Silver is one of the valuable materials exist freely on earth crust. Worldwide, massive demand in different purpose makes silver very valuable. On information nearly twenty percent of silver were collected from non-ferrous metallurgical industry, locally generated scrap and photographic film. The toxicity of silver directly impact on surface and ground ecosystem. So it's compulsory to treat and recycle silver from waste material. To fulfil the demand of silver from waste, an enzyme from pineapple make of use. The aim of research work is to recover the silver metal from waste X-ray film by bromelain enzyme as biocatalyst. Response surface methodology full factorial design was used to optimize three operating parameters for maximum recovery of silver. The result shows silver recovery increases with increase in protein concentration, 5.4 mg of pure silver can be recovered from 600 mg of waste X-rays film at most favourable condition of protein concentration 0.2857 mg/ml; temperature 45 °C, pH6.5 and stripping time 20 min. At same optimised parameters, papain biocatalyst shows 4.8 mg and sodium hydroxide shows 5.2 mg recovery of pure silver. The obtained silver powder (grain) having 91.12% purity and total silver recovered.

银是在地壳中自由存在的有价值的材料之一。在世界范围内，出于不同目的的大量需求使白银非常有价值。根据信息，有近百分之二十的银是从有色冶金工业，当地产生的废料和照相胶片中收集的。银的毒性直接影响地表和地面生态系统。因此，必须处理和回收废料中的银。为了满足废物中银的需求，利用了菠萝中的一种酶。研究工作的目的是通过菠萝蛋白酶作为生物催化剂从X线废胶片中回收银金属。响应面方法全析因设计用于优化三个操作参数，以最大程度地回收银。结果表明银回收率随蛋白质浓度的增加而增加，5。在最有利的蛋白质浓度为0.2857 mg / ml的条件下，可以从600 mg废X射线胶片中回收4 mg纯银。温度45°C，pH6.5，剥离时间20分钟。在相同的优化参数下，木瓜蛋白酶生物催化剂显示出4.8 mg，氢氧化钠显示出5.2 mg的纯银回收率。得到的银粉（晶粒）的纯度为91.12％，回收了总银。