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Alternative, renewable and carbon-neutral fuels are an urgent requirement. Pyrolysis has received the most attention in the conversion of biomass into fuel. The main disadvantages of chemical and physical properties of pyrolysis crude bio-oil include its high oxygen content and acidity. Catalytic fast pyrolysis can overcome this problem. Rice straw is an abundant biomass residual that can be of environmental negative impact and is not of proper use. Therefore, this research work introduces the use of this residual in the production of fuel sources by one-step catalytic pyrolysis with the reusability of the employed catalyst. A waste extraction catalyst modified with acidic and nickel sites has been prepared and was utilised for the proposed target in this study. The removal of silica, lignin and minerals by treatment of the rice straw with KOH and then HNO3 in a green terminated process improved the catalytic biomass conversion from 83% to 96% at a catalyst dose of 5%, at 250°C. The pre-treatment of the rice straw enables the reusability of the catalyst in direct catalytic pyrolysis where the employed catalyst exhibits good stability in four consecutive runs. The used KOH and HNO3 were neutralised by mixing to produce KNO3 as a valuable fertiliser. [ABSTRACT FROM AUTHOR]

Today, one of the most important problems for humans is disease and mortality due to air pollutants, especially in large and industrial cities. This research is to evaluate the health risk of children and adults' exposure to heavy metals and PAHs in the air of cities of Arak, Isfahan, Ahvaz, Tabriz, Shiraz, Karaj and Mashhad and identifying the factors affecting pollution, based on sampling data from 120 stations, was done during 2019–2020. ICP OES and GC/MS were used to determine the amount of heavy metals and PAHs, respectively. US-EPA models were used for carcinogenic and non-carcinogenic risk assessment and Factor analysis models, PCA, CFA with SPSS and LISREL software were used to identify factors affecting contamination. The risk index for children and adults, except in the cities of Arak and Isfahan, was obtained within the allowable range and the carcinogenicity and non-carcinogenicity risk of all metals, except Mn in Arak and Isfahan for children and adults was seen below the threshold. The carcinogenic risk of all PAHs was also obtained to an acceptable extent. During the statistical analysis, combustion of fuels, vehicle exhaust, tyre wear and industrial activities were identified as the most important factors in causing pollution. [ABSTRACT FROM AUTHOR]

Huge quantities of different dyes are generated by various industries such as cosmetic, leather, printing and textile and food. This study aimed to generate and apply tire-derived activated carbon magnetised with the Fe3O4 nanoparticles (MAC) for the removal of reactive blue 19 (RB19) dye from aquatic solutions. FE-SEM, VSM, XRD, FTIR and BET analyses were used to determine MAC properties. Under optimal conditions of pH 3, the initial concentration of dye 100 mg/L, the composite dose 1 g/L and the reaction time of 45 min, the removal efficiency for RB19 was 93.22%. Isotherm findings illustrated that RB19 adsorption onto the MAC followed the Langmuir model. Moreover, the absorption kinetics is well interpreted by the pseudo-second-order model in low scrutinised concentrations. The SBET and total pure volume for the MAC were 421.11 m2 g−1 and 0.467 cm3 g−1. Under the optimum conditions, maximum adsorption capacity of the MAC in Langmuir model enhanced to the amount of 119.05 mg/g. Also, the reusability (with NaOH) of the MAC revealed about 21% decreases in the removal efficiency within five consecutive runs. It is concluded that the application of the magnetised activated carbon due to its high efficiency in removing RB19 from laboratory and actual samples can be evaluated in future studies to be utilised in real scales. [ABSTRACT FROM AUTHOR]