Production and characterization of novel thermo- and organic solvent–stable keratinase and aminopeptidase from Pseudomonas aeruginosa 4–3 for effective poultry feather degradation

Environmental Science and Pollution Research - Feather biodegradation is an important premise for efficient resource development and utilization, in which keratinase plays an important role....     

Novel approach for in situ recovery of cobalt oxalate from spent lithium-ion batteries using tartaric acid and hydrogen peroxide

Journal of Material Cycles and Waste Management - Recycling Co resource from spent lithium-ion batteries (LIBs) is significant for Co deficiency and environmental protection. A novel approach for...     

Exposure assessment of heavy metals (Cd,Hg, and Pb) by the intake of local foods from Zhejiang,China

Considering the environmental pollution, food safety is of great concern to the consumers. The present study was conducted to assess the health risk of cadmium (Cd), mercury (Hg), and lead (Pb) through the dietary intake in Zhejiang, China. Eight hundred and sixty two food samples including aquatic products, meat, vegetables, milk and dairy products, and cereal grains were analyzed. Only 2.44 % (Cd), 1.39 % (Hg), and 1.51 % (Pb) of the samples exceeded the maximum allowable concentration set by Chinese Ministry of Health. The average dietary intakes of Cd, Hg, and Pb were estimated to be 0.26, 0.14, and 0.55 μg/kg bw/day, respectively. Compared with the reference doses, the mean exposure of Cd, Hg, and Pb was all less than the tolerable intake value. Only at the 95th percentile level, Cd and Hg exposure exceeded the values of tolerable intakes by 40 and 277 %, respectively. It indicates that there is low health risk to the dietary exposure of Cd, Hg, and Pb for general people in Zhejiang province, China.     

Varying water column stability controls the denitrification process in a subtropical reservoir, Southwest China

Reservoirs are regarded as hotspots of nitrogen transformation and potential sources of nitrous oxide（N₂O）. However, it remains unclear how the hydrological conditions due to dam construction control the processes of nitrogen transformation in reservoir waters. To address this issue, we examined the spatial-temporal characteristics of nitrate concentrations, δ¹⁵N-NO₃^-, δ¹⁸O-NO₃^-, δ¹⁸O-H₂O, relative...     

A 700-year record of mercury in avian eggshells of Guangjin Island, South China Sea

Ancient eggshells over the past 700 years were extracted from an ornithogenic sediment profile on Guangjin Island, South China Sea. Based on SEM and nitrogen isotope analyses, we determined that neither post-depositional processes nor seabirds’ dietary changes had a large influence on eggshell Hg levels. The historical change of Hg in these eggshells was reconstructed. Eggshell Hg was a marker for past Hg deposition in marine environment. The eggshell Hg showed three small peaks at around 1300AD, 1600 AD and 1700-1750AD and rapid increase since 1800 AD. Before 1970 AD the Hg deposition in the Xisha area had global distribution characteristics, with increased Hg emissions due to global anthropogenic activities in industrial times. However, after 1970 AD, a further sharp increase up to present day occurred, implying that the Hg production center had gradually shifted from Europe and America to Asia.     

Inhibition of PCDD/F by adding sulphur compounds to the feed of a hazardous waste incinerator

Sulphur compounds, including (NH₄)₂SO₄ and pyrite, were tested as suppressants in a hazardous waste incineration facility. The test results suggested that adding sulphur compounds only slightly reduced PCDD/F stack emissions; this restricted effect was attributed to the release of fly ash in large amounts during the sulphur adding experiments, i.e., it was due to a malfunctioning of the baghouse filter. Nevertheless, for the combined flow of flue gas + fly ash a reduction of more than 50% was achieved for the total PCDD/F concentrations and the total toxic concentrations, and an even higher inhibition capability was observed for PCDD. Also, a simulation of the thermodynamic equilibrium conditions by sulphur dioxide was conducted in the domain of experimental interest. Deactivation of catalysts, which promote PCDD/F formation, was found to be the dominant inhibition mechanism in low temperature PCDD/F formation. SO₂ could also inhibit the formation of molecular Cl₂ via the Deacon reaction, but that was not the main reason for inhibition.     

21世纪长江黄河源区径流量变化情势分析

以长江、黄河源区为研究对象,应用大尺度半分布式水文模型(VIC),结合江河源区气象站多年实测温度、降水数据,检验了VIC模型的适用性。模型能较好模拟江河源区地表径流,其Nash系数和相关系数分别达到了0.853 3和0.930 2（长江源区）,0.889 2和0.924 8（黄河源区）。基于率定后的VIC模型,运用高分辨率的动力降尺度气象强迫资料,分析了未来气候变化情景下,江河源区径流量可能变化趋势。结果表明,未来30~50 a,长江、黄河源区年均径流量将分别增加858%、919%;未来80~100 a,长江、黄河源区年均径流量将分别增加1716%、721%。相对于2030~2049年而言,尽管年均降水增加006 mm/d,但是黄河源区2080~2099年径流量却将减少1.98%。运用植被情景假设及2030~2049年动力降尺度气象资料,模拟分析了植被变化对江河源区地表径流的影响。从4种地表覆被情景假设可以看出,林地地表覆被产生径流量最小,裸地最大。
     

影响太子河流域鱼类空间分布的不同尺度环境因子分析

鱼类的退化受到不同类型环境因子的影响,为制定更合理的鱼类保护计划,本研究采用了非度量多维标度法(NMS)研究了太子河流域不同尺度环境因子对鱼类空间分布的影响.鱼类聚类结果发现太子河流域鱼类可分为3种分布类型区,即上游森林及支流源头区、中游山地区和下游平原区.NMS分析表明太子河流域鱼类空间分布受到流域、河段和微生境这3种尺度上环境因子的影响,海拔、河流等级和土地利用在流域尺度上对鱼类分布表现出显著影响,速度与深度结合等级、栖境复杂性等级和电导率等因子在河段尺度上表现出显著作用,底质等级是在微生境尺度上具有显著作用.因此,在流域鱼类保护管理中应考虑不同尺度上环境因子的影响.     

汽车灯具检测常见问题分析

随着汽车工业的飞速发展,汽车车灯照明效果的检测越来越被加以重视。本文主要介绍了汽车灯具测试中的若干注意事项,并对汽车灯具认证中容易出现的不合格项目进行了分析,在汽车灯具检测领域中具有一定的参考价值。