Answer

River May Water Treatment

Justification  

            Water treatment for drinking requires a comprehensive system. The system becomes even more elaborate when such water could contain industrial effluent. Treatment of such water requires a thorough analysis to check on levels of various contaminants and how best they can be removed to ensure the water is safe for drinking (US EPA, 2019). Normal water treatment plants remove most water contaminants. However, the contaminants of growing concern represent the category which cannot be removed through the contemporary water treatment method (Ma et al., 2012). Instead, additional effort should be made to deal with such components which may have devastating health when ingested by humans and animals. This paper seeks to justify the designed treatment plan for River may remove all waste including the contaminants of growing concern.

            The first steps of water treatment are characteristic of all water treatment systems. Secondary treatment of water through coagulation and flocculation removes sediments from wastewater. Such sediments include solid particles such as soil and industrial wastes. Advanced treatment, on the other hand, comprises of various processes which assist remove other contaminants including contaminants of emerging concern from wastewater to make it safe for drinking.

            According to Furlong et al. (2017), there are various treatment plans for dealing with contaminants of emerging concern. For instance, personal care and pharmaceutical products in source and drinking water can be removed through various processes. Personal care and pharmaceutical contaminants of emerging concern such as Ethinyl Estradiol (17-alpha ethynyl estradiol), Erythromycin, Carbamazepine, Bisphenol A, and Diclofenac, can be removed from water through chlorination treatment and oxidation systems. Use of granular activated carbon also removes these pharmaceutical and personal care products up to 99%% (Ma et al., 2012). Reverse osmosis, nanofiltration, and membrane filtration are also used for efficient removal of personal and pharmaceutical products from the water such as erythromycin. All pharmaceuticals at typical 3mg/L dosage can be removed by the chlorination process (Furlong et al., 2017).

Ingestion and skin contact with PAH is found to have carcinogenic effects. Extremely low contents of PAH is required to have a 10^-6 cancer risk level. Exposure to PAH also leads to systemic toxicity and tissue damage. A polycyclic aromatic hydrocarbon (PAH) is removed from the water through aeration of the water. These compounds are hydrophobic hence escape the aerobic wastewater treatment by binding with the sludge. As a result, they are eliminated from the drinking water. In case the contents are still present in drinking water after the aerobic process, anaerobic degradation is used to remove them under methanogenic conditions (Nepis, 2019).

Perfluorooctane sulfonic acid is a man-made chemical present in the environment and used to make consumer products water resistant and non-stick. In many industrial processes,  it is contained in foams used for fire fighting. However,  Perfluorooctane sulfonic acid persists in the environment and bioaccumulates in bodies of animals and humans (US EPA, 2019).  Perfluorooctane sulfonic acid is dissolved in River May’s water which makes it extremely difficult to remove it. The content is removed through high pressure activated carbon absorption and ion exchange. Activated carbon treatment is used to adsorb synthetic organize chemicals, taste and odor compounds, and natural organic compounds in treatment systems for drinking water. Adsorption is a chemical and physical process where substances are accumulated at the solid and liquid interface. The highly porous activated carbon material with coal, lignite and wood contents is very efficient in removing the  Perfluorooctane sulfonic acid contents from the water (Nepis, 2019). The carbon can be in the form of a powder or granular activated carbon.

Ion exchange treatment, on the other hand, utilizes a polymeric highly porous material which is insoluble in water, acid, and base. Hydrocarbons are used to make the tiny beads comprising the resin. Ion exchange resins can be anionic or cationic are used to remove negatively and positively charged ions of Perfluorooctane sulfonic acid (PFOS)  and 1,4-Dioxane from the water by attracting them (Nepis, 2019). This technology is highly efficient because resin regeneration is not needed hence there are no contaminants requiring disposal, treatment and special handling (Ma et al., 2012).

High-pressure membranes such as reverse osmosis and nanofiltration also remove Perfluorooctane sulfonic acid (PFOS), pharmaceuticals and personal care products. High-pressure membranes are dependent on the permeability of the membrane. A nanofiltration membrane has a high rejection degree to hardness while reverse osmosis membranes have high rejection degrees to all salts. Therefore, nanofiltration removes particles while the reverse osmosis removes minerals (Furlong et al., 2017).

In conclusion, water treatment disinfectants such as UV, monochloramine, activated charcoal, free chlorine, and ozone can remove pharmaceutical and personal care contaminants of emerging concern from River May. High pressure membrane processes such as nanofiltration and reverse osmosis activated carbon, and ion exchange is used to remove Perfluorooctane sulfonic acid, 1,4-Dioxane, pharmaceuticals and personal care products from the river. Removing all contaminants of emerging concern from River May using a single process requires research and invention.