modern water treatment by electrochemical oxidation

Interestingly Fentons Reagent has produced impressive contaminant reduction results in these applications, but the operational expense (OPEX) was much greater than biological treatment.ĪOPs that use eBeams and plasma arcs have not yet been tried in the refinery and petrochemical applications because more research and pilot tests need to be conducted.Īround seven years ago, eAOPs were tested on refinery and petrochemical wastewaters using two-dimensional electrodes. The AOPs that used hydrogen peroxide also experienced high failure rates in these same applications, mainly because of the wide range of competing reaction species present in these wastewater streams. Most of these attempts failed for the same reason: The temperature of these wastewater streams was too high, and as such the cost of ozone was too high.Ī few successes were observed when the wastewater was cooled. Over the last five years, several of the AOP technologies have been pilot tested for refinery and petrochemical wastewater applications both at the central wastewater treatment plant (WWTP) as well as for upstream pretreatment.

In short, when electrons leave the anode, a hole in the valence band of the semiconductor then reacts with water to create hydroxyl radicals. It is important to note that AOPs are markedly different from simple oxidizers such as chlorine, peroxide, permanganate, UV light by itself, etc., which are much weaker oxidizers than the hydroxyl radical.Įlectrochemical AOPs (eAOP) generate hydroxyl radicals from electrochemical reactions on the surface of the semiconductor anode in an electrochemical cell. The range of processes in this family deploy a variety of combinations and configurations using ultraviolet (UV) light and hydrogen peroxide, hydrogen peroxide and ozone, catalytic ozone, ultrasound, cavitation, eBeams, plasma arcs, and electricity, to name a few.

It is this degree of difficulty for bioreactor control in these two industries that has motivated many to investigate treatment alternatives for improved performance. Many engineers believe that these two industrial wastewaters are the most difficult to treat using biological treatment because there are many recalcitrant and inhibitory compounds in the wastewater influent.Īs such and especially in these two industries the overwhelming choice of biological treatment is activated sludge (AS) because of its flexibility for process control in the face of influent concentration variability. In the petrochemical industry, the range of complex hydrocarbons is even greater, although there are generally far lower levels of free oil. In the oil refining industry, a wide range of hydrocarbon species and lots of free oil add substantially to the organics loading.

Modern Water Treatment By Electrochemical Oxidation Trial Wastewater Treatment.

Modern water treatment by electrochemical oxidation