生物氧化提金废物安全治理

随着人们对黄金需求量的增加,黄金的生产规模在不断地扩大,我国易处理的金矿资源日渐减少,人们逐渐把眼光转向难处理的金矿,同时给人类带来的环境污染日趋严重,开发无污染或少污染的选冶新技术及如何安全环保的处理提金产生的废物,越来越受到广大从事黄金提取科技工作者的关注。生物氧化提金工艺的出现解决了此问题。生物氧化法具有投资少,金的回收率高,工艺操作简单,不污染环境等优点,此方法已成为开发难处理低品位金矿石的主要方法。我国自2000年开始投入使用,近几年,它的发展在中国相当迅速。本文介绍了我国新疆金铬矿业有限公司的生物氧化提金工艺及环废物处理情况,概述了其他提金废物处理的进展,旨在促进我国生物氧化提金清洁提取技术的发展。     

Integrated soil-crop system management: reducing environmental risk while increasing crop productivity and improving nutrient use efficiency in China

During the past 47 yr (1961-2007), Chinese cereal production has increased by 3.2-fold, successfully feeding 22% of the global human population with only 9% of the world's arable land, but at high environmental cost and resource consumption. Worse, crop production has been stagnant since 1996 while the population and demand for food continue to rise. New advances for sustainability of agriculture and ecosystem services will be needed during the coming 50 yr to reduce environmental risk while increasing crop productivity and improving nutrient use efficiency. Here, we advocate and develop integrated soil-crop system management (ISSM). In this approach, the key points are (i) to take all possible soil quality improvement measures into consideration, (ii) to integrate the utilization of various nutrient resources and match nutrient supply to crop requirements, and (iii) to integrate soil and nutrient management with high-yielding cultivation systems. Recent field experiments have shed light on how ISSM can lead to significant increases in crop yields while increasing nutrient use efficiency and reducing environmental risk.     

Impacts of climate change/variability on the streamflow in the Yellow River Basin, China

Changes of streamflow reflect combined effects of climate, soil and vegetation in the basin scale. This study was conducted to investigate the response of streamflow to the climate changes/variability in different scales of the Yellow River Basin (YRB). The spatial distribution and temporal trends were explored for precipitation and potential evapotranspiration (PE) during 1961-2000 to illustrate climate change/variability and impacts of climate change/variability on streamflow were explained by investigating the relationship of precipitation, PE and streamflow in the YRB. The results presented that: (i) precipitation and PE exhibited different spatial distribution patterns and temporal trends in different regions, and most stations showed negative trends for precipitation in the basin; (ii) the relationship of streamflow with precipitation and PE showed high nonlinearity, and the magnitudes and patterns of streamflow response to precipitation and PE displayed different patterns varied with the dry conditions in different region or years; and (iii) the precipitation elasticity of streamflow (?_P) was 1.80, 1.08, 1.78 and 1.95 in Lanzhou, Toudaoguai, Huayuankou and Lijin respectively, while the PE elasticity of streamflow (?_ET) was −3.41, −4.40, −4.52 and −4.20 in above four scales, respectively, from which can be seen that streamflow was more sensitive to precipitation in wet region than in arid region and inversely it was more sensitive to PE in arid regions than in wet regions. Furthermore, precipitation elasticity of streamflow calculated from the partial correlation presented a reasonable result to show the combined effect of precipitation and PE on streamflow.     

Potential application of sludge produced from coal mine drainage treatment for removing Zn(II) in an aqueous phase

Various analyses of physico-chemical characteristics and batch tests were conducted with the sludge obtained from a full-scale electrolysis facility for treating coal mine drainage in order to find the applicability of sludge as a material for removing Zn(II) in an aqueous phase. The physico-chemical analysis results indicated that coal mine drainage sludge (CMDS) had a high specific surface area and also satisfied the standard of toxicity characteristic leaching procedure (TCLP) because the extracted concentrations of certain toxic elements such as Pb, Cu, As, Hg, Zn, and Ni were much less than their regulatory limits. The results of X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) showed that the CMDS mainly consists of goethite (70%) and calcite (30%) as a weight basis. However, the zeta potential analysis represented that the CMDS had a lower isoelectric point of pH (pH_IEP) than that of goethite or calcite. This might have been caused by the complexation of negatively charged anions, especially sulfate, which usually exists with a high concentration in coal mine drainage. The results of Fourier transform infrared (FT-IR) spectrometry analysis revealed that Zn(II) was dominantly removed as a form of precipitation by calcite, such as smithsonite [ZnCO₃] or hydrozincite [Zn₅(CO₃)₂(OH)₆]. Recycling sludge, originally a waste material, for the removal process of Zn(II), as well as other heavy metals, could be beneficial due to its high and speedy removal capability and low economic costs.     

Atmospheric NO2 and NH3 deposition into a typical agro-ecosystem in Southeast China

The dry deposition of atmospheric nitrogen (including NO(2) and NH(3)) into a typical agro-ecosystem in Southeast China during 2006-2007 was estimated. Results indicated that the dry deposition velocities of NO(2) and NH(3) ranged from 0.04-0.24 cm s(-1) and 0.09-0.47 cm s(-1), respectively. The higher values appeared in the non-crop growing period. Concentrations of atmospheric NO(2) and NH(3) ranged from 24.64-104.10 μgN m(-3) and 14.40-389.6 μgN m(-3), respectively. Variation of the NH(3) mixing ratio showed a clear double-peak. NO(2) and NH(3) deposition fluxes were 74.68-80.75 kgN ha(-1), which was equivalent to 162.4 and 175.5 kg ha(-1) of urea applied in 2006-2007. The N deposition fluxes were 13.91-40.38 and 5.33-22.73 kgN ha(-1) in peanut and rice growing periods, accounting for 8.18%-40.38% and 2.13%-23.06% of N fertilizer usages, respectively. NO(2) and NH(3) deposition were significant for the red soil farmland.     

Size distribution and seasonal variations of particle-associated organochlorine pesticides in Jinan, China

The concentrations of organochlorine pesticides (OCPs) in atmospheric particulate matter in Jinan, China, over the period from July 2009 to June 2010, were determined to study their pollution levels, compositions, size distribution and seasonal variations. All target compounds except endosulfan sulfate were detected. The annual average concentration of ∑18 OCPs was 92 ± 82 pg m(-3). Total HCH, total endrin, aldrin, endosulfan compounds and total DDT compounds were the primary components, accounting for approximately 27%, 20%, 16%, 14% and 10% of total OCPs, respectively. The annual mean ng g(-1) concentrations of ∑18 OCPs in PM(2.5), PM(5), PM(10) and TSP were 481 ± 190, 433 ± 161, 414 ± 158 and 264 ± 193, respectively, indicating that most OCPs tend to be strongly absorbed by fine air particles which were strongly related to a potential health risk. Distinct seasonal trends were found in OCPs concentrations with high concentrations appearing in November and March whereas low concentrations appeared in the summer, which were significantly positively correlated with particulate mass concentrations and Air Pollution Index (API). The high OCPs levels could be attributed to the seasonal usage, long-range atmospheric transport as well as adverse meteorological conditions.     

Occurrence and behavior of non-steroidal anti-inflammatory drugs and lipid regulators in wastewater and urban river water of the Pearl River Delta, South China

Occurrence of five non-steroidal anti-inflammatory drugs (salicylic acid, ibuprofen, naproxen, indomethacin and diclofenac) and three lipid regulators (bezafibrate, clofibric acid and gemfibrozil) was investigated in wastewater, sewage sludge, and river water of the urban section of the Pearl River at Guangzhou in South China. Behavior and fate of the pharmaceuticals during treatment in two sewage treatment plants (STPs) were also studied in depth by determining concentrations in the influents and effluents at major treatment units and the sewage sludge. Concentrations of the pharmaceuticals in the raw wastewater were mostly at ng L(-1) levels except salicylic acid whose concentrations ranged from 9.6 to 23.3 μg L(-1). No significant amount of the pharmaceuticals was detected in the suspended particulate matter of wastewater and sewage sludge. Salicylic acid, indomethacin, and naproxen were almost completely removed (≥ 99%); gemfibrozil, ibuprofen and bezafibrate were significantly removed (>75%), whereas diclofenac and clofibric acid were removed by 60-70% during treatment in the STPs. Generally, biodegradation was the governing process for elimination of the investigated pharmaceuticals. Anaerobic biodegradation was responsible for most of the removal of diclofenac whereas aerobic biodegradation also played an important role in elimination of the other pharmaceuticals except SA, which was nearly completely removed after the anoxic process. In the Pearl River, the pharmaceuticals were widely detected. Both the concentrations and detection frequency were higher in March 2008 than those in the other seasons, which may be ascribed mainly to less dilution caused by lower precipitation. Besides the STPs, urban canals directly connected with the Pearl River may also be important contributors to the pharmaceutical contamination in the river.     

Hydrodynamics and water quality of the Hongze Lake in response to human activities

Environmental Science and Pollution Research - The hydrodynamics and water quality of a lake in response to human activities is an important yet poorly understood issue. In this study, the...     

Microalgal-bacterial granular sludge process outperformed aerobic granular sludge process in municipal wastewater treatment with less carbon dioxide emissions

Environmental Science and Pollution Research - The aerobic granular sludge (AGS) process and microalgal-bacterial granular sludge (MBGS) process were comparably applied for municipal wastewater...     

Safety evaluation and ibuprofen removal via an Alternanthera philoxeroides-based biochar

Environmental Science and Pollution Research - Pharmaceutical and personal care products (PPCPs) are a representative class of emerging contaminants. This study aimed to investigate the PPCP...