An environmentally friendly process for enhanced reduction of nitrogen in ditch and pond sludge in agricultural areas

Abstract

The present invention relates to the technical field of ditch and pond sediments, and specifically to an environmentally friendly process method for enhanced nitrogen reduction in ditch and pond sediments in agricultural areas, comprising the following steps: adding 45 to 50 parts by weight of an auxiliary adjustment liquid modified by doped layered mica powder to the ditch and pond sediments in agricultural areas, stirring and improving the treatment, and completing the stirring to obtain an improved sediment body. In the process for enhanced nitrogen reduction in ditch and pond sediments of the present invention, the auxiliary adjustment liquid modified by doped layered mica powder is stirred and improved, and then stirred and adjusted with a microbial agent loaded with biochar, and the coordination between the raw materials is improved to improve the coordination of ammonia nitrogen, organic COD removal rate and heavy metal passivation rate. At the same time, the process has a significant removal rate stability effect under a low-temperature, high-temperature and acid environment.

Description

Technical Field

[0001] The invention relates to the technical field of ditch and pond sludge, and in particular to an environmentally friendly process for enhanced reduction of nitrogen in ditch and pond sludge in agricultural areas. Background Art

[0002] The environmental protection technology for ditch and pond mud in agricultural areas is to identify and screen out denitrification functional microorganisms, adopt microbial compound immobilization technology, achieve local enrichment of microorganisms and pollutants in functional materials, achieve nitrogen removal effect through efficient degradation and synergistic efficiency, and build a low-carbon and high-efficiency denitrification system for ditch and pond mud in intensive agricultural areas during the dry season.

[0003] The existing ditch and pond sludge uses microbial anaerobic ammonia oxidation to remove ammonia nitrogen. The process is relatively simple and has poor ammonia nitrogen removal efficiency. At the same time, the process is difficult to achieve the coordinated removal effect of ammonia nitrogen and organic COD in the sludge and the passivation of heavy metals. The microorganisms in the process have poor low-temperature and heat resistance and acid stability. In a low-temperature and high-temperature and acid environment, the ammonia nitrogen and organic COD removal rate in the sludge and the stability of heavy metal passivation are poor, which limits the use efficiency of the process. Based on this, the present invention further improves it. Summary of the invention

[0004] In view of the defects of the prior art, the purpose of the present invention is to provide an environmentally friendly process for enhanced reduction of nitrogen in ditch and pond mud in agricultural areas, so as to solve the problems raised in the above-mentioned background technology.

[0005] The present invention solves the technical problem by adopting the following technical solution:

[0006] The present invention provides an environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas, comprising the following steps:

[0007] Step 1: adding 45 to 50 parts by weight of an auxiliary liquid modified by doping layered mica powder to the bottom mud of the ditch and pond in the agricultural area, stirring and improving the treatment, and after the stirring is completed, obtaining a treated and improved bottom mud body;

[0008] Step 2: Add 30 to 35 parts by weight of the biochar-loaded microbial agent to the treated and improved sediment body and continue to mix and fully treat it. After the mixing is completed, the sediment nitrogen enhanced reduction step can be completed;

[0009] The preparation method of the auxiliary adjustment liquid modified by doping layered mica powder is as follows:

[0010] S01, stirring and mixing the layered nano mica powder in a sufficient amount of a 2% by mass sulfuric acid solution, then washing, filtering, and drying, and subjecting the dried layered nano mica powder to thermal improvement treatment to obtain a thermally regulated layered nano mica powder;

[0011] The specific thermal improvement treatment method is:

[0012] First, heat up to 255-275°C at a rate of 2-5°C / min, keep warm for 5-10 minutes, then heat up to 350°C at a rate of 1-3°C / min, keep warm for 35-45 minutes, and finally air cool to room temperature;

[0013] S02, the heat-regulated layered nano mica powder and the modified liquid doped with alumina are modified and stirred at a ratio of 3:5, and after the stirring is completed, the modified layered nano mica powder is filtered and dried to obtain a modified layered nano mica powder;

[0014] S03, adding nano titanium dioxide to a sodium lignin sulfonate solution having a volume of 3 to 5 times the total volume of nano titanium dioxide and stirring thoroughly to obtain a nano titanium dioxide agent;

[0015] S04, 5 to 8 parts of modified layered nano mica powder, 3 to 6 parts of nano titanium dioxide agent and 10 to 15 parts of sodium alginate solution are uniformly blended, and then 2 to 3 parts of sodium carboxymethyl cellulose are added and continued to blend to obtain a modified auxiliary liquid doped with layered mica powder.

[0016] Preferably, the stirring speed of the stirring improvement treatment is 550-600 r / min, and the stirring time is 1-2 h.

[0017] Preferably, the mass fraction of the sodium alginate solution is 4-7%; the mass fraction of the sodium lignin sulfonate solution is 4-6%.

[0018] Preferably, the stirring speed of the modified stirring treatment in S02 is 550 to 750 r / min, and the stirring is performed for 20 to 30 minutes.

[0019] Preferably, the modified solution for adjusting the performance of the doped alumina comprises the following raw materials in parts by weight:

[0020] 3 to 5 parts of nano-alumina, 1 to 3 parts of stearic acid, 2 to 5 parts of cordierite powder, 5 to 8 parts of zinc sulfate solution and 2 to 4 parts of sodium dodecylbenzene sulfonate.

[0021] Preferably, the mass fraction of the zinc sulfate solution is 3-5%.

[0022] Preferably, the preparation method of the biochar-loaded microbial agent is:

[0023] S11, preparation of melamine body:

[0024] Melamine and paraformaldehyde were mixed in a weight ratio of 1:3, and then distilled water and sodium hydroxide in an amount of 5 times the total amount of melamine were added, and the pH was adjusted to 7.5. The mixture was heated to 78°C under stirring and reacted for 30 minutes. Then, terephthalaldehyde, a modifier in an amount of 10% of the total amount of melamine, was added, and the temperature was maintained and stirred for 1 hour, and the mixture was set aside to obtain a melamine body.

[0025] S12, preparation of immersion solution:

[0026] S121, preparing additives:

[0027] 2-3 parts of hydroxyapatite and 4-6 parts of nano-silicon carbide whiskers are added to 5-8 parts of chitosan solution with a mass fraction of 4%, and then 1-2 parts of nano-silica sol are added to mix and ball-milled thoroughly at a ball-milling speed of 1500r / min for 2h. After the ball-milling is completed, the additive is filtered and dried to obtain the additive;

[0028] S122, adding 5 to 8 parts of the additive to 6 to 10 parts of a 5% by mass sodium silicate solution, and then adding 2 to 3 parts of a silane coupling agent KH550 to fully blend to obtain an impregnation solution;

[0029] S13, the biochar is immersed in an immersion liquid of 3 to 5 times the total amount of the biochar, and the immersion is completed to obtain an immersed biochar agent;

[0030] S14, stirring the melamine body, the impregnated biochar agent and the microbial agent in a weight ratio of 2: (5-7): (3-4), filtering and drying after the stirring is completed, and obtaining the biochar-loaded microbial agent.

[0031] Preferably, the immersion ultrasonic power of the immersion treatment in S13 is 500-550W, and the immersion time is 30-40min; the stirring speed of the stirring treatment in S14 is 350-400r / min, and the stirring time is 25-35min.

[0032] Preferably, the microbial agent is a bacterial solution of Bacillus subtilis, nitrite bacteria, and Rhodopseudomonas palustris, which are cultured separately to a bacterial concentration OD600 of 3, and then mixed in a ratio of 2:2:1 and made into a freeze-dried powder.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. In the process for enhancing nitrogen reduction in ditch and pond sludge of the present invention, the stirring of the auxiliary liquid modified by doping layered mica powder is improved, and then the microbial agent loaded with biochar is stirred and blended. Through the coordination between the raw materials, the coordination of ammonia nitrogen, organic COD removal rate and heavy metal passivation rate is improved. At the same time, the process has a significant removal rate stability effect under a low-temperature-high-temperature and acid environment;

[0035] 2. The biochar-loaded microbial agent is made of melamine, polyformaldehyde and other raw materials to form a melamine body. The melamine body has multiple active groups, so that the impregnated biochar agent and the microbial agent can be better matched into the system, and the ammonia nitrogen and organic COD removal rate of the system and the passivation effect of heavy metals can be enhanced. The impregnated biochar agent is improved by the biochar through the impregnation liquid. The hydroxyapatite and nano silicon carbide whiskers in the impregnation liquid are used as the matrix materials, which are matched with each other. The whisker-like whisker structure is matched with the point-shaped hydroxyapatite to coordinate the biochar and better carry the biological agent, so that the performance effect of the product is more significantly improved. At the same time, the additives, sodium silicate solution and silane coupling agent KH550 in the impregnation liquid are blended, so as to better match the impregnated biochar agent with the melamine body and the microbial agent, so that the obtained biochar-loaded microbial agent optimizes the ammonia nitrogen and organic COD removal rate and the passivation rate of heavy metals in the process in the system;

[0036] 3. The auxiliary liquid modified by doping layered mica powder is treated with an acid solution through layered nano mica powder, and then combined with a heat improvement treatment. In the heat improvement treatment, the temperature is raised to 255-275°C at a rate of 2-5°C / min, and the temperature is kept for 5-10 minutes, and then the temperature is raised to 350°C at a rate of 1-3°C / min, and the temperature is kept for 35-45 minutes. Finally, it is air-cooled to room temperature. The step-by-step heat improvement is adopted to optimize the activity efficiency of the nano mica powder and improve the interlayer structure of the mica powder. On the one hand, it plays a role in the adsorption of ammonia nitrogen, heavy metals and organic COD, and at the same time, it is interspersed in the system to enhance the performance stability of the system. At the same time, it is further improved by the modified liquid doped with alumina.

[0037] 4. The modified liquid doped with alumina is blended with nano alumina, stearic acid, cordierite powder, zinc sulfate solution and sodium dodecylbenzene sulfonate. The synergistic effect of the modified liquid doped with alumina and layered nano mica powder is enhanced by combining nano alumina with cordierite powder and zinc sulfate solution as raw materials, so that the removal rate performance stability of the product system is more excellent, and the coordination of ammonia nitrogen, heavy metals and organic COD removal rates is enhanced; at the same time, the added nano titanium dioxide is treated with sodium lignin sulfonate solution and blended with sodium alginate solution and sodium carboxymethyl cellulose to obtain an auxiliary liquid modified with layered mica powder, which enhances the effect of the microbial agent loaded by biochar in the system on ammonia nitrogen, heavy metals and organic COD, thereby optimizing the removal rate and the removal rate stability. DETAILED DESCRIPTION

[0038] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas of this embodiment comprises the following steps:

[0040] Step 1: adding 45 to 50 parts by weight of an auxiliary liquid modified by doping layered mica powder to the bottom mud of the ditch and pond in the agricultural area, stirring and improving the treatment, and after the stirring is completed, obtaining a treated and improved bottom mud body;

[0041] Step 2: Add 30 to 35 parts by weight of biochar-loaded microbial agent to the treated and improved sediment body and continue to mix and treat thoroughly. When the mixing is completed, the sediment nitrogen enhanced reduction step is completed.

[0042] The stirring speed of the stirring improvement treatment in this embodiment is 550-600 r / min, and the stirring time is 1-2 h.

[0043] The preparation method of the auxiliary adjustment liquid modified by doping layered mica powder in this embodiment is:

[0044] S01, stirring and mixing the layered nano mica powder in a sufficient amount of a 2% by mass sulfuric acid solution, then washing, filtering, and drying, and subjecting the dried layered nano mica powder to thermal improvement treatment to obtain a thermally regulated layered nano mica powder;

[0045] The specific thermal improvement treatment method is:

[0046] First, heat up to 255-275°C at a rate of 2-5°C / min, keep warm for 5-10 minutes, then heat up to 350°C at a rate of 1-3°C / min, keep warm for 35-45 minutes, and finally air cool to room temperature;

[0047] S02, the heat-regulated layered nano mica powder and the modified liquid doped with alumina are modified and stirred at a ratio of 3:5, and after the stirring is completed, the modified layered nano mica powder is filtered and dried to obtain a modified layered nano mica powder;

[0048] S03, adding nano titanium dioxide to a sodium lignin sulfonate solution having a volume of 3 to 5 times the total volume of nano titanium dioxide and stirring thoroughly to obtain a nano titanium dioxide agent;

[0049] S04, 5 to 8 parts of modified layered nano mica powder, 3 to 6 parts of nano titanium dioxide agent and 10 to 15 parts of sodium alginate solution are uniformly blended, and then 2 to 3 parts of sodium carboxymethyl cellulose are added and continued to blend to obtain a modified auxiliary liquid doped with layered mica powder.

[0050] The mass fraction of the sodium alginate solution in this embodiment is 4-7%; the mass fraction of the sodium lignin sulfonate solution is 4-6%.

[0051] The stirring speed of the modified stirring treatment in S02 of this embodiment is 550 to 750 r / min, and the stirring time is 20 to 30 minutes.

[0052] The modified solution for adjusting the performance of doped alumina in this embodiment includes the following raw materials in parts by weight:

[0053] 3 to 5 parts of nano-alumina, 1 to 3 parts of stearic acid, 2 to 5 parts of cordierite powder, 5 to 8 parts of zinc sulfate solution and 2 to 4 parts of sodium dodecylbenzene sulfonate.

[0054] The mass fraction of the zinc sulfate solution in this embodiment is 3-5%.

[0055] The preparation method of the biochar-loaded microbial agent of this embodiment is:

[0056] S11, preparation of melamine body:

[0057] Melamine and paraformaldehyde were mixed in a weight ratio of 1:3, and then distilled water and sodium hydroxide in an amount of 5 times the total amount of melamine were added, and the pH was adjusted to 7.5. The mixture was heated to 78°C under stirring and reacted for 30 minutes. Then, terephthalaldehyde, a modifier in an amount of 10% of the total amount of melamine, was added, and the temperature was maintained and stirred for 1 hour, and the mixture was set aside to obtain a melamine body.

[0058] S12, preparation of immersion solution:

[0059] S121, preparing additives:

[0060] 2-3 parts of hydroxyapatite and 4-6 parts of nano-silicon carbide whiskers are added to 5-8 parts of chitosan solution with a mass fraction of 4%, and then 1-2 parts of nano-silica sol are added to mix and ball-milled thoroughly at a ball-milling speed of 1500r / min for 2h. After the ball-milling is completed, the additive is filtered and dried to obtain the additive;

[0061] S122, adding 5 to 8 parts of the additive to 6 to 10 parts of a 5% by mass sodium silicate solution, and then adding 2 to 3 parts of a silane coupling agent KH550 to fully blend to obtain an impregnation solution;

[0062] S13, the biochar is immersed in an immersion liquid of 3 to 5 times the total amount of the biochar, and the immersion is completed to obtain an immersed biochar agent;

[0063] S14, stirring the melamine body, the impregnated biochar agent and the microbial agent in a weight ratio of 2: (5-7): (3-4), filtering and drying after the stirring is completed, and obtaining the biochar-loaded microbial agent.

[0064] The immersion ultrasonic power of the immersion treatment in S13 of this embodiment is 500-550W, and the immersion time is 30-40min; the stirring speed of the stirring treatment in S14 is 350-400r / min, and the stirring time is 25-35min.

[0065] The microbial agent of this embodiment is a bacterial solution of Bacillus subtilis, nitrite bacteria, and Rhodopseudomonas palustris, which are cultured separately to a bacterial concentration OD600 of 3, and then mixed in a ratio of 2:2:1 and made into a freeze-dried powder.

[0066] Example 1

[0067] The environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas of this embodiment comprises the following steps:

[0068] Step 1: adding 45 to 50 parts by weight of an auxiliary liquid modified by doping layered mica powder to the bottom mud of the ditch and pond in the agricultural area, stirring and improving the treatment, and after the stirring is completed, obtaining a treated and improved bottom mud body;

[0069] Step 2: Add 30 to 35 parts by weight of biochar-loaded microbial agent to the treated and improved sediment body and continue to mix and treat thoroughly. When the mixing is completed, the sediment nitrogen enhanced reduction step is completed.

[0070] The stirring speed of the stirring improvement treatment in this embodiment is 550 r / min and the stirring time is 1 h.

[0071] The preparation method of the auxiliary adjustment liquid modified by doping layered mica powder in this embodiment is:

[0072] S01, stirring and mixing the layered nano mica powder in a sufficient amount of a 2% by mass sulfuric acid solution, then washing, filtering, and drying, and subjecting the dried layered nano mica powder to thermal improvement treatment to obtain a thermally regulated layered nano mica powder;

[0073] The specific thermal improvement treatment method is:

[0074] First, heat to 255°C at a rate of 2°C / min, keep warm for 5 minutes, then heat to 350°C at a rate of 1°C / min, keep warm for 35 minutes, and finally air cool to room temperature;

[0075] S02, the heat-regulated layered nano mica powder and the modified liquid doped with alumina are modified and stirred at a ratio of 3:5, and after the stirring is completed, the modified layered nano mica powder is filtered and dried to obtain a modified layered nano mica powder;

[0076] S03, adding nano titanium dioxide to a sodium lignin sulfonate solution having a volume 3 times the total volume of nano titanium dioxide and stirring thoroughly to obtain a nano titanium dioxide agent;

[0077] S04, 5 parts of modified layered nano mica powder, 3 parts of nano titanium dioxide agent and 10 parts of sodium alginate solution are evenly blended, and then 2 parts of sodium carboxymethyl cellulose are added and continued to blend to obtain a modified auxiliary solution doped with layered mica powder.

[0078] The mass fraction of the sodium alginate solution in this embodiment is 4%; the mass fraction of the sodium lignin sulfonate solution is 4%.

[0079] The stirring speed of the modified stirring treatment in S02 of this embodiment is 550 r / min, and the stirring is performed for 20 min.

[0080] The modified solution for adjusting the performance of doped alumina in this embodiment includes the following raw materials in parts by weight:

[0081] 3 parts of nano-alumina, 1 part of stearic acid, 2 parts of cordierite powder, 5 parts of zinc sulfate solution and 2 parts of sodium dodecylbenzene sulfonate.

[0082] The mass fraction of the zinc sulfate solution in this embodiment is 3%.

[0083] The preparation method of the biochar-loaded microbial agent of this embodiment is:

[0084] S11, preparation of melamine body:

[0085] Melamine and paraformaldehyde were mixed in a weight ratio of 1:3, and then distilled water and sodium hydroxide in an amount of 5 times the total amount of melamine were added, and the pH was adjusted to 7.5. The mixture was heated to 78°C under stirring and reacted for 30 minutes. Then, terephthalaldehyde, a modifier in an amount of 10% of the total amount of melamine, was added, and the temperature was maintained and stirred for 1 hour, and the mixture was set aside to obtain a melamine body.

[0086] S12, preparation of immersion solution:

[0087] S121, preparing additives:

[0088] 2 parts of hydroxyapatite and 4 parts of nano silicon carbide whiskers were added to 5 parts of chitosan solution with a mass fraction of 4%, and then 1 part of nano silica sol was added to blend and ball milled thoroughly at a ball milling speed of 1500 r / min for 2 hours. After the ball milling was completed, the additive was filtered and dried to obtain the additive;

[0089] S122, adding 5 parts of the additive to 6 parts of 5% by mass sodium silicate solution, and then adding 2 parts of silane coupling agent KH550 to fully blend to obtain an impregnation solution;

[0090] S13, the biochar is immersed in an immersion liquid of 3 times the total amount of the biochar, and the immersion is completed to obtain an immersed biochar agent;

[0091] S14, stirring the melamine body, the impregnated biochar agent and the microbial agent in a weight ratio of 2:5:3, filtering and drying after the stirring is completed, to obtain the biochar-loaded microbial agent.

[0092] The immersion ultrasonic power of the immersion treatment in S13 of this embodiment is 500W, and the immersion time is 30min; the stirring speed of the stirring treatment in S14 is 350r / min, and the stirring time is 25min.

[0093] The microbial agent of this embodiment is a bacterial solution of Bacillus subtilis, nitrite bacteria, and Rhodopseudomonas palustris, which are cultured separately to a bacterial concentration OD600 of 3, and then mixed in a ratio of 2:2:1 and made into a freeze-dried powder.

[0094] Example 2

[0095] The environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas of this embodiment comprises the following steps:

[0096] Step 1: adding 45 to 50 parts by weight of an auxiliary liquid modified by doping layered mica powder to the bottom mud of the ditch and pond in the agricultural area, stirring and improving the treatment, and after the stirring is completed, obtaining a treated and improved bottom mud body;

[0097] Step 2: Add 30 to 35 parts by weight of biochar-loaded microbial agent to the treated and improved sediment body and continue to mix and treat thoroughly. When the mixing is completed, the sediment nitrogen enhanced reduction step is completed.

[0098] The stirring speed of the stirring improvement treatment described in this embodiment is 600r / min, and the stirring time is 2h.

[0099] The preparation method of the auxiliary adjustment liquid modified by doping layered mica powder in this embodiment is:

[0100] S01, stirring and mixing the layered nano mica powder in a sufficient amount of a 2% by mass sulfuric acid solution, then washing, filtering, and drying, and subjecting the dried layered nano mica powder to thermal improvement treatment to obtain a thermally regulated layered nano mica powder;

[0101] The specific thermal improvement treatment method is:

[0102] First, heat to 275℃ at a rate of 5℃ / min, keep warm for 10min, then heat to 350℃ at a rate of 3℃ / min, keep warm for 45min, and finally air cool to room temperature;

[0103] S02, the heat-regulated layered nano mica powder and the modified liquid doped with alumina are modified and stirred at a ratio of 3:5, and after the stirring is completed, the modified layered nano mica powder is filtered and dried to obtain a modified layered nano mica powder;

[0104] S03, adding nano titanium dioxide to a sodium lignin sulfonate solution having a volume 5 times the total volume of nano titanium dioxide and stirring thoroughly to obtain a nano titanium dioxide agent;

[0105] S04, 8 parts of modified layered nano mica powder, 6 parts of nano titanium dioxide agent and 15 parts of sodium alginate solution are evenly blended, and then 3 parts of sodium carboxymethyl cellulose are added and continued to blend to obtain a modified auxiliary solution doped with layered mica powder.

[0106] The mass fraction of the sodium alginate solution in this embodiment is 7%; the mass fraction of the sodium lignin sulfonate solution is 6%.

[0107] The stirring speed of the modified stirring treatment in S02 of this embodiment is 750 r / min, and the stirring is for 30 min.

[0108] The modified solution for adjusting the performance of doped alumina in this embodiment includes the following raw materials in parts by weight:

[0109] 5 parts of nano-alumina, 3 parts of stearic acid, 5 parts of cordierite powder, 8 parts of zinc sulfate solution and 4 parts of sodium dodecylbenzene sulfonate.

[0110] The mass fraction of the zinc sulfate solution in this embodiment is 5%.

[0111] The preparation method of the biochar-loaded microbial agent of this embodiment is:

[0112] S11, preparation of melamine body:

[0113] Melamine and paraformaldehyde were mixed in a weight ratio of 1:3, and then distilled water and sodium hydroxide in an amount of 5 times the total amount of melamine were added, and the pH was adjusted to 7.5. The mixture was heated to 78°C under stirring and reacted for 30 minutes. Then, terephthalaldehyde, a modifier in an amount of 10% of the total amount of melamine, was added, and the temperature was maintained and stirred for 1 hour, and the mixture was set aside to obtain a melamine body.

[0114] S12, preparation of immersion solution:

[0115] S121, preparing additives:

[0116] 3 parts of hydroxyapatite and 6 parts of nano silicon carbide whiskers were added to 8 parts of chitosan solution with a mass fraction of 4%, and then 2 parts of nano silica sol were added to blend and ball milled thoroughly at a ball milling speed of 1500 r / min for 2 hours. After the ball milling was completed, the additive was filtered and dried to obtain the additive;

[0117] S122, adding 8 parts of the additive to 10 parts of a 5% by mass sodium silicate solution, and then adding 3 parts of a silane coupling agent KH550 to fully blend to obtain an impregnation solution;

[0118] S13, the biochar is immersed in an immersion liquid of 5 times the total amount of the biochar, and the immersion is completed to obtain an immersed biochar agent;

[0119] S14, stirring the melamine body, the impregnated biochar agent and the microbial agent in a weight ratio of 2:7:4, filtering and drying after the stirring is completed, to obtain the biochar-loaded microbial agent.

[0120] The immersion ultrasonic power of the immersion treatment in S13 of this embodiment is 550W, and the immersion time is 40min; the stirring speed of the stirring treatment in S14 is 400r / min, and the stirring time is 35min.

[0121] The microbial agent of this embodiment is a bacterial solution of Bacillus subtilis, nitrite bacteria, and Rhodopseudomonas palustris, which are cultured separately to a bacterial concentration OD600 of 3, and then mixed in a ratio of 2:2:1 and made into a freeze-dried powder.

[0122] Example 3

[0123] The environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas of this embodiment comprises the following steps:

[0124] Step 1: adding 45 to 50 parts by weight of an auxiliary liquid modified by doping layered mica powder to the bottom mud of the ditch and pond in the agricultural area, stirring and improving the treatment, and after the stirring is completed, obtaining a treated and improved bottom mud body;

[0125] Step 2: Add 30 to 35 parts by weight of biochar-loaded microbial agent to the treated and improved sediment body and continue to mix and treat thoroughly. When the mixing is completed, the sediment nitrogen enhanced reduction step is completed.

[0126] The stirring speed of the stirring improvement treatment in this embodiment is 570r / min, and the stirring time is 1.5h.

[0127] The preparation method of the auxiliary adjustment liquid modified by doping layered mica powder in this embodiment is:

[0128] S01, stirring and mixing the layered nano mica powder in a sufficient amount of a 2% by mass sulfuric acid solution, then washing, filtering, and drying, and subjecting the dried layered nano mica powder to thermal improvement treatment to obtain a thermally regulated layered nano mica powder;

[0129] The specific thermal improvement treatment method is:

[0130] First, heat to 260℃ at a rate of 3.5℃ / min, keep at that temperature for 7.5min, then heat to 350℃ at a rate of 2℃ / min, keep at that temperature for 40min, and finally air cool to room temperature;

[0131] S02, the heat-regulated layered nano mica powder and the modified liquid doped with alumina are modified and stirred at a ratio of 3:5, and after the stirring is completed, the modified layered nano mica powder is filtered and dried to obtain a modified layered nano mica powder;

[0132] S03, adding nano titanium dioxide to a sodium lignin sulfonate solution with a volume 4 times the total volume of nano titanium dioxide and stirring thoroughly to obtain a nano titanium dioxide agent;

[0133] S04, 6.5 parts of modified layered nano mica powder, 4.5 parts of nano titanium dioxide agent and 12.5 parts of sodium alginate solution are evenly blended, and then 2.5 parts of sodium carboxymethyl cellulose are added and continued to blend to obtain a modified auxiliary solution doped with layered mica powder.

[0134] The mass fraction of the sodium alginate solution in this embodiment is 5.5%; the mass fraction of the sodium lignin sulfonate solution is 5%.

[0135] The stirring speed of the modified stirring treatment in S02 of this embodiment is 600 r / min, and the stirring is performed for 25 min.

[0136] The modified solution for adjusting the performance of doped alumina in this embodiment includes the following raw materials in parts by weight:

[0137] 4 parts of nano-alumina, 2 parts of stearic acid, 3.5 parts of cordierite powder, 6.5 parts of zinc sulfate solution and 3 parts of sodium dodecylbenzene sulfonate.

[0138] The mass fraction of the zinc sulfate solution in this embodiment is 4%.

[0139] The preparation method of the biochar-loaded microbial agent of this embodiment is:

[0140] S11, preparation of melamine body:

[0141] Melamine and paraformaldehyde were mixed in a weight ratio of 1:3, and then distilled water and sodium hydroxide in an amount of 5 times the total amount of melamine were added, and the pH was adjusted to 7.5. The mixture was heated to 78°C under stirring and reacted for 30 minutes. Then, terephthalaldehyde, a modifier in an amount of 10% of the total amount of melamine, was added, and the temperature was maintained and stirred for 1 hour, and the mixture was set aside to obtain a melamine body.

[0142] S12, preparation of immersion solution:

[0143] S121, preparing additives:

[0144] 2.5 parts of hydroxyapatite and 5 parts of nano-silicon carbide whiskers were added to 6.5 parts of chitosan solution with a mass fraction of 4%, and then 1.5 parts of nano-silica sol were added to blend and ball-milled thoroughly at a ball-milling speed of 1500 r / min for 2 hours. After the ball-milling was completed, the mixture was filtered and dried to obtain an additive;

[0145] S122, adding 6.5 parts of the additive to 8 parts of 5% by mass sodium silicate solution, and then adding 2.5 parts of silane coupling agent KH550 to fully blend to obtain an impregnation solution;

[0146] S13, the biochar is immersed in an immersion liquid of 4 times the total amount of the biochar, and the immersion is completed to obtain an immersed biochar agent;

[0147] S14, stirring the melamine body, the impregnated biochar agent and the microbial agent in a weight ratio of 2:6:3.5, filtering and drying after the stirring is completed, to obtain the biochar-loaded microbial agent.

[0148] The immersion ultrasonic power of the immersion treatment in S13 of this embodiment is 55W, and the immersion time is 35min; the stirring speed of the stirring treatment in S14 is 375r / min, and the stirring time is 30min.

[0149] The microbial agent of this embodiment is a bacterial solution of Bacillus subtilis, nitrite bacteria, and Rhodopseudomonas palustris, which are cultured separately to a bacterial concentration OD600 of 3, and then mixed in a ratio of 2:2:1 and made into a freeze-dried powder.

[0150] Comparative Example 1

[0151] The difference from Example 3 is that the stirring improvement treatment in the auxiliary adjustment liquid modified by doping layered mica powder is not adopted.

[0152] Comparative Example 2

[0153] The difference from Example 3 is that no nano titanium dioxide agent is added to the auxiliary adjustment liquid modified by doping layered mica powder.

[0154] Comparative Example 3

[0155] The difference from Example 3 is that the modified layered nano mica powder is not added into the auxiliary adjustment liquid modified by doping layered mica powder.

[0156] Comparative Example 4

[0157] The difference from Example 3 is that the S01 step is not used in the preparation of the modified layered nano mica powder.

[0158] Comparative Example 5

[0159] The difference from Example 3 is that the modified layered nano-mica powder is not treated with a modified liquid for adjusting the performance by doping with alumina.

[0160] Comparative Example 6

[0161] The difference from Example 3 is that the biochar-loaded microbial agent is directly replaced by the microbial agent of the present invention.

[0162] Comparative Example 7

[0163] The difference from Example 3 is that no melamine was added in the preparation of the biochar-loaded microbial agent.

[0164] Comparative Example 8

[0165] The difference from Example 3 is that no impregnated biochar agent is added in the preparation of the biochar-loaded microbial agent.

[0166] Comparative Example 9

[0167] The difference from Example 3 is that no additives were added during the preparation of the impregnated biochar agent.

[0168] Comparative Example 10

[0169] The difference from Example 3 is that the preparation method of the additive is different: no hydroxyapatite is added.

[0170] Comparative Example 11

[0171] The difference from Example 3 is that the preparation method of the additive is different: no silicon carbide whiskers are added.

[0172] Comparative Example 12

[0173] The difference from Example 3 is that the silane coupling agent KH550 is not added to the impregnation solution and the sodium silicate solution is replaced by water.

[0174] The conventional performance tests of the products of Examples 1 to 3 and Comparative Examples 1 to 12 are performed, and the performance measurement results are shown in Table 1 below. Table 1 is a performance test table of COD removal rate, passivation rate of heavy metal Cd and ammonia nitrogen removal rate under conventional conditions:

[0175] Table 1

[0176]

[0177] Based on the above test, the present invention places the test environment in 2% hydrochloric acid mist and a low temperature environment of 5°C for testing, and the low temperature resistance and acid mist stability of the test process are tested, and the test environment is placed in 2% hydrochloric acid mist and a high temperature environment of 60°C for testing, and the high temperature resistance and acid mist stability of the test process are tested. The test results are shown in Table 2 below, which is a performance test table of COD removal rate, passivation rate of heavy metal Cd and removal rate of ammonia nitrogen under low temperature resistance, acid mist resistance and high temperature resistance and acid mist resistance conditions:

[0178] Table 2

[0179]

[0180] From Examples 1 to 3 and Comparative Examples 1 to 12, as well as high temperature resistance, low temperature resistance, and acid mist resistance, it can be seen that the COD removal rate, the passivation rate of heavy metal Cd, and the ammonia nitrogen removal rate of Example 3 of the present invention are coordinated, and the product process has high temperature resistance, low temperature resistance, and acid mist resistance stability;

[0181] The present invention does not use the stirring improvement treatment in the auxiliary adjustment liquid modified by doping layered mica powder and the microbial agent loaded with biochar to directly replace the microbial agent of the present invention, and the performance of the product has a significant trend of deterioration. The stirring improvement treatment in the auxiliary adjustment liquid modified by doping layered mica powder and the microbial agent loaded with biochar are coordinated and work together, and the product performance effect is most significant;

[0182] The performance of the products showed a trend of deterioration to varying degrees when the auxiliary adjustment liquid modified by doping layered mica powder was not treated with nano-titanium dioxide agent, the auxiliary adjustment liquid modified by doping layered mica powder was not treated with modified layered nano-mica powder, the S01 step was not used in the preparation of the modified layered nano-mica powder, and the modified liquid for adjusting the performance by doping alumina was not used in the preparation of the modified layered nano-mica powder. At the same time, the performance of the products deteriorated significantly when the modified liquid for adjusting the performance by doping alumina was not used. The auxiliary adjustment liquid modified by doping layered mica powder obtained by the specific method of the present invention and the modified layered nano-mica powder were used in combination with the specific process, and the product performance effect was the most significant.

[0183] No melamine was added in the preparation of the biochar-loaded microbial agent, no impregnated biochar was added in the preparation of the biochar-loaded microbial agent, no additive was added in the preparation of the impregnated biochar agent, the preparation methods of the additives were different: no hydroxyapatite was added, the preparation methods of the additives were different: no silicon carbide whiskers were added, no silane coupling agent KH550 was added to the impregnation solution, and the sodium silicate solution was replaced by water. The performance of the products all tended to deteriorate. The additives, impregnated biochar agents and melamine bodies obtained by the method of the present invention obtained a specific biochar-loaded microbial agent, and the product performance effect was the most significant. The effects of other methods were not as obvious as those of the present invention.

[0184] The modified liquid based on doped alumina has a significant impact on the performance of the product, and further research on this is as follows:

[0185] The modified solution for adjusting the performance by doping with alumina comprises the following raw materials in parts by weight:

[0186] 4 parts of nano-alumina, 2 parts of stearic acid, 3.5 parts of cordierite powder, 6.5 parts of zinc sulfate solution and 3 parts of sodium dodecylbenzene sulfonate.

[0187] The mass fraction of the zinc sulfate solution in this embodiment is 4%.

[0188] Experimental Example 1

[0189] The only difference from Example 3 is that no nano-alumina is added to the modified solution for adjusting the performance by doping alumina.

[0190] Experimental Example 2

[0191] The only difference from Example 3 is that no cordierite powder is added to the modified solution doped with alumina for performance adjustment.

[0192] Experimental Example 3

[0193] The only difference from Example 3 is that the zinc sulfate solution in the modified solution for adjusting the performance by doping with alumina is replaced by water.

[0194] Experimental Example 4

[0195] The only difference from Example 3 is that stearic acid and sodium dodecylbenzene sulfonate are not added to the modified solution for adjusting the performance by doping with alumina.

[0196] Experimental Example 5

[0197] The only difference from Example 3 is that the mass fraction of zinc sulfate solution is 6%.

[0198] Based on the low-temperature-high-temperature resistance and acid mist resistance tests, the performance of Experimental Examples 1-5 was tested, and the tests were as shown in Table 3. Table 3 is a test table of the effect of the modified liquid doped with alumina on the performance of the product:

[0199] Table 3

[0200]

[0201] It can be seen from Experimental Examples 1-5 that cordierite powder is not added to the modified liquid for adjustment by doping alumina, and the performance stability of the product deteriorates significantly. At the same time, nano alumina is not added to the modified liquid for adjustment by doping alumina, and the zinc sulfate solution in the modified liquid for adjustment by doping alumina is replaced by water, and the performance of the product has a tendency to deteriorate. In addition, stearic acid and sodium dodecylbenzene sulfonate are not added to the modified liquid for adjustment by doping alumina, and the mass fraction of zinc sulfate solution is 6%, and the performance of the product also shows a tendency to deteriorate. Only the modified liquid for adjustment by doping alumina prepared by using the specific raw materials of the present invention has the most significant performance effect of the product. The effects of other methods are not as obvious as those of the present invention. In addition, the mass fraction of zinc sulfate solution is specific and is not within the range of the present invention, and the product performance also shows a tendency to deteriorate.

[0202] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0203] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas, characterized in that: The following steps are involved: Step 1: adding 45 to 50 parts by weight of an auxiliary liquid modified by doping layered mica powder to the bottom mud of the ditch and pond in the agricultural area, stirring and improving the treatment, and after the stirring is completed, obtaining a treated and improved bottom mud body; Step 2: Add 30 to 35 parts by weight of the biochar-loaded microbial agent to the treated and improved sediment body and continue to mix and fully treat it. After the mixing is completed, the sediment nitrogen enhanced reduction step can be completed; The preparation method of the auxiliary adjustment liquid modified by doping layered mica powder is as follows: S01, stirring and mixing the layered nano mica powder in a sufficient amount of a 2% by mass sulfuric acid solution, then washing, filtering, and drying, and subjecting the dried layered nano mica powder to thermal improvement treatment to obtain a thermally regulated layered nano mica powder; S02, the heat-regulated layered nano mica powder and the modified liquid doped with alumina are modified and stirred at a ratio of 3:5, and after the stirring is completed, the modified layered nano mica powder is filtered and dried to obtain a modified layered nano mica powder; S03, adding nano titanium dioxide to a sodium lignin sulfonate solution having a volume of 3 to 5 times the total volume of nano titanium dioxide and stirring thoroughly to obtain a nano titanium dioxide agent; S04, 5 to 8 parts of modified layered nano mica powder, 3 to 6 parts of nano titanium dioxide agent and 10 to 15 parts of sodium alginate solution are uniformly blended, and then 2 to 3 parts of sodium carboxymethyl cellulose are added and continued to blend to obtain a modified auxiliary liquid doped with layered mica powder.

2. The environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas according to claim 1 is characterized in that: The stirring speed of the stirring improvement treatment is 550-600 r / min, and the stirring time is 1-2 h.

3. The environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas according to claim 1 is characterized in that: The thermal improvement treatment method is: First, heat to 255-275°C at a rate of 2-5°C / min, keep warm for 5-10 minutes, then heat to 350°C at a rate of 1-3°C / min, keep warm for 35-45 minutes, and finally air cool to room temperature.

4. The environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas according to claim 1 is characterized in that: The mass fraction of the sodium alginate solution is 4-7%; the mass fraction of the sodium lignin sulfonate solution is 4-6%.

5. The environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas according to claim 1 is characterized in that: The stirring speed of the modified stirring treatment in S02 is 550 to 750 r / min, and the stirring is performed for 20 to 30 minutes.

6. The environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas according to claim 1 is characterized in that: The modified solution for adjusting the performance of doped alumina comprises the following raw materials in parts by weight: 3 to 5 parts of nano-alumina, 1 to 3 parts of stearic acid, 2 to 5 parts of cordierite powder, 5 to 8 parts of zinc sulfate solution and 2 to 4 parts of sodium dodecylbenzene sulfonate.

7. The environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas according to claim 6 is characterized in that: The mass fraction of the zinc sulfate solution is 3-5%.

8. The environmentally friendly process for enhancing nitrogen reduction in ditch and pond sludge in agricultural areas according to claim 3 is characterized in that: The preparation method of the biochar-loaded microbial agent is as follows: S11, preparation of melamine body: Melamine and paraformaldehyde were mixed in a weight ratio of 1:3, and then distilled water and sodium hydroxide in an amount of 5 times the total amount of melamine were added, and the pH was adjusted to 7.

5. The mixture was heated to 78°C under stirring and reacted for 30 minutes. Then, terephthalaldehyde, a modifier in an amount of 10% of the total amount of melamine, was added, and the temperature was maintained and stirred for 1 hour, and the mixture was set aside to obtain a melamine body. S12, preparation of immersion solution: S121, preparing additives: 2-3 parts of hydroxyapatite and 4-6 parts of nano-silicon carbide whiskers are added to 5-8 parts of chitosan solution with a mass fraction of 4%, and then 1-2 parts of nano-silica sol are added to mix and ball-milled thoroughly at a ball-milling speed of 1500r / min for 2h. After the ball-milling is completed, the additive is filtered and dried to obtain the additive; S122, adding 5 to 8 parts of the additive to 6 to 10 parts of a 5% by mass sodium silicate solution, and then adding 2 to 3 parts of a silane coupling agent KH550 to fully blend to obtain an impregnation solution; S13, the biochar is immersed in an immersion liquid of 3 to 5 times the total amount of the biochar, and the immersion is completed to obtain an immersed biochar agent; S14, stirring the melamine body, the impregnated biochar agent and the microbial agent in a weight ratio of 2: (5-7): (3-4), filtering and drying after the stirring is completed, and obtaining the biochar-loaded microbial agent.

9. The environmentally friendly process for enhanced nitrogen reduction in agricultural ditch and pond sludge according to claim 8, characterized in that: The immersion ultrasonic power of the immersion treatment in S13 is 500-550W, and the immersion time is 30-40min; the stirring speed of the stirring treatment in S14 is 350-400r / min, and the stirring time is 25-35min.

10. The environmentally friendly process for enhanced nitrogen reduction in ditch and pond sludge in agricultural areas according to claim 8, characterized in that: The microbial agent is a bacterial solution of Bacillus subtilis, nitrite bacteria and Rhodopseudomonas palustris, which are cultured separately until the bacterial concentration OD600 reaches 3, and then mixed in a ratio of 2:2:1 and made into freeze-dried powder.

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