Wastewater treatment method after water-based ink printing

Date: Sep 25 2024 From: Star Color

Water based ink printing, as an environmentally friendly printing method, occupies an important position in the modern printing industry. However, the accompanying sewage treatment issues cannot be ignored.

Water based ink printing wastewater has the characteristics of weak alkalinity, high concentration, high chromaticity, and difficult biodegradation, making its treatment difficult. Effectively treating these wastewater not only complies with environmental regulations, but also serves as an important guarantee for the sustainable development of enterprises. This article will provide a detailed introduction to several common and effective methods for treating water-based ink printing wastewater.

Characteristics of water-based ink printing wastewater

The wastewater from water-based ink printing mainly contains water-based ink, starch, surfactants, and other additives. These components make the wastewater exhibit high chromaticity, high COD (chemical oxygen demand), and difficult to degrade characteristics. Therefore, corresponding treatment plans need to be developed for these characteristics during the processing.
Wastewater treatment method after water-based ink printing

Wastewater treatment method after water-based ink printing

Common methods for treating water-based ink printing wastewater

1. Chemical oxidation coagulation process
The chemical oxidation coagulation process involves adding oxidants and coagulants to oxidize organic matter in wastewater and form flocs, which facilitates subsequent treatment. Research has shown that when the optimal oxidant NaClO (15g/L) and the optimal coagulant FCH (30.2g/L) are added to the raw water and the pH is adjusted to 8.5, the COD removal rate can reach 94% and the chromaticity removal rate can reach 100%.

2. Ultrafiltration technology
Ultrafiltration technology utilizes the high-precision filtration performance of ultrafiltration membranes to separate dissolved solids, ions, and particulate matter from wastewater. After treatment with three sets of ultrafiltration components, the COD removal rate of wastewater can reach 92%, but it should be noted that soluble pollutants cannot be completely removed by ultrafiltration technology.

3. Iron chip microelectrolysis process
The iron chip microelectrolysis process improves the biodegradability of wastewater by adjusting the pH value of the wastewater and utilizing the oxidation-reduction reaction between iron chips and coke. Under the optimal process conditions (pH value of 4.0, iron chip content of 10%, coke content of 16.67% of the filler, reaction time of 60 minutes), the COD removal rate of wastewater can reach 85%, and the chromaticity removal rate can reach 95%.

4. Chemical coagulation process
The chemical coagulation process involves adding coagulants and coagulants to form flocs and settle suspended solids and colloidal particles in wastewater. Research has shown that under room temperature conditions, FeCl3 · 6H2O is selected as the optimal flocculant with a dosage of 80mg/L, an optimal coagulation pH value of 4.0, and chitosan as the optimal coagulant aid. When the dosage is 0.8mg/L, the COD removal rate of wastewater can reach 87%, and the chromaticity removal rate can reach 99%.

5. Combination process of coagulation air flotation microelectrolysis SBR
This process combines the advantages of three technologies: coagulation air flotation, microelectrolysis, and SBR (sequencing batch reactor). Firstly, most suspended solids and organic matter are removed through coagulation air flotation treatment; Then use microelectrolysis technology to improve the biodegradability of wastewater; Finally, the organic matter is further degraded through the SBR process. The treatment effect of this process is significant, and the final effluent COD can be reduced to below 71.9mg/L, with a removal rate of up to 97.4% and a chromaticity removal rate of 98%.

The treatment of water-based ink printing wastewater is a complex and important environmental issue. By selecting appropriate treatment methods and technical parameters, the COD and chromaticity indicators of wastewater can be effectively reduced, achieving standard discharge of wastewater.

The above is the treatment method for water-based ink printing wastewater. If you have any questions, please contact us.