区域环境噪声标准适用区域划分的定量化

根据国家环保局关于区域环境噪声环境划分的规定，提出了区域环境噪声标准定量化划分的模型，该模型综合了自然因素和噪声污染因素，模型在南通市区域环境噪声标准划分中得到了验证。     

基于MODIS的内蒙古气溶胶时空分布特征分析

通过对2002—2018年采用融合算法反演的MODIS气溶胶光学厚度(AOD)数据进行分析,研究了内蒙古气溶胶的时空分布特征.结果表明,内蒙古AOD值在东北部地区最高,其次为工业发达的中西部地区,最低值出现在大兴安岭及其山脉上空.全年AOD峰值出现在4月和6月,4月峰值主要受沙尘影响,6月峰值受季节雨带位移带来的湿度变化影响.中部气溶胶成分以沙尘气溶胶为主,而中西部和东北部气溶胶成分中存在大量人为源气溶胶.风场和相对湿度场与AOD值的年代际变化有关.     

17α-Ethynylestradiol biodegradation in different river-based groundwater recharge modes with reclaimed water and degradation-associated community structure of bacteria and archaea

This study investigated 17α-ethynylestradiol(EE2) biodegradation process and primary metabolic pathways associated with community structures of microorganism during groundwater recharge using reclaimed water. The attenuation rate is 1.58 times higher in wetting and drying alternative recharge(WDAR) than in continual recharge(CR). The primary biotransformation pathways of EE2 in WDAR system began with the oxidation of C-17 on ring D to form a ketone group, and D-ring was subsequently hydroxylated and cleaved. In the CR system, the metabolic pathway changed from the oxidation of C-17 on ring D to hydroxylation of C-4 on ring A, and ring A or B subsequently cleaved; this transition was related to DO, and the microbial community structure. Four hundred fifty four pyrosequencing of 16 s r RNA genes indicated that the bacterial communities in the upper layer of the WDAR system were more diverse than those found in the bottom layer of the CR system; this result was reversed for archaea. Unweighted Uni Frac and taxonomic analyses were conducted to relate the change in bacterial community structure to the metabolic pathway. Microorganism community diversity and structure were related to the concentrations of dissolved oxygen, EE2 and its intermediates in the system. Five known bacterial classes and one known archaeal class, five major bacterial genera and one major archaeal genus might be involved in EE2 degradation. The findings of this study provide an understanding of EE2 biodegradation in groundwater recharge areas under different recharging modes and can facilitate the prediction of the fate of EE2 in underground aquifers.     

汽柴油加氢装置分馏塔进料/反应产物换热器管束腐蚀原因分析

对汽柴油加氢装置分馏塔进料/反应产物换热器E-102/1、2腐蚀穿孔的原因进行了分析,采用XRD、金相分析、细菌培养试验等方法,分析了工艺、设备、设计3个方面的原因,认为停工保护与变更管理制度不完善是造成换热器腐蚀穿孔的根本原因,碱洗管理制度不完善、氯化物引起的点蚀以及微生物腐蚀等原因共同作用导致了换热器的腐蚀穿孔。     

泥河湾盆地于家沟遗址AMS-14C年代学研究及其考古学意义

于家沟遗址作为泥河湾盆地中唯一具有新旧石器工业过渡的典型遗址,为研究东亚旧石器向新石器时代过渡提供了理想的场所。本文通过于家沟遗址剖面沉积物(厚约550 cm)的加速器质谱法(AMS-~(14)C)年代测定,确定了于家沟剖面的年代跨度为16.19?—?2.43 ka BP,其中旧石器向新石器时代的转化时限为9.35 ka BP。该遗址中发现的最早陶器经同层位地层推测,其年代为13.60 ka BP,是目前中国北方发现的最早陶器。陶器的使用可能改善了古人类的生活条件;大量细石器反映出泥河湾盆地中采猎经济高度繁荣。因此,在晚更新世末期气候开始变暖的背景下陶器和细石器的出现一定程度推动了中国北方旧石器时代向新石器时代的转变。     

酸性矿山废水影响下水库细菌群落结构特征与环境因子关系

为揭示酸性矿山废水（Acid mine drainage,AMD）影响下水库水体中细菌群落结构特征及影响因子,对贵州省兴仁市3座受AMD影响与1座未受AMD影响水库样品进行了对比研究,利用16S rDNA高通量测序技术分析揭示细菌群落结构特征,并通过冗余分析（Redundancy analysis,RDA）探明影响水体细菌群落变化的主要环境因子.结果表明,受AMD影响水库水体中各主要阳离子（Ca²⁺、Na⁺、Mg²⁺、Fe²⁺、Mn²⁺、Cu²⁺、Zn²⁺、Ni²⁺）、SO₄^2-浓度及电导率值均高于未受AMD影响的水库,而DOC和pH值均低于未受AMD影响的水库.变形菌门（Proteobacteria）是受AMD影响水库水体的主要细菌门类,在3个受影响的水库中均占比95%以上.在属分类水平上,红杆菌属（Rhodobacter）、不动杆菌属（Acinetobacter）、假单胞菌属（Pseudomonas）和铁氧化细菌属（Ferrovum）是受AMD影响水库水体中的主要菌属;未受AMD影响水库水体细菌群落中,放线菌门（Actinobacteria）和变形菌门（Proteobacteria）为主要细菌门类,占比分别为48%和29%,主要菌属为发光杆菌属（Ilumatobacter）、不动杆菌属（Acinetobacter）.分析表明,受AMD影响水库细菌群落结构特征与未受AMD影响水库细菌群落存在明显差异,推测DOC、pH及Na⁺浓度对此差异起主导作用.本研究可为科学认识受AMD影响水体微生物群落与环境因子之间的关系提供依据.     

高压电网大气腐蚀在线监测技术进展

针对高压电网输变电设备的大气腐蚀问题,研究了几种典型的大气腐蚀监测技术。基于文献分析,探讨了电偶腐蚀电池、电化学阻抗谱、薄膜电阻传感器、石英晶体微天平以及交流导纳等腐蚀在线监测技术的研究进展,并对比分析了各种监测技术在电力设备中应用的优缺点。采用薄膜电阻探针和交流导纳技术可以实现高压输变电塔、架空地线以及变压设备大气腐蚀的在线监测。对输变电设备的大气腐蚀实施自动化在线监测,可以为设备安全诊断提供重要依据,与大数据分析结合,还可以为故障诊断与寿命评估提供参考。     

磺胺嘧啶胁迫下作物根际微生物群落结构响应

为了研究在磺胺类兽药胁迫下,两种作物在不同生长期根际微生物群落结构的响应,采用室内根际箱培养实验,测定玉米、小麦根际微界面土壤磷脂脂肪酸的量,研究在磺胺嘧啶（SD）胁迫下,不同作物根际土壤微界面微生物群落结构的空间变化.结果表明,SD对根际微生物活性的有抑制作用,且强度随浓度增加而增强.同一浓度SD作用下,根际微界面微生物生物量不同,在实验中,根际3mm和根室的微生物生物量最大,且二者之间差异不显著.不同微生物对根际效应敏感程度不同,细菌、革兰氏阳性菌、革兰氏阴性菌、蓝细菌和硫酸盐还原菌根际效应明显.在SD胁迫下,根际不同微界面土壤微生物群落结构变化明显.细菌、G⁺、G^-、放线菌的生物量,随SD浓度升高而下降,主要表现为抑制效应,而对真菌生物量则表现为激活效应,生物量增加. 小麦根际土壤真菌：细菌（F/B）随SD浓度的升高,比值增大,在高浓度（5mg/kg）胁迫下,F/B比值最大（0.74）,与对照差异显著（P < 0.05）,说明土壤污染修复能力增强,而sat/mono比值在高浓度SD胁迫下降低,说明微生物群落结构向有利于SD降解的方向转化.根际效应有助于SD的降解,在1mg/kg SD作用下,小麦根际土壤降解率为7.01%,而非根际土壤降解率仅为2.49%,不同作物表现出的根际效应强弱不同,玉米根际效应强于小麦.     

主流厌氧氨氧化工艺的运行优化及其微生物的群落变迁

通过高氨氮污水驯化成熟的CANON生物膜反应器处理低氨氮污水,试验分为3个阶段:(1)连续曝气无机配水阶段(0~59 d),曝气量30 m L·min-1,调整氨氮浓度为80 mg·L~(-1),厌氧氨氧化脱氮效率较低,第56 d时,TN去除负荷仅为0. 13kg·(m~3·d)~(-1).(2)连续曝气生活污水阶段(60~110 d),有机碳源的进入使得CANON反应器在79 d时TN去除负荷提升至0. 22 kg·(m~3·d)~(-1).(3)由于DO浓度较低,其氨氮去除率仅为75%,为进一步提高氨氮和TN的去除效果,第110 d时,进入间歇曝气生活污水阶段(110~160 d),提高曝气量为50 m L·min-1,曝气30 min,停曝30 min,第131 d时,氨氮去除率提高至86. 34%,TN去除率和去除负荷分别达到85. 87%和0. 30 kg·(m~3·d)~(-1),这说明间歇曝气策略可以提升CANON反应器的脱氮性能.同时在试验开始前(0d)、连续曝气无机配水阶段(56 d)和间歇曝气生活污水阶段(152 d)时分别取样进行了高通量测序,分析不同阶段的微生物群落变化,结果表明:(1)Candidatus Brocadia相比Candidatus Kuenenia在低氨氮无机配水和生活污水阶段中受影响较小;(2)Nitrosomonas和Nitrospira分别为AOB和NOB的优势菌种,生活污水阶段对Nitrosomonas影响较大,对Nitrospira影响较小;(3)反硝化菌属始终存在CANON反应器中,其中假单胞菌属(Pseudomonas)、副球菌属(Paracoccus)适应性最强,但各阶段相对丰度均不超过0. 5%.     

Biochemical responses of the freshwater microalga Dictyosphaerium sp. upon exposure to three sulfonamides

Sulfonamides (SAs) are common antimicrobial drugs, which are frequently detected in surface water systems, and are difficult to degrade, posing a potential threat to the aquatic environment. However, little is known about the potential adverse effects of SAs on non-target organisms (e.g., microalgae) in the aquatic ecosystem. In this study, the effect of SAs (sulfadiazine (SD), sulfamerazine (SM1), and sulfamethazine (SM2) at 1, 5, 20, and 50 mg/L concentrations, respectively) on the freshwater microalga Dictyosphaerium sp. was investigated, with respect to changes of biomass and chlorophyll a content and induction of extracellular polymer substances (EPS), including protein and polysaccharide contents. At the same time, the residue of SAs was determined. The results showed that Dictyosphaerium sp. was tolerant to the three SAs, and the chlorophyll a content in Dictyosphaerium sp. significantly decreased on day 7, followed by a “compensation phenomena”. The increase in protein and polysaccharide contents played a defensive role in Dictyosphaerium sp. against antibiotic stress, and there was a strong positive correlation between polysaccharide contents and antibiotic concentrations. Dictyosphaerium sp. exhibited 35%–45%, 30%–42%, and 26%–51% removal of SD, SM1, and SM2, respectively. This study is helpful to understand the changes of EPS in the defense process of microalgae under the action of antibiotics, and provides a new insight for the ecological removal of antibiotic pollution in natural surface water system.