Economics analysis of food waste treatment in China and its influencing factors

• Economics of food waste treatment projects at 29 pilot cities in China was examined. • Roles of location, population size, processing technique, and income were studied. • Economic benefits were limited with a profit to cost ratio of 0.08±0.37. • Service population size affects construction economics significantly (P = 0.016). • Choice of food waste processing technique affects operating economics notably. This study examines the economic benefits of food waste treatment projects in China and factors affecting them. National-level pilot projects for food waste treatment located in 29 cities were selected as samples. The economics of food waste recycling from the investors’ perspective, in terms of investment during the construction phase and cost and benefit during the operation phase, was assessed. Results indicate that the average tonnage investment of food waste treatment projects was RMB 700.0±188.9 thousand yuan, with a profit to cost ratio of 0.08±0.37. This ratio increased to 0.95±0.57 following the application of government subsidies. It highlights the limited economic benefits of food waste treatment facilities, which rely on government subsidies to maintain their operations in China. Further analysis using a multi-factor analysis model revealed that regional location, service population size, processing techniques, and urban income exerted varying impacts on the economy of food waste treatment. Population size exerted the highest impact (P = 0.016) during the construction stage, and processing techniques notably influenced the project economy during the operation stage. The study highlights the need to prioritize service population size and processing techniques during economic decision-making and management of food waste recycling projects. The results of this study can serve as a valuable practical reference for guiding future policies regarding food waste treatment and related planning.     

提取七叶皂苷钠的废水处理

提取七叶皂苷钠废水中含有七叶皂苷钠、淀粉、色素、胶质。其中七叶皂苷钠易起泡,不易回收和处理,本文采用加抑泡剂(YP1),深度处理回收釜残液,使综合废水浓度降低,经水解酸化3h,好氧生物处理6h,出水CODCr<100mgL,达到国家规定的排放标准。     

湖州大钱港(溇港)河流生态缓冲带的划定与构建

河流生态缓冲带(后称"缓冲带")对改善河流水环境、控制面源污染和水土流失等具有重要作用。如何确定缓冲带的宽度并对其进行合理构建,已成为学者与管理部门关注的热点之一。以浙江省湖州市平原河网型河流大钱港(溇港)为例,基于VFSMOD模型计算和地形坡度、水体流向、土地利用状况、降水条件、土壤类型等现状条件,确定了农田型河段、村落型河段、林草型河段的缓冲带宽度;针对城镇型河段,结合城市河道蓝线,确定了缓冲带的宽度。结果表明,大钱港干流左右岸缓冲带长度共约16.1 km,面积共约0.408 km²;同时,采用GIS对数据进行处理,并实现了缓冲带的可视化表达。结合农业农村面源污染负荷空间分析,筛选出高污染入河负荷区中的唐家浒自然村汊港段,并提出了缓冲带修复方案,以期为其他缓冲带划定与构建提供参考。     

高浓度油田压裂废水降低CODCr的预处理方法

针对高浓度油田压裂废水黏度高、浊度大、含油量高等特点,强化预处理工艺,降低CODCr值。文章通过实验证明了强氧化剂(Fenton试剂)与混凝剂PAC+PAM相结合的工艺可有效降低高浓度含油废水CODCr值,进而通过Fenton试剂与混凝剂的投药量、pH值等因素对高浓度油田压裂废水的影响进行分析,得出采用该化学预处理方法出水水质清澈,可直接进入生化处理系统进行后续处理。     

公民环境信访行为影响因素的实证分析——基于规范激活理论

环境信访是中国公民环境利益表达的重要途径,也是其参与环境治理的重要通道,引导公民有序进行环境信访对于加强生态文明建设、深化环境治理、维护社会稳定具有重要意义。本研究从环境信访的参与主体——公民入手,基于社会心理学中规范激活理论的连续模型,构建了公民环境信访影响因素的理论模型,并运用AMOS 20.0对S市9个行政区500位市民的问卷调研结果进行实证分析,探究公民环境信访行为的社会心理影响因素。研究结果表明:规范激活理论的连续模型能够较好地解释中国公民的环境信访行为,其中环境信访结果认知正向影响环境信访责任归属,公民的个体规范需要通过责任归属得以激活,从而影响公民环境信访行为意向。因此,政府可以通过环保知识的宣传教育和完善环境信访相关法律法规来提升公民环保意识和环境信访责任归属感,同时可以通过环保政策法规的宣传、畅通环境信访渠道以及对公民环境信访行为的有效处理来促进公民对环境信访行为积极意义的认知,从而推动公民有序进行环境信访。     

Spatial and temporal variations of nitrous oxide flux between coastal marsh and the atmosphere in the Yellow River estuary of China

To investigate the spatial and seasonal variations of nitrous oxide (N₂O) fluxes and understand the key controlling factors, we explored N₂O fluxes and environmental variables in high marsh (HM), middle marsh (MM), low marsh (LM), and mudflat (MF) in the Yellow River estuary throughout a year. Fluxes of N₂O differed significantly between sampling periods as well as between sampling positions. During all times of day and the seasons measured, N₂O fluxes ranged from ?0.0051 to 0.0805 mg N₂O m^?2 h^?1, and high N₂O emissions occurred during spring (0.0278 mg N₂O m^?2 h^?1) and winter (0.0139 mg N₂O m^?2 h^?1) while low fluxes were observed during summer (0.0065 mg N₂O m^?2 h^?1) and autumn (0.0060 mg N₂O m^?2 h^?1). The annual average N₂O flux from the intertidal zone was 0.0117 mg N₂O m^?2 h^?1, and the cumulative N₂O emission throughout a year was 113.03 mg N₂O m^?2, indicating that coastal marsh acted as N₂O source. Over all seasons, N₂O fluxes from the four marshes were significantly different (p?<?0.05), in the order of HM (0.0256?±?0.0040 mg N₂O m^?2 h^?1)?>?MF (0.0107?±?0.0027 mg N₂O m^?2 h^?1)?>?LM (0.0073?±?0.0020 mg N₂O m^?2 h^?1)?>?MM (0.0026?±?0.0011 mg N₂O m^?2 h^?1). Temporal variations of N₂O emissions were related to the vegetations (Suaeda salsa, Phragmites australis, and Tamarix chinensis) and the limited C and mineral N in soils during summer and autumn and the frequent freeze/thaw cycles in soils during spring and winter, while spatial variations were mainly affected by tidal fluctuation and plant composition at spatial scale. This study indicated the importance of seasonal N₂O contributions (particularly during non-growing season) to the estimation of local N₂O inventory, and highlighted both the large spatial variation of N₂O fluxes across the coastal marsh (CV?=?158.31 %) and the potential effect of exogenous nitrogen loading to the Yellow River estuary on N₂O emission should be considered before the annual or local N₂O inventory was evaluated accurately.     

用自旋标记方法研究环境诱变剂对健康人红细胞膜动态性质的影响

健康人的完整血红细胞膜用脂肪酸自旋标记物Ⅰ(12,3)和Ⅰ(1,14)标记,测得其ESR波谱·氟化钠、重铬酸钾、丝裂霉素C和秋水仙素等环境诱变剂较显著地改变膜的序参数S和旋转相关时间,尤在膜表层,S和明显增大。温度曲线表明,人血的完整红细胞膜的相变点在膜表层和深层分别是38℃和40.0℃。在诱变剂作用下,膜类酯的动力学性质有明显变化。     

城郊菜园土污染状况调查与评价

南京市郊菜园土中Ａｓ、Ｈｇ、Ｃｄ、Ｐｂ四种元素的含量呈逐年上升趋势。除Ａｓ外，其余３种元素的含量均为土壤背景值的２￣３倍。综合评价表明，供试土样中约５０％以上的样点不再适宜种植蔬菜作物而只宜作林业用地或城建、道路及工矿用地。     

陕西关中地区水环境承载力研究

从水环境、人口、经济发展之间的关系入手，分析探讨水环境承载力的内涵，并在此基础上，建立了研究区域水环境载力的大系统分解协调模型，将模型应用于关中地区，得到不同方案下关中地区水环境承载力及提高关中水环境承载力最优策略。     

长江经济带国家生态文明建设示范市县生态文明发展状况评估

研究长江经济带第一批国家生态文明建设示范市县的生态文明建设水平,可为下一步生态文明建设工作提供指导.选取生态环境、经济社会方面的6个关键指标,分析了各示范市县生态文明发展时空变化趋势.结果表明,各示范市县6个指标基本能实现稳定向好,到2019年指标值优于本省(市)平均指标值的示范市县数量分别占81.25％、87.50％...