绿狐尾藻分解及其氮磷释放特征
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摘要
湿地植物分解释放的有机物、氮和磷等会影响人工湿地对水体污染物的去除效率和出水水质.本研究采用尼龙分解袋法研究绿狐尾藻在水中的分解过程及氮磷释放特征.连续60 d的室内分解实验结果表明,前期(0～4 d)绿狐尾藻干物质质量损失速率快,占初始质量的30%,中后期(4～60 d)损失速率减慢,占31%.拟合的一级动力学分解速率常数为0. 014 2d-1,降解50%的干物质需48. 8 d.水体p H值变化情况:0～4 d从7. 60迅速下降到5. 63;中期趋于稳定;后期p H值回升到7. 03,与空白对照值接近.绿狐尾藻分解实验系统中溶解氧浓度从6. 30 mg·L~(-1)在1 d内快速下降到0. 61 mg·L~(-1),表明该系统一直处于厌氧状态.水中总氮浓度0～2 h迅速增加达到12. 7 mg·L~(-1),2 h～32 d逐渐降低到5. 80 mg·L~(-1),后期略有增加;总磷浓度初期快速升高到18. 4 mg·L~(-1),中后期趋于稳定.有机氮(占总氮65. 7%～94. 7%)和无机磷(占总磷61%～89%)是主要的氮磷存在形态.绿狐尾藻体内总氮含量随分解时间逐渐增加,从24. 3 mg·g~(-1)上升到60. 5 mg·g~(-1);而总磷含量从6. 09 mg·g~(-1)下降到2. 94 mg·g~(-1)后波动稳定,这可能与附着微生物对氮的吸收和固定等因素有关.本研究证实绿狐尾藻分解过程释放的氮磷营养元素会引起水体二次污染,为此采用合理的植物收割管理措施非常必要.
Decomposition of wetland plants could release pollutants,which may affect the removal efficiency and effluent quality of constructed wetlands. The experimental decomposition test of Myriophyllum aquaticum was carried out for 60 d using nylon bags,and release characteristics of nitrogen and phosphorus during the decomposition process were studied. The results showed that the decomposition rate of M. aquaticum was fastest during the first 0-4 d,with a weight loss of 30%,while the degradation rate slowed gradually during the period 4-60 d,with weight loss of 31%. The fitting first-order kinetic decomposition rate constant was 0. 014 2 d-1,and the calculated time to degrade 50% of dry matter was 48. 8 d. The water p H decreased rapidly from 7. 60 to 5. 63 during 0-4 d,stabilized during 4-32 d,and finally increased to 7. 03( which was close to the control sample without M. aquaticum). The dissolved oxygen concentration decreased rapidly from 6. 30 mg·L~(-1) to 0. 61 mg·L~(-1) during 0-4 d,and remained in an anaerobic state. The total nitrogen concentration in the water increased rapidly to 12. 7 mg·L~(-1) within 2 h,gradually decreased to 5. 80 mg·L~(-1) during 2 h-32 d,and then finally increased slightly. The phosphorus concentration increased rapidly to 18. 4 mg·L~(-1) at the beginning of the experiment,and then gradually stabilized. The main forms of nitrogen and phosphorus released by M. aquaticum were organic nitrogen( accounting for 65. 7%-94. 7% of total nitrogen) and inorganic phosphorus( accounting for 61%-89% of total phosphorus),respectively. The total nitrogen content of M. aquaticum increased from 24. 3 mg·g~(-1) to 60. 5 mg·g~(-1) with increasing degradation time; the total phosphorus decreased initially from 6. 09 mg·g~(-1) to 2. 94 mg·g~(-1) and then remained constant. These trends may have been related to the fixation of nitrogen by attached microorganisms. Therefore,suitable harvesting and management strategies should be adopted for wetland plants to reduce secondary pollution.
Decomposition of wetland plants could release pollutants,which may affect the removal efficiency and effluent quality of constructed wetlands. The experimental decomposition test of Myriophyllum aquaticum was carried out for 60 d using nylon bags,and release characteristics of nitrogen and phosphorus during the decomposition process were studied. The results showed that the decomposition rate of M. aquaticum was fastest during the first 0-4 d,with a weight loss of 30%,while the degradation rate slowed gradually during the period 4-60 d,with weight loss of 31%. The fitting first-order kinetic decomposition rate constant was 0. 014 2 d-1,and the calculated time to degrade 50% of dry matter was 48. 8 d. The water p H decreased rapidly from 7. 60 to 5. 63 during 0-4 d,stabilized during 4-32 d,and finally increased to 7. 03( which was close to the control sample without M. aquaticum). The dissolved oxygen concentration decreased rapidly from 6. 30 mg·L~(-1) to 0. 61 mg·L~(-1) during 0-4 d,and remained in an anaerobic state. The total nitrogen concentration in the water increased rapidly to 12. 7 mg·L~(-1) within 2 h,gradually decreased to 5. 80 mg·L~(-1) during 2 h-32 d,and then finally increased slightly. The phosphorus concentration increased rapidly to 18. 4 mg·L~(-1) at the beginning of the experiment,and then gradually stabilized. The main forms of nitrogen and phosphorus released by M. aquaticum were organic nitrogen( accounting for 65. 7%-94. 7% of total nitrogen) and inorganic phosphorus( accounting for 61%-89% of total phosphorus),respectively. The total nitrogen content of M. aquaticum increased from 24. 3 mg·g~(-1) to 60. 5 mg·g~(-1) with increasing degradation time; the total phosphorus decreased initially from 6. 09 mg·g~(-1) to 2. 94 mg·g~(-1) and then remained constant. These trends may have been related to the fixation of nitrogen by attached microorganisms. Therefore,suitable harvesting and management strategies should be adopted for wetland plants to reduce secondary pollution.
引文
[1] Kadlec R H,Wallace S D. Treatment wetlands(2nd ed.)[M].Boca Raton,FL:CRC Press,2008. 3-5.
[2] Vymazal J. Removal of nutrients in various types of constructed wetlands[J]. Science of the Total Environment,2007,380(1-3):48-65.
[3]刘锋,罗沛,刘新亮,等.绿狐尾藻生态湿地处理污染水体的研究评述[J].农业现代化研究,2018,39(6):1020-1029.Liu F, Luo P, Liu X L, et al. Research advances of Myriophyllum spp.-based wetland for wastewater treatment and resource utilization[J]. Research of Agricultural modernization,2018,39(6):1020-1029.
[4] Serna A,Richards J H,Scinto L J. Plant decomposition in wetlands:effects of hydrologic variation in a re-created everglades[J]. Journal of Environmental Quality,2013,42(2):562-572.
[5] Cheesman A W,Turner B L,Inglett P W,et al. Phosphorus transformations during decomposition of wetland macrophytes[J].Environmental Science&Technology,2010,44(24):9265-9271.
[6]叶春,王博,李春华,等.沉水植物黑藻腐解过程中营养盐释放过程[J].中国环境科学,2014,34(10):2653-2659.Ye C,Wang B,Li C H,et al. Nutrient release process during decomposition of submerged macrophytes(Hydrilla verticillata Royle)[J]. China Environmental Science,2014,34(10):2653-2659.
[7]陈志刚,林志军,周晓红,等.菹草腐烂分解过程中污染物的动态释放[J].干旱区资源与环境,2017,31(8):153-159.Chen Z G,Lin Z J,Zhou X H,et al. Pollutants dynamic release of Potamogeton crispus during decomposition process[J]. Journal of Arid Land Resources and Environment,2017,31(8):153-159.
[8] Wu S Q, He S B, Zhou W L, et al. Decomposition characteristics of three different kinds of aquatic macrophytes and their potential application as carbon resource in constructed wetland[J]. Environmental Pollution, 2017, 231:1122-1133.
[9]潘慧云,徐小花,高士祥.沉水植物衰亡过程中营养盐的释放过程及规律[J].环境科学研究,2008,21(1):64-68.Pan H Y,Xu X H,Gao S X. Study on process of nutrition release during the decay of submerged macrophytes[J]. Research of Environmental Sciences,2008,21(1):64-68.
[10] Overbeek C C,van der Geest H G,van Loon E E,et al.Decomposition of aquatic pioneer vegetation in newly constructed wetlands[J]. Ecological Engineering,2018,114:154-161.
[11] Liu F,Zhang S N,Luo P,et al. Purification and reuse of nonpoint source wastewater via Myriophyllum-based integrative biotechnology:a review[J]. Bioresource Technology,2018,248:3-11.
[12] Luo P,Liu F,Zhang S N,et al. Nitrogen removal and recovery from lagoon-pretreated swine wastewater by constructed wetlands under sustainable plant harvesting management[J]. Bioresource Technology,2018,258:247-254.
[13]易文利,王圣瑞,杨苏文,等.有机质腐解对穗花狐尾藻生长及磷积累的影响[J].生态环境学报,2011,20(5):940-945.Yi W L,Wang S R,Yang S W,et al. Effects of organic matter decomposition on the growth and phosphorus accumulation of Myriophyllum spicatum[J]. Ecology and Environmental Sciences,2011,20(5):940-945.
[14]武海涛,吕宪国,杨青.分解袋法在湿地枯落物分解研究中存在的问题与对策[J].东北林业大学学报,2007,35(2):82-85.Wu H T, LüX G, Yang Q. Existing problems and countermeasures of litter bag technique applied to emergent macrophyte litter decomposition in wetland[J]. Journal of Northeast Forestry University,2007,35(2):82-85.
[15] Luai V B,Ding S B,Wang D. The effects of litter quality and living plants on the home-field advantage of aquatic macrophyte decomposition in a eutrophic urban lake,China[J]. Science of the Total Environment,2019,650:1529-1536.
[16]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.
[17]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.
[18] Brodersen K E,Koren K,Mohammer M,et al. Seagrassmediated phosphorus and iron solubilization in tropical sediments[J]. Environmental Science&Technology,2017,51(24):14155-14163.
[19]武海涛,吕宪国,杨青,等.三江平原典型湿地枯落物早期分解过程及影响因素[J].生态学报,2007,27(10):4027-4035.Wu H T, LüX G, Yang Q, et al. The early-stage litter decomposition and its influencing factors in the wetland of the Sanjiang Plain,China[J]. Acta Ecologica Sinica,2007,27(10):4027-4035.
[20] Shilla D,Asaeda T,Fujino T,et al. Decomposition of dominant submerged macrophytes:implications for nutrient release in Myall Lake,NSW,Australia[J]. Wetlands Ecology and Management,2006,14(5):427-433.
[21] Zhang L S,Zhang S H,Lv X Y,et al. Dissolved organic matter release in overlying water and bacterial community shifts in biofilm during the decomposition of Myriophyllum verticillatum[J]. Science of the Total Environment,2018,633:929-937.
[22]曹培培,刘茂松,唐金艳,等.几种水生植物腐解过程的比较研究[J].生态学报,2014,34(14):3848-3858.Cao P P,Liu M S,Tang J Y,et al. A comparative study on the decomposition processes among some aquatic plants[J]. Acta Ecologica Sinica,2014,34(14):3848-3858.
[23]杨继松,刘景双,于君宝,等.三江平原沼泽湿地枯落物分解及其营养动态[J].生态学报,2006,26(5):1297-1302.Yang J S,Liu J S,Yu J B,et al. Decomposition and nutrient dynamics of marsh litter in the Sanjiang Plain,China[J]. Acta Ecologica Sinica,2006,26(5):1297-1302.
[24] Gessner M O. Breakdown and nutrient dynamics of submerged Phragmites shoots in the littoral zone of a temperate hardwater lake[J]. Aquatic Botany,2000,66(1):9-20.
[25]侯雪薇,张桂斋,李静,等.两种沉水植物分解过程及温度影响的模拟研究[J].山东大学学报(理学版),2015,50(11):23-31.Hou X W,Zhang G Z,Li J,et al. Decomposition processes and simulation of two species of submerged plants under different temperatures[J]. Journal of Shandong University(Natural Science),2015,50(11):23-31.
[26]邵学新,梁新强,吴明,等.杭州湾潮滩湿地植物不同分解过程及其磷素动态[J].环境科学,2014,35(9):3381-3388.Shao X X, Liang X Q, Wu M, et al. Decomposition and phosphorus dynamics of the litters in standing and litterbag of the Hangzhou Bay coastal wetland[J]. Environmental Science,2014,35(9):3381-3388.
[27]黄耀,沈雨,周密,等.木质素和氮含量对植物残体分解的影响[J].植物生态学报,2003,27(2):183-188.Huang Y,Shen Y,Zhou M,et al. Decomposition of plant residue as influenced by its lignin and n itrogen[J]. Acta Phytoecologica Sinica,2003,27(2):183-188.
[28] Chimney M J,Pietro K C. Decomposition of macrophyte litter in a subtropical constructed wetland in south Florida(USA)[J].Ecological Engineering,2006,27(4):301-321.
[29]唐金艳,曹培培,徐驰,等.水生植物腐烂分解对水质的影响[J].应用生态学报,2013,24(1):83-89.Tang J Y,Cao P P,Xu C,et al. Effects of aquatic plants during their decay and decomposition on water quality[J]. Chinese Journal of Applied Ecology,2013,24(1):83-89.
[30] Duan H,Wang L,Zhang Y N,et al. Variable decomposition of two plant litters and their effects on the carbon sequestration ability of wetland soil in the Yangtze River estuary[J].Geoderma,2018,319:230-238.
[31]张菊,邓焕广,王东启,等.徒骇河沉水植物腐烂对上覆水体中营养盐形态变化影响[J].环境科学与技术,2011,34(5):14-19.Zhang J,Deng H G,Wang D Q,et al. Impact of decomposition of submerged macrophytes on nutrient speciation concentration in overlying water of Tuhai River[J]. Environmental Science&Technology,2011,34(5):14-19.
[32]谢宝东,方升佐,綦山丁,等.四种生物覆盖植物的自然分解及养分释放动态[J].南京林业大学学报(自然科学版),2009,33(5):12-16.Xie B D,Fang S Z,Qi S D,et al. Decomposition and nutrient release of four mulching plants in the upland area of Guizhou Province[J]. Journal of Nanjing Forestry University(Natural Science Edition),2009,33(5):12-16.
[33]王立志,王国祥.衰亡期沉水植物对水和沉积物磷迁移的影响[J].生态学报,2013,33(17):5426-5437.Wang L Z,Wang G X. Influence of submerged macrophytes on phosphorus transference between sediment and overlying water in decomposition period[J]. Acta Ecologica Sinica,2013,33(17):5426-5437.
[2] Vymazal J. Removal of nutrients in various types of constructed wetlands[J]. Science of the Total Environment,2007,380(1-3):48-65.
[3]刘锋,罗沛,刘新亮,等.绿狐尾藻生态湿地处理污染水体的研究评述[J].农业现代化研究,2018,39(6):1020-1029.Liu F, Luo P, Liu X L, et al. Research advances of Myriophyllum spp.-based wetland for wastewater treatment and resource utilization[J]. Research of Agricultural modernization,2018,39(6):1020-1029.
[4] Serna A,Richards J H,Scinto L J. Plant decomposition in wetlands:effects of hydrologic variation in a re-created everglades[J]. Journal of Environmental Quality,2013,42(2):562-572.
[5] Cheesman A W,Turner B L,Inglett P W,et al. Phosphorus transformations during decomposition of wetland macrophytes[J].Environmental Science&Technology,2010,44(24):9265-9271.
[6]叶春,王博,李春华,等.沉水植物黑藻腐解过程中营养盐释放过程[J].中国环境科学,2014,34(10):2653-2659.Ye C,Wang B,Li C H,et al. Nutrient release process during decomposition of submerged macrophytes(Hydrilla verticillata Royle)[J]. China Environmental Science,2014,34(10):2653-2659.
[7]陈志刚,林志军,周晓红,等.菹草腐烂分解过程中污染物的动态释放[J].干旱区资源与环境,2017,31(8):153-159.Chen Z G,Lin Z J,Zhou X H,et al. Pollutants dynamic release of Potamogeton crispus during decomposition process[J]. Journal of Arid Land Resources and Environment,2017,31(8):153-159.
[8] Wu S Q, He S B, Zhou W L, et al. Decomposition characteristics of three different kinds of aquatic macrophytes and their potential application as carbon resource in constructed wetland[J]. Environmental Pollution, 2017, 231:1122-1133.
[9]潘慧云,徐小花,高士祥.沉水植物衰亡过程中营养盐的释放过程及规律[J].环境科学研究,2008,21(1):64-68.Pan H Y,Xu X H,Gao S X. Study on process of nutrition release during the decay of submerged macrophytes[J]. Research of Environmental Sciences,2008,21(1):64-68.
[10] Overbeek C C,van der Geest H G,van Loon E E,et al.Decomposition of aquatic pioneer vegetation in newly constructed wetlands[J]. Ecological Engineering,2018,114:154-161.
[11] Liu F,Zhang S N,Luo P,et al. Purification and reuse of nonpoint source wastewater via Myriophyllum-based integrative biotechnology:a review[J]. Bioresource Technology,2018,248:3-11.
[12] Luo P,Liu F,Zhang S N,et al. Nitrogen removal and recovery from lagoon-pretreated swine wastewater by constructed wetlands under sustainable plant harvesting management[J]. Bioresource Technology,2018,258:247-254.
[13]易文利,王圣瑞,杨苏文,等.有机质腐解对穗花狐尾藻生长及磷积累的影响[J].生态环境学报,2011,20(5):940-945.Yi W L,Wang S R,Yang S W,et al. Effects of organic matter decomposition on the growth and phosphorus accumulation of Myriophyllum spicatum[J]. Ecology and Environmental Sciences,2011,20(5):940-945.
[14]武海涛,吕宪国,杨青.分解袋法在湿地枯落物分解研究中存在的问题与对策[J].东北林业大学学报,2007,35(2):82-85.Wu H T, LüX G, Yang Q. Existing problems and countermeasures of litter bag technique applied to emergent macrophyte litter decomposition in wetland[J]. Journal of Northeast Forestry University,2007,35(2):82-85.
[15] Luai V B,Ding S B,Wang D. The effects of litter quality and living plants on the home-field advantage of aquatic macrophyte decomposition in a eutrophic urban lake,China[J]. Science of the Total Environment,2019,650:1529-1536.
[16]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.
[17]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.
[18] Brodersen K E,Koren K,Mohammer M,et al. Seagrassmediated phosphorus and iron solubilization in tropical sediments[J]. Environmental Science&Technology,2017,51(24):14155-14163.
[19]武海涛,吕宪国,杨青,等.三江平原典型湿地枯落物早期分解过程及影响因素[J].生态学报,2007,27(10):4027-4035.Wu H T, LüX G, Yang Q, et al. The early-stage litter decomposition and its influencing factors in the wetland of the Sanjiang Plain,China[J]. Acta Ecologica Sinica,2007,27(10):4027-4035.
[20] Shilla D,Asaeda T,Fujino T,et al. Decomposition of dominant submerged macrophytes:implications for nutrient release in Myall Lake,NSW,Australia[J]. Wetlands Ecology and Management,2006,14(5):427-433.
[21] Zhang L S,Zhang S H,Lv X Y,et al. Dissolved organic matter release in overlying water and bacterial community shifts in biofilm during the decomposition of Myriophyllum verticillatum[J]. Science of the Total Environment,2018,633:929-937.
[22]曹培培,刘茂松,唐金艳,等.几种水生植物腐解过程的比较研究[J].生态学报,2014,34(14):3848-3858.Cao P P,Liu M S,Tang J Y,et al. A comparative study on the decomposition processes among some aquatic plants[J]. Acta Ecologica Sinica,2014,34(14):3848-3858.
[23]杨继松,刘景双,于君宝,等.三江平原沼泽湿地枯落物分解及其营养动态[J].生态学报,2006,26(5):1297-1302.Yang J S,Liu J S,Yu J B,et al. Decomposition and nutrient dynamics of marsh litter in the Sanjiang Plain,China[J]. Acta Ecologica Sinica,2006,26(5):1297-1302.
[24] Gessner M O. Breakdown and nutrient dynamics of submerged Phragmites shoots in the littoral zone of a temperate hardwater lake[J]. Aquatic Botany,2000,66(1):9-20.
[25]侯雪薇,张桂斋,李静,等.两种沉水植物分解过程及温度影响的模拟研究[J].山东大学学报(理学版),2015,50(11):23-31.Hou X W,Zhang G Z,Li J,et al. Decomposition processes and simulation of two species of submerged plants under different temperatures[J]. Journal of Shandong University(Natural Science),2015,50(11):23-31.
[26]邵学新,梁新强,吴明,等.杭州湾潮滩湿地植物不同分解过程及其磷素动态[J].环境科学,2014,35(9):3381-3388.Shao X X, Liang X Q, Wu M, et al. Decomposition and phosphorus dynamics of the litters in standing and litterbag of the Hangzhou Bay coastal wetland[J]. Environmental Science,2014,35(9):3381-3388.
[27]黄耀,沈雨,周密,等.木质素和氮含量对植物残体分解的影响[J].植物生态学报,2003,27(2):183-188.Huang Y,Shen Y,Zhou M,et al. Decomposition of plant residue as influenced by its lignin and n itrogen[J]. Acta Phytoecologica Sinica,2003,27(2):183-188.
[28] Chimney M J,Pietro K C. Decomposition of macrophyte litter in a subtropical constructed wetland in south Florida(USA)[J].Ecological Engineering,2006,27(4):301-321.
[29]唐金艳,曹培培,徐驰,等.水生植物腐烂分解对水质的影响[J].应用生态学报,2013,24(1):83-89.Tang J Y,Cao P P,Xu C,et al. Effects of aquatic plants during their decay and decomposition on water quality[J]. Chinese Journal of Applied Ecology,2013,24(1):83-89.
[30] Duan H,Wang L,Zhang Y N,et al. Variable decomposition of two plant litters and their effects on the carbon sequestration ability of wetland soil in the Yangtze River estuary[J].Geoderma,2018,319:230-238.
[31]张菊,邓焕广,王东启,等.徒骇河沉水植物腐烂对上覆水体中营养盐形态变化影响[J].环境科学与技术,2011,34(5):14-19.Zhang J,Deng H G,Wang D Q,et al. Impact of decomposition of submerged macrophytes on nutrient speciation concentration in overlying water of Tuhai River[J]. Environmental Science&Technology,2011,34(5):14-19.
[32]谢宝东,方升佐,綦山丁,等.四种生物覆盖植物的自然分解及养分释放动态[J].南京林业大学学报(自然科学版),2009,33(5):12-16.Xie B D,Fang S Z,Qi S D,et al. Decomposition and nutrient release of four mulching plants in the upland area of Guizhou Province[J]. Journal of Nanjing Forestry University(Natural Science Edition),2009,33(5):12-16.
[33]王立志,王国祥.衰亡期沉水植物对水和沉积物磷迁移的影响[J].生态学报,2013,33(17):5426-5437.Wang L Z,Wang G X. Influence of submerged macrophytes on phosphorus transference between sediment and overlying water in decomposition period[J]. Acta Ecologica Sinica,2013,33(17):5426-5437.