The effect of municipal sludge compost on the mobility and bioavailability of Cd in a sierozem-wheat system in an arid region northwest of China

The effect of sewage sludge on the mobility and the bioavailability of trace metals in plant-soil systems have aroused wide interested and been widely explored. Based on a wheat-cultivating experiment, the effect of municipal sludge compost (MSC) on the mobility and bioavailability of Cd in a soil-wheat system was studied. With the application of MSC, soil organic matter (SOM), total nitrogen (TN), and total phosphorus (TP) in the soil increased significantly, while concentrations of trace metals (Cu, Zn, Ni, Pb, Cd) were below the China’s minimum thresholds. The application of MSC could improve wheat growth. The application of MSC at the rate of 0.5 % had no significant effect on the chemical fraction distribution of Cd in soil. In two soil treatments, Cd mainly existed in the labile chemical fractions (exchangeable chemical fraction (EXCF) and carbonate chemical fraction (CABF)). However, the application of MSC could reduce accumulation of Cd by wheat. Cd contents in each part of the MSC-applied wheat were significantly less than that of non-MSC-applied wheat. In the tested soils, the extractable concentrations decreased in the order: EDTA > MgCl₂ ≈ NH₄OAc > DTPA. There were no significant differences between soil treatments in the amounts of extractable Cd when the extraction was done under neutral conditions, although significant differences were observed when the extraction was done under alkaline conditions. In this study, the DTPA extraction procedure provided a good indication of Cd bioavailability. Our results suggest that, in the short term at least, amending soils with MSC may benefit crop dry matter production while not increasing the risk of human exposure to Cd through consumption of wheat grown on MSC-amended soils.     

模拟酸雨对毛竹入侵阔叶林缓冲区土壤细菌群落多样性的影响

为了分析酸雨对毛竹入侵阔叶林缓冲区土壤细菌群落多样性的影响,以浙江省天目山国家级自然保护区毛竹扩张形成的竹阔混交林为研究对象,选取T₁（pH=4.0）、T₂（pH=2.5）两个模拟酸雨梯度,并以pH=5.5为对照（CK）,应用Illumina MiSeq高通量测试技术分析不同强度酸雨胁迫下土壤细菌群落组成和多样性变化及其关键影响因素.结果表明:①随着酸雨强度增加,竹阔混交林土壤w（TN）（TN为总氮）、w（OC）（OC为有机碳）、C/N和w（AN）（AN为碱解氮）显著升高,而pH、w（DOC）（DOC为可溶性有机碳）、w（MBC）（MBC微生物量碳）和w（MBN）（MBN为微生物量氮）显著下降（P < 0.05）.②与CK相比,模拟酸雨处理（T₁、T₂）显著降低了细菌群落的OTUs数量、Chao1指数和Ace指数（P < 0.05）.③竹阔混交林土壤细菌包括34门96纲247目401科698属,其中变形菌门、酸杆菌门、绿弯菌门、放线菌门为3种处理下共有的优势菌门（相对丰度>1%）.变形菌门和放线菌门相对丰度在CK处理下最高,酸杆菌门和绿弯菌门相对丰度在T₂处理下最高.与CK相比,Arthrobacter属和Elsterales属相对丰度变化显著,可作为酸雨胁迫下土壤细菌群落结构变化的指示种.主坐标（PCoA）分析和相似性检验结果显示,模拟酸雨改变了土壤细菌群落结构.④冗余分析（RDA）和相关性分析表明,不同酸雨处理的竹阔混交林土壤细菌多样性与土壤pH、w（TN）密切相关（P < 0.05）.研究显示,不同模拟酸雨处理下土壤细菌群落结构和多样性有明显差异,主要可能受到土壤pH、w（TN）的影响.      

地下车库空气中苯系物浓度的时间分布特征与污染评价

采用气相色谱法定量分析了地下车库空气中苯系物(苯、甲苯、二甲苯)的浓度并于不同时间段采集地下车库的空气样品,研究了地下车库内苯系物的浓度随时间的变化特征及污染状况。研究结果表明:①在实验色谱条件下,用外标法测定苯系物的准确度较高,回收率为90%~110%;②苯系物浓度随时间的变化呈现明显的周期性,苯系物单体浓度与总量浓度随时间的分布特征相似,表现为早晨的浓度大于中午及傍晚;③苯系物总量和单体浓度远远高于室外;④地下车库苯系物浓度低于中国室内空气质量标准限值,但检测结果表明地下车库存在苯系物的污染,长期累积对人体健康构成潜在威胁。     

糖蜜、淀粉与乳品废水厌氧发酵法生物制氢

采用连续流厌氧发酵法研究了糖蜜废水、淀粉废水与牛奶废水生物制氢,讨论了有机物中3大类物质的厌氧发酵产氢的可行性,并对几种底物的产氢稳定性进行了探讨.结果表明,糖蜜废水与淀粉废水都是较好的厌氧发酵法生物产氢底物,在3大类有机物中碳水化合物是目前技术条件下最具有可能性的原材料.在碳水化合物中,溶解性好的糖比溶解性差的淀粉在目前的技术条件下具有生物产氢可行性,而淀粉比溶解性糖更具有产氢前景.不同底物厌氧生物制氢的生态位范围有所不同,对于溶解性好的糖,稳定运行的工程控制参数为pH 4.5±0.3,而溶解性较差的淀粉废水为pH 4.0±0.2;厌氧发酵产氢的ORP值也随底物的不同而不同,但总体必须低于-220mV,在-300mV左右时较好.牛奶废水不适用于作为CSTR反应器中发酵法生物制氢底物.     

HPLC-ESI-MS测定地表水中典型全氟化合物方法

利用固相萃取技术,基于高效液相色谱一质谱仪,建立检测水样中典型全氟化合物（全氟辛基磺酸、全氟辛酸、全氟壬酸）的分析方法。从线性范围、定量检测限、回收率、空白试验以及实际样品测定方面,验证了分析方法的可行性。该分析方法降低了仪器成本,操作简便,有利于全氟化合物监测项目的推广。     

Natural resources,population aging,and environmental quality: analyzing the role of green technologies

Environmental Science and Pollution Research - Depletion of natural resources and population aging are the two most critical challenges for environmental sustainability. However, the research that...     

PM2.5 exposure induces age-dependent hepatic lipid metabolism disorder in female mice

Particulate matter exposure has been described to elevate the risk of lung and cardiovascular diseases.An increasing number of recent studies have indicated positive correlations between PM_2.5(the fraction of airborne particles with an aerodynamic diameter less than2.5 μm) exposure and the risk of liver diseases.However,research on the effects of PM_2.5exposure on liver fat synthesis,secretion,and clearance mechanisms under normal diet conditions is limited,and whether these...     

辽宁西南典型城市冬季大气细颗粒物水溶性无机离子污染特征及来源解析

本研究于2018年12月3日-2019年1月1日在辽宁省西南典型城市葫芦岛市和朝阳市分别布设3个城区采样点,在区域传输点龙屯水库布设1个采样点,采集大气细颗粒物PM2.5样品(n=201).使用离子色谱检测样品中的Na+、Mg2+、Ca2+、K+、NH4+、SO42-、F-、Cl-和NO3-的质量浓度.观测期间PM2....     

复合自养反硝化材料处理低碳氮比硝酸盐污水

作为一种典型的硝酸盐污水,低碳氮比硝酸盐污水的存在具有广泛性,且对生态环境和居民健康带来的危害日益突出.本研究构建了复合硫自养反硝化(CSAD)体系,基于硫-碳酸钙型复合材料与微生物,进行低碳氮比硝酸盐污水的深度处理,分析了材料投加量、粒径以及进水硝酸盐浓度对CSAD的影响,并探究了硝酸盐去除的动力学行为.结果 表明,...     

硅酸盐-磷酸盐对酸法地浸采铀退役采区模拟地下水的修复

为探索酸法地浸采铀退役采区地下水的原位修复技术,本研究先从西北某酸法地浸采铀退役采区采取地下岩心样,同时制备了酸法地浸采铀退役采区地下水模拟水样,构建模拟修复反应的微模型;再向微模型中分别加入硅酸钠溶液、磷酸二氢钾溶液、硅酸钠-磷酸二氢钾混合溶液以考察其对地下水的修复效果。结果表明：加入的硅酸钠-磷酸二氢钾与铀反应形成了胶磷钙铁矿(Ca₆Fe₉(PO₄)₉O₆(H₂O)₆.3H₂O)、偏钠铀矿物(Na(UO₂)(PO₄).3H₂O)和(NaPUO₆.3H₂O)三种矿物;沉淀物中铁锰氧化物交换态铀的含量增加到了41%;铀的去除率达到了99.72%。