环保型防扩散剂在绞吸过程中的防扩散性能研究

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15mg/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1h后上覆水体浊度达到最低值10.23NTU,COD达到最低值12.0mg/L,相对未添加防扩散剂的上覆水体浊度、COD下降率分别为83.6%、89.1%,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19.250μm,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。

Study on the anti-diffusion performance of environmentally-friendly anti-diffusion agents in the cutter-suction process

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.