石灰投加与搅拌对生态厕所的灭菌效果

以发展中国家农村地区的卫生条件改善为目的,开展了简易生态厕所的粪便堆肥处理实验。在投加石灰作为抑菌剂的条件下,研究了搅拌混合对杀灭致病微生物的影响,以及使堆肥终产物达到可接受风险值所需的最佳搅拌条件。实验确定了石灰的投加量,并应用Beta-Possion模型对堆肥处置过程中致病微生物对暴露人群的健康风险进行评价,从而从健康风险控制的角度确定了最佳的搅拌次数。研究结果表明,石灰投加量约占堆肥干重1.5%,手动搅拌50次,经搅拌后放置12 h能达到可接受的风险值(3.2×10-5)。

Effect of lime addition and mixing on pathogen inactivation in a composting toilet

In order to improve the sanitary condition in rural area in developing countries,an experimental study was conducted on feces treatment using a simple composting toilet with lime addition and manual mixing.The objective was to find the optimal condition for reducing the pathogenic risk to the acceptable level.The Beta-Possion model was used for evaluating the health risk on exposure to the pathogens residual in the composting product.As a result,it is found that the acceptable infection risk of 3.2×10^-5 can be achieved under the conditions of lime addition to 1.5% of the total dry weight of the compost,manual mixing for 50 times,and reaction time for 12 h.