湖泊科学   2019, Vol. 31 Issue (5): 1229-1238.  DOI: 10.18307/2019.0506. 0

### 引用本文 [复制中英文]

[复制中文]
LIU Xing, LIU Wenli, CHEN Xing, JIANG Xia, GUO Jifeng, LU Ying, HUANG Wei. Efficiency and mechanism of nutrient removal using modified sediments from a malodorous river. Journal of Lake Sciences, 2019, 31(5): 1229-1238. DOI: 10.18307/2019.0506.
[复制英文]

2018-12-16 收稿
2019-02-27 收修改稿

### 码上扫一扫

(1: 长安大学建筑工程学院, 旱区地下水文与生态效应教育部重点实验室, 西安 710054)
(2: 中国环境科学研究院, 湖泊水污染治理与生态修复技术国家工程实验室, 北京 100012)
(3: 东华大学环境科学与工程学院, 上海 201620)

Efficiency and mechanism of nutrient removal using modified sediments from a malodorous river
LIU Xing1,2 , LIU Wenli2 , CHEN Xing2 , JIANG Xia2 , GUO Jifeng1 , LU Ying2 , HUANG Wei2,3
(1: School of Architecture and Engineering, Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, Chang'an University, Xi'an 710054, P. R. China)
(2: National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing 100012, P. R. China)
(3: College of Environmental Science and Engineering, Donghua University, Shanghai 201620, P. R. China)
Abstract: In order to study the method of sediment resource utilization in the malodorous river, and to evaluate the nutrient removal efficiency using modified sediment and its removal mechanism, the sediment samples (S) from a seriously malodorous river in Beijing were collected in this study. The sediment was modified by oxidation and metal ion-loaded (MS). The nutrient removal efficiency for S and MS was evaluated. The removal mechanism of nutrient was studied through kinetics, equilibrium, and thermodynamic experiments. The results indicated that when the environmental temperature was 35℃, and solid to liquid ratio was 1:50 (g:ml), the nitrogen (initial concentration, 20 mg/L) and phosphorus (initial concentration, 10 mg/L) removal efficiency by using MS was up to 90% and 98%, respectively. The pseudo-second-order model could better describe the sorption kinetics (R2>0.93), and the kinetic and isotherm study illustrated that data from the isotherm experiments were well described by Langmuir isotherm model. The sorption capacity reached 0.891 mg/g for nitrogen and 0.474 mg/g for phosphorus, respectively. The thermodynamic result suggested that enthalpy (ΔH0) and entropy (ΔS0) were positive, and Gibbs energy (ΔG0) was negative during the adsorption experiments. The values of ΔG0 decreased with the increase of temperature. The results showed that MS had the higher nutrient sorption capacity, and the exterior activated site had the main function of phosphorus and nitrogen sorption. The sorption process was a spontaneous or endothermic reaction, and high temperature was in favour of sorption. In addition, the results also indicated that desorption occurred more easily than sorption at the same temperature.
Keywords: Malodorous river    modified    sediments    nutrient    adsorption

1 材料与方法 1.1 样品采集与改性材料的制备

1.2 常规指标测定

1.3 实验设计 1.3.1 效果评估实验

1.3.2 吸附动力学实验

1.3.3 吸附等温及吸附热力学实验

1.4 数据处理

 $Q_{t}=\left(C_{0}-C_{t}\right) \frac{V}{W}$ (1)

 $\eta \%=\frac{\left(C_{0}-C_{t}\right)}{C_{0}} \times 100 \%$ (2)

 $Q_{t}=Q_{\mathrm{e}}\left(1-\mathrm{e}^{-K_{\mathrm{i}} \cdot t}\right)$ (3)

 $\frac{T}{Q_{t}}=\frac{1}{K_{2} \cdot Q_{\mathrm{e}}^{2}}+\frac{t}{Q_{\mathrm{e}}}$ (4)

 $Q_{\mathrm{e}}=\frac{Q_{\mathrm{m}} \cdot K \cdot C_{\mathrm{e}}}{1+K \cdot Q_{\mathrm{m}}}$ (5)
 $Q_{\mathrm{e}}=K_{f} \cdot C_{\mathrm{e}}^{n}$ (6)

 $K_{D}=\frac{C_{0}-C_{\mathrm{e}}}{C_{\mathrm{e}}} \cdot \frac{V}{m}$ (7)
 $\Delta G^{0}=-R \cdot {T}{\rm{ln}}\left(K_{D}\right)$ (8)
 $\ln \left(K_{D}\right)=-\frac{\Delta H^{0}}{R \cdot T}+\frac{\Delta S^{0}}{R}$ (9)

2 结果与讨论 2.1 改性沉积物对磷和氨氮去除效果的评估

 图 1 温度对改性材料氨氮和磷酸盐去除率的影响 (S-P和MS-P分别为S和MS对磷酸盐的去除率，S-N和MS-N分别为S和MS对氨氮的去除率，下同) Fig.1 Effect of temperature on ammonia nitrogen and phosphorus removal efficiency of modified materials (S-P and MS-P for the efficiency of phosphorus using S and MS, respectively; S-N and MS-N for the efficiency of ammonia nitrogen using S and MS, respectively, the same below)

2.2 改性沉积物对氮、磷吸附的动力学研究

 图 2 不同温度下两种材料对磷和氨氮的吸附动力学拟合曲线 Fig.2 Adsorption kinetics curves of phosphorus and ammonia nitrogen for two materials at different temperatures

2.3 改性沉积物氮、磷吸附等温线分析

 图 3 两种材料在不同温度下对磷和氨氮的吸附等温曲线 Fig.3 Adsorption isotherms of phosphorus and ammonia nitrogen for two materials at different temperatures

2.4 改性沉积物氮、磷吸附的热力学研究

 图 4 两种材料在不同初始浓度下吸附磷的热力学曲线 Fig.4 Thermodynamic curves of phosphorus adsorption by two materials at different initial concentrations

3 结论

1) 经过改性的材料对氨氮的去除率达到90 %以上，对磷的去除率达98 %以上.

2) 改性材料对磷的吸附量可达0.474 mg/g，其吸附量已高于一般的磷吸附材料，在磷的去除上应用前景较大.

3) 改性材料对氨氮的吸附量可达0.891 mg/g，其吸附量在一定程度上虽低于市面上氮吸附剂，但综合材料对磷的吸附量及黑臭河道沉积物资源化效率、经济成本等因素，该材料在氨氮和磷的去除上也具有一定的应用前景.

4) 通过对改性材料氮、磷去除机制的研究，发现该改性材料对氮、磷的去除效果受温度影响，较高的温度更有利于材料对氮、磷的去除.这也表明在气候温度较高、氮磷含量较高的水体更适合采用该改性材料去除氮、磷.

5) 本研究中的改性沉积物可以被认为是在污染水体净化领域的高效去除营养盐材料，同时本研究结果为黑臭河道沉积物资源化途径和水体中氮、磷削减提供了一定的理论依据.

4 参考文献