Scaglia Barbara, Adani Fabrizio
Dipartimento di Produzione Vegetale - Università degli Studi di Milano - Via Celoria 2, 20133 Milano, Italy.
Sci Total Environ. 2008 May 1;394(1):183-91. doi: 10.1016/j.scitotenv.2008.01.023. Epub 2008 Feb 15.
The organic matter contained in municipal solid waste (MSW) and in the MSW fractions obtained by mechanical separation has strong environmental impact when the waste is used as landfill. This is partly due to the biological activity that occurs under anaerobic conditions. Negative effects on the environment include unpleasant odors, biogas, leachate and biomass self-heating. Measuring the biological reactivity of waste with the help of indicators is an important tool to prevent waste impact. The aim of this study was to develop an index capable of describing the aerobic reactivity of waste, using both biological and chemical indicators. To develop this index, 71 MSW and MSW-product samples, including biologically treated MSW and mechanically separated MSW fractions, were analyzed. Fifty of the 71 samples analyzed represented MSWs and their derived products collected from a number of Italian waste plants and sites. The remaining 21 were MSW samples collected at different times during 8 different full-scale aerobic biological processes in four treatment plants used to reduce the biological reactivity of wastes. Five of these processes used the entire (unsorted) MSW, while the remaining three used the organic fraction of the MSW obtained by mechanical pre-treatment (waste sieving). Respirometric activity (Dynamic Respiration Index, DRI) and eluates characterization (chemical oxygen demand--COD, and 5 days biological oxygen demand--BOD5) were used as indicators of waste strength, as they had previously been reported to be indirect measures of waste impact on landfill. Summarizing all studied indicators, Principal Component Analysis (PCA) was used to develop the Putrescibility Index (Ip). The results revealed Ip index of 204+/-33 (mean+/-standard deviation) and 159+/-14 for the organic fraction of MSW and MSW untreated waste respectively, and of 106+/-16 and 101+/-22 for the corresponding biologically treated waste.
城市固体废物（MSW）以及通过机械分离得到的MSW组分中所含的有机物质，在用作填埋时会对环境产生强烈影响。这部分是由于在厌氧条件下发生的生物活性。对环境的负面影响包括难闻的气味、沼气、渗滤液和生物质自热。借助指标来测量废物的生物反应性是防止废物产生影响的重要工具。本研究的目的是利用生物和化学指标开发一种能够描述废物好氧反应性的指数。为了开发该指数，分析了71个MSW和MSW产品样本，包括经过生物处理的MSW和机械分离的MSW组分。所分析的71个样本中有50个代表从多个意大利废物处理厂和场地收集的MSW及其衍生产品。其余21个是在四个用于降低废物生物反应性的处理厂的8个不同全规模好氧生物过程的不同时间收集的MSW样本。其中五个过程使用了全部（未分类）的MSW，而其余三个过程使用了通过机械预处理（废物筛分）获得的MSW有机组分。呼吸测定活性（动态呼吸指数，DRI）和洗脱液表征（化学需氧量——COD和五日生化需氧量——BOD5）被用作废物强度指标，因为之前有报道称它们是废物对填埋场影响的间接测量指标。汇总所有研究指标后，使用主成分分析（PCA）来开发可降解性指数（Ip）。结果显示，MSW有机组分和未处理的MSW的Ip指数分别为204±33（平均值±标准差）和159±14，相应的经过生物处理的废物的Ip指数为106±16和101±22。
