Removal of COD from petroleum refinery wastewater using electrocoagulation method

This research assessed the removability of chemical oxygen demand (COD) from petroleum effluent using aluminum-based electrocoagulation reactor. A series of batch flow studies have been conducted to evaluate the impact of current density, electrodes separation, and duration of treatment on the removal of COD from the refinery effluent. The COD levels were determined employing the remaining concentrations using spectrophotometer namely Hach-Lang and standard cuvette test (LCC 514, LCK 314, or APC 400). The findings of the current investigation indicate the capacity of the electrocoagulation technique in a relatively short processing time to reduce the COD levels. The greatest efficiency in removing COD has been determined to be 80.0%. After 100 minutes of electrolysis, a current density of 8 mA/cm2 and electrodes separation of 20 mm achieved the highest percentage removal.

Wastewater Treatment Using Constructed Wetland: Current Trends and Future Potential

Constructed wetlands (CW) is an environmentally friendly technique for removing pollutants from wastewater and has been applied to municipal wastewater, petroleum refinery wastewater, agriculture drainage, acid mine drainage, etc. The past decade has seen a remarkable number of innovations in the exponentially growing field of microbiology. This manuscript covers a critical review of key aspects of CW, such as various types of CW, the contaminants and their removal mechanisms, degradation pathways, challenges and opportunities, materials, applications, and theory with a focus on recent advances in the last three decades. In addition, an attempt has been taken to project future advances in the field of CW and facilitate these advances by framing key unsolved problems in CW. Guidelines are prepared for the fast-growing CW field through the standardization of key design aspects. This review covers the evaluation of the current state-of-the-art of CW technology and provides definitions and performance metric nomenclature in an effort to unify the fast-growing CW community. It also contains an outlook on the emerging trends in CW and proposes future research and development directions.

Bimetallic M–Cu (M = Ag, Au, Ni) Nanoparticles Supported on γAl2O3-CeO2 Synthesized by a Redox Method Applied in Wet Oxidation of Phenol in Aqueous Solution and Petroleum Refinery Wastewater

Three bimetallic catalysts of the type M–Cu with M = Ag, Au and Ni supports were successfully prepared by a two-step synthesized method using Cu/Al2O3-CeO2 as the base monometallic catalyst. The nanocatalysts were characterized using X-ray diffraction (XRD), temperature-programmed reduction of H2 (H2-TPR), N2 adsorption-desorption, scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and ultraviolet–visible spectroscopy with diffuse reflectance (DR-UV-Vis) techniques. This synthesized methodology allowed a close interaction between two metals on the support surface; therefore, it could have synthesized an efficient transition–noble mixture bimetallic nanostructure. Alloy formation through bimetallic nanoparticles (BNPs) of AgCuAlCe and AuCuAlCe was demonstrated by DR–UV–Vis, EDS, TEM and H2-TPR. Furthermore, in the case of AgCuAlCe and AuCuAlCe, improvements were observed in their reducibility, in contrast to NiCuAlCe. The addition of a noble metal over the monometallic copper-based catalyst drastically improved the phenol mineralization. The higher activity and selectivity to CO2 of the bimetallic gold–copper- and silver–copper-supported catalysts can be attributed to the alloy compound formation and the synergetic effect of the M–Cu interaction. Petroleum Refinery Wastewater (PRW) had a complex composition that affected the applied single CWAO treatment, rendering it inefficient.

REVIEW: MATHEMATICAL MODELLING OF HEAVY METALS REMOVAL FROM PETROLEUM REFINERY WASTEWATER

Adsorption is a commonly used procedure in environmental applications in the chemical industry. In comparison proposed mathematical models to explain batch adsorption as it relates to isotherms and kinetics, fixed-bed or column adsorption has a dearth of models to describe and forecast. While the latter is the most common alternative in practice. The current analysis begins with a brief overview of basic concepts and mathematical models used to characterize batch adsorption's mass transfer and isotherm behavior, which dominates Natural adsorption behavior in columns. Following that, the commonly used models for predicting the breakthrough curve, such as the Clark, Thomas, Adams-Bohart, and Yoon-Nelson models, are fleetingly discussed from a mathematical and process perspective. Their fundamental characteristics are also discussed, including their benefits and intrinsic flaws. This analysis can aid those who are involved in adsorption in columns in selecting or developing a correct and realistic model for their research and applications.