CLIAMS:- ,TagSPECI:TECHNICAL FIELD
The present disclosure relates to a method for separation of solid particles from a fluid body. Particularly, the disclosure relates to method of employing chemical coagulation and flocculation for separating solid particles from a fluid body. The present disclosure relates to employing a combination of chemicals in the form of coagulant(s) and flocculant(s) for said separation of solid particles, including but not limiting to living organisms. In an alternative embodiment, the present disclosure also provides further optimization of said separation by employing electro-coagulation and/or pH modulation to said methods of chemical coagulation and flocculation.

BACKGROUND OF THE DISCLOSURE
Conventionally, various methods have been employed to separate solid particles from a fluid body, which included sedimentation, filtration, centrifugation etc. However, said methods have their own limitations when it comes to handling large volumes while separating the solid particles from a fluid body. Further, coagulants and flocculants have been traditionally used in sedimentation, filtration through granular and fluidized (blanket) media, centrifugation, vacuum and pressure filtration, dissolved air flotation and other phase separation processes to enhance the separation. In this regard, coagulants such as aluminum and iron salts as well as their combinations are most widely used. However, there have been common disadvantages of these coagulants while it is being employed with conventional methods such as sedimentation, filtration, centrifugation etc. The conventional coagulants are characterized by high level of swelling and retention of large volume of fluid and they are not entirely stable and tend to produce hydroxide precipitate which considerably reduces the coagulating properties.

Furthermore, to increase phase separation process efficiency during the process of separation, some flocculants such as activated silicic acid have been added to the coagulants. However, addition of such flocculants to the fluid body comprising solid particles requires slow agitation because the formed large flocks often break into smaller flocks by strong agitation. Further, it has been observed that large amount of flocculants and coagulants are required for effective floc-formation. However, since liquid solution of the polymer flocculant has high viscosity, it is difficult to uniformly diffuse the flocculant into the fluid body by slow agitation. In case of employing slow agitation for the purpose of preventing the flocks from being broken into small flocks, it takes a long time to diffuse the polymer flocculant and it causes irregularity in adhesion of the polymer flocculant on the surface of the solid particles and thus sufficient flocculation function cannot be obtained. As a result, an increase in the amount of the polymer flocculant or coagulant added is required.

However, such high dosages of coagulant and flocculant present two fold problems: i) rise in the cost of chemicals, and ii) high chemical content in downstream processing, which would in turn increase the cost of further separation. Nonetheless, the use of fluid bodies including water sources is unavoidable for certain applications such as commercial cultivation of solid particles including but not limiting to living organisms. Use of marine water is considered to be a long term source and sustainable option for said application, since fresh water is fast becoming scarce. However, the current product lines for most coagulant-flocculant manufacturers have been custom designed for fresh water application and not for marine water application thereby restricting the use of coagulant and flocculant in separation of solid particles from a fresh water body and not from marine water. Hence, there has been a long felt need to overcome the limitation observed in the separation of solid particles from a fluid body, particularly from water sources.

Separation of solid particles including but not limiting to living organisms from their environments such as fluid bodies has been a challenge for a long time. Living organisms that are usually found in fluid bodies include Phototrophs or Photoautotrophs, which are autotrophic organisms that carry out photon capture to acquire energy. They use energy from light to carry out various cellular metabolic processes. Phototrophs have many industrial applications such as medium of growth for microorganisms, energy source, fertilizer, bioremediation etc. Thus, separation and harvesting of such organisms from their environment is of industrial and commercial importance. A non-limiting example of such organism is algae, a very large and diverse group of simple organisms, ranging from unicellular to multicellular forms.

Currently, the most economically viable method of cultivating such organisms employs the use of open raceways. However, the areal productivity as well as the concentration of such microorganisms in such raceways is extremely low. Harvesting or separation of such organisms from their growth medium per se is technically possible using physical separation methods such as centrifugation and filtration in a single step. However, a very large volume of dilute micro suspension will have to be handled to separate very small amounts of solid organisms. This makes application of physical separation technologies for harvesting of organisms such as algae economically non-viable and extremely challenging. As a result, presently about 30% of the total production cost is attributed to separation or harvesting. The challenge in such separation/harvesting is thus to develop a method that can significantly reduce the fluid volume to be handled or increase the solid concentration resulting in a slurry that can then be handled viably at the secondary harvesting step (polishing). As an answer to the above said limitations in the separation of solid particles including but not limiting to living organisms, the Applicants of the instant invention intend to arrive at a distinct method for employing separation of solid particles from a fluid body.

STATEMENT OF THE DISCLOSURE
The present disclosure relates to a method for separation of solid particles from a fluid body, wherein the said method employs a unique combination of chemicals for said separation of solid particles.

The present disclosure further relates to a method for employing the combination of chemicals, including but not limiting to coagulant(s) and flocculant(s) for application in separation of solid particles.

In an exemplary embodiment, the disclosure relates to a method for separating solid particles from a fluid body, wherein suitable examples of the solid particles are living organisms including but not limiting to autotrophs such as phototrophs. In another embodiment, said living organisms are either microorganisms or macroorganisms, and the fluid body consists of any one or more of any such organisms.

In an alternative embodiment of the present disclosure, the method of separating solid particles including but not limiting to living organisms, is further optimized by modulating pH while employing the combination of chemicals in the form of coagulant(s) and flocculant(s).
In another alternative embodiment of the present disclosure, the method of separating solid particles including but not limiting to living organisms, is further optimized by providing electric impetus while employing the combination of chemicals in the form of coagulant(s) and flocculant(s).

In yet another alternative embodiment of the present disclosure, the method of separating solid particles including but not limiting to living organisms, is further optimized by combining methods of modulating pH and providing electric impetus while employing the combination of chemicals including but not limiting to coagulant(s) and flocculant(s), wherein the process of pH modulation, electric impetus and combination of said chemicals in the instant method are employed in either a predetermined sequence or in any order thereof within the scope of this disclosure.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
In order that the disclosure may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figures. The figures together with a description below are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present disclosure where:

FIGURE 1 illustrates the action of coagulant(s) and flocculant(s) combination on a fluid body comprising solid particles, wherein A) represents fluid body comprising said solid particles; B) represents pin flock formation after addition of coagulant(s); C) represents aggregation of pin flocks to form larger flocks after addition of flocculant(s); and D) represents settled flock of solid particles after stirring is stopped.

FIGURE 2 illustrates a prospective pattern of coagulant and flocculant requirement for separation of solid particles in pH modulated chemical coagulation-flocculation approach, chemical coagulation-flocculation approach and pH induced flocculation.

FIGURE 3 illustrates a prospective cost analysis pattern of chemicals dosed during separation of solid particles in pH modulated coagulation-flocculation approach, coagulation-flocculation approach and pH induced flocculation.

FIGURE 4 illustrates the total dosage of coagulant and flocculant that may be employed in purely chemical approach and hybrid Electro-coagulation-Chemical-Coagulation-Flocculation approach.

FIGURE 5 illustrates the possible cost involved upon employing coagulant-flocculant approach and hybrid electro-coagulation approach.

FIGURE 6 illustrates the degree of settling of solid particles achieved upon employing hybrid electro-coagulation approach.
FIGURE 7 illustrates the in-situ configuration for hybrid electro-coagulation and coagulation-flocculation approach.

FIGURE 8 illustrates the continuous harvesting configuration for hybrid electro-coagulation and coagulation-flocculation approach.

DETAILED DESCRIPTION OF THE DISCLOSURE
To overcome the non-limited drawbacks of the prior art and to provide for simple, cost-effective and efficient method for separation of solid particles from the environment, preferably fluid body, the present disclosure provides a method of separating solid particles by employing a unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s).

In a non-limiting embodiment, the unique combination of coagulant(s) and flocculant(s) of the present disclosure are employed in a method for separating solid particles from a fluid body including but not limiting to fresh water and marine water or a combination thereof.

In an exemplary embodiment, the unique combination of coagulant(s) and flocculant(s) of the instant method are employed in a method for separating solid particles from a fluid body, wherein suitable examples of the solid particles are living organisms including but not limiting to autotrophs such as phototrophs. In another embodiment, said living organisms are either microorganisms or macroorganisms, and the fluid body consists of any one or more of any such organisms.

In a preferred embodiment, the unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s) of the instant disclosure are employed in a method for separating microorganisms from a fluid body, wherein the fluid body is including but not limiting to fresh water and marine water.

In an exemplary embodiment, the unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s) of the instant disclosure are employed in a method for separating microorganisms including but not limiting to algae, protists, phytoplankton and cyanobacteria from a fluid body, wherein the fluid body is including but not limiting to fresh water and marine water.

In yet another exemplary embodiment, the unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s) of the instant disclosure are employed in a method for separating solid particles having negative charge on their surface, wherein suitable examples of the solid particles are living organisms, including autotrophs such as phototrophs; and wherein such organisms are either microscopic or macroscopic in nature.

In an embodiment, the present disclosure relates to a method of separating solid particles which provides for coagulation and flocculation upon employing the unique combination of chemicals but not limiting to coagulant(s) and flocculant(s).

In another embodiment, the chemical coagulation and flocculation of the instant disclosure is a cost effective and efficient method for separating solid particles from a fluid body, wherein suitable examples of the solid particles are living organisms including autotrophs such as phototrophs. In another embodiment, said living organisms are either microorganisms or macroorganisms, and the fluid body consists of any one or more of any such organisms.

In an embodiment, the natural environment including but not limiting to fresh water and marine water, from which said organisms are separated or harvested, comprise a high salinity in the range of about 3.5% to about 14%, preferably about 7%.

In a non-limiting embodiment of the present disclosure, the unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s) employed in the instant disclosure facilitates agglomeration of solid particles, wherein suitable examples of the solid particles are living organisms, including autotrophs such as phototrophs; and wherein such organisms are either microscopic or macroscopic in nature. In another embodiment, the terms coagulant(s) and flocculant(s) employed in the instant invention must be understood to mean a combination of singular coagulant or multiple coagulants and singular flocculant or multiple flocculants, unless otherwise explicitly recited.

In an exemplary embodiment, the unique combination of coagulant(s) and flocculant(s) employed in the instant disclosure comprises plurality of coagulant and flocculant in any amount or ratio or concentration within the scope of this disclosure.

In an exemplary embodiment of the present disclosure, the coagulant includes but is not limited to a cationic polymer, preferably strongly cationic medium molecular weight organic polymer, strongly cationic low molecular weight organic polymer, a polymer blend comprising inorganic and/or organic polymers or a combination thereof. In an embodiment, the strongly cationic coagulant within the present disclosure represents a coagulant having high charge density, and may have medium or low molecular weight.

In a preferred embodiment, the coagulant belongs to a general class of compounds including but not limiting to polyamines, derivatives of polyamines, aluminum chlorohydrate-polyamines, aluminum-chlorohydrate-polyaluminium, chloride-polyacrylamide-polyamines, blend of polyamines and poly aluminum chloride, or any combination thereof.

In an exemplary embodiment of the present disclosure, the flocculant includes but is not limited to an anionic polymer, preferably strongly anionic high molecular weight polymer. In an embodiment, the strongly anionic flocculant within the present disclosure represents a flocculant having high charge density, and having high molecular weight.

In a preferred embodiment, the flocculant belongs to a general class of compounds including but not limiting to polyacrylamide, copolymer of polyacrylamide, copolymer of acrylamide and sodium acrylate, acrylamide with cationic acrylic acid derivative, polyaluminum chloride and Poly Diallyl-dimethylammonium Chloride, or any combination thereof.

In a non-limiting embodiment of the present disclosure, in the unique combination of coagulant(s) and flocculant(s) employed in the instant disclosure for separating solid particles including microorganisms such as algae, the flocculant may be at a concentration ranging from about 0.01% (w/v) to about 0.5% (w/v) and coagulant may be at a concentration ranging from about 0.01% (w/v) to about 10% (w/v).

In an exemplary embodiment, the percentage recovery of solid particles, including but not limiting to living organisms from a fluid body upon employing the methods of the present disclosure is at least 95% with respect to the unique combination of coagulant and flocculant employed in the methods of the instant disclosure.

In an exemplary embodiment, the present disclosure relates to a method of separating solid particles, wherein suitable examples of solid particles are living organisms, including but not limiting to autotrophs such as phototrophs; and wherein such organisms are either microscopic or macroscopic in nature from a non-limiting fresh water or marine water by employing unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s) of present disclosure through a process of coagulation and flocculation, wherein the said combination in the said method comprises a single dosage or multiple dosage of any one or both of coagulant(s) and flocculant(s).

In a non-limiting embodiment, the present disclosure provides for combining chemicals including but not limiting to coagulant(s) and flocculants(s) in any sequence and for any time period thereof within the scope of this disclosure. Said process of combining of chemicals including but not limiting to coagulant(s) and flocculants(s) provide separation of solid particles, wherein the solid particles are living organisms including but not limiting to autotrophs such as phototrophs; and wherein such organisms are either microorganisms or macroorganisms, from fluid body including but not limiting to fresh water and marine water, through process of coagulation and flocculation, also known as “chemical coagulation and chemical flocculation” or “chemical coagulation-flocculation”.

In a non-limiting embodiment, the present disclosure provides for a method of combining chemicals including but not limiting to coagulant(s) and flocculant(s) for separation of solid particles, including but not limiting to living organisms, from a fluid body including but not limiting to fresh water and marine water, for a process of coagulation and flocculation, wherein said method comprises non-limiting acts of-
a. contacting at least one coagulant(s) with the fluid body in one or more dosages, and mixing the fluid body, followed by contacting at least one flocculant(s) with said fluid body in one or more dosages and subjecting to further mixing for a predetermined time period;
b. reducing or stopping the mixing and allowing the fluid body to settle post the mixing or optionally subjecting the fluid body to a process including but not limiting to air flotation and/or filtration for efficient separation of the solid particles.

In a non-limiting embodiment, the present disclosure provides for a method of combining chemicals including but not limiting to coagulant(s) and flocculant(s) for separation of solid particles, including but not limiting to living organisms, from a fluid body including but not limiting to fresh water and marine water, for a process of coagulation and flocculation, wherein said method comprises non-limiting acts of-
a. contacting first coagulant(s) with the fluid body in one or more dosages and mixing the fluid body, followed by subjecting the fluid body to contacting with second coagulant(s);
b. further mixing the fluid body for a predetermined time period and subjecting said fluid body to contacting with flocculant(s) and mixing;
c. reducing or stopping the mixing and allowing the fluid body to settle post the mixing or optionally subjecting the fluid body to a process including but not limiting to air flotation and/or filtration for efficient separation of the solid particles.

In a non-limiting embodiment, the above described methods of the present disclosure include mixing of fluid body with chemicals including but not limiting to coagulant(s) and flocculant(s), wherein single or multiple dosage of chemicals are added. Such mixing is carried out by any known or conventional technique that a person of average skill in the art deems fit. The said mixing is carried out for predetermined duration and at predetermined speed. For organisms including living organisms such as algae, preferably, the duration ranges from about 10 seconds to about 10 minutes, and the speed of said mixing ranges from about 40rpm to about 400rpm.
In another non-limiting embodiment, duration and speed of mixing in the above described methods may be determined by and/or depended on presence or absence of optional process which include but are not limited to air flotation and/or filtration, wherein these process(s) are optionally employed in the instant method for efficient separation of said solid particles, including but not limiting to living organisms.

In an exemplary embodiment, Figure 1 illustrates the action of coagulant(s) and flocculant(s) combination of the present invention on solid particle settling characteristics, wherein A) represents fluid body comprising said solid particles; B) represents pin flock formation after addition of coagulant(s); C) represents aggregation of pin flocks to form larger flocks after addition of flocculant(s); and D) represents settled flock of solid particles after stirring is stopped.

The unique combination of coagulant(s) and flocculant(s) in the methods of the present disclosure destabilizes the stable solid particles including but not limiting to living organisms, and leads to a formation of large flocks resulting in rapid separation of said solid particles from a fluid body including but not limiting to fresh water or marine water.

In a non-limiting embodiment, the coagulant(s) employed in the methods of the present disclosure destabilizes the solid particles resulting in the formation of pin flocks, which facilitates the formation of large flocks.

In a non-limiting embodiment, the strongly cationic medium or low molecular weight, short chain coagulant(s) employed in the methods of the present disclosure neutralizes the negative surface charge of the solid particles, preferably living organisms, by imparting a slight positive surface charge to said solid particles. Neutralization of the surface charge drastically reduces the mutual repulsion between the solid particles, causing destabilization which results in the formation of pin flock or coagula. Addition of strongly anionic high molecular weight, long chain flocculant(s) to the destabilized solid particles, attracts the slight positive charge of the destabilized solid particles resulting in the formation of large flock, which ranges in the size of few millimeters to centimeters. The effectiveness of flocculant(s) in the above described method is thus dependent on the formation of pin flocks, which is in turn dependent on the efficiency of the coagulant(s). The flocculant(s) will have absolutely no effect if added to a fluid body for separation of such solid particles, including but not limiting to living organisms before addition of sufficient amount of coagulant(s), as the coagulant(s) breaks the stability of the said solid particles,.

In a non-limiting embodiment of any of the above described methods, varied concentration of chemicals including but not limiting to coagulant(s) and flocculant(s) are required for separation of solid particles, wherein suitable examples of the solid particles are living organisms including but not limiting to autotrophs such as phototrophs, which are either microscopic or macroscopic in nature, from a fluid body including but not limiting to fresh water body or marine water. The concentration of said coagulation is dependent on the density of said solid particles, wherein relationship between the coagulant(s) and density of the solid particles is logarithmic, and wherein higher the density, the easier and lower is the total dosage of chemicals per unit biomass.

In an exemplary embodiment, parameters that affect coagulant dosage in any of the above described non-limiting methods include but are not limited to pH, salinity, extracellular organic matter, natural organic matter, particle size, particle concentration and particle type or a combination thereof.

In an exemplary embodiment, effectiveness of any of the above described methods is determined by parameters including but not limiting to coagulant and flocculant dosage, sequence of addition of coagulant and flocculant, period of incubation/mixing and mixing speed, or a combination thereof.

In an exemplary embodiment, the flocks are recovered either by allowing it to settle under gravity in a settling tank or floating it out by attaching micro-bubbles to their surface using a dissolved air flotation. Further, one skilled in the art would be aware that the formed flocks can be recovered by employing various conventional physical and chemical processes without compromising on the yield of the recovery.

In an alternative embodiment of the present disclosure, the above described methods of separating solid particles by employing the unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s) of present disclosure through a process of coagulation and flocculation is further optimized by combining above said coagulation and flocculation with methods including but not limiting to electro-coagulation and pH modulation or a combination thereof.

In an alternative embodiment of the present disclosure, electro-coagulation is combined with the above described methods of coagulation and flocculation, wherein the electro-coagulation involves supply of power or electrical current, preferably with aid of electrodes into the fluid body comprising solid particles, including but not limiting to living organisms, followed by employing the unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s) of the present disclosure. The said combination of electro-coagulation with the chemical coagulation and flocculation of the present disclosure is referred to herein as ‘hybrid electro-coagulation’.

In a preferred embodiment, the electrical current in the hybrid electro-coagulation approach destabilizes the solid particles including but not limiting to living organisms, which is to be separated from a fluid body including but not limiting to fresh water and marine water, and is further augmented by the unique combination of coagulant(s) and floccuant(s) of the present disclosure. The electro-coagulation is an electrochemical method which involves responses of the said solid particles on the fluid body to electric fields and electrically induced oxidation and reduction reaction where sacrificial anodes corrode to release into solution, active coagulant precursors including but not limiting to aluminium, iron and copper, depending on the type of electrode used. At the cathode, gas evolves (usually as hydrogen bubbles) accompanying electrolytic reactions. This therefore causes destabilization of the said solid particles and aggregation of smaller particles into larger particles. Figure 6 illustrates the degree of settling achieved upon employing hybrid electro-coagulation approach while separating solid particles from a fluid body.

In an exemplary embodiment, the hybrid electro-coagulation results in significant reduction of coagulant dosage when compared to the process of chemically separating the solid particles by only using the unique combination of coagulant(s) and flocculant(s). Figure 4 provides prospective consumption of coagulant and flocculant in hybrid electro-coagulation in comparison to pure chemical approach of coagulation-flocculation, for separation of solid particles, including but not limiting to living organisms. The prospective illustration is with respect to, different possible types of solid particles. For example, the solid particles may be of three different types, i.e., type-I, type-II and type-III. The type-I solid particles may have low negative charge with medium surface area per volume ratio; type-II solid particles may have high negative charge with high surface area per volume ratio; and type-III solid particles may have medium negative charge with low surface area per volume ratio. As can be seen from these illustrations, the chemical dosage required in hybrid electro-coagulation has significantly reduced when compared to the chemical separation of solid particles. The illustrations also suggest that the trend may almost be similar for different types of particles. Although, the relative difference in the performance of hybrid electro-coagulation approach in comparison to chemical coagulation-flocculation approach would remain similar for different particle types, the absolute dosages or current to be passed would differ based on the property of the cultivation medium.

In an exemplary embodiment, the hybrid electro-coagulation is cheaper than the conventional chemical approach of separating solid particles. The hybrid electro-coagulation also plays a vital role in reducing the cost involved in separating the solid particles, including but not limiting to living organisms from a fluid body. Figure 5 illustrates the prospective analysis of cost for separating solid particles from a fluid body including but not limiting to fresh water and marine water, upon employing hybrid electro-coagulation and chemical approach of coagulation-flocculation. The said illustration is with respect to different possible types of solid particles. For example, the solid particles may be of three different types, i.e., type-I, type-II and type-III. The type-I solid particles may have low negative charge with medium surface area per volume ratio; type-II solid particles may have high negative charge with high surface area per volume ratio; and type-III solid particles may have medium negative charge with low surface area per volume ratio. As can be seen from these illustrations, the cost for employing hybrid electro-coagulation has significantly reduced when compared to the chemical separation of solid particles. The illustrations also suggest that the trend may almost be similar regardless of different types of particles.

In another embodiment, the hybrid electro-coagulation has a positive impact on the fluid recyclability of the spent medium due to the reduction in the addition of chemicals in to the fluid body during separation of solid particles, including but not limiting to living organisms.

In another embodiment, the hybrid electro-coagulation is simple, efficient, fast, easily deployable and clean and most importantly results in a high degree of settling of the solid particles and thereby enhancing the recovery of solid particles, including but not limiting to living organisms.

In an exemplary embodiment, the present disclosure relates to a method of separating solid particles, including but not limiting to living organisms from a non-limiting fresh or marine fluid body by employing electro-coagulation followed by unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s) of present disclosure through a process of coagulation and flocculation, wherein the said combination in the said method comprises single dosage or multiple dosage of either any or both of coagulant(s) and flocculant(s).

In a non-limiting embodiment, the instant method provides employing current and combining the chemicals including but not limiting to coagulant(s) and flocculants(s) in any sequence and for any time period thereof within the scope of this disclosure. Said process of combining of chemicals including but not limiting to coagulant(s) and flocculants(s) and electric current provides separation of said solid particles from fluid body including but not limiting to fresh water and marine water, through a process of chemical coagulation and chemical flocculation and electro-coagulation and involves plurality of coagulant(s) and/or flocculants(s).

In a non-limiting embodiment, the present disclosure provides for a method of electro-coagulation followed by coagulation and flocculation for separation of solid particles including but not limiting to living organisms, from a fluid body including but not limiting to fresh water and marine water, wherein said method comprises non-limiting acts of-
a. contacting electric current with the fluid body
b. contacting at least one coagulant(s) with the fluid body of step (a) in one or more dosages, and mixing the fluid body, followed by contacting at least one flocculant(s) with said fluid body and subjecting to further mixing;
c. reducing or stopping the mixing and allowing the fluid body to settle post the mixing or optionally subjecting the fluid body to a process including but not limiting to air flotation and/or filtration for efficient separation of the solid particles.

In a non-limiting embodiment, the present disclosure provides for a method of electro-coagulation followed by coagulation and flocculation for separation of solid particles including but not limiting to living organisms, from a fluid body including but not limiting to fresh water and marine water, wherein said method comprises non-limiting acts of-
a. contacting electric current with the fluid body;
b. contacting first coagulant(s) with the fluid body of step (a) in one or more dosages, and mixing the fluid body followed by subjecting the mixed fluid body to contacting with second coagulant(s);
c. further mixing the fluid body and subjecting said fluid body to contacting with flocculant(s) and mixing;
d. reducing or stopping the mixing and allowing the fluid body to settle post the mixing or optionally subjecting the fluid body to a process including but not limiting to air flotation and/or filtration for efficient separation of the solid particles.

In a non-limiting embodiment, the above described methods of the present disclosure include mixing of fluid body with chemicals including but not limiting to coagulant(s) and flocculant(s), wherein single or multiple dosage of chemicals are added. Such mixing is carried out by any known or conventional technique that a person of average skill in the art deems fit. The said mixing is carried out for predetermined duration and at predetermined speed. For organisms including living organisms such as algae, preferably, the duration ranges from about 10 seconds to about 10 minutes, and the speed of said mixing ranges from about 40rpm to about 400rpm.

In another non-limiting embodiment, duration and speed of mixing in the above described methods may be determined by and/or may be dependent on presence or absence of optional process which include but are not limited to air flotation and/or filtration, wherein these process(s) are optionally employed in the instant method for efficient separation of said solid particles including but not limiting to living organisms.

In another non-limiting embodiment, the instant disclosure provides a set-up for performing said hybrid electro-coagulation, wherein the said set-up is in configurations including but not limiting to in-situ configuration and continuous harvesting configuration.

In a preferred embodiment, Figure 7 illustrates the in-situ configuration, wherein the in-situ configuration comprises components including but not limiting to (1) set (s) of electrodes of suitable MOC for affecting electro-coagulation, (2) retractable hydraulic or mechanical arms to mount the electrodes, to immerse and remove the electrodes from the vessel and (3) a DC/AC power supply for providing the necessary power source to affect electro-coagulation. The setup also includes a coagulant and flocculant dosing tank, pumps and the requisite accessories for the same (4). In this configuration the electrode plates are mounted on retractable hydraulic arms which retract during normal cultivation of solid particles, and can be deployed in to the fluid body when separating is to be conducted, wherein the said in-situ configuration is suitable for both small scale and large scale separation of solid particles.

In another preferred embodiment, Figure 8 illustrates the continuous harvesting configuration, wherein said non-in-situ configuration comprises components including but not limiting to (1) set(s) of electrodes of suitable MOC for affecting Electro-coagulation, (2) retractable hydraulic or mechanical arms to mount the electrodes, to immerse and remove the electrodes from the vessel and (3) a DC/AC power supply for providing necessary power source to affect electro-coagulation. The setup also includes a coagulant and flocculant dosing tank, pumps and the requisite accessories for the same (4), set of pumps / pumping station to pump all the fluid to the electro-coagulation unit (5) and a segmented settling tank (6) which is suitable for continuous operation and for large quantity of culture condition.

In another alternative embodiment of the present disclosure, the above described method comprising coagulation-flocculation is combined with a non-limiting strategy of pH modulation, wherein pH of the fluid body comprising solid particles including but not limiting to living organisms; is varied upon addition of a base including but not limiting to sodium hydroxide (NaOH) followed by addition of the unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s) of the instant disclosure. The said method of coagulation-flocculation combined with pH modulation is referred herein as ‘pH modulated coagulation-flocculation’.

In an exemplary embodiment, the method comprising the step of pH modulated coagulation-flocculation reduces the chemical dosage of coagulant(s) and flocculant(s) by about 2 to about 3 folds when compared to a method employing only unique combination of coagulant(s) and flocculant(s). Figure 2 provides for a prospective pattern of coagulant and flocculant dosage in pH modulated coagulation-flocculation in comparison to coagulation-flocculation approach and pH induced flocculation approach individually. Further, Figure 3 illustrates the prospective cost analysis upon employing pH modulated coagulation- flocculation approach for separating solid particles from a fluid body including but not limiting to fresh water and marine water, when compared to coagulation-flocculation approach and pH induced flocculation approach for said separation.

In an exemplary embodiment, the coagulant dosage upon employing the pH modulated coagulation-flocculation approach is reduced significantly when compared to only using the unique combination of coagulant(s) and flocculant(s).

In an exemplary embodiment, the percentage recovery of said solid particles from a fluid body upon employing pH modulated coagulation-flocculation approach is at least 95%.

In an exemplary embodiment, the present disclosure relates to a method of separating solid particles, including but not limiting to living organisms from a non-limiting fluid body such as fresh water and marine water by employing pH modulation followed by unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s) of present disclosure through a process of coagulation and flocculation, wherein the said combination in the said method comprises single dosage or multiple dosage of either any or both of coagulant(s) and flocculant(s), respectively.

In a non-limiting embodiment, the instant method provides for modulating pH and combining the chemicals including but not limiting to coagulant(s) and flocculants(s) in any sequence and for any time period thereof within the scope of this disclosure. Said process of combining of chemicals including but not limiting to coagulant(s) and flocculants(s) and pH modulation provides separation of solid particles from fluid body including but not limiting to fresh water and marine water, through process of chemical coagulation and chemical flocculation and pH modulation and involves plurality of coagulant(s) and/or flocculants(s).

In a non-limiting embodiment, the present disclosure provides for a method of pH modulation followed by coagulation and flocculation for separation of solid particles including but not limiting to living organisms from a fluid body including but not limiting to fresh water and marine water, wherein said method comprises non-limiting acts of-
a. modulating pH of the fluid body;
b. contacting at least one coagulant(s) with the fluid body of step (a) in one or more dosages, and mixing the fluid body, followed by contacting at least one flocculant(s) with said fluid body and subjecting to further mixing;
c. reducing or stopping the mixing and allowing the fluid body to settle post the mixing or optionally subjecting the fluid body to a process including but not limiting to air flotation and/or filtration for efficient separation of the solid particles.

In a non-limiting embodiment, the present disclosure provides for a method of pH modulation followed by coagulation and flocculation for separation of solid particles including but not limiting to living organisms, from a fluid body including but not limiting to fresh water and marine water, wherein said method comprises non-limiting acts of-
a. modulating pH of the fluid body;
b. contacting first coagulant(s) with the fluid body of step (a) in one or more dosages, and mixing the fluid body followed by subjecting the mixed fluid body to contacting with second coagulant(s);
c. further mixing the fluid body and subjecting said fluid body to contacting with flocculant(s) and mixing;
d. reducing or stopping the mixing and allowing the fluid body to settle post the mixing or optionally subjecting the fluid body to a process including but not limiting to air flotation and/or filtration for efficient separation of the solid particles.

In a non-limiting embodiment, the above described methods of the present disclosure include a mixing of fluid body with chemicals but not limiting to coagulant(s) and flocculant(s), wherein single or multiple dosage of chemicals are added. Such mixing is carried out by any known or conventional technique that a person of average skill in the art deems fit. The said mixing is carried out for predetermined duration and at predetermined speed. For organisms including living organisms such as algae, preferably, the duration ranges from about 10 seconds to about 10 minutes, and the speed of said mixing ranges from about 40rpm to about 400rpm.

In another non-limiting embodiment, duration and speed of mixing in the above described methods may be determined by and/or depended on presence or absence of optional process which include but are not limited to air flotation and/or filtration, wherein these process(s) are optionally employed in the instant method for efficient separation of said solid particles including but not limiting to living organisms.

In another alternative embodiment of the present disclosure, the above described methods of separating solid particles by employing the unique combination of chemicals including but not limiting to coagulant(s) and flocculant(s) of present disclosure through a process of coagulation and flocculation is further optimized by combining above said coagulation and flocculation with both electro-coagulation and pH modulation techniques as described in the disclosure. The processes of pH modulation, electric impetus and combination of said chemicals in the instant method are employed in either a predetermined sequence or in any order thereof within the scope of this disclosure.

The present disclosure herein below provides for certain prophetic illustrations for better understanding of the instant invention. For the purpose of the illustration of separating solid particles from a fluid body including but not limiting to fresh water and marine water, algae is used as a model organism. However, person skilled in the art would be aware that the illustrations provided herein are only prospective in nature and can be extrapolated to any type of solid particles including but not limiting to organic and inorganic matter with modifications which fall under the purview of instant disclosure.

Illustration 1:
A fluid body comprising solid particles such as microorganisms (e.g., an algal culture) if treated with the combinatorial dose of coagulant and flocculant as described in the instant disclosure for harvesting or separation of said microorganism from the fluid body can result in a reduced dosage of coagulant. Initially a cationic coagulant may be added to the fluid body comprising the microorganism, thereby destabilizing the microorganism suspension to form pin flocks by virtue of charge neutralization. Thereafter an anionic flocculant may be added to bind microorganism pin flocks into large flocks.

For instance, if green algae from an outdoor open race way is to be harvested or separated from a fluid body, coagulant dosage can be reduced to about 150ppm to about 250ppm upon combinatorial addition of coagulant and flocculant employed in the instant disclosure. On the other hand, to harvest or separate unialgal green algae from a fluid body, through combinatorial addition of coagulant and flocculant employed in the instant method, coagulant dosage can be reduced to about 30ppm to about 50ppm, when compared to the dosages, which may be as high as 10,000ppm or even higher, of coagulant in general harvesting or separating procedures. Further, the flocculant dosage in the above described harvesting or separation can be presumed to be in the range of about 1.0ppm to about 2.0ppm.

Illustration 2:
A fluid body comprising solid particles such as microorganisms (e.g. algal culture), if treated with a hybrid electro-coagulation approach of the present disclosure, it is believed that the coagulant dosage can be reduced during separation or harvesting of the microorganism, when compared to pure chemical approach.

For instance, if fluid body comprising filamentous BGA is treated with the hybrid electro-coagulation, the coagulant dosage can be presumed to be reduced to about 0ppm. Similarly, for green algae the coagulant dosage can be presumed to be reduced to about 0ppm, whereas for non-filamentous BGA, the coagulant dosage can be presumed to be reduced to about 100ppm.

Illustration 3:
A fluid body comprising solid particles such as microorganisms (e.g. an algal culture) if treated with pH modulated coagulation-flocculation approach of the present disclosure, it is believed that the coagulant dosage can be expected to be reduced to about 2 to 3 times when compared to only chemical coagulation-flocculation approach. It can be presumed that modulating pH of the fluid body by addition of NaOH and maintaining the pH towards alkalinity reduces the consumption of coagulant during separation or harvesting of microorganism (e.g. algal culture). The prospective alkaline pH presumed to reduce the coagulant consumption is in the range of about 8.5 to about 11. The prospective pattern of chemical consumption during pH modulated coagulation-flocculation and only coagulation-flocculation approach and pH induced flocculation is exemplified in Figure 2.

Hypothetically, for a fluid body comprising virgin culture subjected to pH modulated coagulation-flocculation approach, it can presumed that the coagulant dosage will be reduced to about 50ppm when compared to 150ppm during coagulation-flocculation approach.

Illustration 4:
This illustration provides for cost effectiveness of the pH modulated coagulation-flocculation based on illustration 3 and a presumption that there will be a considerable reduction in chemical consumption while separating solid particles by pH modulated coagulation-flocculation approach. The prospective cost analysis of the chemical consumption during pH modulated coagulation-flocculation approach is exemplified below in comparison to coagulation-flocculation approach and pH induced flocculation.

Below are the costs of chemicals assumed based on quotes from different vendors:
Average cost for Coagulant = INR 60.0 / Kg
Average cost for Flocculant = INR 120.0 / Kg
Average cost of NaOH = INR 30.0 / Kg.

• If a fluid body comprising solid particles such as microorganism (e.g. a virgin algal cultural) is treated with only chemical coagulant-flocculant combination, wherein the pH of the culture is maintained similar to the original virgin algae culture pH i.e. 9.35, the cost of harvesting will approximately be Rs. 9/L of such fluid body with short sedimentation time of <30 seconds.

• If the pH of the fluid body comprising such a microorganism (e.g. a virgin algal cultural) is adjusted without addition of coagulant and flocculant, the cost of harvesting will approximately be Rs.20/L of such fluid body, when the pH of the culture is adjusted to 10.1, wherein it is likely to be accompanied by long sedimentation time in the range of about 30 to about 40 min. On the other hand, the cost of harvesting will approximately be Rs.65 Rs/L of such fluid body when the pH of the culture is adjusted to 10.5 without addition of coagulant and flocculant, wherein it is likely to be accompanied by short sedimentation time of <30 seconds.

• If the microorganisms (e.g. algal culture) is subjected to pH modulated coagulation-flocculation approach of the present disclosure, and wherein pH of the fluid body comprising an algal culture is initially adjusted to a pH of about 9.7 to about 10.0, followed by addition of coagulant(s) and flocculant(s) of the present disclosure, the cost of harvesting will approximately be under Rs.5/L.

Thus, in conclusion from the above analysis, it can be inferred that pH modulated coagulation-flocculation approach may result in cost savings of about 2 folds in comparison to chemical coagulation-flocculation approach, and about 4 to about 12 folds in comparison to only pH based flocculation. The prospective cost effectiveness of pH modulated coagulation-flocculation approach is exemplified in Figure 3.

The present disclosure in view of the above described illustrations and various embodiments, is thus able to successfully overcome the various deficiencies of prior art and provide for an improved method for separating solid particles, wherein suitable examples of the solid particles are living organisms, such as autotrophic organisms, preferably phototrophic organisms including but not limiting to algae from their environment, such as a fluid body including but not limiting to fresh water and marine water. Alternatively, the methods of present disclosure illustrates separation of solid particles including but not limiting to organic or inorganic matter from a fluid body, including but not limiting to fresh water and marine water.

As used within the purview of the instant description, ‘fluid body’ means any surface comprising a liquid or gaseous matter or a combination thereof and is capable of supporting growth of any organic matter or living organism, preferably autotrophic, more preferably phototrophic organisms and dwelling non-living matter.

As used within the purview of the instant description, ‘solid particle’ means any living or non-living matter capable of dwelling in a fluid body. The suitable examples of a solid particles is living organisms, preferably autotrophic, more preferably phototrophic organisms including but not limiting to algae, protists, phytoplankton and cyanobacteria,

Additional embodiments and features of the present disclosure will be apparent to one of ordinary skill in art based on the description provided herein. The embodiments herein provide various features and advantageous details thereof in the description. Descriptions of well-known/conventional methods and techniques are omitted so as to not unnecessarily obscure the embodiments herein.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments in this disclosure have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising” wherever used, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.