| Objectives:The development of sanitary toilets and nonhazardous disposal of excreta can effectively prevent the occurrence of intestinal infection and parasite diseases and improve the sanitization of environment and healthy standard and living quality of people in rural area.Recent research mainly focused on survey of current status and hygiene evaluation of traditional sanitary toilets,such as the biogas sanitary toilet,the traditional three-chamber sanitary toilet.There are no many publicly available studies on the effects of urine diverting toilets,the outcome of manual covering materials,and comprehensive benefits of rural ecological sanitary toilets.Therefore,the objectives are three-fold.First,we evaluated the outcome of non-hazardous disposal of urine diverting ecological sanitary toilet used in rural areas and influence factors to provide guidelines for later popularization.Second,we studied the covering materials used in urine diverting ecological sanitary toilets and influence factors and compared the effects of different covering materials.Third,we analyzed the health,ecological,and social benefits of rural ecological sanitary toilets,such as the biogas sanitary toilet, the urine diverting ecological sanitary toilet and the traditional three-chamber sanitary toilet,in terms of disease control,ecological circulation,and environmental protection.We then compared the benefits of different modes of toilets transformation,to provide guidelines for rural toilets transformation and other public sanitary work and to promote sustainable economic,social,and ecological development in rural areas.Methods:1.We selected 25 households in Xingfupo of Tiantang Village,Nuwanzhongpo of Wuhe Village,Yongning County,Nanning City,and 20 households in Xiananzhou of Nanzhou Village,Diecai District,Guilin City.Toilets penetration rate in these areas is 100%.We required participants to use toilets in compliance with related regulations and not to unclose toilets before the end of this survey.We then collected one sample in each household in the second, third,sixth,eighth,and the twelfth month.We monitored the usage and maintenance of urine diverting toilets and hygiene metrics,such as pH value,moisture,value of escherichia coli,odor,insects and flies based on field survey and lab test.We then performed hygiene evaluation according to the Hygienic Standards for Excreta Sanitization GB 5759-87.2.Based on concrete status and requirement of farmers,we selected three study sites:Xingfupo of riantang Village,Nuwanzhongpo of Wuhe Village,and ruanyanpo of Dingxi Village,Yongning County,Nanning City.Urine diverting toilets are used in these sites.We further selected 21,42,and 27 households in these sites respectively.Each group used man-made covering material #1,#2,and plant ash as covering material.We then collect one sample in each participant home in the second,third,sixth,and the eighth month.We learn the usage and maintenance by questionnaire and field survey.We test the value of escherichia coli,PH value, moisture,odor,insects and fliesin the lab and make evaluation according to the Hygienic Standards for Excreta Sanitization GB 5759-87.3.Based on geological and climate condition and concrete status and requirement of farmers,we selected Gongcheng,Yongning, Wuming,Beiliu,Guilin,Longan,Pubei,Pingguo,Yulin,Guigang in Guangxi as monitor sites.We in total investigated 340 three-chamber sanitary toilets,640 biogas sanitary toilets and 380 urine diverting ecological sanitary toilet.We collected documents and performed field survey.We comprehensively analyzed the investment of the three different types of toilets,the structure of investment,and investment mechanism,water-saving, energy-saving,forestation,rate of people who know health knowledge, rate of health behaviors,and other criteria.We do not repeat tests results of which are determined and are publicly accepted.Results:1.We monitored the usage and maintenance of urine diverting toilets and hygiene metrics,such as pH value,moisture, value of escherichia coli,odor,insects and flies based on field survey and lab test.The results were that:(1)in the 45 monitored farmer households,toilets with bare smell accounted for 91.1% (41/45),toilets almost without fly 88.9%(40/45),toilets without insect 73.3%(33/45)The results showed that maintenance of toilets in monitored farmer households was good and rates of all metrics were above 70%.(2)In Yongning,the qualification rate of value of escherichia coli is 20.0%(5/25),80.0%(20/25),92.0%(23/25), 100%(25/25),100%(25/25)respectively in the second,third,sixth, eighth,and twelfth month.In Guilin,the rate is 15.0%(3/20),75.0%(15/20),85.0%(17/20),95.0%(19/20),100%(20/20)respectively. The rate is 17.8%(8/45),77.8%(35/45),88.9%(40/45),97.8%(44/45),100.0%(45/45)respectively.These results demonstrate that excreta in over 75%of toilets can become non-hazardous after 3 months.(3) There was no significant difference of the qualification rate of value of escherichia coli between the two sites after 3 months (calibration X2=0.0016,P=0.9680).(4)In all monitored toilets,8 toilets reached the sanitary standards after 2 months in terms of value of escherichia coli,and 27 toilets after 3 months.There were still 5 toilets that did not reach the standard after half a year and where pH was less than 9 and dung dregs moisture was greater than 35.The pH of toilets where non-hazardous disposal of excreta perform well usually showed alkalescence.The minimum of dung dregs pH was 7.71 and the maximum was 10.77.Toilets with pH between 7.71 and 9.0 accounted for 28.6%and toilets with pH above 9.0 accounted for 71.4%.The range of dung dregs moisture fell in 11.44 and 69.5%with mean of 29.5%.The moisture decreased with time elapsing and the mean was 23.4%after 6 months.2.We also monitored the usage of covering material used in urine diverting ecological sanitary toilets and related influential factors to compare the effect of different covering materials.The results showed:(1)toilets with smell accounted for 6.7%(2/30)for plant ash,10.0%(3/30)for covering material #1,6.7%(2/30)for covering material #2;second,toilets with flies accounted for 10.% (3/30)for plant ash,16.7%(5/30)for covering material #1,13.3% (4/30)for covering material #2.Of 90 toilets,92.2%(83/90)were almost odorless,86.7%(78/90)almost without flies,75.6%(68/90) almost without insects.75%of all toilets met all criteria.This showed that the maintenance of farmer toilets was good.(2)The qualification rate of value of escherichia coli:23.3%(7/30),90.0%(27/30),96.7%(29/30),96.7%(29/30)for the group using plant ash,13.3%(4/30),83.3%(25/30),96.7%(29/30),96.7%(29/30)for the one using covering material #1,20.0%(6/30),93.3%(28/30),93.3%(28/30),96.7%(29/30)for the one using coveringmaterial #2.(3) There is no significant difference between the values of escherichia coli achieved by plant ash and covering material #1 respectively after 3 months(calibration:X2=1.4442,P=0.7041).The results are similar for the comparison between plant ash and covering material #2(calibration:X2=0.0000,P=1.0000)and the comparison between covering material #1 and covering material #2(calibration: X2=0.6469,P=0.4212).(4)PH:9.47 for plant ash,9.32 for covering material #1,and 9.30 for covering material #2.The range of water: 15.1%-60.3%,18.21%-55.6%for covering material #1,and 18.32%-54.0% for covering material #2。3.three-chamber sanitary toilets,biogas sanitary toilets as well as urine diverting ecological sanitary toilets can reach the hygienic standard of harmless excreta and show certain comprehensive benefits.(1)Firstly,biogas sanitary toilets can improve significantly the environmental and hygienic condition such as the effective management of excreta.Secondly,it can induce better ecological environment,for example,methane gas can replace firewood,protecting the vegetative cover,and nourishing water source,thirdly,high economic rewarding like沼液沼渣being used in cultivating trees,reducing the application of chemical fertilizer,methane gas reducing the usage of other energy sources, fourthly it can provide highly efficient organic fertilizer, improving the soil condition,fifthly,it can fully uses the original living space environment,sparing more space.(2)urine diverting ecological sanitary toilets can save huge amount of water,providing high efficient organic fertilizer,improving the soil condition, thus showing great ecological,heath,and social benefits.It can be applied safely in any place,such as one-storied house,apartment, share rented house,ordinary house,schools and offices,etc.Conclusion:1.urine diverting ecological toilets is a ecological sanitary toilet with broad application prospect for it is anti-fly,odorless,human excreta decontaminating, environmentally friendly,water saving and cheap.It especially suits the arid rural areas.2.man-made covering material #1,#2, and plant ash as covering material all can decontaminate excreta and show no difference in time usage,and can be used in the urine diverting toilet.3.All three toilets can meet the hygienic standard of decontaminating excreta and have certain comprehensive benefits,except that the urine diverting toilets show even higher ecological and comprehensive benefits,thus much more applicable for generalizing in different and broader areas. |
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