Industrial reuse of petrochemical effluents: A case study of ultrafiltration and reverse osmosis

Abstract

The petrochemical industry uses high volumes of water in its production processes and generates effluents that have a great potential for reuse in production processes. The reuse of these effluents is, therefore, an alternative for the sustainable development of the sector. This study aimed at evaluating the application of ultrafiltration (UF) and reverse osmosis (RO) in the treatment of petrochemical effluents for the production of industrial reuse water, reducing environmental impacts caused by the disposal of effluents in the soil. The experiments were carried out with effluents named waste stabilization pond 1 (WSP-1), waste stabilization pond 8 (WSP-8) and an inorganic effluent (INO), which was used as feedwater in the pilot unit with a treatment capacity of 1 m³.h–1. The parameters chosen for evaluation in the treated effluents were calcium, magnesium, chloride, sulfate, electrical conductivity (EC), total organic carbon, color, chemical oxygen demand (COD), pH, total suspended solids and turbidity. Membrane permeate fluxes were determined to evaluate the performance of the pilot system. After treatment and characterization of each effluent, the results were compared to define the most suitable effluent to achieve the quality required for industrial reuse. The results showed that the proposed UF/RO treatment provided a stable flux for the WSP-8 effluent. Conversely, the other streams showed an accentuated decrease in flux, which indicates fouling processes of the UF and RO membranes. As for the efficiency of the treatment, the process removed compounds of interest such as COD above 90%, salts and EC above 92% for the three assessed effluents. Thus, considering all aspects evaluated in this study, WSP-8 was the most suitable to be used as feed in the pilot system with UF and RO. The permeate produced presented the necessary quality for reuse in the industries of the Southern Petrochemical Complex, presenting equivalent characteristics to those of clarified water. Thus, the reuse of treated petrochemical effluents may be an important alternative source of water resources in face of availability and scarcity restrictions in industries in southern Brazil.

Electrodeionization for Wastewater Reuse in Petrochemical Plants

“…Silica, magnesium, nitrate, iron, and other contaminants are present in lower concentrations, but well above the values required for high-purity water as those used in high-pressure boilers. Both contaminants and concentrations detected are in line with studies previously carried out with the aforementioned tertiary petrochemical effluent [15,16,22,23,30].…”

“…Nevertheless, the RO permeate flux was restored to its average after a simple cleaning procedure consisting of rinsing for 5 min with the RO perm This behavior with a low variation indicates that the pre-treatment with UF allows w production with sufficient quality to feed the RO, minimizing fouling on the membrane, as recommended by Jafarinejad [31]. Furthermore, adding biocides contributed to the maintenance of the stability of the RO permeate flux [16]. More the EC of the RO permeate remained below 30 µS cm −1 throughout the evaluated pe classifying this stream as suitable for feeding EDI, which requires feed water with a lower than 40 µS cm −1 .…”

“…Subsequently, these wastewaters are combined, treated in eight stabilization ponds in series, and sprayed on soil. A more detailed description of the wastewater treatment systems used in the SBPC can be found in previous studies [16,22,23].…”

“…This hybrid system takes advantage of tertiary petrochemical wastewater, and operates at low pressures, reducing energy consumption. The benefits of this approach include not only the energy savings associated with wastewater disposal, but also reduced maintenance costs of current sprinkler and wastewater drip networks, as well as savings in monitoring efforts in these sprinkler areas [2,16]. Furthermore, the implementation of the reuse system offers additional advantages, such as interrupting the degradation process of the soil currently used for wastewater disposal.…”