Application of N, N-diethyl-N'-m-fluoro substituted benzoyl thiourea in nickel wastewater treatment

Abstract

The invention discloses an application of N, N-diethyl-N'-m-fluoro substituted benzoyl thiourea in nickel wastewater treatment. The strong coordination of N, N-diethyl-N'-m-fluorine substituted benzoyl thiourea is used to treat nickel ion in wastewater, and the residual nickel ion content is determined by flame atomic absorption spectrometry. The results show that in the presence of flocculant polyaluminium chloride and polyacrylamide, the acyl thiourea can completely precipitate Ni (II) ions in the range of 7-8, and the residual nickel content in the simulated wastewater containing Ni(II) 500mg / L is far lower than the national discharge standard. The preparation method has the advantages that the nickel ions can be completely precipitated under the condition of being close to neutrality,and the treated waste liquid can be directly discharged without adjusting the pH value; the precipitate of the generated acyl thiourea Ni (II) complex is filtered, the nickel ions and the thiourea precipitate can be released by acidification, the enrichment of the Ni (II) and the recovery of the precipitating agent can be quickly achieved, the recovery rate of the precipitator reaches 72.1%, and the wastewater treatment cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to the application of N,N-diethyl-N'-m-fluorine substituted benzoylthiourea in nickel wastewater treatment. Background technique [0002] The toxicity of heavy metal ions has the characteristics of long-term accumulation and is difficult to degrade and destroy. It can only be concentrated and enriched by changing the valence state and compound type. Ni 2+ It is one of the common heavy metal pollutants. The reported nickel wastewater treatment methods mainly include chemical precipitation, ion exchange, oxidation, and electrolysis. Traditional hydroxide precipitation method: the pH value of the treated wastewater is often high, and it needs to be neutralized with acid before it can be discharged, and for weak amphoteric metals such as Ni, the pH value is high, and the sediment may be redissolved, so the pH value The control must be very strict. The residual...

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Problems solved by technology

Traditional hydroxide precipitation method: the pH value of the treated wastewater is often high, and it needs to be neutralized with acid before it can be discharged, and for weak amphoteric metals such as Ni, the pH value is high, and the sediment may be redissolved, so the pH value The control must be very strict. The residual nickel concentration in water after treatment by this method can be less than 1mg / L; sulfide precipitation method: because the solubility of sulfide is smaller than that of hydroxide, the treatment effect is better than that of hydroxide neutralization precipitation method. And it is convenient for metal recovery, but the price of vulcanizing agent is high, the treatment cost is high, and the sulfide precipitation particles are relatively small, easy to form colloids, and precipitation is relatively difficult, and hydrogen sulfide gas is easily generated during the treatment process, causing secondary pollution; ion exchange method : Both metal cations and anions in wastewater can be removed, and the concentration of residual nickel ions after wastewater treatment is low, and the treatment effect is good, but the cost of ion exchange resin is relatively high, and acid, alkali or salt are needed for resin regeneration, so the operation The cost is relatively high, and the regeneration solution needs further treatment; ferrite method: the improved ferrite method has good removal rate, short sedimentation time, good treatment effect and low cost, but ferrous sulfate and sodium hydroxide The amount of dosage is large, the content of sodium sulfate in the effluent is large, the process is complicated, the energy consumption is high, and the operating cost is high. It is not suitable for a large amount of wastewater treatment; the electrolytic method has high treatment efficiency and is easy to control and manage, but the equipment loss is serious. And it consumes a lot of power, and the wastewater treatment effect is not ideal and stable, so it has not been widely used

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