Assessment of Microplastic Contamination in Drinking Water from an Italian Plant: An Analytical Study

In this work, microplastics in drinking water from a water treatment plant were analyzed. The plant treats surface water from a River in the north of Italy. River water is utilized to supplement groundwater as drinking water during periods of high demand when groundwater alone is insufficient to meet the needs of the population. The water that enters the plant is turbid and rich in inert or organic impurities and undergoes chemically and physically treatments, including sedimentation, flocculation and clarification, sand filtration, adsorption on activated carbon and disinfection. The water at the outlet of the plant was collected by plant technicians at two sampling points and was collected in dark glass bottles with a volume of 1 or 2.5 liters. A hydrogen peroxide (30 %v/v) solution was added to all the samples at a concentration of 10 ml/l. The sampled water volumes were filtered on silicon filters (MakroPorP12M5-500) of 13 mm diameter, with pore size of 5-6 μm. All the collected particles were analysed by using Micro-FTIR (Thermo Scientific™ Nicolet™ iN™10 Infrared Microscope) in the range 4000-675 cm-1 with resolution of 4 cm-1. The entire filter surface was scanned, and the particles were counted, identified and measured by using Omnic Picta software. The results showed the main presence of polyolefins (PP and PE) and smaller amounts of polyamides (PA) and polyvinyl chloride (PVC). However, the main result was the high variability of microplastic fragments in the analyzed samples with the number of particles ranging between less than 10 to about 100 per liter, thus confirming literature data concerning water for human consumption