A diversion device is installed at the tanning drum in the tanning workshop, and the chrome tanning wastewater is collected separately and passed through the mechanical grille 1 with a grid gap of 1 mm to remove large pieces of dander and other large particles of impurities, and then enters the chrome tanning wastewater collection pool 2; Wastewater such as ash, softening and degreasing enters the comprehensive wastewater collection pool. The chrome tanning waste water in the collection pool 2 is pumped into the chamber filter press 4 adopting 200 mesh polyester filter cloth to filter through the diaphragm pump A3, and after further removing the fine particle impurities such as hair slag, fine dander and sawdust in the chrome tanning waste water, Enter the reaction pool 5. When the liquid level in the reaction tank 5 reaches the specified level, start the mechanical stirring, control the temperature of the chrome tanning wastewater in the reaction tank 5 at 40°C, then s...

Embodiment 3

[0026] A diversion device is installed at the tanning drum in the tanning workshop, and the chrome tanning wastewater is collected separately and passed through the mechanical grille 1 with a grid gap of 1 mm to remove large pieces of dander and other large particles of impurities, and then enters the chrome tanning wastewater collection pool 2; Wastewater such as ash, softening and degreasing enters the comprehensive wastewater collection pool. The chrome tanning waste water in the collection pool 2 is pumped into the chamber filter press 4 adopting 200 mesh polyester filter cloth to filter through the diaphragm pump A3, and after further removing the fine particle impurities such as hair slag, fine dander and sawdust in the chrome tanning waste water, Enter the pre-mixing zone 5 of the reaction pool. Turn on the mechanical agitation in the pre-mixing zone 5 of the reaction pool, control the temperature of the chrome tanning wastewater at 25°C, then slowly add 30% aqueous sod...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a process for recovering chromium in chrome tanned leather waste water. The invention is characterized in that the process for recovering chromium in chrome tanned leather waste water is in favor of subsequent reutilization of chromium mud and realization of standard discharge of total chromium content in waste water after recovering chromium, the chrome tanned leather waste water is effectively split and individually collected. The method comprises a first filtration by using 1-3mm grid, a secondary filtration by using a filter press, a third filtration by employing a reaction for controlling the pH value of temperature and reusing the filter press for press filtration. The content of the obtained filter residue which is chromium oxide of the chromium mud is great than 8wt%, and the content of filtrate which is the total chromium content of the discharged waste water is less than or equal to 1.5mg / L by referring Cr.

Description

technical field [0001] The invention belongs to the clean production technology in the tanning industry, in particular to a method for recovering chromium in the chrome tanning wastewater of the tanning industry. Background technique [0002] At this stage, tanneries generally use simple alkali precipitation to treat chrome tanning wastewater, and the resulting precipitate is chromium-containing sludge, referred to as "chrome sludge". This chromium sludge has many impurities, low chromium content, and low reuse value. The disposal methods adopted by enterprises are basically incineration or landfill, but these two methods not only waste resources but also have hidden dangers of secondary pollution. On the other hand, the total chromium content in the discharged wastewater after chrome tanning wastewater treatment is difficult to meet the discharge standard, usually exceeding 50mg / L, which affects the subsequent biochemical treatment of comprehensive wastewater. [0003] Fr...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & AuthorityPatents(China)
IPC IPC(8): C02F9/04
Inventor周中平张文黄志强
OwnerBROTHER ENTERPRISES HLDG CO LTD