Abstract:
A water treatment apparatus includes a first fluid channel that can circulate contaminated water in the water body, a first inlet that draws the contaminated water into the first fluid channel, and an outlet that allows the contaminated water to exit the first fluid channel. A second fluid channel installed with a filter therein can filter contaminated water in the water body to produce a filtered water flow. A fluid transport apparatus can draw the contaminated water through the first fluid channel and the second fluid channel. A flow control system allows water to flow in a predetermined angular range while blocking at least a portion of the remaining angular range in at least one of the first inlet and the outlet to achieve mixing coverage with different aspect ratio. The position of the outlet can be adjusted to optimize the flow rate and pattern.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation-in-part (CIP) application of and claims priority to U.S. patent application Ser. No. 12/047,906, entitled “Integrated water treatment apparatus and methods for natural water improvement” filed Mar. 13, 2008 by the same inventors, the disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to the field of treatment of contaminated or polluted natural water. 
         [0003]    In the present specification, the term “natural water” refers to a body of water, typically outdoors, which requires treatment due to contaminations or pollutions by industrial or domestic activities, or natural phenomena. Examples of natural water include rivers, streams, lakes, reservoirs, ponds, canals, sea water in a bay, and so on. The water body may have different widths and depths, and can stay substantially still or flow at different flow rates. 
         [0004]    In much of the industrialized regions of the world, water treatment facilities are enforced to remove pollutants such as organic wastes and toxic chemicals from the industrial and municipal waste water before they can be discharged into natural water body. However, eutrophication of natural water body becomes an increasingly important issue still as the global climate and environment change under its way. More diseases have been identified to be resulted from the eutrophication of natural water and blue green algae bloom. To improve the water quality in the natural water, various natural water management measures such as lake and pond circulator, wetland system, aerators, and etc. have been deployed in natural water bodies. These measures aim to reduce eutrophication through reducing nutrient loads, improving biodiversity and balance thus to suppress bad algae bloom in natural water. 
         [0005]    In some developing regions of the world, due to financial constraints, low economic priority, and inefficiency in law enforcement, natural waters in these regions are sometimes severely polluted by organic wastes and toxic chemicals at levels far exceeding water&#39;s natural capability to clean itself up. The high eutrophication rate of natural waters has raised global concerns. People in these regions more frequently experienced the water resource related environmental crisis, which caused loss of sources of drinking water, shut-down of factories, evacuation of population, and many health problems. Although various measures mentioned above have been implemented but hardly in a large scale, little progress has been demonstrated largely because of the cost, technology, and engineering integration issues. In particular, a technology and apparatus that can effectively reduce Total Nitrogen (TN), Total Phosphorus (TP), Biological Oxygen Demand (BOD), and Chemical Oxygen Demand (COD) in a part or the whole natural water body is highly desired to combat the eutrophication of natural water. 
         [0006]    Another need in natural water treatment is to provide water treatment apparatus that can be efficiently clean water in water bodies of different environment. 
       SUMMARY OF THE INVENTION 
       [0007]    In a general aspect, the present invention relates to a water treatment apparatus that includes a float that can float on the surface of a water body, a first fluid channel coupled to the float and that can circulate contaminated water in the water body, a second fluid channel coupled to the float and that can filter contaminated water in the water body, and a fluid transport apparatus configured to draw the contaminated water through the first fluid channel at a first flow rate and through the second fluid channel at a second flow rate. 
         [0008]    In another general aspect, the present invention relates to a water treatment apparatus that includes a float that can float on the surface of a water body, a first fluid channel coupled to the float and that can circulate contaminated water in the water body, a first air conduit that can transfer air or oxygen to aerate the contaminated water flowing through the first fluid channel, a second fluid channel coupled to the float and that can filter contaminated water in the water body, a second air conduit that can transfer air oxygen to aerate the contaminated water flowing through the second fluid channel; and a fluid transport apparatus configured to draw the contaminated water through the first fluid channel and the second fluid channel. 
         [0009]    In yet another general aspect, the present invention relates to a water treatment apparatus that includes a float configured to float on the surface of a water body, a first fluid channel coupled to the float and configured to circulate contaminated water in the water body. At least a portion of the first fluid channel can be formed by a first flexible tube that allows the first fluid channel to vary in length in accordance to different water levels. The water treatment apparatus also includes a first air conduit configured to transfer air or oxygen to aerate the contaminated water flowing through the first fluid channel, a second fluid channel coupled to the float and comprising a filter configured to filter contaminated water in the water body. At least a portion of the first fluid channel is disposed inside the second fluid channel. At least a portion of the second fluid channel is formed by a second flexible tube that allows the second fluid channel to vary in length in accordance to the different water levels. The water treatment apparatus also includes a second air conduit configured to transfer air oxygen to aerate the contaminated water flowing through the second fluid channel, legs configured to stand on a floor of the water body to support at least a portion of the weight of the first fluid channel and the second fluid channel, and a fluid transport apparatus comprising a motor and an impeller rotatably coupled to the motor and can draw the contaminated water through the first fluid channel at a first flow rate in a range between about 5 and about 500 gallons per minute. The impeller can draw the contaminated water through the second fluid channel at a second flow rate in a range between about 1,000 and about 5,000 gallons per minute. The first fluid channel, the second fluid channel, and the fluid transport apparatus can be disposed under the float when the water treatment apparatus is deployed in a water body. 
         [0010]    Implementations of the system may include one or more of the following. At least a portion of the first fluid channel can be disposed inside the second fluid channel. The first fluid channel and the second fluid channel can have variable lengths to allow the float to adapt to different water levels. At least a portion of the first fluid channel can be formed by a first flexible tube that allows the first fluid channel to vary in length in accordance to the different water levels. At least a portion of the second fluid channel can be formed by a second flexible tube that allows the second fluid channel to vary in length in accordance to the different water levels. The first flexible tube can have a first variable length in a range from about 0.5 meter to about 8 meters, and wherein the second flexible tube has a second variable length in a range from about 1 meter to about 10 meters. The first flow rate can be in a range between about 5 and about 500 gallons per minute. The second flow rate can be in a range between about 1,000 and about 5,000 gallons per minute. The water treatment apparatus can further include a filter installed in the first fluid channel and capable of filtering the contaminated water flowing through the first fluid channel. The filter can include a material selected from the group consisting of active carbon, porous silica, polyethylene media, a biological reaction carrier, or a chemical reaction carrier. The water treatment apparatus can further include a first air conduit that can transfer air or oxygen to aerate the contaminated water flowing through the first fluid channel and a second air conduit that can transfer air or oxygen to aerate the contaminated water flowing through the second fluid channel. Air or oxygen can be transferred to the first fluid channel by the first air conduit at a rate lower than the rate of air or oxygen transferred to the second fluid channel by the second air conduit. Air or oxygen can be transferred to the first fluid channel by the first air conduit at a rate from about 1 to about 5 liters/min. Air or oxygen can be transferred to the second fluid channel by the second air conduit at a rate from about 5 to about 30 liters/min. The fluid transport apparatus can include a motor and an impeller rotatably coupled to the motor, wherein the impeller is configured to draw the contaminated water through the first fluid channel and the second fluid channel. The first fluid channel, the second fluid channel, and the fluid transport apparatus can be disposed under the float when the water treatment apparatus is deployed in a water body. The water treatment apparatus can further include legs configured to stand on a floor of the water body to support at least a portion of the weight of the first fluid channel and the second fluid channel. The water treatment apparatus can further include means for tying the first fluid channel, the second fluid channel, and the fluid transport apparatus to an object at the floor of the water body. The float can have a diameter in a range from about 0.5 meter to about 3 meters. The first fluid channel can have a length in a range from about 1 meter to about 10 meters and a diameter in a range from about 0.5 meter to about 4 meters. The second fluid channel can have a length in a range from about 1 to about 10 meters and a diameter in a range from about 1 meter to about 5 meters. The water treatment apparatus can further include a rim around an outlet of the second fluid channel. Outlets of the first fluid channel and the second fluid channel can be positioned below the float when the water treatment apparatus is deployed in a water body. The contaminated water exiting the first fluid channel and the second fluid channel can flow through a gap between the float and the rim. 
         [0011]    In a general aspect, the present invention relates to a water treatment apparatus that includes a float configured to float on the surface of a water body; a first fluid channel coupled to the float and configured to circulate contaminated water in the water body; a first inlet that can draw the contaminated water into the first fluid channel; an outlet that can allow the contaminated water to exit the first fluid channel; a flow control system that can allow water to flow in a first predetermined angular range while blocking at least a portion of the remaining angular range in at least one of the first inlet and the outlet; a second fluid channel coupled to the float and comprising a filter installed therein, the second fluid channel configured to filter contaminated water in the water body to produce a filtered water flow; and a fluid transport apparatus that can draw the contaminated water through the first fluid channel and the second fluid channel. 
         [0012]    Implementations of the system may include one or more of the following. The flow control system can allow water to flow in the first predetermined angular range while blocking at least a portion of the remaining angular range in both the first inlet and the outlet. The flow control system can allow water to flow in a first predetermined angular range while blocking all remaining angular range in at least one of the first inlet and the outlet, wherein the first predetermined angular range can have an angular range between about 30 degrees and about 330 degrees. The water treatment apparatus can be installed at a distance between about 1 meter and about 5 meters from the bank of a water body with the blocked angular range facing the bank of the water body. The flow control system can allow water to flow in a second predetermined angular range separate and opposing to the first predetermined angular range in at least one of the first inlet and the outlet, while blocking all remaining angular ranges. The first predetermined angular range and the second predetermined angular range each can have an angular range between about 30 degrees and about 150 degrees. The fluid transport apparatus can produce laminar water flows toward the first inlet or from the outlet in the first predetermined angular range and the second predetermined angular range, wherein the laminar water flows define an elongated region with a long dimension along the middle of the first predetermined angular range or the second predetermined angular range, wherein the elongated region has an aspect ratio between about 5 and about 50. The water treatment apparatus can further include a second inlet that can draw the contaminated water in the water body into the second fluid channel, wherein the outlet is configured to allow the filtered water flow to exit the second fluid channel. The flow control system can allow water to flow in the first predetermined angular range through the second inlet while blocking at least a portion of the remaining angular range in the second inlet. The water treatment apparatus can further include a mechanism configured to adjust of the width of the outlet. The fluid transport apparatus can draw the contaminated water through the first fluid channel at a first flow rate and through the second fluid channel at a second flow rate. At least a portion of the first fluid channel can be disposed inside the second fluid channel. The first fluid channel and the second fluid channel can have variable lengths to allow the float to adapt to different water levels. At least a portion of the first fluid channel can be formed by a first flexible tube that allows the first fluid channel to vary in length in accordance to the different water levels, and wherein at least a portion of the second fluid channel is formed by a second flexible tube that allows the second fluid channel to vary in length in accordance to the different water levels. The first flexible tube can have a first variable length in a range from about 0.5 meter to about 8 meters, and wherein the second flexible tube has a second variable length in a range from about 1 meter to about 10 meters. The first fluid channel, the second fluid channel, and the fluid transport apparatus can be disposed under the float when the water treatment apparatus is deployed in a water body. The float can have a diameter in a range from about 0.5 meter to about 3 meters. 
         [0013]    In another general aspect, the present invention relates to a water treatment apparatus that includes a float that can float on the surface of a water body; a first fluid channel coupled to the float and configured to circulate contaminated water in the water body; a first inlet that can draw the contaminated water into the first fluid channel; an outlet that can allow the contaminated water to exit the first fluid channel; a second fluid channel coupled to the float and comprising a filter installed therein, the second fluid channel that can filter contaminated water in the water body to produce a filtered water flow, wherein the first fluid channel and the second fluid channel can have variable lengths to allow the float to adapt to different water levels; a flow control system that can allow water to flow in a first predetermined angular range while blocking at least a portion of the remaining angular range in at least one of the first inlet and the outlet; and a fluid transport apparatus that can draw the contaminated water through the first fluid channel at a first flow rate and the second fluid channel at a second flow rate. 
         [0014]    In yet another general aspect, the present invention relates to a water treatment apparatus that includes a float that can float on the surface of a water body; a first fluid channel coupled to the float and configured to circulate contaminated water in the water body; a first inlet that can draw the contaminated water into the first fluid channel; a second fluid channel coupled to the float and comprising a filter installed therein, the second fluid channel configured to filter contaminated water in the water body to produce a filter water flow, wherein at least a portion of the first fluid channel can be disposed inside the second fluid channel; a second inlet that can draw the contaminated water in the water body into the second fluid channel; an outlet that can allow the contaminated water to exit the first fluid channel and the filter water flow to exit the second fluid channel; a flow control system that can allow water to flow in a first predetermined angular range while blocking at least a portion of the remaining angular range in at least one of the first inlet, the second inlet, and the outlet; and a fluid transport apparatus that can draw the contaminated water through the first fluid channel and the second fluid channel. 
         [0015]    In a general aspect, the present invention relates to a water treatment apparatus that includes a uniquely-designed system of float and water distributing dish or bowl, where partial of the gap or channel is blocked with an insertion or a hump as part of the shape of the float or dish. Such design allows the water to preferentially flow out through an opening in a certain direction(s) and/or pattern(s). In another general aspect, the present invention relates to a water treatment apparatus that includes three adjusting knobs to control the depth of a water distributing dish or bowl under water. In yet another general aspect, the present invention relates to a water treatment apparatus that includes two intakes with controllable openings. The size and angle of the opening by design match the opening in the float-dish distributing system mentioned above. Such design allows the water to flow in through the openings in a certain direction(s) and/or pattern(s). 
         [0016]    Implementations of the system may include one or more of the following. The upper water distributing system at least consists of a float and a distributing dish or bowl. The flow rate and pattern can be controlled by the size and shape of the gap between the float and distributing dish. A float with a hump of certain shape or a dish with a hump of certain shape or an insertion block of a certain shape can be implemented to form a float-dish gap preferentially blocked to completely block or reduce the flow rate in a certain direction. Normally the height of the hump or insertion block is determined by how much water is allowed to pass over. The angular range of the hump or insertion block can be from 30 degree and 270 degree depending the spread or coverage pattern of a water flow. If the angular range is 180 deg, water can spread in half a circle mode. The water area behind the blind (or shutter) or insertion block can be less mixed or mixed at a lower rate. The height of a hump or insertion block also depends on depth of the distributing dish or bowl under the water. The depth of a distributing dish under water is adjustable through adjusting the three position knobs which are spaced by 120 deg. To facilitate the designed flow pattern, the intake flow can be controlled near the bottom of the water. The two intakes can each include 6 blinds spaced by 60 degree. There are two positions for the blinds: open and close. When the blinds are closed the blinds align along the circumvention orientation. When the blinds are open, the blinds are along the radical direction. The close and openness of the blinds can be determined by the design of flow pattern. The close of the blinds should match the angular range of the hump or insertion blocks of the float-dish system. Therefore, the water taken from the bottom of the water travels through hoses and flows out through the opening of the float-dish system. 
         [0017]    Embodiments may include one or more of the following advantages. The disclosed apparatus and methods can provide effective water treatment to a natural water body with a wide range of contamination and pollution. The disclosed apparatus and methods can remove the pollutants (totally suspended solid (TSS), heavy metals, etc), reduce the nutrient level (TN, TP, BOD, COD), improve dissolved oxygen level, enhance the biodiversity and balance, and suppress the growth of harmful microorganisms such as blue green algae in natural water body. 
         [0018]    The present invention provide effective circulation, aeration diffusion, and filtration in an integrated apparatus to allow water treatment to be simultaneously conducted to achieve physical, chemical, and biological treatment goals. Bio-solid reduction, odor reduction, conversion and reduction of ammonia and nitrate, and thus suppression of blue green algae bloom in natural waters such as lakes and ponds, etc. can be accomplished. 
         [0019]    The disclosed water treatment apparatus includes several water treatment capabilities such as circulation, aeration and diffusion, physical, chemical, and biological filtration, and chemical or biological reactions. The disclosed water treatment apparatus can effectively reduce the nutrient level in the water body through reduction of BOD, NH3, TN, TSS, and TP; circulate and aerate the water body to eliminate odors and fish kills; and eliminate bad algae bloom through suppressing the blue green algae growth and enhance the wellness of the food chain. 
         [0020]    Moreover, the disclosed apparatus and methods allow easy and flexible deployment in different natural water environments. The disclosed water treatment apparatus is adjustable to be suitable for shallow or deep natural water bodies. The disclosed water treatment apparatus can remain stable in natural water that is still or flow at different rates like in rivers. The disclosed water treatment apparatus can be powered externally or by naturally generated power such as wind power or solar energy. 
         [0021]    The disclosed water treatment apparatus is effective in bio-solid reduction, odor reduction, conversion and reduction of ammonia and nitrate, and suppression of blue green algae bloom in natural waters such as lakes and ponds etc. 
         [0022]    Furthermore, the disclosed water treatment apparatus is aesthetically appealing with small footprint that minimizes the visual impact to the environment. 
         [0023]    Although the invention has been particularly shown and described with reference to multiple embodiments, it will be understood by persons skilled in the relevant art that various changes in form and details can be made therein without departing from the spirit and scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The following drawings, which are incorporated in and from a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the invention. 
           [0025]      FIG. 1  is a side view of a water treatment apparatus in accordance to the present invention. 
           [0026]      FIG. 2  is a front cross-sectional view of the water treatment apparatus of  FIG. 1 . 
           [0027]      FIG. 3  is a detailed front view of the top portion of the water treatment apparatus of  FIG. 1 . 
           [0028]      FIG. 4  is a detailed top perspective view of the top portion of the water treatment apparatus of  FIG. 1 . 
           [0029]      FIG. 5  is a detailed top perspective view of the top portion of the water treatment apparatus of  FIG. 1  after the cover is removed. 
           [0030]      FIG. 6  is a detailed top perspective view of the top portion of the water treatment apparatus of  FIG. 1  after the cover and the impeller are removed. 
           [0031]      FIG. 7  is a front cross-sectional view of another water treatment apparatus in accordance to the present invention. 
           [0032]      FIGS. 8A and 8B  show the water flow directions respectively at the lower and surface levels for the water treatment apparatus shown in  FIGS. 1 and 7 . 
           [0033]      FIG. 8C  shows the water outflow directions near the surface level of the water treatment apparatus of in  FIGS. 1 and 7  that is installed in a narrow river. 
           [0034]      FIG. 9  is a front cross-sectional view of another water treatment apparatus in accordance to the present invention. 
           [0035]      FIGS. 10A and 10B  show the water flow directions respectively at the lower and surface levels for the water treatment apparatus shown in  FIG. 9 . 
           [0036]      FIG. 10C  shows the water flow directions near the surface level of the water treatment apparatus of in  FIG. 9  that is installed in the middle of a narrow river. 
           [0037]      FIG. 11  is a front cross-sectional view of another water treatment apparatus in accordance to the present invention. 
           [0038]      FIGS. 12A and 12B  show the water flow directions respectively at the lower and surface levels for the water treatment apparatus shown in  FIG. 11 . 
           [0039]      FIG. 12C  shows the water flow directions near the surface level of the water treatment apparatus of in  FIG. 11  that is installed by the bank of a river. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    Referring to  FIGS. 1 and 2 , a water treatment apparatus  10  includes an upper section  100  and a lower section  200 . The lower section  200  includes a base plate  210  and a plurality of legs  220  connected to the base plate  210 . The legs  220  can stand on the water bed of a water body to support the water treatment apparatus  10 . The legs  220  can be screwed on to the base plate  210  with adjustable heights to allow leveling of the base plate  210  according to height variation of the water bed. 
         [0041]    The lower section  200  includes an inlet  230 , a wall  240  and an rigid reactor wall  315  mounted to the base plate  210 , a filter  320  housed in the reactor wall  315 , a flexible inner tube  275  connected to the reactor wall  315 , a connection tube  285  with its lower ring connected to the flexible inner tube  275 , and an outlet  280  connecting the upper ring of the connection tube  285  and the lower ring of the connection tube  285 , where both rings use brackets  140  to fasten the flexible tubes  275  and  270 . The flexible inner tube  275  can be made of PVC or other polymer materials. The inlet  230 , the wall  240 , the reactor wall  315 , the filter  320 , the flexible inner tube  275 , and the connection tube  285  define a reactor channel  340 . Contaminated water can flow into the reactor channel  340  from the inlet  230  and exit through the outlet  400  ( FIGS. 4-6 ). The inlet  230  can provide physical screen to keep out fish, leaves, and other large objects in the natural water from entering the reactor channel  340 . The inlet  230  can be formed by a mesh having a plurality of holes or a perforated plate. The openings of the inlet  230  can be directed to horizontal directions. Holes are not required at the bottom of the inlet  230 . 
         [0042]    The reactor wall  315  defines a reactor cage that can remove organic and inorganic wastes from natural water by physical and biochemical reactions. For example, the filter  320  installed in the reactor cage can comprise active carbon, porous silica, polyethylene media, and/or other bio-chemical carrier in a form of chunks, fibers, or woven cloth. The bio-chemical reaction carrier can be specially designed to remove certain biological or organic molecules from water. The filter  320  can be replaced or cleaned and reused after the use for a period of time. A bio-film can be formed on the surfaces of the filter  320  with the appropriate microorganisms to provide oxidation and nitrification of water flowing through the reactor channel  340 , which can effectively reduce BOD, COD, TSS, TN and TP. The filter  320  can be formed by a single section or multiple sections. The length of the reactor and volume of filter media are subject to change depending on the severity of the water pollution and the volume of the natural water. 
         [0043]    The lower section  200  includes a lower outer tube  250  mounted on the base plate  210 , an inlet  260  mounted above the lower outer tube  250 , and an upper outer tube  270  mounted between the brackets  140  and the inlet  260 . The lower outer tube  250  and upper outer tube  270  can be rigid, semi-flexible, or flexible. The lower outer tube  250  and upper outer tube  270  can be made of PVC or other polymer materials. The circulation channel  350  is defined by the space between the outer tube  270  on the outside, and the connection tube  285 , the flexible inner tube  275 , and the reactor wall  315  inside. The water can flow into the circulation channel  350  through the inlet  260  and exit the circulation channel  350  through the outlet  280 . The inlet  260  can be formed by a mesh or a perforated plate to provide physical screen to keep out fish, leaves, and other large objects in the natural water from entering the circulation channel  350 . Strings  281  are tied between the brackets  140  and the inlet  260 , the position of the inlet  260  determines the depth of the circulated water. 
         [0044]    The lower section  200  also includes an air conduit  330  that has an inlet  332  and an outlet  335  in the base plate  210 . The air conduit  330  can also be positioned, for example, in a spiral fashion, around the inner surface of the lower outer tube  250 . The air conduit  330  can receive air or oxygen from an external tube (not shown) connected to the inlet  332  and provides aeration to the water in the circulation channel  350 . An exemplary air or oxygen flow of 5˜30 liters/min can be delivered for an effective aeration. 
         [0045]    The lower section  200  further includes an air conduit  341  that has an inlet  342  and an outlet  345  in the support plate  240  to provide aeration to the reactor channel  340 . The air conduit  341  is wound (not shown), for example, in a spiral fashion, around the inner surface of the support plate  240 . The air conduit  341  can receive air or oxygen from an external tube (not shown) connected to the inlet  342 , and provides aeration to the water in the reactor channel  340  including the water in the filter  320 . An exemplary air or oxygen flow of 1˜5 liters/min can be delivered to provide oxygen for biochemical reactions to take place. The support plate  240  also has holes to let water from the inlet  230  below to flow through into the reactor channel  340 . The support plate  240  and the base plate  210  are coupled by screws. 
         [0046]    The upper section  100 , referring to  FIGS. 1-6 , includes a cover  110  and a float  120  that are mounted on a frame  130 . The frame  130  is connected to brackets  140  by connectors  150 . The brackets  140  are fastened around the upper outer tube  270  and a rim  380 , which securely holds the upper section  100  to the lower section  200 . The rim defines the outlet  400  for the reactor channel  340 . The float  120  can be circularly shaped around the axis defined by the shaft  365 . The bottom of the float  120  can be streamline shaped to allow smooth water flow out of the reactor channel  340  and the circulation channel  350 . The rim  380  can be circular shaped and shaped like a bowl. The upper surface of the rim  380  and the bottom surface of the float  120  can be almost parallel to each other to allow water exiting the reactor channel  340  and the circulation channel  350  to flow in the controlled direction. The rim  380  can have multiple stages and openings to facilitate different water flows at different stages. 
         [0047]    The upper section  100  also includes a motor  352  and a controller  355  that can send control signals to the motor  352 . The cover  110  can be formed by a metal or plastic material to shelter the motor  352  and the controller  355  from precipitation, rain, snow, and sun light. The motor  352  and the controller  355  are mounted on brackets  390  that are clamped on the frame  130  ( FIG. 5 ). The motor  352  can rotate an impeller  360  through a shaft  365 . To provide stability to the impeller, the end of the shaft  365  is mounted in a hole  415  in a crossbar  410  that is fixed across the rim  380  ( FIG. 6 ). Light bulbs  395  can be installed on the brackets  390 . The motor  352 , the controller  355 , and the light bulbs  395  can be powered externally via a cable (not shown) offshore such as normal power supply or solar and wind power. 
         [0048]    The rotation of the impeller  360  can draw water upward from the circulation channel  350  via the outlet  280 . The configuration of the circulation channel  350  and the impeller  360  are so designed that the flow rate in the circulation channel  350  is in a range between about 1,000 and about 5,000 gallons per minute. The rapid flow coupled with the aeration by the air conduit  330  in the circulation channel  350  can facilitate the effective diffusion to reach certain dissolved oxygen level, such as 2˜10 mg/liter, in the circulation channel  350 . 
         [0049]    The rotation of the impeller  360  can simultaneously draw water from the reactor channel  340  via the outlet  400 . The configurations of the reactor channel  340 , the impeller  360 , and the packing density of filtering media are so designed that the flow rate in the reactor channel  340  is in a range between about 5 and about 500 gallons per minute, which can be optimal for thorough biochemical reactions in the reactor cage and effective filtration by the filter  320  to handle BOD and COD loads. Moreover, the aeration by the air conduit  341  will provide the oxygen needed for the biochemical reaction. The lower surface of the float  120  and the rim  380  are so designed that water can flow along the streamline of the float and between the two surfaces  120  and  380  in a near laminar pattern. The float  120  can also be patterned so that the water can flow preferentially in certain angular directions. 
         [0050]    An important feature of the described water treatment apparatus is that at least portions of the outer tube and the inner tube are flexible. The lengths of the upper outer tube  270  and the flexible inner tube  275  are automatically adjustable according to the depth of the water body to allow the float  120  stay at the water surface. The float  120  rises up on the surface of the water body with the rise of the water level, pulling the brackets  140  upward. The outer tube  270  and the flexible inner tube  275  are stretched longer. When the level of water body drops, the float  120  and the brackets  140  move downward along with the surface of the water body. The outer tube  270  and the flexible inner tube  275  shrink to shorter lengths. The water treatment apparatus  10  is thus adaptable to changes in water depth caused by seasonal changes and weather conditions. 
         [0051]    The self-adjustable outer tube  270  and the flexible inner tube  275  allow all or most of the weight of the lower section  200  to be supported by the legs  220  and less weight to be lifted by the float  120 . This allows smaller float  120  to be implemented in the water treatment apparatus  10 . The lifting by the float  120  at the top and the supports by the legs  220  at the bottom in combination provide increased stability to the water treatment apparatus  10  in natural water. 
         [0052]    Another advantageous feature of the described water treatment apparatus is that most of the components in the upper section  100  and the lower section  200  are positioned underneath the cover  100  and the float  120 . The diameter of the float  120  is larger than the lateral spread of the connectors  150  and the width of the outer channel  350 , thus blocking most of the components from view from above. As described, the float  120  can be implemented by small lateral widths due to the weight support by the legs  220 . These in combination allow the described water treatment apparatus to have smaller foot print and few visible components on the surface of the natural water body. The described water treatment apparatus is thus more aesthetically appealing than many convention water treatment apparatuses that include multiple extended floats. The described water treatment apparatus is therefore ideal for deployment in parks, reservoirs, and rivers. 
         [0053]    The water treatment apparatus  10  can have the following exemplified dimensions: the float  120  can have a diameter in a range from about 0.5 meter to about 3 meters. The upper section  100  can have a height in a range from about 0.5 meter to about 1.5 meter and a diameter in a range from about 0.5 meter to about 3 meters. The lower section  200  can have a height in a range from about 2 meters to about 10 meters and a diameter in a range from about 1 meter to about 5 meters. The reactor channel  340  can have a length in a range from about 1 meter to about 10 meters and a diameter in a range from about 0.5 meter to about 4 meters. The circulation channel  350  can have a length in a range from about 1 to about 10 meters. The flexible inner tube  275  is expandable with a length varying in a range from about 0.5 meter to about 8 meters. The flexible upper outer tube  270  is expandable to have a length in a range from about 1 meter to about 10 meters. The expandable range of the inner tube  275  and the upper outer tube  270  allow the float  120  to adapt to a water level variation in a range of +/−0.5˜1 meter, depending on the depth of the nature water where the apparatus to be installed. 
         [0054]    The water treatment apparatus  10  is suitable for a natural water body that is still or flow at different flow rates. The upper section  100  is pulled downward by weights  300  on the floor of the water body to help the water treatment apparatus  10  to stabilize in a flowing water body and windy weather. The brackets  390  can be tied to the weights  300  or other objects on the water bed by chains  310 . The chains  310  can include elastic portions such as springs to allow the upper section  100  to adjust to the depth of the water, to absorb mechanical disturbances in the natural water, and to balance in the center of the weights  300 . The combination of the float  120 , the legs  220 , and the chains  310  and weights  300  can prevent toppling of the water treatment apparatus  10  even under severe weather and water conditions 
         [0055]    The water treatment apparatus  10  can be assembled at the site of deployment. The connectors  150  can be easily opened to allow the components in the upper section  100  to be lifted and the filters  320  to be replaced through the center of the reactor channel  340 . The legs  220  and the base plate  210  can also be detachable from the water treatment apparatus  10 .  FIG. 7  is a front cross-sectional view of another water treatment apparatus  700  in accordance to the present invention. For simplicity, only the water flow channels are shown; the aeration system, the leg support, and the anchors are not shown. The water treatment apparatus  700  have several design differences from the water treatment apparatus  10 . The narrower and longer outlet  710  is defined by the bottom of the float  120  and a rigid upper tube  720  that is connected to the upper outer tube  270 . The upper portion of the rigid upper tube  720  is in the shape of a distributing dish or bowl. Three knobs  730  spaced by approximately  120  degrees are designed to change the width of the outlet  710  and thus the depth of the rigid upper tube  720  under water. The inlets  260  and  230  can each include 12 blinds  290  and  295  each equally spread by 30 degree. The blinds  290  and  295  can be set (manually or electrically) to open and close positions at the inlets  260  and  230  to control water inflows. (The blinds  290 ,  295  are shown at their respective open positions in  FIGS. 7  and  8 A.) The inflows can be allowed in predetermined angular range(s) and blocked in oter angular range(s). For the outer circulation channel, the water flows into the circulation channel  350  through the inlet  260  and exit the circulation channel  350  through the outlet  280 , and then the outlet  710 . For the reaction circulation channel, the water flows into the inlet  230 , through the filter  320  and the reactor channel  340 , and exit the outlet  710 . Both inner and outer circulations are driven by the impeller  360 . 
         [0056]    The water treatment apparatus  10  and the water treatment apparatus  700  (in the configuration shown in  FIG. 7 ) can be installed in a wide water body such as lakes and ponds.  FIG. 8A  shows directions of water inflows that enter the water treatment apparatus  10 ,  700  at the inlets  230  and  260  at the lower levels when water treatment apparatus  10 ,  700  is installed in the middle of a wide water body.  FIG. 8B  shows directions of water outflows that exit the outlet  710  (or  280 ) of the water treatment apparatus  10 ,  700  at the surface level. The water flows approximately have a circular symmetry when they are not inhibited by water boundaries of solid objects in the water body. 
         [0057]    When the water treatment apparatus  10 ,  700  is installed in a narrower water body, however, the water flows can be interrupted. As shown in  FIG. 8C , a river  800  may have a width of 10 to 50 meters and may be several kilometers long. The water treatment apparatus  10 ,  700  (i.e. the float  120  in  FIGS. 1-3 ,  7 ) can have a diameter in a range from about 0.5 meter to about 3 meters. The effective water flow range of the disclosed water treatment apparatus can be in a range between 100 to 200 meters, which can often be much wider than the width of a river. When the outflows run into the banks  810 ,  820  of the river  800 , the outflows are reflected and pushed back to form backflows, which increases the resistance for the impeller ( 360  in  FIGS. 1-3 ,  7 ) to push out the water and produces significant amount of energy loss. The narrower rivers produce higher resistance, and cause bigger the energy loss. 
         [0058]    In some embodiments, the water treatment apparatus  700  can be arranged in different configurations to overcome the above described drawbacks. As shown in  FIGS. 9-10B , the water treatment apparatus  700  has certain angular sections of the inlets  230 ,  260  and the outlet  710  are blocked by inlet blinds  290  and  295 , and distributor blocks  910  respectively. For example, two opposite (e.g. the left and the right) sides of the circularly shaped inlets  230 ,  260  and the outlet  710  can be blocked while leaving the front and the back of the inlets  230 ,  260  and the outlet  710  open for water circulation. The distributor blocks  910  and the inlet blinds  290 ,  295  can block an angular range having a width of about 30 degrees to about 150 degree, or about 120 degree, on each side of the water treatment apparatus  700 . In other words, the opening for the front or the back the inlets  230 ,  260  and the outlet  710  can have an angular width from about 30 degrees to about 150 degrees. 
         [0059]    The water treatment apparatus  700  can installed in the middle of the narrower river  800  with the unblocked angular segments aligned along the river  800 , as shown in  FIG. 10C . The distributor blocks  910  and the inlet blinds  290  and  295  can completely block or partially suppress the water flows toward and from the river banks  810 ,  820 . The unblocked inlets  230 ,  260  and the outlet  710  allow efficient laminar inflows and outflows for water mixing in the front and the back directions. The water flows are suppressed in regions  1010 ,  1020  outside of the distributor blocks  910  and the inlet blinds  290  and  295 , wherein the water is diffusively mixing. The propelling energy of the water treatment apparatus  700  is concentrated in the unblocked angular directions to allow the inflow and outflows reaching longer distance along the river  800 . The effective laminar flow region can have a width W and a length L. The aspect ratio L/W can be significantly higher than 1 (i.e. the unblocked scenario), for example, in a range between about 5 and about 50, or between about 20 and 40. 
         [0060]    In some embodiments, as shown in  FIGS. 11-12B  the water treatment apparatus  700  can include the inlet blinds  290  and  295  and the distributor block  910  to the inlets  230 ,  260  and the outlet  710  only one side of the apparatus. For example, the left side of the circularly shaped inlets  230 ,  260  and the outlet  710  can be blocked in an angular range having a width of about 30 degrees to about 330 degrees, or 180 degrees. The front, the back, and the right side of the inlets  230 ,  260  and the outlet  710  are left open for water circulation. The opening for the front or the back the inlets  230 ,  260  and the outlet  710  can have an angular width from about 30 to about 330 degrees. 
         [0061]    The water treatment apparatus  700 , shown in  FIGS. 12C , can be installed with chains and anchors near the river bank  820  with the blocked angular segment facing the river bank  820 . The water treatment apparatus  700  can be installed a distance between about 1 meter and about 5 meters from the river bank  820 , depending on the width of the river. The unblocked inlets  230 ,  260  and the outlet  710  allow efficient laminar inflows and outflows for water mixing in the front, the back, and the right side of the water treatment apparatus  700 . The water flows are suppressed in region  1210  outside of the inlet blinds  290 ,  295 , and the distributor block  910 , and between the river bank  820  and the water treatment apparatus  700 . The water can be diffusively mixing in region  1210 . The installation location of the water treatment apparatus  700  allows uninhibited water activities on the right side of the river  800 . For example, a boat  1220  can freely pass through along slightly right side of the river, without affecting the water cleaning operation of the water treatment apparatus  700 . 
         [0062]    It is understood that the disclosed water treatment apparatus can be customized to water body environments other than the examples described above. For example, the disclosed water treatment apparatus can be installed near the corner of a water body with more than a 180 degree wide angular range of blocked while allowing a single angular range for laminar-flow water mixing. The distributor blocks can be implemented in many configurations while still compatible with the present invention. For example, the distributor blocks can partially block water flow in certain angular ranges to allow a reduced laminar water flow and water mixing in the corresponding angular directions. The aspect ratio of the laminar mixing region can be customized. 
         [0063]    The disclosed apparatus and methods can include one or more of the following advantages. The disclosed water treatment apparatus is significantly more efficient than previous designed systems. The water circulation coverage is much increased in the certain direction. Energy losses related to back flows are much reduced. The suppression of water flow toward river banks can also reduce erosion in the river banks, which makes the disclosed apparatus more environmental friendly. 
         [0064]    The disclosed apparatus and methods can provide effective water treatment to a natural water body with a wide range of contamination and pollution. The disclosed apparatus and methods can remove the pollutants (TSS, heavy metals, etc), reduce the nutrient level (TN, TP, BOD, COD), improve dissolved oxygen level, enhance the biodiversity and balance, and suppress the growth of harmful microorganisms such as blue green algae in natural water body. 
         [0065]    The disclosed apparatus and methods can provide effective circulation, aeration diffusion, and filtration in an integrated apparatus to allow water treatment to be simultaneously conducted to achieve physical, chemical, and biological treatment goals. Bio-solid reduction, odor reduction, conversion and reduction of ammonia and nitrate, and thus suppression of blue green algae bloom in natural waters such as lakes and ponds, etc. can be accomplished. 
         [0066]    The disclosed water treatment apparatus includes several water treatment capabilities such as circulation, aeration and diffusion, physical, chemical, and biological filtration, and chemical or biological reactions. The disclosed water treatment apparatus can effectively reduce the nutrient level in the water body through reduction of BOD, NH3, TN, TSS, and TP; to circulate and aerate the water body to eliminate odors and fish kills; and to eliminate bad algae bloom through suppressing the blue green algae growth and enhance the wellness of the food chain 
         [0067]    Moreover, the disclosed apparatus and methods allow easy and flexible deployment in different natural water environments. The disclosed water treatment apparatus is adjustable to be suitable for shallow or deep natural water bodies. The disclosed water treatment apparatus can remain stable in natural water that is still or flow at different rates like in rivers. The disclosed water treatment apparatus can be powered externally or by naturally generated power like wind power or solar energy. 
         [0068]    The disclosed water treatment apparatus is effective in bio-solid reduction, odor reduction, conversion and reduction of ammonia and nitrate, and suppression of blue green algae bloom in natural waters such as lakes and ponds, etc. 
         [0069]    Furthermore, the disclosed water treatment apparatus is aesthetically appealing with small footprint that minimizes the visual impact to the environment. 
         [0070]    It is understood that the disclosed water treatment apparatus is applicable to a wide range of environment such as fresh water lagoons, lakes, reservoirs, rivers, waste water treatment plants, and waste water ponds. The relative positions of the reactor channel and the circulation channel can vary. For example, the reactor channel can be inner channel and the circulation channel can be outer channel, and vice versa.