Javier Miguel Ochando Pulido

A review on the use of membrane technology and fouling control for olive mill wastewater treatment.

Olive mill effluents (OME) by-produced have significantly increased in the last decades as a result of the boost of the olive oil agro-industrial sector and due to the conversion into continuous operation centrifugation technologies. In these effluents, the presence of phytotoxic recalcitrant pollutants makes them resistant to biological degradation and thus inhibits the efficiency of biological and conventional processes. Many reclamation treatments as well as integrated processes for OME have already been proposed and developed but not led to completely satisfactory and cost-effective results. Olive oil industries in its current status, typically small mills dispersed, cannot afford such high treatment costs. Furthermore, conventional treatments are not able to abate the significant dissolved monovalent and divalent ions concentration present in OME. Within this framework, membrane technology offers high efficiency and moderate investment and maintenance expenses. Wastewater treatment by membrane technologies is growing in the recent years. This trend is owed to the fact of the availability of new membrane materials, membrane designs, membrane module concepts and general know-how, which have promoted credibility among investors. However, fouling reduces the membrane performances in time and leads to premature substitution of the membrane modules, and this is a problem of cost efficiency since wastewater treatment must imply low operating costs. Appropriate fouling inhibition methods should assure this result, thus making membrane processes for wastewater stream treatment both technically and economically feasible. In this paper, the treatment of the effluents by-produced in olive mills, generally called olive mill wastewaters, will be addressed. Within this context, the state of the art of the different pretreatments and integral membrane processes proposed up to today will be gathered and discussed, with an insight in the problem of fouling.

Comparison of critical and threshold fluxes on ultrafiltration and nanofiltration by treating 2-phase or 3-phase olive mill wastewater

Comparison of Critical and Threshold Fluxes on Ultrafiltration and Nanofiltration by Treating 2-Phase or 3Phase Olive Mill Wastewater Marco Stoller*, Javier Miguel Ochando Pulido , Angelo Chianese a a University of Rome “La Sapienza”, Department of Chemical Engineering, Via Eudossiana 18, 00184 Rome, Italy b University of Granada, Department of Chemical Engineering, Granada, Spain * marco.stoller@unitoma1.it

Optimized design of Wastewater stream treatment processes by membrane technologies

Optimized Design of Wastewater Stream Treatment Processes by Membrane Technologies Marco Stoller*, Javier Miguel Ochando Pulido, Olga Sacco a Department of Chemical Materials Environmental Engineering, ‘La Sapienza’ University of Rome, Rome, Italy b Department of Chemical Engineering, University of Granada, Granada, Spain c Department of Chemical Engineering, University of Salerno, Salerno, Italy marco.stoller@uniroma1.it

On the relationship between suspended solids of different size, the observed boundary flux and rejection values for membranes treating a civil wastewater stream

Membrane fouling is one of the main issues in membrane processes, leading to a progressive decrease of permeability. High fouling rates strongly reduce the productivity of the membrane plant, and negatively affect the surviving rate of the membrane modules, especially when real wastewater is treated. On the other hand, since selectivity must meet certain target requirements, fouling may lead to unexpected selectivity improvements due to the formation of an additional superficial layer formed of foulants and that act like a selective secondary membrane layer. In this case, a certain amount of fouling may be profitable to the point where selectivity targets were reached and productivity is not significantly affected. In this work, the secondary clarifier of a step sludge recirculation bioreactor treating municipal wastewater was replaced by a membrane unit, aiming at recovering return sludge and producing purified water. Fouling issues of such a system were checked by boundary flux measurements. A simple model for the description of the observed productivity and selectivity values as a function of membrane fouling is proposed.

The boundary flux: New perspectives for membrane process design

The Boundary Flux: New Perspectives for Membrane Process Design Marco Stoller*, Javier Miguel Ochando Pulido, Benedetta de Caprariis, Nicola Verdone, Luca Di Palma, Angelo Chianese University of Rome “La Sapienza”, Dept. Of Chemical Materials Environmental Engineering, Via Eudossiana 18, 00184 Rome, Italy University of Granada, Dept. Of Chemical Engineering, Granada, Spain marco.stoller@uniroma1.it