The dynamics of landfill diversion: Economic drivers, policy factors and spatial issues: Evidence from Italy using provincial panel data

Waste disposal is an issue that is becoming increasingly important in policy terms in the European Union, and in Italy, a country showing strong geographical heterogeneity in waste management. This paper analyses the process of decoupling/delinking between economic growth and landfilling trends in a framework where economic, policy, geographical elements and spatial issues are all considered as drivers behind the phenomenon. We exploit an original and very rich provincial panel dataset over 1999–2005 for the 103 Italian provinces. Evidence shows that the observed ‘absolute’ decoupling between economic growth and landfilling is driven by a mix of structural factors. Among the main factors, population density, more than the provincial income level, emerges as a crucial driver: local opportunity costs and landfill externalities matter in shaping waste policies and local commitment to a transition away from landfilling of waste (landfill diversion). However, not only structural factors are relevant. If on the one hand landfill taxes are not a significant driver of the phenomenon, waste management tools, such as separated collection for recycling, and the tariff system connected to waste services, bring about significant effect on the amount of landfilled waste. Moreover, regarding the analysis of spatial interrelations across provinces, we note that the presence of incinerators in nearby provinces increases landfill diversion, due probably to free riding behaviour or intra-provinces ‘agreements’ on waste management; this is not true for nearby landfill sites, that cause for a given province a strong lock in effect. Future research could strengthen the analysis of policy effectiveness at regional level, focusing on policy endogeneity, and the full investigation of spatial correlations in waste disposal performances.     

生物标志物在水环境研究中的应用

生物标志物是指示污染物危害效应的生物信号．可分为两类,一类指示生物体对有害物质的暴露;另一类指示污染物的毒性效应．与其它手段相比,生物标志物具有专一性、预警性和广泛适用性．本文介绍了指示水环境污染的主要几类生物标志物．生物转化酶和金属硫蛋白能有效地表征水体中的有机物和重金属对生物的影响．DNA加合物将有机污染与遗传物质变异相关联,因此成为生态毒理学研究的新热点．文中还讨论了生物标志物的缺陷和不足,并展望了该领域的应用前景．     

Meta‐Analysis of the Effects of Forest Fragmentation on Interspecific Interactions

Forest fragmentation dramatically alters species persistence and distribution and affects many ecological interactions among species. Recent studies suggest that mutualisms, such as pollination and seed dispersal, are more sensitive to the negative effects of forest fragmentation than antagonisms, such as predation or herbivory. We applied meta‐analytical techniques to evaluate this hypothesis and quantified the relative contributions of different components of the fragmentation process (decreases in fragment size, edge effects, increased isolation, and habitat degradation) to the overall effect. The effects of fragmentation on mutualisms were primarily driven by habitat degradation, edge effects, and fragment isolation, and, as predicted, they were consistently more negative on mutualisms than on antagonisms. For the most studied interaction type, seed dispersal, only certain components of fragmentation had significant (edge effects) or marginally significant (fragment size) effects. Seed size modulated the effect of fragmentation: species with large seeds showed stronger negative impacts of fragmentation via reduced dispersal rates. Our results reveal that different components of the habitat fragmentation process have varying impacts on key mutualisms. We also conclude that antagonistic interactions have been understudied in fragmented landscapes, most of the research has concentrated on particular types of mutualistic interactions such as seed dispersal, and that available studies of interspecific interactions have a strong geographical bias (arising mostly from studies carried out in Brazil, Chile, and the United States). Meta‐Análisis de los Efectos de la Fragmentación del Bosque sobre las Interacciones Interespecíficas     

稻田综合种养土地利用的生态—经济效果——以湖北省稻虾共作为例

关注以稻虾共作为代表的稻田综合种养土地利用新型模式,基于在湖北省潜江市和荆州市的实地调研数据,运用非期望产出的SBM模型和投入导向DEA方法,测算和比较了稻虾共作户和水稻单作户土地利用的生态—经济效果。研究发现：与水稻单作相比,稻虾共作能够改善土地利用的生态—经济效果;但调研区一半以上的共作农户仍然延续着传统粗放的生产模式,生产中存在严重的过量投入,阻碍了其土地利用生态—经济效果的进一步优化。此外,若忽略环境污染,只考虑经济效果,将导致稻虾共作的土地利用效率被高估45.28%。目前,稻虾共作提高土地利用效率的功能未能充分发挥,亟需把环境影响纳入土地利用效率评估中,贯彻“双水双绿”的发展理念,引导农户合理安排各项生产投入,切实优化稻虾共作的生态—经济效果,促进土地可持续利用。     

Hydrogen generation from polyvinyl alcohol-contaminated wastewater by a process of supercritical water gasification

Gasification of polyvinyl alcohol(PVA)-contaminated wastewater in supercritical water(SCW)was investigated in a continuous flow reactor at 723-873 K,20-36 MPa and residence time of 20-60 s.The gas and liquid products were analyzed by GC/TCD,and TOC analyzer.The main gas products were H_2,CH_4,CO and CO_2.Pressure change had no significant influence on gasification efficiency. Higher temperature and longer residence time enhanced gasification efficiency,and lower temperature favored the production of H_2. The effects of KOH catalyst on gas product composition were studied,and gasification efficiency were analyzed.The TOC removal efficiency(R_(TOC)),carbon gasification ratio(R_(CG))and hydrogen gasification ratio(R_(HG))were up to 96.00%,95.92% and 126.40% at 873 K and 60 s,respectively,which suggests PVA can be completely gasified in SCW.The results indicate supercritical water gasification for hydrogen generation is a promising process for the treatment of PVA wastewater.     

芒荻类植物资源的开发和利用

研究发现,特产于我国东部的南荻TriarrhenalutarioriparaL.Liusp.nov.新种,植株高大,每年秆生长高度达5～7m,年产22.5～30t/hm²干荻秆;秆的纤维细胞含量50%左右(43%～65%),纤维细胞长度平均为3mm,最长可达6.8mm,是制造上等纸张的优质草类原料。芒荻类属于高光效碳四(C⁴)植物,是有价值的环保植物,在生长过程中,它比一般植物能更多地吸收CO²和放出O²,对平衡大气中的CO²/O²十分有利,并能降低温室效应。研究证明,南荻对环境适应演化的独特机制,能将大面积河湖荒滩湿地改变成为创造经济生态环保效益的生产基地。     

中国自由贸易试验区是否抑制了环境污染——来自中国281个城市的实证研究

加快建设贸易强国,提高对外开放水平,是推进高水平对外开放进而实现高质量发展的重大课题。然而,贸易引致而来的环境问题不容忽视,如何有效防治环境污染,推动绿色发展,成为高质量发展中亟须解决的问题之一。本文以自由贸易试验区作为“准自然实验”,利用2005—2019年中国城市的面板数据,通过双重差分法探究贸易与环境的关系。研究发现：自贸区能够显著抑制片区所在城市的环境污染,该结论在考虑内生性问题以及多种稳健性检验后依然成立;自贸区通过优化地区产业结构、提高地区绿色创新能力以及促进地区经济集聚三个作用渠道来抑制地区环境污染;自贸区对地区环境污染的抑制作用存在地理、行政异质性,中西部城市和副省级以上城市的抑制环境污染效应更显著;自贸区在抑制环境污染方面具有空间溢出效应,能够对邻近地区的环境污染起到显著的遏制作用;在抑制环境污染方面,自贸区与“一带一路”倡议之间存在联动作用。本文为丰富自贸区的政策内涵、实现贸易与环境双赢发展提供了新思路。     

海南水基钻屑中典型元素分布及其铺垫井场后对地下水的影响

铺垫井场是水基钻屑再利用的重要路径。然而,不同区域水基钻屑中元素浓度存在差异,其再利用过程中环境影响仍未全面了解。调查海南5个典型油气田钻井平台的水基钻屑,分析典型元素的分布和浸出特征,评估铺垫井场后对地下水的环境影响。结果表明,海南水基钻屑中Ni、As、Se、Sb、Pb、Hg、Tl、Mo、Ba浓度均未超过GB 36600—2018《土壤环境质量 建设用地土壤污染风险管控标准（试行）》中规定的第二类用地的风险筛选值,除Tl外,其他元素浓度均与采样深度显著相关。浸出液中Pb、Tl、As浓度相对于GB/T 14848—2017《地下水质量标准》规定的Ⅲ类限值分别有36.5%、16.5%、16.5%的超标率,其中As浸出率最高,为35.7%。基于Texas模型的估算以及铺垫井场下方地下水的现场测定,所有检测项目浓度均未超过GB/T 14848—2017规定的Ⅲ类限值,表明水基钻屑铺垫井场是安全的。