Waste water treatment is an important issue globally and the introduction of activated carbons as a tool for the same has significantly enhanced the efficiency of many waste water treatment methods. This text reviews the principal lignocellulosic indicators applied in the elaboration of activated carbons in various nations in continents like Asia, America, Europe and Africa. Various processes and trial conditions used to synthesize activated carbons, including analysis of the major stages of preparation such as carbonization and activation have been elaborated in this book. Additionally, latest specialized methods used in the process have also been discussed here. These include the procedures used to establish textural parameters, various spectroscopies to ascertain the chemical functionality (Raman, FT-IR, etc.) and other X-Ray procedures. Also, the uses of activated carbons synthesized from lignocellulosic precursors for wastewater treatment have been discussed. Particularly, the text is meant to shed light on the benefits and potential of activated carbons for the elimination of related toxic materials and impurities from water. Lastly, usage of pyrolysis process for the valorization of two typical Mexican farm wastes (orange peel and pecan nut shell) for energy creation and carbon generation has been reviewed in this text.