【作者】 祝荣华；

【导师】 张渊明；

【作者基本信息】 暨南大学 ， 物理化学， 2011， 硕士

【摘要】 随着工农业的发展和人类生活的改善,大量含磷污水的过度排放,导致了水体富营养化。因而,需要寻求一种简单有效且经济廉价的除磷方法。吸附法除磷近年来受到广泛的关注,许多天然或人工合成材料被用做吸附剂除磷。为了降低吸附除磷技术的成本,提高除磷效果,寻找低价高效的吸附剂已经成为吸附除磷领域的研究热点。本文用FeCl3对红壤进行改性,将得到的改性红壤作为吸附剂用于对磷的吸附去除研究。实验结果表明,改性红壤对磷酸根有显著的吸附作用,35℃时的最大吸附容量为428.4 mg/g。整个吸附过程是一个自发的放热过程,符合Freundlich等温线模型和准二级反应动力学。溶液pH值和温度对磷酸根在改性红壤上的吸附有明显影响,随着pH和温度的升高,改性红壤的吸附容量降低,但离子强度和几种共存阴离子对吸附没有明显影响。对吸附剂的解吸和重复吸附实验研究表明,1 M NaOH溶液对吸附后改性红壤的洗脱效果最好,磷的解吸率达到98%。在重复使用4次之后,吸附剂对磷仍然有很好的吸附性能。对磷酸根吸附机理的研究表明,静电吸引和表面络合作用是改性红壤吸附磷酸根的主要机理。更多还原

【Abstract】 With the development of industry and agriculture and the improvement of people’s life, the excessive discharge of sewage containing phosphate causes eutrophication. Thus, it’s necessary to pursue a simple, efficient and economic method for phosphorus removal.Adsorption method for phosphate removal has drawn considerable interest in recent years. Many natural and artificial materials are used as adsorbents. In order to reduce the cost and improve the efficiency, pursuing an economic and efficient adsorbent has been a hot area in the field of phosphorus removal.In this dissertation, red earth was modified with FeCl3 and the resulted modified red earth were used as adsorbent to remove phosphate. The experimental results showed that the modified red earth exhibited great efficiency and the maximum adsorption capacity was 428.4 mg/g at 35℃, The adsorption process was spontaneous and exothermic, fit Freundlich isotherm model and followed a pseudo-second-order kinetic model. The adsorption was strongly dependent on pH and temperature. As pH and the temperature increased, the adsorption capacities of the modified red earth reduced. But ion strength and coexisting ions had no obvious effect on the adsorption. The desorption studies revealed that modified red earth could be best eluted by 1 M NaOH solution and the desorption efficiency reached 98%. The adsorbent still showed a great efficiency after 4 cycles. The adsorption mechanism was mainly attributed to electrostatic interactions and surface complexations.更多还原