【作者】 郝利峰；

【导师】 孙向阳；

【作者基本信息】 北京林业大学 ， 土壤学， 2012， 硕士

【摘要】 随着城市园林绿化面积的不断的扩大,园林绿化废弃物所造成的城市污染问题也越来越受到人们的关注。高温好氧堆腐技术处理园林绿化废弃物是实现资源化、无害化的一种有效方式。但是园林绿化废弃物堆腐过程中释放的恶臭气体难以达到国家规定的排放标准,成为制约堆腐化处理工艺规模化、产业化发展的重要因素。针对这一问题,我们以北京市香山公园春季修剪的剪枝和枯落物为堆腐原料,对其堆腐过程中产生的H2S和NH3气体展开研究,设置箱式高温好氧堆腐试验,探究园林绿化废弃物堆腐过程中H2S和NH3气体的释放规律,与不同物料C/N比、温度、pH值、通风状况和添加生物除臭菌剂等影响因子之间的关系,研究控制H2S和NH3气体释放的策略。研究结果如下：(1)不同物料C/N比影响堆腐过程中高温期的出现天数和持续时间,C/N为30的处理高温期的出现天数最短,在堆腐第3d就达到了65℃的最高堆温,55℃以上的堆温持续时间最长,持续了12d；影响堆腐过程中pH和EC值的变化和产品的最终pH和EC值。C/N为30的处理pH和EC值在整个堆腐过程中变化幅度明显,C/N为40的处理堆腐产品pH值最低,C/N为30的处理堆腐产品的EC值最低。(2)不同物料C/N比影响堆腐过程中C/N比的下降率、堆腐产品的C/N比和T值。C/N比为20的处理堆腐产品的C/N最低,C/N为30的处理C/N下降率最大,T值最小,且小于0.6。影响堆腐产品的种子发芽率指数。C/N为20的处理种子发芽率指数为78.88%,表明未腐熟；C/N为30的处理为98.47%,表明腐熟完全；C/N为40的处理为81.82%,表明基本腐熟。(3)不同物料C/N比影响堆腐过程中H2S气体和氨气的释放浓度和累积释放量。物料C/N比越低,两种气体释放量越大。H2S气体的释放规律是堆腐升温期先升高后下降,高温期前期上升,后期略有下降,降温期再上升,累积释放量的规律是高温期>降温期>升温期,因此对H2S气体的控制措施可集中在高温期和降温期进行；氨气的释放规律是堆腐升温阶段不断升高,高温期先达到最高峰值后逐渐下降,降温期下降并趋于平缓,累积释放量的规律是高温期>升温期>降温期,对氨气的控制措施可集中在升温期和高温期进行。(4)不同通风时间影响堆腐物料的腐熟情况和H2S气体和氨气的释放浓度和累积释放量,通风时间长,不利于物料的升温,达到完全腐熟所需的时间较长,且易造成H2S气体和氨气的集中释放；通风时间短,物料升温效果较好,达到完成腐熟所需的时间短,且H2S气体和氨气释放缓慢,累积释放量低。(5)添加生物除臭菌剂既可降低园林绿化废弃物堆腐过程中H2S气体的释放浓度和累积释放量,同时可提高堆腐产品的腐熟质量。(6)回归分析可得,园林绿化废弃物堆腐处理过程中物料的pH值与H2S气体的释放浓度呈显著正相关,与氨气的释放浓度呈显著负相关。因此,要使堆腐过程中H2S和氨气的释放量最低,则必须调节物料pH值。更多还原

【Abstract】 As the increasing of city’s landscaping area, people are more and more paying attention to city pollution caused by the landscaping wastes. Using high-temperature aerobic composting technology to dispose landscaping wastes is an effective way to achieve resource recovery and safety disposal. But the obnoxious gas generated by composting process by landscaping wastes can’t meet the regulated effluent standard of the country, which are becoming important factors in holding back the development of mass-production and industrialization of composting technology. To solve this problem, we conducted researches on H2S and NH3discharged by the landscaping wastes composting process, performed the box-type thermophilic aerobic composting experiments, explored the discharge rules of H2S and NH3during the process of landscaping wastes composting and the relationship with impact factors C/N, temperature, pH, ventilation, and biological deodorization bacteria, and studied ways to control H2S and NH3discharge. These activities were performed in Beijing Fragrant Hill Park using prunings and litter as composting target. The results are as follows:(1) Different C/N have impact on megathermal period days and duration. The megathermal period is the shortest when C/N is30, and the highest temperature65℃of the compost is appeared at the third day, and it has the longest duration period of12days at the temperature of above55℃. The C/N can also affect the pH and EC rangeability and the final value of pH and EC of the compost. The rangeability of pH and EC is obvious when C/N is30during the composting period and it has the lowest EC in dealing with the composting products, and the pH is the lowest when C/N is40.(2) Different C/N of composts have impact on the decline of C/N during the composting process, the product’s C/N, and the value of T. The compost’s C/N is the lowest when the C/N is20, and it has the largest rangeability and smallest value of T, which is less than0.6, when C/N is30. It also affects the seeds’ germination index. It has a germination index of78.88%for the seeds when C/N is20, indicating not decomposed yet; it has a germination index of98.47%when C/N is30, indicating totally decomposed; it has a germination index of81.82%when C/N is40, indicating mainly decomposed.(3) Different C/N have an effect on release concentration and cumulative release amount of H2S and ammonia during the decomposting process. The lower C/N for the compost, the more H2S and ammonia discharged. The rules of the H2S discharge are that rise at the beginning then decline at the warming up phase, rise at the beginning then slightly decline in the megathermal period, and rise to the highest in the catathermal period. The laws of the accumulative release amount is megathermal period> catathermal period> warming up phase, so the H2S control measures can be concentrated in the megathermal period and catathermal period. The rules of ammonia discharge are that rise continuously at the warming up phase, rise to the peak then decline gradually during the megathermal period, and decline to flat during the catathermal period. The laws of the accumulative release amount is megathermal period> warming up phase> catathermal period, and ammonia control measures can be concentrated in the megathermal period and warming up phase.(4) Different ventilation time affect the product’s condition of composting and the release concentration and accumulative release amount of H2S and ammonia. If the ventilation time is long, it will cause the discharge of H2S and ammonia at the same time and take longer time to achieve totally decomposed; if the ventilation time is short, it will take shorter time to become totally decomposed and make the discharge of H2S and ammonia a slower pace with a low accumulative release.(5) Adding biological deodorization bacterium agent can not only lower H2S accumulative release during landscaping wastes decomposting process, but also reduce the total discharge amount to a level lower than samples without handling.(6) The pH is positively correlated with the release concentration of H2S and negatively correlated with the release concentration of ammonia during the landscaping wastes decomposing disposal process. Therefore, the ph value must be adjusted to make the emission of H2S and NH3reach the lowest point.更多还原