| With the continuous improvement of people’s living standard and continuous high-speed development of the city life, processing has become an important social problem now. However, there are a lot of organics can be used among garbage, therefore, to design an efficient garbage sorting device is the key to achieve solid waste recycling. In this paper, according to the density difference between the organic and inorganic substances in garbage, we designed a hydraulic grader, studied the effection of hydraulic separation, and the subsequent processing after making clear the composition of sortied garbage.The results showed that:(1) The garbage which size is less than30mm will be obviously sorted into upper, middle and lower layers in water more than lm of depth and stirring. The density of garbage in upper layer is less than water, mainly composed of organic kitchen waste, also contains some plastic, a small amount of paper and other rubbish; the density of garbage in intermediate layer is close to water, are in a suspended state, subject to a variety of small garbage powder; the density of garbage in lower density is greater than water, mostly composed of inorganic, also contains a small amount of paper, plastic, organics, and other garbage.(2) Factors affecting the sorting effect of experimental device designed are mixing time T, agitation speed r, and paddle number n. In the experimental device, as long as T>3min, r>120r/min, n>0can reach the purposes of sorting preliminary. After orthogonal experiment, when T=5min, r=240r/min, n=2, the sorting effect can be mostly optimized. At this point, floating garbage, suspended and dissolved garbage, sunk garbage respectively make up49%,4%,38%.(3) Each time the garbage separation will produce COD which does not exceed400mg/L in the water. The biodegradability of this sewage is very good, with an average of70%of COD can be activated by sludge aerobic aeration method purify. Wastewater will be recycled after processing, the basic process is sedimentation tankâ†'aerobic aeration tankâ†'secondary settling tank. The best settling time of sewage produced in garbage sorting process is30min, which can remove88%suspended solids. The aerobic aeration best stay time is4h. Collection paper scraps whose sedimentation is fastest in sewage settling process, can successfully make new paper.(4) After draining the floating garbage weighing, organic kitchen waste accounted for85%, degradable organic has been greatly enriched, which is suitable for composting. The appearance of composting product come from floating garbage are black soil particles, smell ordinary, in addition to trace plastic pieces there are no particle size greater than12mm, also there are no sundries which can seriously affect the manurial, and the main nutrient elements TN and TP in composting distribution are0.635%and0.382%, which are both much better compared with the traditional compost and national standard. Because of composed mainly by inorganic and plastic type, sunk garbage compaction density can easily reach national standard, in consistent with the common waste compaction conditions, it can save81.5%space, and the water quality index of leachate generated will be much better than the leachate generated by rubbish not sorted because of the less organic matter content, that also means that all the subsequent processing will be easier and cheaper.(5) The experimental apparatus and the subsequent processing is a new set of harmless, resources and reduction processing system whose core is hydraulic sorting, relative to traditional waste disposal, environmental requirements and the area is much lower, and can create some economic value. |
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