焦化厂PAHs污染土壤中微生物群落多样性特征

土壤中微生物在多环芳烃(PAHs)的降解过程中起着重要作用。以华北某焦化厂土壤为研究对象,在5个采样点(每个点分6层)采集30个土壤样品,分析土壤环境因子(理化性质和PAHs浓度)、微生物丰度及群落结构,探讨土壤中微生物组成与环境因子间的关系。结果表明:土壤中细菌丰度为5.33~8.89,与土壤深度呈显著负相关(P<0.01),与土壤PAHs、有机碳、全氮浓度呈正相关(P<0.05);土壤中优势细菌类群(门)为变形菌门(Proteobacteria),其相对丰度占比最高达90%,其次是绿弯菌门(Chloroflexi)、放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)和酸杆菌门(Acidobacteria),其占门水平分类细菌数量的64%~97%;细菌类群与环境因子冗余分析表明,焦化厂土壤中细菌群落结构特征是PAHs污染和环境因子共同作用的结果,其中土壤pH与速效钾、PAHs、全氮浓度对土壤细菌群落组成影响明显,PAHs潜在降解菌Proteobacteria丰度与PAHs、全氮、有效磷、速效钾、有机碳浓度呈正相关。     

聚乙烯微塑料对尼罗罗非鱼(Oreochromis niloticus)生长、抗氧化、免疫和肠道微生物的影响

近年来,微塑料作为一类新型污染物引起了国内外的广泛关注。笔者研究了0、0.01、0.1和5 mg·L^-1的高密度聚乙烯微塑料(high-density polyethylene, HDPE, 61～83 μm)胁迫尼罗罗非鱼(Oreochromis niloticus)28 d后的毒性效应。结果表明,HDPE微塑料暴露28 d后,尼罗罗非鱼的成活率、增重率、肝体比与对照组相比无显著差异(P>0.05)。尼罗罗非鱼肝脏丙二醛(MDA)含量在0.01 mg·L^-1和5 mg·L^-1 HDPE暴露组中显著高于对照组(P<0.05);谷胱甘肽转移酶(GST)活性在5 mg·L^-1暴露组中显著高于对照组(P<0.05);与对照组相比,暴露组尼罗罗非鱼肝脏的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和碱性磷酸酶(AKP)活性,以及鱼脑的乙酰胆碱酯酶(AChE)活性无显著差异(P>0.05),而在0.1 mg·L^-1暴露组中酸性磷酸酶(ACP)活性显著高于对照组(P<0.05)。尼罗罗非鱼暴露于HDPE微塑料28 d后,肠道菌群16S rDNA测序结果表明,样品中共获得465 336条优化序列,操作分类单元(OTU)总数854个;与对照组相比,微塑料暴露组尼罗罗非鱼肠道中变形菌门、厚壁菌门、拟杆菌门和蓝细菌门的丰度减少,放线菌门丰度增加,但无显著性差异;在5 mg·L^-1 HDPE微塑料暴露组中,衣原体门的丰度显著高于对照组(P<0.05)。综上可知,高浓度微塑料暴露能够对尼罗罗非鱼产生氧化胁迫并影响肠道菌群群落结构。研究结果可为揭示聚乙烯对水生生物的毒性效应及其潜在的生态风险评估提供科学依据。     

基于物质流分析的建筑垃圾产生量预测

针对建筑垃圾产生量激增但其统计数据缺失问题,基于1stOpt拟合平台和Visual Basic编程软件,构建城镇住宅和非住宅建筑垃圾产生量动态预测模型,定量模拟不同建筑寿命情景下建筑垃圾产生量及其组分的变化趋势。结果表明:我国城镇住宅建筑和非住宅建筑存量面积分别在2058年和2064年达到峰值(657.35亿和569.41亿m²)。在短、中、长建筑寿命情景下,住宅和非住宅建筑的新建面积均在21世纪20年代达到峰值,拆除面积峰值将在21世纪下半叶实现。在短、中、长寿命3种情景下,我国城镇住宅建筑垃圾总产量分别于2072年、2081年和2100年达到峰值(28.69亿、21.71亿和16.50亿t);非住宅建筑垃圾总产量分别于2077年、2084年和2100年达到峰值(26.25亿、20.29亿、15.48亿t)。2000年之前,建筑垃圾主要成分为施工垃圾,2000年之后,以拆除垃圾为主,至2100年拆除垃圾占比达98%。其中,混凝土、砖块、钢铁分别占44%~71%、22%~51%、0.50%~2.89%,其他成分占2.76%~4.68%。综合考虑建筑流量发展趋势和建筑垃圾产生特征,政府部门应宏观调控减缓人均建筑面积增长速度,延长建筑使用寿命,提高建筑垃圾循环利用率和二次建材原料的市场消纳量,从而减少建筑垃圾产生量,降低建筑垃圾对生态环境的破坏。     

Eutrophication of Two Lakes in Kinmen Island (Taiwan)

Water quality was monitored for 12 months in Lake Tai and Lake Zon on Kinmen Island, Taiwan, and physico-chemical conditions were analyzed. No vertical temperature stratification was observed in these shallow lakes. pH is neutral to alkaline and associated with vigorous algal growth. Nitrogen levels are high and present in various forms due to progressive nitrification. Green and blue-green algae play an important part in the process of nitrification.

Assessment of lake eutrophication was made by the use of the N:P ratio, the Trophic State Index (TSI) and the US EPA Eutrophic Screening Model. the result of these calculations indicates eutrophic conditions in both lakes. It is advised that lake restoration be initiated and available techniques are listed.     

湖北稻区冬半年农业资源特点和冬季农业开发

本文论证了湖北稻区冬半年的农业资源及其特点,讨论了开发本区冬季农业的意义、发展方向及其关键措施。     

衡阳地区水资源特征及其开发利用

本文分析了衡阳地区地表水资源特征和地下水资源类型与特征，并根据工农业生产的发展，需水与供水间的矛盾及旱涝灾害等情况，对水资源的开发利用途径进行了探讨。     

Winter Soil Respiration from Different Vegetation Patches in the Yellow River Delta, China

Vegetation type and density exhibited a considerable patchy distribution at very local scales in the Yellow River Delta, due to the spatial variation of soil salinity and water scarcity. We proposed that soil respiration is affected by the spatial variations in vegetation type and soil chemical properties and tested this hypothesis in three different vegetation patches (Phragmites australis, Suaeda heteroptera and bare soil) in winter (from November 2010 to April 2011). At diurnal scale, soil respiration all displayed single-peak curves and asymmetric patterns in the three vegetation patches; At seasonal scale, soil respiration all declined steadily until February, and then increased to a peak in next April. But, the magnitude of soil respiration showed significant differences among the three sites. Mean soil respiration rates in winter were 0.60, 0.45 and 0.17 μmol CO(2) m(-2) s(-1) for the Phragmites australis, Suaeda heteroptera and bare soil, respectively. The combined effect of soil temperature and soil moisture accounted for 58-68 % of the seasonal variation of winter soil respiration. The mean soil respiration revealed positive and linear correlations with total N, total N and SOC storages at 0-20 cm depth, and plant biomass among the three sites. We conclude that the patchy distribution of plant biomass and soil chemical properties (total C, total N and SOC) may affect decomposition rate of soil organic matter in winter, thereby leading to spatial variations in soil respiration.     

浅议环境监测档案的建立和运用

通过分析目前环境监测站监测档案建立和运用中存在的问题,探讨了档案的建立方法及在环境监测和环境管理中的运用。