In the proposed method, crude enzymes extracted from waste dry leaves of 15 different plants showing protease activity were used for removal of silver from exposed medical X-ray film by hydrolysis of gelatin. Optimum operating pH and temperature for crude protease extract was found to be 7 and 50 °C, respectively. The X-ray film before and after protease treatment was analysed using FTIR (Fourier-transform infrared spectroscopy) and EDS (Energy-Dispersive X-Ray Spectroscopy). The slurry obtained after smelting process analysed using EDS shows 99.8% of silver recovery. The result confirms that the enzyme extraction process recovers silver and PET (polyethylene terephthalate) in eco-friendly treatment methodology when compared to conventional chemical treatment process.

在所提出的方法中，从具有蛋白酶活性的 15 种不同植物的废弃干叶中提取的粗酶用于通过明胶水解从暴露的医用 X 射线胶片中去除银。发现粗蛋白酶提取物的最佳操作 pH 值和温度分别为 7 和 50 °C。使用 FTIR（傅立叶变换红外光谱）和 EDS（能量色散 X 射线光谱）分析蛋白酶处理前后的 X 射线胶片。使用 EDS 分析冶炼过程后获得的浆料显示 99.8% 的银回收率。结果证实，与传统的化学处理工艺相比，酶提取工艺以环保的处理方法回收银和 PET（聚对苯二甲酸乙二醇酯）。