Study on the regional atomized dust suppression technological system based on the measured law of dust concentration distribution in longwall fully mechanized mining faces

Environment, Development and Sustainability - In order to reveal the distribution and migration law of downwind and upwind coal cutting, total dust (TD) and respirable dust (RD) concentration...     

Effect of combined addition amount of nano zero-valent iron and biochar on methane production by anaerobic digestion of corn straw

Environment, Development and Sustainability - Anaerobic digestion (AD) is an attractive straw resource treatment technology as it can improve the utilization efficiency of straw resource. Raw straw...     

哈尔滨市秸秆焚烧大气污染负荷估算方法研究

本文针对近些年哈尔滨秋末冬初大气污染程度增加的溯源问题,基于静风污染气象及降雪对秸秆焚烧的影响等基本假设,采用箱式模型和优化拟合的方法对秸秆焚烧产生污染物的源强及其负荷进行了估算.通过对2015年和2017年典型时段数据的优化拟合得到降雪前重污染天气下PM₁₀排放源强分别为20.16、21.83 μg·m^-2·s^-1,CO的排放源强分别为149.32、138.65 mg·m^-2·s^-1;降雪后重污染天气下PM₁₀排放源强分别为15.98、7.09 μg·m^-2·s^-1,CO的排放源强分别为122.91、89.21 mg·m^-2·s^-1.由降雪前后各污染物的源强差得到2015年和2017年秸秆焚烧产生的PM₁₀的排放源强分别为4.18、14.74 μg·m^-2·s^-1,负荷分别为20.73%、67.52%;CO的排放源强分别为26.41、49.44 mg·m^-2·s^-1,负荷分别为17.69%、35.66%.本文为相关清单的研究提供了一种客观的校核方法,具有重要的社会、环境及现实意义.     

面向国土空间规划的“双评价”：挑战与应对

面向国土空间规划的科学性、可操作性、层级性等内涵,探讨了资源环境承载能力评价和国土空间开发适宜性评价（“双评价”）与国土空间规划之间的基本逻辑问题、应用挑战与应对方法。通过系统梳理“双评价”的理论发展和相关政策响应,剖析了“双评价”在应用探索、内涵扩充、系统支撑三个阶段的研究重点和服务目标,阐明了承载力评价与适宜性评价之间关联逻辑的演进历程。总结了当前“双评价”在应用上的几个关键挑战：一是“双评价”应用于“三区三线”划定的逻辑尚未明确;二是当前承载能力评价与未来规划决策之间存在逻辑悖论;三是“双评价”在不同层级国土空间规划中传导失灵;四是两个评价之间的关联逻辑仍存在争议。为此,提出了应对“双评价”挑战的四点建议：深化理论认知、拓展评价维度、建立传导机制、厘清内在关系,以提升“双评价”对国土空间规划决策的支撑能力。     

地下水波动带中细菌群落结构与水质响应关系

为揭示地下水波动带中细菌群落结构特征及其与地下水环境相互作用关系,选取哈尔滨市第一水源地作为研究区,采集地下水样品以及波动带不同深度（0~5m非饱和带和6~50m饱和带）含水介质样品,分别用于水化学分析和16S rRNA细菌高通量测序,依托冗余分析定量表述地下水质参数与细菌群落相关性.水化学分析结果显示,研究区地下水主要污染物为Fe、Mn、NH₄⁺和有机质,Fe、Mn超标与研究区特定地质背景有关,NH₄⁺和有机质主要来源于人类活动.微生物分析结果显示,非饱和带和饱和带的细菌群落结构差异性显著,非饱和带细菌群落丰度和多样性显著高于饱和带,Proteobacteria、Bacteroidetes、Actinobacteria、Firmicutes和Acidobacteria为研究区优势门,在非饱和带和饱和带的累积相对丰度分别为82.89%和98.64%.冗余分析（RDA）结果显示,门水平上非饱和带中与水质演化强相关的细菌类群是Bacteroidetes、Proteobacteria、Actinobacteria、Verrucomicrobia,贡献率分别为15%、14.8%、8.9%和5.2%;饱和带中对地下水质演化起主要作用的类群为Bacteroidetes、Acidobacteria、Actinobacteria和Firmicutes,贡献率分别为38.4%、19.0%、10.8%和9.1%.属水平上非饱和带中的Pseudomonas和饱和带中的Flavobacterium对Fe、Mn、NH₄⁺生物转化起主导作用.本研究为揭示地下水波动带中生物地球化学作用对地下水环境的影响提供了科学依据,对地下水污染修复具有重要的意义.     

MnCeOx/沸石催化剂对工业典型VOCs的催化性能

以沸石为载体制备了锰铈复合氧化物催化剂（记为:MnCeO_x/沸石催化剂）,探究了催化剂对工业典型VOCs的二元催化性能,并对催化剂进行BET、XRD及SEM表征。结果表明:Ce的加入,促进了Mn的分散,提高了MnCeO_x/沸石催化剂的活性;当n（Mn）∶n（Ce）为1∶1,负载率为20%,焙烧温度为500℃时,催化剂的活性最高,其对甲苯的起燃温度（T₅₀）和完全燃烧温度（T₉₀）分别为155,255℃;单组分实验中,催化剂对3种有机物均表现出较高活性,转化率达到90%时的反应温度均在275℃以下,其活性顺序为乙酸乙酯>甲苯>丙酮,主要受反应活化能大小及分子极性的影响;二元催化实验中,由于竞争吸附的影响,3种物质的T₅₀和T₉₀较单组分均分别提高了8~13,14~38℃。     

Tuning the fill percentage in the hydrothermal synthesis process to increase catalyst performance for ozone decomposition

The performance of Ce-OMS-2 catalysts was improved by tuning the fill percentage in the hydrothermal synthesis process to increase the oxygen vacancy density. The Ce-OMS-2 samples were prepared with different fill percentages by means of a hydrothermal approach (i.e. 80%, 70%, 50% and 30%). Ce-OMS-2 with 80% fill percentage (Ce-OMS-2-80%) showed ozone conversion of 97%, and a lifetime experiment carried out for more than 20?days showed that the activity of the catalyst still remained satisfactorily high (91%). For Ce-OMS-2-80%, Mn ions in the framework as well as K ions in the tunnel sites were replaced by Ce⁴⁺, while for the others only Mn ions were replaced. O₂-TPD and H₂-TPR measurements proved that the Ce-OMS-2-80% catalyst possessed the greatest number of mobile surface oxygen species. XPS and XAFS showed that increasing the fill percentage can reduce the AOS of Mn and augment the amount of oxygen vacancies. The active sites, which accelerate the elimination of O₃, can be enriched by increasing the oxygen vacancies. These findings indicate that increasing ozone removal can be achieved by tuning the fill percentage in the hydrothermal synthesis process.     

Role of glycine on sulfuric acid-ammonia clusters formation: Transporter or participator

Glycine(Gly) is ubiquitous in the atmosphere and plays a vital role in new particle formation(NPF).However,the potential mechanism of its on sulfuric acid(SA)-ammonia(A)clusters formation under various atmospheric conditions is still ambiguous.Herein,a(Gly)_x·(SA)_y·(A)_z(z≤x+y≤3) multicomponent system was investigated by using density functional theory(DFT) combined with Atmospheric Cluster Dynamics Code(ACDC) at different temperatures and precursor concentrations.The results show that Gly,with one carboxyl(-COOH) and one amine(-NH_2) group,can interact strongly with SA and A in two directions through hydrogen bonds or proton transfer.Within the relevant range of atmospheric concentrations,Gly can enhance the formation rate of SA-A-based clusters,especially at low temperature,low [SA],and median [A].The enhancement(R) of Gly on NPF can be up to 340 at T=218.15 K,[SA]=10~4,[A]=10~9,and [Gly]=10~7 molecules/cm~3.In addition,the main growth paths of clusters show that Gly molecules participate into cluster formation in the initial stage and eventually leave the cluster by evaporation in subsequent cluster growth at low [Gly],it acts as an important "transporter" to connect the smaller and larger cluster.With the increase of [Gly],it acts as a "participator" directly participating in NPF.