CO2 dynamic of Lake Donghu highlights the need for long-term monitoring

Environmental Science and Pollution Research - Inland freshwater lakes have been widely considered as significant sources of CO2 to the atmosphere. However, long-term measurements of CO2 dynamics...     

A comparison of antibiotics,antibiotic resistance genes,and bacterial community in broiler and layer manure following composting

Animal manure is an important source of antibiotics and antibiotic resistance genes (ARGs) in the environment. However, the difference of antibiotic residues and ARG profiles in layer and broiler manure as well as their compost remains unexplored. In this study, we investigated the profiles of twelve antibiotics, seventeen ARGs, and class 1 integrase gene (intI1) in layer and broiler manure, and the corresponding compost at large-scale. Compared with layer manure, broiler manure exhibited approximately six times more residual tetracyclines, especially chlortetracycline. The relative abundances of qnrS and ermA genes in broiler manure were significantly higher than those in layer manure. The concentration of tetracyclines not only had a significantly positive correlation with tetracycline resistance genes (tetA and tetC) but was also positively correlated with quinolone resistance (qepA, qnrB, and qnrS) and macrolide resistance (ermA and ermT). Most ARGs in manure were reduced after composting. However, the relative abundance of sulfonamide resistance gene sul1 increased up to 2.41% after composting, which was significantly higher than that of broiler (0.41%) and layer (0.62%) manure. The associated bacterial community was characterized by high-throughput 16S rRNA gene sequencing. The relative abundances of thermophilic bacteria had significant positive correlations with the abundance of sul1 in compost. The composting has a significant impact on the ARG-associated gut microbes in poultry manure. Variation partitioning analysis indicated that the change of bacterial community compositions and antibiotics contributed partially to the shift in ARG profiles. The results indicate that at industry-scale production broiler manure had more antibiotics and ARGs than layer manure did, and composting decreased most ARG abundances in poultry manure except for sulfonamide resistance genes.

     

Synthesis of Ni-doped anatase TiO2 single crystals loaded on wood-based activated carbon for enhanced photodegradation of triphenylmethane dyes

Environmental Science and Pollution Research - In this work, the Ni-doped anatase TiO2 single crystals loaded on activated carbon (Ni-T/AC) were synthesized by a sol–gel method. The chemical...     

Effects of tea polyphenols on the activities of antioxidant enzymes and the expression of related gene in the leaves of wheat seedlings under salt stress

Environmental Science and Pollution Research - Longchun 30, a new wheat variety, was used to investigate seedling growth, element absorption, and antioxidant response under 150 mM NaCl and tea...     

Life cycle assessment of environmental impact on municipal solid waste incineration power generation

Environmental Science and Pollution Research - Municipal solid waste (MSW) incineration power generation is an important treatment technology, which has been widely concerned in recent years. It is...     

Explanation of heavy metal pollution in coal mines of china from the perspective of coal gangue geochemical characteristics

Environmental Science and Pollution Research - In the process of coal gangue surface accumulation and underground filling disposal, the heavy metals contained in coal gangue will inevitably...     

重庆缙云山4种典型植被覆盖下汞的释放通量及影响因素

为了揭示不同植被覆盖下土壤/大气界面释汞通量及其交换特征,在缙云山国家级自然保护区内选择4种典型植被覆盖类型(常绿阔叶林、楠竹林、灌木林以及草地)为研究对象,连续同步监测不同植被覆盖下土/气界面汞释放通量,同时考察各环境因子对土壤释汞的影响.结果表明,缙云山在4种不同植被覆盖下土壤汞释放通量具有明显的差异,总体表现为楠竹林[17.77 ng·(m~2·h)~(-1)]草地[17.58 ng·(m~2·h)~(-1)]灌木林[16.87 ng·(m~2·h)~(-1)]常绿阔叶林[14.32 ng·(m~2·h)~(-1)];不同植被覆盖下土壤释汞通量在季节变化上呈现相似的规律性,但不同植被覆盖类型之间也存在明显差异,主要体现在暖季汞释放通量高于冷季;缙云山地区不同林植被覆盖下土壤释汞通量存在明显的日变化;气象因素光照强度、气温、土温和相对湿度,对土/气界面汞释放通量影响也不相同,气温为常绿阔叶林,灌木林与楠竹林的主要影响因子,光照强度为草地的主要影响因子.     

不同锆负载量锆改性膨润土对水中磷酸盐吸附作用的对比

通过实验对比考察了不同锆负载量的锆改性膨润土对水中磷酸盐的吸附作用.结果表明,锆改性膨润土对水中磷酸盐的吸附动力学过程符合准二级动力学模型,整个过程可以分为快速吸附阶段、缓慢吸附阶段和平衡吸附阶段,其中缓慢吸附阶段的吸附速率受膜扩散和颗粒内扩散所控制.锆改性膨润土对水中磷酸盐的吸附等温实验数据可以采用Langmuir、Freundlich、Sips和Dubinin-Radushkevich等温吸附模型进行拟合.实验条件下,磷酸盐吸附性能随pH增加而降低.溶液共存的Na~+、K~+和Ca~(2+)促进了锆改性膨润土对磷酸盐的吸附,并且Ca~(2+)的促进作用远远大于Na~+和K+,而溶液共存的HCO-3和SO2-4一定程度上抑制了锆改性膨润土对磷酸盐的吸附.锆改性膨润土吸附水中磷酸盐的主要机制为配位体交换并形成内层磷酸盐配合物.锆改性膨润土对水中磷酸盐的吸附能力随着锆负载量的增加而增加,而锆改性膨润土中单位质量ZrO_2对水中磷酸盐的吸附量则随着锆负载量的增加而降低.当ZrO_2负载量由3.61%增加到13.15%时锆改性膨润土的最大单层单位吸附量(以P计)显著地由3.83 mg·g~(-1)增加到9.03 mg·g~(-1),而继续增加ZrO_2负载量至19.63%时锆改性膨润土的最大单层单位吸附量则缓慢地提高到9.66 mg·g~(-1)(以P计).当ZrO_2负载量由3.61%逐渐增加到19.63%时,锆改性膨润土中单位质量ZrO_2的磷酸盐最大吸附量[m(P)/m(ZrO_2)]由106 mg·g~(-1)逐渐下降到49.2 mg·g~(-1).综合考虑吸附剂的经济成本和吸附容量,ZrO_2负载量为13.15%锆改性膨润土更为适合作为吸附剂去除水中磷酸盐.     

原子吸收法测定海水中铁含量的不确定度评定

为了保证海水中铁元素含量的检测质量,更好地深入了解铁在整个海水体系的生物地球化学中扮演的角色,需科学地评定检测结果的分散性。文章依据《测量不确定度的评定与表示》(JJF1059-1999)的理论,以浙江近海海水为例,评定原子吸收法测定海水中铁含量的不确定度。测得浙江近海样品中铁的浓度为5.2μg/L,扩展不确定度U=0.8μg/L(k=2)。通过对各不确定度分量进行评定发现,利用该方法测定海水中铁含量时,对其合成标准不确定度的主要贡献来自于样品制备过程,尤其是萃取过程。     

人工快渗一体化设备在农村污水处理中的应用

针对农村污水的特点,结合湖北十堰地区农村污水处理工程案例,分析了以人工快渗技术为核心的一体化设备在实际应用中的运行效果和工艺优势。经过实际运行监测,工程处理出水主要水质指标可达到GB 18918—2002《城镇污水处理厂污染物排放标准》一级A排放标准,并且该工艺设备具有运行成本低、抗冲击负荷能力强、运行管理方便等优点,可有效地解决目前农村地区由于资金、技术、人才等因素限制造成的污水处理能力低和管理水平低的问题,是一种适合我国农村地区污水处理的工艺设备。