环境监测实验室方法确认过程中常见问题探讨

根据实验室资质认定对于方法确认的要求,结合环境监测实验室的特点,提出了新项目方法确认的具体步骤,并分析了其中存在的常见问题。指出在方法确认过程中,应严格按照标准方法和监测技术规范进行全过程试验,尤其不能忽视采样现场实验、空白实验和检出限的测定。建议在精密度与准确度检验过程中,使用高、中、低不同浓度的有证标准样品,实际样品加标回收,比对试验（方法比对、人员比对、实验室间比对）,增加分析次数等多种手段,确保新项目开展的可靠性。     

Spatial and seasonal distribution of nitrogen in marsh soils of a typical floodplain wetland in Northeast China

Horizontal and profile distributions of nitrogen in marsh soils in different seasons were studied in a typical site within the Erbaifangzi wetland in Northeast China. Results showed that there was higher spatial heterogeneity for nitrate nitrogen (NO₃^--_{3}^{-}-N) and ammonium nitrogen (NH₄⁺_{4}^{+}–N), as well as available nitrogen (AN), in surface soils in July compared to that in September. Relative to July, the mean nitrogen contents in surface soils were slightly higher in September; however, in November, soils contained significantly lower NO₃^--_{3}^{-}-N and NH₄⁺_{4}^{+}–N, higher AN, organic nitrogen (Org-N), and total nitrogen (TN). Except for mineral nitrogen, no significant differences were observed between Org-N and TN contents in September and November. Nitrogen contents generally declined exponentially with depth along soil profiles in three sampling dates (July, September, and November), except for a significant accumulation peak of NO₃^--_{3}^{-}-N at the 20–30 cm depth in September. However, NH₄⁺_{4}^{+}–N contents showed a vertical alternation of “increasing and decreasing” in both July and September, while nearly kept constant with depth in November. The depth ranking of nitrogen showed the shallowest distribution for AN, followed by Org-N and TN, while deeper distributions for NO₃^--_{3}^{-}-N and NH₄⁺_{4}^{+}–N. TN, Org-N, and AN were significantly correlated with soil organic matter and total phosphorus. Soil pH values were significantly correlated with TN and AN contents in surface soils. Clay contents showed significant correlations with nitrogen contents except for NO₃^--_{3}^{-}-N in surface soils and NH₄⁺_{4}^{+}–N in profile soils. However, soil moisture was not significantly correlated with nitrogen contents among all soil samples.     

A mini review of fluoride-induced apoptotic pathways

Fluorine or fluoride can have toxic effects on bone tissue and soft tissue at high concentrations. These negative effects include but not limited to cytotoxicity, immunotoxicity, blood toxicity, and oxidative damage. Apoptosis plays an important role in fluoride-induced toxicity of kidney, liver, spleen, thymus, bursa of Fabricius, cecal tonsil, and cultured cells. Here, apoptosis activated by high level of fluoride has been systematically reviewed, focusing on three pathways: mitochondrion-mediated, endoplasmic reticulum (ER) stress-mediated, and death receptor-mediated pathways. However, very limited reports are focused on the death receptor-mediated apoptosis pathways in the fluoride-induced apoptosis. Therefore, understanding and discovery of more pathways and molecular mechanisms of fluoride-induced apoptosis may contribute to designing measures for preventing fluoride toxicity.     

Nutrients Availability Shapes Fungal Community Composition and Diversity in the Rare Earth Mine Tailings of Southern Jiangxi,China

Russian Journal of Ecology - The present study characterized the nutrients availability of three rare earth tailings deserted in different time stages in Southern Jiangxi of China, and revealed the...     

分子筛生产废水中悬浮物的絮凝与回用

对分子筛生产废水进行了絮凝沉降分离试验，确定了絮凝剂、助凝剂及絮凝敢分离条件。试验结果表明，絮凝沉降所得到的絮凝物料的化学组成、结构、性能与絮凝前原废水中的悬浮物基本一致，可返回原生产工序中使用。     

Are we planning for sustainable disaster recovery? Evaluating recovery plans after the Wenchuan earthquake

This article examines local recovery plans that were created in response to the Wenchuan earthquake and then suggests ways that planners can better apply the concept of sustainability to the recovery process. We utilize a plan evaluation protocol to analyze 16 recovery plans in counties and towns that were severely affected by the earthquake. We also conducted semi-structured interviews with public officials and planners, with the qualitative data gleaned from these interviews being used to supplement the plan quality assessment. The results reveal that local recovery plans do not appear to have incorporated sufficiently the concepts of sustainability. We conclude the paper with the following recommendations: emphasizing sustainability as a policy priority during vision and goal development; developing solid databases and planning techniques; designing a diversified set of regulatory- and incentive-based policy tools suitable for local governments; enhancing social and institutional learning; and further integrating multi-level and interagency governmental units.     

Characteristics of PM<Subscript>2.5</Subscript>, CO<Subscript>2</Subscript> and particle-number concentration in mass transit railway carriages in Hong Kong

Fine particulate matter (PM_2.5) levels, carbon dioxide (CO₂) levels and particle-number concentrations (PNC) were monitored in train carriages on seven routes of the mass transit railway in Hong Kong between March and May 2014, using real-time monitoring instruments. The 8-h average PM_2.5 levels in carriages on the seven routes ranged from 24.1 to 49.8 µg/m³, higher than levels in Finland and similar to those in New York, and in most cases exceeding the standard set by the World Health Organisation (25 µg/m³). The CO₂ concentration ranged from 714 to 1801 ppm on four of the routes, generally exceeding indoor air quality guidelines (1000 ppm over 8 h) and reaching levels as high as those in Beijing. PNC ranged from 1506 to 11,570 particles/cm³, lower than readings in Sydney and higher than readings in Taipei. Correlation analysis indicated that the number of passengers in a given carriage did not affect the PM_2.5 concentration or PNC in the carriage. However, a significant positive correlation (p < 0.001, R ² = 0.834) was observed between passenger numbers and CO₂ levels, with each passenger contributing approximately 7.7–9.8 ppm of CO₂. The real-time measurements of PM_2.5 and PNC varied considerably, rising when carriage doors opened on arrival at a station and when passengers inside the carriage were more active. This suggests that air pollutants outside the train and passenger movements may contribute to PM_2.5 levels and PNC. Assessment of the risk associated with PM_2.5 exposure revealed that children are most severely affected by PM_2.5 pollution, followed in order by juveniles, adults and the elderly. In addition, females were found to be more vulnerable to PM_2.5 pollution than males (p < 0.001), and different subway lines were associated with different levels of risk.     

Estimation of building-related construction and demolition waste in Shanghai

One methodology is proposed to estimate the quantification and composition of building-related construction and demolition (C&D) waste in a fast developing region like Shanghai, PR China. The varieties of structure types and building waste intensities due to the requirement of progressive building design and structure codes in different decades are considered in this regional C&D waste estimation study. It is concluded that approximately 13.71 million tons of C&D waste was generated in 2012 in Shanghai, of which more than 80% of this C&D waste was concrete, bricks and blocks. Analysis from this study can be applied to facilitate C&D waste governors and researchers the duty of formulating precise policies and specifications. As a matter of fact, at least a half of the enormous amount of C&D waste could be recycled if implementing proper recycling technologies and measures. The appropriate managements would be economically and environmentally beneficial to Shanghai where the per capita per year output of C&D waste has been as high as 842 kg in 2010.     

Kinetics study of fermentative hydrogen production from liquid swine manure supplemented with glucose under controlled pH

Kinetics of H₂ production from liquid swine manure supplemented with glucose by mixed anaerobic cultures was investigated using batch experiments under four different pH conditions (4.4, 5.0, 5.6, and uncontrolled). The temperature for the experiments was controlled at 37 ± 1°C and the length of experiments varied between 50 and 120 hours, depending upon the time needed for completion of each individual experiment. The modified Gompertz model was evaluated for its suitability for describing the H₂ production potential, H₂ production rate, and substrate consumption rate for all the experiments. The results showed that the Gompertz model could adequately fit the experimental results. The effect of pH was significant on all kinetic parameters for H₂ production including yield, production rate and lag time, and the substrate utilization rate. The optimal pH was found to be 5.0, at which a maximum H₂ production rate (0.64 L H₂/h) was obtained, and deviation from the optimal pH could result in substantial reductions in H₂ production rate (0.32 L H₂/h for pH 4.0 and 0.43 L H₂/h for pH 5.6). The results also showed that if pH was not controlled for the batch fermentation process, the substrate utilization efficiency could steeply decrease from 98.8% to 33.7%.     

Influences of adding easily degradable organic waste on the minimization and humification of organic matter during straw composting

To find a better composting process with low greenhouse gas emission and high humus production, the effect of adding kitchen waste on reduction and humification of organic matter during straw composting was studied. Three processes were compared, consisting of different ratios of straw and kitchen waste (1:2, 1:1, and 2:1). At four time points over a 62-d incubation, the reduction and humification of compost was evaluated by measuring the total mass, carbon content, and humic material content of the compost. Treatment 1 (straw/kitchen waste ratio of 1:2) reduced the total mass of compost the most. Treatment 2 (straw/kitchen waste ratio of 1:1) reduced the total carbon content the most, reflecting the highest emission of greenhouse gas. Treatment 3 produced the most humic acid material and released the lowest amount of carbon. Hence, from the point of view of reducing greenhouse gas emissions and increasing stable organic matter such as humus and humic acid during composting, treatment #3 was optimal. The three treatments resulted in significant differences in microbial biomass and enzyme activity during composting. The highest amount of active microbial biomass was associated with the largest reduction in compost mass (treatment 1). Higher proportions of straw (treatments 2 and 3), which contains more lignin, were associated with greater β-glycosidase activity, which may generate more humus that can improve soil quality. Dehydrogenase activity seemed to be the most important microbial factor in organic carbon catabolism or humification.