Departamento de Quimica, Universidad Autonoma de Guerrero, Guerrero, Mexico.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2010;45(1):2-13. doi: 10.1080/10934520903388517.
Forty-eight hours acute toxicity tests were employed with Daphnia magna and Lecane quadridentata to assess the influents and effluents of the seven most important wastewater treatment plants (WTP) in the state of Aguascalientes, Mexico, during the 2006 dry and rainy seasons. The WTP of the City of Aguascalientes treated 1948 Ls(-1). The remaining six plants treated wastewater in the range from 28 to 93 Ls(-1). Plants efficiently removed toxicity when Daphnia magna was used as a model organism, but performed poorly when the freshwater rotifer Lecane quadridentata was employed. It was observed that biochemical oxygen demand (BOD(5)), chemical oxygen demand (COD), conductivity, dissolved oxygen (DO), pH, phenol, methylene blue active substances (MBAS), temperature, and total suspended solids (TSS) were within the maximum allowed levels (MAL) in the effluents during the rainy season. Whereas the BOD(5), total nitrogen, total dissolved solids (TDS) and TSS showed levels greater than the MAL in effluents during the dry season. The levels of BOD, MBAS, and total nitrogen were greater than the MAL in influents. In contrast, the values of TDS and TSS in influents were above the MAL during the rainy season. In the dry season the levels of aluminum (Al), iron (Fe), zinc (Zn), manganese (Mn), chromium (Cr), mercury (Hg) and lead (Pb) in influents and Fe, Mn and Pb in effluents were above the MAL. During the rainy season the levels of Mn, Cr and Hg in influents and those of Mn in effluents were above the MAL. When D. magna was used as model organism, acute toxicity units (aTU) for influents ranged from 0.2 to 4.4 and from 0.1 to 0.2 for effluents. These values for effluents are acceptable according to international guidelines. However, when L. quadridentata was the model organism, ranges were from 2.0 to 8.3 aTU in influents and from 1.6 to 2.6 aTU in effluents. The treated water that discharges into the San Pedro River would be considered toxic. The results of the toxicity tests demonstrated that the freshwater rotifer Lecane quadridentata was more sensitive (in 89.3% of the samples) than the cladoceran Daphnia magna when both organisms were exposed to the influents and effluents of the wastewater treatment plants.
采用大型溞和四角盘藻对墨西哥阿瓜斯卡连特斯州七个最重要的废水处理厂（WTP）的进水和出水进行了 48 小时急性毒性试验，评估了它们在 2006 年旱季和雨季的情况。阿瓜斯卡连特斯市的 WTP 处理了 1948 升/秒。其余六个工厂处理的废水量在 28 到 93 升/秒之间。当使用大型溞作为模式生物时，这些工厂有效地去除了毒性，但当使用淡水轮虫四角盘藻时，效果不佳。结果表明，在雨季，生化需氧量（BOD5）、化学需氧量（COD）、电导率、溶解氧（DO）、pH 值、苯酚、亚甲基蓝活性物质（MBAS）、温度和总悬浮固体（TSS）均在出水的最大允许水平（MAL）以内。而在旱季，BOD5、总氮、总溶解固体（TDS）和 TSS 的水平高于出水的 MAL。进水的 BOD、MBAS 和总氮的含量高于 MAL。相比之下，雨季进水的 TDS 和 TSS 含量高于 MAL。旱季进水的铝（Al）、铁（Fe）、锌（Zn）、锰（Mn）、铬（Cr）、汞（Hg）和铅（Pb）以及出水的 Fe、Mn 和 Pb 的含量高于 MAL。雨季进水的 Mn、Cr 和 Hg 以及出水的 Mn 含量高于 MAL。当大型溞作为模式生物时，进水的急性毒性单位（aTU）范围为 0.2 到 4.4，出水的范围为 0.1 到 0.2。这些出水的 aTU 值符合国际指南的要求。然而，当四角盘藻作为模式生物时，进水的范围为 2.0 到 8.3 aTU，出水的范围为 1.6 到 2.6 aTU。排入圣佩德罗河的处理水将被认为是有毒的。毒性试验的结果表明，当两种生物都暴露于废水处理厂的进水和出水时，淡水轮虫四角盘藻比甲壳类动物大型溞更为敏感（在 89.3%的样本中）。
