Antibiotic resistance genes in manure-amended paddy soils across eastern China: Occurrence and influencing factors

• Manure fertilization resulted in antibiotic residues and increased metal contents. • The tet and sul genes were significantly enhanced with manure fertilization. • Soil physicochemical properties contributed to 12% of the variations in ARGs. • Soil metals and antibiotics co-select for ARGs. Pig manure, rich in antibiotics and metals, is widely applied in paddy fields as a soil conditioner, triggering the proliferation of antibiotic resistance genes (ARGs) in soil. However, comprehensive studies on the effects of manure fertilization on the abundance of ARGs and their influencing factors are still insufficient. Here, pig manure and manure-amended and inorganic-amended soils were collected from 11 rice-cropping regions in eastern China, and the accumulation of antibiotics, metals, and ARGs was assessed simultaneously. The results showed that manure fertilization led to antibiotic residues and increased the metal content (i.e., Zn, Cu, Ni, and Cr). Tetracycline and sulfonamide resistance genes (tetM, tetO, sul1, and sul2) were also significantly enhanced with manure fertilization. According to variance partitioning analysis, the most important factors that individually influenced ARGs were soil physicochemical properties, accounting for 12% of the variation. Significant correlations between soil nutrients and ARGs indicated that manure application enhanced the growth of resistant microorganisms by supplying more nutrients. Metals and antibiotics contributed 9% and 5% to the variations in ARGs, respectively. Their co-occurrence also increased the enrichment of ARGs, as their interactions accounted for 2% of the variation in ARGs. Interestingly, Cu was significantly related to most ARGs in the soil (r = 0.26–0.52, p<0.05). Sulfapyridine was significantly related to sul2, and tetracycline resistance genes were positively related to doxycycline. This study highlighted the risks of antibiotic and ARG accumulation with manure fertilization and shed light on the essential influencing factors of ARGs in paddy soils.     

Developing “precise-acting” strategies for improving anaerobic methanogenesis of organic waste: Insights from the electron transfer system of syntrophic partners

Methanogenesis is the last step in anaerobic digestion, which is usually a rate-limiting step in the biological treatment of organic waste. The low methanogenesis efficiency (low methane production rate, low methane yield, low methane content) substantially limits the development of anaerobic digestion technology. Traditional pretreatment methods and bio-stimulation strategies have impacts on the entire anaerobic system and cannot directly enhance methanogenesis in a targeted manner, which was defined as “broad-acting” strategies in this perspective. Further, we discussed our opinion of methanogenesis process with insights from the electron transfer system of syntrophic partners and provided potential targeted enhancing strategy for high-efficiency electron transfer system. These “precise-acting” strategies are expected to achieve an efficient methanogenesis process and enhance the bio-energy recovery of organic waste.     

Spatiotemporal variations of dissolved organic matter in a typical multi-source watershed in northern China: a fluorescent evidence

Environmental Science and Pollution Research - The amount of dissolved organic matter (DOM) in a multi-source watershed is important for complete management and assessing the river basin’s...     

五区电除尘技术试验研究及应用

五区电除尘技术是一种新型的电除尘器提效改造技术,由于其性能优良、工作可靠、稳定运行,工程投资少、施工周期短等优点而得到广泛应用。在模拟计算分析其阻力和对气流分布影响的基础上,试验研究其对不同粉尘的收尘性能,结果表明:五区电除尘技术可高效捕集微细、高比电阻粉尘,且设备阻力小,气流分布理想。     

攀钢炼钢厂提钒转炉浊环水水质稳定研究

在对转炉提钒浊环水质状况进行分析化验的基础上提出了水质调整措施,实施后有效地稳定了提钒浊环水质,改善了因提钒浊环酸性水质导致的缺陷,较好地满足了生产需要。     

水解-好氧工艺处理生活污水

采用水解 好氧工艺 ,替代了WSZ F地埋式设备处理生活污水。既解决了设备腐蚀 ,又克服了停留时间不足的问题 ,同时提高了处理效果。     

植物提取液处理恶臭气体的研究进展

介绍了近二十年来国内外关于植物提取液治理恶臭气体的研究成果,内容包括植物提取液的应用研究、除臭机理研究及植物提取液提取方法的研究;指出对恶臭气体中的胺类和醚类除臭机理、对植物提取液提取工艺优化的研究是今后研究的重点。     

钢板组合PEC柱-削弱截面钢梁组合框架抗震试验研究

为深入研究PEC柱-钢梁组合框架结构体系的抗震性能,设计了1榀两层单跨钢板组合截面PEC柱-削弱截面钢梁组合框架1∶2缩尺试件,并对其进行了低周往复荷载抗震试验。根据实测数据整理,得到了试验滞回特征曲线,并结合试验过程现象记录,分析了试件滞回特性、抗侧刚度退化规律、节点连接性能、耗能与延性和试件破坏模式等力学性能。研究结果表明:试件结构具有较高的承载力和较大的抗侧刚度;采取梁端截面削弱方式可实现梁端塑性铰位置远离节点区,且端板对穿螺栓连接能有效将梁端受拉翼缘拉力转化为对应边对节点区的压力,使得节点区形成了混凝土斜压带传力模式,提高了节点区抗震性能;试件滞回曲线较为饱满,在梁翼缘与端板连接焊缝存在施工缺陷情况下,其整体侧移、延性系数和等效黏滞阻尼比分别达到3.50%(推)/4.50%(拉)、2.92(推)/3.21(拉)和0.306,且承载力仍未下降至其极限承载力的85%,即试件结构具有良好的变形、抗震延性与耗能能力;该试件在循环往复荷载下呈现的破坏模式为梁削弱截面部位和PEC柱脚相继形成塑性铰的塑性机构。     

铜陵市资源利用与经济增长关系分析

资源利用与经济增长之间的关系是资源与环境经济学研究的重要领域。以安徽省铜陵市为例,尝试运用物质流分析方法以及最新发展的自回归分布滞后模型（ARDL）对铜陵市1990~2008年资源利用和实际GDP二者关系进行检验和分析。采用了物质流分析指标中直接物质投入来表征区域资源利用量。ARDL边界检验结果表明了资源利用和经济增长间存在稳定的长期均衡关系。进一步通过ARDL-ECM模型分析了区域经济增长对资源利用长期弹性系数和短期弹性系数,并揭示出资源利用对经济增长的短期和长期因果关系。研究结果表明当前资源投入在一定程度上拉动了铜陵经济增长。同时还对铜陵经济增长和资源保护战略提出了政策建议     

捞渣机圆柱滚子轴承套圈断裂原因分析

针对宁夏中宁发电有限责任公司1号炉捞渣机内导轮轴承断裂事故,对事故轴承进行宏观检查和材质分析,找出了事故的原因。结果表明:疲劳点蚀导致套圈脱落是导轮轴承圈断裂的直接原因;轴承套圈与轴装配不良、间隙过大是轴承套圈断裂的根本原因。