بررسي پراكنش، فراواني و تغييرات فصلي ميكروجلبك هاي سد 15 خرداد قم

Distribution, Frequency and Seasonal Variation of Microalgae of 15 Khordad Dam, Qom, Iran

سابقه و هدف ميكروجلبك ها، جلبك هاي يك تا چند سلولي اند كه شرايط محيطي مناسب نظير دما و دوره طولاني نور و همچنين ورود مواد مغذي حاوي فسفر و نيترات بر فراواني و پراكنش آنها تاثير گذارده و بعضا باعث بروز مشكلات بهداشتي، زيست محيطي و فرايندي در تصفيه خانه هاي آب مي گردد. مواد و روش كارها اين مطالعه به منظور تعيين تراكم و تنوع ميكروجلبك ها در آب سد 15 خرداد در دو فصل زمستان و بهار، در مناطق مختلف سد و در ارتفاع يك و پنج متري با نمونه برداري و شناسايي و شمارش براساس مورفولوژي جلبك ها، انجام شده است. ﺘﺎﯾﺞ: ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽ دﻫﺪ از ﺟﻨﺲ ﻫﺎي ﻣﺨﺘﻠﻒ ﻣﯿﮑﺮوﺟﻠﺒﮑﯽ دﯾﺎﺗﻮﻣﻪ ﻫﺎ ﺑﺎ 41/1%، ﺟﻠﺒﮏ ﻫﺎي دوﺗﺎژه اي ﺑﺎ 32/5%، ﺟﻠﺒﮏ ﻫﺎي ﺳﺒﺰ ﺑﺎ 23/2% و ﺟﻠﺒﮏ ﻫﺎي ﺳﺒﺰ- آﺑﯽ ﺑﺎ 3/2% ﺑﻪ ﺗﺮﺗﯿﺐ ﻏﺎﻟﺐ ﺗﺮﯾﻦ ﺟﻮاﻣﻊ را ﺗﺸﮑﯿﻞ ﻣﯽ دﻫﻨﺪ. در ﻧﻤﻮﻧﻪ ﻫﺎي ﺑﺮداﺷﺘﯽ از ﮐﻞ ﺳﺪ، ﺟﻨﺲ ﻏﺎﻟﺐ، ﺟﻠﺒﮏ ﭘﺮﯾﺪﯾﻨﯿﻮم ﻣﯽ ﺑﺎﺷﺪ. ﺑﯿﺸﺘﺮﯾﻦ ﻣﻘﺪار ﻓﺮاواﻧﯽ در ارﺗﻔﺎع ﯾﮏ ﻣﺘﺮ، در ﻣﺎه ﺧﺮداد و ﮐﻨﺎره ﺿﻠﻊ ﻏﺮﺑﯽ و ﮐﻤﺘﺮﯾﻦ ﻣﻘﺪار ﻓﺮاواﻧﯽ در ارﺗﻔﺎع ﭘﻨﺞ ﻣﺘﺮ، در ﻣﺎه دي و ﮐﻨﺎره ﺿﻠﻊ ﺷﺮﻗﯽ اﺳﺖ )0.05

Microalgae are single-celled algae that have favorable environmental conditions such as temperature and long period of light as well as nutrients containing phosphorus and nitrate affect their abundance and distribution and sometimes cause health, environmental and process problems in water plant. Material and Methods: This study was carried out to determine the density and diversity of microalgae in the water of 15 Khordad Dam in two winter and spring seasons, in different areas of the dam at a height of one and five meters by sampling and identifying and counting based on algae morphology. Results: The results show that diatoms with (41.1%), binary algae with (32.5%), green algae with (23.2%) and green-blue algae with (41.1%) different microalgae. (3.2%) constitute the most dominant communities, respectively. In the samples taken from the entire dam, the dominant genus is Peridinium algae. The highest frequency was at one meter height in June and on the west side and the lowest frequency at five meters height was in December and on the east side (p<0.05). Conclusion: The results of this study will be effective in planning the operation management of different water treatment plants in Qom.