Monitoring and control of anaerobic digesters treating industrial effluents

Increasing charges by the private utilities for the treatment of industrial waste water are making on-site effluent treatment more attractive. On-site anaerobic digestion is increasingly being used by food processing factories as a cost effective solution to waste liquid waste disposal. Discharge of treated effluent to sewer or water course requires compliance to a maximum admissible concentration (MAC) value, therefore, there is a need for careful control of on-site waste water treatment. This research investigates the treatment of effluent from instant coffee production. This results in a liquid waste that contains recalcitrant and toxic compounds formed during the roasting process. This waste varies in strength and composition according to the different processes that are performed in the manufacture of instant coffee. Anaerobic filters are particularly attractive for wastes containing recalcitrant or inhibitory compounds requiring a long sludge age. Therefore, this study was aimed at firstly investigating the treatability of coffee waste, using anaerobic filters; and secondly monitoring and control of the digestion process in order to maintain a constant effluent quality. [Continues.

Pathways to Water Sector Decarbonization, Carbon Capture and Utilization

The water sector is in the middle of a paradigm shift from focusing on treatment and meeting discharge permit limits to integrated operation that also enables a circular water economy via water reuse, resource recovery, and system level planning and operation. While the sector has gone through different stages of such revolution, from improving energy efficiency to recovering renewable energy and resources, when it comes to the next step of achieving carbon neutrality or negative emission, it falls behind other infrastructure sectors such as energy and transportation. The water sector carries tremendous potential to decarbonize, from technological advancements, to operational optimization, to policy and behavioural changes. This book aims to fill an important gap for different stakeholders to gain knowledge and skills in this area and equip the water community to further decarbonize the industry and build a carbon-free society and economy. The book goes beyond technology overviews, rather it aims to provide a system level blueprint for decarbonization. It can be a reference book and textbook for graduate students, researchers, practitioners, consultants and policy makers, and it will provide practical guidance for stakeholders to analyse and implement decarbonization measures in their professions

Complete mechanical model of a very large submerged membrane bioreactor

Membrane bioreactors (MBRs) are successfully being adopted in super-large-scale (>100,000 m3 .d-1 ) applications due to several advantages, mainly superior and consistent effluent quality. Moreover, the significant reduction in the membrane and operating costs has contributed to its wider acceptance. Despite their considerable evolution in the recent past and large-scale applications in municipal wastewater treatment, fouling and the cost associated with its mitigation are still hot topics and need the attention of researchers and academia to optimize and reduce the expense of MBR in the range of the conventional activated sludge process (CASP). Mathematical modeling is a great tool to explore the model-based optimization of operating costs associated with fouling mitigation strategies. For this, a comprehensive and integrated process model must be adapted, calibrated, and validated at a super-large-scale facility. MBR involves complex interactions between biology and filtration, and its modeling is challenging without considering these interactions. In the recent past, integrated models have been developed and applied to MBRs, ranging from bench to pilot scales and rarely for full-scale facilities of capacity up to 15,000 m3 .d-1 . In this work, a superlarge-scale MBR plant with a design capacity of 348,000 m3 .d-1 is dynamically modeled to simulate the depollution and filtration-fouling processes. The integrated model combines biochemical (ASM3-SMP-EPS-Bio-P, aeration, chemical precipitation), resistance in series (RIS) fouling, and energy sub-models. The comprehensive, integrated model is capable of simulating a) biological processes to describe the stoichio-kinetic activity of the biomass for carbon oxidation and nutrient removal (i.e., Nitrogen and Phosphorus) coupled with EPS-SMP production and degradation processes; b) the role of biological process aeration in carbon oxidation and nitrification under the influence of MLSS; c) the numerical balance of the volumes of the influent, effluent, sludge and all internal and external recirculation; d) coagulant addition inducing chemically enhanced phosphorus removal (CEPR) in addition to enhanced biological phosphorus removal (EBPR); e) fouling dynamics associated with synchronized filtration-relaxation, intermittent air-scouring and backwashing under the influence of transmembrane pressure (TMP), temperature, MLSS, and bound EPSs concentration, and f) specific energy consumption. The model was calibrated using one-week data collected during the first experimental campaign and was validated against 92 days of data from the plant with and without the addition of FeCl3. The calibrated integrated model provided an acceptable correspondence for pollutants (COD, NOx, NH4, PO4 3- , MLSS, EPSs, and SMPs) removal and prediction of the TMP, a direct indicator for fouling development. The model also successfully produced acceptable datasets not available from routine measurements, e.g., the evolution of the biomass and transformation of the pollutants in each reactor in series. Moreover, the model can provide detailed insights into reversible and irreversible fouling dynamics under the synchronized influence of multiple fouling abatement controls, including filtration-relaxation, intermittent air-scouring, and backwashing. In order to be used to develop model-based controls and intelligent decision-making tools to optimize the functioning of the full-scale MBRs, particularly the air-scouring and activation and de-activation of the chemical washes to save energy and chemicals, this model would have to be validated in fouling conditions. Since it was not possible to test the limits of the model, the sensitivity analysis approach was investigated