Abstract:
The present invention relates to a granular carrier and a method for producing the same, and to an apparatus for treating sewage or waste water by using the granular carriers. The granular carrier comprises a tire powder of 100 parts by weight, an EVA or its derivative of 30 to 50 parts by weight, and an activated carbon or inorganic micropowder equivalent thereto of 5 to 15 parts by weight. The granular carriers producing method comprises the steps of: mixing a tire powder of 100 parts by weight and an EVA or resin of 30 to 50 parts by weight, resolving the EVA or its derivative of the mixture at a temperature of 100 to 250° C., bonding an activated carbon to the tire powder, extruding the mixture, cutting the mixture extruded, and attaching the activated carbon powder to the EVA or its derivative dissolved on the surface of the cut part of the mixture. The sewage or waste water treatment apparatus is also disclosed.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a granular carriers and a method for producing the same, and to an apparatus for treating sewage or waste water by using the granular carriers. 
     Description of the Prior Art 
     Generally, as a microorganism fixing carrier for treating organisms, a granular carrier with a small specific surface or a coated granular carrier has been utilized in practice. The granular carrier and inorganic powder are required to have a great intensity and a great attaching intensity, respectively. 
     However, in the prior art, since the specific surface of the granular carrier is small, the number of the microorganisms attached thereto is reduced. In case that the granular carrier has a large specific surface, during a prolonged aeration, the attached inorganic powder is separated from the carrier. Particularly, in case of treating certain industrial waste water, the carrier is worn out due to the hot waste water and mechanical shocks so that the specific surface of the carrier is not sufficiently utilized, the control of the size thereof within a desired range is difficult and the techniques for controlling the temperature and moisture in a reaction chamber is required. 
     Furthermore, as a method for treating indissoluble waste water of high density, an activated sludge treatment method has been widely used. The activated sludge treatment method resolves polluters dissolved in the waste water by using only sludge microorganisms in an aeration tank. However, since a quantity of mixed liquid suspended solids (“MLSS”) in the aeration tank is about 2,000 to 3,000 mg/L, the treatment time is increased, thereby an amount of air to be consumed becomes larger, resulting in a larger air generating arrangement for injecting air artificially. In order to get a large amount of air with a low cost, the activated sludge treatment method employs a root blower instead of a compressor which results in a high cost. Pressure of the root blower is limited to a range of 0.5 to 0.6 Kg/Cm 2 , thereby the height of a water tank is restricted to a range of about 4 to 6 meters. Under the above condition, since only 3 to 7% of oxygen supplied is dissolved in the water, a large amount of air must be required. 
     As described above, in the prior art, it is difficult to control within a desired range the grain size of the carriers for treating sewage or waste water and to produce the carriers. In addition, the sewage or waste water treatment apparatus requires a large amount of air, thereby resulting in a high cost. 
     SUMMARY OF THE INVENTION 
     It is, therefore, a primary object of the invention to provide a granular carrier having a great mechanical wear-resistance, a great chemical-resistance, a high intensity, a high inorganic powder attachment intensity, and an increased specific surface, thereby allowing a great number of microorganisms to attach to the surface thereof, resulting in a high speed treatment of sewage or waste water. 
     It is another object of the invention to provide a method in which a ratio of components to be mixed and the size and specific gravity of granular carrier can be adjusted with ease so that the requirements for various uses can be achieved with ease and yield is considerably increased. 
     It is still another object of the invention to provide an apparatus for treating sewage or waste water by, using the above granular carriers, the apparatus treating the sewage or waste water rapidly by the granular carriers being once projected and circulated in a treatment tank without any change thereof, thereby increasing the treatment efficiency thereof. 
     In accordance with an aspect of the present invention, there is provided a granular carrier for treating sewage or waste water, comprising: a tire powder of 100 parts by weight; an ethylene vinylacetate copolymer(“EVA”) or its derivative of 30 to 50 parts by weight, the EVA or its derivative which serves as a bonding agent having hydrophilicity and bonding force chemically stable, the EVA or its derivative being insoluble at a high temperature; and an activated carbon or inorganic micropowder equivalent thereto of 5 to 10 parts by weight. 
     In accordance with another aspect of the present invention, there is provided a method of producing granular carriers for treating sewage or waste water, which comprises the steps of: mixing a tire powder of 100 parts by weight and an EVA or resin of 30 to 50 parts by weight, the resin having bonding force and hydrophilicity equivalent to that of the EVA; resolving the EVA or its derivative of the mixture at a temperature of 100 to 250° C.; bonding an activated carbon to the tire powder; extruding the mixture through an extrusion machine; cutting the mixture extruded from the extrusion machine; and attaching the activated carbon powder to the EVA or its derivative dissolved on the surface of the cut part of the mixture. 
     In accordance with still another aspect of the present invention, there is provided an apparatus for treating sewage or waste water by using a plurality of granular carriers, which comprises: an outer housing; an inner case disposed in the outer housing; a supplier for supplying the sewage or waste water, the supplier being installed on top of the outer cylinder; a granular carrier separating duct for removing bubbles attached to the granular carriers therefrom and guiding the granular carriers downwardly, the granular carrier separating duct being located on top of the inner cylinder; an outlet duct for discharging the treated sewage or waste water, the outlet duct being disposed on top of the granular carrier separating duct; an inner and an outer air injection pipes for injecting air into the inner case and the outer housing, respectively, the inner and an outer air injection pipes being spaced apart form each other vertically; a compressed air injection duct for injecting the compressed air into the outer housing, the compressed air injection duct being located under the inner case; an overflow duct for overflowing the sewage or waste water, the overflow duct being disposed over the granular carrier separating duct; a guiding duct for guiding the sewage or waste water overflowed to the outlet duct; and a slant member for guiding the flow direction of sewage or waste water and granular carriers. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects and features of the instant invention will become apparent from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 represents a cross-sectional side elevational view of a sewage or waste water treating apparatus of the present invention; 
     FIG. 2 depicts a cross-sectional side elevational view of the apparatus in FIG. 1, showing the granular carriers and the bubbles which are floating in the apparatus; and 
     FIGS. 3A and 3B set forth transverse-sectional top views of the apparatus in FIG. 1, showing the inner and the outer air injection pipes, respectively. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Experiment 1 
     Tire powder of 100 parts by weight with a particle size of 0.2 to 3 mm, EVA or its derivative of 30, 40 or 50 parts by weight, and activated carbon micropowder of 10 parts by weight with a grain size of 200 mesh are mixed by using a mixer. The mixture is heated to a temperature of about 170° C. to completely resolve the EVA or its derivative, and is, then, put into an extrusion machine. 
     The mixture extruding through an exit of the extrusion machine was cut into a number of granular carriers with a uniform size, and activated carbon powder is attached to the EVA or its derivative dissolved on the surface of the cut granular carrier due to the remaining heat thereof, thereby granular carriers with a large specific surface are produced. 
     Average size of the granular carriers produced according to the above was 2 to 11 mm and yield was more than 97%. Furthermore, as a result of digesting or dipping the granular carriers, 70% of the carriers was digested after 7 hours and all of the carriers after 20 hours. The results were as follows: 
     
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 1. 
               
             
             
               
                   
               
               
                 &lt;Experiment 1&gt; 
               
               
                 specific gravity depending on a ratio of components 
               
             
          
           
               
                   
                 Example 1 
                 Example 2 
                 Example 3 
               
               
                   
                   
               
             
          
           
               
                   
                 tire powder 
                 100 
                 100 
                 100 
               
               
                   
                 (part by weight) 
               
               
                   
                 EVA 
                 30 
                 40 
                 50 
               
               
                   
                 (part by weight) 
               
               
                   
                 activated carbon 
                 10 
                 10 
                 10 
               
               
                   
                 (part by weight) 
               
               
                   
                 actual specific 
                 1.13 
                 1.09 
                 1.06 
               
               
                   
                 gravity 
               
               
                   
                 sedimentation velocity 
                 6.5 
                 6.6 
                 6.6 
               
               
                   
                 (Cm/sec) 
               
               
                   
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 1. 
               
             
             
               
                   
               
               
                 &lt;Experiment 1&gt; 
               
               
                 specific gravity depending on a ratio of components 
               
             
          
           
               
                   
                 Example 1 
                 Example 2 
                 Example 3 
               
               
                   
                   
               
             
          
           
               
                   
                 tire powder 
                 100 
                 100 
                 100 
               
               
                   
                 (part by weight) 
               
               
                   
                 EVA 
                 30 
                 40 
                 50 
               
               
                   
                 (part by weight) 
               
               
                   
                 activated carbon 
                 10 
                 10 
                 10 
               
               
                   
                 (part by weight) 
               
               
                   
                 actual specific 
                 1.13 
                 1.09 
                 1.06 
               
               
                   
                 gravity 
               
               
                   
                 sedimentation velocity 
                 6.5 
                 6.6 
                 6.6 
               
               
                   
                 (Cm/sec) 
               
               
                   
                   
               
             
          
         
       
     
     EXAMPLE 2 
     Tire powder of 100 parts by weight with a particle size of 0.2 to 3 mm, EVA or its derivative of 30, 40 or 50 parts by weight are mixed by using a mixer, and then, the mixture is heated to a temperature of about 170° C. to completely resolve the EVA or its derivative and is put into an extrusion machine. The extrusion machine had an exit with a diameter of 8 mm and the extrusion temperature was maintained at 120° C. At that time, the mixture was extruded linear shape and thus extruded linear mixture, then, passes through a water tank in which activated carbon powder of 200 mesh was dissolved so that the activated carbon was attached to the EVA or its derivative dissolved on the surface of the mixture due to the remaining heat thereof. Then, the mixture was quickly cooled by passing through another water tank in which cold water was stored, thereby the activated carbon is attached to the surface of the mixture. The cooled and coated linear mixture was guided into a cutter, being cut into a number of granular carriers with a uniform size. Average size of the granular carriers produced was 9.8 mm and yield was more than 99%. Furthermore, as a result of digesting the granular carriers, 70% of the carriers was digested after 7 hours and all of the carriers after 20 hours. 
     An apparatus for treating sewage or waste water by using the above granular carriers produced according to the present invention will now be described with reference to FIGS. 1 to  3 . 
     The apparatus of the present invention, as shown in FIG. 1, comprises an outer cylinder  10 , an inner cylinder  20  disposed in the outer cylinder  10 , a supplier  30  for supplying the sewage or waste water, the supplier  30  being installed on top of the outer cylinder  10 , a funnel-shaped duct  40  for removing bubbles attached to the granular carriers therefrom and guiding the granular carriers downwardly, the funnel-shaped duct  40  being located on top of the inner cylinder  20 , an outlet duct  50  for discharging the treated sewage or waste water, the outlet duct  50  being disposed on top of the funnel-shaped duct  40 , an inner and an outer air injection pipes  60  and  70  which are spaced apart form each other vertically, a compressed air injection duct  80 , the compressed air injection duct  80  being located under the inner cylinder  20 , an overflow duct  90  for overflowing the sewage or waste water, the overflow duct  90  being disposed over the funnel-shaped duct  40 , a guiding duct  100  for guiding the sewage or waste water overflowed to the outlet duct  50 , and a slant member  110  for guiding the flow of sewage or waste water and granular to the outer cylinder  10 . 
     The outer cylinder  10  has a height of 10 to 15 meters, thereby increasing the treatment efficiency. The outer cylinder  10  is provided with an annular protuberance  11  formed, at a certain position, on the inner surface thereof. The annular protuberance  11  prevents the sewage or waste water and the granular carriers from lifting, thereby allowing them to circulate. 
     The inner cylinder  20  is located in the outer cylinder  10  to define a space  21  therebetween, wherein the sewage or waste water, together with the air injected from the inner and the outer air injection pipes  60  and  70 , flows downwardly. 
     The supplier  30  is disposed on top of the outer cylinder  10 , and an inlet conduit  31  with a certain length extends from the supplier  30  to the inside of the inner cylinder  20 , passing through the funnel-shaped duct  40 . The sewage or waste water is supplied through the inlet conduit  31 . 
     The funnel-shaped duct  40  has a converging portion  41  and the overflow duct  90  has an aperture  91  through which the treated sewage or waste water is overflowed into the guide duct  100 . The outlet conduit  50  is connected to and is in communication with the guide duct  100 . 
     Referring to FIGS. 3A and 3B, the inner and the outer air injection pipes  60  and  70 , respectively, have an inner and an outer annular portion  61  and  71  each of which is provided with a plurality of air vents  62  and  72  through which air is injected. The inner air injection pipe  60  passes through the outer cylinder  10  and the inner cylinder  20 , and the annular portion  61  is positioned in the inner cylinder  20 . The outer air injection pipe  70  passes through the outer cylinder  10 , and the annular portion  71  is positioned around the inner cylinder  20 . It does not matter whether the air vents  62  and  72  are formed such that the air is injected upwardly or downwardly. 
     Referring back to FIGS. 1 and 2, the compressed air injection duct  80  is disposed under the inner cylinder  20 . The compressed air injection duct  80  injects upwardly the compressed air which intermittently flows therein from a compressor (not shown), thereby lifting the depositing polluters and granular carriers. 
     Furthermore, the slant member  110  is located inside of the compressed air injection duct  80 , guiding the flow of sludge and granular carriers. The slant member  110  has a cone-shaped portion, thereby uniformly supplying the fluid into the space  21 . 
     Pebble layer  120  is formed around the compressed air injection duct  80 , prevents various polluters from entering the duct  80 , breaks the bubbles generated in pieces, thereby facilitating the floating of polluters and granular carriers. 
     Operation of the apparatus of the present invention will now be described. 
     Sewage or waste water supplied through the supplier  30  flows downwardly through the inlet conduit  31  and the inner cylinder  20  and, then, flows upwardly through the space  21  between the inner cylinder  20  and the outer cylinder  10 . At this time, the air injected through the air vents  62  of the inner air injection pipe  60  floats sludge. In addition, the air injected through the air vents  72  of the outer air injection pipe  70  floats the sewage or waste water in the space  21 . On the other hand, since the sectional area of the space  21  is larger than that of the inner cylinder  20 , the sewage or waste water in the inner cylinder  20  flows about 4 or 5 times as fast as that in the space  21  and flows, therefore, faster than the floating air therein. Therefore, the air injected through the inner air injection pipe  60  once flows downwardly and then lifts along the space  21 , thereby facilitating the circulation of sewage or waste water. 
     The volume of the descending air becomes less and less due to the water pressure and that of the ascending air becomes greater and greater, thereby increasing the role of air-lift. Since water pressure at bottom is about 1 to 1.5 Kg/Cm 2 , the air transmitting effect is relatively increased. The granular carriers C of the present invention described hereinbefore are previously put into the space  21 , floating in the sewage or waste water, thereby the microorganisms attached to the granular carriers C treat the polluters in the sewage or waste water. That is to say, the granular carriers C floating in the sewage or waste water treat and purify the sewage or waste water, while circulating along with the sewage or waste water. 
     During the above process, bubbles B generated due to the air injected into the space  21 , are combined together while lifting, and burst at the surface of the water. On the other hand, some of the bubbles B are attached to the granular carriers C, thereby lifting the granular carriers C. Since the upper portion area of the space  21  becomes less due to the converging portion of the funnel-shaped duct  40 , collisions among the granular carriers C is increased so that the bubbles B attached thereto are separated from the granular carriers C, thereby resulting in vibrations. Therefore, the floating fine bubbles burst due to the above vibrations. 
     The granular carriers C from which the bubbles B are removed descend along the inner surface of the converging portion  41  of the funnel-shaped duct  40 , being sucked into the inside of the inner cylinder  20 . 
     While resolving various sewage or waste water, microorganisms attached to the granular carriers C get grow. The floating granular carriers C collide with one another, are partly cut out, and, then, descend along the converging portion  41  of the funnel-shaped duct  40 , thereby the size thereof is kept constant. Since being light, the dissolved sludge is discharged together with the treated water, in turn, through the overflow duct  90 , the guide duct  100  and the outlet conduit  50 . After the discharged sewage or waste water is stored in a settling tank (not shown) during a certain period of time, the dissolved sludge is settled, thereby resulting in purified water. 
     On the other hand, the compressed air injection duct  80  injects compressed air intermittently, to thereby lift the depositing sludge and granular carriers. The pebble layer  120  with a height of about 10 to 20 cm is provided around the compressed air injection duct  80 , thereby making easy the lifting of polluters and granular carriers C. In addition, since the injected compressed air strikes the pebbles  120 , the ratio of dissolved oxygen is increased. Furthermore, the polluters and the granular carriers C do not deposit on the bottom of the outer cylinder  10 , thereby preventing the air vents of the compressed air injection duct  80  from being choked. 
     The test results of the apparatus of the present invention were as the following tables 3 and 4. 
     
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 3. 
               
             
             
               
                   
               
               
                 Treatment of living waste water 
               
             
          
           
               
                   
                 activated 
                 apparatus 
                 apparatus 
               
               
                   
                 sludge 
                 with 10 m of 
                 with 15 m of 
               
               
                   
                 treatment 
                 effective 
                 effective 
               
               
                   
                 method 
                 water depth 
                 water depth 
               
               
                   
                   
               
             
          
           
               
                 waste water 
                 120000 
                 120000 
                 120000 
               
               
                 amount (m 3 /day) 
               
               
                 treatment time 
                 6 
                 1 
                 1 
               
               
                 (hour) 
               
               
                 capacity of 
                 30000 
                 5000 
                 5000 
               
               
                 aeration tank 
               
               
                 (m 3 ) 
               
               
                 sludge 
                 2000-3000 
                 15000-20000 
                 15000-20000 
               
               
                 microorganism 
               
               
                 amount (mg/L) 
               
               
                 space load of 
                 0.8 
                 4.8 
                 4.8 
               
               
                 BOD 
               
               
                 (BOD Kg/m 3 /day) 
               
               
                 F/M ratio 
                 0.27-0.40 
                 0.24-0.32 
                 0.24-0.32 
               
               
                 BOD of waste 
                 150-250 
                 150-250 
                 150-250 
               
               
                 water (mg/L) 
               
               
                 BOD of treated 
                 10-25 
                 10-20 
                 10-20 
               
               
                 water (mg/L) 
               
               
                 treatment rate 
                 87-92 
                 88-95 
                 88-95 
               
               
                 (%) 
               
               
                 oxygen 
                 7537.5 
                 7537.5 
                 7537.5 
               
               
                 consumption 
               
               
                 amount 
               
               
                 (KgO 2 /day) 
               
               
                 required air 
                 777463 
                 388732 
                 340134 
               
               
                 amount (Nm 3 /day) 
               
               
                 required air 
                 540 
                 270 
                 237 
               
               
                 amount (Nm 3 /min) 
               
               
                 site area 
                 7500 
                 500 
                 334 
               
               
                 required for 
               
               
                 installation 
               
               
                 (m 2 ) 
               
               
                   
               
               
                 *F/M ratio means that the ratio of food (contaminant) to microorganism  
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 4. 
               
             
             
               
                   
               
               
                 Treatment of indissoluble waste water of papermaking 
               
             
          
           
               
                   
                 activated 
                 apparatus 
                 apparatus 
               
               
                   
                 sludge 
                 with 10 m of 
                 with 15 m of 
               
               
                   
                 treatment 
                 effective 
                 effective 
               
               
                   
                 method 
                 water depth 
                 water depth 
               
               
                   
                   
               
             
          
           
               
                 waste water 
                 10000 
                 10000 
                 10000 
               
               
                 amount (m 3 /day) 
               
               
                 treatment time 
                 24 
                 4 
                 4 
               
               
                 (hour) 
               
               
                 capacity of 
                 10000 
                 1667 
                 1667 
               
               
                 aeration tank 
               
               
                 (m 3 ) 
               
               
                 sludge 
                 2000-3000 
                 15000-20000 
                 15000-20000 
               
               
                 microorganism 
               
               
                 amount (mg/L) 
               
               
                 space load of 
                 0.4 
                 2.4 
                 2.4 
               
               
                 COD 
               
               
                 (COD Kg/m 3 /day) 
               
               
                 F/M ratio 
                 0.13-0.20 
                 0.12-0.16 
                 0.12-0.16 
               
               
                 COD of waste 
                 350-450 
                 350-450 
                 350-450 
               
               
                 water (mg/L) 
               
               
                 COD of treated 
                 30-50 
                 25-45 
                 25-45 
               
               
                 water (mg/L) 
               
               
                 treatment rate 
                 86-93 
                 90-94 
                 90-94 
               
               
                 (%) 
               
               
                 oxygen 
                 2475 
                 2475 
                 2475 
               
               
                 consumption 
               
               
                 amount 
               
               
                 (KgO 2 /day) 
               
               
                 required air 
                 255287 
                 127644 
                 111688 
               
               
                 amount (Nm 3 /day) 
               
               
                 required air 
                 178 
                 89 
                 78 
               
               
                 amount (Nm 3 /min) 
               
               
                 site area 
                 2500 
                 168 
                 112 
               
               
                 required for 
               
               
                 installation 
               
               
                 (m 2 ) 
               
               
                   
               
               
                 *F/M ratio means that the ratio of food (contaminant) to microorganism  
               
             
          
         
       
     
     As seen from the table 3, in case of treating living waste water in which biochemical oxygen demand(“BOD”+ was 150 to 250 mg/L (average: 200 mg/L) and the generating amount thereof was 120000 m 3 /day, the waste water was treated for 6 hours by using the standard activated sludge treatment method and the treatment rate was about 90%. The capacity of aeration tank was 30000 m 3 . Therefore, the space loads of BOD was 0.8 Kg/m 3 /day and F/M ratio was 0.27 to 0.40. In order to install such aeration tank, a site with an area of 7500 m 2  was required. However, in case of using the apparatus of the present invention with an effective depth of water of 10 meters, although F/M ratio was 0.24 to 0.32 as similar as that of the activated sludge treatment method, the volume of aeration tank was reduced to 5000 m 3 , a sixth of that in the activated sludge treatment method, and the space loads of BOD was 4.8 Kg/m 3 /day, 6 times of that in the activated sludge treatment method. Therefore, the site area required to install the aeration tank was 500 m 2 , a fifteenth of that in the activated sludge treatment method. 
     In case of using the apparatus of the present invention with an effective depth of water of 15 meters, the site area required to install the aeration tank was reduced to 334 m 2 , while the other items are similar to those in the apparatus with 10 meters of effective water depth. Although the oxygen consumption amount was 7537.5 KgO 2 /day in all of the above cases, the amount of air required was significantly different. That is to say, in the apparatus with 10 meters of effective water depth, the amount of air required was 270 Nm 3 /min, a half of that in the activated sludge treatment method. In addition, in the apparatus with 15 meters of effective water depth, the amount of air required was 237 NM 3 /min, 43.9% of that in the activated sludge treatment method. 
     On the other hand, as seen in the table 4, in case of treating indissoluble waste water of papermaking in which chemical oxygen demand(“COD”) was 350 to 450 mg/L (average: 400 mg/L) and the producing amount thereof was 10000 m 3 /day, the waste water was treated for 24 to 30 hours by using the standard activated sludge treatment method and the treatment rate was about 90%. The capacity of aeration tank was 10000 m 3 . Therefore, the space loads of COD was 0.4 Kg/m 3 /day and the F/M ratio was 0.13 to 0.20. In order to install such aeration tank, a site with an area of 2500 m 2  was required. 
     However, in case of using the apparatus of the present invention with an effective depth of water of 10 meters, although the F/M ratio was 0.12 to 0.16 as similar as that of the activated sludge treatment method, the volume of aeration tank was reduced to 1667 m 3 , a sixth of that in the activated sludge treatment method, and the space loads of COD was 2.4 Kg/m 3 /day, 6 times of that in the activated sludge treatment method. Therefore, the site area required to install the aeration tank was 168 m 2 , a fifteenth of that in the activated sludge treatment method. 
     In case of using the apparatus of the present invention with an effective depth of water of 15 meters, the site area required to install the aeration tank was reduced to 112 m 2 , while the other indexes are similar to those in the apparatus with 10 meters of effective water depth. Although the oxygen consumption amount was 2475 KgO 2 /day in all of the above cases, the amount of air required was significantly different. That is to say, in the standard activated sludge treatment method, the amount of air required was 178 Nm 3 , in the apparatus with 10 meters of effective water depth, the amount of air required was 89 Nm 3 , a half of that in the activated sludge treatment method. In addition, in the apparatus with 15 meters of effective water depth, the amount of air required was 78 Nm 3 , 43.9% of that in the activated sludge treatment method. 
     As described above, the granular carrier of the present invention has a great mechanical wear-resistance and a great chemical-resistance. Therefore, the intensity of the granular carrier and the attachment intensity of the inorganic powder are increased so that, in an organism treatment apparatus, during an aeration, the attached inorganic powder is prevented from being removed. In case of treating certain industrial waste water, the carrier is not readily worn, even being subjected to the hot waste water and mechanical shocks, thereby sufficiently utilizing the specific surface of the carrier. Particularly, since a great number of microorganisms can be fixed to the surface of carrier by increasing the specific surface of carrier, it is possible to treat sewage or waste water in a shortened period of time. Furthermore, in the production of the carrier of the present invention, since a ratio of components to be mixed and the size and specific gravity of granular carrier can be adjusted with ease, the adjustment required for various uses becomes easier and yield is considerably increased. 
     In addition, according to the sewage or waste water treatment apparatus, the treatment is performed rapidly so that the treatment efficiency is increased. 
     Although the invention has been shown and described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.