2.云南省高原山地生态与退化环境修复重点实验室,昆明 650091
1.School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China
2.Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, Kunming 650091, China
浮萍塘污水处理技术具有管理简便、运行成本低、可资源化回收氮磷污染物等优势。然而,因水体溶解氧(DO)不足造成的污染物去除率低的问题限制了该技术的推广应用。为此,本研究在浮萍塘前端引入曝气塘,构建中试曝气塘-浮萍塘联合系统,借此增加浮萍塘DO含量,并进一步考察了曝气时长(0、0.5、1、2和4 h)对污染物去除效果及浮萍生长的影响,以此探寻低耗高效的最佳曝气时长。结果表明,曝气塘可有效降低水体的浊度,但对氮磷去除的贡献较小,氮磷的去除以浮萍塘为主。曝气处理可显著提高曝气塘及浮萍塘水体DO含量和氧化还原电位(Eh),且DO和Eh随曝气时长的增加而上升。此外,曝气处理还能显著促进浮萍生长及其污染物的去除,但促进效果并未简单地随曝气时长的增加而提高。其中,TN、氨氮和浊度的去除率在曝气时长1 h时已基本达到峰值(去除率分别为58.42%、61.89%和89.90%),TP去除率虽在曝气时长4 h时最大(81.44%),但与曝气时长0.5 h(73.05%)相比并无显著差异;浮萍虽在曝气时长2 h时干基生长速率最高(8.00 g·(m
左右)相比也无显著差异,而曝气成本却成倍增加。因此,综合考虑污染物去除、浮萍生长及曝气成本,建议曝气时长不宜高于1 h,推荐0.5~1 h为佳。以上结果可为曝气塘-浮萍塘联合系统的应用及曝气时长的选择提供参考。
Duckweed-based pond (DP) has several advantages, such as simplicity of management, low operating costs and easy-recovering nitrogen and phosphorus, however, the low pollutant removal efficiency caused by low dissolved oxygen (DO) concentration in the pond water hampers its broad application. Thus, a pilot-scale combined system with an aeration pond (AP) before a DP was developed in this study to increase DO concentration and pollutant removal efficiency in the DP, meanwhile, the effects of aeration duration (0, 0.5, 1, 2 and 4 h, respectively) on the pollutant removal and duckweed growth were also investigated to determine the optimal aeration duration for low operating cost and high efficiency. The results showed that the AP could greatly reduce turbidity of the wastewater, but slightly contribute to nitrogen and phosphorus removals which mainly achieved by DP. Meanwhile, aeration treatment significantly increased DO and oxidation reduction potential (Eh) in AP and DP, and DO and Eh increased with the extension of aeration duration. Aeration treatment also significantly promoted duckweed growth and pollutant removal in the combined system, while this promotion didn’t increase with the extension of aeration duration. The removal efficiencies of TN,
-N and turbidity almost reached their respective peak value at 1 h of aeration duration (58.42%, 61.89% and 89.90%, respectively); although TP removal efficiency was the highest at 4 h of aeration duration (81.44%), there was not significant difference compared with that at 0.5 h of aeration duration (73.05%). The duckweed growth rate was the highest (8.00 g·(m
) at 2 h of aeration duration, while there was also not significant difference compared with that at 0.5 or 1 h of aeration durations (around 7.35 g·(m
), but the cost of aeration treatment doubled. Therefore, comprehensively considering the pollutant removal, the duckweed growth and the cost of aeration treatment, it is recommended that the aeration duration should be less than 1 h, and its optimal value was 0.5~1 h. The result provides an important reference for the selection of aeration duration and the application of the combined system of AP and DP.
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曝气塘中不同曝气时长下的水体DO、Eh和pH
DO, Eh and pH in the aeration ponds at different aeration durations
Removal efficiencies of pollutants in the aeration ponds at different aeration durations
浮萍塘中不同曝气时长下的水体DO、Eh和pH
DO, Eh and pH in the duckweed-based ponds at different aeration durations
不同曝气时长处理的浮萍塘中浮萍的生长速率及含水率
The growth rate and water content of duckweed in the duckweed ponds at different aeration durations
曝气塘-浮萍塘联合系统污染物去除率与曝气时长的关系
Relationship between pollutant removal efficiency and aeration durations in the combined system of aeration pond and duckweed-based pond
Pollutant concentration in the effluent of the aeration ponds (influent of the duckweed-based ponds) at different aeration durations
Pollutant concentration in the effluent of duckweed-based ponds at different aeration durations
[1] | KUMAR S, DESWAL S. Phytoremediation capabilities of Salvinia molesta, water hyacinth, water lettuce, and duckweed to reduce phosphorus in rice mill wastewater[J]. International Journal of Phytoremediation, 2020, 22(11): 1097-1109. doi: 10.1080/15226514.2020.1731729 |
[2] | ZHAO Y, FANG Y, JIN Y, et al. Potential of duckweed in the conversion of wastewater nutrients to valuable biomass: A pilot-scale comparison with water hyacinth[J]. Bioresource Technology, 2014, 163: 82-91. doi: 10.1016/j.biortech.2014.04.018 |
[3] | 金树权, 周金波, 包薇红, 等. 5种沉水植物的氮, 磷吸收和水质净化能力比较[J]. 环境科学, 2017, 38(1): 156-161. |
[4] | 杨帆, 刘赢男, 焉志远, 等. 阿什河流域10种水生植物对水质氮磷的净化能力比较[J]. 环境科学研究, 2018, 31(4): 708-714. |
[5] | LIU Y, XU H, YU C, et al. Multifaceted roles of duckweed in aquatic phytoremediation and bioproducts synthesis[J]. Global Change Biology Bioenergy, 2021, 13(1): 70-82. doi: 10.1111/gcbb.12747 |
[6] | CHENG J J, ANNE M S. Growing duckweed to recover nutrients from wastewaters and for production of fuel ethanol and animal feed[J]. Clean-Soil, Air, Water, 2009, 37(1): 17-26. doi: 10.1002/clen.200800210 |
[7] | MKANDAWIRE M, DUDEL E G. Are Lemna spp. effective phytoremediation agents?[J]. Bioremediation, Biodiversity and Bioavailability, 2007, 1(1): 56-71. |
[8] | AN D, ZHOU Y, LI C, et al. Plant evolution and environmental adaptation unveiled by long-read whole-genome sequencing of Spirodela[J]. Proceedings of the National Academy of Sciences of the United States of America, 2019, 116(38): 18893-18899. doi: 10.1073/pnas.1910401116 |
[9] | 韩玉洁, 杨琳, 赵玲, 等. 浮萍植物在水体净化中的研究及展望[J]. 生物学通报, 2016, 51(6): 4-7. |
[10] | IQBAL S. Duckweed aquaculture, potentials, possibilities and limitations, for combined wastewater treatment and animal feed production in developing countries[R]. Duebenderf, Switzerland: EAWAG/SANDEC, 1999. |
[11] | ZHAO Y, FANG Y, JIN Y, et al. Microbial community and removal of nitrogen via the addition of a carrier in a pilot-scale duckweed-based wastewater treatment system[J]. Bioresource Technology, 2015, 179: 549-558. doi: 10.1016/j.biortech.2014.12.037 |
[12] | 种云霄, 胡洪营, 崔理华, 等. 浮萍植物在污水处理中的应用研究进展[J]. 环境污染治理技术与设备, 2006, 7(3): 14-18. |
[13] | 高寒, 贺振洲, 赵军, 等. 组合型生态浮岛原位修复重污染水体[J]. 环境工程学报, 2019, 13(12): 2884-2889. doi: 10.12030/j.cjee.201901095 |
[14] | 刘丽香, 韩永伟, 刘辉, 等. 曝气技术对黑臭水体治理效果影响的研究进展[J]. 环境科学研究, 2020, 33(4): 932-939. |
[15] | 周高峰, 刘义青, 付永胜, 等. 微曝气强化生态浮床对污水中磷的净化效果[J]. 环境科学与技术, 2018, 41(10): 69-74. |
[16] | 聂玉华. 微曝气强化生态浮床对污水中氮元素的去除效果研究[D]. 成都: 西南交通大学, 2015. |
[17] | 宫志杰, 宋新山, 赵志淼, 等. 微曝气技术在强化人工湿地脱氮中的应用[J]. 环境科学与技术, 2017, 40(4): 132-135. |
[18] | ZHAO Y, FANG Y, JIN Y, et al. Effects of operation parameters on nutrient removal from wastewater and high-protein biomass production in a duckweed-based (Lemma aequinoctialis) pilot-scale system[J]. Water Science and Technology, 2014, 70(7): 1195-204. doi: 10.2166/wst.2014.334 |
[19] | BEN-SHALOM M, SHANDALOV S, BRENNER A, et al. The effect of aeration and effluent recycling on domestic wastewater treatment in a pilot-plant system of duckweed ponds[J]. Water Science and Technology, 2014, 69(2): 350-357. doi: 10.2166/wst.2013.720 |
[20] | 耿军军, 王亚宜, 张兆祥, 等. 污水生物脱氮革新工艺中强温室气体N2O的产生及微观机理[J]. 环境科学学报, 2010, 30(9): 1729-1738. |
[21] | 王旭, 王永刚, 孙长虹, 等. 城市黑臭水体形成机理与评价方法研究进展[J]. 应用生态学报, 2016, 27(4): 1331-1340. |
[22] | 黄岁樑, 臧常娟, 杜胜蓝, 等. pH、溶解氧、叶绿素a之间相关性研究Ⅰ: 养殖水体[J]. 环境工程学报, 2011, 5(6): 1201-1208. |
[23] | 赵紫涵, 宋贵生, 赵亮. 秦皇岛外海夏季溶解氧与pH的变化特征分析[J]. 海洋学报, 2020, 42(10): 148-158. |
[24] | 洪铭媛, 李清彪, 邓旭. 废水厌氧(水解)-好氧生物组合处理工艺研究进展[J]. 化工环保, 2005, 25(2): 104-109. doi: 10.3969/j.issn.1006-1878.2005.02.007 |
[25] | 耿显华. 大气CO2浓度升高对不同生活型水生植物的影响[D]. 武汉: 武汉大学, 2003. |
[26] | YAMAKAWA Y, JOG R, MORIKAWA M. Effects of co-inoculation of two different plant growth-promoting bacteria on duckweed[J]. Plant Growth Regulation, 2018, 86(2): 287-296. doi: 10.1007/s10725-018-0428-y |
[27] | BALIBAN R C, ELIA J A, FLOUDAS C A, et al. Thermochemical conversion of duckweed biomass to gasoline, diesel, and jet fuel: Process synthesis and global optimization[J]. Industrial Engineering Chemistry Research, 2013, 52(33): 11436-11450. doi: 10.1021/ie3034703 |
[28] | PAGLIUSO D, GRANDIS A, LAM E, et al. High saccharification, low lignin, and high sustainability potential make duckweeds adequate as bioenergy feedstocks[J]. Bioenergy Research, 2020, 28: 1-11. doi: 10.1007/s12155-020-10211-x |
[29] | APPENROTH K J, SREE K S, BOHM V, et al. Nutritional value of duckweeds (Lemnaceae) as human food[J]. Food Chemistry, 2017, 217: 266-273. doi: 10.1016/j.foodchem.2016.08.116 |
[30] | KREIDER A N, PULIDO C R F, BRUNS M A, et al. Duckweed as an agricultural amendment: Nitrogen mineralization, leaching, and sorghum uptake[J]. Journal of Environmental Quality, 2019, 48(2): 469-475. doi: 10.2134/jeq2018.05.0207 |
[31] | 朱新景, 张凡, 王星星, 等. 浮萍的药理作用研究进展[J]. 中医药导报, 2020, 360(14): 32-36. |
[32] | SMITH B. Harvesting duckweed by skimming[D]. Raleigh: North Carolina State University, 2003. |
[33] | 恽文荣, 陈玉荣, 李炳堂. 一种便携式浮萍收集装置的介绍[J]. 工程技术(引文版), 2016(3): 13. |
[34] | PENG J, WANG B, SONG Y, et al. Modeling N transformation and removal in a duckweed pond: Model development and calibration[J]. Ecological Modelling, 2007, 206(1): 147-152. |
[35] | MOHEDANO R A, COSTA R H R, TAVARES F A, et al. High nutrient removal rate from swine wastes and protein biomass production by full-scale duckweed ponds[J]. Bioresource Technology, 2012, 112(5): 98-104. |
[36] | 潘俊, 孙舶洋, 魏炜, 等. 微纳米曝气-生态浮岛联合技术处理氮磷污染水体[J]. 环境工程, 2020, 38(5): 49-53. |
[37] | 荣宏伟, 彭永臻, 张朝升, 等. 曝气量对SBBR生物除磷的影响研究[J]. 中国给水排水, 2008, 24(5): 72-76. doi: 10.3321/j.issn:1000-4602.2008.05.018 |