“…To date have been posted notes, manuals and articles for the establishment of programs for pre-treatment which includes control of pH value, for example: neutralization processes of liquid industrial waste (Herrera, 2000); control of pH for sewage treatment plant (Wilson et al, 2004); Ministry of Environment, Housing and Territorial Development (MEHTD or MAVDT for its acronym in Spanish ); environmental guide for the formulation of plans for pre-treatment of industrial effluents (MAVDT, 2002), US Environmental Protection Agency (EPA, 1987;EPA, 1991;EPA 1994;EPA 1998;EPA, 1999); in Mexico: industrial water treatment and reuse (UNAM, 2000); some other manuals and guides can be found at: Cortés et al, 2010;Wills et al, 2010.…”