无限第一国产资视频在线,亚洲国产视频tv破解版,玉蒲团玉女心经快播,亚洲乱码日产精品M,国产一级高清视频免费看,又粗又硬免费毛片,国产在线精品天海翼在线,国产高跟鞋广告视频播放,激情文学欧美在线,人妻免费福利视频

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.