CTAB改性海泡石的制备及其对刚果红和双酚A的吸附研究

发布时间：2018-07-13 15:07

【摘要】：染料废水和环境内分泌干扰物质具有毒害性大、难降解等特点,是当前环境问题的焦点,对生态环境和人类健康造成极大的影响。海泡石作为一种廉价的粘土矿物吸附剂,已广泛应用于废水处理,但亲水性使其在有机废水处理中受限。本论文利用CTAB(十六烷基三甲基溴化铵)改性海泡石对刚果红和双酚A进行吸附研究,对目前受染料废水和环境内分泌干扰物质污染的水体治理具有十分重要的意义。(1)利用CTAB对海泡石原土进行有机改性、再进一步热活化处理,制得CTAB用量为0.3~1.0倍海泡石阳离子交换容量(0.3~1.0CEC)的系列改性海泡石(记为H-XCEC-S,其中X表示CTAB用量为海泡石阳离子交换容量的倍数,H和S分别代表活化处理和海泡石原土),制备条件为:改性时间24 h,改性温度为30℃,热活化温度为120℃、热活化时间为2 h。其中,H-0.5CEC-S对刚果红吸附性能最佳,H-0.8CEC-S对双酚A的吸附性能最佳。(2)H-0.5CEC-S对刚果红的最佳吸附条件为:M=1 g/L,p H=7,t=120 min,H-0.5CEC-S和S对刚果红的饱和吸附量分别为649.98 mg/g、88.50 mg/g。二级动力学数学模型和Langmuir等温吸附模型能够更好的描述H-0.5CEC-S对刚果红的吸附,在温度为288K、298K、308K条件下进行拟合,理论饱和吸附量分别为578.03 mg/g、675.67 mg/g、740.74 mg/g,热力学参数分析ΔG0,ΔH0,ΔS0,H-0.5CEC-S对刚果红的吸附行为是自发的吸热过程。(3)H-0.8CEC-S对双酚A的最佳吸附条件为:M=1 g/L,p H=10,t=240 min,H-0.8C-S和S对双酚A的饱和吸附量分别为46.31mg/g、16.79 mg/g。H-0.8CEC-S对双酚A的吸附动力学符合准二级动力学数学模型,吸附热力学符合Langmuir等温吸附模型,在温度为291K、301K、311K条件下进行拟合,理论饱和吸附量分别为52.08 mg/g、46.62 mg/g、40.58 mg/g,热力学参数分析ΔG0,ΔH0,ΔS0,H-0.8CEC-S对双酚A的吸附行为是自发的放热过程。(4)经SEM、p I、BET、TG/DSC、XRD表征分析,CTAB改性海泡石表面变得光滑,形态松散,疏水性增强;H-0.5CEC-S、H-0.8CEC-S的等电点分别由改性前的8.72增大到8.97和9.08,比表面积由25.44 m~2/g分别减小到12.35 m~2/g和8.96 m~2/g;海泡石改性前后的层间距d_((110))=12.07 nm均保持不变,表明CTAB没有插入海泡石层间,只是覆盖在海泡石外表面和孔道内表面,因此吸附作用主要发生在海泡石表面;经吸附前后FT-IR、XPS表征分析,H-0.5CEC-S对刚果红的吸附和H-0.8CEC-S对双酚A的吸附存在配位作用,π-π堆积和离子交换作用。综合表征分析结果,H-0.5CEC-S对刚果红的吸附作用主要为-SO_3~-基团与H-0.5CEC-S表面静电引力作用和Br~-的离子的交换作用、-SO_3~ 和-N=N-基团的氢键作用。H-0.8CEC-S对双酚A的吸附作用主要为Br~-的离子交换作用、还有BPA~-、HBPA~(2-)与H-0.8CEC-S表面静电引力作用、-OH基团的氢键作用。
[Abstract]:Dyestuff wastewater and environmental endocrine disrupting substances are the focus of the current environmental problems because of their high toxicity and difficult degradation. They have a great impact on the ecological environment and human health. Sepiolite, as a cheap clay mineral adsorbent, has been widely used in wastewater treatment, but its hydrophilicity is limited in organic wastewater treatment. In this paper, the adsorption of Congo red and bisphenol A by CTAB (cetyltrimethylammonium bromide) modified sepiolite was studied. It is of great significance to treat the water polluted by dyestuff wastewater and environmental endocrine disrupting substances. (1) using CTAB to modify sepiolite soil organically and reheat it further. A series of modified sepiolite (H-XCEC-S) with CTAB dosage of 0.3n 1.0 times of sepiolite cation exchange capacity (0.3CCEC-S) were prepared, where X indicated that the amount of CTAB was multiple H and S of the cation exchange capacity of sepiolite for activation treatment and sepiolite primordium, respectively. , the preparation conditions are as follows: modification time is 24 h, modification temperature is 30 鈩，

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