RESEARCH ARTICLE Enhanced flocculation activity of polyacrylamide‐based flocculant for purification of industrial wastewater Mahran Daifa | Eliyahu Shmoeli | Abraham J. Domb Institute of Drug Research, School of Pharmacy‐Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel Correspondence Abraham J. Domb, Institute of Drug Research, School of Pharmacy‐Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel. Email: avid@ekmd.huji.ac.il The flocculation activity of commercially available anionic poly (acrylamide‐co‐acrylic acid), p (AAm‐co‐AA) has been significantly improved, without any inorganic coagulant aid. The effect of three types of surfactants, anionic sodium lauryl ether sulfate (SLES) (Palm Epimen), nonionic cocamide DEA, zwitterionic amphoteric Amphotensid B5, and one organic cation, trimethylammonium bromide (TAB) on coagulation/flocculation performance have been investigated. The performance has been analysed in terms of turbidity, total suspended solid (TSS), total iron (TI) content, and BTEX for treating two kinds of industrial wastewater, produced water (PW) and starch water. We have shown that adding a small amount of each of the studied surfactants, and especially cationic TAB, significantly increases the coagulation/flocculation performance without modifying pH levels. A combination of low dosage of flocculant (310 ppb) and TAB (310 ppb), after 5 minutes, presented 88%, 81%, and 62% reduction in turbidity, TSS, and TI content, respectively, whereas by using 5 ppm of flocculant alone (16 times more), only 76%, 75%, and 43% removal was obtained. The results reveal that TAB performs as an efficient coagulant booster. Compared with regular inorganic coagulants, it is more cost‐effective, reduces the consumption of treatment chemicals, and the pH‐ dependency of contaminants removal. KEYWORDS flocculation, industrial wastewater, iron removal, polyacrylamide, polymer‐surfactant complexes, TSS 1 | INTRODUCTION Treatment of industrial wastewater generated from different industries is a leading global concern. Regulations, meanwhile, have become increasingly stringent, inducing private companies to invest in improved wastewater management. Coagulation‐flocculation is considered among the most important and innovative pretreatment methods of wastewater treatment technologies because of its efficiency in the removal of various pollutants and contaminants in addition to necessary cost‐effectiveness. 1-6 Numerous inorganic coagulants—such as alumi- num and iron salts—as well as organic flocculants such as cationic and anionic polyacrylamide, have been developed as industrial wastewater coagulants. The positively charged Al 3+ and Fe 3+ inorganic ionic coagu- lants interact with the negatively charged colloids, forming suspended solids, ie, micro‐floccs. However, the floccs produced by only coagula- tion are frail and reversible. Hence, a combination of flocculants with coagulants is a common strategy to increase stability of floccs. 7-10 The application of coagulation‐flocculation in wastewater is limited because of environmental and health concerns, since the sludge gen- erated from inorganic coagulants is toxic, produced in large quantities, significantly affects the pH of the treated water. The added aluminum that remains in the wastewater, pollutes the water and endangers the population with Alzheimer's disease–related aluminum neurotoxic- ity. 11-15 Accordingly, the choice of appropriate coagulants is critical and even the use of the traditional coagulants is uncertain. Moreover, despite the increasing application of water‐soluble polymers as floccu- lants in wastewater treatment, they remain much more expensive than inorganic coagulants, therefore limiting application. Furthermore, Received: 15 March 2019 Revised: 7 July 2019 Accepted: 9 July 2019 DOI: 10.1002/pat.4730 Polym Adv Technol. 2019;1–11. © 2019 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/pat 1