This work aims to study the seasonal fluctuation in physicochemical characteristics, trophic status, and some pollutants influencing phytoplankton diversity, and water quality at a compact Kafr El-Shinawy drinking-water treatment plant, Damietta – Egypt seasonally during 2018. Phytoplankton distribution was affected by the trophic status of water, level of pollutants, and physicochemical treatment processes of water. The predominance of phytoplankton species, especially Aphanizomenon flos aquae (Cyanophyta), Gomphosphaeria lacustris (Cyanophyta), Microcystis aeruginosa (Cyanophyta), Nostoc punctiforme (Cyanophyta), Oscillatoria limnetica (Cyanophyta), Pediastrum simplex (Chlorophyta), and Melosira granulata (Bacillariophyta) in treated water was much less than that in raw water. Trihalomethanes (THMs) levels in treated waters were higher than in raw water, while lower concentrations of heavy metals were recorded in treated water. Intracellular levels of microcystins were lower, whereas the extracellular levels were higher in treated water than raw water, and the former recorded the highest level in raw water during summer. Hence, the levels of dissolved microcystins and THMs in treated water were higher especially during summer, the season of luxurious growth of Microcystis species. Trophic state index (TSI) was relatively high in raw water compared with treated water due to high concentrations of nutrients (total-P, total-N, nitrite, nitrate, and ammonia) in raw water.

这项工作旨在研究一个小型的Kafr El-Shinawy饮用水处理厂（达米埃塔-埃及）在2018年的季节性理化特征，营养状况和一些影响浮游植物多样性以及水质的污染物的季节性波动。浮游植物的分布受到以下因素的影响：水的营养状况，污染物水平和水的理化处理过程。浮游植物种类占优势，尤其是浮游藻（Aphanizomenon flos aquae，蓝藻），Gomphosphaeria lacustris（Cyanophyta），铜绿微囊藻（Cyanophyta），点状浮游点（Cyanophyta），Oscillatoria limnetica（Cyanophyta）。处理后的水中的叶绿藻（Chlorophyta）和Melosira granulata（芽孢杆菌）（Bacillariophyta）要比原水中的少得多。处理水中的三卤甲烷（THMs）水平高于原水中，而处理水中的重金属浓度较低。在处理过的水中，细胞内微囊藻毒素水平较低，而在原水中则更高，而在夏季，前者在原水中的细胞外水平最高。因此，经过处理的水中溶解的微囊藻毒素和THM的含量较高，尤其是在夏季（微囊藻的繁盛生长季节）物种。与原水相比，原水的营养状态指数（TSI）较高，这是由于原水中营养素（全磷，总氮，亚硝酸盐，硝酸盐和氨）的浓度较高。