Bioremediation kit and method of treating contaminated soil by using the same

Abstract

This invention relates to a bioremediation kit and a method for treating contaminated soil. The bioremediation kit comprises an enzyme solution, a conditioner, a acclimation bacterial solution, and an oil stain treatment agent. The enzyme solution contains laccase, the conditioner contains sodium bicarbonate and hydrogen peroxide, the acclimation bacterial solution contains acclimated Bacillus subtilis, and the oil stain treatment agent is obtained by aerobic fermentation of a starting material containing primary fermented biomass. Using the bioremediation kit to treat contaminated soil effectively reduces the total petroleum hydrocarbons in the contaminated soil.

Claims

1. A bioremediation kit for treating contaminated soil, wherein, based on 100% by weight of the contaminated soil, the bioremediation kit comprises: an enzyme solution containing laccase, wherein the ratio of the activity of the laccase to the weight of the contaminated soil is 10,000 U / kg to 85,000 U / kg, and the enzyme solution comprises: a concentrate, wherein the concentrate is obtained by a concentration step following a cell-free culture of Pleurotus ostreatus fruiting bodies obtained through a fermentation step and a solid-liquid separation step, the fermentation step being carried out using an induction medium at pH 4.5 to pH 6.0 at 25°C to 27°C for 1 to 3 days, followed by a fermentation step at a temperature greater than 27°C to less than 29°C for 3 to 7 days, and the induction medium comprising a carbon source, a nitrogen source, an inducer, and water, the inducer comprising 0.2 mM to 1.0 mM copper sulfate pentahydrate, 8 g / L to 11 g / L of water. The contaminated soil contains g / L lignin and 165 μL / L to 172 μL / L guaiacol; and a protective agent comprising boric acid and fructose, wherein the molar concentration ratio of boric acid to fructose is 1:(5~18), and the volume ratio of the concentrate to the protective agent is (0.5~1.5):(0.5~1.5); a modifier comprising sodium bicarbonate and hydrogen peroxide, wherein the amount of sodium bicarbonate used is 0.2% to 1.0% by weight, and the amount of hydrogen peroxide used is greater than 0.5% to 1.5% by weight; an acclimation solution comprising acclimated Bacillus subtilis, such that the contaminated soil contains 5×10⁵ CFU / g to 5×10⁸ CFU / g of the acclimated Bacillus subtilis, wherein the acclimated Bacillus subtilis is obtained by an acclimation step, the acclimation step comprising: An initial Bacillus subtilis culture is added to an acclimatization medium for inoculation, wherein the volume ratio of the initial Bacillus subtilis culture to the acclimatization medium is 10:(90~110), thereby obtaining an inoculum; the inoculum is subjected to an acclimatization treatment at 35°C to 37°C for 20 to 25 hours to obtain a subcultured Bacillus subtilis culture; and the subcultured Bacillus subtilis culture is subjected to at least one cycle of the inoculation treatment and the acclimatization treatment, wherein the acclimatization medium contains 5 g / L to 20 g / L yeast extract, 10 g / L to 25 g / L dipotassium hydrogen phosphate, 1 g / L to 5 g / L sodium chloride, and 100 mg / kg to 5000 mg / kg total petroleum hydrocarbons. Hydrocarbons (TPH) and a balanced amount of water, wherein the concentration of TPH in each of the at least one cycle of the acclimation medium is 2 to 5 times the concentration of TPH in the previous cycle; and an oil stain treatment agent, wherein the amount of the oil stain treatment agent used is 1.0 to 2% by weight.This oil stain treatment agent, at 0% by weight, is obtained by subjecting a starting material to an aerobic fermentation process at 10°C to 40°C and 60% to 70% relative humidity for 20 to 120 hours. The starting material comprises 15% to 50% by weight of primary fermented biomass, 1% to 20% by weight of a pH buffer, 1% to 15% by weight of an inorganic oxygen-releasing agent, and a balanced amount of nitrogen-phosphorus compound fertilizer.

2. The bioremediation kit as described in claim 1, wherein the carbon source comprises glucose, sucrose and / or potato dextrose culture medium.

3. The biotreatment kit as described in claim 1, wherein the nitrogen source comprises protein and / or yeast extract.

4. The biotreatment kit as claimed in claim 1, wherein the induction culture medium further comprises 2.5 g / L to 10 g / L of the dipotassium hydrogen phosphate and / or 1 g / L to 2 g / L of manganese sulfate monohydrate.

5. The bioremediation kit as described in claim 1, wherein the Bacillus subtilis is Bacillus subtilis Y1336.

6. The biotreatment kit as claimed in claim 1, wherein the TPH is a mixed oil emulsion obtained by emulsifying and filtering an oil mixture, and the oil mixture contains diesel and engine oil in a volume ratio of (0.5~1.5):(0.5~1.5).

7. A method for treating contaminated soil using a bioremediation kit, comprising applying the bioremediation kit as described in any one of claims 1 to 6 to a contaminated soil and performing a remediation step at 20°C to 40°C.

8. A method for treating contaminated soil using the bioremediation kit as described in claim 7, wherein when the contaminated soil contains more than 1,000 mg / kg to 8,000 mg / kg of TPH, the remediation step is carried out for more than 3 to 14 days.

9. A method for treating contaminated soil using the bioremediation kit as described in claim 7, wherein when the contaminated soil contains more than 8,000 mg / kg to less than 13,000 mg / kg of TPH, the remediation step is carried out for more than 14 to 20 days.

10. A method for treating contaminated soil using the bioremediation kit as described in claim 7, wherein the salt content of the contaminated soil is less than or equal to 30‰.

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