Monocyclic and monoaromatic naphthenic acids: synthesis and characterisation

Characterisation of the complex mixtures of carboxylic acids (naphthenic acids) occurring in crude oils and in degraded oil sands is environmentally important. Indeed some acids in waters from oil platforms are apparently hormonally active, and the oil sands acids are said to be toxic to a wide range of biota. Previous attempts to identify monocyclic and monoaromatic naphthenic acids have been hampered by the lack of authenticated synthetic reference compounds. Some studies have indicated that acids with ethanoic acid side chains are present in the naphthenic acids mixtures, so in the present study, we synthesised and characterised by mass spectrometry, a range (C_8–14) of monoaromatic and monocyclic ethanoic acids. Using 2-D comprehensive gas chromatography–mass spectrometry, we then compared the retention times and mass spectra of the synthetic acids with those of a commercial naphthenic acids mixture. Some alicyclic and numerous aromatic acids were successfully identified.     

Spatial distribution,pollution characteristics,and health risks of antibiotic resistance genes in China: a review

Environmental Chemistry Letters - With the extensive production and use of antibiotics for medicinal and veterinary purposes, antibiotics and genes that code for antibiotic resistance are now...     

The non-target organism Caenorhabditis elegans withstands the impact of sulfamethoxazole

The widespread usage of antibiotics in agriculture leads to releases into the environment, but there is insufficient knowledge of the side-effects on non-target organisms. Therefore, we investigated the effects of the sulfonamide-antibiotic sulfamethoxazole (SMX) on Caenorhabditis elegans at phenotypic, biochemical and molecular biological levels. Multiple endpoints, including life history traits, thermal stress resistance and lipid peroxidation, as well as gene expression profiles, were determined after exposure of the nematodes to SMX. In contrast to expectations, SMX prolonged the lifespan and increased both the body size and pharynx pumping rate. On the other hand, SMX delayed reproductive timing and caused lipid peroxidation. The total number of offspring and thermal stress resistance were unaffected. The up-regulation of hsp-16.1 indicated stress in general and the increased lipid peroxidation oxidative stress in particular. This oxidative stress indicated that mitohormesis was the likely cause of the longevity and that enhanced pumping frequency was probably the reason for the increased growth. The sole adverse effect was delayed initial reproduction. This delay, however, can be crucial for r-strategists, such as the bacterivorous model animal used, in sustaining their populations in the environment in the presence of predators. Bacterivorous animals, in turn, are essential to maintaining nutrient recycling via the microbial loop.     

Comparing and evaluating the nationally determined contributions of the top six emitters under the Paris Agreement goals

ABSTRACT

Comparing and evaluating the Nationally Determined Contribution (NDC) is an important element in global stocktake in the post-Paris climate negotiations, aimed at closing the emissions gap with the Paris Agreement goals. To date, however, there has still been no explicit guideline or method. By applying emissions allowance allocated by 16 schemes as benchmarks, this paper tries to compare and evaluate the NDCs of the top six emitters, which jointly account for about 70% of the world’s CO₂ emissions. Results show that the four developed countries’ NDCs lack ambition with respect to most allocations under 2°C and all under 1.5°C, indicating they need to substantially ratchet up their NDCs and lead elevating mitigation. Evaluating cumulative emissions is more likely to clarify the ambition and fairness of China’s NDC. If considering cumulative emissions, China’s NDC is aligned with the median of cumulative allowances under 2°C and within the 1.5°C range. The Paris Agreement invited the Parties to communicate the mid-century low emissions strategies. This paper also tries to explore the mid-century mitigation in the perspective of allocations, which might provide decision-makers with some useful information when envisaging the post-NDC mitigation.     

Risk evaluation of natural disasters based on connection function

There are many uncertain factors,such as stochastic,fuzzy and gray information in the risk analysis on natural hazard.The set pair analysis(SPA)deals effectively with the various uncertain factors contributing to evaluation of the risk level of natural disasters.The evaluation indicators and standards of natural disasters risk are analyzed by identity-discrepancycontrary(IDC).The result,the connection numbers,still has uncertainty information.Thus,yielding the risk evaluation model of natural disasters based on connection function,which construct a set pair relation between the indicators of connection numbers and comprehensive evaluation standards,and describe uncertainty of the connection numbers by using connection function.The study showed that the proposed model takes into account only the uncertainty of risk evaluation indicator identification on natural disasters,also the uncertainty of result connection numbers.This approach gives full consideration to the uncertainty of systematic evaluation process along with the actual meaning of comprehensive evaluation functions.Therefore,this means it is able to reduce the uncertainty of final evaluation results and improve the accuracy and reasonability of evaluation results.This model is capable of reflecting actual situation of the risk evaluation on natural disaster affected by various uncertain factors and has a promotional value in the natural disaster risk assessment.     

Assessing the Eutrophication of Shengzhong Reservoir Based on Grey Clustering Method

Abstract

Reservoir water environment is a grey system. The grey clustering method is applied to assessing the reservoir water environment to establish a relatively complete model suitable for the reservoir eutrophication evaluation and appropriately evaluate the quality of reservoir water, providing evidence for reservoir management. According to China’s lakes and reservoir eutrophication criteria and the characteristics of China’s eutrophication, as well as certain evaluation indices, the degree of eutrophication is classified into six categories with the utilization of grey classified whitening weight function to represent the boundaries of classification, to determine the clustering weight and clustering coefficient of each index in grey classifications, and the classification of each clustering object. The comprehensive evaluation of reservoir eutrophication is established on such a foundation, with Sichuan Shengzhong Reservoir as the survey object and the analysis of the data attained by several typical monitoring points there in 2006. It is found that eutrophication of Tiebian Power Generation Station, Guoyuanchang and Dashiqiao Bridge is the heaviest, Tielusi and Qinggangya the second, and Lijiaba the least. The eutrophication of this reservoir is closely relevant to the irrational exploitation in its surrounding areas, especially to the aggravation of the non-point source pollution and the increase of net-culture fishing. Therefore, it is feasible to use grey clustering in environment quality evaluation, and the point lies in the correct division of grey whitening function     

The Concept and Theoretical Implications of Carbon Emissions Rights Based on Individual Equity

Abstract

Climate change has become a hot topic in international environmental negotiations. For post-Kyoto international climate regime negotiations, many countries have proposed a variety of frameworks to share the emission reduction responsibilities and allocate carbon emission rights, and have tried to quantify the emission reduction obligations of all countries based on the perspectives of international equity and individual equity. In this paper, the authors have distinguished the concepts of carbon emissions rights based on these two perspectives respectively, have analyzed the relationship between carbon emissions per capita and economic development, and have calculated and compared the proportion of cumulative emissions per capita of different countries in history and future, and then authors conclude that emission reduction obligations should be allocated based on each country’s conditions, including historical emissions, development stage, and future demands. Developed countries should take the initiative to significantly reduce their emissions because they have already accomplished their industrialization process. However, developing countries are still in the process of industrialization, which requires more emission rights to meet their development needs. For China, the concept of carbon emissions based on individual equity can be used as a theoretical tool for the allocating the international carbon emissions rights.     

含油污泥物化法处理研究进展

含油污泥是石油开采及加工过程中产生的含油量高、脱水难、水溶性小的固体废物。文章主要介绍了国内物化技术处理含油污泥研究的现状及进展,包括洗脱、萃取、调质分离、热洗、调剖等。对这些方法进行了评价和比较,并对今后的研究方向提出建议,需要在微波、超声波和调剖剂上作进一步研究。     

新型L沸石在FCC汽油加氢脱硫催化剂中的应用研究

采用等体积浸渍法,制备了一系列含有相同含量活性组分(MoO3、CoO和NiO)不同USL沸石含量的加氢脱硫催化剂。通过X-射线衍射(XRD)、氮气吸附脱附、吡啶红外(Py-FTIR)和氨气程序升温脱附(NH3-TPD)等分析方法对样品进行了表征。结果表明:与Cat.0(参比剂,仅以γ-Al2O3为载体)相比,添加USL沸石催化剂所得加氢油的烯烃含量、芳烃含量和研究法辛烷值(RON)均增加;仅当催化剂载体中USL沸石加量在0~40m%之间变化时,加氢油的异构烷烃含量呈上升趋势;而当载体中USL沸石添加量在0~20m%之间变化时,催化剂的脱硫率有所升高。综合对比,当载体中USL沸石添加量约为40m%,催化剂具有最佳的综合性能指标,脱硫率达90%,RON损失仅为1.5左右。     

Synthesis and Characterization of Bio-Based Amorphous Polyamide From Dimethyl furan-2,5-dicarboxylate

Journal of Polymers and the Environment - In this research, bio-based polyamide (bio-PA) was synthesized from dimethyl furan-2,5-dicarboxylate and 1,3-cyclohexanedimethanamine by melt...