Efficient removal of p-arsanilic acid using a waste-derived collagen fiber-Zr composite membrane

Para-arsanilic acid ( p -ASA) is widely used as a feed additive, making it a pervasive environmental pollutant. Due to its migratory and transformative nature, p -ASA can easily convert into more toxic inorganic arsenic during its migration, thereby increasing the ecological burden and posing a threat to human health. Efficient removal of p -ASA from water is crucial for mitigating arsenic contamination. Efficient removal of p -ASA from water is crucial for mitigating arsenic contamination. This study introduced zirconium-loaded collagen fiber membrane (CFM Zr), a novel, sustainable membrane adsorption material synthesized by retanning collagen fiber membranes (CFM) with zirconium (Zr). Leveraging the physicochemical properties of CFM and the strong affinity of Zr for p -ASA, CFM-Zr achieved highly efficient p -ASA removal. The resulting membrane was made entirely from green, low-carbon and recyclable raw materials, achieving sustainable removal of p -ASA while realizing the concept of treating waste with waste for environmental recovery. Remarkably, the retanning with zirconium significantly enhanced the Zeta potential of CFM Zr, strengthening its electrostatic attraction to p -ASA, with a maximum adsorption capacity of 289.02 mg·g −1 , which was 19.72 times higher than that of the CFM before retanning (13.95 mg·g −1 ). Its adsorption rate constant was 12.54 mg·g −1 ·min −1 . Moreover, CFM-Zr showed good reusability and exhibited electrostatic adsorption and metal coordination effects on the “organic” parts (-OH, -NH 2 ) and “inorganic” parts (As O) of p -ASA, effectively removing it. This work provided a promising bio-based material for water purification, promoted the sustainable utilization of leather industry waste, and offered significant advancements in environmental remediation and resource recovery.