Paper Title
Leached Heavy Metals from End-of-Life Thin Film Solar Photovoltaics

Abstract
The end of life photovoltaic (PV) panels arenormally disposed of in a landfill, contributingtothe spread of heavy metal contamination into the environment. In this research, three types of thin film PVs including a-Si, CIGS, and CdTewere conducted in the aging process. The heavy metal leaching from thin film PVswasinvestigated including Al, Ag, Cd, Cu, Cr, Fe, Ga, In, Mo, Ni, Pb, Se, Te, As, Mn, and Znfollowingthe toxicity characteristic leaching procedure (TCLP) and the synthetic precipitation leaching procedure (SPLP).In addition, the total concentration of hazardous substances (TTLC) was determined according to the announcement of the Ministry of Industry of Thailand regarding the disposal of waste or unused materials (2023). The leaching result from the TCLP method found that Cd in the CdTe panel had a value of 1.1237 mg/l, significantly higher than the other two types of panels and the only one exceeding the TCLP standard. The SPLP test revealed that the concentrations of heavy metals were similar to the TCLP method but generally in lower amounts.The results of metal concentrations from the SPLP method were compared with the international drinking water standards of the US EPA. It was found that Cd (0.0366 mg/l) in the CdTe panel exceeded the standard limit. Ni (0.1125 mg/l) in the a-Si panel exceeded the standard limit. And Se (0.1342 mg/l) in the CIGS panel exceeded the standard limit.According to the announcement of the Ministry of Industry,TTLC found the a-Si panel had a Ni content (9,521.67 mg/kg) exceeding the limit. The CIGS panel had Cr (1,300.80 mg/kg), Cu (18,526.67 mg/kg), and Se (2,665.33 mg/kg) exceeding the limits. The CdTe panel had a Cd content (502.80 mg/kg) exceeding the limit.Consequently, all three types of panels were identified as hazardous waste, requiring proper disposal methods. Keywords - A-Si, CIGS,CdTe, Simulated leaching, TCLP, SPLP