The pyrolysis of medlar seeds was performed at 350, 450, 550, and 650 °C with and without K2CO3, MgO, and expanded perlite (10 wt%). The maximum dichloromethane extract yield (6.70 wt%) was obtained at 450 °C in the pyrolysis experiments without catalyst, while the maximum bio-oil yield (50.3 wt%) was obtained at 650 °C in the presence of perlite. The dichloromethane extract and bio-oil yields decreased noticeably with the use of MgO and K2CO3. The bio-oils obtained from the non-catalytic runs mainly consisted of phenolic compounds. The use of catalysts had a noticeable effect on the composition and higher heating values of the bio-oils. The use of K2CO3 increased the relative content of 2-methoxyphenol at all tested temperatures and the relative content of 2,6-dimethoxyphenol and 2,6-dimethoxy-4-methylphenol increased with the use of expanded perlite at above 550 °C, while the use of MgO led to an increase in the relative content of 2,6-dimethoxy-4-methylphenol at above 550 °C. The bio-oil with the maximum higher heating value (30.4 MJ/kg) was obtained at 450 °C with the use of perlite. This study showed that medlar seeds are a good alternative source of waste biomass in the production of bio-oil that can be used as a biofuel.

Black cumin seed pulp (C), as well as biochar (CC) produced via pyrolysis of black cumin seed pulp were used to remove methylene violet 2B (MV) and basic yellow 28 (BY28) from aqueous solution. Adsorption isotherms and kinetics were applied at 10, 25, and 35 °C. The adsorption of methylene violet 2B and basic yellow 28 on the black cumin seed pulp and biochar surface was exothermic; the heat of adsorption values were lower than 0. The adsorption capacities of BY28-C, BY28-CC, MV-C, and MV-CC were 212.8, 625, 164, and 909 mg g-1 at 25 °C, respectively. The adsorption of black cumin seed pulp and biochar data were examined with the Freundlich, Langmuir, Temkin, Dubinin-Radushkevich (D-R), and Flory-Huggins (F-H) isotherm models. The kinetics of the adsorption were fitted to the pseudo first-order and pseudo second order equations. The pseudo second order equation gave a better fit than the pseudo first-order equation.