DEVICE FOR PURIFYING WASTEWATER AND METHOD THEREOF

Abstract: Disclosed is a device and method for clarifying wastewater, in which atomized steel slag balls are packed in a filtration reactor and suspended solids and organic matter contained in the wastewater are electrically attached to the slag balls and removed by passing the wastewater through the filtration reactor. The clarifier has advantages in that production of sludge is minimized because 95 % or more of suspended solids are removed and the desiccative property of the sludge is excellent, the sludge is easily treated and reused because the sludge is not mixed with other materials, slag balls are reused by removing the sludge using a back washing pump after filtration, the cost of equipment is reduced because equipment is simple, management expenses are reduced because slag balls are reused, and secondary pollution is not produced during use of the use of the clarifier.

Description: DEVICE FOR PURIFYING WASTEWATER AND METHOD THEREOF TECHNICAL FIELD The present invention relates, in general, to a device and method for clarifying wastewater using atomized steel slag balls and, in particular, a device and method for clarifying wastewater using atomized steel slag balls, in which organic matters and suspended solids contained in the wastewater are effectively removed by use of magnetic force and static elasticity of the atomized steel slag ball, thereby clarification expenses are largely reduced, clarification efficiency is greatly improved, and secondary pollution is not produced. PRIOR ART As industry advances, industrial wastes are produced in large quantities which indiscriminately destroy natural ecosystems, and human life has been compromised. In particular, water indispensable to humans is seriously contaminated by wastes such as domestic sewage which come from homes, industrial wastes produced from various factories such as a dye works and tanneries, and wastewater containing pollutants such as agricultural chemicals and excretions produced in agriculture, fisheries, and livestock applications. Recently, water pollution has been recognized as one of main factors which threaten human existence, and so much effort has been made to avoid water pollution. Conventionally, the wastewater is collected in a separate wastewater treatment plant, then clarified. One general treatment for clarifying the wastewater uses chemicals to treat the wastewater. However, chemical treatment has disadvantages in that management expenses of treatment devices are high because chemicals used to treat the wastewater are added to it, secondary pollution is caused by chemicals, and excessive treatment expenses are needed to treat sludge as by- products. Another treatment involves filtration as physical methods whereby the wastewater is passed through gravel, sand, or anthracite to be filtered. But, the filtration is disadvantageous in that clarification efficiency is low due to long clarification time, additional wastes such as sand are produced from treatment procedures because it is impossible for sand used in a filtration basin to be re-treated, management expenses are high because auxiliary plants such as mixing and coagulation basins are needed, and ionized microscopic substances are difficult to remove. DISCLOSURE OF THE INVENTION Therefore, it is an object of the present invention to avoid the above disadvantages, and to provide a device and method for clarifying wastewater using atomized steel slag balls, in which the wastewater is inexpensively clarified with the use of spherical steel slag balls atomized by cooling them under a water spray. It is another object of the present invention to provide a device and method for clarifying wastewater using atomized steel slag balls, in which the wastewater can be sufficiently treated with the use of spherical steel slag balls atomized by cooling them under a water spray, thereby the clarification process becomes simple and so it's expenses are lowered. It is still another object of the present invention to provide a device and method for clarifying wastewater using atomized steel slag balls which have excellent durability, so that the steel slag ball can be reutilized, thereby management expenses for clarification are greatly reduced and secondary pollution is not produced during use of the clarifier. It is yet another object of the present invention to provide a device and method for clarifying wastewater using atomized steel slag balls, in which the wastewater is clarified and the clarified water is reused, thereby water used in industry can be reduced. Based on the present invention, the above objects can be accomplished by a provision of a device and method for clarifying wastewater using atomized steel slag balls, in which when the wastewater is passed through a filter reactor having atomized steel slag balls as filter media packed therein, suspended solids and organic matters contained in the wastewater are electrically attached on steel slag ball's surface and are thus removed from the water. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. 1 schematically illustrates a mechanism of clarifying wastewater in accordance with the present invention; Fig. 2 schematically illustrates a wastewater clarifier using atomized steel slag balls according to an embodiment of the present invention; and Fig. 3 schematically illustrates wastewater clarifiers using atomized steel slag balls which are positioned in a river according to another embodiment of the present invention. BEST MODES FOR CARRYING OUT THE INVENTION According to an embodiment of the present invention, a device A for clarifying wastewater using atomized steel slag balls (Hereinafter, referred to as "slag ball") comprises a filtration reactor 2 in which a slag ball bed containing slag balls 1 is formed, an equalization tank 3 for supplying the wastewater which will be treated into the filtration reactor 2, and a treated water tank 4 for collecting the treated water treated in the filtration reactor 2, as shown in Fig. 2. In addition, a back washing pump 5 for washing slag balls 1 is positioned at a lower portion of the filtration reactor 2, and a delivery valve 21 for delivering back washing water discharged from the filtration reactor 2 to a back washing water storage tank 6 is positioned at a upper portion of the filtration reactor 2. The slag ball 1 is atomized by passing steel slag of 1000 "C or more, melted in an electric furnace through a sprayed water current and rapidly cooling it, resulting in a slag ball which has a crystalline structure which is like glass because a spinel structure has been formed in the steel slag ball. This spinel structure has Vickers hardness of 740 in general, and is produced as a slag which is modified into a mineral with an excellent resistance to weathering and water resistance. Because the spinel structure is produced as the slag during steel manufacture, the spinel structure contains Fe 2 O 3 , and so it is magnetized and it's surface has a plurality of electrostatic charges (negative charge). Components constituting the spinel structure are Ca of 42 to 63 wt %, Fe 2 O 3 of 22 to 35 wt %, SiO 2 of 9 to 11 wt %, MgO of 6 to 9 wt %, FeO of 3 wt %, and remaining Fe, and composition of the spinel structure may be slightly varied. With reference to Fig. 1, there is schematically illustrated a mechanism of clarification for wastewater in accordance with the present invention. When wastewater is fed into the filtration reactor 2 in which slag balls of the present invention are packed, suspended solids or organics in the wastewater contact or come close to the slag balls. Because the slag ball 1 has a negative charge on its surface, the colloid particles adjacent to the slag ball 1 are electrically induced in such a way that a positive charge is generated on the side facing the slag ball 1, with the other side charged negatively. The electrical induction on the colloid particles which are in direct contact with the slag ball 1 also gives electric charges to the colloid particles which come to contact with the electrically induced colloid particles. Thus, such electric induction may ensue to some extent, electrostatistically aggregating contaminants, such as suspended solids, organic matters capable of inducing color in wastewater, cations, etc., onto the slag ball 1. As described above, a clarifier of the present invention, in which atomized steel slag balls are packed into a filter reactor and suspended solids and organic matter contained in the wastewater are electrically attached to steel slag balls to be removed by passing the wastewater through the filter reactor, has advantages in that treatment capacity of the wastewater is greatly increased because time needed to clarify the wastewater according to the present invention is 7 to 8 times shorter than a conventional filtration process using sand as filter media, removal efficiency of organic matter and suspended solids is much higher than that of the conventional process, and the turbidity removal efficiency is an excellent 90 % or more. Other advantages of the clarifier according to the present invention are that production of sludge is minimized because 95 % or more of suspended solids are removed and desiccative property of the sludge is excellent, the sludge can be easily treated and reused because the sludge is not mixed with other materials such as sand, slag balls can be reused by removing the sludge from the slag balls with the use of a back washing pump after filtration, the cost of equipment is greatly reduced because equipment is simple, management expenses are reduced because slag balls are reused, and secondary pollution is not produced during use of the clarifier. Turning now to Fig. 3, barriers B, in which atomized slag balls are packed, and positioned in a river. A water current naturally passes through the barriers B, thereby contaminated water can be inexpensively treated and a conventional method for clarifying the wastewater is greatly improved. A better understanding of the present invention may be obtained by reading the following examples which are set forth to illustrate, but are not to be construed to limit the present invention. EXAMPLE 1 Before being treated, wastewater was measured to be 61.02 in chemical oxygen demand (COD), 22.73 in total organic carbon (TOC), 24.22 in suspended solid (SS), 45.24 in NH 4 -N, 50.22 in total nitrogen (TN), 6.13 in total phosphorus (TP), 495 NTU in turbidity, 60.1 in Ca, 10.2 in Mg, and 0.98 in Fe (unit: mg/L). After the wastewater passed through a filtration reactor 2 for about 10 min, in which slag balls 1 with a diameter of 0.5 to 1.5 mm were packed, the analysis of the wastewater treated that COD was 29.75, TOC was 12.54, SS was 8.8, NFL÷-N was 22.50, TN was 23.32, TP was 0.54, turbidity was 72 NTU, and Ca, Mg, and Fe contained in the wastewater were 79.8, 1.02, and 0.11, respectively. COMPARATIVE EXAMPLE Before being treated, the wastewater was measured to be 57.55 in chemical oxygen demand (COD), 21.80 in total organic carbon (TOC), 22.95 in suspended solid (SS), 40.84 in NH 4 -N, 46.52 in total nitrogen (TN), 6:45 in total phosphorus (TP), 484 NTU in turbidity, 60.0 in Ca, 10.1 in Mg, and 1.12 in Fe (unit: mg/L). After the wastewater passed through the filtration reactor for about 90 min, in which sand with a diameter of 0.45 to 0.7 mm, gravel, and charcoal were packed, the analysis of the wastewater treated that COD was 45.98, TOC was 17.20, SS was 13.0, NH t -N was 32.69, TN was 36.12, TP was 1.93, turbidity was 132 NTU, and Ca, Mg, and Fe contained in the wastewater were 76.2, 8.40, and 0.68, respectively. These results show the present invention's advantages such as treatment capacity of the wastewater being greatly increased because time needed to clarify the wastewater according to the present invention is 7 to 8 times shorter than a conventional filtration process using sand, elimination efficiency of organic matters and suspended solids is much higher than that of the conventional process, and the turbidity removal efficiency is an excellent 90 % or more. Other advantages of the clarifier according to the present invention are that sludge is easily separated from the slag balls because suspended solids are removed by 95 % or more and abscission property of the sludge is excellent, the sludge can be easily treated and reutilized because the sludge is not mixed with other materials such as sand, and slag balls can be reused by removing the sludge from the slag balls with the use of a back washing pump after filtration. INDUSTRIAL APPLICABILITY As described above, the present invention provides a device and method for clarifying wastewater using atomized steel slag balls, which can be applied to factories or the agriculture and livestock where wastewater is discharged, and can inexpensively clarify a river or lake which has been seriously polluted. The present invention has been described in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, it is to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims: CLAIMS 1. A wastewater clarifier, comprising a filtration reactor with atomized slag balls packed as filter media, in which wastewater is filtered while passing through a slag ball bed. 2. The clarifier according to claim 1, wherein the filtration reactor is equipped with: an equalization tank for supplying treated feed wastewater into the filtration reactor; a treated water tank for collecting the water treated in the filtration reactor; a back washing pump, positioned at a lower portion of the filtration reactor, for washing the slag ball bed; and a delivery valve, positioned at an upper portion of the filtration reactor, for delivering back washing water discharged to a back washing water storage tank from the filtration reactor. 3. The clarifier according to claim 1, wherein the filtration reactor, having atomized slag balls packed therein, is positioned in a river so that a water current is filtered while passing through the filtration reactor. 4. A method for clarifying wastewater, in which wastewater is passed through the atomized slag ball bed, thereby removing contaminants contained in the wastewater. 5. The method according to claim 4, wherein the water current is filtered while passing through the atomized slag ball bed positioned in a river.

Inventors: OH SANG YOON, OH, SANG, YOON
Applicants: ECOMAISTER CO LTD, OH SANG YOON, ECOMAISTER CO., LTD, OH, SANG, YOON
Application year: 2001
Main classification: B01D24
IPC codes: B01D24, B01D29, B01D35, B01D39, C02F1