针对疏浚工程中底泥扩散问题, 设计了一套绞吸试验装置, 通过 CFD 模型预测出底泥的扩散分布, 在绞吸过 程中投加环保型防扩散剂 CPAM、PSF 及复配 CPAM/ PSF, 通过对底泥的沉降速率、上覆水体浊度及 COD、粒径以 及 SEM 形貌变化等来探究防扩散剂在绞吸过程中的防扩散效果。结果表明: 在投加的防扩散剂中 CPAM 对底泥 的防扩散效果最佳, 当 CPAM 的投加量为 15 mg / L 时, 相对最终的底泥沉降率来说, 95% 泥样基本是在瞬间沉降, 且沉降 1 h 后上覆水体浊度达到最低值 101 23 NTU, COD 达到最低值 121 0 mg / L, 相对未添加防扩散剂的上覆水 体浊度、COD 下降率分别为 831 6% 、891 1% , 从其沉降泥样 SEM 图片中也可以看出其底泥颗粒粒径增大最为明显, 中值粒径达到 191 250 Lm, 相对未添加防扩散剂的底泥颗粒粒径增长率为 117%, 在底泥的防扩散上表现出良好效果。

In order to solve the pr oblem of sediment diffusion in dr edg ing pr ojects, we desig ned a cutter suctio n ex periment de2 v ice. The diffusion dist ribution o f sediment was pr edicted by CFD model. CPAM, PSF and CPAM/ PSF w ere added during the cutter suctio n pro cess. We explo red the anti- diffusion effect of anti2diffusion ag ents in cutter suctio n process in terms of the sediment set tling rate, tur bidity o f overly ing w ater, COD, particle size, and SEM mo rpholog y chang es. T he results show ed t hat CPAM had the best effect on preventing sediment diffusio n. When CPAM dosage w as 15 mg/ L, 95% of the mud sam ples basi2 cally sett led in an instant relative to the final sediment settling rat e; after 1 ho ur of sett ling , the turbidity o f the ov erlying w ater reached the low est value o f 101 23 NTU and COD reached the lowest value o f 121 0 mg/ L, w hich w ere respect ively 831 6% and 891 1% low er t han t he turbidity and COD of t he overly ing wat er w itho ut anti2diffusion ag ent. Fr om the SEM pictures o f the sed2 iment samples, it can be seen that t he sediment particle size increased the most obvio usly, with the median particle size reaching 191 250 Lm. which w as 117% higher than that of the sediment w ithout the anti2diffusion agent. T he ag ent showed go od effects in pr event ing the spr ead o f sediment.

中交天航环保工程有限公司基金( 1700030003; 1700030031)