Abstract Substituted phenols, such as 4-Nitrophenol (4-NP) and 2,4-Dichlorophenol (2,4-DCP), that are present in industrial wastewaters are considered as priority pollutants due to their toxic effects. Their removal by biosorption presents an eco-friendly, cost-effective method. The kinetics of removal of 4-NP and 2,4-DCP by untreated Nostoc sp. (UNB) and Fe-treated Nostoc sp. biomass (FNB) were studied at three different pH (4.0, 7.0 and 9.0). The highest sorption of both phenols (2.28 mg 4-NP and 1.51 mg 2,4-DCP g−1) coupled with the lowest cumulative percentage desorption was recorded with FNB at pH 7.0. The sorption of both phenols by UNB and FNB was best accounted for by pseudo-second-order kinetics. Compared to UNB, FNB had significantly higher equilibrium sorption capacities for both phenols at all the three pH values and also higher sorption rate constants of 4-NP at pH 4 and 9 and of 2,4-DCP at pH 4 and 7. The Fourier transform infrared spectroscopy (FTIR) analysis showed that –OH and COO− groups of UNB interacted with Fe+3. The sorption of 4-NP and 2,4-DCP on UNB was likely through H-bonding/structural cation bridging with the phenolic group, while their sorption onto FNB appeared to be a complexation reaction with very low reversibility.

中文翻译：

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铁处理和平衡 pH 对发菜从合成废水中去除某些取代酚的动力学的影响。生物量

摘要工业废水中存在的取代酚，例如 4-硝基苯酚 (4-NP) 和 2,4-二氯苯酚 (2,4-DCP)，由于其毒性作用而被视为优先污染物。通过生物吸附去除它们是一种环保、经济的方法。未经处理的发菜去除 4-NP 和 2,4-DCP 的动力学。(UNB) 和铁处理发菜 sp。在三种不同的 pH 值（4.0、7.0 和 9.0）下研究了生物量（FNB）。在 pH 7.0 时，FNB 记录了两种酚的最高吸附（2.28 mg 4-NP 和 1.51 mg 2,4-DCP g−1）以及最低累积解吸百分比。UNB 和 FNB 对两种酚的吸附最好用准二级动力学来解释。与 UNB 相比，FNB 在所有三个 pH 值下对两种酚都具有显着更高的平衡吸附能力，并且在 pH 4 和 9 下对 4-NP 以及在 pH 4 和 7 下对 2,4-DCP 具有更高的吸附速率常数。变换红外光谱 (FTIR) 分析表明 UNB 的 –OH 和 COO− 基团与 Fe+3 相互作用。4-NP 和 2,4-DCP 在 UNB 上的吸附可能是通过氢键/结构阳离子与酚基桥联，而它们在 FNB 上的吸附似乎是可逆性非常低的络合反应。