中国农村生活垃圾的产生量与物理特性分析及处理建议

摘要

中国农村生活垃圾对生态环境的污染日益严重,为给农村生活垃圾的管理提供相应的理论支撑和技术支持,促进"新农村"的建设,该文基于对西部6省18县59村580户农户的现场调研和全国25个省(市)128篇文献调研的数理统计,对中国农村生活垃圾的来源、产生率、产生量、组分、容重、可压缩性等特征进行了全面、系统的归纳总结与分析.结果表明:中国农村生活垃圾产生率介于0.034~3.000 kg/(人·d)之间,中位值为0.521 kg/(人·d),2014年产生量达到1.48亿t,具有来源广泛且分散、产率低、产量高、增长迅速、区域差异显著等特点.生活垃圾主要组分包括厨余类、灰土类、橡塑类和纸类,其湿基质量累计百分比达到了83.61%,区域差异显著;与城市生活垃圾组分相比,具有低厨余和金属、高灰土含量的特点,并逐渐趋于城市化.生活垃圾的容重介于40~650 kg/m3之间,平均值为263 kg/m3,可压缩性较好.根据生活垃圾特性,在实施"村收集-镇运输-县处理"管理模式的农村,建议采用压缩式中转站和垃圾车进行收运;在有条件的农村地区,可逐步开展垃圾分类收集,将厨余和灰土从生活垃圾中分离后就地消纳.%In recent decades, a huge accumulation of domestic waste has caused serious environmental contamination, including negative impacts on human health in rural areas of China. Generally, collection, transport, treatment and disposal of waste are usually considered as the most important stages of waste management, which are directly linked to waste generation and characteristics. So, it is difficult to optimize the design of the required infrastructures and facilities without an accurate estimation of the amounts and characteristics of domestic waste. Nevertheless, to date few studies have investigated the characteristics of domestic waste in the rural areas of China. The main purpose of our work is to provide reliable background information as a reference and guidance for the source classification, for recycling, and for the treatment and disposal of domestic waste in rural areas of China. A total of 580 households in 59 villages of 6 provinces in West China were surveyed and 128 questionnaires were reviewed, based on which, the generation and physical characteristics of domestic waste in rural areas of China were analyzed via statistic method and the comparisons between different regions, between urban and rural areas and between China and other countries. Results showed that the sources of domestic waste in rural areas of China mainly included catering, daily consumption (such as packages, residues and obsoleted daily goods), cleaning from public areas and agricultural production. The generation rate of rural domestic waste was 0.034-3.000 kg/d per capita in different regions with the median of 0.521 kg/d per capita. It is much lower than the generation rate in cities and other developed countries. The total generation reached up to 148 million tons in 2014 in rural areas of China. The rural domestic waste showed the characteristics of wide range of sources, low generation rate, high volume, good compressibility, rapid growth and significant regional differences. Rural domestic waste was mainly composed of kitchen waste, ash, plastics and rubbers and paper with a cumulative proportion of 83.61%. The composition of the rural domestic waste differed significantly from regions. The content of plastic/rubber gradually decreased from south to north in China; on the contrary, the ash waste increased. In recent decades, the contents of kitchen waste, paper, plastic/rubber increased with time but the contents of ash waste, brick/ceramic, wood and glass decreased. It is because the composition of domestic waste in the countryside was gradually becoming similar with that of municipal solid waste in the city. However, it still had lower contents of kitchen waste and metals while higher content of ash waste compared with those in cities. The bulk density of the domestic waste was 40-650 kg/m3 with an average of 263 kg/m3. Moreover, the compressibility of the RDW was very good. Based on the outcome of this research, compressed garbage trucks and transfer stations are suggested in the countryside where the centralized treatment and disposal in the local county has been developed. Furthermore, sorting collection is recommended to separate kitchen waste and ash at the source and then treat them on site. These recommendations can greatly relieve the loads of waste collection, transportation and disposal and ensure financial viability.