Abstract:
Colored wastewater from industries, agriculture and the like is discolored by adjusting pH of the wastewater and filtering the wastewater through a mixture of acid-treated sawdust produced from sawdust which has been disposed of after being used for fungi production and charcoal thereby to remove a color component fraction from the wastewater and through a filter material, for example acid-treated rice husk charcoal, in which autochthonous microorganisms are embedded thereby to absorb color components remaining in the wastewater.

Description:
REFERENCE TO RELATED APPLICATION 
     The disclosure of Japanese patent application JP 2007-200522, filed Aug. 1, 2007, based upon which Convention priority is claimed, is hereby incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to a colored wastewater discoloration method, which can discolor and make colored wastewater and the like being generated from various production sites, human daily activities and so on and such as dye and pigment wastewater from textile industry and the like, pottery manufacturing industry wastewater containing glaze and the like, plating wastewater from metal-processing industry and the like, livestock industry wastewater, agroforestry wastewater, food industry wastewater, chemical and oil industry wastewater, electrical and electronics industry wastewater, iron and machine industry wastewater, restaurant industry wastewater and the like, into clear and colorless water, as well as reducing BOD, COD, total nitrogen, total phosphorus and so on. 
     Conventional methods to discolor high-concentration or low-concentration colored wastewater, generated from various production activities, vary in treatment techniques according to generation and quality of the wastewater. However, none of such methods uses a single technique. They use a combination of two or three techniques, yet not achieving satisfactory treatment. Especially discoloration has hardly been achieved ever. 
     In case the wastewater volume to be treated is small, such treatment methods are available as disposal treatment by an outsourced industrial waste collector, electrolytic cleaning treatment by electrolysis, agglomeration-separation cleaning treatment using coagulant such as anion and cation, activated sludge treatment by biodegradation treatment, and so on. However, all of these treatment methods are facing ever increasing production costs including for treatment facilities and various running costs, including for treatment of byproducts generated therefrom. 
     Thus, in reality it has been practiced, in case the colored wastewater to be treated is large in volume and contains no harmful substances, that it is mixed with substantial amount of industrial water and/or sea water and so on and then discharged into nature. 
     SUMMARY OF THE INVENTION 
     In view of the conventional drawback as described above, it is an object of the present invention to provide a colored wastewater discoloration method, which can discolor and make colored wastewater, being generated from various production sites and human daily activities, into clear and colorless water, efficiently by a simple method, as well as reducing BOD, COD, total nitrogen, total phosphorus and so on at low cost. 
     The above and further objects and novel features of the present invention will more fully appear from the following detailed description when the same is read in connection with the accompanying drawings. 
     It is to be understood that these are for the purpose of illustration only and are not intended to be definition of the limits of the invention. 
     In order to achieve the above mentioned purpose, the present invention comprises a colored wastewater discoloration method including: an acid adjustment process wherein colored wastewater such as dye and pigment wastewater from textile industry and the like, pottery manufacturing industry wastewater containing glaze and the like, plating wastewater from metal-processing industry and the like, livestock industry wastewater, agroforestry wastewater, food industry wastewater, chemical and oil industry wastewater, electrical and electronics industry wastewater, iron and machine industry wastewater, restaurant industry wastewater and the like, are acid adjusted to pH 4 or lower by mixing with acid adjuster; a color component fraction separation process, wherein the acid wastewater, which has been treated in the acid adjustment process, is mixed as the alkaline adjuster to adjust the pH of the wastewater to at least 10 and this alkaline wastewater is passed through a color component fraction separation filter layer which is a mixture of acid treated sawdust with charcoal such as rice husk charcoal and activated carbon, the acid treated sawdust being made from sawdust which had been used for production of fungi; and then an adsorptive separation process wherein the remaining wastewater is passed through a filter laye, such as rice husk charcoal, embedded with autochthonous-microorganisms, i.e., microorganisms existing in nature, thereby to absorb remaining color components on the filter layer. 
     According to another aspect of the invention, the present invention is comprised of a colored wastewater discoloration method including: a color component fraction separation process wherein the color components fraction of the wastewater is separated in such manner that, in case the colored wastewater is acid wastewater, alkaline adjuster is added to and mixed with it until pH reaches 10 or over, followed by a step wherein acid adjuster is added to and mixed with it until pH reaches 3 or lower, or in case the colored wastewater is alkaline wastewater, acid adjuster is added to and mixed with it until pH reaches 3 or lower, followed by a step wherein alkaline adjuster is added to and mixed with it until pH reaches 10 or over; and an adsorptive separation process wherein following the color component fraction separation process, the remaining wastewater is passed through a filter layer, preferably of acid-treated rice husk charcoal, to adsorb remaining color components thereon, autochthonous-microorganisms, i.e., microorganisms existing in nature, having been embedded in the filter layer. 
     As is clear form the above-mentioned explanations, the present invention as hereinabove defined provides the effects enumerated below. 
     The present invention is, according to certain embodiments thereof, comprised of: an acid adjustment process wherein colored wastewater such as dye and pigment wastewater from textile industry and the like, pottery manufacturing industry wastewater containing glaze and the like, plating wastewater from metal-processing industry and the like, livestock industry wastewater, agroforestry wastewater, food industry wastewater, chemical and oil industry wastewater, electrical and electronics industry wastewater, iron and machine industry wastewater, restaurant industry wastewater and the like, are acid adjusted to pH 4 or lower by mixing with acid adjuster; a color component separation process, wherein, after the acid adjustment process, a color components-containing fraction of the acid wastewater is separated by passing the acid wastewater, which has been treated by the acid adjustment process, through a color component fraction separation filter layer which has been adjusted to be pH10 or over by adding alkaline adjuster to the filter layer, i.e., contacting the filter layer with alkaline adjuster, the filter layer being a mixture of acid treated sawdust made from sawdust disposed of in fungi production with charcoal such as rice husk charcoal and activated carbon; and an adsorptive separation process wherein following the color component fraction separation process, the wastewater from which the color components fraction has been separated is passed through a filter layer to be adsorbed thereon, the filter layer preferably being acid-treated rice husk charcoal, autochthonous-microorganisms, i.e., microorganisms existing in nature, having been embedded in the filter layer. 
     Therefore, the present invention can make the colored wastewater clear and colorless. 
     In the process described above, the filter layer embedded with autochtonous microorganisms can reduce content of BOD, COD, total nitrogen, total phosphorous and so on contained in the colored wastewater. 
     In the process described above, because no special facility is required, treatment of the colored wastewater can be done easily, in a short time, and at low cost. 
     In the process described above, because of passing the colored wastewater through the color component fraction separation filter layer and the autochthonous microorganisms embedded filter layer, treatment of the colored wastewater can be done easily and in a short time. 
     In the process described above, by treatment of the wastewater with the color component fraction separation filter layer and the filter layer embedded with autochthonous microorganisms, traces of precious metals and hazardous substances can be adsorptively separated. 
     According to other embodiments of the invention, wastewater which is initially acidic, instead of alkaline, can be treated equally effectively. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a process diagram to practice a first preferred embodiment of the present invention. 
         FIG. 2  is a schematic diagram to practice the first preferred embodiment to practice the present invention. 
         FIG. 3  is a process diagram to practice a second embodiment of the present invention. 
         FIG. 4  is a schematic diagram to practice the second embodiment of the present invention. 
         FIG. 5  is a process diagram to practice a third embodiment of the present invention. 
         FIG. 6  is a schematic diagram to practice the third embodiment of the present invention. 
         FIG. 7  is a process diagram to practice a fourth embodiment of the present invention. 
         FIG. 8  is a schematic diagram to practice the fourth embodiment of the present invention. 
         FIG. 9  is a process diagram to practice a fifth embodiment of the present invention. 
         FIG. 10  is a schematic diagram to practice the fifth embodiment of the present invention. 
         FIG. 11  is a process diagram to practice a sixth embodiment of the present invention. 
         FIG. 12  is a schematic diagram to practice the sixth embodiment of the present invention. 
         FIG. 13  is a process diagram to practice a seventh embodiment of the present invention. 
         FIG. 14  is a schematic diagram to practice the seventh embodiment of the present invention. 
         FIG. 15  is a process diagram to practice an eighth embodiment of the present invention. 
         FIG. 16  is a schematic diagram to practice the eighth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Preferred embodiments to practice the present invention will now be described in detail below referring to the accompanying drawings. 
     A first preferred embodiment to practice the present invention is shown in  FIGS. 1 and 2 , wherein  1  represents the colored wastewater discoloration method of the present invention, which can discolor and make colored wastewater  2  being generated from various production sites, human daily activities and so on and such as dye and pigment wastewater from textile industry and the like, pottery manufacturing industry wastewater containing glaze and the like, plating wastewater from metal-processing industry and the like, livestock industry wastewater, agroforestry wastewater, food industry wastewater, chemical and oil industry wastewater, electrical and electronics industry wastewater, iron and machine industry wastewater, restaurant industry wastewater and the like, into clear and colorless water  2 A. The colored wastewater discoloration method  1  is comprised of: an acid adjustment process  3  wherein the colored wastewater  2  is acid adjusted; a color component fraction separation process  5  wherein, after the acid adjustment process, a color components fraction of acid wastewater  4  is separated; an adsorptive separation process  7  wherein, after the color component fraction separation process, remaining color components in the wastewater are adsorptively separated in a filter layer  6  embedded with autochthonous microorganisms; and a water discharge process  8  wherein clear and colorless water resulting from the adsorptive separation process  7 , is discharged. 
     As illustrated in  FIG. 2 , in the acid adjustment process  3 , colored wastewater  2  is supplied into a tank  11  through a colored wastewater supply pipe  10  having an intermediate pump  9 , followed by agitation, using an agitator  12 , of the colored wastewater  2  in the tank  11 , while supplying acid adjuster  13  such as hydrochloric acid, nitric acid, sulfuric acid and so on from an acid adjuster supply tank  14 , to adjust the colored wastewater  2  into the acid wastewater  4  of pH is 4 or less, preferably less than 2, to be measured by a pH sensor  15 . 
     In the color component fraction separation process  5 , the acid wastewater  4  is passed through a color component fraction separation filter layer  16 . As illustrated in  FIG. 2 , the color component fraction separation filter layer  16  is comprised of: a color component fraction separation filter cylinder  20  to which the acid wastewater  4  in the tank  11  in the acid adjustment process  3  is supplied through a pump  17  and a supply pipe  18  and from which the wastewater is discharged into a tank  19 ; acid-treated sawdust  21  which is made from sawdust being disposed of in fungi production is contained in a filter layer within the color component fraction separation filter cylinder  20 , the filter layer  25  being a mixture of the acid-treated sawdust  21  with rice husk charcoal and activated carbon  22 ; the wastewater in the cylinder  20  is mixed with alkaline adjuster  23  supplied from an alkaline adjuster supply tank  24  so that the pH within the cylinder  20  becomes 10 or above. 
     As illustrated in  FIG. 2 , the microorganism-embedded filter  6 , used in the adsorptive separation process, is comprised of: an adsorptive filtration cylinder  29  to which the wastewater in the tank  19  from which the color component fraction has been separated is supplied through a pump  26  and a supply pipe  27 , and then discharged from the cylinder  29  into a tank  28 ; and an adsorptive separation filter layer  31  made of rice husk charcoal, which has been acid-treated and then embedded with autochthonous-microorganisms, i.e., microorganisms existing in nature, is contained in the cylinder  29 . 
     In the water discharge process  8 , clear and colorless water  2 A in the tank  28  used in the adsorptive separation process  7  is discharged to outside through a pump  32  and a water drainage hose  33 . 
     Most of the color components of the colored wastewater  2  treated by the colored wastewater discoloration method are separated from the wastewater by passing the wastewater through the filter layer  25  the pH of which has been adjusted to be, like the pH of the color component fraction separation filter layer  16 , 10 or above, whereupon the wastewater looses color and fades. 
     Also, by passing the thus treated wastewater through the adsorptive separation filter layer body  31  in the adsorptive separation process  7 , the colored wastewater, having already lost color and faded, will have more than 99% of its remaining color components adsorbed thereon, and then is discharged as clear, colorless and clean water. 
     A point to be noted is that the tank  28  used in the adsorptive separation process  7  has a pH sensor  34  therein, because of which the water is discharged only when the pH is within the set value of the pH sensor  34 . 
     Explained next are other embodiments to practice the present invention as illustrated in  FIGS. 3 to 16 . In explaining these other embodiments to practice the present invention, the same component parts as those in the first preferred embodiment to practice the present invention, are given the same numerals in order to avoid the overlapping explanations. 
     A second embodiment to practice the present invention is shown in  FIGS. 3 and 4 . It is distinguished from the first preferred embodiment to practice the present invention that a second adsorptive separation process  35  utilizing a microorganisms-embedded filter layer  31  is performed after the adsorptive separation process  7 . A colored wastewater discoloration method  1 A utilizing a second adsorptive separation process  35  as described above provides effects similar to those of the first preferred embodiment to practice the present invention, as well as additional adsorptive separation of color components of the colored wastewater. 
     A third embodiment to practice the present invention is shown in  FIGS. 5 and 6 . It is distinguished from the second embodiment to practice the present invention that: the acid adjuster can be provided to contact microorganisms-embedded filter layers  31 , 31  in the adsorptive separation process  7  and a second adsorptive separation process  35 , the treatment operation automatically stops by receiving signal from pH sensors  34 ,  34  when set value is exceeded, and the acid adjuster  13  is provided from the acid adjuster tank  14  to contact the microorganisms-embedded filter layers  31 , 31  to wash them for function recovery; and the acid adjuster  13  is also supplied through a supply pipe  36  into the tank  11  in which the acid adjustment process  3  is performed. 
     Another possible arrangement is that, simultaneously with automatic shutoff of the treatment operation, the alkaline adjuster  23  is supplied from the alkaline adjuster supply tank  24  to contact the color component fraction separation filter layer  16  in the color component fraction separation process  5  so as to restart operation automatically after alkalinity recovery. 
     A fourth embodiment to practice the present invention is shown in  FIGS. 7 and 8 . It is distinguished from the first preferred embodiment to practice the present invention in that a color component fraction separation process  5 A is performed by utilizing a color component fraction separation filter layer  16 A having filter layers  25 ,  25  installed in such manner as to form a dual layer within the color component fraction separation filter cylinder  20 . A colored wastewater discoloration method  1 B utilizing a color component fraction separation process  5 A as described above provides effects similar to those of the first preferred embodiment to practice the present invention. 
     A fifth embodiment to practice the present invention is shown in  FIGS. 9 and 10 . It is distinguished from the first preferred embodiment to practice the present invention in that an adsorptive separation process  7 A is performed by utilizing a microorganisms-embedded filter  6 A having filter layers  31 ,  31  installed in such manner as to form a dual layer within the color component fraction separation filter cylinder  29 . A colored wastewater discoloration method  1 C utilizing an adsorptive separation process  7 A as described above provides effects similar to those of the first preferred embodiment to practice the present invention. 
     A sixth embodiment to practice the present invention is shown in  FIGS. 11 and 12 . It is distinguished from the first preferred embodiment to practice the present invention in that a color component separation process  5 B is performed by utilizing a dual filter  37  for color component fraction separation and adsorptive separation of color components, having a filter layer  25  for color component fraction separation and an adsorptive separation filter layer  31  installed in such manner as to form a dual layer within the filter cylinder  20 . A colored wastewater discoloration method  1 D utilizing an separation process  5 B as described above provides effects similar to those of the first preferred embodiment to practice the present invention. 
     A seventh embodiment to practice the present invention is shown in  FIGS. 13 and 14 . It is distinguished from the sixth embodiment to practice the present invention in that the colored wastewater discoloration method  1 A is performed wherein: an adsorptive separation process  39  is performed, which adsorptively separates mineral oil and so on, floating on colored wastewater  2   a , in a filter  38  containing a filter layer made from mixture of sawdust, wood chips and charcoal, in order to treat colored wastewater  2   a  containing mineral oil and so on generated from metal parts machining in industries such as automotive, shipbuilding, aircraft building, and machine tools; and a water discharge process  8 A is performed, wherein the colored wastewater  2  resulting from treatment of the colored wasterwater  2   a  in the adsorptive separation process  39 , is fed to the color component fraction separation process  5 , followed by the adsorptive separation process  7  and an acid adjustment process  40  in order to discharge water after being adjusted to optimum pH for discharge into nature. Such a treatment method as described above removes mineral oil, color components and so on from the colored wastewater  2   a  containing mineral oil and so on, so that the colored wastewater is treated to be made into clear and colorless water optimum for discharge into nature. 
     An eighth embodiment to practice the present invention is shown in  FIGS. 15 and 16 . It is distinguished from the first preferred embodiment to practice the present invention that a colored wastewater discoloration method  1 F is performed wherein: a color component fraction separation process  5 C is performed, which separates a color components fraction of the colored wastewater from the colored wastewater in such manner that, in case the colored wastewater is the acid wastewater  4 , the alkaline adjuster  23  is added to and mixed with it until pH reaches 10 or over, followed by a step wherein the acid adjuster  13  is added to and mixed with it until pH reaches 3 or lower, or in case the colored wastewater is the alkaline wastewater  41 , the acid adjuster  13  is added to and mixed with it until pH reaches 3 or lower, followed by a step wherein the alkaline adjuster  23  is added to and mixed with it until pH reaches 10 or over; and the adsorptive separation process  7  is performed following the color component fraction separation process  5 C. In the adsorptive separation process  7 , the wastewater from which the color components fraction has been separated is passed through a filter layer for remaining color components to be adsorbed thereon, the filter layer being a material, such as acid-treated rice husk charcoal, in which are embedded autochthonous-microorganisms, i.e., microorganisms existing in nature. Such a treatment method as described above provides effects-similar to those of the first preferred embodiment to practice the present invention as well as an intensive discoloration of the colored wastewater. 
     The present invention is applicable in the industry of treating colored wastewater generated in various production sites, human daily activities and so on.