Activated Sludge Process Research Articles

Mathematical model of dissolved microbial products in sewage treatment system

Water is the source of life, but all kinds of water resources in the world are suffering from different degrees of pollution. Water pollution leads to a serious shortage of available fresh water resources, and sewage treatment is the main way to solve water pollution. For the sewage after biological treatment of activated sludge, the organic matter contained in the effluent is mainly the dissolved microbial products (SMPs) produced in the process of microbial metabolism. The composition of SMPs is complex, mainly including macromolecular substances such as protein, polysaccharide, humic acid and DNA and cell fragments. The mathematical model of activated sludge is a quantitative description of the mathematical relationship between substrate degradation parameters and microbial growth. Starting from the Monod equation representing the relationship between substrate consumption and microbial growth, it combines the reactor theory and microbiology theory in the chemical field. Based on the principle of conservation of materials and Monod equation, the mathematical expression of organic degradation model was determined according to the collected data and empirical values of parameters. The general idea of activated sludge model No.1 (ASM1) for activated sludge process simulation was introduced, and the influence of sludge concentration on SBR process water treatment was explored. It was found that the removal rate of COD, ammonia nitrogen, total nitrogen and total phosphorus increases with the increase of sludge concentration. When C/N=8, the removal rate of ammonia nitrogen increased from 62% to 81%, and the removal rate of total nitrogen increased from 64% to 82%, with the most obvious effect.

Characteristics of Nitrogen Removal from an Integrated Fixed-Film Activated Sludge (IFAS) System and the Relationship Between Activated Sludge and Biofilm Interactions

In order to investigate the enhancement mechanism of modified three-dimensional elastic filler (MTEF) on the nitrogen removal performance of the integrated fixed-film activated sludge (IFAS) process, and to clarify the interactions between competition and synergy between activated sludge and biofilm in the IFAS system, an IFAS reactor (T2) filled with MTEF was employed for the study, while a sequencing batch reactor activated sludge process (SBR) reactor (T1) was utilized for comparison. IFAS and SBR reactors were operated over an extended period at ambient temperature to assess the enhancement of pollutant removal performance with the addition of the filler to investigate the competitive dynamics between activated sludge and biofilm under varying influent water qualities (C/N, N/P, and organic loading), and to analyze the synergistic relationship between activated sludge and biofilm at the microbial level using high-throughput sequencing technology. The results demonstrate that throughout the entire operational phase, reactor T2 exhibited superior pollutant removal efficiency. Compared to reactor T1, reactor T2 achieved an average increase in the removal rates of COD, ammonia nitrogen, and total nitrogen by 13.07%, 12.26%, and 28.96%, respectively. The findings on the competitive dynamics between activated sludge and biofilm indicate that the nitrification volumetric load of the IFAS system is significantly higher than that of a pure activated sludge system, suggesting that the IFAS system possesses enhanced nitrification capabilities. Furthermore, when dealing with wastewater characterized by low C/N ratios and high phosphorus pollution, or under substantial organic loads, the biofilm holds a competitive edge and the IFAS system exhibits improved stability. High-throughput sequencing data reveal that the microbial community structures in activated sludge and biofilm can influence each other, thereby enabling the IFAS system to effectively enrich denitrification-related functional microbial populations. Additionally, the biofilm has a certain enhancing effect on the expression levels of nitrogen metabolism-related functional genes in the activated sludge phase microorganisms, indicating that, in addition to competitive interactions, there is also a synergistic effect between the biofilm and activated sludge.

Microplastics in wastewater plants: A review of sources, characteristics, distribution and removal technologies

Microplastics (MPs) are widespread in everyday life, and since wastewater treatment plants (WWTPs) serve as an important route for MPs to enter natural water bodies, a thorough understanding of the distribution and removal of MPs in wastewater treatment plants is of great importance. This article provides a comprehensive overview of the measured distribution of MPs and the current status of their removal in wastewater treatment plants. The main sources of MPs in wastewater treatment plants are personal care products in domestic wastewater, textile clothing and industrial wastewater made from plastics, textile factories and the friction of road tires. The MPs that entered the sewage treatment plant were predominantly in the form of fibers, fragments, granular MPs and other types of MPs. The size of MPs is divided into three categories: <0.5 mm, 0.5–1 mm and 1–5 mm. At all treatment stages in wastewater plants, 56.8–88.4 % of MPs are removed in primary treatment, but the primary sedimentation and degreasing stages remove most MPs. The efficiency of the activated sludge process for secondary treatment is inconsistent and is generally between 42.1 and 99.2 %. The coagulation, filtration and disinfection stages of tertiary treatment all have some MPs removal capacity. In addition, novel removal technologies are also described, such as modified filtration technology, membrane separation technology, electroflocculation, sol-gel and photocatalysis. These novel removal technologies can further limit the entry of microplastics into natural water bodies through sewage treatment plants and improved sewage treatment processes help reduce the risk of MPs entering the natural environment through sewage treatment plants. This article will provide reference for the distribution and removal of microplastics in various levels of WWTPs.

Metaheuristic assisted neural differential equation modeling in activated sludge process

Metaheuristic assisted neural differential equation modeling in activated sludge process

Electric-field nanobubbles: A step change in nanobubble engineering, and its “coming of age”

Electric-field nanobubbles: A step change in nanobubble engineering, and its “coming of age” Niall J. English, from Chemical Engineering at University College Dublin, discusses how electric-field nanobubbles have displaced their mechanically-generated counterparts in performance and sustainability. Limited solubility of gases in water, such as oxygen, is a fundamental challenge. In ecosystems and the environment, lack of dissolved oxygen (DO) is a major reason for fish kills and water bodies being blighted by algal blooms, in addition to lack of effectiveness of activated-sludge processes in water treatment or poorer-than-hoped results in irrigation. Nanobubbles (NBs) are tiny gas bubbles on the nanometre (nm) scale. They may be thermodynamically metastable for up to many months, or sometimes even longer, and have enhanced gas-transfer properties and substantial industrial potential. The concept of NBs versus traditional, coarser bubbles – with the latter subject to buoyancy phenomena, while NBs are relatively impervious to rising – in essence, “subverts” Stokes’ Law of bubble rising – and have an excellent area-to-volume ratio. If NBs are generated well – indeed, the art of “nanobubble engineering”, as it were – NBs lead to important and useful applications.

The impairment of joint tetracycline and copper oxide nanoparticle exposure on activated sludge

The increasing usage of two emerging contaminants (i.e., tetracycline (TET) and copper oxide nanoparticles (CuO-NPs)) has raised wide concerns about their potential impacts on the efficiency of wastewater treatment. However, the joint effects of TET and CuO-NPs on activated sludge processes have rarely been documented. This study investigated the sludge characteristics and bioactivities under both individual and joint exposure to TET (1 mg/L) and CuO-NPs (2 mg/L) for 60 days. The results demonstrated that both individual and joint exposures of TET and CuO-NPs deteriorated the flocculation ability and dewatering of sludge by inducing non-filamentous bacteria. The joint exposure showed higher effects on sludge when compared with individual exposure. Sludge characterization analysis attributed this deterioration partly to the increased extracellular polymeric substance (EPS) secretion (especially loose-bound EPS). In addition, exposure to CuO-NPs would result in an inhibition of total nitrogen removal due to impairment of the denitrification process (i.e., nitrate reductase, nitrous reductase, and electron-transfer associated enzyme), but not for TET. The inhibition of nitrogen removal could be exacerbated when simultaneously exposed to CuO-NPs and TET. 16S rRNA analysis further revealed that the long-term joint exposure to TET and CuO-NPs resulted in a significant decrease in microbial community richness, diversity, and associated functional bacteria abundance. The results of this study suggest that joint exposure to TET and CuO-NPs results in the deterioration of sludge function efficiency.

Performance Assessment of Confined Tube Aerators in Parallel Configuration

Aeration plays a major role in the activated-sludge wastewater treatment process. Microbes require an oxygen-enriched environment to digest organic materials and remove nutrients from the wastewater stream. For providing this oxygen, artificial aeration is required, which is responsible for the majority of energy use in treatment plants. Typically, this is accomplished with diffused aerators, where pressurized air is forced through a porous medium at the bottom of deep basins, and bubbles float up through the water column transferring oxygen in the process. This is a relatively energy-intensive process, which is prone to fouling at the porous media. In this study, a Confined Tube Aeration (CTA) system is proposed, where a pump forces water through a Venturi injector, where air is naturally drawn in. At the Venturi discharge, the flow is diverted to a coiled tube in which oxygen transfer occurs. This study analyzes the effect of parallelizing the CTA system with multiple injectors and at varying pump speeds (flow rates). Using experimental and analytical means, the maximum standard aeration efficiency was found to be with three injectors in parallel, at maximum pump speed, and utilizing a CTA with diameter 31.75 mm and length 3.048 m. This value was found to be 0.542 kg O2/kWh, and represents a 25% increase over the single-injector case. Although the analyses herein utilize a relatively small (0.746 kW) pump, these results indicate that CTA systems may scale well to larger pump sizes necessary for full-scale municipal wastewater treatment.

Microbial community dynamics in different floc size aggregates during nitrogen removal process upgrading in a full-scale landfill leachate treatment plant

Upgrading processes to reduce biodegradable organic substance addition is crucial for treating landfill leachate with high pollutant concentrations, aiding carbon emission reduction. Aggregate size in activated sludge processes impacts pollutant removal and sludge/water separation. This study investigated microbial community succession and driving mechanisms in different floc-size aggregates during nitrogen removal progress upgrade from conventional to partial nitrification–denitrification in a full-scale landfill leachate treatment plant (LLTP) using 16S rRNA gene sequencing. The upgrade and floc sizes significantly influenced microbial diversity and composition. After upgrading, ammonia-oxidizing bacteria were enriched while nitrite-oxidizing bacteria suppressed in small flocs with homogeneity and high mass transfer efficiency. Larger flocs enriched Defluviicoccus, Thauera, and Truepera, while smaller flocs enriched Nitrosomonas, suggesting their potential as biomarkers. Multi-network analyses revealed microbial interactions. A deep learning model with convolutional neural networks predicted nitrogen removal efficiency. These findings guide optimizing LLTP processes and understanding microbial community dynamics based on floc size.

Strategies for Removing Endocrine Disrupting Chemicals (EDCs) from Wastewater.

Endocrine-disrupting drugs, also called endocrine disruptors or micropollutants, cause serious environmental and public health problems due to their ability to disrupt the endocrine functions of organisms and humans, even at low concentrations. This report provides a summary of current removal techniques, such as activated sludge processes, membrane filtration, adsorption, and membrane bioreactor techniques for endocrine-disrupting chemicals, including their efficiency, limitations, and practical implementation. This review evaluates these methods by considering their treatment efficiency, costs, and environmental impact. To curb this menace, several developed countries have distinct strategies, such as physical remediation techniques, biological processes, phytoremediation, and chemical processes to remove endocrine disruptors. In developing nations, most conventional wastewater treatment plants do not even monitor those contaminants due to the low biodegradability and high complexity of such compounds. Hence, in this review work, potential endocrine-disrupting chemicals, their impacts, mechanisms of action, consequences for human health, and bio-mitigation strategies reported so far have been discussed in the context of the relevant literature.

Life Cycle Impact Assessment (LCIA), A Decision Making Approach in Waste Water Treatment Plant: A Case Study

Environmental foot print of a waste water treatment plant is an important criterion to assess the performance of treatment unit. The novel waste water treatment technology was used to clean waste water up to a certain limit. Therefore, in whole process, beginning from electricity production to final disposal of water these treatment technologies can affect our environment. This environmental foot print can be determined by using CML 2000 guideline. In final performance of a waste water treatment plant environmental ill effects should also be incorporated instead of only using treatment efficiency, CML 2000 gives environmental performance. In this study four waste water treatment technologies namely Activated Sludge Process, up flow Anaerobic Sludge Blanket, Membrane Biofilm Bioreactor, Fluidized Aerobic Bed were taken. The environmental performance of all these novel technologies was assessed on the basis of eutrophication, global warming potential and removal efficiency, characterization factors are normalized by using CML 2000 guideline. The maximum and minimum results of Acidification was obtained as 0.2215 &amp; 0.0569 in UASB and FAB respectively. The maximum and minimum results of Eutrophication was attained as 0.564 &amp; 0.055 in MBBR and ASP respectively.

Synergic treatment of domestic wastewater and food waste in an anaerobic membrane bioreactor demo plant: Process performance, energy consumption, and greenhouse gas emissions

Ambient operation and large-scale demonstration have limited the implementation and evaluation of anaerobic membrane bioreactors (AnMBRs) for low-strength wastewater treatment. Here, we studied these issues at an AnMBR demo plant that treats domestic wastewater and food waste together at ambient temperatures (7–28 °C). At varied hydraulic retention times (HRTs, 8–42 h), the AnMBR achieved a COD removal efficiency and biogas production of 80.4% ± 3.9% and 66.5 ± 9.4 NL/m3-Influent, respectively. Moreover, a stable high membrane flux of 14.4 L/m2/h was reached. The electric energy consumption for the AnMBR operation was 0.269–0.433 kW·h/m3, and 49.4%–91.3% could be compensated by the electric energy produced from methane production. At an HRT of 10 h, the AnMBR system demonstrated an impressively low net electric energy consumption of merely 0.05 kW·h/m3, resulting in a net greenhouse gas emission of 0.015 CO2-eq/m3, cutting 85% compared to the conventional activated sludge process. Achievements in this study provide key parameters for the ambient operation of AnMBR and demonstrate that AnMBR is an energy-saving and low-carbon solution for low-strength wastewater treatment.

Experimental Investigation on Photocatalytic Degradation of Refractory Organics in Biologically Treated Tannery Effluent Using Photocatalysis

There is a pressing demand for the introduction of environmentally safe technologies for the industries that supply the basic needs of industrialized societies. Advanced Oxidation Processes may become one of the answers to these uprising pollution management problems in the near future. The present investigation aimed to reduce the refractory organics present in the biologically treated (Activated Sludge Process) tannery effluent using Photocatalysis. The optimum time, pH, dosage of H2O2, and mass of NPAC required for the effective treatment using photocatalysis were found to be 60 mins, 8, 0.2 mg.L-1, and 1g. 100 mL-1, respectively. Although the efficiency of homogeneous photocatalysis was found to be higher than that of heterogeneous photocatalysis, the biodegradability was higher in the latter, with a value of 0.26. The experimental results have proved that photocatalysis could be a promising technology to reduce the refractory organics present in the tannery effluent.

Impact of N loading on Microbial Community Structure and Nitrogen Removal of an Activated Sludge Process with Long SRT for municipal wastewater treatment

Biological nutrient removal process is pivotal in controlling nitrogen and phosphorus from municipal wastewater treatment and reclamation plants in the water environment. The efficiency of municipal wastewater treatment is affected by the fluctuation of influent quality. In this study, the impact of N loading on the removal efficiency and the microbial community structure of activated sludge with long sludge retention time were investigated. The results showed that the effluent NH4+-N and NO2--N concentration were lower than 0.5 mg/L, and the TN removal efficiencies were 79.77% and 65.80%, respectively. The dehydrogenase activity, specific oxygen uptake rate, specific nitrification rate, and specific denitrification rate increased as the N loading increasing. At the phylum level, the most dominant bacterial was affiliated with Proteobacteria in the two systems, accounting for 60.65% and 48.62%, respectively. At the genus level, Acinetobacter, Thauera, and Zoogloea played significant roles in denitrification. The ammonia oxidation bacteria and nitrite-oxidizing bacteria were of the genus Nitrosomonas (r-strategist) and Nitrospira (K-strategist).

Reducing sludge formation by enhancing biological decay of biomass: a mathematical model

Abstract We investigate a model for an activated sludge process that contains a chemical reactor unit attached to a bioreactor. Inside the chemical reactor unit, a process takes place which increases the decay coefficient of heterotrophic biomass. This mimics a number of experimental techniques which are used to decrease the mass of sludge. Such techniques are of growing interest as the activated sludge process produces large volumes of sludge; the costs associated with its disposal are significant. Our primary interest is to investigate how the operation of the chemical reactor unit changes the steady-state concentrations of both the total suspended solids within the biological reactor and the chemical oxygen demand in the effluent stream. The operation of a chemical reactor unit always increases the value of chemical oxygen demand in the effluent stream. The behaviour of the total suspended solids is more complicated; in some cases, the operation of the CRU increases the total suspended solids. For a fixed value of the chemical oxygen demand in the influent stream, we show that both the percentage reduction in the total suspended solids and the chemical oxygen demand in the effluent stream are increasing functions of the soluble substrate in the feed. The same trends occur when the influent composition is fixed, and the disintegration rate inside the chemical reactor unit is increased. This leads to dichotomic behaviour, decreasing the total suspended solids increases the chemical oxygen demand in the effluent stream. There are two consequences of this behaviour. Firstly, there are some waste streams that can not be cleaned using the process configuration considered in this paper. Secondly, the imposition of a target value for the chemical oxygen demand in the effluent stream imposes a maximum achievable reduction in the total suspended solids in the biological reactor. Higher reductions can not be achieved without causing the chemical oxygen demand in the effluent stream to exceed the target value.

Enhancing the performance of microalgal-bacterial systems with sodium bicarbonate: A step forward to carbon neutrality of municipal wastewater treatment

The microalgal-bacterial granular sludge (MBGS) process, enhanced with sodium bicarbonate (NaHCO3), offers a sustainable alternative for wastewater treatment aiming for carbon neutrality. This study demonstrates that NaHCO3, which can be derived from the flue gases and alkaline textile wastewater, significantly enhances pollutant removal and biomass production. Optimal addition of NaHCO3 was found to achieve an inorganic-to-organic carbon ratio of 1.0 and a total carbon-to-nitrogen ratio of 5.0. Metagenomic analysis and structural equation modeling showed that NaHCO3 addition increased dissolved oxygen concentrations and pH levels, creating a more favorable environment for key microbial communities, including Proteobacteria, Chloroflexi, and Cyanobacteria. Confocal laser scanning microscopy further confirmed enhanced interactions between Cyanobacteria and Proteobacteria/Chloroflexi, facilitating the MBGS process. These microbes harbored functional genes (gap2, GLU, and ppk) critical for removing organics, nitrogen, and phosphorus. Carbon footprint analysis revealed significant reductions in CO2 emissions by the NaHCO3-added MBGS process in representative countries (China, Australia, Canada, Germany, and Morocco), compared to the conventional activated sludge process. These findings highlight the effectiveness of NaHCO3 in optimizing MBGS process, establishing it as a key strategy in achieving carbon-neutral wastewater treatment globally.

Effectiveness of natural herbs on sewage and treated municipal wastewater: A comparative study

Improperly handled sewage is the main cause of water pollution. Nearly 62% of wastewater in urban India remains untreated or partially treated, which further gets disposed of in the natural water bodies. The usual treatment methods include the activated sludge process, oxidation ponds, aerated lagoons, and trickling filters. These methods need spacious areas, a lot of energy and time, which drives up the cost of the treatment. The expense of the treatment process can be decreased by using natural coagulants. The indigenous medical system uses plants, which are abundant in secondary metabolites, to treat a variety of illnesses. The purpose of this study was to comprehend how these indigenous plants can be utilized for treating sewage water, as a low-cost accessible method that can be used by citizens to get access to clean drinking water. Material &amp;amp; Methods: A quick and low-cost method was created to investigate the efficacy of Moringa oleifera (Moringa), Ocimum sanctum (Tulsi), and Azadirachta indica (Neem) in the treatment of sewage water. This herb treated water was then compared to municipal treated water from the Ghatkopar Wastewater treatment facility, managed by the Municipal Corporation of Greater Mumbai (MCGM), Mumbai, India. All the herb-based components were bought from regional markets, and water samples from a lagoon found in the nearby Ghatkopar lagoon in Mumbai. Results: When compared to the lagoon-treated water, the efficacy of the sewage water treated with herbs was higher or comparable. Coliform and copper levels decreased considerably in the treated sample. Herb-treated samples showed a reduction in the Chemical Oxygen Demand (COD) levels as compared to the treated water. Conclusion: When combined, the herbs had a significant impact on lowering the COD, Copper, and coliform levels, making the native plants a valuable source for the treatment of sewage water.

Flexible supply-demand side management towards a sustainable decentralized distribution network: A net-negative Water-energy-emissions Nexus assessment

Severe water and energy shortfalls hinder widespread access and challenge sustainable resource management in various supply systems. This study proposed a new decentralized distribution network with net-negative emissions concept and flexible strategies to ensure efficient water and mix-energy with low-carbon emissions The proposed net-negative water-energy emission decentralized distribution network (N-NWEE-D2N) was formulated by assessing spatio-temporal interactions at local-regional scale of multi-sector water and energy demand and supply using flexible nexus regulation strategies. The feasibility of self-production and CO2-based regeneration from biogas recovery in activated sludge process and non-renewable energy generation, respectively, was investigated. The N-NWEE-D2N-based water-energy distribution showed an effective balance between supply and demand, with low deficits, efficient surplus utilization, and reduced CO2 emissions. The water and energy management efficiencies based on N-NWEE-D2N improved by 67.196% and 78.11%, respectively, compared to scenarios without such considerations, due to the effective decentralized distribution of water and energy among the regions. Thus, proposed N-NWEE-D2N can contribute to the sustainable operation of WWTPs and promoting long-term sustainability in water and energy distribution transmission.

Electrochemical treatment of 4-chlorophenol by three-dimensional electrode reactors packed with plastic particles electrodes

The three-dimensional electrode reactors (TDER) filled with surface-modified plastic particles electrodes, was much more effective on electrolyzing 4-chlorophenol wastewater than by conventional electrolysis. The experimental results indicated that about 96.8 % of 4-chorophenol was degraded effectively, it was possibly decomposed into aromatic organic compounds and small-molecular organic acids by hydroxyl radicals generated on the surfaces of electrodes, and the biodegradability of treated 4-chlorophenol wastewater was also much more improved than that of the untreated, which would be more easily biologically degraded by the subsequent conventional activated sludge process. Furthermore, the 4-chorophenol wastewater could be co-degraded with high-concentration nitrate effectively, both 2-chlorophenol and 2,4-dichorophenol wastewaters were also similarly decomposed.

Biofilm Reactors: A Potential Alternative to Current Treatment Technology for Wastewater in Kathmandu Valley

Kathmandu Valley faces challenges managing its growing wastewater volume, compounded by the complex composition of unregulated industrial discharges. Releasing untreated wastewater poses a severe risk to public health and the environment. Existing wastewater treatment infrastructure, primarily reliant on conventional activated sludge processes (ASP) struggles to meet growing demands. These systems require substantial land area, are sensitive to influent variations, produce a high volume of sludge, and incur high operational and maintenance costs. Biofilms, naturally occurring assemblages of microorganisms adherent to surfaces and embedded within an extracellular polymeric matrix (EPS), present a compelling alternative for wastewater treatment due to their diverse pollutant removal capabilities. When implemented as biofilm reactors, they offer distinct advantages, including tolerance to fluctuations in wastewater composition, minimal land requirements, and reduced energy consumption. Notably, microbes residing within a biofilm are capable of biodegradation of persistent materials such as pharmaceuticals, metals, and plastics. Globally, biofilmmediated wastewater treatment has been implemented successfully, while a knowledge gap remains for the treatment of Kathmandu's wastewater. This review critically assesses biological wastewater treatment methods, providing insight into: a) suspended growth process with their configuration, application, and limitations, b) wastewater treatment infrastructures of Kathmandu Valley, and c) biofilm process with their configuration, factors influencing biofilm development and performance, application of specific microbial strains for enhanced treatment efficiency, and factors to be considered during implementation. Furthermore, the paper recommends: a) an extensive study of laboratory-scale biofilm reactors evaluating and optimizing their performance for local integration and b) investigating the role of diverse microbial communities to further enhance the treatment plant's operation. By prioritizing research and development towards biofilm technology, Kathmandu Valley can achieve efficient and environmentally friendly wastewater management.

Unified control of diverse actions in a wastewater treatment activated sludge system using reinforcement learning for multi-objective optimization

The operation of modern wastewater treatment facilities is a balancing act in which a multitude of variables are controlled to achieve a wide range of objectives, many of which are conflicting. This is especially true within secondary activated sludge systems, where significant research and industry effort has been devoted to advance control optimization strategies, both domain-driven and data-driven. Among data-driven control strategies, reinforcement learning (RL) stands out for its ability to achieve better than human performance in complex environments. While RL has been applied to activated sludge process optimization in existing literature, these applications are typically limited in scope, and never for the control of more than three actions. Expanding the scope of RL control has the potential to increase the optimization potential while concurrently reducing the number of control systems that must be tuned and maintained by operations staff. This study examined several facets of the implementation of multi-action, multi-objective RL agents, namely how many actions a single agent could successfully control and what extent of environment data was necessary to train such agents. This study observed improved control optimization with increasing action scope, though control of waste activated sludge remains a challenge. Furthermore, agents were able to maintain a high level of performance under decreased observation scope, up to a point. When compared to baseline control of the Benchmark Simulation Model No. 1 (BSM1), an RL agent controlling seven individual actions improved the average BSM1 performance metric by 8.3 %, equivalent to an annual cost savings of $40,200 after accounting for the cost of additional sensors.