Behavior of organic fraction in water separated from extracted crude oil with anaerobic digestion

the removal of different organic fractions of two separated waters from extracted crude oil (app), applying the micro-sara method, was evaluated in this work using upflow anaerobic sludge blanket (uasb) reactors of 2.5 l of useful volume. the treatment conditions were: hydraulic retention times of 24 h, temperature 37°c and continuous flow, during an approximated period of three months. in order to evaluate the stability of uasb reactors, the chemical oxygen demand (cod), ph and total alkalinity were measured. the micro-sara method was applied in effluent and influent samples to reactors. a high removal of fractions in separated waters from extracted light crude oil (appl) was obtained, with an average value of 94% for aromatic hydrocarbons. for the separated waters from extracted medium crude oil (appm), the elimination was smaller (67%). the results indicate important improvements in water quality by the anaerobic microorganisms presents in the reactor. a study of this system on pilot scale is recommended.