石灰石高温煤气脱硫的试验研究

采用天然石灰石做脱硫剂,在固定床上进行硫化氢高温脱除的试验研究,考察了脱硫剂粒径、反应温度、气速及高温煤气中H2对石灰石脱硫性能的影响,同时还用热重分析(TG)、扫描电镜(SEM)、X-射线衍射(XRD)等测试手段对脱硫剂的物相组成和结构等进行了表征。结果表明,脱硫剂的粒径对脱硫效果的影响很大,0.38～0.83 mm的石灰石脱硫效果最佳;温度对脱硫效果的影响比较复杂,最佳的操作温度为850℃;气速对脱硫效果的影响较明显,脱硫剂的穿透时间随气速的减小而加长;H₂对脱硫过程起阻碍作用,气速越小,这种阻碍作用越明显。     

A preliminary assessment of the potential environmental and human health impact of unsymmetrical dimethylhydrazine as a result of space activities

A preliminary assessment of the potential environmental and human health impact of UDMH as a result of space activities has been carried out applying a theoretical approach in comparison with selected experimental data. The theoretical framework includes QSAR, ADME and PASS modelling as well as studies on the possible atmospheric dispersion of UDMH as calculated applying the OML-Multi model. The possible impact on the environment and the human health has been elucidated and it has been concluded that UDMH especially inside the fall region of burned-out rocket stages constitute a significant threat to both environmental and human health, the latter as a results of the carcinogenic, mutagenic, convulsant, teratogenic and embryotoxic characteristics of UDMH in addition to the general toxic characteristics of the compound.     

Analytical estimation of elasticity of cyclone effectiveness factor

The elasticity of a cyclone effectiveness factor has been determined with respect to all the design and operating parameters of cyclone. Cooper's (1983) method of numerical treatment, which essentially involves the estimation of the fractional change in the effectiveness factor per unit fractional change in the variable (keeping all other variables at the base values) has been utilized to analyse analytically. Leith-Licht and Shepherd-Lapple equations are used for the purpose. The advantages of analytical treatment has been demonstrated with illustrations.     

Air Pollution Impacts to Some Important Species of Pine

In the past, many species of pine have been severely damaged by acute forms of air pollution associated with ore smelting. More recently, damage to ponderosa pine in the state of Washington has been associated with atmospheric fluoride, and this species in particular has also suffered smog damage in southern California. In the East, white pine has been declining in the vicinity of certain soft-coal-burning power plants, and in one case downwind from an oil-burning power plant: also, throughout the East, an atmospheric oxidant of unknown source has caused a type of needle blight on white pine. Trash burners and city dump combustion have led to the hilling of certain pine species, leaving other intermixed pine species unharmed. Localized damage to white pine from automobile exhaust has been observed. Differences in the susceptibility of neighboring trees of the same species to a given air pollutant have been observed repeatedly.     

Concentration,sources and particle size distribution of the atmospheric aerosol of the oviedo urban nucleus (Spain)

The average hourly variation of particle concentration and its charged fraction has been determined in the city of Oviedo (Spain). The population density in the central zone of Oviedo, a city of 180,000 inhabitants, is one of the highest in Europe. The city is not very industrialized.The average particle size distribution in winter and summer has been studied resulting in unimodal spectra, which are fitted to a log-normal distribution.It has been demonstrated that the average distributions in the city of Oviedo are a direct consequence of two primary sources, traffic and heating systems.     

The Case of Sarno River (Southern Italy). Effects of geomorphology on the environmental impacts (8 pp)

Background, Aim and Scope Analysis of the morphological, geological and environmental characteristics of the Sarno River basin has shown the present degraded condition of the area. Over the past thirty years, the supply of untreated effluent of domestic, agricultural and industrial origin has ensured the presence of high concentrations of pollutants, including heavy metals. The geological context of the catchment area has played a major part in determining the current ecological conditions and public health problems: while human activity has modified the landscape, the natural order has indirectly contributed to increasing the environmental impact. Results and Discussion The health situation is precarious as the basin's inhabitants feed on agricultural and animal products, and use polluted water directly or indirectly. The hazard of contracting degenerative illnesses of the digestive or respiratory apparatus, bacterial infections or some neoplasia has gradually increased, especially in the last five years. Moreover, polluted basin waters flowing into the Bay of Naples increase sea water contamination, thereby damaging tourism, public health and degrading the local littoral quality. Conclusion The overview presented shows how the environmental state of the Sarno River basin gives considerable cause for concern. The basin's complex geomorphologic setting has a direct bearing on local environmental and health conditions. The analysis of the available data demonstrates how the physical aspects of the area are closely linked to the diffusion and concentration of the pollutants, and how the latter ones have a large influence on the hygienic-sanitary conditions of the local population. Recommendation and Perspective Specific interventions need to be undertaken to monitor and improve the chemical, physical and microbiological conditions of water and sediments, especially in light of the geomorphological vulnerability of the river basin.     

Effects of biowaste-derived biochar on the dynamic behavior of cadmium fractions in soils

Environmental Science and Pollution Research - As a commonly used amendment to soil contaminated by heavy metals, biochar has attracted great attention and has been applied for decades due to the...     

固硫型煤的生产技术和使用效果

针对链式炉炉内脱硫，设计了固硫型煤生产线，通过测试、试验、生产和实际使用，使固硫型煤满足脱硫要求，同时，节能效果也较明显。另外，对固硫剂、粘结剂的选用和配比作了介绍。     

Potential therapeutic effect of Chrysopogon zizanioides (Vetiver) as an anti-inflammatory agent

Environmental Science and Pollution Research - Vetiver has a broad history of traditional medicinal uses, but only a handful of research article has reported its utility in treating diseases. But...     

The state of ambient air quality in Pakistan—a review

Background and purpose  

Pakistan, during the last decade, has seen an extensive escalation in population growth, urbanization, and industrialization, together with a great increase in motorization and energy use. As a result, a substantial rise has taken place in the types and number of emission sources of various air pollutants. However, due to the lack of air quality management capabilities, the country is suffering from deterioration of air quality. Evidence from various governmental organizations and international bodies has indicated that air pollution is a significant risk to the environment, quality of life, and health of the population. The Government has taken positive steps toward air quality management in the form of the Pakistan Clean Air Program and has recently established a small number of continuous monitoring stations. However, ambient air quality standards have not yet been established. This paper reviews the data being available on the criteria air pollutants: particulate matter (PM), sulfur dioxide, ozone, carbon monoxide, nitrogen dioxide, and lead.     

Conventional pyrolysis of Plastic waste for Product recovery and utilization of pyrolytic gases for carbon nanotubes production

Environmental Science and Pollution Research - Inevitably increase in plastic demand has resulted in an overgrowing production on a global scale. The utilization of plastics has been applied to a...     

Connecting the dots between inflammatory cascades of obesity and COVID-19 in light of mortal consequences—a review

Environmental Science and Pollution Research - Obesity is a term that has recently been referred to describe a condition in which a person has become a diseased vessel. Obesity’s internal...     

Aqueous solubility, effects of salts on aqueous solubility, and partitioning behavior of hexafluorobenzene: experimental results and COSMO-RS predictions

The aqueous solubility of hexafluorobenzene has been determined, at 298.15 K, using a shake-flask method with a spectrophotometric quantification technique. Furthermore, the solubility of hexafluorobenzene in saline aqueous solutions, at distinct salt concentrations, has been measured. Both salting-in and salting-out effects were observed and found to be dependent on the nature of the cationic/anionic composition of the salt. COSMO-RS, the Conductor-like Screening Model for Real Solvents, has been used to predict the corresponding aqueous solubilities at conditions similar to those used experimentally. The prediction results showed that the COSMO-RS approach is suitable for the prediction of salting-in/-out effects. The salting-in/-out phenomena have been rationalized with the support of COSMO-RS σ-profiles. The prediction potential of COSMO-RS regarding aqueous solubilities and octanol-water partition coefficients has been compared with typically used QSPR-based methods. Up to now, the absence of accurate solubility data for hexafluorobenzene hampered the calculation of the respective partition coefficients. Combining available accurate vapor pressure data with the experimentally determined water solubility, a novel air-water partition coefficient has been derived.     

超重力旋转填料床在燃煤尾气处理上的应用进展

本文指出了我国燃煤尾气脱硫进展缓慢的原因 ,介绍了一种新型的燃煤尾气脱硫设备———超重力旋转脱硫床的工作原理、传质特性及在低浓度的废气处理上的广阔应用前景     

The impact of environmental regulation on environmental pollution in China: an empirical study based on the synergistic effect of industrial agglomeration

Environmental Science and Pollution Research - In recent years, as environmental degradation has become more and more serious, the Chinese government has formulated a series of environmental...     

Investigation of Nitrogen-Bearing Species in Catalytic Steam Gasification of Poultry Litter

Abstract

The production of broiler chickens has become one of the largest sectors in U.S. agriculture, and the growing demand for poultry has led to an annual production growth rate of 5%. With increased demand for poultry, litter management has become a major challenge in the agriculture industry. Although the catalytic steam gasification has been accepted as a possible and feasible method for litter management, concern has been expressed about the presence of nitrogen and phosphorus containing species in the fuel gas and/or in the final solid residue. The possible release of phosphorus as phosphine gas in the fuel gas can have an adverse impact on the environment. Similarly, possible release of ammonia from the nitrogen containing species is also not acceptable. Hence, under partial U.S. Department of Agriculture support, a study was conducted to examine the fate and the environmental impact of the nitrogen- and phosphorus-containing species released during catalytic steam gasification of poultry litter. From various preliminary tests, it was concluded that most (～100%) of the phosphorus would remain in the residue, and some (20–70%) of the nitrogen would end up as ammonia in the fuel gas. The effects of temperature, catalyst loading, and type of catalyst on ammonia liberation were studied in a muffled furnace setup at atmospheric pressure. The fraction of nitrogen released as ammonia was found to decrease with an increase in temperature during pyrolysis and steam gasification. It also decreased with an increase in catalyst loading.     

Investigation of nitrogen-bearing species in catalytic steam gasification of poultry litter

The production of broiler chickens has become one of the largest sectors in U.S. agriculture, and the growing demand for poultry has led to an annual production growth rate of 5%. With increased demand for poultry, litter management has become a major challenge in the agriculture industry. Although the catalytic steam gasification has been accepted as a possible and feasible method for litter management, concern has been expressed about the presence of nitrogen and phosphorus containing species in the fuel gas and/or in the final solid residue. The possible release of phosphorus as phosphine gas in the fuel gas can have an adverse impact on the environment. Similarly, possible release of ammonia from the nitrogen containing species is also not acceptable. Hence, under partial U.S. Department of Agriculture support, a study was conducted to examine the fate and the environmental impact of the nitrogen- and phosphorus-containing species released during catalytic steam gasification of poultry litter. From various preliminary tests, it was concluded that most (approximately 100%) of the phosphorus would remain in the residue, and some (20-70%) of the nitrogen would end up as ammonia in the fuel gas. The effects of temperature, catalyst loading, and type of catalyst on ammonia liberation were studied in a muffled furnace setup at atmospheric pressure. The fraction of nitrogen released as ammonia was found to decrease with an increase in temperature during pyrolysis and steam gasification. It also decreased with an increase in catalyst loading.     

Texas Regulation Requires Control of Opacity Using Instrumental Measurements

For over four years, a Texas air pollution control regulation has been in force which permits use of a stack mounted transmissometer instrument to measure visible emissions, thus avoiding the necessity for visual observations. Many types of industrial plants have installed instruments, and extensive experience has been obtained with this method of measurement and control. Plant operators and enforcement officials have expressed a strong preference for this method, both to demonstrate compliance and to provide data to aid in operating control equipment. Some operational problems have been encountered, but these usually can be overcome with proper care. Because of the advantages obtained with this regulation a new regulation has been adopted which makes the instrumental method mandatory for large sources of visible emissions.     

甲基叔丁基醚的污染治理技术研究进展

甲基叔丁基醚(MTBE)是一种无铅汽油添加剂,其广泛使用造成了土壤和地下水污染;同时对人类有可疑致癌作用,因此成为人们关注的焦点.对近年来国外MTBE的污染治理技术研究进展进行了综述,并对主要方法进行了对比.在适宜的微生物存在条件下,MTBE的生物降解是可以发生的;植物修复技术可用于地下水和土壤污染治理;物理化学方法种类繁多,包括吸附和高级氧化等,其处理效率高成本也较高;新的处理技术如渗透性活性障壁PRB、膜分离/催化技术等也在研究之中.     

Development of a new model for batch sedimentation and application to secondary settling tanks design.

Assuming that settling takes place in two zones (a constant rate zone and a variable rate zone), a model using four parameters accounting for the nature of the water-suspension system has been proposed for describing batch sedimentation processes. The sludge volume index (SVI) has been expressed in terms of these parameters. Some disadvantages of the SVI application as a design parameter have been pointed out, and it has been shown that a relationship between zone settling velocity and sludge concentration is more consistent for describing the settling behavior and for design of settling tanks. The permissible overflow rate has been related to the technological parameters of secondary settling tank by simple working equations. The graphical representations of these equations could be used to optimize the design and operation of secondary settling tanks.