Enzymatic degradation of low-rank coals by a cell-free enzymatic system from Coriolus versicolor

An extracellular fraction from the lignin degrading white-rot fungus, Coriolus versicolor, can biosolubilize leonardite and pretreated lignites in vitro. Leonardite is often found as an overburden to lignite deposits, and is related to humic acid, and is more oxidized than lignites. Extracts from certain fungi such as C. versicolor solubilize leonardite. The biosolubilization activity is at least in part enzymatic in nature. A protein which is at least partly responsible for the solubilization effect has been substantially purified and concentrated by ultrafiltration and ion-exchange chromatography from the broth of an agitated submerged culture of C. versicolor grown in a defined medium. An in vitro coal biosolubilization assay was used to establish the effects of various physical and chemical factors affecting enzyme activity, including temperature and the salt and buffer composition of the reaction mixture. Some initial studies on the mechanism of the enzymatic leonardite biosolubilization reaction are described.     

Assessing the current practice and policy with recommendations for emission control strategy for coal‐fired thermal power plants under Indian regulatory framework emphasizing the roles of R&D

On December 7, 2015, the Ministry of Environment, Forest and Climate Change (MoEFCC), Government of India (GoI), promulgated stack emission standards for sulfur dioxide (SO₂), oxides of nitrogen (NO_x), and mercury (Hg) from coal‐fired thermal power plants (TPPs). These standards were promulgated in addition to tightening the emission standard for particulate matter. Thus far, the GoI and a non‐governmental organization (NGO) have recommended the use of limestone‐based flue‐gas desulfurization (FGD) technology for removing only SO₂ emissions, which would then require the application of additional technologies to remove the other regulated pollutants. A single technology, such as the Multi‐pollutants Control Technology (MPCT), which was recently developed elsewhere in the world and can remove all of the pollutants from the TPP, could be more economical than introducing separate technologies for the removal of each pollutant. Furthermore, unlike the limestone‐based FGD technology, which generates carbon dioxide (CO₂) during the desulfurization process, the MPCT does not increase power plant CO₂ emissions. Water consumption is also lower in MPCT than with the limestone‐based FGD technology. Thus, MPCT offers a lower carbon footprint as well as a lower water footprint than the limestone‐based FGD technology in accordance with the United Nations Environmental Programme's Sustainable Development Goals. In light of these observations, this article aims to assess current practices and policies and offers policy recommendations for Indian TPPs with the goal of providing a cogent technological solution that also strengthens the Decision Support System for the holistic protection of the Indian environment.     

Ultra-deep Desulfurization of Liquid Hydrocarbon Fuels: Chemistry and Process

Abstract

Recently, ultra-deep desulfurization of liquid hydrocarbon fuels is becoming very important worldwide not only because of the heightened interest for cleaner air and thus increasingly stringent environmental regulations for fuel sulfur content, but also because of the great need for making ultra-low-sulfur fuels used in hydrocarbon fuel process for fuel cell applications. This article is a selective review on chemistry and process concerning the ultra-deep desulfurization of liquid hydrocarbon fuels. The principles and problems for the existing hydrodesulfurization processes and the challenges, concepts, advantages, and disadvantages of various new approaches are discussed, including (1) sulfur compounds in liquid hydrocarbon fuels; (2) Reactivity and mechanistic aspect of various sulfur compounds; (3) Challenges in ultra-deep desulfurization processes; (4) Approaches to ultra-deep desulfurization process.     

高含硫化氢原油除硫技术研究与应用

针对新疆油田分公司采油一厂车89井区高含硫的问题,分别对硫化氢成因、转化机理及除硫方式进行研究,开展了化学除硫工艺技术、负压闪蒸除硫工艺技术以及催化曝气除硫工艺技术现场试验。试验结果表明:采用负压闪蒸除硫工艺、催化曝气除硫工艺及化学除硫工艺(HCS-4除硫剂加药浓度约1×104 mg/L、作用80s)处理后,可将车89井区原油中硫化氢浓度降至安全阈限值15mg/m3以下。     

硫化废气污泥活性炭净化处理技术研究

以污泥厂剩余活性污泥作为原料,采用KOH为活化剂制备污泥活性炭,探讨了活化温度及时间、热解温度、洗涤温度及方式在污泥活性炭制备过程中的最佳工艺条件。以品红吸附量及产率作为污泥活性炭的考察指标,采用单因素实验筛选出了制备污泥活性炭的最佳工艺条件,并对污泥活性炭脱硫剂的脱硫性能进行了实验研究。实验研究结果显示,烟气中O2、水蒸气含量的多少及脱硫温度的高低会影响污泥活性炭脱硫剂的脱硫性能。     

Conflicting energy and environmental policies: The portsmouth oil refinery

This case study presents the series of decision-making processes surrounding a current environmental issue—the Portsmouth oil refinery in Virginia. Crude oil must be refined before it can be used as fuel. Additionally, some oil must be desulfurized for use other than as gasoline. In 1977, the nation imported about one million barrels of oil a day. Although the US Department of Energy has emphasized the critical need for greater east coast refinery capability, the east coast is to supply only 25% of its refined oil needs. In the same year, the east coast met its demands for petroleum products from three sources: (a) refinery production, 22.7%, (b) product imports, 28.0%, and (c) products from the Gulf Coast, 49.3%.¹ The energy program after the Arab oil embargo has an objective of encouraging the construction of oil refineries and petrochemical plants in the United States rather than abroad. The tariff is higher on imports of refined oil products than of crude oil, and new refineries are allowed to import a large proportion of their requirements tarifffree.The US federal government does not directly regulate the locations for oil refineries or methods of desulfurization. The oil import program, however, does influence decisions concerning location of desulfurization facilities and refineries, and air and water pollution standards affect methods of refining, besides making desulfurization necessary.The opinions expressed in this article are those of the author and do not necessarily reflect those of the United States Department of Defense.     

改性活性炭脱除硫化氢工艺参数研究

针对改性活性炭脱除硫化氢过程,研究了空速、温度、原料气浓度、颗粒分布孔径4个主要工艺参数对脱硫效率的影响。结果表明:空速在1 500～4 200h-1时穿透硫容随着空速的降低而增加,当空速继续降低为1 200h-1时穿透硫容基本不变;当0～40℃时,随着温度的升高,穿透时间增加,脱硫效率提高,当温度超过40℃时,随着温度继续升高脱硫效率降低;相同空速下原料气硫化氢浓度变化只改变穿透时间;改性活性炭脱硫剂发挥脱硫作用的微孔结构范围是1～5nm。     

Reusing pretreated desulfurization slag to improve clinkerization and clinker grindability for energy conservation in cement manufacture

The purpose of this study was to combine the physical pretreatments of grinding, sieving, and magnetic-separation processes to reclaim iron-rich materials from the desulfurization slag, and to use the remainder for cement clinker production. The iron-rich materials can be separated out efficiently by grinding for 30 min and sieving with a 0.3 mm mesh. The non-magnetic fraction of the particles smaller than 0.3 mm was in the majority, and proved to be suitable for use as a cement raw material. The raw mixes prepared with a pretreated desulfurization slag had a relatively high reactivity, and the temperature at which alite forms was significantly reduced during the clinkerization process. The clinkers produced with 10% desulfurization slag had a high level of alite and good grindability. Generally, the improvements in clinkerization and clinker grindability are beneficial to energy conservation in cement manufacture.     

氮气搅拌下高硫铝土矿电解脱硫研究

采用氮气搅拌的方法,强化高硫铝土矿电解脱硫过程,考察了电解液配比、电流密度、气流速度等因素对脱硫率的影响。研究表明：脱硫率随电解液中NaCl含量增加而增加;电解脱硫率随着NaOH浓度和电流密度先升高后下降;增加气体流速能够显著提高电解脱硫率。基于电解脱硫特点,提出了铝土矿电解脱硫工艺与现有氧化铝生产的衔接方式。     

Possible Utilization of Silica Gel Sludge for the Removal of Phenol from Aqueous Solutions: Laboratory Studies

This paper discusses the adsorption capacity of silica gel sludge for phenol removal from aqueous solution. Kinetic experiments showed that phenol adsorption was completed after 2 h. Adsorption isotherms were measured for phenol from aqueous solution onto silica gel sludge under various pHs and temperatures. Results showed that the adsorption capacities for phenol was increased as pH decreased from 6.5 to 2. Temperature also was found to affect the adsorption isotherm. As temperature increases from 30 to 50°C, the adsorption capacity increases. The adsorption equilibrium of phenol on silica gel sludge was described by the linear Freundlich and Langmuir models. Furthermore, results showed that the isotherm parameters fit both linearized Langmuir and Freundlich adsorption isotherms. The Freundlich and Langmuir parameters at optimum pH was found as K _f=2.89, 1/n=0.23 and K _d=22.0, q _m=7.98, respectively. Whereas, for those at optimum temperature it was observed as K _f=2.87, 1/n=0.16 and K _d=20.93, q _m=7.91, respectively.     

旋转喷雾干燥法(SDA)脱硫工艺系统的应用研究

本文介绍了旋转喷雾干燥法（SDA）脱硫工艺的基本原理、化学过程、主要设备、控制、脱硫副产物、系统运行与维护等,并与石灰石/石膏湿法脱硫工艺、烟气循环流化床工艺进行了比较,给出了脱硫系统投资及运行费用的经济比较。还对SDA脱硫工艺在国内应用中存在的问题进行了探讨。     

Experimental investigation of groundwater contamination by surface sources: Determination of adsorption capacity,diffusion, and sorption potential of selected anions in different soils

The present study investigated the fate and transport of two significant anions through soil to explore their potential as groundwater contaminants. The retention properties of chloride and sulfate in soils having several significantly different characteristics (soil‐1 and soil‐2) were determined using adsorption test and adsorption‐diffusion column experiments. The maximum adsorption capacity of chloride was 3.7 and 1.16 mg/g, respectively, in soil‐1 and soil‐2, with organic matter (OM) content of 3.92% and 4.69%, respectively. The sulfate adsorption obtained was 24.09% and 13.83%, respectively, in the two soils. The anions exhibited monolayer adsorption in the soils with replacement of hydroxyl ions from soils as the major mechanism of adsorption. On the other hand, the adsorption capacities obtained from the adsorption‐diffusion column experiment were about 100 times lower compared to that of the column tests of both of the soils. The maximum adsorption capacity of chloride was 0.03 mg/g and 0.01 mg/g, respectively, in soil‐1 and soil‐2, whereas that of sulfate was 0.04 mg/g and 0.03 mg/g. The empirical relation for depth of penetration (d) from a known spillage onto the soil surface was determined as a function of sorption capacity (S) and initial anion concentration (C) as d = 0.0073e^(?57S)C and d = 0.0038e^(?35S)C for chloride and sulfate, respectively.     

Effect of aspect on the structure of some natural stands of Abies pindrow in Himalayan moist temperate forest

The effects of aspect, altitude, and slope have been observed on the moist temperate forests of Abies pindrow Spach in the Garhwal Himalaya, India. Four aspects, namely, north-east, north-west, south-east and south-west, have been studied to understand the growth behaviour of A. pindrow at varying altitudes. The total basal cover was found to be highest (5099.6 cm²/100 m²) on the north-east facing slopes, and lowest (3092.7 cm²/100 m²) on the south-east facing slopes. The A. pindrow was found to be associated with Quercus semecarpifolia as a main companion species on all the faces, whereas, Lyonia ovalifolia, was associated only on the west facing slopes.     

Recent Changes in the Riparian Forest of a Large Regulated Mediterranean River: Implications for Management

The structure of the floodplain forests of the Middle Ebro River (NE Spain) was examined at patch and landscape scales along a three-step chronosequence defined according to the extent of flow regulation-induced hydrogeomorphic changes, with the ultimate purpose of producing baseline information to guide through management and restoration plans. At patch scale, a total of 6,891 stems within 39 plots were registered for species, diameter and health status. The stem density, size class distribution, canopy dieback and mortality were further compared by means of non-parametric tests. At landscape scale, the temporal evolution of the area occupied by forest stands of different ages in the floodplain along the chronosequence was evaluated using four sets of aerial photographs dated in 1927, 1957, 1981 and 2003. The within-patch structure of pioneer forests (<25–30 years old) was characterized by dense and healthy populations of pioneer species (Populus nigra, Salix alba and Tamarix spp.), but the area occupied by these forest types has progressively decreased (up to 37%) since the intensification of river regulation (ca. 1957). In contrast, non-pioneer forests (>25–30 years old) were characterized by declining and sparse P. nigra–S. alba–Tamarix spp. stands, where late-seral species such as Ulmus minor and Fraxinus angustifolia were frequent, but only as small-size stems. At landscape scale, these type of senescent forests have doubled their surface after river regulation was intensified. Populus alba only appeared in the oldest plots recorded (colonized before 1957), suggesting sexual regeneration failure during the last five decades, but usually as healthy and dense stands. Based on these findings, measures principally aimed at recovering some hydrogeomorphic dynamism are recommended to guarantee the self-sustainability of the floodplain forest ecosystem.     

Rainfall Interception Based on Indirect Methods: A Case Study in Temperate Forests in Oaxaca,Mexico

Rainfall interception represents the amount of water trapped in natural cover that is not drained directly to the ground. Intercepted rainfall may evaporate after a rain event, making it one of the main drivers of water balance and hydrologic regionalization. This process can be affected by factors such as climate, altitude, vegetation type, and topography. Here is a simple method of calculating rainfall interception in temperate forests using in Santa Maria Yavesia, Oaxaca, and Mexico as an illustrative study area. We used two rain gauges to measure net precipitation (N_p) under the canopy at each study site and one gauge outside the canopy to obtain gross precipitation (G_p). Throughfall (T_h) was indirectly measured using hemispherical photographs. Rainfall interception was obtained through a combination T_h and G_p and N_p. The mean rainfall interception was 50.6% in the Abies forests, 23%–40% in the coniferous‐mixed forests, and 27.4% in the broad‐leaved forests. We classified rainfall events by intensity to determine the effect of canopy structure and precipitation and found that 75% of the events were weak events, 24% were moderate events, and 1% were strong events. In addition, we found that rainfall interception was lower when the intensity of precipitation was higher. Our method can be replicated in different ecosystems worldwide as a tool for assessing the influence of rainfall interception in terms of ecological services.     

Effect of Agave attenuata extracts on detoxification enzymes of Biomphlaria alexandrina

The toxicity and rising costs of synthetic molluscicides have led to interest in compounds derived from locally growing plants that can be used as molluscicides. The aim of the present work was to study the effect of extracts of some Egyptian plants having lethal effect on snails of medical importance (Biomphlaria alexandrina) as well as on antioxidant and glutathione detoxification enzymes. Ethanolic extracts of locally growing plants Agave attenuata, Agave sislana, Phytolaca dodecandra and Euphorbia spllendens were applied as a contact poison to B. alexandrina, the intermediate host of Schistosoma mansoni. The LC₅₀ of A. attenuata, A. sislana, P. dodecandra and E. spllendens are 82, 101, 98 and 98 mg/L, respectively. Glutathione and the enzymes involved in protection of the snail from reactive oxygen species namely, glutathione peroxidase, glutathione reductase, glutathione S-transferase, catalase, gamma glutamyl transferase increased in the survival snails exposed to high concentrations of A. attenuata. Glucose-6-phosphate dehydrogenase indirectly affecting glutathione reductase and the oxidation, reduction of glutathione significantly decreased in snails exposed to A. attenuata extracts. Superoxide dismutase level tend to decrease in snails exposed to A. attenuata of action. In conclusion A. attenuata is preferable when compared with synthetic molluscicides. The enzymes involved directly or indirectly in protection mechanism of the snail against A. attenuata are mainly responsible for snails survival.     

Abundance of Jackfruit (<Emphasis Type="Italic">Artocarpus heterophyllus</Emphasis>) Affects Group Characteristics and Use of Space by Golden-Headed Lion Tamarins (<Emphasis Type="Italic">Leontopithecus chrysomelas</Emphasis>) in <Emphasis Type="Italic">Cabruca</Emphasis> Agroforest

Cabruca is an agroforest of cacao trees shaded by native forest trees. It is the predominant vegetation type throughout eastern part of the range of the golden-headed lion tamarins, Leontopithecus chrysomelas, an endangered primate endemic to Atlantic Forest. Understanding how lion tamarins use this agroforest is a conservation priority. To address this question, we documented the diet, home range size, group sizes and composition, density, number of litters and body condition of lion tamarins living in cabruca, and other habitats. Jackfruit, Artocarpus heterophyllus, was the most used species used by lion tamarins in cabruca and was widely available and used throughout the year. In cabruca, home range size was the smallest (22–28 ha) and density of lion tamarins was the highest (1.7 ind/ha) reported for the species. Group size averaged 7.4 individuals and was not significantly different among the vegetation types. In cabruca, groups produced one or two litters a year, and all litters were twins. Adult males in cabruca were significantly heavier than males in primary forest. Our study is the first to demonstrate that breeding groups of golden-headed lion tamarins can survive and reproduce entirely within cabruca agroforest. Jackfruit proved to be a keystone resource for lion tamarins in cabruca, and bromeliads were important as an animal prey foraging microhabitat. In cases where cabruca contains concentrated resources, such as jackfruit and bromeliads, lion tamarins may not only survive and reproduce but may fare better than in other forest types, at least for body condition and reproduction.     

EFFECTS OF CHELATED IRON ON THE GROWTH OF TWO SPECIES OF VALLISNERIA1

ABSTRACT: Iron, added as (Fe-EDTA)^-, was found stimulatory to V. spiralis at a concentration of 0.05 ppm. (Fe-EDTA)^- had no effect upon growth of V. neotropicalis as measured by changes in dissolved oxygen and dry weight. Results are compared with those derived from similar studies with Hydrilla verticillata and Egeria densa. The implications of lake drawdown and aeration are discussed.     

活性炭纤维复合材料的脱硫性能

本实验以粘胶基活性炭纤维和酚醛树脂复合，制备出了一种可用于烟气脱硫的活性炭纤维复合材料（ACFM），考察了制备工艺条件对脱硫性能和比表面积的影响，测试其在填充床的压降。结果表明：粘结剂用量、炭化及活化条件对样品的脱硫性能和比表面积有较大的影响；与其他活性炭材料相比ACFM压降相对较低，只有活性炭纤维的1／20。     

Spatio-Temporal Variability of Soil Respiration of Forest Ecosystems in China: Influencing Factors and Evaluation Model

Understanding the influencing factors of the spatio-temporal variability of soil respiration (R _s) across different ecosystems as well as the evaluation model of R _s is critical to the accurate prediction of future changes in carbon exchange between ecosystems and the atmosphere. R _s data from 50 different forest ecosystems in China were summarized and the influences of environmental variables on the spatio-temporal variability of R _s were analyzed. The results showed that both the mean annual air temperature and precipitation were weakly correlated with annual R _s, but strongly with soil carbon turnover rate. R _s at a reference temperature of 0°C was only significantly and positively correlated with soil organic carbon (SOC) density at a depth of 20 cm. We tested a global-scale R _s model which predicted monthly mean R _s (R _s,monthly) from air temperature and precipitation. Both the original model and the reparameterized model poorly explained the monthly variability of R _s and failed to capture the inter-site variability of R _s. However, the residual of R _s,monthly was strongly correlated with SOC density. Thus, a modified empirical model (TPS model) was proposed, which included SOC density as an additional predictor of R _s. The TPS model explained monthly and inter-site variability of R _s for 56% and 25%, respectively. Moreover, the simulated annual R _s of TPS model was significantly correlated with the measured value. The TPS model driven by three variables easy to be obtained provides a new tool for R _s prediction, although a site-specific calibration is needed for using at a different region.