| Present, our country is facing a huge crisis of environmental pollution and energy-resources, especially in the countryside, most of the sewage was discharged in water directly. In the existing way of sewage discharge, the human excrement and urine emmit into sewage pipes mixed, there are many erganic resources,like N P K, in the human’s excrement, this way of discharge will increase the difficulty of the sewage treatment, and cause the waste of nutrients. Through the source separation of ECOSAN toilet, the toilet sewage was separated into excrement and urine from the source, in this way,it could not only reduce the pollution load of wastewater, could also take advantage of nutrients which contained in the excrement and urine. Enentually, it could form an organic resources cycle in plant-human-waste-food-farm. In order to use the organic resources from huaman’s excrement and urine betterly, in this paper, we present a solution, which is a combination of the ECOSAN and drip irrigation technology. Through the source-separated toilet, we could separate the human’s excrement into faeces and urine, the urinal flushing water was streamed through the pipeline to the storage pool, stay in urine after the disposal of urea into ammonia, and than use it to drip irrigation on agricultural land.Centralized wastewater treatment systems can solve the environmental pollution which was caused by the rapid development of city to some extent, it also play an important rule to protect the environment with optimization,but because of its high costs and large energy comsumption, so, it is not a sustainable system. Decentralized wastewater treatment can colve the lack of centralized system to some extent, it have a good effect, lower investments and flexibility, but it is still unable to achieve the recycling of resources and energy, so, Decentralized wastewater treatment have not been effectively used, and not meet the requirements of sustainable development. In order to realize the sustainable development request, source-separated technology arises at the historic moment, it separate and use the feces and urine from the source, it have the characteristic of health security and can realize material recycling.According to statistics, we can get about25-50kg faecal excretion per person per year, calculation for the bottom line, it containes about0.55kg nitrogen,0.18kg phosphate and0.37kg of potash in25kg waste, and these are good farmland basal manure. Manure can been fermentated with other domestic organic garbage in dry and hot condition for some times, generally3-9months, its fermentation products can be applied to agricultural directly, can also be used with other compost products mixed. In human excrement, urine contians the most mutrients, according to statistics, in each of human excrement, what contain the nutrients such as nitrogen, phosphorus and potassium, urine contains about four-fifths cent of its content, manure accounted for about one-fifth. Urine can be used into nutritional components directly, although it may contain trace amounts of heavy metal, but these heavy metal concent is limited, which can basically be ignored. The urine for irrigation can not have high PH values, if PH value is too high, it can inhibits the hydrolysis of urea with decomposition, so, we can adjust PH value by injucting acetic acid. Urea ammonia, which is produced from the decomposition, is valatile, in order to reduce the wastage of resources caused by volatilization of ammonia-n, this study use the irrigation toreduce the effect of ammonia volatilization.In china, the agricultural production is mostly small family-run, it’s hard to form large-farm labor patterns, so, the urine drip irrigation is difficult to use in large areas, this system is mainly used for irrigation in the field near the village, and can also be applied to farmers’s own pastoral land. Urine collection relies mainly on manure separation type toilet and urinal flushing water pipeline, separation of urine into the pipeline, streamed to the urine collects through the pipeline, while gathering pipeline is combined with farmers’housing structure to design and install. The rural housing structure is relatively simple, and are mostly single family structure, in the design, it can be designed for both single-pipe systems, separate laying pipes, drip irrigation for their small courtyard irrigation. United pipeline systems can also be designed for a variety of household, close a few households will be connected by pipes. The urinal flushing water can set up joint irrigation for the using in the spare idle of village, which can significantly increase rural utilization effect of organic feiyuan, and reducing the cost per household. Urine is stored in large storage containers, in the urine, mainly contain various acids, sodium chloride and urea, one of the most important and most useful is urea, urea can be used as a nitrogen fertilizer for crops. But urea cannot be directly absorbed by crops, while high concentrations of urine will cause damage to the crop, so to take advantage of nutritional substances in the urine, first to dilute the urine, lowering its concentration of urea, to avoid excessive concentrations on crop damage. Urinal flushing water appears to be weakly alkaline degradation of, and some pathogenic microorganisms to survive in an alkaline environment should not be, hence the need for urinal flushing water storage for a certain amount of time in order to make the urine biologically harmless requirements are met. Powered using solar energy are first considered for drip irrigation, solar energy in rural areas is relatively abundant and clean and pollution-free in relation to the city. When the cloudy rainy weather lead to solar power is not sufficient to ensure the system, can switch to biomass energy by variable frequency control, using manure methane emitted energy to provide sufficient impetus for drip irrigation, so in this system, utilities can guarantee the normal operation of the system, no external power energy. In farmland irrigation, use urine alternating drip irrigation with water irrigation to ensure crop will not damage by drip urine for a long time.In this study, we also builde an engineering examples in a village, yishui Shandong province. It is a source-separated toilet, and located in the south of the village bazaar. Respectively for collecting feces with urine and manure for composting, managed by a village of specialized personnel. Urine is piped into greenhouses outside the village, through simple storage and treatment, used for low pressure drip irrigation in greenhouses. In this mode, it can nor only solve the environmental pollution which is caused by hunman excrement, but also can reduce water using, Eventually, the nutrients, such as nitrogen, phosphorus, potassium, can also be used in the recycling, and formed crop-human-plant closed loop. |
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