Table 2: Applications of various hydrogels in wastewater treatment.

Hydrogel	Application
Polyacrylamide	Used as flocculants or coagulants in industrial wastewater treatment [68].
Guar gum	Used to reduce raw water turbidity from 26.5 to 1.0 [69].
Gum tragacanth	Used as an emulsifier, thickener, and binder in industries [70].
Gum Arabic	Used to reduce the high concentration of alum needed for water treatment [71].
Gum ghatti	Widely used as adsorbents for removing different impurities from wastewater, like synthetic dyes and toxic heavy metal cations [72].
Xanthan gum	Used as a novel flocculant [73].
Alginate	Used as a physical barrier against native microorganisms in wastewater [74].
Chitosan	Used for the heavy metals and dyes adsorption [75].