基于电子鼻和GIS的大型生活垃圾堆肥厂恶臭污染源测定

    Determination of odour emission at compost plant based on electronic nose and GIS

    • 摘要: 堆肥能够在有效地处理有机生活垃圾的同时生产肥料产品,但堆肥过程中产生的恶臭气体是影响环境的重要因素,严重影响了该项技术的推广应用。为确定堆肥厂恶臭来源和强度,进而为进一步治理提供参考。笔者通过先期调查对堆肥厂存在的恶臭污染释放点进行了初步确定,利用GPS(global position system)定位技术进行网格化布点。在为期30 d的调查过程中,通过电子鼻检测手段分别对堆肥厂厂区和周边环境的恶臭污染状况进行检测。在获得大量现场检测数据的基础上选择GIS(geographic information system)技术中的张力样条法对调查区域进行插值运算,依据生成的数值绘制该区域恶臭污染的等强度曲线。通过作图能够直观地了解恶臭污染分布及浓度梯度下降趋势。对厂区的调查结果作图表明在堆肥厂厂区主要存在着2个主要的恶臭污染释放点源,一个位于发酵车间前段渗滤液抽排外运出口,电子鼻检测数值显示2465,另一个位于与生物滤池附近,电子鼻检测数值显示2913,通过折算臭气浓度分别为840和2191。其中发酵车间附近渗滤液抽排外运出口的取样点邻近与填埋场划定的厂界,其数值远远超过恶臭污染排放标准(GB14554-1993)规定的无组织排放厂界臭气浓度值。2个污染释放源的恶臭强度均达到5级水平。通过对周边环境的更大范围内的恶臭状况检测与比较分析,可以确定堆肥厂的恶臭污染是影响周边环境的首要恶臭因素。

       

      Abstract: Abstract: Three main styles of treatments used in the municipal solid wastes treatment process are compost, landfill and incineration. Composting is an effective treatment for organic solid waste to produce fertilizer. But it always produces a certain amount of leachate and gaseous pollutants during the process, which induces odorous nuisance problems. The malodorous gas produced during composting is an important factor affecting the environment, which often lead to complaints by residents from surrounding area and has negative effect on application of composting technology in municipal solid waste disposal. The odour emission problem from composting plant must be considered carefully.In the research, sampling locations were selected near to the odour pollution sources in a large scale running compost plant (treated more than 1000 tons rubbish per day) by preliminary investigations and GPS (global position system) technology which was used to grid distribution of test points in the research area. The odour concentration were measured at the place neared the emission points of the plant and at sampling sites in the downwind and upwind directions of the facilities by electronic nose under normal weather conditions during 30 days of the research period. Based on large amounts of data obtained at the test points in the area during the research period, tension spline interpolation method of GIS technology was used to calculate the values of the points that have not been tested on the odour emission direction. Then intensity curve of odour pollution in the region was plotted based on the values generated from GIS software. It can be intuitively understood the distribution and concentration gradient downward trend of odour pollution from emission points of composting plant.Two major odour release points were found at the composting plant from the odour intensity distribution map. One point located near fermentation workshop of the plant, intensity value measured by electronic nose was 2465. The other point located near the biofilter of the plant, intensity value measured by electronic nose was 2913. Odor concentration of the points were calculated by formula were 840 and 2191 respectively. The value of the sampling point at leachate drainage outward export that near fermentation workshop was far more than boundary concentration values of unorganized emissions that emission standards for odor pollutants (GB14554-1993) specified. The pollution intensity level of two odour release points reached five, and their concentration in air is normally far above the threshold limit value. There also had some odour escape in sorting workshop of the composting plant during research period.It is determined that the composting plant is prime odour released point that affected the surrounding environment by detection and comparative analysis of the odour concentration data on a wider region of surrounding area near the composting plant. The biofilter is the main odour pollution sources of composting plant. The results show that it is difficult to decrease the odour pollution of composting plant only by using biofilter at the last step to treat the waste gas which collected during whole composting process.

       

    /

    返回文章
    返回