Grupo de Ecología y Fisiología de Fitoplancton, Sección Limnología, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400, Montevideo, Uruguay.
Environ Monit Assess. 2019 Feb 9;191(3):146. doi: 10.1007/s10661-019-7288-4.
The main drinking water source supplying Uruguay (Santa Lucía River, SLR) was threatened in 2013 by a cyanobacterial bloom transported downstream to the water treatment plant that provides water to half of this country population. Several eutrophic reservoirs and stabilization ponds located in the river basin may have been the source of cyanobacterial populations. Such conditions may be common in productive basins; however, few studies have evaluated the impact of microalgae from wastewater stabilization ponds on rivers and its viability downstream. The effect of a dairy wastewater effluent on SLR was studied by means of nutrient and chlorophyll a loads, phytoplankton composition, and effluent incubation in river water in order to evaluate the potential development of cyanobacteria. Total phosphorus and nitrogen loads of the effluent reached up to 25% and 17% of SLR, respectively, while chlorophyll a was up to 37%. The upstream-downstream evaluation showed an increase in dissolved phosphorus and chlorophyll a. The effluent phytoplankton (14.16 mm L) was dominated by organisms < 10 μm and diatoms (91%), and 3% of cyanobacteria. Cyanobacteria were not detected in SLR, though it appeared downstream of the effluent discharge. At the end of the bioassay, cyanobacterial biomass became the dominant group (37%). This study shows the potential development of cyanobacteria present in industrial effluents when diluted in river water. The effect of phytoplankton discharge from stabilization ponds is not generally considered in monitoring assessments and environment management, despite representing a particular risk if the water body is used as a drinking water source.
为乌拉圭供水的主要饮用水源（圣卢西亚河，SLR）于 2013 年受到了威胁，因为大量蓝藻水华顺着水流被输送到了水处理厂，而该水处理厂为这个国家一半的人口提供用水。位于河流流域的几个富营养化水库和稳定化池塘可能是蓝藻种群的来源。这种情况在生产力高的流域可能很常见；然而，很少有研究评估来自废水稳定化池塘的微藻对河流及其下游生存能力的影响。通过对 SLR 进行营养物和叶绿素 a 负荷、浮游植物组成以及废水在河水中的孵育等方面的研究，评估了乳制品废水对 SLR 的影响，以评估蓝藻潜在的发展。废水的总磷和总氮负荷分别达到了圣卢西亚河的 25%和 17%，而叶绿素 a 则达到了 37%。上下游评估显示溶解磷和叶绿素 a 增加。废水中的浮游植物（14.16 mm L）主要由 <10 μm 的生物和硅藻（91%）组成，还有 3%的蓝藻。尽管在废水排放口下游出现了蓝藻，但在圣卢西亚河中并未检测到蓝藻。在生物测定结束时，蓝藻生物量成为优势群体（37%）。本研究表明，当工业废水中的蓝藻在河水中稀释时，它们具有潜在的发展能力。尽管如果水体被用作饮用水源，这代表着一个特殊的风险，但稳定化池塘中的浮游植物排放对监测评估和环境管理的影响通常未被考虑。
