Control effects of pε and pH on the generation and stability of chlorine dioxide

IntroductionDuetotheformationofsomepotentiallyhazardousby productsfromchlorinedisinfectionindrinkingwater,chlorinedioxide(ClO2 ) ,asanalternativedisinfectantandaneffectiveoxidant,formedfewerhalogenatedDBPsthanchlorine(Richardson ,1 994;2 0 0 0 ;Bryant,1 992 ) .InvestigationsofthegenerationandstabilityofClO2 havealreadypromoteditsapplication .However,previousstudiespaynoattentiontothefactorofelectronactivity (pε)thatactuallyaffectsthegenerationandstabilityofClO2 Theignoranceofpεappearan…     

Extraction of copper ions by supercritical carbon dioxide

ＩｎｔｒｏｄｕｃｔｉｏｎＣｏｍｐｌｅｘａｔｉｏｎｃｏｍｂｉｎｅｄｗｉｔｈｓｏｌｖｅｎｔｅｘｔｒａｃｔｉｏｎｈａｓｂｅｅｎｕｓｅｄｔｏｅｘｔｒａｃｔｍｅｔａｌｉｏｎｓｆｒｏｍｓｏｌｉｄｍａｔｒｉｘｓｕｃｈａｓｓｏｉｌｓａｎｄｓｅｄｉｍｅｎｔｓ(Ｍｉｎｃｚｅｗｓｋｉ,1 982 ;Ａｌｆａｓｓｉ,1 992 ) .Ｔｈｅｓｅｓｏｌｖｅｎｔｅｘｔｒａｃｔｉｏｎｐｒｏｃｅｄｕｒｅｓｈｏｗｅｖｅｒａｒｅｕｓｕａｌｌｙｔｉｍｅａｎｄｌａｂｏｒ ｉｎｔｅｎｓｉｖｅ.Ｉｎａｄｄｉｔｉｏｎｓｏｌｖｅｎｔｅｘｔｒａｃｔｉｏｎｒｅｑｕｉ…     

Removal of benzene homologous compounds with chlorine dioxide

Ｒｅｍｏｖａｌｏｆｂｅｎｚｅｎｅｈｏｍｏｌｏｇｏｕｓｃｏｍｐｏｕｎｄｓｗｉｔｈｃｈｌｏｒｉｎｅｄｉｏｘｉｄｅ￥ＣｈｅｎＨｕｉ；ＷｅｉＤｏｎｇｂｉｎ（ＣｈｅｍｉｓｔｒｙＤｅｐａｒｔｍｅｎｔ，ＮｏｒｔｈｗｅｓｔＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｌａｎｚｈ...     

Effects of sulfur dioxide on growth,gas exchange rate and leaf sulfur content of massion pine seedlings

Ｅｆｆｅｃｔｓｏｆｓｕｌｆｕｒｄｉｏｘｉｄｅｏｎｇｒｏｗｔｈ，ｇａｓｅｘｃｈａｎｇｅｒａｔｅａｎｄｌｅａｆｓｕｌｆｕｒｃｏｎｔｅｎｔｏｆｍａｓｓｉｏｎｐｉｎｅｓｅｅｄｌｉｎｇｓＹａｎｇＬｉａｎｇＵｎｉｔｅｄＧｒａｄｕａｔｅＳｃｈｏｏｌ，ＴｏｋｙｏＵｎ...     

Decomposition and decoupling analysis of carbon dioxide emissions in African countries during 1984‒2014

The potential for mitigating climate change is growing worldwide, with an increasing emphasis on reducing CO₂ emissions and minimising the impact on the environment. African continent is faced with the unique challenge of climate change whilst coping with extreme poverty, explosive population growth and economic difficulties. CO₂ emission patterns in Africa are analysed in this study to understand primary CO₂ sources and underlying driving forces further. Data are examined using gravity model, logarithmic mean divisia index and Tapio's decoupling indicator of CO₂ emissions from economic development in 20 selected African countries during 1984?2014. Results reveal that CO₂ emissions increased by 2.11% (453.73 million ton) over the research period. Gravity centre for African CO₂ emissions had shifted towards the northeast direction. Population and economic growth were primary driving forces of CO₂ emissions. Industrial structure and emission efficiency effects partially offset the growth of CO₂ emissions. The economic growth effect was an offset factor in central African countries and Zimbabwe due to political instability and economic mismanagement. Industrial structure and emission efficiency were insufficient to decouple economic development from CO₂ emissions and relieve the pressure of population explosion on CO₂ emissions in Africa. Thus, future efforts in reducing CO₂ emissions should focus on scale-up energy-efficient technologies, renewable energy update, emission pricing and long-term green development towards sustainable development goals by 2030.     

Control strategy for sulfur dioxide and acid rain pollution inChinaa

Several factors, namely, coal-dominated primary energy mix, extensive economic development mode, inefficient energy utilization, end the imperfect environmental regulations, result in the serious urban sulfur dioxide pollution end large-scale sulfatetype acid precipitation in China. In 1995, China's sulfur dioxide emissions reached 23.70 Mt, and the areas affected by acid rain accounted for 40% of the territory. Chinese government accords considerable importance to the sulfur dioxide end acid rain contamination. New sets of environmental friendly policies have been promulgated. But enforcement of laws and regulations on SO2 emissions need to be further improved and broadened, especially those respond to market conditions. This paper focuses particular attention on the analysis of strategy, policies, and national actions which had or should be taken against sulfur dioxide emissions nationwide to achieve the environmental targets, on the basis of which gives the technical options in future.     

Progress in carbon dioxide separation and capture： A review

This article reviews the progress made in CO2 separation and capture research and engineering. Various technologies, such as absorption, adsorption, and membrane separation, are thoroughly discussed. New concepts such as chemical-looping combustion and hydrate-based separation are also introduced briefly. Future directions are suggested. Sequestration methods, such as forestation, ocean fertilization and mineral carbonation techniques are also covered. Underground injection and direct ocean dump are not covered.     

Atmospheric carbon dioxide and sulphur dioxide on an urban/rural transect—II. Measurements along the transect

Carbon dioxide and sulphur dioxide were measured on a transect between urban Nottingham and a rural area 15 km to the south-west. A method was developed for taking almost simultaneous measurements at nine points along the transect. 125 sets of measurements were made between December 1984 and July 1985. During the winter months small trends of increasing CO₂ and SO₂ towards the city were observed both at night and during the day. In the summer, this trend was reversed at night for CO₂ which was increasingly controlled by the diurnal photosynthesis/respiration cycle.     

Carbon dioxide adsorption and cycloaddition reaction of epoxides using chitosan–graphene oxide nanocomposite as a catalyst

One of today's major challenges is to provide green materials for a cleaner environment. We have conducted studies on carbon dioxide(CO2) adsorption and conversion to valuable products by an ecofriendly approach based in chitosan/graphene oxide(CSGO) nanocomposite film. Rheological behavior indicates that the CSGO has a better solvation property than the pure chitosan. An adsorption capacity of 1.0152 mmol CO_2/g of CSGO nanocomposite at4.6 bar was observed. The catalytic behavior of the CSGO nanocomposite in the presence of tetra-n-butylammonium iodide(n-Bu4 NI) as co-catalyst was evaluated for the cycloaddition of CO_2 to epoxides, to give cyclic carbonates, in the absence of any solvent. These results strongly suggest that the CSGO nanocomposite may open new vistas towards the development of ecofriendly material for catalytic conversion and adsorption of CO_2 on industrial scale.     

Control strategy for sulfur dioxide and acid rain pollution in China

Ｃｈｉｎａ′ｓｅｃｏｎｏｍｙｈａｓｅｘｐａｎｄｅｄａｔａｎａｖｅｒａｇｅｏｆｏｖｅｒ 9%ｅａｃｈｙｅａｒｆｏｒｔｈｅｐａｓｔｔｗｏｄｅｃａｄｅｓ.Ｃｏｎｔｉｎｕｉｎｇｔｈｉｓｒａｐｉｄｅｃｏｎｏｍｉｃ ｇｒｏｗｔｈｗｈｉｌｅｓｉｍｕｌｔａｎｅｏｕｓｌｙｉｍｐｌｅｍｅｎｔｉｎｇｅｆｆｅｃｔｉｖｅ ｐｏｌｌｕｔｉｏｎｃｏｎｔｒｏｌｓｔｒａｔｅｇｙｐｒｅｓｅｎｔｓＣｈｉｎａｗｉｔｈａｎｕｒｇｅｎｔｃｈａｌｌｅｎｇｅ .1　Ｃｕｒｒｅｎｔｓｔａｔｕｓｏｆｓｕｌｆｕｒｄｉｏｘｉｄｅａｎｄａｃｉｄｒａｉｎｐｏｌｌ…     

Treatment of manganese wastewater from titanium dioxide plant using complex phosphate

ＩｎｔｒｏｄｕｃｔｉｏｎＵｓｉｎｇｃｏｍｐｌｅｘｐｈｏｓｐｈａｔｅｔｏｔｒｅａｔｍａｎｇａｎｅｓｅｗａｓｔｅｗａｔｅｒｆｒｏｍｔｉｔａｎｉｕｍｄｉｏｘｉｄｅｐｌａｎｔｗａｓｐｒｅｓｅｎｔｅｄｉｎｔｈｉｓｐａｐｅｒ.Ｃｏｍｐａｒｉｎｇｗｉｔｈｏｔｈｅｒ?..     

Atmospheric carbon dioxide and sulphur dioxide on an urban/rural transect—I. Continuous measurements at the transect ends

Carbon dioxide and sulphur dioxide concentrations have been measured on a transect between urban Nottingham and a rural area 15 km to the south-west. In Part I, the results of fixed point measurements at the ends of the transect are described. Seasonal averages showed no significant difference for CO₂ or SO₂ concentrations in the summer; in winter the mean CO₂ concentration in the city centre was 5 μl ℓ⁻¹ larger than the rural mean. These figures conceal large differences in the diurnal variation between the two sites.     

Field carbon dioxide flux density

A synchronous observation of field microclimate parameters using a method of infrared analysis with additional air channel and circuit systems is introduced in this paper．The concentration and the flux density of CO₂ in wheat field and maize field were studied．The data in several years were calculated using aerodynamic method and satisfactory results were obtained．Relation of CO2 flux to global radiation，net radiation，turbulent exchange coefficient and wind velocity were also analyzed and discussed integrated with practical aspects．     

Inactivation effect of pressurized carbon dioxide on bacteriophage Qβ and ΦX174 as a novel disinfectant for water treatment

The inactivation effects of pressurized CO2 against bacteriophage Qβ and ΦX174 were investigated under the pressure of 0.3–0.9 MPa, initial concentration of 107–109PFU/mL, and temperature of17.8°C–27.2°C. The optimum conditions were found to be 0.7 MPa and an exposure time of 25 min. Under identical treatment conditions, a greater than 3.3-log reduction in bacteriophage Qβ was achieved by CO2, while a nearly 3.0 log reduction was observed for phage ΦX174. The viricidal effects of N2O(an inactivation gas with similar characteristics to CO2), normal acid(HCl), and CO2 treatment with phosphate buffered saline affirmed the chemical nature of CO2 treatment. The pumping cycle, depressurization rate, and release of intracellular substances caused by CO2 were its viricidal mechanisms. The results indicate that CO2 has the potential for use as a disinfectant without forming disinfection by-products.     

Global warming related carbon dioxide abatement proposals

The relationship between man-made CO2 emission and atmospheric CO2 concentration has been established. The factors that affect CO2 reduction allotment and the impacts on future energy demand and supply were discussed, in order to help energy policy makers both in developed countries and in developing countries for understanding the fundamental constraint on energy sector resulted from global warming related CO2 reduction, and hopefully in finding a common objective starting point to deal with global warming negotiation in energy sector, and to investigate the optimum stabilization goal and process acceptable to all sovereign countries that based on equity and applicability.     

The kinetic study for reduction of NO by CO over cobalt tetraphenylporphyrin supported on titanium dioxide

The catalytic reduction of nitric oxide by carbon monoxide over cobalt tetraphenylporphyrin supported on titanium dioxide (Co-TPP/TiO2) has been investigated. Co-TPP/TiO2 pretreated by evacuation at 270℃ exhibited a remarkable activity. The kinetic equation for the reduction of nitric oxide by carbon monoxide in the reaction temperature ranging from 80 to 150℃ (v=kPNO 0.56Pco 0.41) suggested that the reaction can be assumed to occur via a surface reaction of the Langmuir-Hinshelwood model between nitric oxide and carbon monoxide adsorbed on the central metal ion of Co-TPP. Experimental results indicated that the reduction of nitric oxide and formation of molecular nitrogen took place simultaneously during initial stage of the reaction. The apparent activation energy was calculated to be 30.8 kJ/mol.     

The influence of environmental factors on the carbon dioxide flux across the water–air interface of reservoirs in south-eastern Poland

Studies concerning the emission of carbon dioxide(CO_2) were carried out in 2009–2012 for six reservoirs located in four provinces of south-eastern Poland. The CO_2 flux across the water–air interface was measured using the "static chamber" method. The measured fluxes of CO_2(FCO_2) ranged from-30.64 to 183.78 mmol/m~2/day, and the average values varied in the range from-3.52 to 82.11 mmol/m2/day. In most of the cases, emission of CO_2 to the atmosphere was observed. The obtained values of CO_2 fluxes were comparable to values typical for other temperate reservoirs. Analysis of the influence of selected environmental factors on the FCO_2 showed that it depends on parameters characterizing both the sediments and surface water. The CO_2 flux at the water–air interface was positively correlated with parameters of bottom sediments such as porosity, content of organic carbon and total nitrogen; and negatively with p H value and δ~(13)C of organic carbon. In the case of the parameters characterizing surface water, positive dependences on the concentrations of nitrate and total nitrogen, and negative relationships with water temperature and chlorophyll a concentrations, were found.     

Enhanced removal of organics by permanganate preoxidation using tannic acid as a model compound – Role of in situ formed manganese dioxide

The effect of permanganate preoxidation on organic matter removal during the coagulation with aluminum chloride was investigated using tannic acid as a model compound. Results showed that a small amount of KMnO4 (0.75 mg/L) increased the removal efficiency of tannic acid up to 20%, as compared to the process of coagulation by aluminum chloride alone. The key factor enhancing the removal efficiency of tannic acid in preoxidation process was the in situ formation of a reductant manganese dioxide. The complexation model was used to describe the reaction between MnO2 and tannic acid. Under weak pH condition, tannic acid was difficult to be adsorbed by MnO2 due to the static electrical repulsive forces. The presence of Ca2+ served as a bridge to hold the negative charged MnO2 and tannic acid together, which could be a crucial factor influencing tannic acid adsorption by in-situ manganese dioxide.     

Three industries and wastewater and COD discharge of Beijing

Ｒｅｃｅｎｔｌｙ,ｗｉｔｈｔｈｅｓｗｉｆｔｄｅｖｅｌｏｐｍｅｎｔｏｆｅｃｏｎｏｍｙａｎｄｔｈｅｉｍｐｒｏｖｅｍｅｎｔｏｆｐｅｏｐｌｅ′ｓｌｉｖｉｎｇｓｔａｎｄａｒｄ ,ｔｈｅｗａｔｅｒｕｓｅａｍｏｕｎｔａｎｄｗａｓｔｅｗａｔｅｒｄｉｓｃｈａｒｇｅｂｅｃｏｍｅｂｉｇｇｅｒａｎｄｂｉｇｇｅｒ,ａｎｄｔｈｅｗａｔｅｒｑｕａｌｉｔｙｉｓｇｅｔｔｉｎｇｗｏｒｓｅａｎｄｗｏｒｓｅ .Ｓｏｉｌａｎｄａｇｒｉｃｕｌｔｕｒａｌｐｒｏｄｕｃｔｓｈａｖｅｂｅｅｎｐｏｌｌｕｔｅｄｂｙｔｈｅｗａｓｔｅｗａｔｅｒ,ａｎｄｐｅｏｐ…     

Mechanics Principle and Engineering Application of Split Layer and Bed Separation of Mining Overburden

<正>To control land surface subsidence caused the underground mineral exploitation and the catastrophic phenomena such as serious damage of buildings, waterbodies, cultivated lands, railways, bridges caused by land subsidence, bed separation grouting technology of overburden is put forward. To provide theoretical support for the technology, the characteristics and the mechanics mechanism of mining overburden from layer-split to formation of bed separation are studied. On the basis of elastic sheet board theory, calculation formula of rock sheet deflection is presented, and the mechanics criteria of the separation formation and the calculation formula of bed separation volume are set up. Finally, the applications and technics of bed separation grout technology of mining overburden to control land subsidence in china are introduced.