摘要
考察了纳米铁的投加量、二硝基甲苯磺酸钠(DNTS)初始浓度、初始pH、纳米铁超声、干燥处理等因素对纳米铁还原TNT红水中DNTS效果的影响。结果表明:考察范围内,纳米铁/DNTS质量比越大,DNTS的去除率越高,单位质量纳米铁去除DNTS总质量越小;当初始pH<10时,去除率受pH影响不大,但准一级反应速率常数随pH上升而接近直线下降,酸性条件下还原更彻底,碱性条件下吸附沉淀作用更明显;干燥处理使纳米铁被部分氧化,还原能力下降;超声有助于促进纳米铁的充分分散和表面氧化层的剥离,提高反应活性。去除率随时间变化曲线表明,2,4-DNT-5-SO3Na(H)比2,4-DNT-3-SO3Na(H)容易被还原。
Batch experiments were conducted in the system to investigate the factors affecting the removal of dinitrotoluene sulfonates(DNTS),including nanoscale zero-valent iron(NZVI) dosage,initial concentration of DNTS,initial pH value of solution and ultrasonication and drying process of NZVI.The removal efficiencies of DNTS increased with the rising of weight ratio of NZVI and DNTS,when the reduction capacity of NZVI was decreasing.When initial pH ranged from 1 to 10,the removal decreased little,however,the pseudo-first-order rate constants decreased almost linearly with initial pH.In addition,DNTS was more likely removed by adsorption and co-precipitation effect than reduction of NZVI at alkaline condition.After undergoing drying process,the reaction activity of prepared NZVI particles decreased by 2/3 compared with fresh ones owing to partly oxidation of NZVI.Ultrasonication was helpful for breaking agglomerate NZVI clusters into small NZVI particles and denuding the Fe0 in the core of the particles and ultimately improving the reactivity.Time-dependent removal of DNTS revealed that 2,4-DNT-5-SO3Na(H) was easier reduced than 2,4-DNT-3-SO3Na(H).
出处
《水资源与水工程学报》
2012年第1期124-128,共5页
Journal of Water Resources and Water Engineering
关键词
纳米铁
二硝基甲苯磺酸钠
TNT红水
影响因素
nanoscale zero-valent iron
dinitrotoluene sulfonates
TNT red water
impact factors
