Chapters authored
Biological Treatment of Petrochemical Wastewater
Petrochemical wastewater is inherent to oil industries. The wastewater contains various organic and inorganic components that need to be well managed before they can be discharged to any receiving waters. The complexity of the wastewater and stringent discharge limit push the development of wastewater treatment by combinations of different methods. Biological wastewater treatments that have been well developed for organic and inorganic wastewater treatment are thus a potential method for petrochemical wastewater management. This chapter summarizes the commonly applied petrochemical wastewater pretreatment methods prior biological treatments and compares different biological treatment systems? performance such as biological anaerobic, aerobic and integrated systems. Two case studies are presented for a high chemical oxygen demand (COD) contents petrochemical wastewater treatment in full-scale by applying Biowater Technology’s biofilm system continuous flow intermittent cleaning (CFIC) and a pilot-scale study by an integrated anaerobic and aerobic biofilm system hybrid vertical anaerobic biofilm (HyVAB). Both processes showed substantial (over 90%) COD removal, while the HyVAB system produced high methane content biogas that can be potentially used as an energy source. Studies of degradation of certain toxic chemicals, such as aromatic compounds in petrochemical wastewater, by the advanced treatment systems incorporating specific organisms can be of good research interest.
Part of the book: Petroleum Chemicals
Biofilm in Moving Bed Biofilm Process for Wastewater Treatment
A brief introduction of the long history of biofilm-based wastewater treatment is given together with basics of biofilm behavior and mechanisms in removal and transformation of pollutants. Moving bed biofilm reactor (MBBR) principles and applications of such are presented. Advantages and limitations of such solutions are given together with evaluations of emerging MBBR applications. The basis of biofilm processes and biofilm layer classification based on dissolved oxygen gradient is discussed. Organisms grow at the protected surface of the biocarrier where oxygen gradients create aerobic, anoxic, and anaerobic layers allowing simultaneous nitrification and denitrification in one MBBR (nitrification, nitritation, autotrophic, and heterotrophic denitrification). Combination of MBBR with activated sludge, continuous flow intermittent cleaning (CFIC®), and integration with anaerobic digestion increases the potential usage of MBBR for enhanced efficiency and energy recovery and is partly discussed as case studies (COD, ammonium, and solid removal). Biofilm thickness and scaling control can be crucial for MBBR performance. The type of carriers, filling degree, and operational conditions play a major role for process performance; hence, the effect of those parameters is presented.
Part of the book: Bacterial Biofilms