国产精品伦一区二区丨最新版天堂资源中文官网丨久久人人妻人人做人人爽丨国产欧美国日产在线播放丨成人免费网站www网站高清丨久99综合婷婷丨日韩麻豆视频丨男男成人高潮片免费网站丨国产精品国产片丨日本无码人妻波多野结衣丨深爱综合网丨av毛片网丨国产精品入口尤物丨天天看夜夜丨黑人精品欧美一区二区蜜桃丨亚洲国产一区精品丨亚洲成色在线丨忘忧草社区www资源在线丨4567少妇伦理丨jzzjzzjzz亚洲成熟少妇

Solution for heavy metal wastewater

Heavy metal wastewater generally comes from industries such as mining, metal smelting and processing, electroplating, leather making, pesticides, papermaking, painting, printing and dyeing, nuclear technology, and petrochemicals. Heavy metals are difficult to biodegrade and are easily absorbed and enriched by organisms. Their toxicity is persistent and they are a highly potential hazardous pollutant. The treatment processes for heavy metal wastewater include chemical precipitation, physical adsorption, ion exchange, and phytoremediation. For heavy metal wastewater with high recycling value or concentration, chemical precipitation or membrane method can be used to concentrate and recover the heavy metals.