Adsorption and desorption properties of modified feather and feather/polypropylene melt-blown filter cartridge of lead ion (Pb ²⁺ )

Duck and chicken feather fibers are waste products of the poultry industry, creating a serious solid waste problem around the world. Previous works showed that feather fibers can be reused to adsorb heavy metal ions from water. But the raw feather fiber only exhibits moderate heavy metal ions adsorption capacity, not cost-effective to be reused as adsorbent in a large scale. To improve the adsorption capacity of feather fibers, sodium pyrosulfite (Na ₂ S ₂ O ₅ ) was used in this paper to modify the feather fiber in order to improve its Pb ²⁺ adsorption capacity. Scanning electron microscopy and Fourier transform infrared spectroscopy quantified chemical and structural changes of Na ₂ S ₂ O ₅ -modified feather fibers. In addition, Na ₂ S ₂ O ₅ -modified feather fibers were processed into feather/polypropylene melt-blown filter cartridges and their dynamic Pb ²⁺ adsorption properties were investigated by using the test equipment set up in our lab. Finally, the desorption effects of NaOH and sodium sulfide nonahydrate (Na ₂ S·9H ₂ O) aqueous solutions on the feather fiber adsorbed with Pb ²⁺ were studied. It is found that Pb ²⁺ adsorption capacity of the feather fiber increased after being modified by Na ₂ S ₂ O ₅ . Modified feather/polypropylene filter cartridge exhibited higher Pb ²⁺ adsorption capacity than feather/polypropylene filter cartridge and pure polypropylene filter cartridge in the whole dynamic adsorption process.