In this study, the effectiveness of the electrocoagulation (EC) process was evaluated based on the reduction of organic and nitrogenous contaminants in landfill leachate. A three-compartment electrochemical reactor as pre-treatment of stabilized landfill leachate was carried out ahead of biological treatment. The removal efficiencies of COD, BOD, ammonia, and nitrate were analyzed at pH 4, 6, and 8 with the current densities of 20.83 and 29.17 mA•cm -2 . At pH 4, the highest removal of COD and NH 4 + was obtained, i.e., in the range of 72-81% and 43-59%, respectively. The ratio of BOD 5 /COD was increased after EC, from initially 0.11 to 0.32 at pH 4. In addition, EC effectively removed humic substances in the leachate by targeting a large amount of high molecular weight humic substances, with around 10 3 kDa. However, the higher removal efficiency observed at higher current density leads to higher specific energy consumption. At a current density of 29.17 mA•cm -2 , the specific energy consumption obtained in EC was around 10-17 Wh•g -1 COD and 99-148 Wh•g -1 NH 4 + . This could be decreased up to 50% at an applied current density of 20.83 mA•cm -2 with slightly lower efficiencies.

The presence of toxic algae, such as Microcystis aeruginosa (MA), in drinking water treatment plants (DWTPs) would contribute to algal organic matter (AOM) as precursors toward disinfection by-products (DBPs). Electrocoagulation–flotation (ECF) has shown promising performance in minimizing algal cells from water and dissolved AOM. This study aimed to investigate the effect of current density (CD) and pH on alumina (Al)-based ECF for removing MA cell and DBPs precursors from cyanobacteria-laden water. The performance of Al-based ECF was evaluated at various CD and pH conditions within 20 min. In addition, the total halogenated DBPs formation of the treated suspension after ECF was quantified. At pH 8, the ECF process with 5 mA/cm2 exhibits the most significant reductions in MA cell and soluble AOM, accounting for 97 and 56%, respectively. Additionally, the precursors of trihalomethanes (THMs) and haloketones (HKs) can be effectively removed with flotation despite their significant release at EC. The tremendous reduction of humic acid-like (HAL) substances in extracellular organic matter (EOM) fraction by ECF leads to the minimized THMs formation potential. In summary, Al-based ECF at pH 8 is effective to remove cyanobacteria and minimize the precursors of regulated THMs along with an insignificant reduction in regulated haloacetic acids (HAAs) precursors.

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COVID-19 has disrupted all aspects of human life. To mitigate the impact of the pandemic, several efforts have been taken, including by Indonesian scholars abroad. This book entitled Indonesia Post-Pandemic Outlook: Environment and Technology Role for Indonesia Development explores environment and technology issues and topics related to the COVID-19 pandemic and discusses post-pandemic recovery efforts in Indonesia. Comprising of 19 chapters, this book is divided into four sections. The first section, disaster and greening management development, discusses insights for a better solution in disaster prevention and development of greening management. Second, waste and pollution management development, explores options in development of waste and pollution management such as potentials uses of membrane technology, remediation of textile dyes, biochar industry, and also discussion on persistent organic pollution and microplastics. Third, food defense and security development, explores the potentials of food security and management in utilizing the potential of coastal sand marginal land resources, IoT and smart packaging, and smart food supply chain. The last part, human resource and public service development, discuses developments on management of education system, public transportation, e-government, and health information system. We hope that this book can be a valuable reference for stakeholders, policymakers, as well as society to recover from the pandemic crisis and find better solutions to benefit future generations.