Treatment of Sydney N.S. tar pond sludge in a pilot‐scale rotary kiln

Tar pond wastes from Sydney, Nova Scotia, containing 50 ppm or more of polychlorinated biphenyls (PCBs) were treated in a pilot‐scale rotary kiln. In order to use the existing feed system attached to the rotary kiln, the wastes were first oven‐dried. Stack gas sampling was conducted during the test, which included measurement of volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), semi‐volatile organic compounds (SVOCs), HCl, and metals. The purpose of this study was to determine emissions from treatment of the tar pond waste using rotary kiln technology. It was found that the dried sludge could sustain combustion in the kiln without any supporting fuel. The emissions of polychlorinated dibenzodioxins/furans (PCDD/Fs) were higher than the Canadian Council of Ministers of the Environment (CCME) air emissions guidelines, and the reasons for this are discussed. © 2008 Wiley Periodicals, Inc.     

Fast transformation of roxarsone into toxic arsenic species with ferrous iron and tetrapolyphosphate

Environmental Chemistry Letters - Organoarsenic compounds have been widely used as feed additives in livestock and poultry breeding. They are excreted in manure and thus cause environmental...     

Species identification and mutation breeding of silicon-activating bacteria isolated from electrolytic manganese residue

Environmental Science and Pollution Research - A strain of silicon-activating bacteria was isolated from electrolytic manganese residue (EMR); identified as a species of Ochrobactrum by integrated...     

Study on microstructure and extinction characteristics of particulate matter in diesel engine fueled with different biodiesels

Environmental Science and Pollution Research - Biodiesel combustion particulate matter (PM) is different from diesel combustion PM in terms of microscopic morphology, which directly affects the...     

Seasonal variations of dissolved inorganic nutrients transported to the Linjiang Bay of the Three Gorges Reservoir, China

Field surveys were carried out from January 2007 to December 2008 to investigate seasonal variations of dissolved inorganic nitrogen (DIN) and phosphorus (DIP) transported to the Linjiang Bay of the Three Gorges Reservoir, China. The results revealed that both DIN and DIP exhibited large seasonal variability. DIN (dominated by NH₄?CN) concentrations were drastically higher in the dry season than those in the rainy season, and the same seasonal patterns of DIP concentrations and DIN and DIP fluxes were observed but inverse to that of DIN concentrations. The interannual variation in DIN fluxes descended by 28.2% from 2007 to 2008, while DIP fluxes increased by 40.9%, which were closely constant with interannual changes in DIN and DIP concentrations, respectively. The study indicated that nutrient fluxes (DIN and DIP) were strongly correlated with both nutrient concentrations and river discharge, and the Linjiang Bay received approximately 3,416 × 10³ kg DIN and 324 × 10³ kg DIP every year. In addition, DIN mainly originated from point sources, but DIP originated from non-point sources. It is shown that to control point source pollution is the most effective step for water quality improvement and reducing nutrient loading inputs in the Linjiang Bay.     

Triboelectrostatic separation for granular plastic waste recycling: A review

The world’s plastic consumption has increased incredibly in recent decades, generating more and more plastic waste, which makes it a great public concern. Recycling is the best treatment for plastic waste since it cannot only reduce the waste but also reduce the consumption of oil for producing new virgin plastic. Mechanical recycling is recommended for plastic waste to avoid the loss of its virgin value. As a mechanical separation technology, triboelectrostatic separation utilizes the difference between surface properties of different materials to get them oppositely charged, deflected in the electric field and separately collected. It has advantages such as high efficiency, low cost, no concern of water disposal or secondary pollution and a relatively wide processing range of particle size especially suitable for the granular plastic waste. The process of triboelectrostatic separation for plastic waste is reviewed in this paper. Different devices have been developed and proven to be effective for separation of plastic waste. The influence factors are also discussed. It can be concluded that the triboelectrostatic separation of plastic waste is a promising technology. However, more research is required before it can be widely applied in industry.     

Three-dimensional numerical simulation of water quality and sediment-associated processes with application to a Mississippi Delta lake

A three-dimensional water quality model was developed for simulating temporal and spatial variations of phytoplankton, nutrients, and dissolved oxygen in freshwater bodies. Effects of suspended and bed sediment on the water quality processes were simulated. A formula was generated from field measurements to calculate the light attenuation coefficient by considering the effects of suspended sediment and chlorophyll. The processes of adsorption–desorption of nutrients by sediment were described using the Langmuir Equation. The release rates of nutrients from the bed were calculated based on the concentration gradient across the water–sediment interface and other variables including pH, temperature and dissolved oxygen concentration.The model was calibrated and validated by applying it to simulate the concentrations of chlorophyll and nutrients in a natural oxbow lake in Mississippi Delta. The simulated time series of phytoplankton (as chlorophyll) and nutrient concentrations were generally in agreement with field observations. Sensitivity analyses were conducted to demonstrate the impacts of varying suspended sediment concentration on lake chlorophyll levels.     

Monitoring nitrogen deposition in typical forest ecosystems along a large transect in China

The nitrogen (N) deposition fluxes were investigated in eight typical forest ecosystems along the North–South Transect of Eastern China (NSTEC; based on the ChinaFLUX network) by ion-exchange resin (IER) columns from May 2008 to April 2009. Our results demonstrated that the method of IER columns was both labor cost saving and reliable for measuring dissolved inorganic nitrogen (DIN) deposition at the remote forest stations. The deposition of DIN in the throughfall ranged from 1.3 to 29.5 kg N ha^?1 a^?1, increasing from north to south along NSTEC. The relatively high average ratio of ammonium to nitrate in deposition (1.83) indicated that the N deposition along the NSTEC in China mostly originated in farming and animal husbandry rather than in industry and vehicle activities. For seasonal variability, the DIN deposition showed a single peak in the growing season in the northern part of NSTEC, while, in the southern part, it exhibited double-peaks in the early spring and the mid-summer, respectively. On the annual scale, the DIN deposition variations of the eight sites could be mainly explained by precipitation and the distances from forest stations to provincial capital cities.     

汽车制造厂废水处理工程实例分析

采用二级混凝-气浮-水解酸化-SBR-过滤工艺，对某汽车制造厂的混合废水（包括脱脂废水、电泳废水、磷化废水和生活污水等）进行处理。经过对处理工艺进出水主要水质指标连续1个月的监测，发现COD去除率可达92．5％，SS去除率可达95．2％，NH3-N去除率可达58％，TP去除率可达96．7％，出水水质符合国家《污水综合排放标准》（GB8978—1996）一级排放标准，吨水处理成本为1．6元／t，系统运行稳定，具有明显的经济、环保和社会效益。t     

我国对电池和涂料产品实行消费税绿色调控

2015年初国务院相关部门发布通知,对电池和涂料产品征收消费税。本文结合消费税绿色化改革方向,阐述了此次消费税扩围的内容和特点,分析了消费税绿色化在促进环境保护中的作用,提出了将电池和涂料产品纳入消费税的影响和建议。