Flue gas cleaning solution purification system and method thereof

A flue gas cleaning solution purification system comprising:

• a scrubber configured to remove contaminants from flue gas by using a cleaning solution so as to form a contaminated cleaning solution;
• a cleaning solution purification system comprising a settling tank fluid coupled to the scrubber so as to receive the contaminated cleaning solution therefrom during use, the settling tank configured to separate the contaminated cleaning solution during use into a supernatant water and a sludge obtained by settling of the contaminants contained in the contaminated cleaning solution;
• a cleaning solution resupply line extending from the cleaning solution purification system back to the scrubber;
• a supernatant water storage tank fluid coupled to the settling tank for receiving the supernatant during use;
• a filter configured to filter the supernatant water during use;
• and
• a supernatant water outlet pipe having first end fluid coupled to the supernatant water storage tank and an opposing second end that branches into a first supernatant water outlet branch pipe fluid coupled to the filter and a second supernatant water outlet branch pipe fluid coupled to the cleaning solution purification system or to the cleaning solution resupply line.