城市老工业区整体搬迁规划环评的关键问题

城市老工业区搬迁规划环评具有层次多、涉及面广的特点。评价首先要分清规划的层次,理清3个层面规划内容,分析所涉及到的主要环境问题,按照规划、区域和项目环评3个层次分别开展评价工作。在规划层面上应重点解决好产业发展政策的符合性和选址合理性论证;区域环评层面重点进行区域布局、结构、基础设施的支撑能力和环境的承载力评价;项目层次重点弄清污染特征、污染源和污染控制措施,评价其环境影响。     

滤筒法测定水中悬浮物的实践

采用重量法用滤筒替代滤膜进行测定水中悬浮物的比对实验,实验结果表明:滤筒测定水中悬浮物比滤膜测定水中悬浮物更具有易恒重、测定误差小、准确度高、快速、简便、成本低等优点,适合水质监测应用。     

微酸多年卧孔菌产漆酶条件优化及其在染料脱色中的应用

微酸多年卧孔菌(Perenniporia subacida)产漆酶能力对生物漂白等研究具有重要意义.通过单因子和正交试验确定了微酸多年卧孔菌(菌株号:Dai 8224)的最适产酶条件:麦芽糖20 g/L,酵母浸粉5 g/L,pH 5.4,Cu2+2.0 mmol/L,培养温度24℃,转速160 r/min,接种量1.5%(V/V),此时酶活最高可达1.945 U/mL.单独使用微酸多年卧孔菌漆酶粗酶液对染料具有很好的脱色效果.该菌株对于50 mg/L杂环类染料中性红的脱色率可达98.3%,对偶氮染料刚果红的脱色率次之,为91.57%,对亚甲基蓝和铬天青的脱色率也都在80%以上.此外,其催化中性红脱色的最佳底物浓度为60 mg/L,脱色率达到99.42%,其中,生物降解作用占55.92%,菌体吸附作用占43.5%.结果表明该菌对多种染料脱色具有较大的应用潜力.图4表3参31     

Sorption of phthalate acid esters on black carbon from different sources

Black carbon (BC) is known as a strong sorbent for the sorption of planar hydrophobic organic compounds (HOCs), but there is very little information about the sorption of nonplanar HOCs on BC. In this study, the sorption of di-(2-ethyl-hexyl) phthalate (DEHP), one kind of nonplanar phthalate acid ester (PAE), by environmental BC collected from river sediments and pure BC (char-wood, char-stalk and soot-ash) was investigated. Strong and nonlinear sorption was observed for the sorption of DEHP on both pure BC and environmental BC with the Freundlich exponent ranging from 0.55 to 0.75 except for soot-ash, and the measured K(BC) (BC-water partition coefficient) of DEHP was about one order of magnitude higher than its organic carbon-water partition coefficient. There was a significant difference in sorption capacity among the environmental and pure BC. The presence of di-methyl phthalate (DMP) could significantly decrease the sorption of DEHP on BC, especially for environmental BC. In addition, the contribution of BC to the total sorption of DEHP on original river sediments was more than 50% when the equilibrium concentration of DEHP was less than 10 μg L(-1). This study indicated that ortho-substituted nonplanar PAEs could also be strongly sorbed by BC, and the difference in sorption among the BC samples revealed that it is important to take the source of BC into account when assessing its effects on the fate of HOCs in aquatic environment.     

Intraspecific variation in cadmium tolerance and accumulation of a high-biomass tropical tree Averrhoa carambola L.: implication for phytoextraction

Averrhoa carambola L., a high-biomass tropical tree, has recently been shown to be a strong accumulator of cadmium (Cd) and has great potential for Cd phytoextraction. In the present study, field studies and a controlled-environment experiment were combined to establish the extent of variation in Cd tolerance and accumulation at the cultivar level using 14 to 19 cultivars of A. carambola. The results indicated that all cultivars tested could accumulate Cd at high but different levels, and that Cd tolerance also varied greatly between these cultivars. It is confirmed that the high Cd tolerance and accumulation capacity are species-level and constitutional traits in A. carambola. However, no correlation was detected between tolerance index and accumulation of Cd in different cultivars, suggesting that the two traits are independent in this woody Cd accumulator. More importantly, cultivar Wuchuan Sweet (WCT) was shown to have the highest Cd-extraction potential; it yielded a high shoot biomass of 30 t ha(-1) in 230 d, and extracted 330 g ha(-1) Cd in the aerial tissues grown in Cd-contaminated field soil, which accounted for 12.8% of the total soil Cd in the top 20 cm of the soil profile.     

Impact of meteorological condition changes on air quality and particulate chemical composition during the COVID-19 lockdown

Stringent quarantine measures during the Coronavirus Disease 2019 (COVID-19) lockdown period (January 23, 2020 to March 15, 2020) have resulted in a distinct decrease in anthropogenic source emissions in North China Plain compared to the paralleled period of 2019. Particularly, 22.7% decrease in NO₂ and 3.0% increase of O₃ was observed in Tianjin, nonlinear relationship between O₃ generation and NO₂ implied that synergetic control of NO_x and VOCs is needed. Deteriorating meteorological condition during the COVID-19 lockdown obscured the actual PM_2.5 reduction. Fireworks transport in 2020 Spring Festival (SF) triggered regional haze pollution. PM_2.5 during the COVID-19 lockdown only reduced by 5.6% in Tianjin. Here we used the dispersion coefficient to normalize the measured PM_2.5 (DN-PM_2.5), aiming to eliminate the adverse meteorological impact and roughly estimate the actual PM_2.5 reduction, which reduced by 17.7% during the COVID-19 lockdown. In terms of PM_2.5 chemical composition, significant NO₃^? increase was observed during the COVID-19 lockdown. However, as a tracer of atmospheric oxidation capacity, odd oxygen (O_x = NO₂ + O₃) was observed to reduce during the COVID-19 lockdown, whereas relative humidity (RH), specific humidity and aerosol liquid water content (ALWC) were observed with noticeable enhancement. Nitrogen oxidation rate (NOR) was observed to increase at higher specific humidity and ALWC, especially in the haze episode occurred during 2020SF, high air humidity and obvious nitrate generation was observed. Anomalously enhanced air humidity may response for the nitrate increase during the COVID-19 lockdown period.     

Development of Hybrid Film Based on Carboxymethyl Chitosan-Gum Arabic Incorporated Citric Acid and Polyphenols from Cinnamomum camphora Seeds for Active Food Packaging

Journal of Polymers and the Environment - In this study, carboxymethyl chitosan with gum Arabic (CG) based novel functional films containing Cinnamomum camphora seeds extract (CCSE) at varying...     

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.     

Highly efficient photocatalytic oxidation of antibiotic ciprofloxacin using TiO2@g-C3N4@biochar composite

Environmental Science and Pollution Research - In this present study, a novel indirect Z-scheme TiO2@g-C3N4@biochar (TiO2@g-C3N4@BC) composite photocatalyst was successfully fabricated and...     

Investigation of indole biodegradation by Cupriavidus sp. strain IDO with emphases on downstream biotransformation and indigo production

Environmental Science and Pollution Research - Indole, as a typical N-heterocyclic aromatic pollutant, poses risks to living things; however, indole-biotransformation mechanisms remain...