Effluents and residues from industrial sites for carbon dioxide capture: a review

The adverse effects of climate change calls for the rapid transformation of manufacturing processes to decrease the emissions of carbon dioxide. In particular, a lower carbon footprint can be achieved by capturing carbon dioxide at the site of emission. Here we review the use of industrial effluents, waste and residues to capture carbon dioxide. Waste include steelmaking slag, municipal solid waste incinerator ashes, combustion fly ash, black liquor, paper mill waste, mining waste, cement waste, construction and demolition waste, waste from the organic industry, and flue gas desulfurization gypsum waste. Capture capacities range from 2 to 800 kg of carbon dioxide per ton of waste, depending on processes, waste type and conditions. Cement waste and flue gas desulfurization gypsum waste show the highest capture capacity per ton of waste.

     

Higher nitrates, P and lower pH in soils under medicinal plants versus crop plants

This report shows a higher soil quality under medicinal plants versus food-crop plants. Long-term continuous cultivation of food crops induces changes of soil properties that can lead to fertility loss and, in turn, decline of food productivity. Effect of cropping on soil changes has been studied mainly for food crops and vegetables worldwide, whereas soil changes in herbal fields are scarcely known. Therefore, we compared here soil nutrients and soil chemical properties of herbal fields, cultivated with Chinese medicinal plants, and food-crop fields. Fields are located at the famous traditional planting base of Chinese medicinal plants in Anguo, China. The results showed that in herbal fields, soil nitrate, available P, soil organic matter (SOM), and electrical conductivity decreased with soil depth, whereas soil pH and soil water content increased with depth. In herbal fields, soil nitrate, available P contents, and soil electrical conductivity were higher than those of food-crop fields at various soil layers. SOM and soil water content were similar in herbal and food-crop fields. Soil pH of herbal fields at 0–20 cm was lower than those of food-crop fields. Findings show overall that soil nutrient accumulation and changes under medicinal plants are higher than food-crop fields.     

Efficiency and environmental impacts of electricity restructuring on coal-fired power plants

We investigate the efficiency and environmental impacts of electricity market restructuring by examining changes in fuel efficiency, cost of coal purchases, and utilization among coal-fired power plants based on a panel data set from 1991 to 2005. Our study focuses exclusively on coal-fired power plants and uses panel data covering several years after implementation of restructuring. The estimation compares how investor-owned (IOs) plants in states with restructuring changed their behavior relative to IOs in states without. Our analysis finds that restructuring led to: (1) a 1.4 percent improvement in fuel efficiency, (2) an 8 percent decrease in unit cost of heat input, and (3) a lower capacity factor even after adjusting for cross-plant generation re-allocation due to cost reductions. The estimates imply that restructuring has led to nearly 15 percent savings in operating expenses and up to 7.5 percent emissions reduction among these plants.     

广州市园林绿化植物苗木对二氧化硫和二氧化氮吸收能力分析

采用人工模拟熏气法,研究了36种广州市园林绿化植物对SO2和NO2气体吸收净化能力,以系统聚类分析方法为依据,将参试植物的吸收净化能力划分为强性、较强、中等、较弱及弱5个等级。结果显示,在不同SO2质量浓度（0.259和0.448 mg.m-3）环境下,黄槐、鸡冠刺桐、红花银桦、木棉、红千层、大花紫薇、复羽叶栾树吸收SO2能力具有强或较强的能力,而罗汉松、竹柏、深山含笑、乐昌含笑、观光木、樟树、阴香、双翼豆、印度紫檀、大花五桠果、长芒杜英、五月茶、海南蒲桃、芒果、海南红豆、糖胶树和幌伞枫吸收SO2能力表现为较弱或弱;在NO2质量浓度（0.149和0.428 mg.m-3）环境下,黄槐、黄葛榕、红花银桦、红千层、麻楝、复羽叶栾树、大花紫薇和小叶榄仁吸收净化NO2能力为较强或强,而深山含笑、五月茶、芒果、海南红豆、糖胶树和桂花叶片对NO2吸收能力表现为较弱或弱。在不同SO2和NO2浓度环境下,黄槐、红花银桦、红千层、复羽叶栾树和大花紫薇叶片对SO2和NO2吸收净化能力表现为强或较强,而深山含笑、五月茶、芒果、海南红豆、糖胶树叶片对SO2和NO2吸收净化能力为较弱或弱。研究结果为珠三角城市功能型园林植物选择和广东生态景观林带建设提供科学依据。     

The theory of power and efficiency in ecology

Some previous work on the theory of power and optimal efficiency in ecology is shown to be either incorrect or of limited applicability. The standard analysis based on Atwood's machine is not valid, and the optimal efficiency for maximum power production depends on the characteristics of the individual system. For optimally foraging aquatic organisms the theoretical efficiency is less than 50% when the hydrodynamic flow is laminar, but under turbulent conditions the optimal efficiency can rise as high as 67%. Despite these restrictions it still appears plausible that ecological efficiency should be the same for broad classes of living organisms.     

High retention volume covalent organic polymer for xenon capture:Dynamic separation of Xe and Kr

Xenon capture and Xe/Kr separation are important processes in industry.For instance,Xe/Kr separation is an indispensable step in recycle and treatment of nuclear fuel emission.Among different separation methods,selectively adsorb gas molecules using porous materials is a promising way to reduce the high energy consumption in traditional cryogenic distillation.However,many reported adsorbents still face the challenges of:ⅰ) poor separation property at low Xe/Kr concentrations;ⅱ) insufficient rete...     

Trends of environmental accidents and impact factors in China

An overview of the spatial and temporal variations of the environmental accidents in China in recent years was presented in this paper using available data. The results showed that the frequency of pollution accidents was significantly decreased, from 3462 in 1990 to 462 in 2007. The water and air pollution accidents were found to be the dominant types, accounting for more than 80% of the total accidents. Considering the classification of environmental accidents at 4 scales, the general environmental accident, i.e., the least serious type, was the most frequent event, taking up 58.98% of the total pollution accidents. In addition, the distribution of environmental accidents was generally in accordance with the industrial layout in the country during the past decade. It is very important to note that the extraordinarily severe environmental accidents showed an increasing trend in underdeveloped regions, which was caused by the transfer and the development of heavy polluted industry in these areas. As to the losses of environmental accidents, the casualties presented an obvious reduction tendency, while the direct economic loss per accident tended to climb up. Furthermore, some key factors that affect the spatial and temporal tendencies of environmental accidents in China were discussed and some suggestions were put forward, hoping to shed light on environmental risk management and emergency plans making associated with environmental accidents in China.     

湿式旋转溶蚀器对二氧化硫吸收效率和测量干扰的评估

利用大气细颗粒物水溶性离子在线监测仪(Marga 1S)分别与API 100E和Thermo 43i同时测量环境空气和二氧化硫(SO2)标气,进而评估了湿式旋转溶蚀器对SO2吸收效率及其测量干扰.研究结果显示,基于API 100E和Marga 1S测得的2017年南京市环境空气SO2浓度分别为(17.1+7.7)μg·...     

Comparative study on the efficiency and environmental impact of two methods of utilizing polyvinyl chloride waste based on life cycle assessments

Two processes of utilizing polyvinyl chloride （PVC） waste, an incineration process and a vacuum pyrolysis process, for energy conversion were compared to determine their efficiency and environmental perfor- mance. We carried out a life cycle assessment with each of the two processes to evaluate their environmental impact and defined the goals and limits of our remit. As well, we established an inventory of PVC waste from incineration and vacuum pyrolysis based on process analysis, data collection and calculations. The results show that electrical power output per unit mass of PVC waste in the incineration process was twice as high as that of the vacuum pyrolysis process. Incineration had a larger total environmental impact potential than vacuum pyrolysis. The total environmental impact potential of PVC waste from incineration was three times higher than that from vacuum pyrolysis. Incineration of PVC disposed 300 ng. 100 kgI of dioxins and vacuum pyrolysis 98.19 ng- 100 kgI of dioxins. As well, we analyzed the data for their uncertainty with results quantified in terms of three uncertainties： basic uncertainty, additional uncertainty, and computational uncertainty. The coefficients of variation of the data were less than 25% and the quality of the inventory data was acceptable with low uncertainty. Both PVC waste disposal processes were of similar quality and their results comparable. The results of our life cycle impact assessment （LCIA） showed considerable reliability of our methodology. Overall, the vacuum pyrolysis process has a number advantages and greater potential for development of PVC disposal than the incineration process.     

Aspects and prospects of algal carbon capture and sequestration in ecosystems: a review

Long-term storage of carbon dioxide (CO₂) and other forms of carbon in non-atmospheric reservoirs is called carbon sequestration. Selective anthropogenic enrichment of the atmospheric carbon pool is causing dire environmental problems, thereby necessitating remediation by mitigation. Algae possess efficient carbon concentrating mechanisms and consequently high photosynthetic rates which make them suitable candidates for biosequestration of CO₂. Globally, nearly half of the atmospheric oxygen is generated by algal photosynthesis despite the fact that algae account for less than 1% of photosynthetic biomass. In water bodies, algae are responsible for creating the ‘biological pump’ that transports carbon from the upper sunlit waters to the depth below. A diverse array of photoautotrophs ranging from prokaryotic cyanobacteria to eukaryotic algae such as Chlorophytes, and even protists like euglenoids, contribute to this ‘biological pump’. It operates in a variety of aquatic ecosystems ranging from small freshwater ponds to the oceans where it has been most extensively studied. Two separate but intricately linked processes constitute this ‘biological pump’, viz. the ‘organic carbon pump’ and the ‘calcium carbonate pump’. The present review discusses the natural CO₂ sequestration processes carried out by algae and cyanobacteria in their native ecosystems.     

The agricultural impact of opencast coal mining in England and Wales

Opencast coal mining in England and Wales can cause a wide range of environmental problems which are increasingly public issues due to the planned expansion in output and the impact this may have on agriculture and landscape. Opencast mining is reviewed on a county by county basis to identify the variations in the disturbance caused. A detailed review of restoration techniques and the agricultural quality of the restored land is presented, and the role of Planning Authorities is discussed. Significant variations in the impact of opencast operations are identified, especially in relation to the potential for derelict land reclamation and the grade of agricultural land affected. The latter is generally lower grade 3 and below, although in certain areas operations are entering land of higher agricultural and scenic quality. The quality of restoration, while good, still has scope for improvements, such as reducing soil compaction and the subsequent management of the land by the farmer. The impact on agricultural productivity is difficult to assess, but it appears to be only slight in those cases where recent restoration techniques were used and when lower grade agricultural land is taken.     

Optimal sequestration of carbon dioxide and phosphorus in soils by gypsum amendment

Gypsum has been applied as a natural fertilizer and soil amendment for centuries in agriculture for providing crop nutrients such as Ca and S, and for improving soil physical properties. Recently, gypsum has been tested for sequestrating CO₂ from the air and for capturing soluble phosphates in the soil, through formation of insoluble calcium phosphates and carbonates. However, the environmental factors controlling these sequestration processes have not been systemically studied. Here, we calculate optimal conditions of sequestration using chemical equilibrium modeling. Our results show that CO₂ carbonation is effective at pH higher than 8.5 at atmospheric concentration. The removal of P is higher than 80 % for pH higher than 6.4, when Ca and P are at stoichiometric ratio. Also, placement of gypsum in subsoil is more effective for CO₂ capture than applying it on soil surface since soil pores often contain higher concentrations of CO₂ due to the soil respiration process. Overall, increases in medium pH, gypsum application rate, or CO₂ partial pressure can increase the effectiveness of the amendment.     

The use of systems diagrams for environmental impact assessment: Procedures and an application

The utility of systems diagrams and of energy as a unit of measure for environmental impact assessment is illustrated using results from the White Sands Missile Range, New Mexico Environmental Impact Statement. A set of procedures for developing and evaluating the diagrams is given and applied to White Sands. The utility of results obtained using this method is compared to those obtained from other methods, and the inadequacies of each are discussed.These procedures guide data collection; organize and summarize data; make explicit interactions between the environment and the “proposed project”; place various kinds of impacts and alternatives in perspective with each other and with the entire system; identify components of a macroscale system which need microscale analysis; and permit quantification of total impact and quantitative comparisons of impact types, of alternatives, and of environmental control strategies. The procedures do not guarantee that important impacts have not been overlooked, do not deal with so called aesthetic impacts, and do not guarantee that the appropriate system boundary has been chosen.Impacts at White Sands were evaluated at two system levels of detail. At a macroscale, five types of impacts resulting from missile range activities were analyzed. Results indicated that stresses on the environment caused by those activities represent 1.0% of the natural energy flow through the system. At a more detailed level of analysis, the effect of water consumption by the Missile Range on the aquifer from which the water is obtained was analyzed by means of a hydrologic model. Model simulations indicated that salt water intrusion into the aquifer was eminent and identified two aquifer management strategies that could prevent that intrusion.     

Heavy metal distribution in soils near Palapye, Botswana: an evaluation of the environmental impact of coal mining and combustion on soils in a semi-arid region

Morupule Colliery near Palapye in eastern Botswana is the only coalmine in production in Botswana at present. Its coal is mainly used in the nearby coal-fired Morupule Power Station, which generates approximately 1,000 GWh of electricity per annum. After more than 30 years mining and more than 20 years of combustion, the sedimentation of outlet fly ash from the Morupule Power Station has increased concentrations of Cr, Ni, Zn and As by 13, 2.5, 16 and 5 ppm, respectively, in the fine portion (<53 μm) of surface soils for approximately 9 km downwind. Elements that have higher concentrations in coal have stronger small-particle association during coal combustion and are less mobile in surface soils, thus showing stronger contaminations in surface soils around the coal-fired plant. Although the degree of contamination of Cr, Ni, Zn and As from coal combustion in the Palapye area at present is low, it is necessary to monitor concentrations of these elements in surface soils routinely in the future. This study also reveals moderate Pb and Zn contaminations in the Palapye area. The former is due to the use of leaded petroleum in motor vehicle traffic and the latter is mainly due to the use of galvanized iron sheets in construction.     

The effects on electricity prices in england and wales of notional sulphur dioxide emission standards for power stations

Reducing emissions of sulphur dioxide from the electricity industry in England and Wales would require application of abatement technology and raise electricity prices through increases in marginal supply costs. Capital and operating costs of alternative abatement techniques and their application under possible long-term investment and retirement plans for the industry are discussed. An approximate halving of projected emissions is found to have an effect of the order of 5% on prices under the existing tariff structure. Reductions of up to one-fifth are found to have an effect of under 1% on electricity prices.     

Enhanced photocatalytic reduction of carbon dioxide into carbon monoxide by electric field generation and defect engineering in TiO2

Environmental Chemistry Letters - Carbon dioxide (CO2) emissions and rising fossil fuel consumption have already resulted in global warming and energy crisis. Therefore, conversion of CO2 into...     

环境因子及外源化学物质对植物花色素苷的影响

花色素苷对彩叶植物叶片呈色以及果实果皮着色的作用受到广泛重视,但关于环境因子以及外源化学物质对花色素苷的影响研究缺乏系统评述.依据国内外近10年来的相关文献.在阐述花色素苷的生理作用和实用价值的基础上,综述了光照、温度、水分、pH值等有关环境因子和有机物、植物生长调节剂、矿质元素等外源化学物质对植物花色素苷积累、含量变化以及稳定性的影响及其生理机制;结果表明,对多数彩叶植物而言,全光照和较强光照、较低的生长温度、适度的土壤和大气干旱以及低pH值介质条件有利于花色素苷的合成、稳定和积累;而外源物质中,可溶糖、柠檬酸等有机物能促进花色素苷的合成和积累,乙烯、脱落酸(ABA)、金雀异黄素(GNT)、5.氨基乙酰丙酸(ALA)和茉莉酸(JA)等生长调节物质具有促进花色素苷合成和积累的作用,铜、钾、钙等矿质元素可促进花色素苷的合成和积累.论文还分析归纳了该领域尚待解决的问题(如外界因子对不同种类的花色素苷合成及比例变化的影响有何不同?),并指出了今后的研究方向,重点应明确环境因子是如何影响花色素苷的代谢路径以及不同种类植物中的花色素苷对外界影响因子响应机制的差异等.     

2003—2010年中国对流层CO2时空分布研究

利用2003年到2010年的美国宇航局（National Aeronautics and Space Administration,NASA）的AIRS（Atmosphere InfraRed Sounder）官方反演的对流层中层（500 hPa）左右一段气柱内的CO2体积混合比产品分析中国地区对流层的CO2体积分数分布时空变化特征。所用数据是对AIRS L3产品2°×2.5°网格数据进行处理分析得到。经过对这8年的观测数据（2003年1月—2010年12月）的数据分析研究发现：中国地区平均CO2的体积分数在空间分布上极不平衡,总体高值集中于北部。CO2对流层中层的高值区集中在35°—45°N,形成东北平原、内蒙古中西部地区、塔克拉玛干沙漠和塔里木盆地4个高值中心,而云南地区和西藏南部上空的CO2值偏低。与中国地区8年平均CO2体积分数变化特征大体一致,每月（8年平均值）分布趋势也呈北部地区和东部地区高而南方体积分数值相对低的特征。CO2月平均体积分数的最高值一般出现在每年的4月或者5月,而每年的最低值则出现在每年的1月。对流层中层CO2体积分数呈现明显季节变化,总体上来说,从2003年到2010年这8年中,平均春、夏两季对流层中CO2含量较高,而秋、冬季CO2低于春夏两季。