Wastewater Treatment Overview   At present, when you plan to build an LFP cathode precursor pilot plant or commercial plant. The wastewater process is hard to bypass. The production process of iron phosphate is mainly based on the iron route in China, among which the sodium process method accounts for 15.75%, the ammonia process method accounts for 69.46%, and the iron dissolve process method accounts for 14.8%. The sodium process mainly uses ferrous sulfate heptahydrate as t