This work reports the batch and dynamic flow biosorption conditions for Reactive Red 45 clue using Agaricus bisporus/Thuja orientalis biomass mixture (ABTOC). Experiments were performed to determine optimum pH, biomass amount, contact time, temperature, dye concentration, and flow rate. The applicability of different kinetic and isotherm models for the biosorption process was evaluated. Biosorption showed a highly pH dependent profile. Under optimized batch conditions up to 93.04% dye could be removed from solution in a relatively short time. Kinetic experiments suggest that the biosorption process followed the pseudo-second-order model in comparison to intraparticle diffusion and the pseudo-first-order models. Thermodynamic data confirm that the biosorption process is spontaneous and endothermic in nature. Besides, the highest regression coefficient (r(2) approximate to 1) for the Langmuir model indicates the monolayer coverage of biomass by RR45 dye molecules (q(max) = 108.90 mg g(-1)). Column studies showed. that ABTOC effectively removes RR45 dye with a maximum biosorption yield of similar to 100%. ABTOC was able to give nearly 96% dye removal in the presence of Na+, K+, Mg2+, Ca2+, Pb2+, Ni2+, CU2+, and Cd2+ ions. Our results revealed that ABTOC could be employed as an effective and low-cost alternative biosorbent material for removal of reactive textile dyes from contaminated effluents.