AN IMPROVED DISINFECTION-SOLIDIFICATION PROCESS FOR PATHOGENIC MEDICAL WASTE DISPOSAL

Abstract

The present invention discloses an improved process for the efficient solidification of biomedical waste that is capable of simultaneously treating and disinfecting solid and fluid samples. The process comprises of the addition of the waste samples to an alkaline aqueous solution followed by the addition of a solid material at a defined volumetric and/or weighted composition leading to instantaneous solidification with >99.9% microbial disinfection and an all-in-one disinfecting device 10 for treatment of biomedical waste.

Claims

1. A process for disinfection followed by solidification by disinfection-solidification and disposal system, said process comprising the steps of adding disinfection composition comprising solid powders of a solidifying agent A and basifying agent B, wherein oxide based powders inter alia oxides of silicon, titanium, zinc or aluminium are added as solid powders from solidifying agent A, to an aqueous solution basified to an alkaline pH in the range of 9 to 14 using the basifying agent B containing the biomedical waste to be disinfected, wherein solid powders of the solidifying agent A is added at a minimum of 1% (w/v) and a maximum of 500% (w/v) of the total aqueous volume and the concentration of the basifying agent B is 1-90% w/v in water, more preferably >40% w/v in water.

2. The process as claimed in claim 1, wherein the solid powders of the solidifying agent A is silica powder with or without a binder, chromatography grade silica gel powder of 60-400 mesh size, alumina powder with or without a binder, chromatography grade alumina powder of 60-400 mesh size, titania powder with or without a binder, pigment grade titania in its rutile or anatase forms or a mixture of rutile and anatase forms, or zinc oxide powder with or without a binder, industrial grade zinc oxide in its powder form having particle size <500 m.

3. The process as claimed in claim 1, where the said basifying agent B is selected from hydroxides of alkali or alkaline earth metals selected from the group comprising of sodium or potassium hydroxide, basic salts of metals and organic cations, leading to a final pH in the range 9-14 in its aqueous solution.

4. The process for disinfection-solidification as claimed in claim 1, comprising the steps of: (a) preparation of an aqueous solution of basifying agent B in water; (b) addition of the biomedical waste to be disinfected to the said aqueous solution as prepared in step (a); (c) homogeneous mixing of the mixture obtained in step (b) and/or resting for 10-30 min; and (d) addition of solid powders of a solidifying agent A followed by mixing and/or resting, wherein the obtained mixture is characterized as solidified or gelled depending on the amounts of the solidifying agent A, basifying agent B and the biomedical waste.

5. The process for disinfection-solidification as claimed in claim 4, wherein in the amount of the biomedical waste added is less than 1:1000 (v/v) of basifying agent solution B for liquid waste and any immersible amount of solid waste or a mixture thereof.

6. The process for disinfection-solidification as claimed in claim 4, wherein solid powders of a solidifying agent A is added at a minimum of 1% (w/v) and a maximum of 500% (w/v) of the total aqueous volume in the mixture.

7. The process for disinfection-solidification as claimed in claim 4, wherein the biomedical waste used in step (b) is selected from the group consisting of salt, sugar, metal salts and complexes, aqueous waste, hospital chemicals such as iodine, saliva, urine, blood or any solid sample, inter alia cotton, tissue paper, needle, syringes or swabs alone or in combination thereof, whereby disinfection is effected by the high pH of basifying agent solution B.

8. The process for disinfection-solidification as claimed in claim 4, wherein the exothermic reaction between the solid powders of the solidifying agent A and the alkaline waste mixture provides a secondary thermal mechanism for pathogenic disinfection, said exothermicity is in the range 50-120 C.

9. A disinfection-solidification and disposal system filled with the disinfected composition as claimed in claim 1, the device comprising of: (a) an upper container or compartment system; (b) a middle container or compartment system; (c) a bottom container or compartment system; (d) a screw cap connected to the upper container or compartment system; (e) two breakable screw-caps, one connected between the upper and the middle container or compartment systems and another connected between the middle and the bottom container or compartment systems.

10. The disinfection-solidification and disposal system as claimed in claim 9, wherein the upper container or compartment system is filled with solid powder of the solidifying agent A.

11. The disinfection-solidification disposal system as claimed in claim 9, wherein the middle container or compartment system is filled with the biomedical waste.

12. The disinfection-solidification and disposal system as claimed in claim 9, wherein the bottom container or compartment system is filled with the aqueous solution of basifying agent B.

13. The disinfection-solidification and disposal system as claimed in claim 11, wherein the biomedical waste is solid or liquid waste or their mixture.

14. A disinfection composition comprising: a) solid powders of a solidifying agent A, wherein oxide based powders inter alia oxides of silicon, titanium, zinc or aluminium are added as solid powders from solidifying agent A; solid powders of the solidifying agent A is added at a minimum of 1% (w/v) and a maximum of 500% (w/v) of the total aqueous volume; and b) basifying agent B, wherein the concentration of the basifying agent B is 1-90% w/v in water, more preferably >40% w/v in water; wherein solid powders of a solidifying agent A is added to an aqueous solution basified to an alkaline pH in the range of 9 to 14 using the basifying agent B containing the biomedical waste to be disinfected.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0033] FIG. 1 illustrates the solidification process involving saturated salt (NaCl) solution upon addition of silica gel (chromatographic grade, 60-120 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL saturated salt solution, (c) 1 mL 50% aqueous NaOH+1 mL saturated salt solution and (d) after addition of silica gel for solidification.

[0034] FIG. 2 illustrates the solidification process involving saturated sugar (sucrose) solution upon addition of silica gel (chromatographic grade, 60-120 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL saturated sugar solution, (c) 1 mL 50% aqueous NaOH+1 mL saturated sugar solution and (d) after addition of silica gel for solidification.

[0035] FIG. 3 illustrates the solidification process involving a mixture of saturated salt (NaCl) and sugar (sucrose) solutions upon addition of silica gel (chromatographic grade, 60-120 mesh): (a) 1 mL 50% aqueous NaOH, (b) 0.5 mL saturated salt+0.5 mL saturated sugar solutions, (c) 1 mL 50% aqueous NaOH+1 mL saturated salt+sugar solutions and (d) after addition of silica gel for solidification.

[0036] FIG. 4 illustrates the solidification process involving 6% BSA solution upon addition of silica gel (chromatographic grade, 60-120 mesh): (a) 1 mL 50% aqueous NaOH, (b) 6% BSA solution, (c) 1 mL 50% aqueous NaOH+1 mL 6% BSA solution and (d) after addition of silica gel for solidification.

[0037] FIG. 5 illustrates the solidification process involving a mixture of saturated salt (NaCl) and 6% BSA solutions upon addition of silica gel (chromatographic grade, 60-120 mesh): (a) 1 mL 50% aqueous NaOH, (b) 0.5 mL saturated salt+0.5 mL 6% BSA solutions, (c) 1 mL 50% aqueous NaOH+1 mL saturated salt+6% BSA solutions and (d) after addition of silica gel for solidification.

[0038] FIG. 6 illustrates the solidification process involving saturated potassium dichromate solution upon addition of silica gel (chromatographic grade, 60-120 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL saturated potassium dichromate solution, (c) 1 mL 50% aqueous NaOH+1 mL saturated potassium dichromate solution and (d) after addition of silica gel for solidification.

[0039] FIG. 7 illustrates the solidification process involving iodine solution upon addition of silica gel (chromatographic grade, 60-120 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL iodine solution, (c) 1 mL 50% aqueous NaOH+1 mL iodine solution and (d) after addition of silica gel for solidification.

[0040] FIG. 8 illustrates the solidification process involving artificial blood upon addition of silica gel (chromatographic grade, 60-120 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL artificial blood, (c) 1 mL 50% aqueous NaOH+1 mL artificial blood and (d) after addition of silica gel for solidification. 6% BSA provided the protein content and heme was substituted with a iron(II) complex.

[0041] FIG. 9 illustrates the solidification process involving artificial urine upon addition of silica gel (chromatographic grade, 100-200 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL 50% aqueous NaOH+1 mL artificial urine and (c) after addition of silica gel for solidification.

[0042] FIG. 10 illustrates the solidification process involving artificial saliva upon addition of silica gel (chromatographic grade, 100-200 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL 50% aqueous NaOH+1 mL artificial saliva and (c) after addition of silica gel for solidification.

[0043] FIG. 11 illustrates the solidification process involving saturated salt (NaCl) solution upon addition of silica gel (chromatographic grade, 100-200 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL saturated salt solution, (c) 1 mL 50% aqueous NaOH+1 mL saturated salt solution and (d) after addition of silica gel for solidification.

[0044] FIG. 12 illustrates the solidification process involving saturated sugar (sucrose) solution upon addition of silica gel (chromatographic grade, 100-200 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL saturated sugar solution, (c) 1 mL 50% aqueous NaOH+1 mL saturated sugar solution and (d) after addition of silica gel for solidification.

[0045] FIG. 13 illustrates the solidification process involving 6% BSA solution upon addition of silica gel (chromatographic grade, 100-200 mesh): (a) 1 mL 50% aqueous NaOH, (b) 6% BSA solution, (c) 1 mL 50% aqueous NaOH+1 mL 6% BSA solution and (d) after addition of silica gel for solidification.

[0046] FIG. 14 illustrates the solidification process involving saturated potassium dichromate solution upon addition of silica gel (chromatographic grade, 100-200 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL saturated potassium dichromate solution, (c) 1 mL 50% aqueous NaOH+1 mL saturated potassium dichromate solution and (d) after addition of silica gel for solidification.

[0047] FIG. 15 illustrates the solidification process involving iodine solution upon addition of silica gel (chromatographic grade, 100-200 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL iodine solution, (c) 1 mL 50% aqueous NaOH+1 mL iodine solution and (d) after addition of silica gel for solidification.

[0048] FIG. 16 illustrates the solidification process involving artificial blood upon addition of silica gel (chromatographic grade, 230-400 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL artificial blood, (c) 1 mL 50% aqueous NaOH+1 mL artificial blood and (d) after addition of silica gel for solidification. 6% BSA provided the protein content and heme was substituted with a iron(II) complex.

[0049] FIG. 17 illustrates the solidification process involving artificial urine upon addition of silica gel (chromatographic grade, 100-200 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL 50% aqueous NaOH+1 mL artificial urine and (c) after addition of silica gel for solidification.

[0050] FIG. 18 illustrates the solidification process involving artificial saliva upon addition of silica gel (chromatographic grade, 100-200 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL 50% aqueous NaOH+1 mL artificial saliva and (c) after addition of silica gel for solidification.

[0051] FIG. 19 illustrates the solidification process involving saturated salt (NaCl) solution upon addition of silica gel (chromatographic grade, 230-400 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL saturated salt solution, (c) 1 mL 50% aqueous NaOH+1 mL saturated salt solution and (d) after addition of silica gel for solidification.

[0052] FIG. 20 illustrates the solidification process involving saturated sugar (sucrose) solution upon addition of silica gel (chromatographic grade, 230-400 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL saturated sugar solution, (c) 1 mL 50% aqueous NaOH+1 mL saturated sugar solution and (d) after addition of silica gel for solidification.

[0053] FIG. 21 illustrates the solidification process involving 6% BSA solution upon addition of silica gel (chromatographic grade, 230-400 mesh): (a) 1 mL 50% aqueous NaOH, (b) 6% BSA solution, (c) 1 mL 50% aqueous NaOH+1 mL 6% BSA solution and (d) after addition of silica gel for solidification.

[0054] FIG. 22 illustrates the solidification process involving saturated potassium dichromate solution upon addition of silica gel (chromatographic grade, 230-400 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL saturated potassium dichromate solution, (c) 1 mL 50% aqueous NaOH+1 mL saturated potassium dichromate solution and (d) after addition of silica gel for solidification.

[0055] FIG. 23 illustrates the solidification process involving iodine solution upon addition of silica gel (chromatographic grade, 230-400 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL iodine solution, (c) 1 mL 50% aqueous NaOH+1 mL iodine solution and (d) after addition of silica gel for solidification.

[0056] FIG. 24 illustrates the solidification process involving artificial blood upon addition of silica gel (chromatographic grade, 230-400 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL artificial blood, (c) 1 mL 50% aqueous NaOH+1 mL artificial blood and (d) after addition of silica gel for solidification. 6% BSA provided the protein content and heme was substituted with a iron(II) complex.

[0057] FIG. 25 illustrates the solidification process involving artificial urine upon addition of silica gel (chromatographic grade, 230-400 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL 50% aqueous NaOH+1 mL artificial urine and (c) after addition of silica gel for solidification.

[0058] FIG. 26 illustrates the solidification process involving artificial saliva upon addition of silica gel (chromatographic grade, 230-400 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL 50% aqueous NaOH+1 mL artificial saliva and (c) after addition of silica gel for solidification.

[0059] FIG. 27 illustrates the solidification process involving saturated potassium dichromate solution upon addition of alumina (chromatographic grade, basic, 60-325 mesh): (a) 1 mL 50% aqueous NaOH, (b) 1 mL saturated potassium dichromate solution, (c) 1 mL 50% aqueous NaOH+1 mL saturated potassium dichromate solution and (d) after addition of alumina for solidification.

[0060] FIG. 28 illustrates the solidification process involving saturated potassium dichromate solution upon addition of titania (mixture of anatase and rutile): (a) 1 mL 50% aqueous NaOH, (b) 1 mL saturated potassium dichromate solution, (c) 1 mL 50% aqueous NaOH+1 mL saturated potassium dichromate solution and (d) after addition of titania for solidification.

[0061] FIG. 29 illustrates the solidification process involving cotton pieces upon addition of silica gel (chromatographic grade): (a) 1 mL 50% aqueous NaOH+a piece of cotton, and after addition of silica gel for solidification: (b) 60-120 mesh, (c) 100-200 mesh and (d) 230-300 mesh.

[0062] FIG. 30 illustrates the solidification process involving tissue paper upon addition of silica gel (chromatographic grade): (a) 1 mL 50% aqueous NaOH+a piece of tissue paper, and after addition of silica gel for solidification: (b) 60-120 mesh, (c) 100-200 mesh and (d) 230-300 mesh.

[0063] FIG. 31 illustrates the solidification process involving needles upon addition of silica gel (chromatographic grade): (a) 1 mL 50% aqueous NaOH+a needle, and after addition of silica gel for solidification: (b) 60-120 mesh, (c) 100-200 mesh and (d) 230-300 mesh.

[0064] FIG. 32 illustrates the solidification process involving solid swabs upon addition of silica gel (chromatographic grade): (a) 1 mL 50% aqueous NaOH+a swab, and after addition of silica gel for solidification: (b) 60-120 mesh, (c) 100-200 mesh and (d) 230-300 mesh.

[0065] FIG. 33 illustrates the solidification process involving tissue paper upon addition of alumina (chromatographic grade, basic, 60-325 mesh): (a) 1 mL 50% aqueous NaOH+a piece of tissue paper, and (b) after addition of alumina for solidification.

[0066] FIG. 34 illustrates the solidification process involving tissue paper upon addition of titania (mixture of anatase and rutile): (a) 1 mL 50% aqueous NaOH+a piece of tissue paper, and (b) after addition of titania for solidification.

[0067] FIG. 35 illustrates the photographs of the Petri dishes cultured with the samples taken (A,D) as control, (B,E) after addition of aqueous NaOH and (C,F) after solidification of an aqueous solution of NaOH and bacterial broths containing (A-C) E. coli, and (D-F) S. aureus confirming complete disinfection in quantitative experiments.

[0068] FIG. 36 illustrates the large scale solidification process involving a mixture of solid and liquid wastes upon addition of silica gel (chromatographic grade): (a) a mixture of solid and liquid wastes in 50% aqueous NaOH and (b) after addition of silica gel (60-120 mesh) for solidification.

[0069] FIG. 37 illustrates a prototype of an all-in-one sample collection-disinfection-solidification-disposal device for liquid samples, (a) consisting of three collection vials mounted one on top of the other such that (b) the top vial contains solid material A (silica is shown as an example), the middle one with collected sample and the bottom one prefilled with the requisite amount of solution B. Once collected sample is tested, the remaining sample could be initially disinfected by allowing (c) the sample to mix with solution B by breaking the junction between middle and bottom compartments followed by (d) solidification via the addition of material A by breaking the junction between the top and middle compartments.

[0070] FIG. 38 illustrates a prototype of an all-in-one sample collection-disinfection-solidification-disposal device for solid samples, (a) consisting of two collection vials mounted one on top of the other such that (b) the top vial contains solid material A (silica is shown as an example), and the bottom one prefilled with the requisite amount of solution B. The waste sample could be initially disinfected by (c) mixing the sample with solution B followed by (d) solidification via the addition of material A by breaking the junction between the two compartments.

[0071] FIG. 39 illustrates the design of the prototype of an all-in-one sample collection-disinfection-solidification-disposal device for liquid samples as shown in FIG. 37.

[0072] FIG. 40 illustrates the design of the prototype of an all-in-one sample collection-disinfection-solidification-disposal device for solid samples as shown in FIG. 38.

DETAILED DESCRIPTION OF THE INVENTION

[0073] This section describes the present invention in preferred embodiments in detail. The attached illustrations/drawings are intended for the purpose of describing and understanding the preferred embodiments in detail and not to limit the invention or its scope or both thereto.

[0074] Upon extensive investigations, the inventors of the present invention previously found that adding a poly-amino acid as its aqueous solution to a stable nanomaterial sol in water leads to instantaneous flocculation and the said flocculation process could further be controlled to effect gelation or solidification under carefully controlled conditions. However, the use of sol and polyamino acids are not very effective for long term treatment and resting of biomedical waste and there is an urgent need to minimize the amount of water used, followed by reducing the number of chemical components. The present invention provides an improved process for the disinfection and solidification of pathogenic biomedical waste with reduced number of chemical components and minimal use of water.

[0075] The prime embodiment of the present subject matter provides an improved disinfectionsolidification process for the preparation for disposal of solid and fluid wastes collected in a collection vessel at point of care, combined with the destruction, disinfection or deactivation of infectious agents including microorganisms inter alia bacteria, fungus etc., viruses and other toxins, whereby the disposal including treatment, handling and transportation are deemed easier, safer and cost-effective.

[0076] Solidification reduces the risk of spills and aerosolization, whereas complete pathogenic disinfection allows to dispose of the wastes thereof as non-regulated medical waste, which is less expensive than red-bagging. Segregation, transportation and incineration of such disinfected medical wastes are easier, safer and decrease medical waste disposal costs for a healthcare facility.

[0077] Another embodiment of the present invention comprises of the addition of oxides of transition metals inter alia titanium, aluminium, silicon or or zinc, with or without a binder, added to an aqueous solution basified to an alkaline pH using a base B containing the biomedical entity to be disinfected, such that the concentration of B is 0.1-90% w/v in water, more preferably >40% w/v in water and solid A is added at a minimum of 1% (w/v) and a maximum of 500% (w/v) of the total aqueous volume, resulting in instantaneous disinfection followed by instantaneous solidification.

[0078] The present invention intends to offer a self-disinfecting solidification process for the treatment and disposal of biomedical waste. The treatment process disclosed herein involves a solidifying agent inter alia silica powder with or without a binder, chromatography grade silica gel powder of 60-400 mesh size, alumina powder with or without a binder, chromatography grade alumina powder of 60-200 mesh size, titania powder with or without a binder, pigment grade titania in its rutile or anatase forms or a mixture of rutile and anatase forms, or zinc oxide powder with or without a binder, industrial grade zinc oxide in its powder form having particle size <500 m, which when subjected to mixing with solid or fluid waste samples disinfected by adding to an alkaline solution of a base, at a defined volumetric and/or weighted composition leads to instantaneous solidification with up to 100% microbial disinfection.

[0079] In specific embodiments, the invention relates to providing a non-pourable environment for fluid medical wastes inter alia salt, sugar, saliva, urine, blood, hapital chemicals, etc. wherein risks related to spillage and occupational exposure are minimized, and further to the treatment of solid medical wastes inter alia cotton, tissue paper, swabs, needles, etc., wherein the risks related to accumulation of untreated and infected samples are minimized or a mixture of solid and liquid wastes added with >99.9% microbial disfection.

[0080] Another aspect of the present invention disclose the volumetric composition of an aqueous solution of a pH regulating base or alkali for complete disinfection of fluid or solid medical waste followed by the addition of an oxide based solid powder, as a single or plurality of the said powders, for instanteneous solidification of solid or fluid samples containing proteins, microbial cultures, salt or metal ions in high concentrations.

[0081] Another aspect of the present invention is directed to creating all-in-one sample collectiondisinfectionsolidification devices of requisite dimensions capable of collecting the solid or liquid sample, flocculating/gelating/solidifying the samples as and when required and disinfecting the same for preparation for its disposal. and immobilizing them as and when required with prior pathogenic disinfection for preparation for its disposal.

[0082] In an embodiment, the present invention provides a process for disinfection followed by solidification by disinfection-solidification and disposal system, said process comprising the steps of adding disinfection composition comprising solid powders of a solidifying agent A and basifying agent B, wherein oxide based powders inter alia oxides of silicon, titanium, zinc or aluminium are added as solid powders from solidifying agent A, to an aqueous solution basified to an alkaline pH in the range of 9 to 14 using the basifying agent B containing the biomedical waste to be disinfected, wherein solid powders of the solidifying agent A is added at a minimum of 1% (w/v) and a maximum of 500% (w/v) of the total aqueous volume and the concentration of the basifying agent B is 1-90% w/v in water, more preferably >40% w/v in water.

[0083] In yet another embodiment, the solid powders of the solidifying agent A is silica powder with or without a binder, chromatography grade silica gel powder of 60-400 mesh size, alumina powder with or without a binder, chromatography grade alumina powder of 60-400 mesh size, titania powder with or without a binder, pigment grade titania in its rutile or anatase forms or a mixture of rutile and anatase forms, or zinc oxide powder with or without a binder, industrial grade zinc oxide in its powder form having particle size <500 m.

[0084] Further, said basifying agent B is selected from hydroxides of alkali or alkaline earth metals selected from the group comprising of sodium or potassium hydroxide, basic salts of metals and organic cations, leading to a final pH in the range 9-14 in its aqueous solution.

[0085] In yet another embodiment, the present invention relates to a process for disinfection-solidification, comprising the steps of: [0086] (a) preparation of an aqueous solution of basifying agent B in water; [0087] (b) addition of the biomedical waste to be disinfected to the said aqueous solution as prepared in step (a); [0088] (c) homogeneous mixing of the mixture obtained in step (b) and/or resting for 10-30 min; and [0089] (d) addition of solid powders of a solidifying agent A followed by mixing and/or resting, wherein the obtained mixture is characterized as solidified or gelled depending on the amounts of the solidifying agent A, basifying agent B and the biomedical waste.

[0090] Further, the amount of the biomedical waste added is less than 1:1000 (v/v) of basifying agent solution B for liquid waste and any immersible amount of solid waste or a mixture thereof. The solid powders of a solidifying agent A is added at a minimum of 1% (w/v) and a maximum of 500% (w/v) of the total aqueous volume in the mixture.

[0091] In yet another embodiment of the present invention, the present invention relates to a process for disinfection-solidification, wherein the biomedical waste used in step (b) is selected from the group consisting of salt, sugar, metal salts and complexes, aqueous waste, hospital chemicals such as iodine, saliva, urine, blood or any solid sample, inter alia cotton, tissue paper, needle, syringes or swabs alone or in combination thereof, whereby disinfection is effected by the high pH of basifying agent solution B.

[0092] Further, the exothermic reaction between the solid powders of the solidifying agent A and the alkaline waste mixture provides a secondary thermal mechanism for pathogenic disinfection, said exothermicity is in the range 50-120 C.

[0093] In yet another embodiment, the present invention provides a disinfection-solidification and disposal system filled with the disinfected composition, the device comprising of: [0094] (a) an upper container or compartment system [1, FIG. 39]; [0095] (b) a middle container or compartment system [2, FIG. 39]; [0096] (c) a bottom container or compartment system [3, FIG. 39]; [0097] (d) a screw cap [4, FIG. 39] connected to the upper container or compartment system; [0098] (e) two breakable screw-caps [5, FIG. 39], one connected between the upper and the middle container or compartment systems and another connected between the middle and the bottom container or compartment systems.

[0099] Further, the upper container or compartment system is filled with solid powder of the solidifying agent A in the disinfection-solidification and disposal system. The middle container or compartment system is filled with the biomedical waste. The bottom container or compartment system is filled with the aqueous solution of basifying agent B. Further, the biomedical waste is solid or liquid waste or their mixture.

[0100] In yet another embodiment, the present invention provides a disinfection composition comprising: [0101] a) solid powders of a solidifying agent A, wherein oxide based powders inter alia oxides of silicon, titanium, zinc or aluminium are added as solid powders from solidifying agent A; solid powders of the solidifying agent A is added at a minimum of 1% (w/v) and a maximum of 500% (w/v) of the total aqueous volume; and [0102] b) basifying agent B, wherein the concentration of the basifying agent B is 1-90% w/v in water, more preferably >40% w/v in water; [0103] wherein solid powders of a solidifying agent A is added to an aqueous solution basified to an alkaline pH in the range of 9 to 14 using the basifying agent B containing the biomedical waste to be disinfected.

EXAMPLES

[0104] Following examples are given by way of illustration and therefore should not be construed to limit the scope of the invention.

Example 1. Solidification of Aqueous Waste Using Silica Gel Powder (60-120, 100-200 or 230-400 Mesh)

[0105] 50% NaOH solution was made in water. The aqueous waste (1:1) was added to the above solution and mixed well. Solid silica powder was added to effect instantaneous solidification.

Example 2. Solidification of Concentrated Salt Solution Using Silica Gel Powder (60-120, 100-200 or 230-400 Mesh)

[0106] 50% NaOH solution was made in water. A saturated aqueous solution of sodium chloride (1:1) was added to the above solution and mixed well. Solid silica powder was added to effect instantaneous solidification.

Example 3. Solidification of Concentrated Sugar Solution Using Silica Gel Powder (60-120, 100-200 or 230-400 Mesh)

[0107] 50% NaOH solution was made in water. A saturated aqueous solution of sucrose (1:1) was added to the above solution and mixed well. Solid silica powder was added to effect instantaneous solidification.

Example 4. Solidification of a Mixture of Concentrated Salt and Sugar Solutions Using Silica Gel Powder (60-120, 100-200 or 230-400 Mesh)

[0108] 50% NaOH solution was made in water. A mixture of saturated aqueous solutions of sodium chloride and sucrose (1:1) was added to the above solution and mixed well. Solid silica powder was added to effect instantaneous solidification.

Example 5. Solidification of Aqueous Waste Containing Proteins Using Silica Gel Powder (60-120, 100-200 or 230-400 Mesh)

[0109] 50% NaOH solution was made in water. A 6% aqueous solution of BSA (1:1) was added to the above solution and mixed well. Solid silica powder was added to effect instantaneous solidification. Full Form of BSA is Bovine Serum Albumin.

Example 6. Solidification of Concentrated Salt Solution Containing Proteins Using Silica Gel Powder (60-120, 100-200 or 230-400 Mesh)

[0110] 50% NaOH solution was made in water. A saturated aqueous solution of sodium chloride containing 6% BSA (1:1) was added to the above solution and mixed well. Solid silica powder was added to effect instantaneous solidification.

Example 7. Solidification of Aqueous Solution Containing Metal Ions and Harsh Oxidising Agent Using Silica Gel Powder (60-120, 100-200 or 230-400 Mesh)

[0111] 50% NaOH solution was made in water. A saturated aqueous solution of potassium dichromate (1:1) was added to the above solution and mixed well. Solid silica powder was added to effect instantaneous solidification.

Example 8. Solidification of Aqueous Waste Containing Hospital Chemicals Using Silica Gel Powder (60-120, 100-200 or 230-400 Mesh)

[0112] 50% NaOH solution was made in water. A concentrated aqueous solution of iodine (1:1) was added to the above solution and mixed well. Solid silica powder was added to effect instantaneous solidification.

Example 9. Solidification of Aqueous Wastes Using Alumina Powder (60-400 Mesh)

[0113] 50% NaOH solution was made in water. The aqueous waste as mentioned in examples 1-8 above (1:1) was added to the above solution and mixed well. Solid alumina powder was added to effect instantaneous solidification.

Example 10. Solidification of Aqueous Wastes Using Titania Powder (Mixture of Anatase and Rutile)

[0114] 50% NaOH solution was made in water. The aqueous waste as mentioned in examples 1-8 above (1:1) was added to the above solution and mixed well. Solid titania powder was added to effect instantaneous solidification.

Example 11. Solidification of Aqueous Wastes Using Zinc Oxide Powder (Particle Size <500 m)

[0115] 50% NaOH solution was made in water. The aqueous waste as mentioned in examples 1-8 above (1:1) was added to the above solution and mixed well. Solid zinc oxide powder was added to effect instantaneous solidification.

Example 12. Preparation of Artificial Saliva

[0116] Artificial saliva was prepared according to the following two procedures: (i) Mixing 1.5 mM Ca(NO.sub.3).sub.2, 0.90 mM KH.sub.2PO.sub.4, 130 mM KCl and 60 mM Tris buffer at pH 7.4 (Reference may be made to:Kirkham, J.;et al., Self-assembling peptide scaffolds promote enamel remineralization,J.Dental Res. 2007,86, 426-430). (ii) Mixing sodium chloride (0.06 g), potassium chloride (0.072 g), calcium chloride dihydrate (0.022 g), potassium dihydrogen phosphate (0.068 g), disodium hydrogen phosphate dodecahydrate (0.086 g), potassium thiocyanate (0.006 g), sodium hydrogen carbonate (0.15 g), and citric acid (0.003 g) in 100 mL distilled water at pH 6.5 (Reference may be made to:Duff, G. S.; et al., Development of an artificial saliva solution for studying the corrosion behavior of dental alloys. Corrosion 2004, 60,594-602).

Example 13. Solidification of Artificial Saliva Using Silica Gel Powder (60-120, 100-200 or 230-400 Mesh)

[0117] 50% NaOH solution was made in water. Artificial saliva (1:1) was added to the above solution and mixed well. Solid silica gel powder was added to effect instantaneous solidification.

Example 14. Solidification of Artificial Saliva Using Alumina Powder (60-400 Mesh)

[0118] 50% NaOH solution was made in water. Artificial saliva (1:1) was added to the above solution and mixed well. Solid alumina powder was added to effect instantaneous solidification.

Example 15. Solidification of Artificial Saliva Using Titania Powder (Mixture of Anatase and Rutile)

[0119] 50% NaOH solution was made in water. Artificial saliva (1:1) was added to the above solution and mixed well. Solid titania powder was added to effect instantaneous solidification.

Example 16. Solidification of Artificial Saliva Using Zinc Oxide Powder (Particle Size <500 m)

[0120] 50% NaOH solution was made in water. Artificial saliva (1:1) was added to the above solution and mixed well. Solid zinc oxide powder was added to effect instantaneous solidification.

Example 17. Preparation of Artificial Urine

[0121] To 75 mL of distilled water in a container, urea (1.82 g) was added and shaken well to dissolve. Sodium chloride (0.75 g), potassium chloride (0.45 g) and sodium phosphate (0.48 g) were further added to the above mixture and mixed well until dissolved. The pH was adjusted to be between 5 and 7. Creatinine (200 mg) and albumin powder (5 mg)were added and mixed gently. The artificial urine thus obtained was further spiked with a few mg of glucose before each experiment.

Example 18. Solidification of Artificial Urine Using Silica Gel Powder (60-120, 100-200 or 230-400 Mesh)

[0122] 50% NaOH solution was made in water. Artificial urine (1:1) was added to the above solution and mixed well. Solid silica gel powder was added to effect instantaneous solidification.

Example 19. Solidification of Artificial Urine Using Alumina Powder (60-400 Mesh)

[0123] 50% NaOH solution was made in water. Artificial urine (1:1) was added to the above solution and mixed well. Solid alumina powder was added to effect instantaneous solidification.

Example 20. Solidification of Artificial Urine Using Titania Powder (Mixture of Anatase and Rutile)

[0124] 50% NaOH solution was made in water. Artificial urine (1:1) was added to the above solution and mixed well. Solid titania powder was added to effect instantaneous solidification.

Example 21. Solidification of Artificial Urine Using Zinc Oxide Powder (Particle Size <500 m)

[0125] 50% NaOH solution was made in water. Artificial urine (1:1) was added to the above solution and mixed well. Solid zinc oxide powder was added to effect instantaneous solidification.

Example 22. Preparation of Artificial Blood

[0126] A 6% solution of BSA was prepared in distilled water. A small amount of an iron(II) complex was added to mimic heme and impart color. Full form of BSA is Bovine Serum Albumin.

Example 23. Solidification of Artificial Blood Using Silica Gel Powder (60-120, 100-200 or 230-400 Mesh)

[0127] 50% NaOH solution was made in water. Artificial blood (1:1) was added to the above solution and mixed well. Solid silica gel powder was added to effect instantaneous solidification.

Example 24. Solidification of Artificial Blood Using Alumina Powder (60-400 Mesh)

[0128] 50% NaOH solution was made in water. Artificial blood (1:1) was added to the above solution and mixed well. Solid alumina powder was added to effect instantaneous solidification.

Example 25. Solidification of Artificial Blood Using Titania Powder (Mixture of Anatase and Rutile)

[0129] 50% NaOH solution was made in water. Artificial blood (1:1) was added to the above solution and mixed well. Solid titania powder was added to effect instantaneous solidification.

Example 26. Solidification of Artificial Blood Using Zinc Oxide Powder (Particle Size <500 m)

[0130] 50% NaOH solution was made in water. Artificial blood (1:1) was added to the above solution and mixed well. Solid zinc oxide powder was added to effect instantaneous solidification.

Example 27. Immobilization of a Solid Swab in Silica Gel (60-400 Mesh), Alumina (60-400 Mesh), Titamia (Mixture of Anatase and Rutile) or Zinc Oxide (Particle Size <500 m) Powders

[0131] 50% NaOH solution was made in water in an 8 mL glass vial and a piece of swab (4 cm) was immersed. It was mixed well and solid powder of silica gel (60-400 mesh), alumina (60-400 mesh), titamia (mixture of anatase and rutile) or zinc oxide (particle size <500 m) was added, resulting in instantaneous solidification.

Example 28. Immobilization of a Syringe Needle in Silica Gel (60-400 Mesh), Alumina (60-400 Mesh), Titamia (Mixture of Anatase and Rutile) or Zinc Oxide (Particle Size <500 m) Powders

[0132] 50% NaOH solution was made in water in an 8 mL glass vial and a needle (4-6 cm) was immersed. It was mixed well and solid powder of silica gel (60-400 mesh), alumina (60-400 mesh), titamia (mixture of anatase and rutile) or zinc oxide (particle size <500 m) was added, resulting in instantaneous solidification.

Example 29. Immobilization of Cotton Waste in Silica Gel (60-400 Mesh), Alumina (60-400 Mesh), Titamia (Mixture of Anatase and Rutile) or Zinc Oxide (Particle Size <500 m) Powders

[0133] 50% NaOH solution was made in water in a glass vial and a piece of waste cotton was immersed. It was mixed well and solid powder of silica gel (60-400 mesh), alumina (60-400 mesh), titamia (mixture of anatase and rutile) or zinc oxide (particle size <500 m) was added, resulting in instantaneous solidification.

Example 30. Immobilization of Tissue Paper in Silica Gel (60-400 Mesh), Alumina (60-400 Mesh), Titamia (Mixture of Anatase and Rutile) or Zinc Oxide (Particle Size <500 m) Powders

[0134] 50% NaOH solution was made in water in a glass vial and a piece of tissue paper was immersed. It was mixed well and solid powder of silica gel (60-400 mesh), alumina (60-400 mesh), titamia (mixture of anatase and rutile) or zinc oxide (particle size <500 m) was added, resulting in instantaneous solidification.

Example 31. Immobilization of Large Scale Mixed Waste in Silica Gel (60-400 Mesh), Alumina (60-400 Mesh), Titamia (Mixture of Anatase and Rutile) or Zinc Oxide (Particle Size <500 m) Powders

[0135] 50% NaOH solution was made in water in a glass beaker and a mixture of different wastes (solid and liquidsyringe, needle, swab, cotton, tissue, artificial urine, blood and saliva, iodine, potassium dichromate, salt, sugar, etc.) was added. It was mixed well and solid powder of silica gel (60-400 mesh) was added, resulting in instantaneous solidification.

Example 32. Antimicrobial Studies

[0136] Cultures of Escherichia coli and Staphylococcus aureus were prepared in Luria Bertiani (LB) medium and taken for test at 18 h. old stage where the colony forming units (cfus) are approximately 1-310.sup.6 per millilitre for E. coli or S. aureus. (previously standardized based on optical densities at 600 nm). 1 mL of 50% aqueous solution of base B was added to 1 mL of the bacterial broath (spiking solution) and mixed by swirling the bottle. Samples were taken for analysis after regular intervals of time. Solid powder of silica gel (60-120 mesh) was added to effect instanteneous solidification. Samples were further taken for analysis after regular intervals of time. All samples were taken as diluted 10 in sterile saline and 100 L of the diluted solution was plated onto LB agar plates andincubated over night at 37 C. Parallely, the original bacterial suspension was diluted serially in sterile saline and 100 L of the appropriate dilutions were plated on LB agar plates and incubated as for the test sample that served as controls. Colonies were counted the next day and based on applied dilution, the number of CFUs/mL of the original bacterial suspension added to the sol and the CFUs in the gelled disinfectant were calculated. Efficiency was calculated as follows:[(Number of CFUs in Bacterial suspensionNumber of CFUs in the gelled disinfectant)/Number of CFUs in Bacterial suspension]100 and expressed in %.

Example 33. Prototype for All-In-One Sample Collection-Disinfection-Disposal Devices for Fluid Samples

[0137] An all-in-one sample collection-disinfection-disposal device for fluid samples was prototyped as follows: Three plastic collection vials were mounted one on top of the other such that the top vial contained solid powder of silica gel (60-400 mesh), alumina (60-400 mesh), titamia (mixture of anatase and rutile) or zinc oxide (particle size <500 m), the middle one for sample collection and the bottom one prefilled with the requisite amount of 50% aqueous solution of sodium hydroxide. The design allows the top compartment to be unscrewed and the samples could be collected in the middle compartment. Once collected sample is tested, the remaining sample could be disinfected and solidified by initially allowing the sample to mix with the alkaline solution in the bottom container by breaking the junction between the middle and bottom compartments followed by the addition of the corresponding solid powder from the top compartment by breaking the junction between the top and middle compartments. The mixing of the three fluid mixtures allow for complete pathogenic disinfection as evidenced in Example 32.

Example 34. Prototype for All-In-One Sample Collection-Disinfection-Disposal Devices for Solid Samples

[0138] An all-in-one sample collection-disinfection-disposal device for solid samples was prototyped as follows: A plastic collection container for solid samples (Eg: cotton waste) was mounted on its top with another plastic vial such that the top vial contained silica gel (60-400 mesh), alumina (60-400 mesh), titamia (mixture of anatase and rutile) or zinc oxide (particle size <500 m), and the bottom one was prefilled with the requisite amount of 50% aqueous solution of sodium hydroxide. The design allows the top compartment to be unscrewed and the solid samples could be collected in the bottom compartment. Once ample number of solid samples are collected in the bottom container, it could be disinfected and solidified by allowing the alkaline sample to mix with the corresponding solid powders by breaking the junction between the two compartments. The mixing of the solutions and gelation allow for complete pathogenic disinfection as evidenced in Example 32.

Advantages of the Invention

[0139] Inherent antimicrobial activity [0140] Minimized amount of water required [0141] Instantaneous disinfection and solidification upon mixing [0142] >99.9% microbial disinfection within 1 minute [0143] Reduces risks of spillage and occupational exposure [0144] Allows to dispose the waste as non-regulated medical waste [0145] Applicable to both fluid as well as solid medical waste decontamination [0146] Safer, easier and cost-effective [0147] Adaptability to manage any amount of fluidic waste [0148] No interference from proteins, metal ions, salt or other impurities