摘要
在太湖采集沉积物样品开展室内沉积物-水柱培养试验,设置“空白-好氧”“加藻-好氧”“加藻-厌氧”3组沉积物柱对照,探讨藻体死亡分解对水体环境条件、水体硫化物(S^2-)和沉积物中酸可挥发性硫化物(AVS)迁移转化的影响。结果表明,培养期间藻体死亡分解促使“加藻-好氧”“加藻-厌氧”组上覆水pH下降明显,溶解氧(DO)前期因光合作用而暂时升高,后期因呼吸耗氧而降低。在20 d培养期间,“空白-好氧”组上覆水中S^2-均未检测到,而两个“加藻”组上覆水中S^2-在第5 d和第20 d明显增加,说明藻体分解向上覆水中释放了部分S^2-。3个试验组的表层沉积物AVS含量均低于第二层沉积物AVS含量,原因可能是表层沉积物AVS更易被氧化或释放进入上覆水。“加藻-厌氧”组表层沉积物AVS含量在1~10 d逐渐增加,此部分AVS主要由藻体自身分解释放的部分S^2-所贡献。研究表明,藻体分解过程一方面可通过改变pH、DO等环境条件促进沉积物硫迁移转化,另一方面藻体自身释放S^2-也影响沉积物-水体硫化物含量。
Sediment samples were sampled in Taihu Lake and cultivated with water and algae in laboratory.Three groups of sediment columns were set up as“Blank-Aerobic”,“Algae-Aerobic”and“Algae-Anaerobic”to analyze the variations of pH,dissolved oxygen(DO)in overlying water and reveal the influence of algal decomposition on the migration and transformation of water sulfide(S^2-)and acid volatile sulfide in sediment(AVS).The results showed that the algae death decomposition during the culture period promoted a significant decrease in the pH of the overlying water in the“Algae-Aerobic”and“Algae-Anaerobic”groups.Dissolved oxygen(DO)increased temporarily due to photosynthesis in the early stage,and decreased due to respiration and oxygen consumption in the later stage.During 20 days of cultivation,S^2-in the overlying water were not detected in group of“Blank-Aerobic”,whereas algal decomposition led to the obvious increases of S^2-in the overlying water in the groups of“Algae-Aerobic”and“Algae-Anaerobic”on the 5th and 20th day,indicating that the algae decomposition released part of S^2-to the overlying water.All AVS contents in the surface sediment in the three experimental groups were lower than that in the second sediment layer,probably because AVS in the surface sediment were more easily oxidized or be released into the overlying water than the second sediment layer.The AVS contents in the surface sediment in the group of“Algae-Anaerobic”gradually increased from the first day to the 10th day,which were mainly contributed by the released S^2-due to algal decomposition.The results indicated that algal decomposition process can promote sediment sulfur migration and transformation by changing pH,DO in water,and the S^2-released from decomposing algae also affected sulfide contents in water and sediment.
作者
赵香香
韩超南
吴昊
沈叶
ZHAO Xiangxiang;HAN Chaonan;WU Hao;SHEN Ye(School of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China)
出处
《森林工程》
2020年第6期36-41,共6页
Forest Engineering
基金
江苏省自然科学基金青年项目(SBK2019044279)
南京林业大学大学生实践创新计划项目(2019NFUSPITP0474,201910298044Z)
南京林业大学水杉师资人才科研启动项目(163050123)。
关键词
藻体死亡分解
硫化物
迁移转化
沉积物
水体
Algal decomposition
sulfide
migration and transformation
sediment
water
