5 results about "Sulfide ions" patented technology

To provide a new method for producing quantum dots of an iron-containing sulfide different from a conventional one.SOLUTION: A method for producing quantum dots of an iron-containing sulfide includes a step of preparing a mixed solution in which at least ferrous hydroxide is present in water at 0 °C or higher and 30 °C or lower, a step of preparing a green rust-containing suspension by oxidizing the mixed solution to form green rust crystals in the mixed solution, and a step of raising the temperature of the suspension to 50 °C or higher and 100 °C or lower in an oxygen-free stream. A method for producing iron-containing sulfide quantum dots, the method comprising: synthesizing the ferrite quantum dots in the slurry; collecting the ferrite quantum dots in the slurry; and treating the ferrite quantum dots with hydrogen sulfide gas at 110 °C. or more and 150 °C. or less to substitute sulfide ions O2 - for oxide ions S2 - in the ferrite, thereby producing iron-containing sulfide quantum dots.SELECTED DRAWING: Figure 1

This invention provides a method for detecting the chemical oxygen demand (COD) of a water sample containing interfering ions. The method includes: testing the content of various interfering ions in the water sample, wherein the interfering ions include one or more combinations of bromide ions, iodide ions, chloride ions, and sulfide ions; ensuring that the chloride ion concentration in the water sample is below the concentration that the masking agent used for COD detection can block; performing COD detection on the water sample to obtain the actual apparent COD value; and calculating the total interference value y of other interfering ions besides chloride ions in the water sample. 总 The measured apparent value of COD was subtracted from the total interference value y. 总 The method provided by this invention can eliminate the interference of bromine, iodine, chloride, and sulfur ions in water samples on COD detection, and has high detection accuracy and good repeatability. It solves the problem of high detection values ​​and distorted results caused by the reaction of reducing ions with the digestion system in COD detection.

This application relates to the field of acidic mine wastewater treatment and sulfide resource recovery technology, specifically providing a method and system for hydrogen-driven synergistic biological treatment of acidic mine wastewater and sulfide resource recovery. The method includes: introducing acidic mine wastewater into an HSR-MBR unit; under anaerobic conditions with hydrogen as the sole external electron donor, reducing sulfate to sulfide ions and generating alkalinity through hydrogen autotrophic sulfate-reducing bacteria; and the sulfide ions reacting with Fe... 3+ The biofilm reacts with other heavy metal ions to form insoluble heavy metal sulfide particles; these particles are periodically sludged off the biofilm; the treated mixture is then introduced into a solid-liquid separation unit for membrane separation to obtain purified effluent and sulfide-containing biomass retained by the membrane; all biomass rich in heavy metal sulfides is collected for resource recovery. This application achieves integrated treatment of acidic mine wastewater through "co-removal of pollutants and targeted conversion of resources" within a single system.

Provided is a method for producing quantum dots of an iron-containing sulfide, the method being characterized by having: a step for preparing a mixed solution in which at least ferrous hydroxide is present in 0-30°C water; a step for preparing a green rust-containing suspension by oxidizing the mixed solution to form green rust crystals in the mixed solution; a step for synthetizing quantum dots of the ferrite in the suspension by raising the temperature of the suspension to 50-100°C in an oxygen-free gas flow; a step for recovering the quantum dots of the ferrite in the suspension; and a step for treating the quantum dots of the ferrite with hydrogen sulfide gas at 110-150°C, thereby substituting the oxygen ions O2− of the ferrite with sulfide ions S2− and preparing quantum dots of an iron-containing sulfide.

The invention relates to the technical field of waste liquid treatment, in particular to a continuous process method for deeply removing lead from a rare earth chloride solution. The method solves the problems of hydrogen sulfide escape, sulfur ion residue, discontinuous process and the like in the traditional sulfide precipitation method. The method comprises the following steps: adjusting the pH value of a solution to remove thorium, and enabling the solution to sequentially pass through a first fixed bed reaction column filled with a surface activated porous reduced iron filler and a second trapping and polishing column filled with magnetic iron oxide trapping particles and titanium dioxide coating polishing particles under an anoxic condition to realize reduction precipitation and deep removal of lead; then, barium salt precipitation is used for removing radium, and cerium hydroxide wet glue is used for adsorbing co-precipitated residual radioactive elements; the process does not need to introduce sulfides, can realize whole-process continuous operation, and has the advantages of radioactive purification, high rare earth recovery rate and good process stability.