矿物对黑臭水体氮磷释放抑制及流场仿真模拟

Inhibition of nitrogen and phosphorus release in black and odorous waterbodies by minerals and simulation of flow fields

利用片状闽东南麦饭石作为覆盖材料,对受污染底泥进行覆盖并研究其对氮磷缓释的影响,探究不同覆盖量与流速对底泥氮磷污染物的抑制效果.结果表明,当麦饭石的覆盖量达到8 kg·m-2以上,流速不超过0.1 m·s-1时,对底泥原位覆盖488 h后上覆水满足Ⅳ类水质标准.研究结果表明麦饭石对氮和磷的吸附过程分别符合Langmuir和Freundlich等温模型;吸附类型分别为单分子层化学吸附和多分子层物理吸附.最后根据污染物的扩散迁移规律建立一种流场-浓度场耦合模型,模型预测的氮磷释放量与实验数据的平均相对误差分别为0.235和0.010,表明该模型对氮磷释放的计算与预测是准确可靠的.

Flaky Mindongnan medicinal stone was used to study its inhibition effect on nitrogen and phosphorus from contaminated sediment.The results showed that the medicinal stone was able to inhibit the release of endogenous nitrogen and phosphorus significantly from the black and odorous water body.When the coverage of medicinal stone reached more than 8 kg·m-2 and the flow rate did not exceed 0.1 m·s-1,the overlying water was able to fulfill the Class IV water quality standard upon 488 h of in situ covering of the sediment.The results showed that the adsorption process of medicinal stone on nitrogen and phosphorus conformed to Langmuir,Freundlich isotherm isothermal model,and the adsorption type was single-layer chemical,physical adsorption with multi molecular layer,respectively.Finally,a flow field concentration field coupling model was established based on the diffusion and migration law of pollutants.The average relative errors between the predicted nitrogen and phosphorus release amount of the model and the experimental data were 0.235 and 0.010,respectively.This indicates that the model is accurate and reliable in calculating and predicting nitrogen and phosphorus release.