Data from: Evaluation and mechanism of ammonia nitrogen removal using sediments from a malodorous river

Malodorous rivers are among the major environmental problem of cities in developing countries. In addition to the unpleasant smell, the sediments of such rivers can act as a sink for pollutants. The excessive amount of ammonia nitrogen (NH3−N) in rivers is the main factor that causes the malodor. Therefore, a suitable method is necessary for sediment disposition and NH3−N removal in malodorous rivers. The sediment in a malodorous river (PS) in Beijing, China was selected and modified via calcination (PS-D), Na+ doping (PS-Na), and calcination−Na+ doping (PS-DNa). The NH3−N removal efficiency using the four sediment materials was evaluated, and results indicated that the NH3−N removal efficiency using the modified sediment materials could reach over 60%. PS-DNa achieved the highest NH3−N removal efficiency (90.04%). The kinetics study showed that the pseudo-second-order model could effectively describe the sorption kinetics and that the exterior activated site had the main function of P sorption. The results of the sorption isotherms indicated that the maximum sorption capacities of PS-Na, PS-D, and PS-DNa were 0.343, 0.831, and 1.113 mg g−1, respectively, and a high temperature was favorable to sorption. The calculated thermodynamic parameters suggested that sorption was a feasible or spontaneous (ΔG < 0), entropy-driven (ΔS > 0), and endothermic (ΔH > 0) reaction.

黑臭河流是发展中国家城市面临的主要环境问题之一。除散发令人不适的恶臭外，这类河流的沉积物还可作为污染物的汇。河流中过量的氨氮（ammonia nitrogen, NH3−N）是引发水体黑臭的核心因素。因此，针对黑臭河流的沉积物处置与氨氮去除，亟需开发合适的技术方案。本研究选取中国北京某黑臭河流的沉积物（PS）作为实验原料，分别通过煅烧改性（PS-D）、钠离子掺杂（PS-Na）以及煅烧-钠离子复合掺杂（PS-DNa）三种方式对其进行改性处理。对四种沉积物材料的氨氮去除效能开展了评估，结果显示，改性后的沉积物材料对氨氮的去除率均可达到60%以上，其中PS-DNa的氨氮去除效果最优，去除率可达90.04%。动力学研究表明，准二级动力学模型（pseudo-second-order model）可有效描述该吸附过程的动力学特征，且表层活性位点在磷吸附过程中占据主导作用。吸附等温线实验结果显示，PS-Na、PS-D与PS-DNa的最大吸附容量分别为0.343、0.831及1.113 mg·g⁻¹，且较高的温度对吸附过程具有促进作用。热力学参数计算结果表明，该吸附反应为可行且自发的过程（ΔG < 0）、熵驱动过程（ΔS > 0）且为吸热反应（ΔH > 0）。