Lesser y Asociados, S.A. de C.V., Querétaro, Mexico; Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Mexico.
Centro del Agua para América Latina y el Caribe, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Mexico.
Chemosphere. 2018 May;198:510-521. doi: 10.1016/j.chemosphere.2018.01.154. Epub 2018 Feb 3.
The Mezquital Valley system is the world's oldest and largest example with regard to use of untreated wastewater for agricultural irrigation. Because of the artificial high recharge associated with the Mezquital Valley aquifers, groundwater is extracted for human consumption, and there are plans to use this groundwater as a water resource for Mexico City. Thus, this study analyzed 218 organic micro-contaminants in wastewater, springs, and groundwater from Mezquital Valley. Five volatile organic compounds (VOCs) and nine semi-volatile organic compounds (SVOCs) were detected in the wastewater used for irrigation. Only two SVOCs [bis-2-(ethylhexyl) phthalate and dibutyl phthalate] were detected in all the wastewater canals and groundwater sources, whereas no VOCs were detected in groundwater and springs. Of the 118 pharmaceutically active compounds (PhACs) and 7 reproductive hormones measured, 65 PhACs and 3 hormones were detected in the wastewater. Of these, metformin, caffeine, and acetaminophen account for almost sixty percent of the total PhACs in wastewater. Nevertheless, 23 PhACs were detected in groundwater sources, where the majority of these compounds have low detection frequencies. The PhACs sulfamethoxazole, N,N-diethyl-meta-toluamide, carbamazepine, and benzoylecgonine (primary cocaine metabolite) were frequently detected in groundwater, suggesting that although the soils act as a filter adsorbing and degrading the majority of the organic pollutant content in wastewater, these PhACs still reach the aquifer. Therefore, the presence of these PhACs, together with the high levels of the endocrine disruptor bis-2-(ethylhexyl) phthalate, indicate that water sources derived from the recharge of the studied aquifers may pose a risk to consumer health.
梅斯基特山谷系统是世界上历史最悠久、规模最大的未处理废水用于农业灌溉的系统。由于与梅斯基特山谷含水层相关的人为高补给，地下水被抽取用于人类消费，并且有计划将这些地下水用作墨西哥城的水资源。因此，本研究分析了梅斯基特山谷污水、泉水和地下水中的 218 种有机微量污染物。在用于灌溉的废水中检测到五种挥发性有机化合物（VOCs）和九种半挥发性有机化合物（SVOCs）。在所有的污水渠和地下水源中仅检测到两种 SVOCs [双（2-乙基己基）邻苯二甲酸酯和邻苯二甲酸二丁酯]，而在地下水中和泉水中均未检测到 VOCs。在所测量的 118 种药物活性化合物（PhACs）和 7 种生殖激素中，在废水中检测到 65 种 PhACs 和 3 种激素。其中，二甲双胍、咖啡因和对乙酰氨基酚占废水中总 PhACs 的近百分之六十。尽管如此，在地下水源中仍检测到 23 种 PhACs，其中大多数化合物的检测频率较低。磺胺甲恶唑、N，N-二乙基间甲苯酰胺、卡马西平、苯甲酰基可卡因（可卡因的主要代谢物）在地下水中经常被检测到，这表明尽管土壤作为过滤器可以吸附和降解废水中的大部分有机污染物，但这些 PhACs 仍会到达含水层。因此，这些 PhACs 的存在以及内分泌干扰物双（2-乙基己基）邻苯二甲酸酯的高含量表明，来自研究含水层补给的水源可能对消费者健康构成威胁。
