Environmental Engineering
M. Hazbehiean; N. Mokhtarian; A. Hallajisani
Abstract
More than 5.5 trillion cigarettes are manufactured, and approximately 4.5 trillion cigarette butts are being scattered across the globe per year. These cigarette butts are considered as one of the most hazardous wastes and environmental threats in the world. Thermochemical techniques can be used to turn ...
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More than 5.5 trillion cigarettes are manufactured, and approximately 4.5 trillion cigarette butts are being scattered across the globe per year. These cigarette butts are considered as one of the most hazardous wastes and environmental threats in the world. Thermochemical techniques can be used to turn biomass and solid wastes into valuable final products. Pyrolysis is a comfortable thermochemical technique for turning biomass into biochars, biofuels, briquette solid fuels, and further valuable products such as activated carbons, carbon black, and printing ink. In this study, it was attempted to review the available researches about pyrolysis of cigarette butts with an emphasis on transforming them into carbonated solid and liquid products. It was found that, in addition to the process variables, the type of cigarette butts treatment has a significant effect on the yield and quality of the finished goods. Further studies on the pyrolysis of cigarette butts, especially microwave-assisted pyrolysis and hybrid waste pyrolysis, seemed to be necessary. Solving the technical issues associated with the pyrolysis of cigarette butts to produce the value-added goods would contribute to their application in waste disposal and recycling of other resources. Future studies should focus on the separation methods with the help of gas products to provide the heat required in the reactor. Moreover, mixing the sewage sludge material, as a feed, with cigarette butts and application of appropriate models and experiments to attain the products with specific properties are recommended. The results of this study can be used to eliminate the hazards of the cigarette butts scattered in the environment and create the added value for the pyrolysis process.
U. Younis; M. Athar; S.A. Malik; M.H. Raza Shah; S. Mahmood
Abstract
Disastrous effect of nickel on spinach was discussed by number of authors but the effect of amendments like biochar with nickel on Spinacea oleraceaL. is not still discussed by any author of the world because biochar was used as soil amendments which play a vital role in reducing mobilization and uptake ...
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Disastrous effect of nickel on spinach was discussed by number of authors but the effect of amendments like biochar with nickel on Spinacea oleraceaL. is not still discussed by any author of the world because biochar was used as soil amendments which play a vital role in reducing mobilization and uptake of nickel by spinach plants. As nickel contaminated plants are very harmful for the consumption by living organisms. Nickel can be gathered in agronomic soils by anthropogenic actions such as Ni-Cd batteries. In this study, the growth, physiological, photosynthetic and biochemical responses of Spinacia oleracea grown in Ni-spiked soil (0, 25, 50 and 100 mg Ni/Kg soil) at three levels of cotton-sticks-derived biochar “CSB” (0, 3 and 5 %) were evaluated. The results exposed significant decrease in growth, photosynthetic, physiological, and biochemical traits of S. oleracea when grown in Ni-polluted soil. However, this decrease was less pronounced in CSB amended soil. A steady rise in the MDA (0.66 µg/g to 2.08 µg/g), ascorbic acid (1.24 mg/g to 1.57 mg/g)and sugar concentrations (1.73 mg/g to 2.16 mg/g)was observed with increased concentration of Ni. The increasing percentages of CSB from 3 % to 5 % decreased Ni concentrations in root and shoot of experimental plant. Higher production of chlorophyll, amino acids and protein with CSB amendment looked like alleviation in Ni toxicity. Therefore, it is concluded that, Ni toxicity and availability to the plants can be reduced by CSB amendments.