A project-based system for including farmers in the EU ETS

Farmers in the EU do not trade greenhouse gases under the Kyoto agreement. This is an empirical puzzle because agriculture is a significant contributor of greenhouse gases (GHG) in the EU and may harvest private net gains from trade. Furthermore, the US has strongly advocated land-use practices as 'the missing link' in past climate negotiations. We argue that farmers have relatively low marginal reduction costs and that consequences in terms of the effect on permit price and technology are overall positive in the EU Emission Trading System (ETS). Thus, we propose a project-based system for including the farming practices in the EU ETS that reduces the uncertainty from measuring emission reduction in this sector. The system encourages GHG reduction either by introducing a new and less polluting practice or by reducing the polluting activity. When doing so, farmers will receive GHG permits corresponding to the amount of reduction which can be stored for later use or sold in the EU ETS.     

江西赣州站大气CO2和CH4浓度变化特征研究

通过分析2018年12月—2019年11月江西赣州站大气CO₂和CH₄浓度高精度在线观测资料,对其CO₂和CH₄浓度变化特征进行了研究,分析了区域大气输送的影响以及潜在排放源区分布特征.结果表明：研究期内赣州站CO₂和CH₄的平均浓度分别为433.1×10^-6和2142.5×10^-9.赣州站CO₂和CH₄浓度日变化均表现为日间低、早晚高,CO₂浓度日振幅在夏季最大,为29.7×10^-6,冬季最小,为6.9×10^-6.CH₄浓度日振幅在秋季最大,为145.1×10^-9,冬季最小,为41.4×10^-9.CO₂本底浓度季节变化表现为4—8月迅速下降,8—11月逐渐上升,最大值出现在1月,最小值出现在8月,季节振幅为26.2×10^-6.CH₄本底浓度季节变化表现为1—7月逐渐下降,7—9月逐渐上升,最大值出现在1月,最小值出现在7月,季节振幅为79.5×10^-9,基本可代表江西赣州地区混合均匀大气的CO₂和CH₄季节变化状况.与南昌站对比分析表明,赣州站各季节CO₂和CH₄本底浓度均低于南昌站.赣州地区CO₂和CH₄潜在源区主要分布在江西北部、湖北东部、安徽南部和珠江三角洲地区.     

施氮强度对不同土壤有机碳水平桉树林温室气体通量的影响

施氮或氮沉降对土壤温室气体通量影响已有比较深入的研究,但施氮对不同有机碳水平的土壤温室气体通量影响及其差异的研究较少.本研究以我国南方广泛种植的桉树人工林为对象,采用野外控制实验和室内分析,比较研究4种施氮处理(对照C:0 kg·hm-2;低氮L:84.2 kg·hm-2;中氮M:166.8 kg·hm-2;高氮H:333.7 kg·hm-2)对土壤有机碳水平存在显著性差异的2块桉树林样地土壤-大气界面温室气体(CO2、N2O和CH4)通量的影响.结果表明:1施氮对CO2和N2O排放通量有明显"激发效应",氮肥施用一个月后各个施氮处理土壤CO2和N2O排放通量出现最大值,随着时间推移至生长季后期CO2和N2O排放通量逐渐降低,差异逐渐缩小.施氮对CH4吸收通量的影响不显著(P>0.05).2施氮强度和土壤有机碳水平均显著促进了CO2和N2O排放(P<0.001),但对CH4吸收没有显著影响(P>0.05);高土壤有机碳水平样地CO2和N2O排放通量显著高于低水平土壤有机碳样地(P<0.01).3施氮和土壤有机碳水平对CO2和N2O排放通量的影响存在显著的交互作用(P<0.05).与低土壤有机碳水平样地比较,高土壤有机碳水平样地CO2和N2O排放通量对施氮更为敏感:低氮水平就能显著促进CO2和N2O的排放.上述结果表明:施氮对桉树林温室气体排放通量的影响既与施氮强度有关,也与土壤有机碳水平密切相关.估算不同施氮水平下的温室气体通量变化时,由土壤有机碳不同带来的温室气体通量差异不可忽视.     

城市生活垃圾集装箱转运过程中污染物产生状况研究

以上海市某生活垃圾中转站垃圾集装箱为研究对象,分析了1 a不同季节中转站集装箱内垃圾二次污染物的产生和变化规律.结果表明,集装箱内产生的主要气体指标中,H2S的变化范围为0.3~10.3 mg·m-3;CH4的变化范围为0.02%~2.97%;NH3的变化范围为0.7~4.5 mg·m-3,浓度峰值都出现在夏季.产生的渗滤液水质指标中,pH值在5.4~6.3之间变化,呈现酸性;SS在9 120~32 475 mg·L-1之间变化,波动较大;有机物COD的变化范围为41 633~84 060 mg·L-1,BOD5在18 116~34 130 mg·L-1之间变化,呈现出冬季高于夏季的特点;氨氮和总磷的变化范围分别为537~1 222 mg·L-1和17.98~296 mg·L-1之间,季节变化不明显.极端温度特别是夏季高温对箱体内气体污染物的产生影响明显,警示夏季要谨防在高温暴露和过长的停留时间,以防止易燃易爆气体和其他污染物的大量产生.     

活化温度对竹柳基活性炭性能及其制备过程中副产物组成的影响

以一种常见的环境修复材料竹柳为原料来制备竹柳基活性炭(WAC),考察了不同活化温度(400、450、500、550、600℃和650℃)对WAC性质及其除污染性能的影响,同时评估了制备过程中气态和液态副产物的生成规律与利用潜能.结果表明,随着活化温度的升高,WAC产率下降,热解油产率上升,而热解气产率相对稳定.六组WAC均具有较高的比表面积(BET),最高可达1526 m2·g-1,但BET值随活化温度的升高呈下降趋势;WAC的碘吸附值和亚甲基蓝吸附值最高可达1122.25 mg·g-1和415.50 mg·g-1,对重金属Pb2+和硝基苯的最大吸附量分别为9.20mg·g-1和4.21 mmol·g-1.WAC制备过程中热解气主要组分为H2、CH4、CO和CO2,随活化温度升高,H2和CH4含量上升,CO2含量下降,热解气的总燃烧热值升高.热解油的组分较为复杂,杂环类、烷烃类、烯烃类和有机酸类有机物含量较高,且随活化温度变化明显,在活化温度为650℃时,热解油的燃烧热最大.     

秸秆及配施工农业废弃物对茉莉种植园碳排放的影响

废弃物的农业资源化是当前研究的热点之一,但将其应用于环境效应评价还鲜见报道.通过实验测定,探讨了秸秆及秸秆分别配施石膏渣、生物炭、炉渣对福州茉莉园碳排放及其综合增温潜势的影响.结果表明:与对照相比,施加秸秆CH_4排放通量提高了20.05%;与秸秆处理相比,秸秆配施石膏渣和秸秆配施生物炭不同程度地提高了CH_4排放通量,而秸秆配施炉渣的CH_4排放通量则有所降低.与对照相比,施加秸秆CO_2排放通量提高了30.45%;与秸秆处理相比,秸秆配施石膏渣提高了CO_2排放通量,而秸秆配施生物炭和秸秆配施炉渣的CO_2排放通量均有所降低.CO_2对茉莉园碳排放和综合增温潜势贡献较大,碳排放和综合增温潜势均表现为秸秆配施石膏渣秸秆秸秆配施生物炭秸秆配施炉渣对照,秸秆处理的碳排放和增温潜势较对照分别提高了30.42%和30.18%,秸秆配施石膏渣较秸秆处理提高了碳排放和综合增温潜势,而秸秆配施生物炭和秸秆配施炉渣的碳排放和综合增温潜势均有所降低.从温室气体综合增温潜势来看,秸秆配施生物炭或炉渣可作为茉莉园固碳减排的有效配套措施.     

Response of gaseous carbon emissions to low-level salinity increase in tidal marsh ecosystem of the Min River estuary, southeastern China

Although estuarine tidal marshes are important contributors to the emission of greenhouse gases into the atmosphere, the relationship between carbon dioxide(CO_2), methane(CH_4)emission, and environmental factors, with respect to estuarine marshes, has not been clarified thoroughly. This study investigated the crucial factors controlling the emission of CO_2 and CH_4from a freshwater marsh and a brackish marsh located in a subtropical estuary in southeastern China, as well as their magnitude. The duration of the study period was November 2013 to October 2014. Relevant to both the field and incubation experiments, the CO_2 and CH_4emissions from the two marshes showed pronounced seasonal variations. The CO_2 and CH_4emissions from both marshes demonstrated significant positive correlations with the air/soil temperature(p 0.01), but negative correlations with the soil electrical conductivity and the pore water/tide water Cl-and SO_4~(2-)(p 0.01). The results indicate no significant difference in the CO_2 emissions between the freshwater and brackish marshes in the subtropical estuary, whereas there was a difference in the CH_4 emissions between the two sites(p 0.01). Although future sea-level rise and saltwater intrusion could reduce the CH_4 emissions from the estuarine freshwater marshes, these factors had little effect on the CO_2 emissions with respect to an increase in salinity of less than 5‰. The findings of this study could have important implications for estimating the global warming contributions of estuarine marshes along differing salinity gradients.     

污水处理行业温室气体核算模型开发及减排潜力分析

城镇污水处理行业是我国现代化进程中不可或缺的一部分,它承担着城镇污水处理和减排的重要作用,在运行过程中不可避免会产生大量的温室气体。本研究基于污水处理过程中的温室气体排放机理及排放因子法,构建了污水处理温室气体核算模型,并应用于国内典型的某厌氧—缺氧—好氧工艺的污水处理厂。研究结果表明,开发的模型能够有效识别出厌氧—缺氧—好氧工艺温室气体排放占比较高的环节,该环节为污水处理过程中电耗和污水处理过程中的甲烷排放,其在整个温室气体排放系统内占比高达93.09%。污水处理厂可以采取减小曝气量的措施使溶解氧达到2 ～ 3 mg/L,从而降低污水处理系统曝气电耗;另外,优化泵及鼓风机的运行,选用变频调速水泵等措施,可以降低污水提升环节能耗,达到温室气体间接减排的目的。污水处理厂还可以采取甲烷产能回收利用措施,将CH₄燃烧产生的能量作为污水处理系统内的能源供应,这样不仅可以有效减少污水处理厂的能耗,而且可以实现污水处理过程中温室气体排放减量化。     

Heterogeneous reaction of SO2 on CaCO3 particles: Different impacts of NO2 and acetic acid on the sulfite and sulfate formation

Despite the heterogeneous reaction of sulfur dioxide (SO₂) on mineral dust particles significantly affects the atmospheric environment, the effect of acidic gases on the formation of sulfite and sulfate from this reaction is not particularly clear. In this work, using the in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) technique, we employed a mineral dust particle model (CaCO₃) combined with NO₂ and acetic acid to investigate their effects on the heterogeneous reaction of SO₂ on CaCO₃ particles. It was found that water vapor can promote the formation of sulfite and simulated radiation can facilitate the oxidation of sulfite to sulfate. The addition of NO₂ or acetic acid to the reaction system altered the production of sulfate and sulfite accordingly. There was a synergistic effect between NO₂ and SO₂ that promoted the oxidation of sulfite to sulfate, and a competitive effect between acetic acid and SO₂ that inhibited the formation of sulfite. Moreover, light and water vapor can also affect the heterogeneous reaction of SO₂ with the coexistence of multiple gases. These findings improve our understanding of the effects of organic and inorganic gases and environmental factors on the formation of sulfite and sulfate in heterogeneous reactions.     

铝合金生产中含氟废气的二段式喷淋处理工程简介

基于中式实验研究,介绍含氟废气采用二段式喷淋处理工艺技术,废气中含氟量从180～200g/m3降至2mg/m3;含氟溶液采用CaCO3-CaF2共沉淀技术,溶液中氟离子浓度达到1mg/L以下,喷淋水循环使用。