Studies of metal toxicity to microalgae have predominantly been conducted using single non-target algae species and without due regard for the chemistry of the treated waters, leading to ineffective or excessive algaecide treatments. In this study, indigenous multi-algal species (Scenedesmus quadricauda, and Scenedesmus subspicatus and Oscillatoria agardhii) were used in laboratory toxicity bioassays under simulated field water chemistry (pH = 7.2, hardness = 196 mg L⁻¹ as CaCO₃, and alkalinity = 222 mg L⁻¹ as CaCO₃) to determine the optimum copper sulfate treatment dose to control algae growth in an irrigation canal. Toxicity bioassays were conducted using copper sulfate in chelated (with EDTA) and non-chelated (without EDTA) forms to assess the influence of the use of synthetic chelators in toxicity studies. Also, copper toxicity to the indigenous algae species was measured in the non-modified EPA test medium (pH = 7.5, hardness = 92 mg L⁻¹ as CaCO₃, alkalinity = 10 mg L⁻¹ as CaCO₃ and EDTA= 300 µg L⁻¹) to assess the impact of the water chemistry on algae inhibitory algal dosages. Under simulated water chemistry conditions, lower toxicity was measured in the test flasks with the chelated form of copper (96 h- EC₅₀= 386.67 µg L⁻¹ as Cu) as compared to those with the non-chelated metal (96 h-EC₅₀= 217.17 µg L⁻¹ as Cu). In addition, higher copper toxicity was measured in the test flasks prepared with the non-modified EPA medium using chelated copper (96 h-EC₅₀ = 65.93 µg L⁻¹ as Cu) as compared to their analogous microcosms with modified water chemistry (96 h-EC₅₀= 386.67 µg L⁻¹ as Cu), the increased water hardness and alkalinity in the latter case contributing to the decrease of the metal bioavailability. Results from laboratory experiments showed good correlation with copper dosages used in a small scale field testing to control algae growth, increasing confidence in laboratory bioassays.

金属对微藻的毒性研究主要是使用单一非目标藻类进行的，没有适当考虑处理水的化学性质，从而导致无效或过量的除藻剂处理。在这项研究中，在模拟的现场水化学条件下（pH = 7.2，硬度= 196 mg L ^-1作为CaCO ₃，碱度= ），将本地多藻物种（Scendesmus quadricauda，Scendesmus subspicatus和Oscillatoria agardhii）用于实验室毒性生物测定。222 mg L ^-1为CaCO ₃），以确定控制灌溉渠中藻类生长的最佳硫酸铜处理剂量。使用螯合（含EDTA）和非螯合（无EDTA）形式的硫酸铜进行毒性生物测定，以评估使用合成螯合剂对毒性研究的影响。另外，在未经修饰的EPA测试介质中测量了铜对本地藻类的毒性（pH = 7.5，硬度= 92 mg L ^-1作为CaCO ₃，碱度= 10 mg L ^-1作为CaCO ₃，EDTA = 300 µg L ^-1）以评估水化学对藻类抑制藻类剂量的影响。在模拟的水化学条件下，使用螯合形式的铜（96 h-EC₅₀ = 386.67 µg L ^-1（铜），而非螯合金属（96 h-EC ₅₀ = 217.17 µg L ^-1铜）。此外，与使用改良水化学的类似微观世界相比，在使用非改性EPA介质，使用螯合铜（96 h-EC ₅₀ = 65.93 µg L ^-1作为Cu）制备的测试瓶中，铜的毒性更高（96 h-EC ₅₀ = 386.67 µg L ^-1（如铜），在后一种情况下增加的水硬度和碱度会导致金属生物利用度降低。实验室实验的结果表明，与用于小规模现场测试以控制藻类生长的铜剂量具有良好的相关性，从而增加了对实验室生物测定的信心。