A survey of municipal solid waste landfills in Beijing during 2009–2011

The investigation of municipal solid waste (MSW) treatment in China is rare due to its sensitivity and difficulty in terms of access. We chose Beijing, the capital of China, as an example to identify the characteristics of MSW landfill treatments using a 2-month investigation with 20 participants. MSW landfill treatments account for nearly 70% of the annual MSW disposal in Beijing; the landfill processes are equipped with many kinds of technologies and consume a large amount of energy and produce a variety of contaminants. The cover method (the most obvious difference in landfill tamping) mainly includes high-density polyethylene (HDPE) geomembranes with loess and soil alone (i.e., loess or sandy soil). We investigated the actual conditions of landfills and collected data on leachate and landfill gas (LFG) emissions and energy consumption during 2009–2011. The results indicated that the cover method employed by landfills was related to treatment quantity, operation, and especially landfill location. Early large-scale landfills located in plains were covered with HDPE geomembranes, and newly built landfills covered with soil tended to be equipped with HDPE covers. Using HDPE cover also contributed greatly to LFG production due to its impermeability but had no remarkable effect on leachate yield reduction due to the dry climate in Beijing. The potential was reinforced by the potentials of decrement and reuse. The disposal method of LFG can be optimized, and the power generated by the LFG process can meet the landfill demand. The gray water recycled from the leachate could be used in the landfill process.

     

Different sources of rural household energy consumption and influencing factors in Dazu,China

Rural household energy consumption is an important component of national energy consumption. This paper explores the rural household energy consumption status and influencing factors on different sources of rural household energy consumption in western China. Using data from a survey of 240 households conducted in 2017, this study finds that rural households’ energy consumption structure in the study area is a combination of traditional biomass energy and commercial energy sources. Fuelwood is the most commonly used fuel in the study area, while modern energy sources only occupy a low proportion. Rural household energy consumption is influenced by various factors. Individual perceptions of climate change, social trust and networks, and households’ socio-economic and demographic factors (gender, age, education, income per capita, household size, household location, and number of household appliances) are identified as having significant effects on rural households’ consumption of biomass and commercial energies. The research results provide implications for policy makers to formulate related rural energy policies to improve the rural energy consumption structure and future energy policy design in China and other developing countries.

     

Pyrolysis temperature influences ameliorating effects of biochars on acidic soil

The biochars were prepared from straws of canola, corn, soybean, and peanut at different temperatures of 300, 500, and 700 °C by means of oxygen-limited pyrolysis. Amelioration effects of these biochars on an acidic Ultisol were investigated with incubation experiments, and application rate of biochars was 10 g/kg. The incorporation of these biochars induced the increase in soil pH, soil exchangeable base cations, base saturation, and cation exchange capacity and the decrease in soil exchangeable acidity and exchangeable Al. The ameliorating effects of biochars on acidic soil increased with increase in their pyrolysis temperature. The contribution of oxygen-containing functional groups on the biochars to their ameliorating effects on the acidic soil decreased with the rise in pyrolysis temperature, while the contribution from carbonates in the biochars changed oppositely. The incorporation of the biochars led to the decrease in soil reactive Al extracted by 0.5 mol/L CuCl₂, and the content of reactive Al was decreased with the increase in pyrolysis temperature of incorporated biochars. The biochars generated at 300 °C increased soil organically complexed Al due to ample quantity of oxygen-containing functional groups such as carboxylic and phenolic groups on the biochars, while the biochars generated at 500 and 700 °C accelerated the transformation of soil exchangeable Al to hydroxyl-Al polymers due to hydrolysis of Al at higher pH. Therefore, the crop straw-derived biochars can be used as amendments for acidic soils and the biochars generated at relatively high temperature have great ameliorating effects on the soils.     

A comparative analysis of endophytic bacterial communities associated with hyperaccumulators growing in mine soils

Interactions between endophytic bacterial communities and hyperaccumulators in heavy metal-polluted sites are not fully understood. In this study, the diversity of stem-associated endophytic bacterial communities of two hyperaccumulators (Solanum nigrum L. and Phytolacca acinosa Roxb.) growing in mine soils was investigated using molecular-based methods. The denaturing gradient gel electrophoresis (DGGE) analysis showed that the endophytic bacterial community structures were affected by both the level of heavy metal pollution and the plant species. Heavy metal in contaminated soil determined, to a large extent, the composition of the different endophytic bacterial communities in S. nigrum growing across soil series (five sampling spots, and the concentration of Cd is from 0.2 to 35.5 mg/kg). Detailed analysis of endophytic bacterial populations by cloning of 16S rRNA genes amplified from the stems of the two plants at the same site revealed a different composition. A total of 51 taxa at the genus level that included α-, β-, and γ-Proteobacteria (68.8% of the two libraries clones), Bacteroidetes (9.0% of the two libraries clones), Firmicutes (2.0% of the two libraries clones), Actinobacteria (16.4% of the two libraries clones), and unclassified bacteria (3.8% of the two libraries clones) were found in the two clone libraries. The most abundant genus in S. nigrum was Sphingomonas (23.35%), while Pseudomonas prevailed in P. acinosa (21.40%). These results suggest that both heavy metal pollution and plant species contribute to the shaping of the dynamic endophytic bacterial communities associated with stems of hyperaccumulators.     

“控源-截污-资源化”模式处理面源污染

针对农村面源污染的时空范围广,不确定性大,成分、过程复杂,难以控制的特点,同时考虑废物资源化的问题,提出了"控污-截污-资源化(再利用)"CIR模式,包括三方面:通过改变不良用水习惯及耕作方式等从源头上控制污染排放;利用植物缓冲带、自然塘、沟渠湿地和表面流湿地等达到截污的目的;将畜禽养殖废水及生活黑水集中处理,产生沼气,变废为宝,于湿地内种植经济类水生植物,兼性塘内水产养殖,最终实现废物资源化(再利用)。经过将近一年半的运行测试,测试结果表明,整个模式不仅除污效率高,而且可产生良好的经济效益。     

基于无机氮磷利用特征的小球藻优化培养技术

氮磷对小球藻的生长产生重要影响,基于氮磷优化培养条件的探讨具有理论和实际意义。在静置培养、通气培养和通气加碳源（葡萄糖）培养等条件下对小球藻的生长影响和氮磷消耗进行了试验,采用分批取样补料方式对培养过程进行了优化研究。结果表明,在未调节培养液pH值条件下,藻液的pH值在7~9变化,随培养时间呈略微下降的趋势。各培养条件下,小球藻对硝酸盐的吸收速率均表现出先快后慢的特征,对磷的吸收利用表现为总磷先快速被吸收利用,然后稳定在一定范围内波动。小球藻的生长在静置培养条件下主要受培养液中硝酸盐氮含量和培养液pH值的影响,通气培养条件下主要受培养液中硝酸盐氮含量的影响,通气外加碳源培养条件下主要受培养液中可溶解性总磷含量和硝酸盐氮含量双重影响。在通气外加碳源分批取样补料的藻类优化培养中,生长中期取样补料小球藻生长速率受影响较小,单位时间生物量最高,达3 565 mg/（L·d     

火山石生物滤床对微囊藻毒素的去除

微囊藻水华爆发导致大量微囊藻毒素释放至地表水环境中,严重威胁着饮用水供水安全.通过不同条件火山石自然曝气生物滤床(活性挂膜、灭活挂膜、未挂膜和无填料滤床)对不同形态、构型(MC-LR、MC-RR)的微囊藻毒素的去除实验,探讨其去除效率、途径和机理.结果表明,火山石自然曝气生物滤床对微囊藻毒素的去除是微生物降解和基质吸附共同作用的结果.胞外毒素和胞内毒素的总去除率分别为58％和91％.其中,胞外毒素主要通过微生物降解作用途径去除,占胞外毒素总去除率的(41±4.2)％,胞内毒素则主要通过基质吸附途径去除,占胞内毒素总去除率的(64±5.1)％.生物膜吸附、光降解等其他途径无明显作用.另外,不同构型的微囊藻毒素在火山石自然曝气生物滤床中均能有效去除,MC-LR和MC-RR的去除率分别为68％和54％.     

Interaction of As and Sb in the hyperaccumulator <Emphasis Type="Italic">Pteris vittata</Emphasis> L.: changes in As and Sb speciation by XANES

Arsenic (As) and antimony (Sb) are chemical analogs that display similar characteristics in the environment. The As hyperaccumulator Pteris vittata L. is a potential As–Sb co-accumulating species. However, when this plant is exposed to different As and Sb speciation, the associated accumulating mechanisms and subsequent assimilation processes of As and Sb remain unclear. A 2-week hydroponic experiment was conducted by exposing P. vittata to single AsIII, AsV, SbIII, and SbV or the co-existence of AsIII and SbIII and AsV and SbV. P. vittata could co-accumulate As and Sb in the pinna (>1000 mg kg^?1) with high translocation (>1) of As and Sb from the root to the pinna. P. vittata displayed apparent preference to the trivalent speciation of As and Sb than to the pentavalent speciation. Under the single exposure of AsIII or SbIII, the pinna concentration of As and Sb was 84 and 765 % higher than that under the single exposure of AsV or SbV, respectively. Despite the provided As speciation, the main speciation of As in the root was AsV, whereas the main speciation of As in the pinna was AsIII. The Sb in the roots comprised SbV and SbIII when exposed to SbV but was exclusively SbIII when exposed to SbIII. The Sb in the pinna was a mixture of SbV and SbIII regardless of the provided Sb speciation. Compared with the single exposure of As, the co-existence of As and Sb increased the As concentration in the pinna of P. vittata by 50–66 %, accompanied by a significant increase in the AsIII percentage in the root. Compared with the single exposure of Sb, the co-existence of Sb and As also increased the Sb concentration in the pinna by 51–100 %, but no significant change in Sb speciation was found in P. vittata.     

基于数据非依赖型采集质谱技术的血液脂质分子高通量分析

脂质是生物体的重要代谢分子,参与重要的细胞生物功能,已有报道表明环境中污染物会干扰生物体正常循环及代谢机制,导致脂肪代谢紊乱。基于数据非依赖型(DIA)采集质谱技术,通过优化UPLC-QTOF MS(超高效液相色谱飞行时间质谱联用)液相分离方法,开发了少量人体血液样品中脂质代谢分子的高通量分析方法,并将其应用于57个普通人群的血液样品分析,在10μL人体血液样品中检出2 598个信号,经脂代组学质谱库匹配解析鉴定出八大类1 780个脂质分子,其中分子数目占比最大的脂质为甘油磷脂类(37%),其次依次为脂肪酸类(23%)、固醇脂类(13%)、甘油脂类(10%)、鞘脂类(9.0%)、孕烯醇酮脂类(4.8%)。上述研究建立的脂质分子高通量分析方法为以脂质代谢为毒性终点的污染物毒性筛查和毒理机制研究提供方法学基础。     

Dynamic water quality evaluation based on fuzzy matter–element model and functional data analysis,a case study in Poyang Lake

Environmental Science and Pollution Research - Comprehensively evaluating water quality with a single method alone is challenging because water quality evaluation involves complex, uncertain, and...