A field study of the relationship between sulfide-bound metals and bioaccumulation by Limnodrilus sp. in a heavily polluted river

Acid volatile sulfide (AVS) has been regarded as an important factor controlling metal bioavailability in anoxic sediments, but its effect on metal accumulation under natural conditions is poorly understood. Here, a field study of the influence of AVS on metal accumulation by Limnodrilus sp. in a heavily polluted river is provided. Most of the study area was subject to anaerobic and strongly reducing conditions, and the concentration of trace metals in surface sediments was high, as were the concentration of AVS and simultaneously extracted metals (SEM; average AVS?=?20.3 μmol g^?1, average ∑SEM₅?=?9.42 μmol g^?1; ∑SEM₅ refers to the sum of SEM_Cd, SEM_Cu, SEM_Pb, SEM_Ni, and SEM_Zn). Only a few species and small quantities of benthic invertebrates were found, and Limnodrilus sp. was dominant. There was no correlation between trace metal accumulation and (SEM-AVS), and in stations where (SEM-AVS) <0, the absolute value of bioaccumulation was high (average ∑BIO₅?=?4.07 μmol g^?1; ∑BIO₅ refers to the sum of BIO_Cd, BIO_Cu, BIO_Pb, BIO_Ni, and BIO_Zn), indicating that there was no relationship between (SEM–AVS) and metal accumulation in Limnodrilus sp. This was likely because Limnodrilus sp. ingest sediment particles as their main food source, so pore water metals play a minor role in their bioaccumulation (BIO) of materials. However, ∑BIO₅ was significantly correlated with ∑SEM₅ (r?=?0.795, p?<?0.01), revealing that the large number of sulfide-bound metals (SEM) in sediments may play an important role in metal accumulation in Limnodrilus sp., which can assimilate sulfide-associated metals by the help of the digestive fluids in the digestive systems.     

Grey optimization Verhulst model and its application in forecasting coal-related CO2 emissions

Environmental Science and Pollution Research - Energy saving and emission reduction are the most concerned issues in the world. Objective and accurate prediction of carbon emissions can provide...     

Suggestion on further strengthening ultra-low emission standards for PM emission from coal-fired power plants in China

China has established the largest clean coal-fired power generation system in the world by accomplishing the technological transformation of coal-fired power plants(CFPPs) to achieve ultra-low emission. The potential for further particulate matter(PM) emission reduction to achieve near-zero emission for CFPPs has become a hotspot issue. In this study,PM emission from some ultra-low emission CFPPs adopting advanced air pollutant control technologies in China was reviewed. The results revealed tha...     

Key emergency response technologies for abrupt air pollution accidents in China

Abrupt air pollution accidents can endanger people’s health and destroy the local ecological environment. The appropriate emergency response can minimize the harmful effects of accidents and protect people’s lives and property. This paper provides an overview of the key emergency response technologies for abrupt air pollution accidents around the globe with emphasis on the major achievements that China has obtained in recent years.With decades of effort, China has made significant progress in em...     

双子表面活性剂CG_(12-3-12)、鼠李糖脂与TX-100对多环芳烃增溶作用的比较研究

对新季铵盐型Gemini阳离子表面活性剂CG12-3-12、生物表面活性剂鼠李糖脂Rhamnolipid、普通非离子表面活性剂TX-100以及它们的混合体系对多环芳烃菲和芘的增溶效果进行了比较研究.通过计算与比较临界胶束浓度(CMC)、摩尔增溶率(MSR)和增溶的标准自由能ΔG0s,评价了3种不同类型表面活性剂及它们的混合体系对菲和芘的增溶能力.3种表面活性剂对菲和芘的增溶性大小顺序为:CG12-3-12RhamnolipidTX-100.TX-100/CG12-3-12与TX-100/Rhamnolipid混合表面活性剂都较相对应的单一表面活性剂有更好的增溶能力,在降低表面张力效率方面都能够产生协同效应.但是两种混合溶液都不符合理想溶液的性质.TX-100/CG12-3-12系统的CMCexp相对于CMCmi有更大的负偏差.由两混合体系的吉布斯自由能ΔG0m可以看出,TX-100与鼠李糖脂比与CG12-3-12更容易形成混合胶束.TX-100/CG12-3-12与TX-100/Rhamnolipid表现出协同作用.TX-100/Rhamnolipid混合体系对菲和芘的增溶能力的提高大于TX-100/CG12-3-12混合体系.本实验研究结果可为疏水性有机物污染环境修复效果的强化提供科学依据.     

基于水质模型的污染监控预警和应急管理研究

地表水环境的治理和改善受到社会、经济、环境等多方面因素的共同影响,如何合情、合理地制定地表水污染防治政策、规划,在复杂的水环境污染突发事件中及时掌握事态的发展和正确的处理处置方法是我国各级环境保护管理部门面临的一大难题。本论文以建立水质污染扩散模型为基础,结合我国地表水环境管理现状提出了一套地表水污染监控预警和应急管理体系,旨在建立废水污染源与地表水环境质量的内在联系,用科学的方法为地表水污染防治管理工作提供技术支撑。     

辽河源头区畜禽养殖粪便处理处理现状及对策初探

本文以畜禽养殖较为集中、污染问题较为突出的辽河源头区为研究区域,通过流域内畜禽污染物排放方式,污染物排放总量,总结流域内畜禽养殖污染特点,在次基础上提出切实可行的畜禽污染防治对策,为相关政策的制定提供依据。     

Environmental significance of biogenic elements in surface sediments of the Changjiang Estuary and its adjacent areas

Biogenic elements and six phosphorus(P) fractions in surface sediments from the Changjiang Estuary and adjacent waters were determined to investigate the governing factors of these elements, and further to discuss their potential uses as paleo-environment proxies and risks of P release from sediment. Total organic carbon(TOC) and leachable organic P(Lea-OP) showed high concentrations in the estuary, Zhejiang coast and ofshore upwelling area. They came from both the Changjiang River and marine biological input.Biogenic silicon(BSi) exhibited a high concentration band between 123 and 124°E. BSi mainly came from diatom production and its concentration in the inshore area was diluted by river sediment. Total nitrogen(TN) was primarily of marine biogenic origin. Seaward decreasing trends of Fe-bound P and Al-bound P revealed their terrestrial origins. Influenced by old Huanghe sediment delivered by the Jiangsu coastal current, the maximum concentration of detrital P(Det-P) was observed in the area north of the estuary. Similar high concentrations of carbonate fluorapatite(CFA-P) and CaCO3 in the southern study area suggested marine calcium-organism sources of CFA-P. TOC, TN and non-apatite P were enriched in fine sediment, and Det-P partially exhibited coarse-grain enrichment, but BSi had no correlation with sediment grain size. Diferent sources and governing factors made biogenic elements and P species have distinct potential uses in indicating environmental conditions. Transferable P accounted for 14%-46% of total P. In an aerobic environment,there was low risk of P release from sediment, attributed to excess Fe oxides in sediments.     

Land Use and Climate Variability Amplify Carbon,Nutrient, and Contaminant Pulses: A Review with Management Implications

Nonpoint source pollution from agriculture and urbanization is increasing globally at the same time climate extremes have increased in frequency and intensity. We review >200 studies of hydrologic and gaseous fluxes and show how the interaction between land use and climate variability alters magnitude and frequency of carbon, nutrient, and greenhouse gas pulses in watersheds. Agricultural and urban watersheds respond similarly to climate variability due to headwater alteration and loss of ecosystem services to buffer runoff and temperature changes. Organic carbon concentrations/exports increase and organic carbon quality changes with runoff. Nitrogen and phosphorus exports increase during floods (sometimes by an order of magnitude) and decrease during droughts. Relationships between annual runoff and nitrogen and phosphorus exports differ across land use. CH₄ and N₂O pulses in riparian zones/floodplains predominantly increase with: flooding, warming, low oxygen, nutrient enrichment, and organic carbon. CH₄, N₂O, and CO₂ pulses in streams/rivers increase due to similar factors but effects of floods are less known compared to base flow/droughts. Emerging questions include: (1) What factors influence lag times of contaminant pulses in response to extreme events? (2) What drives resistance/resilience to hydrologic and gaseous pulses? We conclude with eight recommendations for managing watershed pulses in response to interactive effects of land use and climate change.