<p>Biomass utilization leads to decrease environmental pollution as well as decrease greenhouse gas emissions. Therefore, this renewable resource can be used to produce various value-added bio-chemicals such as bio-oil, bio-char, and bio-gas. In this work, catalytic pyrolysis of the biomass of pistachio shells (P.S.) was studied to investigate the influence of different catalysts on the yields of the main pyrolysis products and the ability of the produced bio-chars to adsorb various contaminants. The produced bio-oil and biosorbents were characterized by GC–MS, FTIR, XRD, SEM–EDS, and BET analysis. Based on the reported results, by using CaCO₃ and CaO catalysts in the catalytic pyrolysis of H₃PO₄ activated P.S., the maximum yields of bio-oil were obtained (greater than 38 w%). However, the maximum yield of bio-char and minimum yield of bio-gas were obtained by using ZnO catalyst. The produced bio-chars demonstrate good abilities to adsorb various pollutants from the contaminated water. The isotherm studies depicted that the Sips isotherm model with the R² values closed to one is the best-fitted model with the experimental adsorption data. According to the Langmuir isotherm model, the biosorbent produced by catalytic pyrolysis of P.S. using the ZnO catalyst was the best adsorbent of methylene blue and cadmium ions, with the maximum adsorption capacities of 868 and 118.3&#xa0;mg/g, respectively. Furthermore, the best adsorbent of methyl orange is the biosorbent produced by the pyrolysis of H₃PO₄ chemical activated P.S. with a maximum adsorption capacity of 49.03&#xa0;mg/g. The potential applicability of this process is demonstrated by using this available agricultural waste as a low-cost source of different biosorbents and bio-oil.</p> Graphical Abstract <p></p>