| 摘要 |
<p>A wastewater treatment method for reusing the hardness causing material removed wastewater as process water by economically removing hardness causing materials such as organic matters and calcium ions contained in wastewater generated from a paper mill is provided. A method for treating wastewater of a paper mill comprises: (a) an anaerobic treatment step of decomposing organic matters into carbon dioxide and methane gas by anaerobic microorganisms, and reducing sulfuric acid ions into hydrogen sulfide by sulfate reducing bacteria to remove the organic matters; (b) a hardness causing material removal step of dropping effluent of the step(a) using potential energy so as to strip carbon dioxide, converting hardness causing materials into insoluble solids, and crystallizing the insoluble solids on the surface of a plastic or ceramic media so as to remove the insoluble solids; and (c) a suspended solid removal step of injecting a coagulant into effluent of the step(b) to remove the suspended solids by settling or floating suspended solids.</p> |
