Disk filter for preventing scale formation and water treatment apparatus and method using the same

1. A water treatment apparatus comprising:

a disk filter comprising:

a housing;

a raw water inlet formed at a predetermined position on a side surface of the housing;

a raw water outlet formed at a central region in a bottom of the housing;

a backwash water outlet formed at a central region in a top of the housing;

a ceramic filter provided inside the housing, the ceramic filter having an upper barrier and a lower barrier to allow backwash water supplied by a recovery unit to flow through the ceramic filter during a backwash process, wherein the backwash water flows through the recovery unit and is then supplied to flow through the ceramic filter during the backwash process;

a scale formation inhibitor loaded in a flow channel formed inside the ceramic filter, wherein the raw water introduced via the raw water inlet passes through the ceramic filter and then through the flow channel filled with the scale formation inhibitor, and is then discharged via the raw water outlet;

an anaerobic tank including a first inlet for feeding raw water containing nitrate (NO 3 − ) and a second inlet for feeding raw water containing a carbon source;

an anammox reaction tank including a third inlet for feeding raw water containing an ammonium ion (NH 4 + ) and a treatment water outlet and containing an anammox microorganism therein, the anaerobic tank positioned atop the anammox reaction tank and including an outlet opening on a lower surface thereof in flow communication with the anammox reaction tank; and

the disk filter disposed upstream of the third inlet and configured to remove a scale-inducing material from the raw water containing the ammonium ion, wherein a direction of supply of backwash water through the ceramic filter is always in the opposite direction of a direction of the raw water.

2. The water treatment apparatus of claim 1 , further comprising: the outlet opening including an opening/closing part provided between the anaerobic tank and the anammox reaction tank, wherein raw water treated in the anaerobic tank is transferred to the anammox reaction tank through the opening/closing part.

3. The water treatment apparatus of claim 1 , wherein the anaerobic tank includes a stirrer for mixing the raw water introduced therein.

4. The water treatment apparatus of claim 1 , wherein the anammox reaction tank includes a stirrer for mixing the raw water introduced therein.

5. The water treatment apparatus of claim 1 , wherein the ceramic filter is manufactured by mixing a ceramic powder, a binder, and sodium hexaphosphate.

6. The water treatment apparatus of claim 5 , wherein the ceramic filter is manufactured by mixing 100 parts by weight of the ceramic powder, 10 to 50 parts by weight of the binder, and 20 to 40 parts by weight of the sodium hexaphosphate.

7. The water treatment apparatus of claim 5 , wherein the binder is at least one selected from the group consisting of polypropylene, polyurethane, and ultrahigh-molecular-weight polyethylene.

8. The water treatment apparatus of claim 1 , wherein the scale formation inhibitor is a ball formed of sodium polyphosphate ((NaPO3)x, x being a positive number).

9. The water treatment apparatus of claim 1 , further comprising a loss prevention plate provided at the flow channel filled with the scale formation inhibitor and configured to prevent loss of the scale formation inhibitor.

10. The water treatment apparatus of claim 1 , further comprising: a filter module connected to the treatment water outlet of the anammox reaction tank and into which raw water discharged from the anammox reaction tank is fed; and the recovery unit for supplying backwash water to the filter module.

11. The water treatment apparatus of claim 10 , wherein a disk filter included in the filter module has a pore size of 25 to 300 μm.

12. The water treatment apparatus of claim 10 , wherein the anammox reaction tank includes a measurement part for measuring a sludge concentration of the anammox microorganism contained in the raw water.

13. The water treatment apparatus of claim 12 , wherein the filter module includes a plurality of disk filters having different pore sizes, and a controller is provided to select the disk filter of the plurality of disk filters suitable for filtering raw water depending on the concentration measured using the measurement part of the anammox reaction tank.