Water purification apparatus and method for using pressure filter and pore control fiber filter

A water purification apparatus that uses a pressurized micro-filter preprocessed with a coagulation inclined-plate sedimentation reservoir and a pore-control fiber filter for improvement of a recovery rate, the water purification apparatus comprising:

• a raw water storage reservoir configured to maintain a constant raw water amount by stabilizing the water level of inflow raw water;
• a flash mixer configured to create micro-flocs through electrical neutralization and adsorption by rapidly reacting injected coagulants with pollutants contained in outflow water from the raw water storage reservoir;
• a two-stage coagulation reservoir comprising a first agitator configured to grow the micro-flocs in the outflow water from the flash mixer to flocs with a filterable and sedimentable size;
• an inclined-plate sedimentation reservoir equipped with a fin inclined plate configured to separate by surface loading and by turbulence, to sediment the flocks in the outflow water from the two-stage coagulation reservoir, and to discharge only upper clean water;
• a membrane-filtration inflow raw water reservoir configured to maintain a constant outflow water amount by stabilizing the water level of the outflow water from the inclined-plate sedimentation reservoir;
• a pressurized micro-filter configured to receive/filter the outflow water from the membrane-filtration inflow raw water reservoir, discharge membrane-filtration produced water, and return circulating water to the front end of the flash mixer;
• a backwash water reservoir a configured to maintain an outflow water amount by stabilizing the water level of membrane-filtration produced water from the pressurized micro-filter and provide backwash water to the pressurized micro-filter;
• a processing reservoir configured to discharge the membrane-filtration produced water to a clear well of a water purification plant while maintaining the outflow water amount by stabilizing the water level of the outflow water from the backwash water reservoir;
• a backwash wastewater recovery reservoir configured to recover the backwash wastewater from the pressurized micro-filter and comprising a second agitator configured to prevent the sedimentation of sludge contained in the backwash water;
• a flow channel switch unit configured to selectively supply the backwash water of the backwash wastewater recovery reservoir through first and second pipes according to an external control;
• a pore-control fiber filter configured to receive the backwash wastewater from the backwash wastewater recovery reservoir through the first pipe of the flow channel switch unit, filter the same, and return the fiber-filtration water to the front end of the flash mixer;
• a discharge sludge wastewater reservoir configured to discharge the backwash wastewater from the pore-control fiber filter and the discharge sludge from the inclined-plate sedimentation reservoir;
• and
• a control panel configured to control the flow channel switch unit according to the raw water quality factors of the raw water storage reservoir to supply the outflow water of the backwash wastewater recovery reservoir to the pore-control fiber filter or to return the same to the raw water storage reservoir, and monitor the coagulant injection amount into the flash mixer, the agitation intensity of the first agitator of the two-stage coagulation reservoir, and the agitation intensity of the second agitator of the backwash wastewater recovery reservoir, the chemical injection amount, and the operation state of the pressurized micro-filter,
• wherein the flash mixer further comprises:
• an on-line measurer configured to measure in real time the raw water quality factors including the Chlorophyll-a, the turbidity level, the pH, the water temperature, the pressure, and the flow amount of the raw water of the raw water storage reservoir;
• a coagulant injection controller configured to estimate the membrane pollution state by using the raw water quality factors measured by the on-line measurer, and control the coagulant injection amount according to a reference value of the main water quality factor affecting the membrane filtration resistance, among the raw water quality factors;
• and
• a coagulant injector configured to inject coagulants into the flash mixer under the control of the coagulant injection controller,
• wherein the flow channel switch unit comprises:
• a first electronic valve installed in the first pipe and configured to be opened/closed under the control of the control panel to supply the backwash wastewater from the backwash wastewater recovery reservoir to the pore-control fiber filter;
• and
• a second electronic valve installed in the second pipe and configured to be opened/closed under the control of the control panel to return the backwash wastewater from the backwash wastewater recovery reservoir to the front end of the flash mixer, and
• wherein the control panel is configured to measure the raw water quality factors by the on-line measurer in real time, and open the first electronic valve to supply the backwash wastewater from the backwash wastewater recovery reservoir to the pore-control fiber filter, if the temperature, the turbidity level, and the alga population number are higher than predetermined values.