广东省农村无害化卫生厕所效果评价

Effect Evaluation on Non-hazardous Latrine in Rural Areas of Guangdong Province

目的调查2011年广东省无害化卫生厕所建造和使用情况,评价其对粪便处理的卫生效果,为指导广东省农村改厕工作提供科学依据。方法按分层整群抽样的方法,在全省随机抽取3个县,每个县随机调查3个改厕村和3个未改厕村,每村随机抽取30户,现场勘察三格式化粪池考察其建造是否符合要求。随机采集45座无害化卫生厕所和非卫生厕所粪液样品,实验室检测粪大肠菌群(FC)、寄生虫卵、化学需氧量(CODcr)、氨氮(NH3-N)、硝酸盐氮和亚硝酸盐氮等指标。计算进、出口FC的平均合格率,寄生虫卵检出率、CODcr、NH3-N、硝酸盐氮和亚硝酸盐氮平均去除率。结果在调查指标中,改厕户的合格率明显高于未改厕户。135份粪液样品中,卫生厕所进、出口及非卫生厕所FC平均合格率分别为93.33%、100%和86.67%,寄生虫卵检出率分别为55.56%、4.44%和51.11%,出口CODcr、NH3-N、硝酸盐氮和亚硝酸盐氮平均去除率分别为58.02%、42.93%、34.08%和85.00%。结论 2011年广东省无害化卫生厕所的无害化处理效果明显,其对粪便中FC和寄生虫卵有很好的杀灭作用,但对CODcr、NH3-N、硝酸盐氮和亚硝酸盐氮的去除效果不够理想,需做进一步处理。

Objectives To investigate the latrine improvement in rural areas of Guangdong Province in 2011 and evaluate the effect of the non-hazardous treatment of the septic tank so as to supply the evidence for policy- making. Methods Three counties were randomly chosen through stratified cluster sampling in the whole province. And three latrine improvement villages and three non-latrine improvement villages were randomly chosen in each survey county, and in each village 30 families were randomly chosen and surveyed. Meanwhile, the samples were collected from the inlet and outlet of 45 ＂ three-grille mode＂ septic tanks. The parasite eggs, chemical oxygen demand（CODer） , nitrate nitrogen, nitrite nitrogen, ammonia nitrogen （ NH3 - N） and fecal coliform （ FC ） were tested in lab. The quality rate of FC, detection rate of parasite eggs, removal rates of CODer, nitrate nitrogen,nitrite nitrogen and NH3 - N were calculated. Results During these septic tanks, the construction quality pass rate of latrine improvement families was significantly higher than those of non-latrine improvement families. In the 135 samples, the mean quality rates of FC in the inlet, outlet of the septic tank and non-sanitary latrines were 93.33%, 100% and 86.67%, respectively. The detection rate of parasite eggs were 55.56%, 4.44% and 51.11% , respectively. The mean removal rates of CODer, NH3 - N, nitrate nitrogen and nitrite nitrogen of the septic tank were 58.02% , 42.93% , 34.08% and 85.0% , respectively. Conclusions In 2011, the effect of nonhazardous latrine in Guangdong Province was obvious,which had a good effect of destroying FC and parasite eggs. However,the removal abilities of CODcr, NH3-N, nitrate nitrogen and nitrite nitrogen are non-ideal and should be further conducted.