Analysis of purification efficiency of pollutants in farmland runoff by the ecological ditch in winter and spring
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摘要:
为有效提高冬春季沟渠的净化效率，在原有土质沟渠中增设耐寒植物黑麦草浮毯与填料透水坝构建生态沟渠，分析生态沟渠对农田径流中主要污染物的削减率，对比沿程不同处理段对污染物的净化效果，估算植物吸收对于污染通量降低总量的贡献。结果显示：在冬春季节，生态沟渠对总氮（TN）、硝氮（${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$）、总磷（TP）、化学需氧量（COD）和悬浮物（SS）的总削减率均值分别为29.06%、54.93%、20.76%、54.08%和49.85%。透水坝段的TN和${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$沿程削减率最高；植物浮毯+透水坝段的TP和COD沿程削减率最高；植物浮毯段的SS沿程削减率最高，其对${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$、TP和COD也有较好的净化效果。在降水量达到10 mm以上的9 d内，TN和TP的污染通量降低总量分别为11.43和0.27 kg；黑麦草吸收的氮、磷量分别约占污染通量降低总量的20.6%和55.6%。大雪融化后气温降至0 ℃以下，可能引起土壤冻融作用，雪水径流中的氮、磷浓度显著升高，此时生态沟渠对径流中氮、磷的净化效果不明显，可利用周边河塘暂存雪水径流，后续结合生态措施对污染物实施强化处理。
Abstract:To improve the purification efficiency of ditches in winter and spring, the ecological ditch was constructed by adding floating blankets with the cold-tolerant plant (Lolium perenne L.) and permeable dams with adsorption filler in the original soil ditch. The removal rates of main pollutants in farmland runoff by the ecological ditch were analyzed, the purification efficiencies of pollutants in different treatment segments were compared and the contributions of plant absorption to the total pollutant flux reduction were estimated. The results showed that the average values of the total removal rates of total nitrogen (TN), nitrate nitrogen (${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$), total phosphorus (TP), chemical oxygen demand (COD) and suspended solids (SS) were 29.06%, 54.93%, 20.76%, 54.08% and 49.85%, respectively. The removal rates of TN and ${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$ were highest in the permeable dam section of the ecological ditch; the removal rates of TP and COD were highest in the permeable dam section combined with floating blankets; the removal rate of SS was highest in the floating blankets section, and the purification efficiencies of ${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$, TP and COD were also better in the floating blankets section. In the nine days with more than 10 mm of rainfall during the experiment, the total reduction amounts of pollutant flux of TN and TP were 11.43 and 0.27 kg, respectively. The nitrogen and phosphorus amounts absorbed by Lolium perenne L. accounted for 20.6% and 55.6% of the total reduction amount of pollution flux of TN and TP, respectively. When the temperature dropped below 0 ℃ after the melting of heavy snow, the concentrations of nitrogen and phosphorus in snow-water runoff increased significantly, which might be due to soil freezing and thawing. Meanwhile, as the purification efficiencies of nitrogen and phosphorus in snow runoff by ecological ditch were not significant, nearby ponds and rivers could be utilized as temporary storage of the runoff, and further enhanced treatment of pollutants could be implemented in combination with ecological measures.
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Key words:
- winter and spring /
- ecological ditch /
- farmland runoff /
- nitrogen /
- phosphorus
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图 1 生态沟渠设置及采样点位分布示意
Figure 1. Setting of the ecological ditch and distribution of the sampling sites
图 2 生态沟渠处理设施布置俯视图及透水坝布设断面
注：图中数字单位为mm。
Figure 2. Vertical view of different treatments in the ecological ditch and sectional view of the permeable dam
图 3 生态沟渠进出水口TN和${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$浓度变化及总削减率
注：PR-U为PR段前端采样点，代表生态沟渠进水口；EP-D为EP段末端采样点，代表生态沟渠出水口；Rt为总削减率。全文同。
Figure 3. Variations of TN and ${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$ concentrations at inlet and outlet and total removal rates of the ecological ditch
图 4 生态沟渠进出水口TP和$ \mathrm{PO}_4^{3-}\text{-}\mathrm{P} $浓度变化及总削减率
Figure 4. Variations of TP and ${\mathrm{PO}}_ 4^{3-}{\text{-}}{\mathrm{P}} $ concentrations at inlet and outlet and total removal rates of the ecological ditch
图 5 生态沟渠进出口COD和SS浓度变化及总削减率
Figure 5. Variations of COD and SS concentrations at inlet and outlet and total removal rates of the ecological ditch
表 1 试验期间天气、降水量、气温与沟渠内水温、pH及DO
Table 1. Weather, rainfall, air temperature and water temperature, pH and DO in the ecological ditch during the experiment
采样时间（月-日） 天气 降水量/mm 气温/℃ 水温/℃ pH DO 浓度/(mg/L) PR段 PD段 EC段 EP段 PR段 PD段 EC段 EP段 01-27 雨夹雪 10.5 1~4 5.14 8.39 8.92 8.39 8.06 9.67 10.48 10.75 11.05 02-08 雨夹雪 1.0 2~5 6.94 8.31 8.26 8.19 8.09 12.76 12.57 12.91 13.66 02-24 多云 0~10 13.51 8.38 8.15 7.92 7.68 12.11 12.82 13.64 13.33 03-02 多云转晴 6~17 17.51 8.19 8.11 8.10 8.07 11.35 10.14 11.94 11.08 03-17 大雨 40.8 6~9 13.70 7.03 7.26 7.25 7.14 10.43 10.56 11.44 10.73 03-23 小雨 0.2 5~14 16.63 8.54 8.25 8.23 8.19 10.21 11.44 11.16 11.38 04-02 多云转晴 5~17 21.20 8.20 8.54 8.60 8.40 13.02 12.85 13.09 12.44 04-14 多云转晴 12~18 19.10 8.67 8.50 8.65 8.25 12.49 11.30 12.79 11.20 04-29 中雨 10.7 11~15 18.39 8.05 8.13 7.67 7.43 7.79 7.34 8.63 5.95 注：水温数据为沟渠所有采样点的均值，pH和DO浓度数据为沟渠各处理段3个采样点的均值。 
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表 2 生态沟渠各处理段的污染物进水平均浓度与沿程削减率
Table 2. Inlet average concentrations and removal rates of major contaminants of different treatment segments in the ecological ditch
处理段 TN ${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$ TP COD SS 进水平均浓度/
（mg/L）削减率/% 进水平均浓度/
（mg/L）削减率/% 进水平均浓度/
（mg/L）削减率 进水平均浓度/
（mg/L）削减率/% 进水平均浓度/
（mg/L）削减率/% PR段 9.63 7.06 3.44 17.96 1.45 0.00 31.35 4.38 38.53 15.99 PD段 8.74 9.61 2.68 28.77 1.48 0.53 24.12 7.88 38.67 21.26 EC段 7.70 3.83 1.81 23.16 1.46 1.43 25.59 19.62 27.67 34.27 EP段 7.70 2.97 1.62 1.95 1.49 7.23 18.90 21.99 22.37 23.18
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表 3 生态沟渠进出水口主要污染物的污染通量
Table 3. Pollutant flux of major contaminants at inlet and outlet of the ecological ditch
kg/d 采样点 TN ${\mathrm{NO}}_ 3^- $ TP ${\mathrm{PO}}_ 4^{3- }$ COD SS PR-U 5.69 2.03 0.85 0.02 18.52 22.77 EP-D 4.42 0.94 0.82 0.01 8.92 10.15 降低值 1.27 1.09 0.03 0.01 9.60 12.62
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表 4 生态沟渠中植物吸收的氮、磷总量
Table 4. Amount of nitrogen and phosphorus absorbed by the plants in the ecological ditch
处理段 单位面积
鲜质量/（kg/m2）单位面积
干质量/（kg/m2）干物质
氮含量/%单位面积
氮含量/（g/m2）吸收氮总量/kg 干物质
磷含量/%单位面积
磷含量/（g/m2）吸收磷总量/kg EC段 5.25±0.12 0.95 3.42±0.21 32.32 1.16 0.20±0.03 1.89 0.07 EP段 5.16±0.09 0.98 3.39±0.11 33.24 1.20 0.22±0.05 2.16 0.08 合计 2.36 0.15
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[1] 王迪, 李红芳, 刘锋, 等. 亚热带农区生态沟渠对农业径流中氮素迁移拦截效应研究[J]. 环境科学,2016,37(5):1717-1723.WANG D, LI H F, LIU F, et al. Interception effect of ecological ditch on nitrogen transport in agricultural runoff in subtropical China[J]. Environmental Science,2016,37(5):1717-1723. [2] 彭嘉玉, 吴越, 侯泽英, 等. 洱海西部灌排沟渠水质特征及土地利用的影响[J]. 环境工程技术学报,2022,12(3):675-682.PENG J Y, WU Y, HOU Z Y, et al. Water quality characteristics of irrigation and drainage ditches in western Erhai Lake Basin and the effect of land uses[J]. Journal of Environmental Engineering Technology,2022,12(3):675-682. [3] 于会彬, 席北斗, 郭旭晶, 等. 降水对农田排水沟渠中氮磷流失的影响[J]. 环境科学研究,2009,22(4):409-414.YU H B, XI B D, GUO X J, et al. Effect of rainfall runoff on nitrogen and phosphorus loss in farming drainage ditch[J]. Research of Environmental Sciences,2009,22(4):409-414. [4] 黄国鲜, 聂玉玺, 张清寰, 等. 流域农业面源污染迁移过程与模型研究进展[J]. 环境工程技术学报,2023,13(4):1364-1372.HUANG G X, NIE Y X, ZHANG Q H, et al. Research progress of agricultural non-point source pollution migration process and model in basins[J]. Journal of Environmental Engineering Technology,2023,13(4):1364-1372. [5] 刘福兴, 陈桂发, 付子轼, 等. 不同构造生态沟渠的农田面源污染物处理能力及实际应用效果[J]. 生态与农村环境学报,2019,35(6):787-794.LIU F X, CHEN G F, FU Z S, et al. Comparison on effects of practical application of ecological ditches with different construction in treating agricultural non-point pollutants[J]. Journal of Ecology and Rural Environment,2019,35(6):787-794. [6] 翟丽华, 刘鸿亮, 席北斗, 等. 沟渠系统氮、磷输出特征研究[J]. 环境科学研究,2008,21(2):35-39.ZHAI L H, LIU H L, XI B D, et al. Study on the transportation and transformation of N and P in headwater ditches[J]. Research of Environmental Sciences,2008,21(2):35-39. [7] 王晓玲, 乔斌, 李松敏, 等. 生态沟渠对水稻不同生长期降雨径流氮磷的拦截效应研究[J]. 水利学报,2015,46(12):1406-1413.WANG X L, QIAO B, LI S M, et al. Studies on the interception effects of ecological ditch on nitrogen and phosphorus in the rainfall runoff of different rice growth period[J]. Journal of Hydraulic Engineering,2015,46(12):1406-1413. [8] 陈海生, 王光华, 刘建飞, 等. 模拟生态沟渠中盘培牧草降解农业面源污染效应的研究[J]. 江西农业学报,2010,22(9):143-145. doi: 10.3969/j.issn.1001-8581.2010.09.045CHEN H S, WANG G H, LIU J F, et al. Research on effects of simulative ecological ditch on degradation of agricultural non-point pollution[J]. Acta Agriculturae Jiangxi,2010,22(9):143-145. doi: 10.3969/j.issn.1001-8581.2010.09.045 [9] 余红兵, 肖润林, 杨知建, 等. 灌溉和降雨条件下生态沟渠氮、磷输出特征研究[J]. 长江流域资源与环境,2014,23(5):686-692.YU H B, XIAO R L, YANG Z J, et al. Study on the characteristics of nitrogen and phosphorus transportation through ecological ditch during irrigation and rainfall[J]. Resources and Environment in the Yangtze Basin,2014,23(5):686-692. [10] 张树楠, 肖润林, 刘锋, 等. 生态沟渠对氮、磷污染物的拦截效应[J]. 环境科学,2015,36(12):4516-4522.ZHANG S N, XIAO R L, LIU F, et al. Interception effect of vegetated drainage ditch on nitrogen and phosphorus from drainage ditches[J]. Environmental Science,2015,36(12):4516-4522. [11] WU Y H, KERR P G, HU Z Y, et al. Eco-restoration: simultaneous nutrient removal from soil and water in a complex residential-cropland area[J]. Environmental Pollution,2010,158(7):2472-2477. doi: 10.1016/j.envpol.2010.03.020 [12] NSENGA KUMWIMBA M, ZHU B, WANG T, et al. Nutrient dynamics and retention in a vegetated drainage ditch receiving nutrient-rich sewage at low temperatures[J]. Science of the Total Environment,2020,741:140268. doi: 10.1016/j.scitotenv.2020.140268 [13] WANG T, ZHU B, ZHOU M H. Ecological ditch system for nutrient removal of rural domestic sewage in the hilly area of the central Sichuan Basin, China[J]. Journal of Hydrology,2019,570:839-849. doi: 10.1016/j.jhydrol.2019.01.034 [14] KUMWIMBA M N, ZHU B, MUYEMBE D K, et al. Growth characteristics and nutrient removal capability of eco-ditch plants in mesocosm sediment receiving primary domestic wastewater[J]. Environmental Science and Pollution Research International,2017,24(30):23926-23938. doi: 10.1007/s11356-017-9992-3 [15] 常小云, 张树楠, 张苗苗, 等. 绿狐尾藻生态沟渠在低温状态下对磷的去除[J]. 农业环境科学学报,2021,40(4):852-858.CHANG X Y, ZHANG S N, ZHANG M M, et al. Phosphorus removal in Myriophyllum aquaticum ditch under low-temperature conditions[J]. Journal of Agro-Environment Science,2021,40(4):852-858. [16] CHEN L, LIU F, WANG Y, et al. Nitrogen removal in an ecological ditch receiving agricultural drainage in subtropical central China[J]. Ecological Engineering,2015,82:487-492. doi: 10.1016/j.ecoleng.2015.05.012 [17] WEBB B W, PHILLIPS J M, WALLING D E, et al. Load estimation methodologies for British Rivers and their relevance to the LOIS RACS(R) programme[J]. Science of the Total Environment,1997,194/195:379-389. doi: 10.1016/S0048-9697(96)05377-6 [18] 张真真, 单延功, 郭红丽, 等. 降雨特征对低山丘陵区典型小流域水土流失的影响[J]. 水土保持通报,2020,40(4):32-38.ZHANG Z Z, SHAN Y G, GUO H L, et al. Effects of rainfall characteristics on soil and water loss of small watershed in low mountains and hills area[J]. Bulletin of Soil and Water Conservation,2020,40(4):32-38. [19] 徐勇峰. 洪泽湖河湖交汇区麦稻两熟农田径流氮磷流失特征研究[D]. 南京: 南京林业大学, 2017. [20] 汪兆辉, 张友良, 冯绍元. 旱地硝态氮淋失阻控措施研究进展[J]. 中国农村水利水电,2021(12):39-45.WANG Z H, ZHANG Y L, FENG S Y. Review of soil nitrate leaching control measures in dry farmland[J]. China Rural Water and Hydropower,2021(12):39-45. [21] 房祥吉. 灌水量、沙粘比和施肥处理对苹果15N吸收、利用与损失影响的研究[D]. 泰安: 山东农业大学, 2011. [22] 朱兆良. 农田中氮肥的损失与对策[J]. 土壤与环境,2000,9(1):1-6.ZHU Z L. Loss of fertilizer N from plants-soil system and the strategies and techniques for its reduction[J]. Soil and Environmental Sciences,2000,9(1):1-6. [23] 张丰粟. 生态沟渠植物配置对村落污水中氮的去除效率及温室气体排放的影响[D]. 北京: 中国科学院大学, 2020. [24] 顾兆俊, 刘兴国, 程果锋, 等. 淡水池塘4种生态沟渠净化效果研究[J]. 江苏农业科学,2020,48(13):285-291.GU Z J, LIU X G, CHENG G F, et al. Study on purification effect of four ecological ditches of freshwater ponds[J]. Jiangsu Agricultural Sciences,2020,48(13):285-291. [25] 骆其金, 周昭阳, 黎京士, 等. 滤坝系统对城市初期雨水的净化效果[J]. 环境工程技术学报,2019,9(3):282-285.LUO Q J, ZHOU Z Y, LI J S, et al. The purification effects of infiltrative dams on urban initial rainwater[J]. Journal of Environmental Engineering Technology,2019,9(3):282-285. [26] 谢丽凤, 陆开宏, 胡智勇, 等. 多花黑麦草对不同形态氮的吸收动力学特征研究[J]. 生态科学,2010,29(3):229-233.XIE L F, LU K H, HU Z Y, et al. Study on the uptake kinetics of ammonium and nitrate in Lolium multiflorum Lam[J]. Ecological Science,2010,29(3):229-233. [27] 王沛芳, 娄明月, 钱进, 等. 农田退水净污湿地对污染物的净化效果及机理分析[J]. 水资源保护,2020,36(5):1-10. doi: 10.3880/j.issn.1004-6933.2020.05.001WANG P F, LOU M Y, QIAN J, et al. Analysis of purification effect and mechanism of pollutant by the farmland drainage wetland[J]. Water Resources Protection,2020,36(5):1-10. doi: 10.3880/j.issn.1004-6933.2020.05.001 [28] SAEED T, SUN G Z. A review on nitrogen and organics removal mechanisms in subsurface flow constructed wetlands: dependency on environmental parameters, operating conditions and supporting media[J]. Journal of Environmental Management,2012,112:429-448. doi: 10.1016/j.jenvman.2012.08.011 [29] LUO P, LIU F, ZHANG S N, et al. Evaluating organics removal performance from lagoon-pretreated swine wastewater in pilot-scale three-stage surface flow constructed wetlands[J]. Chemosphere,2018,211:286-293. doi: 10.1016/j.chemosphere.2018.07.174 [30] 张迎颖, 闻学政, 李敏, 等. 农村汇水河浜生态修复组合工程处理效果分析[J]. 农业环境科学学报,2023,42(7):1563-1575. doi: 10.11654/jaes.2022-0804ZHANG Y Y, WEN X Z, LI M, et al. Removal efficiency of pollutants in the rural catchment branch by the combined engineering of ecological restoration[J]. Journal of Agro-Environment Science,2023,42(7):1563-1575. doi: 10.11654/jaes.2022-0804 [31] SULKAVA P, HUHTA V. Effects of hard frost and freeze-thaw cycles on decomposer communities and N mineralisation in boreal forest soil[J]. Applied Soil Ecology,2003,22:225-239. doi: 10.1016/S0929-1393(02)00155-5 [32] 师澜峰. 施加秸秆生物炭对冻融期黑土表层无机氮磷流失影响研究[D]. 沈阳: 沈阳农业大学, 2019. [33] 范昊明, 张瑞芳, 周丽丽, 等. 气候变化对东北黑土冻融作用与冻融侵蚀发生的影响分析[J]. 干旱区资源与环境,2009,23(6):48-53.FAN H M, ZHANG R F, ZHOU L L, et al. Impact of climate change on freeze-thaw function and freeze-thaw erosion in black soil region of Northeast China[J]. Journal of Arid Land Resources and Environment,2009,23(6):48-53. [34] 王艺璇, 仲秋维, 郑昕雨, 等. 冻融循环对土壤性状特征影响研究进展[J]. 中国土壤与肥料,2022(10):231-240.WANG Y X, ZHONG Q W, ZHENG X Y, et al. Research progress on the effects of freeze-thaw cycles on soil properties[J]. Soil and Fertilizer Sciences in China,2022(10):231-240. [35] WANG C Y, SAMPLE D J, BELL C. Vegetation effects on floating treatment wetland nutrient removal and harvesting strategies in urban stormwater ponds[J]. Science of the Total Environment,2014,499:384-393. doi: 10.1016/j.scitotenv.2014.08.063 [36] TONDERA K. Evaluating the performance of constructed wetlands for the treatment of combined sewer overflows[J]. Ecological Engineering,2019,137:53-59. ◇ doi: 10.1016/j.ecoleng.2017.10.009 -
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