Material Safety and Integrity of Water-Filled Low-Density Polyethylene Bags in an Accelerated Weathering Investigation for Applications in Solar Water Disinfection (SODIS)

In this work, the potential use of LDPE bags as containers in the SODIS application by simulated in an accelerated weathering tester (QUV), with respect to material safety and durability, was investigated. For the material integrity, a decrease in the elongation at break from 818% (at the beginning) to 21% (after 6 weeks of UV exposure) corresponded to the long UV exposure. A significant degree of mechanical degradation was evident during 2 to 4 weeks of UV exposure. The UV-Vis results showed that the UV transmittance of the bags, mostly in the UV-B region, decreased with longer duration of UV exposure. The FT-IR results showed a slight increase in carbonyl group, particularly observable in the bags exposed under UV for 3 weeks or longer. For the material safety, the amount of plastic additives that were leached into water was negligibily small and much lower than the limit of the safety standard. The results and analyses from this work provide insights into the feasibility of LDPE as an alternative material for SODIS containers and potentially be useful for future designs of SODIS containers to improve the disinfection and durability performances.