9 results about "Reductive dechlorination" patented technology

The invention relates to a biochar-loaded nano zero-valent iron repair material as well as a preparation method and application thereof. The biochar loaded nano zero-valent iron repair material is prepared from a persulfate-biochar carrier and metal sulfide modified composite acid stabilized nano zero-valent iron sol, the composite acid is composed of gallic acid and humic acid / fulvic acid; the preparation method comprises the following steps: S1, preparing a persulfate-biochar carrier; and S2, preparing the biochar loaded nano zero-valent iron repair material. The method is applied to groundwater chlorohydrocarbon pollution remediation. According to the method, in the reductive dechlorination process of the nano zero-valent reduced iron, released Fe < 2 + > can strengthen persulfate, Fe < 2 + > is regenerated by utilizing the reduction effect of gallic acid on reacted Fe < 3 + >, and catalytic circulation of iron is maintained; humic acid / fulvic acid is used for efficiently driving the degradation process; and metal sulfide is utilized to catalyze reduction of organic chlorine chemicals, so that the reductive dechlorination performance of the nano-iron material is improved, and the repairing effect of chlorinated hydrocarbon is optimized.

The invention discloses acetochlor reductive dechlorination enzyme ArdA as well as a coding gene and application thereof. The nucleotide sequence of the arcA is SEQ ID NO.1, the full length of the arcA is 681 bp, the amino acid sequence of the arcA is SEQ ID NO.2, and 226 amino acids are encoded. ArdA is the acetochlor reductive dechlorination enzyme found for the first time, can be used for degrading acetochlor residues in soil and water, and has very important theoretical and application values.

This invention discloses a method for remediating halogenated hydrocarbon pollution based on functional plasmid transformation, belonging to the field of environmental microbial remediation technology. The method first extracts plasmid DNA carrying functional genes from organobacteria with reductive dechlorination capabilities (organobacteria with halogen respiration). Then, the functional plasmid DNA and electron donors are directly added to halogenated hydrocarbon-contaminated samples containing indigenous microorganisms to construct a bio-enhanced remediation system. Finally, the system is cultured under anaerobic conditions to transform the functional plasmid into the indigenous microorganisms, thereby endowing or enhancing the indigenous microorganisms with the ability to reductively dechlorinate halogenated hydrocarbon pollutants. This invention avoids the ecological risks of directly introducing exogenous live bacteria. Through plasmid-mediated horizontal gene transfer, it rapidly activates and enhances the function of in-situ microbial communities, significantly improving the degradation rate and thoroughness of halogenated hydrocarbon pollutants, and providing an efficient, safe, and universally applicable technical means for in-situ bioremediation of contaminated sites.

The invention relates to an HCH contaminated soil remediation agent and a remediation method. The repairing agent is composite zoogloea loaded biochar-nano zero-valent iron microspheres with the particle size of 20 to 40 meshes; the composite zoogloea loaded biochar-nano zero-valent iron microspheres are prepared from gel microspheres embedded with a composite zoogloea-biochar compound and a biochar-nano zero-valent iron composite material according to the weight ratio of 1 to (1 to 3); the remediation method comprises the following steps: S1, soil pretreatment; s2, applying a repairing agent; according to the method, firstly, nanoscale zero-valent iron is used for reductive dechlorination, high-chlorinated HCH is converted into a low-chlorinated benzene compound, then microorganisms such as sphingomonas are used for degrading an intermediate product, the repairing efficiency is greatly improved, meanwhile, the sphingomonas in the composite zoogloea is used for treating an HCH molecular ring firstly, and therefore the repairing efficiency is greatly improved. And then, the strain of the pseudomonas putida opens a benzene ring, compounds such as benzene, methylbenzene and phenols are used as carbon sources and energy sources, and finally, the compounds are thoroughly mineralized, so that the remediation effect of HCH pollution is effectively improved.

The application discloses a preparation method and application of a semiconductor mineral composite functional biomaterial for promoting reductive dechlorination, and belongs to the technical field of environmental biological remediation. The application solves the problems of slow metabolic rate and unstable degradation capacity of dechlorination respiratory bacteria in the existing biological remediation process. The semiconductor mineral is compounded with dechlorination respiratory bacteria such as pseudomonas aeruginosa, the conductive property of the semiconductor mineral is utilized, the electron transfer process in the microbial community and the growth and metabolism process of the dechlorination respiratory bacteria are promoted, and finally the microbial dechlorination of CPs is enhanced.

This invention discloses a method for preparing and applying biochar-based microbial agents for reductive dechlorination, belonging to the fields of environmental engineering and pollution treatment engineering technology. This invention solves the problems of existing anaerobic reductive dechlorination reactions where dehalogenating respiratory bacteria struggle to withstand load shocks and highly heterogeneous environmental media, and are difficult to stably and scalably prepare biochar-immobilized microbial agents. This invention utilizes surfactants to modify biomass biochar, enhancing its hydrophilicity or electron transfer efficiency, and employs mixed anaerobic cultivation to ensure a more uniform distribution of dehalogenating respiratory bacteria on the modified biochar, significantly increasing the microbial loading. The resulting biochar-immobilized microbial agent material loaded with dehalogenating respiratory bacteria integrates adsorption and bioremediation functions, increasing its continuous action time in the soil while minimizing the impact of external substances on the soil. It is an ideal in-situ soil bioremediation material.

The present invention belongs to the technical field of wastewater treatment. Disclosed are a conductive material-loaded bio-electrochemical system device for removing a trichloroethylene contaminant, and a method. Wastewater to be treated containing trichloroethylene is introduced into a bio-electrochemical system device inoculated with a dechlorination mixed microbiota; microorganisms colonize the surface of a cathode carbon brush to form an electroactive dechlorinating biofilm; electrons flow through an external circuit to a cathode so as to be used by the microorganisms; nano-magnetite and activated carbon enhance the reductive dechlorination of trichloroethylene by enhancing electron transfer. The present invention can completely convert trichloroethylene to ethylene and completely reduce 500 μM of trichloroethylene within 12-15 days, couples electrochemical technology with microbial dechlorination technology, and has the advantages of low cost, environmental friendliness and in-situ repairability.

The invention relates to the technical field of wastewater treatment, and discloses a method for treating chlorine-containing wastewater, which comprises the steps of pretreatment, acidification, reductive dechlorination reaction, pH value regulation and recycling, and comprises the following steps: firstly adding hydrochloric acid into the chlorine-containing wastewater for acidification, then adding sodium thiosulfate for reduction, collecting chlorine released from the wastewater, and recycling the chlorine-containing wastewater. The residual chlorine can be prevented from volatilizing to an operation environment, so that the odor can be removed, the air quality of a workshop can be improved, and occupational health and safety standards are met; after reductive dechlorination treatment, the content of residual chlorine in the wastewater is reduced, and when the wastewater is fed into an MVR evaporation system, corrosion to metal equipment can be greatly reduced, the service life of the equipment is prolonged, the frequency of maintenance and shutdown is reduced, the maintenance cost is reduced, and the production continuity is guaranteed; meanwhile, the treated reclaimed water can reach the standard and be recycled to reduce the consumption of fresh water resources, and the captured chlorine can be reused for chlorination reaction, so that waste recycling is realized, and the concept of environmental protection and sustainable development is met.

This invention discloses a method for anaerobic bioremediation of chlorinated hydrocarbons driven by PBSA as a slow-release electron donor, belonging to the field of in-situ bioremediation technology for soil and groundwater. The method is as follows: 1) A mixed dechlorination bacterial community containing obligate organohalogen-respiring bacteria and their symbiotic bacteria is cultured to the logarithmic growth phase to obtain a mixed dechlorination bacterial solution; 2) Anaerobic digested sludge is mixed evenly with the mixed dechlorination bacterial solution to obtain a mixed inoculum; 3) The mixed inoculum is added to groundwater contaminated with chlorinated hydrocarbons, and PBSA is added as a slow-release electron donor to drive the reductive dechlorination reaction of chlorinated hydrocarbons under anaerobic conditions, thereby removing the pollutants. This invention solves the problems of easy dilution and high risk of secondary pollution associated with traditional liquid carbon sources, as well as the high cost and low dechlorination efficiency of existing slow-release materials. Using PBSA as a slow-release electron donor results in an increasing dechlorination rate and high electron utilization efficiency. Industrial-grade PBSA is inexpensive, and this invention provides an efficient, green, and low-cost solution for in-situ remediation of chlorinated hydrocarbons in groundwater.