Adsorption of pharmaceuticals to microporous activated carbon treated with potassium hydroxide, carbon dioxide, and steam

Adsorption of sulfapyridine, tetracycline, and tylosin to a commercial microporous activated carbon (AC) and its potassium hydroxide (KOH)-, CO-, and steam-treated counterparts (prepared by heating at 850°C) was studied to explore efficient adsorbents for the removal of selected pharmaceuticals from water. Phenol and nitrobenzene were included as additional adsorbates, and nonporous graphite was included as a model adsorbent. The activation treatments markedly increased the specific surface area and enlarged the pore sizes of the mesopores of AC (with the strongest effects shown on the KOH-treated AC). Adsorption of large-size tetracycline and tylosin was greatly enhanced, especially for the KOH-treated AC (more than one order of magnitude), probably due to the alleviated size-exclusion effect. However, the treatments had little effect on adsorption of low-size phenol and nitrobenzene due to the predominance of micropore-filling effect in adsorption and the nearly unaffected content of small micropores causative to such effect. These hypothesized mechanisms on pore-size dependent adsorption were further tested by comparing surface area-normalized adsorption data and adsorbent pore size distributions with and without the presence of adsorbed antibiotics. The findings indicate that efficient adsorption of bulky pharmaceuticals to AC can be achieved by enlarging the adsorbent pore size through suitable activation treatments.     

水库水质安全保障对策研究——以长潭水库为例

水库的供水功能日渐重要,水库水质安全已经成为保障社会稳定和经济发展的基础。水库环境污染问题不断加剧,保障水库水质安全日趋紧迫。水库水质安全保障需从外源污染控制、内源污染控制、水库生态系统恢复和突发事故应急等多方面着手。本文结合长潭水库情况,全面分析水库水质安全的保障对策。     

Synthesis of a highly recoverable 3D MnO2/rGO hybrid aerogel for efficient adsorptive separation of pharmaceutical residue

Water contamination by non-steroidal anti-inflammatory drugs, such as acetaminophen, is an emerging ecological concern. In this study, a new three-dimensional manganese dioxide-engrafted reduced graphene oxide (3D MnO₂/rGO) hybrid aerogel was developed for acetaminophen sequestration. The synthesis involved firstly the self-assembly of GO aerogel, followed by thermal reduction and in-situ MnO₂ growth by redox-reaction. The aerogel demonstrated interlinked planes with smooth surfaces deposited with MnO₂ nanospheres and pores of 138.4 – 235.3 µm width. The influences of adsorbent dosage, initial pH, acetaminophen concentration, temperature and contact time were investigated. It was determined that the adsorption of acetaminophen occurred on uniform sorption sites in the aerogel, as suggested by the best fit of data to the Langmuir isotherm, yielding a maximum adsorption capacity of 252.87 mg/g. This highest adsorption performance of the 3D MnO₂/rGO aerogel was attained at a dosage of 0.6 g/L, initial pH of 6.2 and temperature of 40°C. The process kinetics were in-line with the pseudo-first-order and pseudo-second-order kinetics at 10 and 20 – 500 mg/L concentrations, respectively. Thermodynamic assay showed the spontaneity and endothermicity features of the 3D MnO₂/rGO-acetaminophen system. The acetaminophen adsorption mechanisms were mainly hydrogen bonding and pore entrapment. Moreover, the as-synthesised aerogel was effectively regenerated using acetone and re-utilised in four adsorption-desorption cycles. Overall, the results highly recommend the implementation of the 3D MnO₂/rGO hybrid aerogel for purification of wastewater polluted by acetaminophen residue.     

光纤光栅传感器及其应用

综述了几种典型光纤光栅传感器及在传感领域的应用。首先介绍了光纤光栅传感的基本原理,然后对布拉格光栅、长周期光栅、倾斜光栅和啁啾光栅的结构、光学特性进行了说明。最后阐述了光纤光栅传感器在温度传感、结构健康监测、腐蚀研究等方面的应用,以及在应用上的不足和今后的发展方向。     

Effects of high dose copper on plant growth and mineral nutrient (Zn,Fe, Mg,K, Ca) uptake in spinach

Loessal soil is one of the main cultivated soils in northwest China. Part of its distribution area was irrigated with industrial wastewater in past three decades. This caused heavy metal contamination in the soil. It had induced toxicity on crops and also threatened local human health for now. Based on a field plot experiment, effects of different Cu concentrations (from 45 to 2000 mg kg^?1) in loessal soil on spinach plant growth and uptake of mineral nutrients (Zn, Fe, Mg, K, and Ca) by spinach were investigated. The Cu addition increased available concentrations of mineral nutrients in loessal soil and concentrations of Cu, Zn, Mg, and Ca in roots. The translocation of mineral nutrients from roots to leaves was inhibited under Cu addition, inducing their decrease in leaves. The EC₁₀ and EC₅₀ of soil Cu in relative dry weights of leaves were 240.33 mg kg^?1 and 1205.04 mg kg^?1, respectively. The PLS-PM analysis showed that available concentrations of nutrients in soil were only affected by Cu in soil positively, nutrients in roots were mainly affected by Cu in soil and Cu in leaves positively, nutrients in leaves were mainly affected by Cu in roots negatively, translocation of nutrients in spinach and plant growth were principally affected by Cu in leaves negatively, and the total effect of Cu in leaves on nutrients in roots and leaves, translocation of nutrients in spinach, and plant growth was the highest. Our results indicated that the phytotoxicity of Cu including spinach growth inhibition and mineral disorder in spinach was mainly affected by the Cu concentrations in leaves.

     

Evaluation of toxic effects induced by arsenic trioxide or/and antimony on autophagy and apoptosis in testis of adult mice

Environmental Science and Pollution Research - Arsenic trioxide (ATO) and antimony (Sb) are well-known ubiquitous environmental contaminants and cause unpromising male reproductive effects in...     

Can corporate environmental responsibility improve environmental performance? An inter-temporal analysis of Chinese chemical companies

The empirical research on the relationship between corporate environmental responsibility and environmental performance remains in the one-way positive impact and lacks the research on nonlinear relationship between them. Based on the stakeholder theory, this paper selects A-share chemical–listed companies in China from 2006 to 2017 as the research samples and uses generalized method of moments (GMM) model to investigate the impact mechanism between corporate environmental responsibility and environmental performance. The results showed that corporate environmental responsibility positively impacted on environmental performance; however, the impact was not significant. The corporate environmental performance positively and significantly impacted on environmental responsibility. Moreover, results reported that industry competition played a positive regulatory role in corporate environmental responsibility affecting environmental performance and has played a positive role in corporate environmental impact on environmental responsibility. A nonlinear relationship (inverted “U” shape) between environmental responsibility and environmental performance was found. The study results stress to establish a fair and perfect market competition mechanism to improve the environmental performance of chemical industries in China.

     

Occurrence and risk evaluation of organophosphorus pesticides in typical water bodies of Beijing,China

Environmental Science and Pollution Research - Abstract Human activities, particularly in large cities, can lead to pollution caused by micropollutants such as pesticides in water bodies, which...     

Application of sewage sludge and intermittent aeration strategy to the bioremediation of DDT-and HCH-contaminated soil

Adding organic amendments to stimulate the biodegradation of pesticides is a subject of ongoing interest. The effect of sewage sludge on the bioremediation of dichlorodiphenyltrichloroethane（DDT） and hexachlorocyclohexane（HCH） contaminated soil was investigated in bench scale experiments,and intermittent aeration strategy was also used in this study to form an anaerobic–aerobic cycle. Bioremediation of DDT and HCH was enhanced with the addition of sewage sludge and the intermittent aeration. The removal rates of HCH and DDT were raised by 16.8%–80.8% in 10 days. Sewage sludge increased the organic carbon content from 6.2 to218 g/kg,and it could also introduce efficient degradation microbes to soil,including Pseudomonas sp.,Bacillus sp. and Sphingomonas sp. The unaerated phase enhanced the anaerobic dechlorination of DDT and HCH,and anaerobic removal rates of β-HCH,o,p′-DDT and p,p′-DDT accounted for more than 50% of the total removal rates,but the content of α-HCH declined more in the aerobic phase.     

城市生态红线体系构建及其与管理制度衔接的研究

生态红线对构建科学合理的城镇化格局,保障国家区域生态安全具有重要意义。本文重点解析了生态红线的六大内涵与特征,基于结构的敏感性、过程的脆弱性、功能的重要性,研究提出包括五大领域、四大分区的生态红线体系框架。生态红线只有实现真正的"落地",并配套以完善的管控措施,才能真正实现生态红线维护城市空间格局底线的目的。生态红线可与现有的城市环境管理制度、手段等相结合,为城市环境的精细化、系统化管理提供平台。