50 research outputs found
Operating conditions-induced changes in product yield and characteristics during thermal-conversion of peanut shell to biochar in relation to economic analysis
No full textThe influences of pyrolysis conditions on the products yield distribution and physico-chemical characteristics of biochar derived from peanut shell in a fixed-bed reactor were investigated in this study. The pyrolysis conditions included the pyrolysis temperature (300-700 degrees C), retention time (15-90 min), heating rate (1-10 degrees C min(-1)), gas flow rate (20-200 mL min(-1)) and feedstock particle size (<0.075, 0.075 0.150, 0.150-0.300 and 0.300-2.00 mm). Various analytical techniques were used to characterize the biochar for ultimate and proximate analyses, higher heating value (23.99-30.44 MJ kg(-1)), pH (8.11 -12.89), electrical conductivity (22.78-34.44 mS cm(-1)), surface functional groups (acidic, carboxylic and basic groups), Fourier transform infrared spectroscopy analysis, pore volume (0.055-1.241 cm(3) g(-1)) and specific surface area (7.12-20.96 m(2) g(-1)). The results demonstrated that the temperature predominantly regulated the product yields distribution and characteristics of produced biochar. Furthermore, the heating rate considerably influenced the biochar proximate composition, micropore surface area and pore size. Particle size had significant influences on biochar surface porosity and bio-oil yield. The economic analysis of the pyrolysis system indicated its feasibility and superiority with a positive net present value of 12.07 x 10(6) USD after twenty-five years of operation. (C) 2018 Elsevier Ltd. All rights reserved
Independent Kurdish State in Middle East: An Upcoming Epicenter of Middle East Power Politics
No full textThe paper is an attempt to encompass the geo-political and geo-strategic fault lines which could put the region in a perpetual strategic dilemma leading to initiation of a strategic tug of war between the Middle Eastern Powers. The author has highlighted various pros and cons of establishment of an independent Kurdistan and its implications on the entire Middle Eastern Region. Moreover the author has analyzed various practical reasons behind the non-establishment of an independent state. Furthermore last part of paper focuses on the global and regional reactions on the establishment of new Kurd state followed by few policy options
Novel investigation of pyrolysis mechanisms and kinetics for functional groups in biomass matrix
No full textBiomass, as a renewable and sustainable energy resource, can be converted into environmentally friendly and practically valuable biofuels and chemical materials via pyrolysis. However, the process optimization and pyrolysis efficiency are restricted by the limited perception of the complicated mechanisms and kinetics for biomass pyrolysis. Here, to establish an in-depth mechanism model for biomass pyrolysis, we presented a novel investigation for the thermal evolutions and pyrolysis kinetics of the functional groups in peanut shell matrix by using in-situ Fourier transform infrared spectrometry (in-situ FTIR) and thermogravimetric analysis-Fourier transform infrared spectrometry-mass spectrometry (TG-FTIR-MS). The in-situ FTIR spectrum deconvolution for the solid matrix was innovatively introduced to identify and quantify the real-time evolution and thermal dynamics of the functional groups during peanut shell pyrolysis. The result for the first time proposed that the pyrolysis mechanisms of total OH at 20-380 degrees C, aliphatic C-H-n groups at 20-500 degrees C, C=O groups at 260-500 degrees C, and C-O groups at 300-500 degrees C were dominant by diffusion and order-based chemical reactions. The TG-FTIR-MS analysis was conducted for the online monitoring of the released volatiles and gases, the amounts of which were in the sequence of C=O > CO2 > aliphatic C-O-(H) > C-O-(C) in esters > aromatics > H2O > phenolic hydroxyl > aliphatic hydrocarbons > CO. The study established a novel methodology to evaluate the biomass pyrolysis mechanisms at the molecular level, which provided valuable information for developing advanced pyrolysis techniques on a large scale for sustainable ecosystem
Comparative Analysis of Pak-Indo Press Role toward Annexation of Special Status of Kashmir: From War to Peace Perspective
No full textIndo-Pak Conflict on the territory of Kashmir started with Pakistan’s released in August 1947. At that time all the states were given the choice of choosing India or Pakistan. The then princely states rulers had to make their option. There have been some preliminaries, they said when selecting both states; one is the geographical proximity and the one was for the public ambition. In October 1947, given the fact that Kashmir was predominantly Muslim state that opted for the state of Pakistan, while the Kashmir’s Maharaja chose India in support. This choice was perceived by the Pakistani government as fraudulent, unfair and entirely unrecognized judgement. Furthermore, the religious orientation of more Kashmiri inhabitants can be seen as another factor in this conflict (Qumber, Ishaque and Shah 2017). This study aims to explore framing from war to peace-journalism after the Indian attempt of August 5, 2019, to annex the special status of Kashmir, in two English elite newspapers i.e. Daily Dawn, a Pakistani newspaper and the other is Hindustan Times an Indian Newspaper. The study explores news stories on front page along with editorials of these newspapers to understand how these newspapers covered and framed the issue
Investigating the uptake and acquisition of potentially toxic elements in plants and health risks associated with the addition of fresh biowaste amendments to industrially contaminated soil
No full textSoil contamination by potentially toxic elements (PTEs), due to rapid industrialization and urbanization, is a serious environmental concern that has been threatening both the sustainability of various agroecosystems and human health. Efforts to investigate the bioavailability, transfer, and accumulation of PTEs in the soil-plant system and their possible health consequences have almost exclusively focused in the past studies. However, there is limited evidence for increased human exposure to PTEs through dietary intake of food crop grown on contaminated soil influenced by fresh biowaste amendments (FBAs). Here, we show that FBAs addition to soil markedly (p.01) intensified human exposure to PTEs through impacts on solubility, uptake, and bioaccumulation compared with the control. In general, the risk assessment performed indicated that the hazard index values for FBAs treatments were notably higher than that of control; however, these were shown to be less than the legal limit (<1). In addition, the lifetime risks of developing carcinogenicity from exposure to PTEs were far above the maximum regulatory limits (1.00E-06), indicating that remarkable (p.01) amount of PTEs was transferred to food with the addition of FBAs. Conclusively, these results suggest that the use of FBAs to contaminated soil aggravates health risks of PTEs through wheat consumption. Further studies, which incorporate the in vitro gastrointestinal bioaccessibility, should be conducted to heighten our understanding about PTEs exposure and the risks associated with FBAs addition to contaminated soil
Combustion characteristics and retention-emission of selenium during co-firing of torrefied biomass and its blends with high ash coal
No full textThe combustion characteristics, kinetic analysis and selenium retention-emission behavior during co-combustion of high ash coal (HAC) with pine wood (PW) biomass and torrefied pine wood (TPW) were investigated through a combination of thermogravimetric analysis (TGA) and laboratory-based circulating fluidized bed combustion experiment. Improved ignition behavior and thermal reactivity of HAC were observed through the addition of a suitable proportion of biomass and torrefied. During combustion of blends, higher values of relative enrichment factors in fly ash revealed the maximum content of condensing volatile selenium on fly ash particles, and depleted level in bottom ash. Selenium emission in blends decreased by the increasing ratio of both PW and TPW. Higher reductions in the total Se volatilization were found for HAC/TPW than individual HAC sample, recommending that TPW have the best potential of selenium retention. The interaction amongst selenium and fly ash particles may cause the retention of selenium
Enrichment and distribution of trace elements in Padhrar, Thar and Kotli coals from Pakistan: Comparison to coals from China with an emphasis on the elements distribution
No full textThis paper reports the mineralogical and geochemical compositions of the Padhrar (salt-range), Thar (Block Nos. 3 and 5) and Kotli coals. The coal investigated in this study is lignite to sub-bituminous coal, with a broad range of ash yields, volatile matter content and sulfur contents. The mineralogical characteristic, major and trace elements were determined by X-ray diffraction, inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry, respectively. The mineral assemblages, sulfur contents, ash yields, and (CaO + MgO + Fe2O3)/(SiO2+ Al2O3) ratio varied significantly in the coal, which is attributed mainly to variation in the depositional environment. Pyritic sulfur is the main form of sulfur in the coals from Padhrar, Kotli and Thar coalfield. The minerals in the studied coals are dominated by quartz, pyrite, kaolinite, illite, along with calcite, feldspar, siderite, montmorillonite and gypsum. Sixteen trace elements, including Li, Be, B, Ti, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, As, Rb, Sr, and Ba and five major elements P, Ca, Al, Fe, and Si, were investigated in this study. The trace element concentrations show variety within the coal seams in the Thar coals and the affinities vary among locations. The concentration of Sr, Ti, Zn, Li, Ni, Cu, Sc, As, Be, and B in the present study are within the range of average Chinese coal values, with the exception of V, Cr, Fe, P, and Rb. On the other hand, compared with world coals, the studied coals have higher contents of B, Cr, Li, Fe, V, Rb, P, and Sc. Based on statistical analyses, most of the trace elements, show an affinity to ash yield and possible association with pyrite, kaolinite, and calcite
Investigating the biochar effects on C-mineralization and sequestration of carbon in soil compared with conventional amendments using the stable isotope (delta C-13) approach
No full textBiomass-derived black carbon (biochar) is considered to be an effective tool to mitigate global warming by long-term C-sequestration in soil and to influence C-mineralization via priming effects. However, the underlying mechanism of biochar (BC) priming relative to conventional biowaste (BW) amendments remains uncertain. Here, we used a stable carbon isotope (delta C-13) approach to estimate the possible biochar effects on native soil C-mineralization compared with various BW additions and potential carbon sequestration. The results show that immediately after application, BC suppresses and then increases C-mineralization, causing a loss of 0.14-7.17 mg-CO2-C g(-1)-C compared to the control (0.24-1.86 mg-CO2-C g(-1)-C) over 1-120 days. Negative priming was observed for BC compared to various BW amendments (-10.22 to -23.56 mg-CO2-C g(-1)-soil-C); however, it was trivially positive relative to that of the control (8.64 mg-CO2-C g(-1)-soil-C). Furthermore, according to the residual carbon and delta C-13 signature of postexperimental soil carbon, BC-C significantly increased (P < 0.05) the soil carbon stock by carbon sequestration in soil compared with various biowaste amendments. The results of cumulative CO2-C emissions, relative priming effects, and carbon storage indicate that BC reduces C-mineralization, resulting in greater C-sequestration compared with other BW amendments, and the magnitude of this effect initially increases and then decreases and stabilizes over time, possibly due to the presence of recalcitrant-C (4.92 mg-C g(-1)-soil) in BC, the reduced microbial activity, and the sorption of labile organic carbon (OC) onto BC particles
In-situ oxidative degradation of sulfamethoxazole by calcium peroxide/persulfate dual oxidant system in water and soil
No full textCalcium peroxide (CaO₂) and persulfate (PS) dual oxidant system is an innovative in-situ chemical oxidation (ISCO) technique for the restoration of contaminated groundwater. Several field applications also confirm its efficacy in remediating the groundwater, however, published articles are rarely present. In this work, the performance of the CaO₂/PS system was examined for the degradation of sulfamethoxazole (SMX) in the SMX polluted soil and water. Results indicated that SMX could be efficiently degraded with CaO₂ and PS (2 g/L dosages for each oxidant) around neutral pH (7), and 95.8% pollutant removed after 36 h of reaction time. The removal efficiency of SMX improved as the concentrations of CaO₂ and PS were increased. Moreover, SMX removal was significantly decreased with the increase of initial solution pH. This dual oxidant system at 30 °C was also used for the remediation of SMX (10 mg/kg) spiked soil. Soil degradation experiment was performed at 150 rpm of shaking speed using soil slurry (soil/water; 1/1 ratio) at pH 7. Dual oxidant dosage was kept at 2 g/L CaO₂ and 2 g/L PS. The results showed that this dual oxidant system is also very efficient for the antibiotics SMX degradation in the soil system. Overall, an insight knowledge and practical information gained from this work will help in the treatment of SMX contaminated soil and water as well as wastewater with CaO₂/PS dual oxidant system
Effects of biochar on uptake, acquisition and translocation of silver nanoparticles in rice (Oryza sativa L.) in relation to growth, photosynthetic traits and nutrients displacement
No full textRapid development in nanotechnology and incorporation of silver nanoparticles (AgNPs) in wide range of consumer products causing the considerable release of these NPs in the environment, leading concerns for ecosystem safety and plant health. In this study, rice (Oryza sativa) was exposed to AgNPs (0, 100, 200, 500 and 1000 mg L-1) in biochar amended (2 %w/v) and un-amended systems. Exposure of plants to AgNPs alone reduced the root and shoot length, biomass production, chlorophyll contents, photosynthesis related physiological parameters as well as macro-and micronutrients in a dose dependent manner. However, in case of biochar amendment, physiological parameters i.e., net photosynthesis rate, maximum photosynthesis rate, CO2 assimilation, dark respiration and stomatal conductance reduced only 16, 6, 7, 3 and 8%, respectively under AgNPs exposure at 1000 mg L-1 dose. Meanwhile, biochar at all exposure level of AgNPs decreased the bioaccumulation of Ag in rice root and shoot tissues, thus alleviated the phyto-toxic effects of NPs on plant growth. Moreover, results showed that biochar reduced the bioavailability of AgNPs by surface complexation, suppressing dissolution and release of toxic Ag+ ions in the growth medium. The presence of biochar at least decreased 2-fold tissue contents of Ag even at highest AgNPs (1000 mg L-1) concentration. These finding suggested that biochar derived from waste biomass resources can be used effectively to prevent the bioaccumulation and subsequent trophic level transfer of emerging Ag nano-pollutant in the environment. (C) 2019 Elsevier Ltd. All rights reserved
