PAM in Book printing wastewater treatment

Book printing wastewater primarily comes from cleaning printing plates, ink pans, and other equipment during the printing process, as well as cleaning the workshop floor. The wastewater contains pollutants such as water-based inks, making its treatment an important environmental consideration for printing companies.

• Characteristics of book printing wastewater

The characteristics of book printing wastewater primarily stem from the use of water-based inks and other printing-related chemicals. Here are the key features:

1) Complex Composition‌: Book printing wastewater is a complicated mixture of chemical compounds, including colorants (dyes and pigments), binders, and additives from water-based inks‌

2) High pH and Poor Biodegradability‌: Similar to general printing and dyeing wastewater, it often exhibits high alkalinity and low biodegradability due to the presence of synthetic polymers and stabilizers‌

3) Emerging Contaminants‌: It may contain hazardous pollutants such as organohalides (from ink additives) and trace pharmaceuticals (e.g., antimicrobials), which are challenging to remove with conventional treatment methods‌

4) High Water Volume‌: The process generates significant wastewater volumes, necessitating efficient treatment technologies like membrane filtration (e.g., UF/FO systems) for resource recovery‌

• Polyacrylamide Mechanisms

Polyacrylamide (PAM) is widely used in printing wastewater treatment as a flocculant or coagulant to remove suspended solids, turbidity, and organic pollutants‌. Its application varies based on the type of PAM (nonionic, cationic, or anionic) and the specific characteristics of the wastewater‌.

• Cationic PAM (CPAM) is particularly effective for treating negatively charged dissolved organic matter, such as humic substances wastewater, by enhancing flocculation and sedimentation‌.
• Cross-linked PAM has shown superior performance in coagulating solid particles, achieving over 90% water recovery with less than one minute of settling time‌.

• Environmental Considerations‌

PAM degradation in environmental systems (e.g., chemical, biological processes) and potential toxicity post-release require attention to mitigate ecological risks‌.

Integrating PAM with advanced methods (e.g., microalgae bioremediation for starch wastewater‌) or hybrid systems (e.g., carbon steel/activated carbon reactors) could enhance sustainability and resource recovery in printing wastewater treatment.