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(PFCs; a subset of PFAS) under the Third Unregulated Contaminant Monitoring Rule (UCMR 3) [40]. 159

PFOA, PFOS, perfluoronanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), 160
perfluoroheptonic acid (PFHpA), and perfluorobutanesulfonic acid (PFBS) were all on the UCMR 3 161

list in May 2012. It is important to note that various manufacturing sectors use thousands of different 162
PFAS. As a result, a more chemically comprehensive environmental assessment of the extent and 163

magnitude of PFAS contamination than that initiated under UCMR 3 may be required in some cases 164

[41]. There is a considerable likelihood that PFAS-related environmental claims will rise in the coming 165
years due to the widespread geographic occurrence, the vast number of potential contributors, and the 166

number of persons exposed to damaged water sources [42]. The production, distribution, use, disposal, 167
and recycling of chemicals as well as the manufacturing, usage, and disposal of the items that contain 168

them can all result in environmental and human exposure to PFAS. Nearly all persons living in the 169
United States (US), Europe, and other nations across the world have been shown to have a significant 170

amount of PFAS in their bodies, notably PFAA (Perfluorinated Alkyl Acids) [43]. According to reports, 171

the Arctic atmosphere contains FTOHs and FSAs (fluorosulfonamido alcohol) at levels that are roughly 172
five times lower than those seen in urban areas. 173

Some short-chain PFAS bioaccumulate in humans, and animal studies on fish suggest that they can do 174

this in the long-chain chemicals they wanted to replace in excess [44]. The concentrations of short chain 175
PFAS, such as perfluorobutanoic acid (PFBA), perfluorobutanesulfonic acid (PFBS), and 176

perfluorohexanoic acid (PFHxA), have increased in environmental media because short-chain PFAS 177
have largely replaced long-chain PFAS in society [45]. PFAS have a high level of persistence, which 178

causes long-term build up in the environment and in living things, increasing the risk of injury. Recent 179
widespread detection of several replacement PFAS in groundwater and surface water, including PFBA, 180

PFBS, and GenX, is a major cause for worry [46]. Growing in polluted soil or using contaminated water 181

for irrigation can cause PFAS to accumulate in plants, particularly food crops [47]. Top predators (such 182
as whales, bald eagles, and humans) have the highest amounts of bioaccumulation as it moves up the 183
food chain. 184

3. Methods to remove PFAS from wastewater 185

PFAS can now be removed from wastewater in three different methods. These include Reverse 186
Osmosis (RO), high-pressure membrane filtration of nano filtration, Granular Activated Carbon (GAC), 187

and Ion-Exchange resins (IXR). The application of these methods, however, is dependent on the 188
properties of the wastewater and the type of PFAS present. 189

3.1 Granular Activated Carbon 190