For iron oxide pigment, it contains tens of kinds colors, such as: Iron red, iron yellow, iron black, iron orange, iron brown, iron green etc... But it will bring large quantity of waste water. Due to the large amount of iron filings, nitric acid and sulfuric acid are used in the producing, the pH value of effluent is very low, namely very acid. And the concentration of “Fe” ions and ammonia nitrogen is very high.
While wastewater treatment, on one hand, the “Fe” ions are easily to be removed. First step, it will adjust the PH value, then oxygenize them via aeration, so that transfer them into Fe(OH)3 and Fe(OH)2, and finally deposit. However, for ammonia-nitrogen wastewater, it is more complicated. But the most economic method is chlorination.
On the other hand, after remove the iron ions, the wastewater will flow into the stripping tower. In here, the free ammonia-nitrogen ions will volatilize and discharge out. Then will add excess amount of chlorine or sodium hypochlorite, so that completely oxygenize the ammonia to nitrogen. This technology is mature and cheap cost. After that, the sewage will be processed by dechlorination and depostion. Finally will be dewatered by a filter press machine. Please contact professional filter press manufacturer for qualified equipment.