69 results about "Nitrate pollution" patented technology

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 discloses a catalyst which can optically catalyze and degrades benzene and nitrate, a preparation method and application of the catalyst. The catalyst is dual-metal A-B-TiO2-typed catalyst carried by TiO2; wherein, metal A is Pd, Pt or Au; metal B is Cu, Ag or Ni. The preparation method comprises the steps as follows: TiO2 is added into solution of A salt or B salt, dipped and dried by steaming; the catalyst is subsequently gained by a reduction method under the conditions of H2 and high temperature. The invention takes TiO2 carried by dual metals as catalyst; when the optical catalysis is carried out, the benzene and nitrate pollutant in water can be degraded; the operation is simple, the raw material is easily gained, furthermore, the catalyst has no secondary pollution, the disposal effect is obvious and the catalyst has wide application prospect in micro-polluted water disposal field.

The invention discloses an in-situ remediation method for nitrate pollutions in groundwater, which is characterized by comprising the steps of crushing low-grade siderite ores, and screening the obtained object so as to obtain particles with a particle size of 0.1-1 mm; excavating a groove in an aquifer perpendicular to the flow direction of groundwater, and filling the siderite particles into the groove so as to build an underground permeable wall; and injecting nitrate-dependent iron oxidizing bacteria liquid for oxidizing siderites and reducing nitrates in the presence of iron oxidizing bacteria of anaerobic microorganism depended nitrates. New iron oxides also have a function of absorbing other pollutants in purified water.

The invention relates to the technical field of water body nitrate pollution treatment and control, and is a method for culturing a denitrifying bacterium and using the bacterium to determine water body nitrate nitrogen isotopic composition. The method comprises the following steps of: (1) carrying out enrichment culture of the denitrifying bacteria, (2) detecting whether the denitrifying bacteria completely converse NO3- in a culture fluid, (3) concentrating of the denitrifying bacteria, (4) adding the concentrated cell culture to a sample bottle, purifying an upper space and removing N2O in the denitrifying bacterium liquid, (5) conversing NO3- in the sample to N2O, (6) determining the N2O nitrogen isotope, and (7) correcting the nitrogen isotope determination result to complete the test. The positive effects of the invention are as follows: the culture of the denitrifying bacteria can be completed by using only a common saline bottle or a triangular flask, the detection of sulfanilamide color development improves the reliability of the determination result, and the determination cost is reduced. For the current situation that severe water body nitrate pollution is urgently needed to be treated, the method of the invention has the advantages of scientificalness, simplicity, and high maneuverability, and has a broad popularization prospect.

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 disclosed relates to a method and apparatus for the denitrification of groundwater in situ in an aquifer under substantially anaerobic conditions, the method comprising (a) providing a network, including an extraction well for removal of groundwater from the aquifer and a plurality of injection wells for returning groundwater to the aquifer, the injection wells being arranged in a line substantially perpendicular to the direction of groundwater flow, the extraction well being located downstream or upstream of the line of injection wells, and the spacing of the wells and the number of injection wells being determined by the mathematical relationship <math-cwu id="MATH-US-00001"> <number>1</number> $\begin{array}{cc}J=\frac{C_p+{\mathrm{nC}}_1}{W}\to \min & \left(1\right)\end{array}$ <mathematica-file id="MATHEMATICA-00001" file="US20020020664A1-20020221-M00001.NB"/> <image id="EMI-M00001" wi="216.027" he="18.00225" file="US20020020664A1-20020221-M00001.TIF" imf="TIFF" ti="MF"/> </math-cwu> where J is the cost of treatment, Cp and C1 are the costs of extraction and injection wells, respectively; n is the number of injection wells, and W is the distance across the protected area, and wherein the water stream is evenly distributed between injection wells, according to the relationship: <paragraph lvl="0"><in-line-formula>Fl=Fe/n=const (2) </in-line-formula>where F is the water flow rate (e-extraction well, i-injection well) and n is the number of injection wells, (b) removing groundwater from the aquifer by the extraction well, (c) adding a carbon source to the groundwater in a controlled manner, (d) returning the carbon source amended groundwater to the aquifer by the injection wells in even distribution, the water flow rate being controlled, and (e) monitoring the nitrate concentration of the groundwater removed from the extraction well, a decrease in nitrate concentration being indicative of denitrification.

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 discloses a method for preventing and controlling nitrate leaching loss of soil in a dry farming land of North China Plain by utilizing a mode of interplanting corn and soybean. Aiming at the problems that a dry farming land of the North China Plain is rainy and hot synchronously, the fertilizing amount of single culture of corn is large, the residual quantity of nitrate nitrogen in soil is large, the risk of nitrogen leaching loss is very high, the method effectively controls nitrate leaching loss of soil by interplanting corn and soybean summer sowing season. According to the invention, appropriate irrigation is performed during sowing; open type management is adopted during the growing period of crops; optimized fertilization is performed to corn bands and soybean bands respectively; the fertilizing amount is subjected to the local recommended fertilizing amount of corresponding crops, and fertilizer is applied between rows of corresponding crops; and during the critical growing period of the crops, if rain water is sufficient, irrigation is not performed, and if no rain comes or rain water is insufficient, appropriate irrigation is performed. The method can be implemented to effectively prevent and control the risk of nitrate pollution of a dry farming land of North China Plain, and has relatively remarkable economic benefits and environmental benefits.

The invention discloses a microbial fuel cell for in-situ remediation of nitrate pollution of underground water. The microbial fuel cell is in an integral cylindrical structure and comprises an anode chamber, a cathode chamber, an anion-exchange membrane assembly and an external circuit system, wherein the anode chamber is externally arranged at the outer side of the cathode chamber in a sleeving manner, a water inlet pipe and an exhaust pipe are arranged on the top of the anode chamber, a biological anode is arranged in the anode chamber, anaerobic electricity-generating microorganisms are attached to the biological anode, the anode chamber is filled with an anode liquid and the anode liquid is organic wastewater; a water outlet pipe is arranged on the top of the cathode chamber, a biological cathode is arranged in the cathode chamber, electric active denitrification microorganisms are attached to the biological cathode, the cathode chamber is filled with a cathode liquid, and the cathode chamber is inoculated with efficient anaerobic denitrification microorganisms; the anion-exchange membrane assembly comprises an anion-exchange membrane and a carrying layer; the external circuit system comprises an external circuit, a lead and an electric signal collecting recorder. The microbial fuel cell disclosed by the invention has triple functions of removing organic wastes, generating electricity by the microorganisms and carrying out the in-situ remediation on the nitrate pollution of the underground water, is simple and compact in structure, is economic and efficient, and can continuously and stably operate.

The invention belongs to the technical field of water nitrate pollution treatment and control, and in particular relates to a measurement method of nitrogen and oxygen stable isotope of nitrate in seawater. The method comprises the steps of carrying out off-line treatment on the nitrate in the seawater to be measured by denitrifying bacteria without N2O reductase activity, and then converting the treated nitrate into nitrous oxide gas; and carrying out on-line continuous measurement on the nitrogen and oxygen stable isotope by combining a trace gas pre-concentrating apparatus (Precon) and gas chromatography (GC)-isotope ratio mass spectrometer (MS). After the measurement method is used, a culture method of the denitrifying bacteria is optimized, a formula of a culture medium is improved, the nitrate is not added, the cultivation effect is relatively good, the growth of the bacteria is stable, whether the culture medium has the residual nitrate or not after enrichment culture is not required to be tested, and the pollution is not caused in the subsequent sample treatment; the culture medium is good in bacteria enrichment effect, short in bacterial culture period and high in efficiency, and the cultivation cost is reduced.

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 invention discloses a purifying agent for nitrates in water and application of the purifying agent, and aims to solve the technical problems that in an existing treatment technology, application is limited, secondary pollution is caused, and the nitrogen removal efficiency is low. The preparation method of the purifying agent for the nitrates in the water comprises the steps that biomass is ground and screened to prepare charcoal; iron-modified charcoal is prepared by adding a FeCl3 solution; the purifying agent for the nitrates in the water is prepared by adding acrylamide, N,N-methylenebisacrylamide and ammonium persulfate. The invention further provides a treatment method of the nitrates in a water system. The treatment method comprises the steps that pH and temperature of to-be-treated disposal sewerage are adjusted; the purifying agent for the nitrates in the water is added, and then the nitrates can be removed. The purifying agent for the nitrates in the water can be used for treating production wastewater, has the effect of preventing and controlling agricultural non-point source pollution and can be further used for treating nitrate pollution to drinking water, relieving harm, caused by the drinking water high in nitrate content, to the human health, preventing further deterioration of the water and providing an effective measure for protection of a water source.

The invention discloses P. denitrificans/S. oneidensis/graphene/calcium alginate denitrifying gel microsphere as well as preparation method and application thereof, and belongs to the technical fieldof environmental protection. According to the invention, calcium alginate is adopted to embed denitrifying microorganisms P. denitrifians, S. oneidensis MR-1 and graphene to form P. denitrifians/S. oneidensis MR-1/graphene/calcium alginate denitrifying gel microspheres, and the prepared microspheres have strong resistance to toxic and harmful environmental impact, and can realize recycling of strains and materials. When the microsphere is applied to an anaerobic denitrification system polluted by nitrate or co-polluted by nitrate, the time required by reaching 90% of nitrate removal rate can be greatly shortened, and the accumulation of intermediate products nitrite and nitrous oxide is reduced.

The invention relates to a wastewater treatment method, and discloses a treatment method of stainless steel pickling wastewater. The treatment method of the stainless steel pickling wastewater comprises the following steps: firstly, using 0.05mol / L dilute sulfuric acid for cleaning iron powder for 1 ~ 2 times, then cleaning with deionized water, drying for standby use; adding the iron powder to the stainless steel pickling waste water for water bath heating, stirring evenly, and filtering with a 0.22 mum microfiltration membrane. The treatment method can remove nitrate in the wastewater, can remove Cu <2+>, Ni <2+>, Cr <6+> and other heavy metal ions to a certain extent, and can be widely used for the repair of nitrate pollution in groundwater.

The invention discloses a method and a device for in-situ remediation of groundwater pollution by electrically driven biological PRB (permeable reactive barrier). The device comprises a PRB, microorganisms, an anode, a cathode and an external circuit element device, the anode is mounted in the PRB and forms a biological PRB anode region together with the microorganisms; a water guide wall is arranged between the biological PRB anode region and the biological PRB cathode for separation; the cathode and the anode are connected with an external circuit element to jointly form an external circuit; the external circuit adopts closed-open-closed cycle operation, and generates and regenerates an iron oxide oxidation zone and an iron oxide reduction zone in situ according to pollutant properties and water quality requirements; and a filler of the PRB is a mixed filler of a conductive carbon material and a zero-valent iron material, and the mass ratio of the conductive carbon material to the zero-valent iron material is 0.1%-50%. According to the method provided by the invention, underground water petroleum hydrocarbon, halogenated hydrocarbon and nitrate pollution can be remarkably resolved, the cost is low, and the risk of secondary pollution does not exist.

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 heterotopic electron compensation hydrogen autotrophic denitrification nitrogen removal device, and relates to an autotrophic denitrification nitrogen removal device. The invention aims to solve the problems of low denitrification efficiency and low rate of nitrate polluted water body lack of electron donors. The device consists of a hydrogen production chamber, a denitrification chamber, an anode, a cathode, a gas diffusion film and a direct-current power supply, wherein the hydrogen production chamber and the denitrification chamber are separated through the gas diffusion film; or the device comprises a gas diffusion device, wherein the gas diffusion device is arranged at the gas outlet end of the hydrogen conveying pipeline. According to the device, hydrogen generated by the bioelectrochemical system is heterotopic used for hydrogen autotrophic denitrification, the inherent limitation on the electrode spacing during denitrification is broken through, the total nitrogen removal rate can be increased, the utilization rate of electrons recovered by the anode is increased, and secondary pollution to a water body is avoided. The device is suitable for sewagetreatment.

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 relates to a method for preventing nitrate from polluting underground water. The method includes laying a layer of waterproof and breathable materials on the lower portion of a cultivation soil layer or a livestock and poultry excrement yard; preventing infiltration of nitrogenous rainwater or irrigation water by the aid of the special breathable and waterproof performances of the waterproof and breathable materials; and collecting and guiding the nitrogenous rainwater or irrigation water into a nearby reservoir to realize recycle of nitrogenous fertilizer and the water. The method has the advantages that due to the stopping effect of the layer of waterproof and breathable materials, nitrate pollution of the underground water is prevented, the collected nitrogenous rainwater and irrigation water can be recycled, the application quantity of nitrogenous fertilizer and consumption of irrigation water for crops are greatly reduced, and the method is particularly applicable to intensive crop farming and the intensive breeding industry.