填料投资是湿地总造价中所占比例最大的部分，约占总造价的 40~50 %。 为大幅度降低潜流人工湿地的建设费用，以城市污水处理厂初沉池出水为人工 湿地的进水，对细沙作为极浅型潜流人工湿地填料的可行性进行了现场试验研 究。主要探讨了不同季节、不同填料深度和不同湿地植物与处理效率之间的关 系，以及气候条件和现场维护管理对系统湿地去除效果的影响。实验组为填料 床深 0.1m 的极浅型潜流人工湿地,种植植物分别为高羊茅、黑麦草、狗牙根、 芦苇和香蒲；对照组为填料床深 0.1m 无植物对照和填料床深 0.6m 的潜流人工 湿地，种植植物分别为狗牙根和香蒲。为避免幼苗期植物根系尚不发达阶段可 能发生的堵塞，向细沙中添加小麦秸秆。0.1m 和 0.6m 湿地理论水力停留时间相 同，运行水深分别为 0.08m 和 0.58m，采用间歇进水方式，0.1m 湿地日进水量 均为 0.03 m 3 /d，分 3 次进水，0.6m 湿地日进水量均为 0.22 m 3 /d，分 8 次进水。 系统共运行近六个月。研究结果表明， （1）0.1m 各湿地在非冬季对污染物的处理效率稳定，各湿地非冬季出水 SCOD、TN 、TP、氨氮平均去除率均分别高于 65.3%、82.8%、95.0%、93.7%， 与非冬季相比冬季处理效率虽有显著性差异和下降，但去除效果依然良好，表现 出极浅型潜流湿地良好的处理效果。这与以往研究中以碎石、粗砂作为极浅型潜 流湿地填料的现象吻合。表明极浅型潜流湿地冬季对污染物去除效果良好这一特 性与填料的粒径无关，而细沙较早期研究中以碎石和粗砂等大粒径天然材料作为 湿地填料成本下降幅度达到 50%以上，故，细沙作为极浅型潜流湿地的填料可 行。 （2）人工湿地中填料床的深度不仅与容积负荷和水力停留时间等相关，而 且还直接影响着系统对水中污染物的去除效率。研究表明，0.1m 湿地出水溶解氧西安建筑科技大学硕士学位报告 浓度显著高于 0.6m 湿地，有效地解决了传统大深度湿地中溶解氧浓度不足以及 厌氧区域过大的弊端，提升了系统对污染物质的去除效率。即便是无植物的对照 组出水 DO 浓度也显著且稳定地高于进水 DO 浓度，表明即便出现了填料孔隙率 下降的现象，因细沙的厚度仅为 0.1m，大气复氧作用仍然持续强劲。 （3）高羊茅、黑麦草冬季仍表现出了较强的活力，多次分蘖，可减少换种 的麻烦，节省管理维护的费用。高羊茅和黑麦草湿地出水 DO 显著高于其他 0.1m 湿地（P<0.05），TN、TP 和氨氮平均去除率达到 78.7%、85.0%和 88.9%，均稳 定高于其他 0.1m 湿地，更适合作为北方寒冷地区湿地植物。 （4）植物对湿地去除污染物发挥着至关重要的作用，0.1m 各湿地出水主要 污染物的去除效果均显著优于 0.1m 对照组。运行 3 个月时 0.1m 各湿地填料空隙 率提高 7%-25%，0.1m 对照组填料空隙率下降 20%。 （5）在植物幼苗期，向细沙中添加小麦秸秆导致湿地出水的 SCOD 和浊度 较高，运行第 76 天后无显著影响（P>0.05），向细沙中添加的小麦秸秆还可作为 植物碳源显著提高湿地的脱氮效率（P=0.012<0.05）。 关键字，极浅型潜流人工湿地 城市污水 细沙 填料 报告类型，应用研究西安建筑科技大学硕士学位报告 Feasibility Study of Using Fine Sand as the Substrate of Extremely Shallow Subsurface Constructed Wetland Major: Municipal Engineering Graduate: Wang Xinwei Instructor: Prof. Ren Yongxiang Abstract The substrate is the largest part in construction investment of subsurface flow constructed wetlands (SSFCW)，it accounts for about 40 to 50% of the total investment. To significantly reduce the construction cost，a pilot scale study was employed to investigate the feasibility of using fine sand as the substrate of extremely shallow SSFCW, in which the influent was the effluent from a primary sedimentation tank in a municipal wastewater treatment plant in Xi’an. This study investigated the relationship among the different seasons, different fillers depth, different wetland plants and processing efficiency,and investigated climatic conditions and On-site maintenance and management impacted on the treatment effect. The substrate depth of experimental group was 0.1m ， Festuca arundinacea, Lolium perenne, Cynodon dactylon, Phragmites australis and Typha orientalis Presl were planted.The control group was substrate 0.1m deep SSFCW without packing plant control and substrate 0.6m deep SSFCW，and Cynodon dactylon and Typha orientalis Presl were planted. During the seedling stage, to avoid congestion, add wheat straw into fine sand. The theory HRT of all wetlands is 6d，running water depth were 0.08m and 0.58m，the water loading of experimental group wetlands is 0.03m 3 /d, intermittent water three times a day，and the water loading of 0.6m deep SSFCW is 0.22 m 3 /d，intermittent water eight times a day. The system running for six months.The main results and conclusions are shown as follows: (1) In non-winter, the average removal efficiencies for SCOD, NH 4 + -N, TN and TP were higher than 65.2%, 93.7%, 82.8% and 95.0%,compared with the non-winter efficiency than in winter, although significant differences and fall, but the removal is still good, showing extremely shallow SSFCW good treatment effect. This phenomenon is consistent with gravel and coarse sand as the substrate of extremely shallow SSFCW.西安建筑科技大学硕士学位报告 Though 0.1m deep and 0.6m deep wetlands design theory HRT is same , in the running process 0.6m deep wetlands treatment efficiency decreased, 0.1m deep wetlands treatment efficiency is significantly higher than 0.6m deep wetlands. (2) The depth of substrate was closely related with the hydraulic loading rate and hydraulic retention time, and directly affects the removal efficiency of pollutants in CWs. Studies have shown that ， the DO of 0.1m deep SSFCW effluent was significantly higher than 0.6m deep SSFCW, effectively solves the traditional large depth of SSFCW and lack of DO in the anaerobic area is too large , enhance the efficiency of the system to remove pollutants. Even 0.1m deep control group without the plant effluent DO was also significantly higher stably than the influent DO, suggesting that even substrate porosity decreased because of the thickness of the fine sand is only 0.1m, reaeration role continued strong. (3) In winter Festuca arundinacea and Lolium perenne still showed strong vitality, and multiple tiller, this can reduce the hassle for species, saving the cost of management and maintenance.The 0.1m deep wetland planting Festuca arundinacea and Lolium perenne effluent DO 0.1m was significantly higher than other 0.1m deep wetlands (P <0.05), TN, TP and NH 4 + -N average removal rate reached 78.7% , 85.0% and 88.9% , and stably higher than other 0.1m deep wetlands , so Festuca arundinacea and Lolium perenne are more suitable as wetland plants in cold northern areas. (4) Wetland plants plays a crucial role in removing pollutants, each 0.1m deep wetland effluent pollutant removal efficiency was significantly better than the 0.1m deep control group. After system running about three months the substrate void ratio of 0.1m deep wetlands increased by 7% -25%, the 0.1m deep control group decreased by 20%. (5) During the seedling stage, the addition of wheat straw in the substrate resulted in the increasing of SCOD and turbidity of effluent, while it was not significant influence by 76 d (P>0.05). The wheat straw adding to fine sand can significantly improve the efficiency of denitrification (P=0.012<0.05). Key words: extremely shallow constructed wetland ； municipal wastewater ； fine sand；substrate Paper type: Application research西安建筑科技大学硕士学位报告 I 目录 1 绪论.....................................................................................................................1 1.1 研究背景 ..................................................................................................1 1.1.1 人工湿地简介..................................................................................1 1.1.2 人工湿地分类、净化机理..............................................................2 1.1.3 人工湿地植物的作用......................................................................4 1.1.4 植物碳源对脱氮的影响 .................................................................5 1.1.5 人工湿地在北方冬季寒冷地区的越冬问题..................................5 1.1.6 人工湿地国内外研究动态..............................................................7 1.2 课题来源、研究目的和意义 ..................................................................8 1.2.1 课题来源..........................................................................................8 1.2.2 研究目的和意义..............