Low-cost and renewable adsorbent activated carbon from lignocellulosic biomass is a focus of worldwide concern due to its readily available waste disposal problems in the environment. Physical and chemical processes are the main procedures forproduction of biomass-activated carbon (AC). Activating lignocellulosic biomass by chemical methods in terms of energy performance, lower timecarbonization, and temperature is mutual forthe production of activated carbon. Out of chemical activating agents (H₃PO₄, H₂SO₄, ZnCl₂, FeCl₃, NaOH, KOH, and K₂CO₃), H₃PO₄ is the most commonly used chemical activating agent during the synthesis of activated carbon from lignocellulosic biomass because of its ease of recovery, low environmental impact, and higher carbon yield. The surface area of most activated carbon from lignocellulosic biomass by H₃PO₄was in the variability of 456.1–2806 m²/g, yielding 26.1–85 % and an extreme adsorption capacity of 2.5–89.29 mg/g. And also, high acids to precursor ratio and activation temperature of AC were synthesized from lignocellulosic biomass. Generally, the advantage of this review paper, gathers evidence from currently published articles deliberating chemical composition, proximate values, biomass activation methods, the elemental composition of lignocellulosic biomass, physio-chemical properties of different lignocellulosic materials AC synthesized using a phosphoric acid activation agent, and the usage of derived activated carbon through phosphoric acid activation for water disinfection, solute organic matter, energy storage, and heavy metal removal.