Knowledge, values, uses and management of the Araucaria araucana forest by the indigenous Mapuche Pewenche people: A basis for collaborative natural resource management in southern Chile

One of the most important endemic tree species of Chile and at the same time one of the most endangered ones is Araucaria araucana (Mol.) C. Koch, the monkey‐puzzle tree. It grows in the Andes Mountains, homeland of the indigenous Mapuche Pewenche people who depend on this tree. This paper is based on field research that investigated the ecological knowledge, uses and management of the Araucaria araucana forest by indigenous Mapuche Pewenche people based on the socio‐cultural, spiritual and ecological relationships they have with the Araucaria forest, to find out how indigenous people and their knowledge could contribute to sustainable Araucaria forest management. A Mapuche Pewenche community located in the IX region of Chile contributed to this study. Based on the analyses this paper illustrates the nature of indigenous ecological knowledge of Araucaria araucana on the one hand, and its utility in native forest management on the other. The research shows that the Mapuche Pewenche hold ecological knowledge and conduct practices to manage their Araucaria forest in a balanced way. They conserve and use forest biodiversity at one and the same time. This paper provides recommendations for sustainable Araucaria forest management and conservation strategies ex‐situ and in‐situ incorporating indigenous knowledge and scientific knowledge and for promoting a collaborative natural resources management.     

Discounting in the presence of scarce ecosystem services

The discount rate for cost-benefit analysis has to take account of future scarcity of ecosystem services in consumption and production. Previous literature focuses on the first aspect and shows the importance of the relative price effect, for given growth rates of consumption and ecosystem services. This paper focuses on intermediate ecosystem services in production and shows that for limited substitutability and a low growth rate of these ecosystem services, the growth rate of consumption, and thus the discount rate, declines towards a low value. Using a Ramsey growth model, the paper distinguishes three cases. If ecosystem services can be easily substituted, the discount rate converges to the usual value in the long term. Secondly, if ecosystem services can be easily substituted in production but not in consumption, the relative price effect is important. Finally, and most interestingly, if ecosystem services cannot be easily substituted in production, the discount rate declines towards a low value and the relative price effect is less important. Another part of the previous literature has shown that a declining discount rate is the result of introducing several forms of uncertainty, but this paper reaches that conclusion from an endogenous effect on the growth rate of the economy.     

A hybrid decision-making approach based on FCM and MOORA for occupational health and safety risk analysis

IntroductionWith the development of industries and increased diversity of their associated hazards, the importance of identifying these hazards and controlling the Occupational Health and Safety (OHS) risks has also dramatically augmented. Currently, there is a serious need for a risk management system to identify and prioritize risks with the aim of providing corrective/preventive measures to minimize the negative consequences of OHS risks. In fact, this system can help the protection of employees’ health and reduction of organizational costs. Method: The present study proposes a hybrid decision-making approach based on the Failure Mode and Effect Analysis (FMEA), Fuzzy Cognitive Map (FCM), and Multi-Objective Optimization on the basis of Ratio Analysis (MOORA) for assessing and prioritizing OHS risks. After identifying the risks and determining the values of the risk assessment criteria via the FMEA technique, the attempt is made to determine the weights of criteria based on their causal relationships through FCM and the hybrid learning algorithm. Then, the risk prioritization is carried out using the MOORA method based on the decision matrix (the output of the FMEA) and the weights of the criteria (the output of the FCM). Results: The results from the implementation of the proposed approach in a manufacturing company reveal that the score at issue can overcome some of the drawbacks of the traditional Risk Priority Number (RPN) in the conventional FMEA, including lack of assignment the different relative importance to the assessment criteria, inability to take into account other important management criteria, lack of consideration of causal relationships among criteria, and high dependence of the prioritization on the experts’ opinions, which finally provides a full and distinct risk prioritization.     

Nitrogen evolution during the co-combustion of hydrothermally treated municipal solid waste and coal in a bubbling fluidized bed

Nitrogen evolution was studied during the co-combustion of hydrothermally treated municipal solid wastes (HT MSW) and coal in a bubbling fluidized bed (BFB). HT MSW blending ratios as 10%, 20% and 30% (wt.%) were selected and tested at 700, 800, 900 °C. Emissions of NO and N₂O from blends were measured and compared with the results of mono-combustion trials. Moreover, concentrations of precursors like NH₃ and HCN were also quantified. The results are summarized as follows: NO emissions were predominant in all the cases, which rose with increasing temperature. The blending of HT MSW contributed to the NO reduction. N₂O emissions decreased with temperature rising and the blending of HT MSW also presented positive effects. At 30% HT MSW addition, both NO and N₂O emissions showed the lowest values (391.85 ppm and 55.33 ppm, respectively at 900 °C). For the precursors, more HCN was detected than NH₃ and both played important roles on the gas side nitrogen evolution.     

不同运行模式下改良型CAST工艺处理生活污水的除磷性能

实验采用改良型CAST工艺,以生活污水为研究对象,考察了C/P、回流比及温度等不同运行模式对系统除磷性能的影响.结果表明,常温条件下进水C/P由50升至100,系统除磷率均值从15%迅速升至95.6%,除磷性能显著提高;继而降低C/P至75,除磷性能因进水碳源不足再度下降,除磷率均值为51.4%,且长期投加易降解碳源引发系统污泥膨胀并导致污泥大量流失.C/P较低情况下,回流比由25%降低至12.5%,除磷性能提高2.3倍,继续降低回流比至0,除磷性能反而下降;温度实验研究则表明,低温系统(14℃±1℃),除磷率稳定维持在90%以上,而高温短程硝化系统(27℃±1℃)除磷率仅为14.1%,可见低温更有利于系统磷的去除.吸磷小试发现,常温系统污泥以O_2、NO_3~-和NO_2~-为电子受体均能进行吸磷,而低温系统污泥能以O_2、NO_3~-为电子受体进行吸磷,高温系统污泥则仅能以O_2为电子受体进行少量吸磷.此外,实验还发现,系统短期闲置导致的污泥"饥饿"有利于系统除磷率的提高.     

生活垃圾焚烧飞灰固化体力学及重金属浸出特性

以苏州七子山生活垃圾焚烧厂产生的飞灰为研究对象,采用水泥作为固化剂,研究水泥飞灰固化体的应力应变特征及重金属浸出特性,并探讨了水泥飞灰配合比、养护时间等关键性因素对这些特性的影响。实验结果表明:较养护3 d的样品,其余养护时间的样品强度平均增长了约96.2%,而其破坏应变平均减小了56%。随着水泥含量和养护时间的增加,飞灰固化体的强度上升,而其破坏应变减小,该趋势主要归因于钙矾石(AFt)的形成促进了飞灰固化体强度的发展。较飞灰原样,飞灰固化体的重金属浸出浓度随着水泥含量、养护时间的增加而降低了38%~99%,重金属的迁移被限制,主要归因于水化硅酸钙(C—S—H)和钙矾石(AFt)的形成,以及飞灰和水泥水化反应创造的强碱性环境。     

厌氧发酵处理庆大霉素菌渣的可行性及条件优化

采用厌氧发酵处理庆大霉素菌渣,考察了含固率、接种比、接种污泥、发酵底物等因素对庆大霉素菌渣厌氧发酵的影响,并用累积净甲烷产量衡量庆大霉素菌渣进行厌氧发酵的可行性及发酵程度。试验结果证实了庆大霉素菌渣进行厌氧发酵的可行性,其中含固率和接种比对发酵的影响较大,最佳条件为含固率5%,接种比1/3;对比试验所用3种接种污泥,发现接种某造纸厂污水处理IC反应器的厌氧颗粒污泥效果最优,在最优含固率和接种比的条件下,累积净产甲烷量为28.21 m3/t;此外,试验还证实,采用不同菌渣的联合发酵表现出了明显的协同作用,在最优条件下,庆大霉素菌渣与林可霉素菌渣按1∶2的比例联合发酵的产甲烷量可达到37.5 m3/t。     

不同污水处理工艺N_2O减排方法研究进展

污水处理过程中产生强温室气体N_2O的问题已经受到广泛关注,如何在保证处理效率的同时实现N_2O有效减排成为水处理领域面临的重要问题。综述了传统生物脱氮除磷工艺和同步硝化反硝化、反硝化除磷、厌氧氨氧化等新型污水处理工艺运行过程中N_2O的产生机理、减排方法和减排量,为相关领域的研究人员提供参考。     

运用批实验研究溶解氧对米酒去除硝酸盐的影响

为了判别不同溶解氧条件下脱氮效果和碳的需求量,在水温为25~30℃条件下,设置了缺氧、微氧和有氧3种输入条件,以及C/N分别为2.0、1.5两种碳源投放量开展实验。研究表明:溶解氧的存在对反硝化作用的启动有延迟作用,但影响较小。溶解氧对于反硝化过程并没有产生明显的抑制作用,但在溶解氧较低的情况下,反硝化速率更为理想。缺氧条件下,C/N的适宜值应低于1.5;微氧条件下的C/N适宜值在1.5~2.0;而在有氧条件下C/N=2.0时可高效去除硝酸盐。该研究可为农村地区家庭自行去除饮用水中硝酸盐的实际应用提供参考。     

湖北省PM2.5与PM10比值分析及PM2.5时空分布特征研究

基于2012年-2014年湖北省大气污染物监测数据,通过数据反演方法,得到湖北省17个城市的PM2.5年均浓度.利用ArcGIS绘制出各城市不同年份的颗粒物浓度空间分布图,并对其进行分析.结果表明,2012年-2014年间,湖北省17个城市PM2.5与PM10年均浓度比值为0.66,PM2.5年均浓度超出国家二级标准,整体呈现上升趋势.城市方面,在多数城市PM2.5与PM10浓度上升的同时,仅武汉、黄冈和天门3个城市颗粒物浓度2014年较2013年有所下降,且武汉市PM2.5浓度下降率达12.8%,表明武汉市近两年来采取的政策措施具有较好的可行性和有效性.