Dynamic experiment on the treatment of acidic chromium-containing wastewater by lignite loaded nano FeS. Issue 10 (18th February 2022) - Guo, Xuying
Abstract : Based on the good adsorption and reducibility of Cr(vi ) of lignite and nano-FeS, the lignite supported nano-FeS adsorption material (nFeS-lignite) was prepared by ultrasonic precipitation method to treat acidic chromium-containing wastewater. Abstract : In terms of the problem of severe pollution to the ecological environment caused by the acidic chrome-containing wastewater produced in the tanning, electroplating, metallurgy, printing and dyeing and other industries, based on the good adsorbability, reducibility and other properties of heavy metals such as Cr(vi ) by lignite and nano FeS, the lignite-loaded nano FeS adsorbing material (nFeS-lignite) was prepared by ultrasonic precipitation method. NFeS-lignite and lignite were used as fillers to construct 1# and 2# dynamic columns to carry out the dynamic treatment experiment of acidic chrome-containing wastewater. And nFeS-lignite and lignite were characterized by XRD, SEM and EDS to explore the regularity, long-acting properties and removal mechanism of acidic chrome-containing wastewater treated by NFeS-lignite and lignite. The results indicate that: ① during 25 days of operation, the average removal percentages of Cr(vi ) in the 1# and 2# dynamic columns are 71.6% and 53.1%. The average removal percentages of total chromium in 1# and 2# dynamic columns are 54.4% and 28.8%, and the average effluent pH of 1# and 2# dynamic columns is 5.3 and 7.3. ② According to XRD, SEM, EDS and FTIR analysis, the reducing groups in the structure of nFeS-lignite, such as –CH3, –CH2, C–O and Ar-OH, participate in the reaction and are oxidized to CC, CO and other groups. A large number of sediment crystals appeared on the particle surface, and new diffraction peaks such as FeOOH, Cr(OH)3 and Cr2 S3 appeared at the same time, indicating that after Cr(vi ) was reduced to Cr(iii ), it would be fixed on the surface of nFeS-lignite in the form of precipitation such as hydroxide and sulfide.