| With thecontinuous development of social economy and accelerating urbanization,China’s urban garbage and sewage sludge production are also increasing.There are morethan200being surrounded by garbage among600cities, China has become one of themost serious nationswith waste issue. At the end of "Eleventh Five-year" harmlesssludge disposal rate of urban sewage is less than25%.The waste and sludge withouttreatmentcontained large amounts of pathogenic microorganisms, heavy metals andother pollutants could contaminate environment. Therefore, the harmless treatment,resourcesutilization, and reduction of waste and sludge have become urgent issuesofenvironmental protection.The Integration reactor collaborates the garbage and sludge disposal at the sametime，which can achieve the goal of the harmless treatment, resourcesutilization, andreduction for waste and sludge. The paper developed pilot test equipment on the basis ofthe small pilot plant and tested as follows: started the test of the equipment forintegrating sludge digestion and waste disposal, developed a pilot scale test system inDadukou sewage plant and used the excess sludge tostudy the boot process equipmentby monitoring the temperature, moisture content, VFA, COD, VS/TS, alkalinity andother indicators of the device during startup;To examine the treatment effect in the testequipment and determine the optimal condition, respectively monitored the temperature,moisture content, VFA, COD, VS/TS, alkalinity and other indicators of operatingconditions as the dosing ratio in10%,15%,20%,25%.Finally, the bio-diversity in thereactor has been investigated by the PCR-DGGE technology. Made the followingfindings:①The sludge positions the start of the vaccination, and the heat production ofwaste composting can ensure thedesired temperature for sludge mesophilic digestion. onthe final stage of start-up the temperature has reached more than45℃which caneffectively kill pathogens,ascaris and other harmful organisms in garbage. Into the mudmoisture content in the reactor is between94%~99%, and the moisture content of themudis between87%~91%, which indicates the reactor had a good effect. Also,theremoval ofVS/TS maintained at about15%which shows organic matter somehow hasbeen degraded in the reactor. Meanwhile the pH of sludge positions maintained at7.0inthe latter, and alkalinity, VFA, SCOD, gas production as well as other indicators were in the normal range and relatively stable, which means the reactor has been successfullystarted.②The running test was taken a15%,20%,25%sludge dosing rate.During the test,the sludge position temperature keptin the range of25℃~40℃, and mostlyis above30℃, which basically meet the desired temperature for digestion.However, the largedeviation of temperature affected by the environment could result in inhibiting effect forgasing activity of methanogenic bacteria. In the three test conditions, the sludgepositions’ VFA, alkalinity, pH, SCOD and other indicators are normal, which reveals thereactor is running well, and cultivate a favorable environment for microorganismreproduction in the sludge. Compared the moisture content, VS/TS andgas productionrate in the three conditions, the optimal dosing rate is20%. Detecting a component ofthe gas, wherein the high methane content was found, with a high energy value.③The microbial population diversity in the reactor has been investigated byPCR-DGGE technology. The bands of the PCR-DGGE patters of the sludge in thereactor are very clear and bright, witch illustrate the system contain a large number ofmicroorganisms. Analysis of PCR-DGGE bands, we found that microorganisms insidethe reactor appeared some differences and continuity. At last we confirmed the optimaldosing is20%by analyzing richness and Shannon-wiener of different Samples indifferent working conditions. |
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