62 results about "Groundwater nitrate" patented technology

The invention discloses a permeable reactive filler for removing nitrate organisms from underground water, a system and a filling method thereof, and belongs to the field of underground water pollution remediation. The filler for the permeable reactive barrier system is formed by the mixture of biological slow release carbon source materials, pH buffer nutrient element materials and bacteria enrichment water treatment fillers, the process inlet and outlet areas of the permeable reactive barrier system are filled with water treatment filters, a process reaction area is filled with the mixture of quartz sand or basalt and fillers, and the bacteria enrichment water treatment fillers inoculated with acclimatized native denitrifying bacteria. According to the invention, slow release carbon source materials, slow release pH nutrient element materials and water treatment fillers can be flexibly added, and the shortcomings that the carbon source materials are inoculated with hang membrane materials and native microorganisms in the remediation area are insufficient are avoided. The water treatment filters in the water outlet area are capable of preventing secondary pollution.

The invention relates to a method for remedying the nitrate pollution of underground water in situ with maize straws, which is characterized in that maize straws or a maize straw hydrolysate serving as a denitrification carbon source and flora-enriched liquid rich in denitrifying bacteria florae are added in nitrate polluted underground water to remove nitrate nitrogen from underground water through bio-denitrification. The method realizes the harmless use of biomass maize straws and remedies the nitrate pollution of underground water effectively.

The invention provides a carbon source carrier filler for repairing nitrate pollution of underground water. The carbon source carrier filler is formed by cladding biological ceramsite surface with an organic carbon source coating. The coating of the carbon source carrier filler comprises the following main components of: by weight, 10-50% of a natural carbon source material powder, 10-20% of a solvent, 1-5% of trace element, 10% of animal glue, 0-5% of a deoxidant, 0-5% of a pH conditioning agent and 0-2% of a surfactant. The carbon source carrier filler prepared in the invention has good mechanical properties and biological endophilicity, can achieve the aim of long-acting sustained release of carbon source, is suitable for underground water in-situ and ex-situ remediation technologies, and can be used to effectively avoid the secondary pollution problem of additional carbon sources.

The invention belongs to the field of environment protection, and especially relates to a microbial electrochemical apparatus and a method for in-situ restoring of nitrate-polluted underground water. The apparatus is composed of an electrode restoration system, an electrode control system, an electrode liquid circulating system and a temperature control/adjusting system; through the electrode control system, the electrode restoration system is capable of intermittently at a microbe electrolysis cell state (MEC), a microbe fuel cell state (MFC) and an open-circuit state; through the electrode liquid circulating system, an electrolyte is controlled to be circulated between a cathode chamber and an anode chamber and is continuously updated; and the temperature control/adjusting system is capable of controlling the temperature of the electrode in the two electrode chambers and promoting metabolism of microbes. The advantages comprise that by employing in-situ restoration for underground water, underground water does not need pumping out, the restoration efficiency is high, the energy utilization rate is high, secondary pollution does not exist, the restoration apparatus is strong in adaptability, the restoration apparatus and the restoration process are simple, and industrial production and operation are facilitated.

A biological denitrification method is a most economical and effective groundwater nitrate pollution remediation method which is put into use currently, but has the problems of denitrification carbon source shortage, poor carbon source controlled release, easily-caused secondary pollution, and the like. Aiming at the problems, the invention provides a groundwater nitrate pollution bioremediation technology based on a semi-inert solid-phase organic carbon source carrier, which can provide a long-acting organic carbon source at the same time of taking as a denitrification bacteria carrier by utilizing the semi-inert solid-phase organic carbon source carrier as a filling medium in the groundwater nitrate pollution in-situ or ectopic remediation, ensures that the nitrate denitrification reaction can be fully finished and the groundwater nitrate pollution can be remediated economically with high efficiency and provides a powerful guarantee for groundwater safety drinking.

The invention relates to a method for remediating pollution of nitrate nitrogen in underground water, which mainly comprises the following steps: firstly, preparing Fe/Cu nanoparticles by liquid phase reduction step by step: under the protection of argon gas, reducing a FeSO4.7H2O solution with a KHB4 solution to prepare FeO nanoparticles, then introducing a CuSO4.5H2O solution into the FeO nanoparticles for continuously stirring for reacting, after reacting, washing the nano Fe/Cu solution with deoxidized and deionized water, and then, selecting the Fe/Cu nanoparticles by a magnetic method; secondly, introducing the deoxidized reaction solution into the prepared Fe/Cu nanoparticles for physically mixing simply; and finally, adding underground water containing nitrate nitrogen and sealing to carry out oscillating reaction. The method has high efficiency for remediating pollution of nitrate nitrogen in underground water, has simple required equipment and convenient operation, and provides a new way for remediating pollution of nitrate nitrogen in underground water with high efficiency and low cost.

The invention belongs to the technical field of water treatment, and in particular relates to a water treatment process and device for synchronously treating sewage, producing electricity and removing nitrate from underground water. The device consists of an anode chamber, a cation exchange membrane, a cathode chamber, an anion exchange membrane, an underground water chamber, an external circuit and the like, wherein the anode chamber and the cathode chamber are respectively used for enriching electricigens and autotrophic denitrification microbes, the electricigens in the anode chamber can decompose electrons generated by pollutants in the sewage, and then the decomposed electrons are transferred to a cathode through an anode and the external circuit; nitrate radical in the underground water chamber enters the cathode chamber through the anion exchange membrane and then is reduced into nitrogen by the autotrophic denitrification microbes, and carbonate and other anions in the underground water can be taken as a carbon source for growth of the autotrophic denitrification microbes; and the cation exchange membrane and the anion exchange membrane have extremely small pore space so as to prevent the underground water from being polluted by the microbes. The water treatment process has the advantages of low energy consumption, high efficiency, low operating cost and no secondary pollution, and is simple and easy for operation; and the device has the advantages of simple structure and convenience for large-scale industrial production and application.

The invention discloses an underground water nitrate removal method and a denitrification reactor; electrochemistry, heterotrophic aerobic denitrification and anaerobic autotrophic denitrification are combined to construct an autotrophic-heterotrophic synergic denitrification apparatus capable of providing hydrogen and oxygen. The denitrification reactor comprises an anode reaction area and a cathode reaction area which are used for carrying out heterotrophic aerobic denitrification and anaerobic hydrogenotrophic denitrification independently; denitrifying bacteria are fixed to filler by means of film colonization; since an anode and a cathode are in contact with the filler and anode and cathode plates penetrate the filler layer, gases produced may be distributed evenly in the whole reaction area during electrolytic production of hydrogen and oxygen, and denitrification efficiency is improved. A nitrate sensor is arranged in an inflow water tank to monitor the quality of inflow water in real time, an electrolytic power supply can be controlled through feedback adjustment, the magnitude of electrolytic current is adjusted, and oxygen supply and hydrogen supply are changed accordingly. The apparatus is simple in overall structure, controllable in gas supply and convenient to operate.

A device for repairing underground water nitrate pollution mainly comprises a pumping well and at least one water injection well, wherein a water suction pump is installed in a well pipe of the pumping well, a boosting pump is installed at the top of a well pipe of the water injection well, and the well pipe of the water injection well is connected with a pipeline for conveying carbon sources; well sieves are installed on the parts of the well pipes of the pumping well and the water injection well under the water level; a water conveying pipeline is connected between the water suction pump and the boosting pump; and the well pipes of the pumping well and the water injection well are respectively installed in respective protecting walls with pores of the pumping well and the water injection well, and filling materials are filled between the well pipes and the protecting walls to form a permeable reaction wall. The invention further discloses a method for repairing underground water nitrate pollution by utilizing the device.

The invention relates to a method for remediating nitrate pollution in underground water, and the advantage of the method lies in that nitrite accumulation problem caused by conventional microorganism remediation methods is solved. According to the method, a biological reaction wall portion and an aerobic well portion are comprised. The biological reaction wall consists of a solid-phase carrier medium serving as an organic carbon source that can slowly release organic carbon and oxygen capturing agent. The aerobic well is filled with solid filler that can slowly release oxygen, or a suspension of a medium that slowly release oxygen is poured into the aerobic well. The oxygen is released into underground environment by using the aerobic well, so that dissolved oxygen in the environment is improved. Nitration is carried out under an aerobic condition, so that accumulated nitrite is converted into a small mount of nitrate again. The method effectively solves the problem of excessive nitrite in effluent, nitrate content in the final effluent is small, and the concentration of the nitrate in the final effluent is lower than the III classification standard in Quality standard for ground water GB/T 14848-1993, so that no secondary pollution on the underground water will happen.

The invention provides an isotope and dating combined shallow groundwater nitrate source analysis method. The method comprises the following steps: (1) setting a monitoring sampling point and a background value sampling point according to environmental characteristics of a determination area; and (2) monitoring the age of the underground water by using an isotope dating method, and carrying out qualitative identification and quantitative analysis on the nitrate source of the underground water in combination with a nitrogen-oxygen stable double isotope tracing method, research area land utilization and pollution source information. According to the invention, underground water dating and isotope tracing methods are creatively combined. A pollution source can be quickly and accurately identified, the isotope method has the advantage of being slightly influenced by the concentration change of water environment factors, and meanwhile, the average residence time of the underground water ismeasured and compared with the formation time of the pollution source to trace back the industry category which may cause potential pollution, so that the nitrate pollution of the underground water isquickly and accurately traced back.

The invention relates to a permeable reaction material for nitrate pollution of underground water. The permeable reaction medium material consists of quartz sand, denitrifying bacteria, chitosan, CaCl2, sodium alginate, coated nano iron and a Na2HPO4-NaH2PO4 buffering solution with the pH value of 7 at a mass ratio of (1-3):(0.1-0.5):(1-3):(1.5-3):(0.5-1):(0.5-1.5):50. The invention also discloses a method for preparing the permeable reaction material. By adopting the permeable reaction medium material, not only can the carbon source be released for the growth of microorganisms, but also the reducing environment of the underground water can be enhanced, the denitrifying rate is increased, the water quality is purified, and the secondary pollution problem of the nitrate reduction product can be effectively avoided.

The invention discloses a method for restoring groundwater nitrate pollution, which comprises the following steps: (1) throwing a modified natural slow release carbon source into groundwater polluted by nitrate; (2) supplementing denitrifying bacteria enriched liquid to the groundwater with carbon source thrown in the step (1) to carry out denitrifying treatment on the groundwater. The restoring method disclosed by the invention is low in technical cost, good in nitrate nitrogen removal effect, stable in water discharge index and is simple and free of secondary pollution.

The invention provides a packing medium for a permeable reactive barrier and application of the packing medium to an aspect of in-situ treatment on underground water nitrate pollution, and a method thereof. The packing medium is formed by evenly mixing polyhydroxyalkanoate and ceramsite with the grain sizes of 4-6.5mm and 5-8mm respectively according to a ratio; raw material components of the packing medium are simple, and simple and easy to obtain. The invention also provides the application of the packing medium to an aspect of treatment on underground water nitrate pollution, in particular to the application to an aspect of in-situ treatment on underground water nitrate pollution. In addition, the invention also provides a method for in situ removal of underground water nitrate pollutants; the method takes a mixture of the polyhydroxyalkanoate and the ceramsite as the packing medium for the permeable reactive barrier. The method has the advantages of being simple and practicable, low in cost, long in service life, and small in secondary pollution, not easily causing aquifer blocking, and the like.

The invention provides an underground water nitrogen pollution source quantitative analysis method and device based on multiple tracers. The method comprises the following steps: identifying a supplysource of underground water according to an atmospheric precipitation line equation of hydrogen and oxygen isotopes and spatial distribution of the hydrogen and oxygen isotopes, and analyzing and identifying spatial distribution of surface water infiltration conditions according to spatial distribution formed by radon isotopes; identifying the pollution source of the underground water nitrate in the determination area by utilizing a characteristic interval formed by nitrate nitrogen and oxygen isotopes of different pollution sources and a mixed end member graphic method, and analyzing the influence of the domestic sewage on the underground water pollution in the determination area by utilizing the spatial distribution of the caffeine concentration; calculating contribution rates of different pollution sources to underground water nitrate nitrogen pollution of the determination area; and establishing a heat conduction convection model according to the waterfront sediment temperature information to calculate the waterfront sediment profile seepage flow. Therefore, the influence of the interaction process of the surface water and the underground water is comprehensively considered, and the dynamic characteristics of the polluted underground water supply and interaction process are quantitatively analyzed.

The invention belongs to the field of agricultural pollution prevention and control, and in particular relates to a greenhouse soil nitrate pollution modifying agent used for comprehensively modifying greenhouse soil nitrate pollution and effectively preventing and controlling underground water nitrate pollution risk in intensive vegetable planting regions, and a preparation method and a using method thereof. The greenhouse soil nitrate pollution modifying agent consists of composite liquid and effective microorganism (EM) bacteria liquid with equal mass ratio, wherein the composite liquid is prepared from sodium humate and dicyandiamide through composite proportioning; the EM bacteria liquid is bacterial liquid of fermented EM bacteria; and the composite liquid and the EM bacteria liquid are mixed according to the mass ratio of 1:1. The composite liquid and the EM bacteria liquid are combined to be irrigated and applied to soil, so that the greenhouse soil nitrate pollution can be prevented and controlled through biological and chemical control technological means, the nitric nitrogen content of the greenhouse soil can be reduced by above 10 percent, and the nitrogen utilization ratio of crops can be increased by above 15 percent.

The embodiment of the invention discloses a biological filler for removing nitrate in underground water. The biological filler is prepared from, by weight, a reducing sulfur-based material, a calciumcarbonate-based material and a bioactive material, wherein the weight ratio of the reducing sulfur-based material to the calcium carbonate-based material to the bioactive material is 1: (1-5): (0.1-0.6). The biological filler is used for solving the problems that acid and sulfate radicals are generated in a sulfur-autotrophic denitrification process and the denitrification rate is low. Effective removal of nitrate in the underground water is better achieved. The embodiment of the invention also provides a preparation method and application of the biological filler.

The invention belongs to the technical field of agricultural resources and environments, and particularly relates to a radish nitrogen fertilizer recommendation method for coordinating agronomy and the environment. The radish nitrogen fertilizer recommendation method capable of coordinating the agronomy and the environment comprises the following steps: determining a relation model between an allowable nitrate nitrogen leaching loss amount of the environment and an allowable upper limit value of nitrate nitrogen concentration in underground water; determining the critical nitrogen applicationamount of the environment according to the allowable nitrate nitrogen leaching loss amount of the environment and the relation model between the nitrogen application amount and the nitrate nitrogen leaching loss amount; determining an agronomic critical nitrogen application amount according to the radish yield and a relation model between the nitrogen application amount and the radish yield; and determining the feasibility range of the nitrogen fertilizer application amount according to the agronomic critical nitrogen application amount and the environmental critical nitrogen application amount. According to the method, agronomic and environmental benefits are coordinated, and the environmental problems that the nitrate content of underground water exceeds the standard due to excessive nitrogen fertilizer application and the like are reduced to the maximum extent.

The invention discloses a PRB (permeable reactive barrier) repair material applied to the repairing of underground water nitrate pollution. The PRB repair material is characterized by being prepared from the following ingredients by weight percent: 30% to 40% of oxygen trapping reducing agent, 10% to 15% of stabilizing and curing adhesive, 5% to 10% of autotrophic denitrification microbial agent,25% to 35% of microbial carrier material, 10% to 15% of sand and the balance of water. According to the PRB repair material disclosed by the invention, combined action of all the ingredients is utilized to achieve the effect that a filling material for repairing underground water nitrate by PRB has the functions of high efficiency, stability and better field adaptability; increasing apposition growth environment supply for microorganisms in underground water is facilitated; meanwhile, an effect of the adhesive can reduce loss of autotrophic denitrification microorganisms and reducibility ironpowder along with underground water flow and further can form a growth environment suitable for autotrophic microorganisms; iron ions formed in a repairing process can be absorbed by bentonite, so that effects of excessively releasing iron ions to downstream is reduced, and occurrence of secondary pollution is avoided; in addition, the characteristics of environmental friendliness and low cost ofthe PRB filling materials are achieved.

The invention discloses a groundwater ammonia-nitrogen in-situ enhanced nitrification and denitrification integrated system and method. The integrated system comprises an ammonia-nitrogen in-situ enhanced nitrification system, a nitrate-nitrogen in-situ enhanced denitrification system and an in-situ solution monitoring device in an aeration zone. The ammonia-nitrogen in-situ enhanced nitrification system comprises a first operating well and a water distribution pipe, wherein the first operating well is adjacent to wastes in the aeration zone, and the water distribution pipe extends to a position below the wastes to wet the lower part of the aeration zone. The nitrate-nitrogen in-situ enhanced denitrification system comprises a water pumping well, a static mixer and a water injecting well, wherein the water pumping well and the water injecting well are both arranged in a groundwater nitrate-nitrogen pollution zone around the wastes. The groundwater and the carbon-source agent are injected into the water injecting well after being mixed uniformly in the static mixer. The in-situ solution monitoring device in the aeration zone comprises a pump and at least one solution collecting pipe, wherein the solution collecting pipe is arranged in the aeration zone. By adopting the technical scheme of the invention, a very good groundwater pollution remediation effect can be achieved, and the current situation of severe water pollution of China can be improved effectively.

The invention discloses a denitrification electrode material for eliminating nitrate in underground water, and a preparation method and application thereof. The preparation method comprises the following steps: (1) subjecting waste rubber to mechanical crushing at first and sieving next, and then successively carrying out soaking with an organic solvent, cleaning with clear water, drying and calcining so as to obtain carbon black; (2) uniformly mixing the obtained carbon black with starch, adding an organic solvent and carrying out stirring until the obtained mixture is in the shape of dough;and (3) compacting the obtained mixture on a substrate made of a rigid porous material, carrying out standing until the mixture is totally dried, then punching the rigid porous material, and carryingout microbial biofilm culturing so as to obtain a single-piece denitrification electrode material. According to the invention, a plurality of single-piece denitrification electrode materials having undergone electron supplementation via a chemical approach are successively arranged in an area, where to-be-treated underground water circulates, at intervals; through holes in adjacent single-piece denitrification electrode materials are arranged in a stagger way; all the single-piece denitrification electrode materials are connected in series; and underground water is sequentially treated by thesingle-piece denitrification electrode materials so as to remove nitrate in the underground water.

The invention belongs to field of biological treatment of nitrate pollution in groundwater, and particularly relates to a preparation method of sulfur autotrophic denitrification bacterium immobilizedparticles. The preparation method of the sulfur autotrophic denitrification bacterium immobilized particles comprises the following steps that S1, polyvinyl alcohol and xanthan gum are added into deionized water, agricultural waste and sulfide which are subjected to biofilm culturing are added, and thus a material A is formed; S2, boric acid and calcium chloride are molten in the deionized water,a sodium hydroxide solution is added to adjust the pH value, then a supernatant is taken, and thus a solution B is formed; and S3, the material A is taken to be dripped into the solution B to form embedded particles, and after a cross-linking reaction is conducted, the sulfur autotrophic denitrification bacterium immobilized particles are obtained. According to the preparation method of the sulfur autotrophic denitrification bacterium immobilized particles, the mechanical properties and salt stability of the sulfur autotrophic denitrification bacterium immobilized particles can be improved, the denitrification start time is shortened, the denitrification efficiency is improved, and meanwhile, a new idea is provided for secondary utilization of the agricultural waste.

The invention discloses a denitrifying bacterium, namely pseudomonas songnenensis L103 with complete denitrifying capability and quick nitrogen removal capability, and application thereof. The strainhas been preserved in the China Center for Type Culture Collection on March 20, 2019, and the preservation number is CCTCC M 2019184. The strain has genes for encoding nitrate reductase, nitrite reductase, nitric oxide reductase and nitrous oxide reductase, the genes can encode complete denitrifying enzymes, NO3- is catalyzed to be completely reduced to generate N2, and the nitrogen removal rate can be up to 1.62-2.36 g NO3-/day/L. Therefore, the strain has important application value in the aspects such as preparation of a denitrifying microbial agent for reduction of the nitrate leaching loss and groundwater nitrate pollution in soil below a root layer, as well as purification and treatment of nitrogen-containing sewage.