The category and nature of wastewater are very complex. The treatment requirements are different. So, it is necessary to combine several treatment methods |(or unit technology) and reasonably set the primary and secondary relation and sequence so as to form an integral whole and efficiently and economically realize the treatment task. The entirety consisting of several unit processes is called wastewater energy saving treatment system. To show the treatment with the graphics is called as the processing system chart or process flow chart.

The wastewater energy saving treatment system consists of several treatment series. The treatment series are the sequence combined with a kind or several kinds to realize some special treatment target. The treatment target includes several classification methods. The treatment target are often confirmed for the wastewater treatment based on the size, nature (called grain gradation) of removed particle. Based on the division of the treatment target, the mine wastewater treatment system can be divided into the following 4 kinds including the treatment of sludge:
(1) Granular matter removal serial. The method includes the sieving method and gravity separation method.
(2) Suspended particle and colloidal removal series. The method includes the concentration, clarification and coagulating sedimentation.
(3) Dissolved matter removal series. There are many kinds of treatment methods including various chemical sedimentation method, adsorption method, ion exchange method, membrane separation method and extraction method.
(4) sludge treatment series. The method includes the concentration, hydration (filtering) and drying.