Polowczyk Izabela, Cyganowski Piotr, Ulatowska Justyna, Sawiński Wojciech, Bastrzyk Anna
1Division of Chemical Engineering, Wroclaw University of Science and Technology, Wybrzeże S. Wyspiańskiego 27, 50-370 Wrocław, Poland.
2Division of Polymer and Carbonaceous Materials, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże S. Wyspiańskiego 27, 50-370 Wrocław, Poland.
Water Air Soil Pollut. 2018;229(6):203. doi: 10.1007/s11270-018-3866-2. Epub 2018 Jun 8.
Removal of arsenic from water reservoirs is the issue of great concern in many places around the globe. As adsorption is one of the most efficient techniques for treatment of As-containing media, thus the present study concerns application of iron oxides-hydroxides (akaganeite) as adsorbents for removal of this harmful metal from aqueous solution. Two types of akaganeite were tested: synthetic one (A) and the same modified using hexadecyltrimethylammonium bromide (A). Removal of As was tested in batch studies in function of pH, adsorbent dosage, contact time, and initial arsenic concentration. The adsorption isotherms obey Langmuir mathematical model. Adsorption kinetics complies with pseudo-second-order kinetic model, and the constant rates were defined as 2.07 × 10and 0.92 × 10 g mg min for the samples (A) and (A), respectively. The difference was caused by significant decrease in adsorption rate in initial state of the process carried out for the sample A. The maximum adsorption capacity achieved for (A) and (A) akaganeite taken from Langmuir isotherm was 148.7 and 170.9 mg g, respectively. The results suggest that iron oxides-hydroxides can be used for As removal from aqueous solutions.
从水库中去除砷是全球许多地方极为关注的问题。由于吸附是处理含砷介质最有效的技术之一，因此本研究关注铁氧化物 - 氢氧化物（针铁矿）作为吸附剂从水溶液中去除这种有害金属的应用。测试了两种类型的针铁矿：合成针铁矿（A）和用十六烷基三甲基溴化铵改性的针铁矿（A）。在批量研究中测试了砷的去除情况，该过程是pH、吸附剂用量、接触时间和初始砷浓度的函数。吸附等温线符合朗缪尔数学模型。吸附动力学符合准二级动力学模型，样品（A）和（A）的速率常数分别定义为2.07×10和0.92×10 g mg min。差异是由样品A在该过程初始状态下吸附速率的显著降低引起的。从朗缪尔等温线得出的（A）和（A）针铁矿的最大吸附容量分别为148.7和170.9 mg g。结果表明，铁氧化物 - 氢氧化物可用于从水溶液中去除砷。
