The invention relates to a method for removing thallium from wastewater, which can be used for removing thallium from thallium-containing wastewater, and belongs to the technical field of environmental protection. The method comprises the following steps: adding a reducing agent into the wastewater to reduce trivalent thallium in the wastewater into univalent thallium under a sufficient stirring condition, sufficiently mixing a potassium ferrocyanide solution and an excessive amount of ferric trichloride solution to obtain a mixture of Prussian blue, ferric trichloride and water, adding the mixture into the wastewater, adding a ferric coagulant solution, and performing stirring and solid-liquid separation to separate thallium in a solid phase from a water body, namely remove the thallium from the wastewater. The method has the characteristics of low thallium removal cost, simple thallium removal process, no secondary pollution and the like, and is also very suitable for thallium removal treatment of thallium-containing wastewater with relatively high COD.

Method for removing thallium from wastewater

The invention discloses a method for recycling waste gas generated by rare earth electrolyzed by a fluoride system. The method includes the steps: treating the waste gas generated by electrolysis by adust removal device, leading in lithium hydrogen carbonate serving as absorbing agents to perform chemical absorption on a spray absorption tower, directly leading the chemically absorbed waste gas with carbon dioxide serving as a main component in a lithium carbonate liquid tank, converting lithium carbonate into the lithium hydrogen carbonate with high solubility, injecting the lithium hydrogencarbonate into the spray absorption tower to be recycled, and continuing to capture fluorine ions in fluorine-containing gas; performing solid-liquid separation, washing, drying and high-temperaturedehydration on a new substance generated after spraying absorption to obtain lithium fluoride for electrolyzing rare earth. According to the method, rare earth dust and fluorine-containing tail gas are firstly separated, the lithium hydrogen carbonate serves as a capturing agent of the fluorine ions, the comprehensive yield can reach 84.50% or more, the comprehensive yield of a system reaches 96%or more after reaction is completely balanced, carbon dioxide in the absorbed waste gas serves as a raw material to be directly led into the lithium carbonate liquid tank to circularly prepare a lithium hydrogen carbonate absorbing agent, and emission of the carbon dioxide is greatly reduced.

Method for recycling waste gas generated by rare earth electrolyzed by fluoride system

The invention discloses a PCB ink wastewater purification treatment technology. The PCB ink wastewater purification treatment technology comprises the following steps of raw material preparation, flocculating settling, freezing treatment, Fenton oxidation, electric flocculation treatment, flocculating settling, freezing treatment, plate-and-frame filtration, TMF filter treatment, MBR reactor treatment and inspection tank treatment. According to the ink wastewater purification treatment technology, by means of addition of freezing treatment and cooperative usage of a pressure filter and a plate-and-frame filter, most of insoluble substances and weak soluble substances in ink wastewater are precipitated out and separated, consumption of consumables and usage amount of additives are greatly reduced, the benefit ratio is high, the cost is not significantly increased, continuous purification can be conducted, faults are not prone to occur, the purification capacity is prominent, all indexes of finally discharged wastewater all exceed the national emission standard, and the PCB ink wastewater purification treatment technology is obviously superior to the prior art.

PCB ink wastewater purification treatment technology

The invention discloses a method for simultaneous removal of HF and SO2 from electrolytic aluminum flue gas with electrolytic aluminum ash and slag. The method takes a slurry made of electrolytic aluminum ash and slag as the absorbent for liquid phase catalytic oxidation on HF and SO2 in electrolytic aluminum flue gas so as to reach the purpose of simultaneous removal of HF and SO2 from electrolytic aluminum flue gas. The method achieves removal of HF and SO2 from the flue gas through the catalytic oxidation effect of the metal oxide and transition metal ions contained in the aluminum ash and slag. The method provided by the invention has the advantages of simplicity, high reserve and easily available raw materials, low cost, easy realization of industrial application and good removal effect, the side product aluminum fluoride can be recycled, and the method realizes waste control by waste and clean production.

Method for simultaneous removal of HF and SO2 from electrolytic aluminum flue gas with electrolytic aluminum ash and slag

The invention discloses a method for recovering oxalic acid by the solid-solid transformation of calcium oxalate waste residue, which comprises the following steps: mixed waste residue is mixed with concentrated sulfuric acid, and after uniform agitation, curing reaction takes place; after the two phases are cured, solid-solid roasting transformation is carried out in a reactor, so that calcium sulfate and oxalic acid mixed crystals are obtained; water is then used for slurrying the mixed crystal product, and after mixing, extracting and filtration, an oxalic acid solution is obtained. The oxalic acid transformation efficiency of the method is high, the consumption of sulfuric acid is little, and defects existing in conventional processes, such as a large remaining amount of acid, long process flow and high recovery cost, are overcome.

Method for recovering oxalic acid by solid-solid transformation of calcium oxalate waste residue

The invention provides treatment method and equipment of a beta-naphthol production wastewater. The equipment comprises a collecting tank, a high-efficiency air-flotation reactor, an acidification tank, a micro-electrolysis tower, a pipeline mixer, a Fenton reactor, a neutralization coagulation reaction pool, a compound sedimentation pool, an adjusting and cooling pool, a hydrolysis acidification pool, a mobile bed biofilm reaction tank, a contact oxidation tank, a secondary sedimentation tank, an intermediate tank, a prefilter, a catalytic oxidation tower and a biological aerated filter. Through an application method of the equipment, the problem that the beta-naphthol production wastewater is high in COD, high in chromaticity and difficult to degrade is solved, and long-period stable emission on standard of the beta-naphthol production wastewater is ensured.

Treatment method and equipment of beta-naphthol production wastewater

The invention relates to the field of recycle treatment of rare earth wet-method smelting waste water, and especially relates to a process of recycling oxalic acid from rare earth wet-method smelting oxalic acid precipitation waste water. The process disclosed in the invention comprises following steps: adding alkaline calcium ion to the rare earth oxalic acid precipitation waste water, performing solid-liquid separation to collect the solid calcium oxalate, adding dilute sulfuric acid to the solid calcium oxalate, performing solid-liquid separation to obtain a liquid, decreasing the liquid to 0-15 DEG C and performing crystallization to obtain high-purity oxalic acid. The method can effectively recycle the oxalic acid from the rare earth wet-method smelting oxalic acid precipitation waste water with the recycle rate being not less than 50% and the purity of the recycled oxalic acid being not less than 95%. Meanwhile, the method is free of products such as ion exchange resin and the like and is also free of a complex column chromatographic process, so that the method is low in treatment cost, is simple and reliable and is suitable for industrial popularization.

Process of recycling oxalic acid from rare earth wet-method smelting oxalic acid precipitation waste water

The invention belongs to the field of environmental protection and particularly relates to a deep phosphorus removal method for organophosphorus wastewater. In order to achieve the deep phosphorus removal of the organophosphorus wastewater, the invention provides the deep phosphorus removal method for the organophosphorus wastewater. The deep phosphorus removal method comprises the following steps: (1) adding 30wt% hydrogen peroxide into the organophosphorus wastewater; (2) introducing ozone into the wastewater; (3) adding ferrous salt which accounts for 0.01%-5% of mass of the wastewater; and (4) adjusting the pH of the wastewater to 6-9, adding polyacrylamide into the wastewater solution, standing and settling. By the method disclosed by the invention, the removal rate of total phosphorus in the organophosphorus wastewater reaches not less than 99%, the amount of total phosphorus in the effluent water is not less than 0.5mg/L, which meets the total phosphorus requirements of sewage discharge standards GB8978-1996 and the phosphorus removal process disclosed by the invention is low in cost and has practical promotion significance.

Deep phosphorus removal method for organophosphorus wastewater

The invention discloses a novel hydrogen fluoride gas control and recycling method The method mainly comprises the following steps: (1) collecting hydrogen fluoride gas in a concentrated manner by utilizing a fan, connecting the outlet of the fan into a spray tower containing lithium hydrate absorption liquid, and carrying out spraying absorption on the hydrogen fluoride waste gas; (2) completely absorbing the hydrogen fluoride gas by utilizing the lithium hydrate absorption liquid (wherein the generated reaction is HF and LiOH generate LiF and H2O), monitoring the pH of the spraying absorption liquid, and draining the spraying absorption liquid after complete reaction into a water collecting box; and (3) adding lithium hydrate solid into the spraying absorption liquid in the water collecting box, stirring, separating lithium fluoride out by utilizing common ion effect, and carrying out solid-liquid separation, wherein the obtained solid is recycled, and the liquid is put into cycle use after returning to the step (1)

Hydrogen fluoride waste gas control and recycling method and equipment

The utility model discloses a brand -new hydrogen fluoride waste gas pollution control and treatment and utilization's equipment, a serial communication port, including fan, spray column, header tank, crystallization reactor and centrifugal separator, the export of fan links to each other with the spray column, the spray column bottom is connected with the header tank, header tank bottom links to each other with the spray column top through the pump, the pump still links to each other with the crystallization reactor, the crystallization reactor links to each other with the centrifugal separator, the centrifugal separator links to each other with the header tank

Wang Zhilei

Papers

Treatment method and equipment of beta-naphthol production wastewater

Process of recycling oxalic acid from rare earth wet-method smelting oxalic acid precipitation waste water

Deep phosphorus removal method for organophosphorus wastewater

Hydrogen fluoride waste gas control and recycling method and equipment

Hydrogen fluoride waste gas pollution control and treatment and utilization's equipment