改性秸秆材料对高盐废水中染料和重金属的吸附性能研究

高盐印染废水是一种难处理的工业废水,其盐度高、色度高,含有染料、重金属等多种污染物.本文针对高盐印染废水中污染物的特点,设计了一种制备过程简单、成本经济的柠檬酸/丙烯酰胺改性秸秆材料(WA-CA-AM),并通过SEM、FI-IR和DTG等表征手段分别观测材料形貌、测定表面官能团和热稳定性.同时在不同盐度下,考察了单元/多元污染物体系中WS-CA-AM对4种污染物亚甲基蓝(MB)、甲基橙(MO)、铜离子(Cu~(2+))和铬离子(Cr~(6+))的吸附效果.结果表明:在单元污染物体系中,WS-CA-AM对污染物的吸附量随盐度的升高而降低;在多元污染物体系中同时存在竞争吸附和协同吸附;通过二元体系得出4种污染物的吸附受盐度影响大小顺序为MOCu~(2+)Cr~(6+)MB.在高盐度下,四元混合体系中MB和Cu~(2+)的吸附量均比染料/重金属二元混合体系的要大,Cr~(6+)的吸附量虽受到一些抑制但依然可观,表明改性秸秆材料在高盐印染废水的处理中具有巨大的应用潜力.

Adsorption properties of modified straw materials for dye and heavy metals removal in high-salt wastewater

High-salt printing and dyeing wastewater is a kind of refractory industrial wastewater with high salinity, high chroma, and contains many pollutants such as dyes and heavy metals. Aiming at the characteristics of pollutants in high-salt printing and dyeing wastewater, this paper designed a citric acid/acrylamide modified straw material (WA-CA-AM) with simple and green synthesis process and low cost. The morphology of the material, surface functional groups and thermal stability were observed by means of SEM, FI-IR and DTG. The adsorption performance of WS-CA-AM to different pollutants such as Methylene blue (MB),Methyl orange (MO), copper ions (Cu²⁺) and chromium ion (Cr⁶⁺) under different salinity in unit/multi-component pollutant system was studied. The results showed that in a single pollutant system, with the gradual increase of salinity, the adsorption amount of WS-CA-AM to pollutants gradually decreases; competitive adsorption and synergistic adsorption existed in multi-pollutant systems; the salinity resistance of four pollutants was MO>Cu²⁺ > Cr⁶⁺ > MB. Interestingly, under high salinity, the adsorption capacity of MB and Cu²⁺ in the quaternary mixed system is larger than that of the dye/heavy metal binary mixed system, and the adsorption amount of Cr⁶⁺ it is still considerable. WS-CA-AM has great potential in the treatment of high-salt printing and dyeing wastewater.