Dear Maeve, I have no ...

Dear Maeve,

I have no papers to recommend on this topic but just my own recommendation based on 38 years international expertise in R&D, design and operation of mainly industrial effluent treatment plants (new and retrofit upgrades). The source of a chemical (natural resp. scientific) makes little difference as opposed to the kind of chemicals (class and chemical formula) and the quantities being dosed. We learned that the use of chemicals (different kinds and amounts) can be minimized by replacing physical-chemical treatment by advanced biological treatment starting with anaerobic methanisation where feasible. Most acid organic industrial effluents can be neutralized without chemicals (lye) by biologically converting the organic acids to methane, carbon dioxide and water. In addition, biological adsorption and flocculation can replace conventional (electro-)chemical coagulation and flocculation. Finally heavy metals can be removed by anaerobic biological treatment without any chemicals other than a bit of (waste) organics if not already present in the effluent.