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Abstract：
This study focuses on the ability of commercial natural bath sponges, which are made from the skeletons of marine sponges, to sorb Hg from natural waters. The main component of these bath sponges is spongin, which is a protein-based material, closely related to collagen, offering a plenitude of reactive sites from the great variety of amino acids in the protein chains, where the Hg ions can sorb. For a dose of 40 mg L-1 and initial concentration of 50 μg L-1 of Hg(II), marine spongin (MS) removed ~90% of Hg from 3 water matrixes (ultrapure, bottled, and seawater), corresponding to a residual concentration of ~5 μg L-1, which tends to the recommend value for drinking water of 1 μg L-1. This value was maintained even by increasing the MS dosage, suggesting the existence of a gradient concentration threshold below which the Hg sorption mechanism halts. Kinetic modelling showed that the Pseudo Second-Order equation was the best fit for all the water matrixes, which indicates that the sorption mechanism relies most probably on chemical interactions between the functional groups of spongin and the Hg ions. This material can also be regenerated in HNO3 and reused for Hg sorption, with marginal losses in efficiency, at least for 3 consecutive cycles.
摘要：
这项研究的重点是商业天然浴海绵的能力，它们是由海洋海绵的骨架制成的，从自然水域中吸收汞。这些沐浴海绵的主要成分是海绵，这是一种基于蛋白质的材料，与胶原蛋白密切相关，从蛋白质链中的各种氨基酸中提供大量的反应位点，汞离子可以吸附的地方。对于40mgL-1的剂量和50μgL-1的初始浓度的Hg（II），海洋海绵体(MS)从3种水基质中去除约90%的汞(超纯，瓶装,和海水)，对应于〜5μgL-1的残留浓度，这倾向于饮用水的推荐值1μgL-1。即使增加MS剂量也能保持该值，这表明存在一个梯度浓度阈值，低于该阈值，汞吸附机制将停止。动力学模型表明，伪二阶方程是所有水矩阵的最佳拟合。这表明吸附机制最可能依赖于海绵体官能团与汞离子之间的化学相互作用。这种材料也可以在HNO3中再生，并重新用于汞吸附，效率的边际损失，至少连续3个周期。
