Several current-use, non-PBDE brominated flame retardants are highly bioaccumulative: evidence from field determined bioaccumulation factors

With the phaseout of brominated flame retardants (BFRs) polybrominated diphenyl ethers (PBDEs), some non-PBDE BFRs have prompted to be alternatives to the discontinued PBDEs. To assess the bioaccumulation potential of these chemicals, field bioaccumulation factors (BAFs) for several non-PBDE BFRs including hexabromocyclododecanes (HBCDs), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), pentabromotoluene (PBT), pentabromoethylbenzene (PBEB), and hexabromobenzene (HBB), were determined in the aquatic species from a natural pond in an electronic waste recycling site in South China. The log BAFs ranged 2.58-6.01, 3.24-5.58, 3.44-5.98, 2.85-5.98, 3.32-6.08, 2.04-4.77, 2.72-4.09 and 3.31-5.54 for α-HBCD, β-HBCD, γ-HBCD, ∑HBCDs, BTBPE, PBT, PBEB, and HBB, respectively. The log BAF values for HBCD isomers, BTBPE, and HBB were greater than 3.7 (corresponding BAF value 5000) in most of the investigated species, demonstrating their highly bioaccumulative properties. α-, β-, and γ-HBCDs, BTBPE, and HBB appeared comparable or had even greater BAFs compared to PBDE congeners with similar K(OW), suggesting that these BFRs may have a potentially high environmental risk. The BAFs for the given BFR compound were largely variable between species, due to the species-specific feeding ecology, trophic level, and metabolic capacity for these pollutants. Positive linear relationships between log BAF and log K(OW) (r2 = 0.59, p = 0.04), and molecular weight (r2 = 0.54, p = 0.06) of non-PBDE BFRs were observed in the species with low trophic level (Chinese mysterysnail), suggesting that the chemical's physicochemical properties also played key roles in the bioaccumulation processes.     

湿法再生吸附剂制备及用于大气CO2的直接捕集

基于湿法再生吸附技术，利用强碱性季铵盐树脂材料制备了异相吸附剂薄膜，应用于大气中极低CO2的直接分离，以对抗全球变暖。通过滴定法分析吸附剂材料的电荷密度和吸附容量，利用SEM分析不同工况下制备出来的膜材料的表观结构，并对膜材料进行CO2吸附性能的测试。结果发现，热处理能够明显提高膜材料的吸附性能，还研究吸附剂制备对吸附速率，吸附量和机械强度等性能的影响，发现粒径小于43μm的树脂粉末，按60％质量分数制成的500μm厚膜材料具有较优的综合性能。     

移动床生物膜反应器预处理含酚废水

采用两级移动床生物膜反应器（MBBR）预处理高挥发酚含量的石化厂汽提净化水，考察了HRT和DO对废水中挥发酚和COD去除效果的影响。实验结果表明：在两级MBBR总HRT为10 h、MBBR中部废水DO 为1~3 mg/L的条件下， 装置连续运行处理ρ（挥发酚）=110~201 mg/L、COD=644~1 827 mg/L、BOD₅/COD=0.15~0.69的废水，两级MBBR处理后出水平均ρ（挥发酚）为17.6 mg/L，挥发酚去除率达87.9%;平均COD为745 mg/L，COD去除率为32.7%;出水BOD₅/COD平均为0.68，表明经过两级MBBR处理后，废水的可生化性有所提高，有利于废水的后续生化处理。     

Species- and tissue-specific accumulation of Dechlorane Plus in three terrestrial passerine bird species from the Pearl River Delta, South China

Little data is available on the bioaccumulation of Dechlorane Plus (DP) in terrestrial organisms. Three terrestrial passerine bird species, light-vented bulbul, long-tailed shrike, and oriental magpie-robin, were collected from rural and urban sites in the Pearl River Delta to analyze for the presence of DP and its dechlorinated products in muscle and liver tissues. The relationships between trophic level and concentration and isomeric composition of DP in birds were also investigated based on stable nitrogen isotope analysis. DP levels had a wide range from 3.9 to 930 ng g⁻¹ lipid weight (lw) in muscle and from 7.0 to 1300 ng g⁻¹ lw in liver. Anti-Cl₁₁-DP and syn-Cl₁₁-DP, two dechlorinated products of DP, were also detected in bird samples with concentrations ranged between not detected (nd)-41 and nd-7.6 ng g⁻¹ lw, respectively. DP preferentially accumulated in liver rather than in muscle for all three bird species. Birds had significantly higher concentrations of DP in urban sites than in rural sites (mean, 300 vs 73 ng g⁻¹ lw). The fractions of anti-DP (f_anti) were higher in birds collected in rural sites than in urban sites. Significant positive correlation between DP levels and δ¹⁵N values but significant negative correlation between f_anti and δ¹⁵N values were found for birds in both urban and rural sites, indicating that trophic level of birds play an important role in determining DP level and isomeric profile.     

Determination of picogram quantities of chlortoluron in soil samples by luminol–chitosan chemiluminescence system

Based on the enhancing effect of chitosan (CS) on luminol-dissolved oxygen chemiluminescence (CL) reaction, a flow injection (FI) luminol–CS CL system was established. It was found that the increase of CL intensity was proportional to the concentrations of CS ranging from 0.7 to 10.0 μmol l^?1. In the presence of chlortoluron (CTU), the CL intensity of luminol–CS system could be obviously inhibited and the decrements of CL intensity were linearly proportional to the logarithm of CTU concentrations ranging from 0.01 to 70.0 ng ml^?1, giving the limit of detection 3.0 pg ml^?1 (3σ). At a flow rate of 2.0 ml min^?1, the whole process including sampling and washing could be accomplished within 36 s, offering a sample throughput of 100 h^?1. The proposed FI–CL method was successfully applied to the determination of CTU in soil samples with recoveries ranging from 95.0 % to 105.3 % and the relative standard deviations (RSDs) of less than 4.0 %.     

低温NH_3-SCR脱硝催化剂的研究现状与进展

高效催化剂的研制与开发是低温氨气选择性催化还原(NH_3-SCR)脱硝技术的核心。从活性组分(单一氧化物型、复合氧化物型)和载体(金属氧化物、碳基材料、分子筛)两方面详细介绍了低温NH_3-SCR催化剂,总结了其研究现状,并讨论了其抗水、抗硫性能及失活原因。指出在保证催化剂具有较高活性的同时提高其抗水、抗硫性能,是低温NH_3-SCR催化剂未来研究的重点。     

The Impact of Perceptual and Situational Factors on Environmental Communication: A Study of Citizen Engagement in China

This study applied a situational approach to understanding an environmental problem: PM2.5 (its resulted haze and smog air pollution) in China. Based on a national sample of 374 citizens living in China, it tested a situational model of problem solving and extended it by adding citizens’ environmental engagement behaviour as an immediate consequence of their communicative action. Results of a structural equation modelling analysis supported all the causal links in the conceptual model. Moreover, communicative action significantly mediated the relationship between referent criterion and environmental engagement. Problem recognition, constraint recognition, and involvement recognition did not influence environmental engagement directly, but exerted their significant indirect impact via two key mediators in the model: situational motivation in problem solving and communicative action in problem solving. Theoretical and practical implications of the present study were discussed.     

Study on turbulence characteristics and sensitivity of quadrant analysis to threshold level in Lake Taihu

Environmental Science and Pollution Research - The identification of coherent structures is very important in investigating the sediment transport mechanism and controlling the eutrophication in...     

Bioremediation of oily sludge-contaminated soil by stimulating indigenous microbes

In situ bioremediation of oily sludge-contaminated soil by biostimulation of indigenous microbes through adding manure was conducted at the Shengli oilfield in northern China. After bioremediation for 360 days, total petroleum hydrocarbon (TPH) content was reduced by 58.2% in the treated plots compared with only 15.6% in the control plot. Moreover, bioremediation significantly improved the physicochemical properties of the soil in the treated plot. Soil microbial counts and community-level physiological profiling were also examined. Manure addition increased TPH degraders and polycyclic aromatic hydrocarbon (PAH) degraders in the contaminated soil by one to two orders of magnitude. The activity and biodiversity of soil microbial communities also increased markedly in the treated plot compared with that of the control. Finally, biotoxicity was used to evaluate the soils and a sharp increase in the EC50 of the soil after bioremediation was observed, indicating that bioremediation had reduced the toxicity of the soil.     

生活垃圾焚烧发电厂的环境风险评价

垃圾焚烧技术兼具环境效益和经济效益,环境风险评价的结论是该类项目选址的关键问题之一。在分析中国城市生活垃圾排放现状和生活垃圾焚烧项目环境风险的基础上,分析了二恶英风险事故的环境影响及环境防护距离的计算方法与传统卫生防护距离的差异,并以秦皇岛生活垃圾焚烧发电厂为实例进行了计算。结果表明:在不同工况下人体经呼吸每日最大摄入二恶英的量均远小于允许摄入量参考标准值,环境防护距离确定方法更为科学和人性化,有利于消除公众对此类建设项目的误解。