Biochemical responses,growth and reproduction of earthworm in low density polyethylene (LDPE)

There is an unprecedented production of plastic that is accelerating its disposal while affecting the fitness of the terrestrial as well as the aquatic environment. The term microplastics refers to plastic fragments that are less than 5 mm in size and are widely distributed in the environment. Therefore, the present study intends to explore the biological response of earthworms (Eisenia fetida) toward different concentrations of low-density polyethylene. E. fetida treated with low-density polyethylene concentration (Control), 250 mg kg⁻¹, 1000 mg kg⁻¹, 6000 mg kg⁻¹, 12,000 mg kg^−1, and 25,000 mg kg⁻¹. The above ratios were thoroughly mixed with 1kg of artificial soil and tested for growth, reproduction (cocoons and hatchling count), and enzymatic activities namely superoxide dismutase, guaiacol peroxidase, glutathione-S-transferase, and glutathione reductase and molecular docking studies. No mortality was observed during the exposure period at any concentrations. On the 28th day, when compared to the control the highest decrease in body weight of earthworms was observed in 25,000 mg (28.4%) followed by 12,000 mg (12.2%) and 6000 mg (3.4%). The cocoon and hatchlings significantly declined as the dose of microplastics increases. Enzymatic activity such as SOD and POD showed declined trend as the dose increased, while GST and GR increased with an increase in microplastic concentrations on 28th day. Furthermore, molecular docking showed that LDPE can modulate the activity of all four enzymes significantly.     

藏东多曲河流域锶富集水化学特征及控制因素

分析高原河流地表水中锶(Sr)富集的水化学特征及其影响因素,有助于指导水资源的合理开发利用和生态环境保护.以金沙江多曲河流域地表水为例,采集地表水样品23组,综合利用相关分析、主成分分析、Gibbs模型和离子比等方法,分析该区地表水中Sr²⁺富集的水化学特征及控制因素,识别主要离子的物质来源.结果表明,多曲河流域地表水阳离子主要以Ca²⁺和Mg²⁺为主,阴离子以HCO₃^-为主.该流域水化学类型以HCO₃-Ca型为主,其次为HCO₃-Ca·Mg型.主成分分析揭示了影响多曲河水质演化的3个主成分因子,碳酸盐岩风化溶解是控制多曲河水化学组成的主要因素.ρ(Sr²⁺)超过0.40 mg·L^-1的富Sr水点占样品总量的30.43%.区内分布的闪长岩及花岗岩为多曲河流域Sr²⁺富集提供了物质基础.Sr²⁺与Ca²⁺相关性较高,二者存在伴生...     

中国生态环境质量与人类活动耦合机制及其影响因子

在可持续发展大背景下,深入探究中国生态环境质量与人类活动耦合机制并明确其影响因子,可为未来中国实现可持续发展目标提供一定的科学参考.运用趋势分析、耦合协调度、LMDI模型和最优参数地理探测器模型对中国生态环境质量与人类活动耦合机制进行探究和评价.结果发现:①在研究期间,中国耦合协调度、人类活动和生态环境质量均为增长趋势.人类活动和耦合协调度在空间上以胡焕庸线为界,呈现“东高西低”的分异规律.生态环境质量则表现出“南高北低”分异规律.②中国耦合协调类型转化的整体趋势为由低级向更高级的耦合协调类型转移.③基于最优参数地理探测器和LMDI模型分别发现,胡焕庸线以东绝大部分省区的耦合协调度其主导因子分别为社会经济因子和综合协调指数,该线以西绝大部分省区的耦合协调度主导因子分别为自然环境因子和耦合度.④评价人类活动变化对生态环境质量的影响,发现胡焕庸线以东主要为有利开发和有效保护类型,胡焕庸线以西主要为破坏开发和无效保护类型.胡焕庸线东西两侧地区应分别根据当地影响耦合协调度的先决条件以及人类活动和生态环境质量的相对关系,因地制宜选择优先发展地区,积极调整发展策略,走向生态环境质量与人类活动高级协调发展的可持续发展道路.     

企业生产活动对场地地下水环境质量的影响及分析

企业对所在场地地下水定期开展监测,能够及时发现异常,预防地下水污染。本文结合飞机制造企业生产活动及污染物排放特点,对场地地下水进行监测布点,并分析地下水可能的污染途径,发现良好的管理手段和环境特性能保证场地地下水环境质量,而企业生产活动直接影响着场地地下水环境质量。     

山东省省级自然保护区人类活动遥感监测与评价

基于2018年高分系列遥感影像数据,提取山东省省级自然保护区人类土地利用活动信息,探讨人类活动对山东省省级自然保护区的影响。结果表明,自然保护区人类活动总面积占保护区总面积的22.2%,人类活动影响指数介于0~0.01368。不同类型的自然保护区人类活动面积不同,主要影响因子差异明显,森林生态类保护区以农业用地为主,内陆湿地类保护区以养殖场为主。内陆湿地类保护区是受到人类干扰程度最为严重的保护区类型,野生动物类保护区受到人类影响最小。     

亚高山旅游景区岩溶地下水水化学动态变化及其影响因素

岩溶地下水是岩溶区重要的水资源,因岩溶水文系统具有敏感性和脆弱性,其一旦遭受污染便很难再恢复。以重庆亚高山金佛山水房泉为例,通过计算2008年和2016年各水化学参数的浓度增降幅度和地球化学敏感性指数,对比分析各水化学参数及其地球化学敏感性变化特征。结果表明：水房泉水化学类型为Ca-HCO₃型,受水 岩作用控制。旅游活动产生的生活污水自2013年起被分成两条管道,住宿排污经过泉域内化粪池的沉淀降解后排入地下,使得2016年水房泉中K⁺、Na⁺、PO₄^3-浓度较2008年降低,显示化粪池对污染物具有有效的调节作用;而餐饮排污未经处理仍直接排入地下,导致流域出口水房泉中Cl^-、NO₃^-浓度呈翻倍增长,水质恶化。污水还加剧了碳酸盐岩的溶蚀,地下水中HCO₃^-、Ca²⁺、Mg²⁺浓度上升。由于旅游高峰期与非高峰期的游客量差距逐渐缩小,2016年各化学组分的敏感性指数多低于2008年,地下水受旅游活动影响的时间变长;分别对比不同水文年各主量组分的敏感性指数大小和离子当量浓度大小,发现2008年两者排序基本一致,而2016年较为混乱,这可能表明研究区地下水系统逐渐从有序转向无序的状态,稳定性被破坏,熵值增大。     

Antimicrobial activities of flavonoids against bamboo-destroying fungi and molds

It is well-known that Poria vaporaria (Pers.:Fr.) Cooke, Paecilomyces variotii Bainier and Aspergillus niger are fungi and molds which destroy bamboo. The aim of this study was to compare the effectiveness of antibacterial activity of 16 flavonoids in preventing the actions of these three bamboo-destroying fungi and molds (Poria vaporaria (Pers.:Fr.) Cooke, Paecilomyces variotii Bainier and Aspergillus niger). The results showed that baicalein(1) exerted the highest inhibitory effect on Poria vaporaria (Pers.:Fr.) Cooke and Paecilomyces variotii Bainier indicating that baicalein(1) may be considered as a potential agent to develop as natural bactericide to preserve natural bamboo.     

Iron content in groundwaters of Visakhapatnam environs, Andhra Pradesh, India

Trace elements are essential for human health. However, excess concentrations of these elements cause health disorders. A study has been carried out in Visakhapatnam environs, Andhra Pradesh, India to ascertain the causes for the origin and distribution of iron content in the groundwaters. Fifty groundwater samples are collected and analyzed for iron. The content of iron ranges from 400 to 780 μg/l. A comparison of groundwater data with rock and soil chemistry suggests that the concentration of iron (400–530 μg/l) in the groundwaters is derived from the rocks and soils due to geogenic processes. This concentration is taken as a natural occurrence of iron in the groundwaters of the study area for assessing the causes for its next higher content (>530 μg/l). Relatively higher concentration of iron (540–550 μg/l) is observed at some well waters, where the wells are located nearby municipal wastewaters, while the very high concentration of iron (610–780 μg/l) is observed in the industrially polluted groundwater zones, indicating the impact of anthropogenic activities on the groundwater system. These activities mask the concentration of iron caused by geogenic origin. Hence, both the geogenic and anthropogenic activities degrade the groundwater quality. Drinking water standards indicate that the iron content in all the groundwater samples exceeds the permissible limit (300 μg/l) recommended for drinking purpose, causing the health disorders. Necessity of close monitoring of groundwater quality for assessing the impact of geogenic and anthropogenic sources with reference to land use/land cover activities is emphasized in the present study area to protect the groundwater resources from the pollution.     

德兴铜矿周边地区土壤酶活性研究

采用逐步多元回归和主成分分析的方法研究了德兴铜矿周边土壤中重金属和土壤酶活性的关系.结果表明:德兴铜矿周边各功能区均受到不同程度的Cu、Cd污染,Pb、Zn未超过《土壤环境质量标准》(GB 15618--1995)二级标准;各功能区土壤酶活性有显著差别,逐步回归分析表明土壤酶活性与Cu、Zn全量、生物可利用态Cu含量有显著线性关系,而与Cd、Pb无明显相关;土壤酶活性和生物可利用态Cu呈负线性关系,而与残渣态Cu有正线性关系.主成分分析显示,土壤酶信息系统的第1、第2主成分可反映酶活性总变异的96.27%,根据第1主成分对功能区酶活性的分类结果与土壤生物可利用态Cu含量的分类结果基本一致,提示土壤酶活性指标可以反映土壤生物可利用态Cu含量.     

安全验收评价的体系构建与实践探索

从完善我国安全评价工作的角度出发,提出建设安全验收评价体系的构想;在项目建设安全验收评价实践中,又提出如何进一步加大力度,认真考量建设项目的本质安全度与在安全验收评价时更加关注"人"的安全性。该项目的研究与实践是以科学技术来支撑安全生产监管成效的重要举措,对工程项目的安全验收评价提供了依据和有益参考。