Description:DESCRIPTION:
Field of the invention:
[0001] The present disclosure generally relates to the technical field of wastewater treatments, and in specific relates to a magnetite-based green microalgae nano-composite for the treatment of wastewater and degrading insecticide.
Background of the invention:
[0002] Water contamination is a major environmental challenge caused by human activities. Water contamination can cause a variety of health problems, including diarrhea, cholera, and typhoid fever. Wastewater is a major source of water contamination and contains pollutants that can harm the environment. Wastewater is produced from many different sources, including home, institutional, industrial, commercial, and agricultural, and contains a variety of pollutants that harm the environment's natural balance. Several methods are utilized to reduce water contamination. These methods include treating wastewater before releasing the wastewater into the environment, reducing the use of pesticides and fertilizers, encouraging people to recycle and compost, and protecting water resources from pollution.

[0003] At present, there are many treatment techniques available for water treatment. These techniques are broadly classified into three categories: primary, secondary, and tertiary treatment. Primary treatment is the first stage of water treatment. The primary treatment is performed to remove large particles from the water, such as sand, dirt, and grit. The removal of large particles is done through sedimentation, which is the process of allowing the particles to settle into the bottom of a tank.

[0004] Secondary treatment is the second stage of water treatment. In the secondary treatment, dissolved organic matter is removed from the water. The removal of dissolved organic matter is done through a process called coagulation and flocculation. In coagulation, chemicals are added to the water to cause the dissolved organic matter to clump together. In flocculation, the clumps of organic matter are allowed to settle to the bottom of a tank.

[0005] Tertiary treatment is the third stage of water treatment. In tertiary treatment, specific pollutants are removed from the water, such as nutrients (phosphorus and nitrogen) and heavy metals. The removal of the specific pollutants is done through a variety of processes, such as aerobic and anaerobic digestion.

[0006] Phosphorus and nitrogen are essential nutrients for all forms of life on Earth. However, excess levels of these nutrients can disrupt the natural environment. When nutrients enter surface water bodies, they can fuel the growth of harmful algae. This process, called eutrophication, can lead to the death of fish and other aquatic life. Wastewater can contaminate water and pose serious problems for aquatic life. Nutrient pollution, which is caused by the presence of excess phosphorus and nitrogen in water, is a major problem in both developed and developing nations. This pollution can lead to the growth of harmful algae, which can degrade water quality, consume dissolved oxygen, and cause environmental problems.

[0007] There exists a variety of techniques available for removing phosphorus and nitrate from wastewater. These techniques can be divided into three main groups: physical, chemical, and biological. Physical techniques, such as sedimentation and filtration, are relatively inexpensive but can be less effective than chemical or biological techniques. Chemical techniques, such as ion exchange and precipitation, are more effective but can be more expensive. Biological techniques, such as activated sludge and trickling filters, are the most effective but can also be the most expensive. Therefore, the existing techniques available for removing contamination from the wastewater are either less effective or expensive.

[0008] Therefore, there is a need for a method to remove the insecticides and other pollutants from the effluents released into the environment. There is also a need for a nanocomposite comprising of electrochemical sludge and green microalgae that degrades insecticides belonging to an organophosphorus group. There is also a need for a method of treating agricultural effluents to remove the pollutants under optimum conditions.

Objectives of the invention:
[0009] The primary objective of the invention is to provide magnetite-based green microalgae nano-composite for the treatment of wastewater and degrading insecticide.

[0010] The other objective of the invention is to provide a method that can reuse the solid waste and synthesize it into the magnetite-based green microalgae nano-composite to degrade the toxic pollutants.

[0011] The other objective of the invention is to provide a method that can remove the insecticides and other pollutants from the effluents released into the environment.

[0012] Another objective of the invention is to provide a method for treating agricultural effluents to remove the pollutants under optimum conditions.

[0013] The other objective of the invention is to provide a magnetite-based green microalgae nano-composite that can be discarded into the environment, as the toxic is been converted into non-toxic compounds.
Summary of the invention:
[0014] The present disclosure proposes a magnetite-based green microalgae nano-composite and method of synthesising the same. The following presents a simplified summary in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview. It is not intended to identify key/critical elements or to delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

[0015] In order to overcome the above deficiencies of the prior art, the present disclosure is to solve the technical problem to provide a magnetite-based green microalgae nano-composite for the treatment of wastewater and degrading insecticide.

[0016] According to an aspect, the invention provides a magnetite-based green microalgae nano-composite that is effective for the treatment of wastewater and degrading insecticide. The magnetite-based green microalgae nano-composite comprises 80 to 87 weight percentage of a green microalgae powder and 13 to 20 weight percentage of an electrochemical sludge. In specific, the electrochemical sludge comprises magnetite (Fe3O4). The green micro algae is (MTCC-2581)-pseudomonus auriginosa.

[0017] According to another aspect, the invention provides a method for the preparation of a magnetite-based green microalgae nano-composite. At first, electrochemical sludge is mixed with green microalgae powder at a ratio of 1:5 in distilled water to obtain a sludge-algae mixture. In specific, green microalgae is vacuum dried for a time period of 72 hours to remove the water contains and obtain the green microalgae powder.

[0018] Next, the sludge-algae mixture is stirred for a time period of 5 hours at room temperature to obtain the magnetite-based green microalgae nano-composite. Next, the magnetite-based green microalgae nano-composite is dried at room temperature for a time period of 72 hours to obtain a dried solid nano-composite. Later, the dried solid nano-composite is ground into a nano-composite powder. Further, the nano-composite powder is stored in an air-tight container.

[0019] According to another aspect, the invention provides a method for the preparation of the electrochemical sludge. At first, a sewage sludge mixture is subjected to an electrocoagulation process for removing phosphate to obtain an electro-coagulated sludge mixture. Later, the electro-coagulated sludge mixture is kept still for a certain period of time resulting in a solid-liquid separation. Next, the electro-coagulated sludge mixture is subjected to a centrifugation process to remove excess liquid from the electro-coagulated sludge mixture to obtain solid sludge. Next, the solid sludge dried at a temperature of 100°C for a time period of 2 hours to obtain the electrochemical sludge.

[0020] Further, objects and advantages of the present invention will be apparent from a study of the following portion of the specification, the claims, and the attached drawings.

Detailed description of drawings:
[0021] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and, together with the description, explain the principles of the invention.

[0022] FIG. 1 illustrates a flowchart of a method for preparation of an electrochemical sludge, in accordance to an exemplary embodiment of the invention.

[0023] FIG. 2 illustrates a flowchart of a method for the preparation of a magnetite-based green microalgae nano-composite, in accordance to an exemplary embodiment of the invention.

[0024] FIG. 3 illustrates a graphical representation of the effect of agitation time on the percentage (%) degradation of malathion by the magnetite-based green microalgae nano-composite, in accordance to an exemplary embodiment of the invention.

[0025] FIG. 4 illustrates a graphical representation of the effect of pH on the percentage (%) degradation of malathion by the magnetite-based green microalgae nano-composite, in accordance to an exemplary embodiment of the invention.

[0026] FIG. 5 illustrates a graphical representation 500 of the effect of dosage on percentage (%) degradation of malathion by the magnetite-based green microalgae nano-composite, in accordance to an exemplary embodiment of the invention.

[0027] FIG. 6 a graphical representation 600 of the effect of initial concentration on percentage (%) degradation of malathion and catalyst capacity, in accordance to an exemplary embodiment of the invention.

[0028] FIG. 7 illustrates a graphical representation of the effect of temperature on the percentage (%) degradation of malathion by the magnetite-based green microalgae nano-composite, in accordance to an exemplary embodiment of the invention.

Detailed invention disclosure:
[0029] Various embodiments of the present invention will be described in reference to the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps.

[0030] The present disclosure has been made with a view towards solving the problem with the prior art described above, and it is an object of the present invention to provide a magnetite-based green microalgae nano-composite for the treatment of wastewater and degrading insecticide.

[0031] According to an exemplary embodiment, the invention provides a magnetite-based green microalgae nano-composite that is effective for the treatment of wastewater and degrading insecticide. The magnetite-based green microalgae nano-composite comprises 80 to 87 weight percentage of green microalgae powder and 13 to 20 weight percentage of electrochemical sludge. In specific, the electrochemical sludge comprises magnetite (Fe3O4). The green micro algae is (MTCC-2581)-pseudomonus auriginosa.

[0032] According to another exemplary embodiment of the invention, FIG. 1 refers to a flowchart 100 of a method for the preparation of an electrochemical sludge. At step 102, a sewage sludge mixture is subjected to an electrocoagulation process for removing phosphate to obtain an electro-coagulated sludge mixture. Later, the electro-coagulated sludge mixture is kept still for a certain period of time resulting in a solid-liquid separation of the electro-coagulated sludge mixture. At step 104, the electro-coagulated sludge mixture is subjected to a centrifugation process to remove excess liquid from the electro-coagulated sludge mixture to obtain solid sludge. At step 106, the solid sludge dried at a temperature of 100°C for a time period of 2 hours to obtain the electrochemical sludge.

[0033] According to another exemplary embodiment of the invention, FIG. 2 refers to a flowchart 200 of a method for preparation of the magnetite-based green microalgae nano-composite. At step 202, electrochemical sludge is mixed with green microalgae powder at a ratio of 1:5 in distilled water to obtain a sludge-algae mixture. In specific, green microalgae is vacuum dried for a time period of 72 hours to remove the water contains and obtain the green microalgae powder.

[0034] At step 204, the sludge-algae mixture is stirred for a time period of 5 hours at room temperature to obtain the magnetite-based green microalgae nano-composite. At step 206, the magnetite-based green microalgae nano-composite is dried at room temperature for a time period of 72 hours to obtain a dried solid nano-composite. At step 208, the dried solid nano-composite is ground into a nano-composite powder. Further, the nano-composite powder is stored in an air-tight container. In specific, the nano-composite powder is a dried and powder form of the magnetite-based green microalgae nano-composite.

[0035] In an embodiment, the nano-composite powder comprises the electrochemical sludge (metal Oxide) and the green microalgae- (MTCC-2581)-pseudomonus auriginosa that degrades insecticides belonging to an organophosphorus group.

[0036] In another embodiment, the nano-composite powder is utilized for treating an agricultural effluent. For example, the agricultural effluent is collected from an agricultural field. Further, discharged wastewater is collected. The agricultural effluent is filtered to remove lighter materials from the agricultural effluent to obtain then the agricultural effluent is used for the treatment with the nano-composite powder.

[0037] In specific, a predetermined quantity of the nano-composite powder is mixed with a predetermined quantity of the agricultural effluent to degrade the insecticide and shake for a predetermined time period at a predetermined temperature and a predetermined pH. The insecticides that are degraded by the nano-composite powder belong to the organophosphorus group. Insecticides are degraded by the nano-composite powder. Further, phosphate is absorbed by the nano-composite powder.

[0038] According to another exemplary embodiment of the invention, FIG. 3 refers to a graphical representation 300 of the effect of agitation time on percentage (%) degradation of malathion by the magnetite-based green microalgae nano-composite. To determine the optimum agitation time for the degradation of malathion by the magnetite-based green microalgae nano-composite, six agricultural effluent samples are prepared in conical flasks. Each agricultural effluent sample is of at least 50 mL and contained 0.1 g of the magnetite-based green microalgae nano-composite. The flasks are shaken for different time periods: 5, 10, 15, 20, 25, and 30 minutes. After each agitation time, the agricultural effluent samples are centrifuged and the supernatant is analyzed for malathion concentration.

[0039] The temperature and dosage of the magnetite-based green microalgae nano-composite are kept constant at 30°C and 0.1 g per 1000 mL, respectively. The results showed that the percentage degradation of malathion increased with agitation time, reaching a maximum of 82.48% after 30 minutes. This suggests that the optimum agitation time for the degradation of malathion by the magnetite-based green microalgae nano-composite is 30 minutes.

[0040] FIG. 3 shows that the %degradation of malathion gradually increases over the first 5 minutes of agitation, and continues to increase until 30 minutes. After 30 minutes, the % degradation gradually decreases. This suggests that the equilibrium agitation time for malathion degradation is 30 minutes. The initial increase in the % degradation is due to the fact that the magnetite-based green microalgae nano-composite has a large surface area that is available for the degradation of malathion. As time increases, the substrate (malathion) is deactivated and the removal rate decreases. The percentage degradation of malathion after a time period of 30 minutes is 82.48%.

[0041] According to another exemplary embodiment of the invention, FIG. 4 refers to a graphical representation 400 of the effect of pH on the percentage (%) degradation of malathion by the magnetite-based green microalgae nano-composite. The optimum pH for the degradation of malathion is determined by adjusting the pH of the six conical flasks to different values in the range of 4 to 10. The pH is adjusted using 0.1 N HCl and 0.1 N NaOH. 50 mL of the agricultural effluent is added to each flask and the flasks are shaken for a time period of 30 minutes.

[0042] The concentrations of malathion in the supernatants of the flasks are then measured at their respective wavelengths. The results showed that the optimum pH for the degradation of malathion is 6.0. At this pH, the concentration of malathion in the supernatant is 50% lower than the initial concentration. The degradation of malathion is lower at both lower and higher pH values.

[0043] The effect of pH on the degradation of malathion is studied at a temperature of 30°C, agitation time of 30 minutes, and catalyst dosage of 0.1 g per 1000 mL. The pH is varied from 4 to 10. The results showed that the percentage degradation of malathion increased as the pH increased from 4 to 7. The percentage degradation then decreased as the pH increased above 7. For a typical experiment with 50 mL of aqueous solution, the percentage degradation increased from 59.42% to 82.48% as the pH increased from 4 to 7. This suggests that the optimum pH for the degradation of malathion is in the range of 6 to 7.

[0044] According to another exemplary embodiment of the invention, FIG. 5 refers to a graphical representation 500 of the effect of dosage on the percentage (%) degradation of malathion by the magnetite-based green microalgae nano-composite. About 50 mL of the agricultural effluent sample with an optimum pH is taken in five individual conical flasks. Different amounts of adsorbent (0.06 g, 0.08 g, 0.1 g, 0.12 g, and 0.14 g) are added to the five conical flasks simultaneously. The conical flasks are then kept for shaking in a shaker for about 30 minutes. The supernatant is collected for each sample, and the concentrations of the selected insecticide are measured at their respective wavelengths.

[0045] The % degradation is increased from 30.32 % to 82.48 % as the dosage is increased from 0.02 to 0.1 g/L. The % degradation from the aqueous phase decreases from 82.48 % to 23.34% with an increase in the dosage amount from 0.1 to 0.18 g/L. This is so because, with less amount of catalyst, the amount of malathion is much more such that there are not enough surfaces where malathion could bind onto. While at higher catalyst concentration, all available sites are not utilized causing agglomeration of the catalyst which in turn decreases the number of adsorption sites available.

[0046] According to another exemplary embodiment of the invention, FIG. 6 refers to a graphical representation 600 of the effect of initial concentration on percentage (%) degradation of malathion and catalyst capacity. About 50 ml of agricultural effluent sample with different concentrations is taken in individual conical flasks. Different amounts of concentration from 10 to 100 mg/L are added to the above conical flasks simultaneously. Next, the conical flasks are kept for shaking in a shaker for a time period of 30 minutes with 0.1 g/L dosage of the composite at 303K. The supernatant is collected for each sample and the concentrations of the selected insecticide are noticed at their respective wavelength.

[0047] The %degradation of malathion in an aqueous solution decreases as the initial concentration of malathion increases. When the initial concentration of malathion is 10 mg/L, the percentage degradation is 98.85%. When the initial concentration of malathion is 100 mg/L, the percentage degradation is only 59.82%. This suggests that a higher initial concentration of malathion makes it more difficult to degrade. The reason for this is that the higher initial concentration of malathion means that there is more malathion present in the solution. This makes it more difficult for the degradation process to reach all of the malathion molecules. As a result, a lower percentage of malathion is degraded.

[0048] According to another exemplary embodiment of the invention, FIG. 7 refers to a graphical representation 700 of the effect of temperature on percentage (%) degradation of malathion by the magnetite-based green microalgae nano-composite. The pH, initial concentration, and dosage are kept at optimum values. Four conical flasks containing about 50 mL of agricultural effluent sample are incubated at different temperatures. The supernatant is collected for each sample, and the concentrations of the selected insecticide are measured at their respective wavelengths.

[0049] The % degradation of insecticide from the agricultural effluents is calculated from the formula given below. The Box Behnken Design (BBD) is used to optimize the data.

[0050] Where C0 is the Initial concentration of malathion in aqueous solution. Ct is the final concentration of malathion first 5 min of agitation time.

[0051] Amount of malathion adsorbed per unit mass of the magnetite-based green microalgae nano-composite, qe mg/g:

[0052] Where C0 stands for the initial concentration of malathion (mg/L), Ct stands for the final concentration of malathion (mg/L), V stands for the volume of the effluent taken (L), m stands for the mass of the magnetite-based green microalgae nano-composite (g), and q stands for amount of malathion, degraded by the magnetite based green microalgae nano-composite (mg/g).

[0053] The effect of temperature is studied at 303 to 318 K with dosage, agitation time, pH, and initial concentration being at 0.1 g, 30 min, and 50 ppm respectively. When the temperature increases, the % degradation of malathion also increases. The substrate deactivates after 45˚C.

[0054] Table 1:
Variable BBD Experimental
pH of an aqueous solution 6.669 7
Dosage, w, g/L 0.0918 0.1
Agitation time, min 27.356 30
% degradation 83.24 82.48

[0055] Table 1 depicts a comparison between optimum values from BBD and experimentation data.

[0056] Numerous advantages of the present disclosure may be apparent from the discussion above. In accordance with the present disclosure, a magnetite-based green microalgae nano-composite is disclosed for the treatment of wastewater and degrading insecticide.

[0057] The proposed method reuses the solid waste and synthesizes it into the magnetite-based green microalgae nano-composite to degrade the toxic pollutants. The proposed method removes the insecticides and other pollutants from the effluents released into the environment. The method for treating agricultural effluents to remove the pollutants under optimum conditions. Further, the used magnetite-based green microalgae nano-composite can again be discarded into the environment, as the toxic is been converted into non-toxic compounds.

[0058] It will readily be apparent that numerous modifications and alterations can be made to the processes described in the foregoing examples without departing from the principles underlying the invention, and all such modifications and alterations are intended to be embraced by this application.

, Claims:CLAIMS:
I / We Claim:
1. A magnetite-based green microalgae nano-composite, comprising:
80 to 87 weight percentage of a green microalgae powder; and
13 to 20 weight percentage of an electrochemical sludge,
whereby, the magnetite-based green microalgae nano-composite is effective for the treatment of wastewater and degrading insecticide.
2. The magnetite-based green microalgae nano-composite as claimed in claim 1, wherein the electrochemical sludge comprises magnetite (Fe3O4).
3. The magnetite-based green microalgae nano-composite as claimed in claim 1, wherein the green microalgae is (MTCC-2581)-pseudomonus auriginosa.
4. A method for preparation of a magnetite-based green microalgae nano-composite, comprising:
mixing an electrochemical sludge with a green microalgae powder at a ratio of 1:5 in distilled water to obtain a sludge-algae mixture;
stirring the sludge-algae mixture for a time period of 5 hours at room temperature to obtain the magnetite-based green microalgae nano-composite; and
drying the magnetite-based green microalgae nano-composite at room temperature for a time period of 72 hours to obtain dried solid nano-composite, grinding the dried solid nano-composite into a nano-composite powder.
5. The method for preparation of a magnetite-based green microalgae nano-composite as claimed in claim 4, wherein a method for preparation of the electrochemical sludge comprises:
subjecting a sewage sludge mixture through an electrocoagulation process for removing phosphate to obtain an electro-coagulated sludge mixture, wherein the electro-coagulated sludge mixture is kept still for a certain period of time resulting in a solid-liquid separation;
subjecting the electro-coagulated sludge mixture through a centrifugation process to remove excess liquid from the electro-coagulated sludge mixture to obtain a solid sludge; and
drying the solid sludge at a temperature of 100°C for a time period of 2 hours to obtain the electrochemical sludge.
6. The method for preparation of a magnetite-based green microalgae nano-composite as claimed in claim 4, wherein a green microalgae is vacuum dried for a time period of 72 hours to remove water contains and obtain the green microalgae powder.
7. The method for preparation of a magnetite-based green microalgae nano-composite as claimed in claim 4, wherein the magnetite-based green microalgae nano-composite is utilized to degrade either insecticides or pesticides that belong to either organophosphorus group or organochlorine group.
8. The method for preparation of a magnetite-based green microalgae nano-composite as claimed in claim 4, wherein a predetermined quantity of the magnetite-based green microalgae nano-composite is mixed with a predetermined quantity of an agricultural effluent to degrade from toxic to non-toxic component and shaking for a predetermined time period at a predetermined temperature and a predetermined pH.