共查询到19条相似文献,搜索用时 59 毫秒
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为提高膨润土对染料的吸附性能,制备了有机酸改性膨润土-乙酸膨润土(AAB).对AAB 进行了N2-BET、FTIR 和XRD 表征分析,同时考察了影响乙酸膨润土(AAB)去除孔雀石绿(MG)的主要因素,并进行了吸附 动力学和吸附等温模型研究。研究结果表明,乙酸分子已成功负载在天然膨润土(RB)上,AAB 的比表面积为 45m2/g;层间距为1.721nm;在实验条件下,用0.4g/L 的吸附剂处理300mg/L 的MG,MG 的脱色率达到99%; pH 值为1~12 时,AAB 对MG 的脱色率均达到97%以上;低浓度的十二烷基苯磺酸钠(SDBS)能提高AAB 对MG 的去除率,而加入十六烷基三甲基溴化铵(CTAB)会产生很强的抑制作用;AAB 对MG 的吸附符合 Langmuir 模型,Langmuir 吸附容量高达1250mg/g;MG 在AAB 上的吸附先是一个快速吸附阶段,然后逐渐到 达吸附平衡,符合准二级动力学模型。总之,AAB 环保无毒,在MG 去除方面具有用量低、适应pH 值范围广、吸附容量大和吸附快速的优势。 相似文献
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《应用化工》2022,(5):1204-1210
研究吸附时间、pH、污泥投加量和温度等对厌氧颗粒污泥吸附水中孔雀石绿(MG)的影响。结果表明,在MG初始浓度为50 mg/L和60 mg/L时,平衡时间为30 min,在MG初始浓度为70 mg/L和80 mg/L时,平衡时间为50 min;在MG初始浓度为100 mg/L时,厌氧颗粒污泥吸附水中MG的最佳pH为6~8,最佳投加量为2.4 g/L(干重);厌氧颗粒污泥对MG的吸附能力随温度增加而增加,在40℃时最大吸附容量为137.696 mg/g。厌氧颗粒污泥对水中MG的吸附可以采用Redlich-Peterson模型进行描述,表明厌氧颗粒污泥对MG的吸附并非理想的单层吸附,而是物理吸附和生物化学吸附共同作用的结果;MG与厌氧颗粒污泥作用的速率取决于化学吸附,其中液膜内扩散速率是限制厌氧颗粒污泥对MG吸附的主要因素。 相似文献
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Mehmet A. Oturan Elodie Guivarch Nihal Oturan Ignasi Sirs 《Applied catalysis. B, Environmental》2008,82(3-4):244-254
A very detailed scheme for the Fe3+-catalyzed electro-Fenton mineralization of malachite green as a model triarylmethane dye is presented. Bulk electrolyses of 250-mL aqueous solutions of 0.5 mM malachite green with 0.2 mM Fe3+ as catalyst have been carried out at room temperature and pH 3.0 under constant current in an undivided cell equipped with a graphite-felt cathode and a Pt anode to assess the performance of the electro-Fenton system. In situ electrogeneration of Fe2+ and H2O2 from quick cathodic reduction of Fe3+ and dissolved O2 (from bubbled compressed air), respectively, allows the formation of the very oxidizing species hydroxyl radical (OH) in the medium from Fenton's reaction. A pseudo-first-order decay kinetics with an apparent rate constant of k1,MG = 0.244 min−1 was obtained for total destruction of malachite green by action of OH at 200 mA, requiring 22 min for total decoloration of the solution. In the same experimental conditions, overall mineralization was reached at 540 min. Up to 15 aromatic and short-chain carboxylic acid intermediates were identified along the treatment. The evolution of current efficiency was calculated from the chemical oxygen demand (COD) removal. Based on the time course of most of the by-products and the identification of inorganic ions released, some plausible mineralization pathways are proposed and thoroughly discussed. It has been found that the electro-Fenton degradation of malachite green proceeds via parallel pathways, all of them involving primary splitting of the triaryl structure initiated by attack of OH on the central carbon, thus yielding two different N-dimethylated benzophenones. Successive cleavage of the aromatic intermediates generates oxalic acid as the ultimate short-chain carboxylic acid, whereas N-demethylation of some of them produces formic acid as well. Oxalic acid and its Fe2+ complexes, as well as formic acid, can be slowly but totally mineralized by OH. 相似文献
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在稀Hel介质中,Ⅰ-可催化KIO4氧化孔雀绿的褪色反应,且褪色程度与Ⅰ-浓度成正比,由此建立了测定痕量Ⅰ-的新方法,确定了最佳反应条件.测定碘的线性范围是0.5~5.0mg·L-1;检出限为0.3mg·L-1.方法简便、准确,用于食盐中碘的测定,结果满意. 相似文献
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酶解-溶剂提取银杏叶活性成分工艺条件 总被引:5,自引:0,他引:5
研究了酶法与溶剂提取相结合提取银杏叶中活性成分银杏黄酮的工艺条件。通过正交试验找出纤维素酶法及溶剂提取的最佳工艺条件,通过紫外分光光度检测及紫外扫描进行产物分析。纤维素酶的最佳提取工艺条件为纤维素酶浓度40 U/mL,酶解pH值4.8,酶解温度55℃,酶解时间90 m in。溶剂提取的最优工艺条件为无水乙醇∶粗提液(体积比)=1∶10,石油醚∶粗提液(体积比)=3∶1,乙酸乙酯∶粗提液(体积比)=2∶1。酶解-溶剂提取是一种安全高效的提取方法。 相似文献
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采用沉淀法将CdS与锌铁层状双金属氢氧化物(Zn-Fe LDH)复合,高温煅烧后得到CdS/ZnO-ZnFe2O4复合材料(CdS/Zn-Fe LDO)。利用XRD、SEM、UV-vis DRS及PL对复合材料的结构、形貌、光学性能进行了表征。研究了该复合材料在可见光下对孔雀石绿的光降解,结果表明:CdS/Zn-Fe LDO复合材料对孔雀石绿的光催化降解能力高于CdS或Zn-Fe LDO,其中,m(CdS) : m(Zn-Fe LDH)=1 : 1配比制备的CdS/Zn-Fe LDO(1:1)光催化活性最大。光照20 min,20 mg CdS/Zn-Fe LDO(1:1)对20 mg/L孔雀石绿的光降解率为96.6%。此外,该复合材料还可降解罗丹明B、亚甲基蓝、甲基橙、结晶紫等染料且光降解反应符合一级反应动力学。 相似文献