泥炭和褐煤对Zn^2＋,Cu^2＋,Pb^2＋等重金属离子的吸附特征

利用天然有机吸附剂泥炭和褐煤对重金属离子Ｚｎ＾２＋，Ｃｕ＾２＋，Ｐｂ＾２＋的单组分水溶液进行吸附研究。对吸附模型，吸附时间，不同吸附剂投放量，金属离子种类等给予表征，基本符合Ｌａｎｇｍｕｉｒ吸附等温线。     

开发洋口港的自然优势和宏观功能

本文根据近几年对洋口港的调查实测资料，分析了建深水港的可行性，并提出为解决长江口通海航道水深不足，充分发挥南通港港群机能等问题，供有关部门参考。     

水质评价中的宽域灰色决策法

依据灰色决策的基本原理，结合环境质量评价的实际情况，用宽域式结构建立隶属函数，提出宽域灰色决策法，并以水质评价为例进行了尝试。结果表明，宽域灰色决策法的评价结果比较符合实际状况，比模糊数学法和灰色聚类法的评价结果更为合理。     

氮肥工业中氨氮废水治理技术进展

介绍了氮肥厂对合成氨低温变换工艺冷凝液和尿素解吸废水的回收处理方法。认为选用热力水解法处理尿素吸废水是可行的。     

Bioaccumulation of lanthanum and cerium and their effects on the growth of wheat (Triticum aestivum L.) seedlings

Through short-term exposure (7-d exposure), long-term exposure (16-d exposure) and exposure-recovery (7-d exposure + 9-d recovery), the bioaccumulation and distribution of La and Ce and their effects on growth of wheat seedlings were studied. Addition of La (0.5-25 mg/l) and Ce (0.5-25 mg/l) to the culture medium individually and in combination inhibited primary root elongation, reduced the dry weight of roots and shoots and the content of mineral elements (Ca, Mg, K, Cu, Zn). The damage increased with an increase in the concentrations of La and Ce in culture medium. Relative damage ratio increased with an increase in concentrations of La and Ce in the culture medium and with exposure time. Comparing exposure-recovery groups with long-term exposure groups, primary root lengths, dry weight of roots and shoots and the content of five mineral elements were higher. The accumulation of La and Ce in the seedlings was positively correlated with the concentrations of La and Ce in the culture medium and with exposure time. Bioaccumulation factors of La and Ce in roots were much higher than those of shoots. The uptake rates of La and Ce by the plants were much higher than the translocation rates from roots to shoots. The accumulation and distribution of La and Ce in the seedlings in exposure-recovery groups showed that there was very little excretion through metabolism during the recovery period, but redistribution occurred throughout the whole plant. No apparent selective uptake was found between La and Ce by the plants when they were applied in combination.     

Key factors affecting spatial variation of methane emissions from freshwater marshes

To understand the mechanism for spatial variation of CH(4) emissions from marshes grown with different type of plants in a region and plots within a certain marsh grown with one type of plants, we measured CH(4) emissions from a region in which eutrophic freshwater marshes were divided into three types: Carex lasiocarpa, Carex meyeruana and Deyeuxia angustifolia according to plant type as well as CH(4) concentration in porewater, aboveground plant biomass and stem density in situ in Sanjiang Plain of Northeast China in August 2001. Spatial variation of CH(4) emissions from both different marshes in a region and different plots within a certain marsh was high. The flux rates of CH(4) emissions from three marshes ranged from 17.2 to 66.5 mg CH(4) m(-2)h(-1) with 34.76% of variation coefficient, whereas the values in Carex lasiocarpa, Carex meyeriana and Deyeuxia angustifolia marshes varied from 21.6 to 66.5 (39.61%), from 17.2 to 45.0 (29.26%) and from 19.1 to 33.0 mg CH(4) m(-2)h(-1) (17.51%), respectively. Both the flux rates and spatial variation of CH(4) emissions strongly increased as standing water depth increased significantly. Standing water depth greatly governed the spatial variation of CH(4) emissions from different marshes in a region by changing the amount of plant litters inundated in standing water, which provided labile organic C for methanogens and controlled CH(4) concentrations in porewater. Moreover, the aboveground plant biomass determined spatial variation of CH(4) emissions from plots within a certain marsh by controlling the pathways (stem density) of CH(4) emissions from the marsh into the atmosphere.     

废水吸附法除磷的研究进展

本文叙述了利用吸附原理进行废水除磷的研究进展。吸附法除磷的研究主要表现在吸附材料的研究方面 ,基于应用场合的差异 ,包括廉价的天然材料、工业废渣及其改性物、传统的活性氧化铝及其改性物、其他多孔物质及人工合成的高效吸附剂等。人工合成高效吸附剂由于磷吸附容量大 ,其相关研究成为近年来的重要发展方向     

Temporal and spatial statistical analysis of ambient air quality of Assam (India)

ABSTRACT

Present paper represents the spatio-temporal variation of air quality and performances of geostatistical tools for the identification of pollutants zone in various districts of Assam (India). Geographic Information System (GIS) and geostatistical analysis were utilized to estimate the spatio-temporal variations (2015–2017) of gaseous and particulate air pollutants. Data of 23 fixed monitoring stations were collected from the Central Pollution Control Board (CPCB). It was observed that SO₂ and NO_x concentrations are the major pollutants to the deterioration of air quality in Assam State. Exploratory data analysis was considered for the determination of spatial and temporal patterns of air pollutants. Air Quality index (AQI) was calculated based on the air pollutants and particulate matter. Radial Basis Function (RBF) interpolation techniques were used to analyze the spatial and temporal variation of air quality in Assam. Cross-validation is applied to evaluate the accuracy of interpolation methods in terms of Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE), Nash–Sutcliffe Equation (NSE) and Accuracy Factor (ACFT). In 2015, the high value of AQI portrayed in the central and northeast of the state. In 2016, the central and entire east of the study area was recorded the highest value of AQI. In 2017, it was observed that mostly the central part of the state recorded the high value of AQI. The spatio-temporal variation trend of air pollutants provides sound scientific basis for its management and control. This information of air pollution congregation would be valuable for urban planners and decision architects to efficiently administer air quality for health and environmental purposes.     

二氧化钛光催化剂的表征方法研究

光催化氧化法作为一种非常具有应用前景的有机废水处理方法而成为近年来国内外的一个热点研究领域。二氧化钛因其光催化活性高、适用范围广等优点而引起众多研究者的重视 ,这方面的研究已取得了许多成果。二氧化钛光催化活性的强弱直接影响到该方法在实际中的应用。本文对影响二氧化钛催化活性的因素以及表征这些因素的方法进行了评述。     

The preparation of Zn2+-doped TiO(2) nanoparticles by sol-gel and solid phase reaction methods respectively and their photocatalytic activities

The photocatalytic oxidation of the organic pollutants with TiO(2) as photocatalyst has been widely studied in the world, and many achievements have been made. The degradation of pollutants is highly related to the photocatalytic activity of TiO(2). It is demonstrated that doping ions to TiO(2) is one way to enhance the photocatalytic activity of TiO(2). In this paper, Zn(2+)-doped TiO(2) nanoparticles were prepared through sol-gel and solid phase reaction methods, characterized by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The photocatalytic activity of the elaborated powders was studied following the degradation of Rhodamine B. The results showed that the photocatalytic activity of Zn(2+)-doped TiO(2) prepared by sol-gel method is close to that of pure TiO(2) particles, however, the photocatalytic activity of Zn(2+)-doped TiO(2) prepared by solid phase reaction method is much higher than that of pure TiO(2) particles. The most efficient degradation of Rhodamine B was found with TiO(2) particles doped with 0.5% Zn(2+) in mole and calcined at 500 degrees C. Also the reason for the enhancement of the photocatalytic activity of TiO(2) by Zn(2+) doping through solid phase reaction method was discussed.