Instituto de Ingeniería, Universidad Nacional Autónoma de México, Coordinación de Ingeniería Ambiental, Circuito Escolar S/N, Edificio 5, Ciudad Universitaria, Delegación Coyoacán, México, D.F. 04510, Mexico.
Water Res. 2012 Oct 1;46(15):4770-82. doi: 10.1016/j.watres.2012.06.014. Epub 2012 Jun 28.
Helminth eggs are the most difficult biological parasites to inactivate in wastewater and sludge. In developing countries, in particular, they are present in high concentrations and are the cause of many diseases that impact seriously on the human population. The process conditions for affordable inactivation are very variable, leading to different inactivation efficiencies. Temperature, dryness, pH and the developmental stage of the eggs must be taken into consideration to achieve complete inactivation. The objective of this research was to study the inactivation of six species of larval and non-larval helminth eggs of medical importance in developing countries under controlled conditions of temperature, pH, dryness and contact time. Results showed considerable differences in inactivation conditions among helminth eggs and a high level of resistance was confirmed for the eggs of Ascaris lumbricoides and Ascaris suum. The appropriate conditions for inactivation of all types of eggs were found by applying combinations of pH, temperature and dryness. At 45 °C it was possible to inactivate all species with a pH of 5.3 and 90% dryness within 6 days. If alkalization was applied, a pH of 12.7 was sufficient over 19 days at the same conditions of dryness and temperature. From these results it is proposed that both Ascaris spp. and Taenia solium may be used as indicators of biological contamination in wastewater and sludge.
寄生虫卵是最难在废水和污泥中灭活的生物寄生虫。特别是在发展中国家，寄生虫卵的浓度很高，是许多影响人类健康的疾病的根源。负担得起的灭活过程条件变化很大，导致灭活效率不同。为了实现完全灭活，必须考虑温度、干燥度、pH 值和卵的发育阶段。本研究的目的是在温度、pH 值、干燥度和接触时间的控制条件下，研究六种具有医学重要性的幼虫和非幼虫期寄生虫卵的灭活情况。研究结果表明，在寄生虫卵之间的灭活条件存在显著差异，并且确认了蛔虫和猪蛔虫卵的高抗性。通过应用 pH 值、温度和干燥度的组合，可以找到所有类型的卵的适当灭活条件。在 45°C 时，pH 值为 5.3 和 90%干燥度下，可以在 6 天内灭活所有物种。如果进行碱化，在相同的干燥度和温度条件下，pH 值为 12.7 时，19 天内即可满足要求。根据这些结果，建议使用蛔虫属和带绦虫作为废水和污泥中生物污染的指示物。
