Hospital wastewater (HWW) carries a high and variable burden of pathogenic microorganisms, along with a diverse spectrum of emerging contaminants, such as pharmaceutically active compounds (PhACs) and antimicrobial resistance (AMR) determinants, posing significant challenges to conventional municipal treatment systems. The COVID-19 pandemic intensified the global use of disinfection technologies for infection control, inadvertently leading to the generation and release of novel classes of disinfection by-products (DBPs) and transformation products (TPs). These emerging by-products, alongside the persistent release of pharmaceuticals and AMR elements, have exposed critical limitations in conventional and advanced disinfection processes when applied to such complex matrices. This review synthesizes recent literature on disinfection-oriented advanced treatment strategies and other contaminants of emerging concern in hospital effluents worldwide. The discussed technologies include chlorine-based disinfection (e.g., free chlorine and chlorine dioxide), ozonation, ultraviolet irradiation (UV), electrochemical disinfection (ECD), nanomaterial-enabled disinfection, and combined multi-barrier schemes. While real-time monitoring of key compounds in HWW is increasingly feasible, critical bottlenecks remain: culture-based indicators may underestimate viable but non-culturable populations, molecular assays quantify genes without directly reflecting infectivity or transfer potential, and complex matrices hinder methodological harmonization. Future efforts should prioritize risk-based multi-barrier design, activity-informed monitoring, and intelligent process control to achieve robust co-mitigation of pathogens, PhACs, and AMR while minimizing disinfection by-products (DBPs) and life-cycle energy consumption.

This study explores a circular bioeconomy strategy for microbrewery waste by characterizing and valorizing its primary waste streams: sugar mash water (A), spent yeast with hops (B), spent yeast without hops (C), and alkaline cleaning wastewater (D). The biochemical methane potential of the acidic organic blend (E, from A-C) was assessed under mesophilic (38 °C) and thermophilic (55 °C) conditions, revealing significant substrate-specific temperature sensitivity. The highly acidic blend E (pH 4.16) was effectively neutralized to pH 7.0 using the on-site alkaline wash water (D, pH 12.03). Mesophilic anaerobic digestion of the neutralized blend achieved a high methane yield of approximately 500 mL/g VS. Furthermore, the alkaline wash water successfully served as an in situ CO2 scrubber, upgrading biogas to ~100% methane content. This integrated approach demonstrates a viable, closed-loop pathway for microbreweries to achieve simultaneous energy recovery from organic wastes and chemical-free treatment of acidic and alkaline effluents. The findings also highlight the importance of substrate-specific thermal management and provide a robust framework for microbreweries to achieve energy independence and internal CO2 neutralization–wastewater treatment.

This study investigates a novel method for synthesizing nitric acid (HNO3) from air using a 10-kW microwave induction-coupled plasma torch. The experimental setup integrated a plasma torch, gas residence columns (oxidizing columns), and water absorption columns containing 60 L of water. Therefore, various torch operation durations (i.e., 30, 60, 90, and 300 min) and gas replenishment intervals were evaluated. Notably, the reaction rate decreased significantly when the oxygen concentration in the oxidizing columns dropped below 6%, rendering continuous torch operation inefficient. Importantly, after the torch was deactivated, HNO3 formation persisted, highlighting the importance of absorbing residual NOx in the liquid phase. The highest yield was achieved by operating the torch for 60 min, followed by 30 min of gas recirculation and replenishment, resulting in a maximum HNO3 concentration of 0.162 M and an energy consumption of 6.82 MJ per mole.

Tofu wastewater is a nitrogen-rich wastewater type with a high concentration of organic contents. To enhance the digestion rate of tofu wastewater in an anaerobic bioreactor, water hyacinth was tested as an additional substrate. Water hyacinth is a dangerous weed with a high carbon-nitrogen ratio (C/N) of about 30-35. Substrate combination was intentionally used in this study to raise the C/N of wastewater. This study aims to evaluate the digestion rate of a bioreactor qualitatively based on experimental data to determine the biokinetic constants of the anaerobic bioreactor quantitatively based on microbial growth data, substrate degradation, and methane (CH4) production. MATLAB was used as software to run mathematical modeling. The anaerobic bioreactor was designed and equipped with a circulation pump to maintain the homogeneity of the substrate and was completed with a biogas collector. Seeding and acclimatization were carried out before the main experiment started. Using a combination substrate of tofu wastewater and water hyacinth with a 5:3 volume ratio, the bioreactor was run at 20 days of hydraulic retention time (HRT) at room temperature. The bioreactor was able to remove 92.8% of chemical oxygen demand (COD) concentration and produced biogas with the highest CH4 concentration of 56.9%. The obtained kinetic constants indicate that, in comparison with similar studies of anaerobic digestion of the low C/N wastewater, the addition of water hyacinth resulted in better performance of the bioreactor with the correlation of microbial growth rate (?m), substrate degradation (YX/CCOD) and CH4 production (YCCH4/X) with the consecutive values of 0.65/day, 0.64 mg cells/mg COD, and 0.62 mg CH4/mg cells. An appropriate ratio of water hyacinth as the high carbon source and nitrogen-rich tofu wastewater is recommended to obtain the optimum ratio of carbon to nitrogen and result in a higher percentage of methane formation. ABSTRAK: Air sisa tauhu ialah air sisa yang kaya dengan nitrogen dengan kepekatan kandungan organik yang tinggi. Bagi meningkatkan kadar penghadaman air sisa tauhu dalam bioreaktor anaerobik, keladi bunting diuji sebagai substrat tambahan. Keladi bunting merupakan rumpai berbahaya dengan nisbah karbon nitrogen (C/N) yang tinggi iaitu kira-kira 30-35. Gabungan substrat sengaja digunakan dalam kajian ini bagi menaikkan C/N air sisa. Kajian ini bertujuan bagi menilai kadar pencernaan bioreaktor secara kualitatif berdasarkan data eksperimen dan menentukan pemalar biokinetik bioreaktor anaerobik secara kuantitatif berdasarkan data pertumbuhan mikrob, degradasi substrat, dan pengeluaran metana (CH4). MATLAB digunakan sebagai perisian pemodelan matematik. Bioreaktor anaerobik direka bentuk dan dilengkapi dengan pam edaran bagi mengekalkan kehomogenan substrat dan dilengkapkan dengan pengumpul biogas. Penyemaian dan penyesuaiikliman telah dijalankan sebelum eksperimen utama bermula. Substrat gabungan air sisa tauhu dan keladi bunting digunakan dengan nisbah isipadu 5:3. Bioreaktor dijalankan selama 20 hari iaitu masa pengekalan hidraulik (HRT) pada suhu bilik. Bioreaktor tersebut mampu mengasingkan 92.8% kepekatan permintaan oksigen kimia (COD) dan menghasilkan biogas dengan kepekatan CH4 tertinggi sebanyak 56.9%. Pemalar kinetik yang diperoleh menunjukkan bahawa, berbanding dengan kajian serupa tentang pencernaan anaerobik air sisa C/N rendah, penambahan keladi bunting menghasilkan prestasi bioreaktor yang lebih baik dengan korelasi kadar pertumbuhan mikrob (?m), degradasi substrat (YX/CCOD) dan penghasilan CH4 (YCCH4/X) dengan nilai masing-masing 0.65/hari, 0.64 mg sel/mg COD, dan 0.62 mg CH4/mg sel. Nisbah keladi bunting yang sesuai sebagai sumber karbon tinggi dan air sisa tauhu yang kaya dengan nitrogen disyorkan agar mendapatkan nisbah optimum karbon kepada nitrogen dan ini menghasilkan peratusan pembentukan metana yang lebih tinggi.

This research aims to check the chargeability of sodium hypochlorite and the efficacy evaluation of an airassisted electrostatic disinfection device. Five different inanimate surfaces i.e., wood, glass, stainless steel, plastic and fabric were considered to examine the performance in terms of efficacy, survival time, off-target losses, spray coverage and the volume of disinfectant consumed. A significant charge-to-mass level of 2.43 mC/kg was achieved for sodium hypochlorite at an applied voltage of 2.0 kV, a liquid flowrate of 253 ml/min and applied air pressure of 4.0 bar. The experimental results found that 1000 mg/L of sodium hypochlorite concentration effectively eliminated Pseudomonas aeruginosa, Clostridium perfringens and Bacteriophage MS2 colonies.

Training is one of many activities to improve the competencies of employees. Politeknik Negeri Bandung conducted wastewater treatment training for teachers from one of the vocational high schools in Bandung, Indonesia. To analyze the parameters influencing the training effectiveness of its training, this study employed quantitative research. Data regarding the demographics of respondents and respondents’ perceptions about various parameters influencing the training effectiveness were gathered by a survey questionnaire. In addition, the paper-based final test was used to identify the understanding of trainees about the content provided, and further, the data was used for analyzing training effectiveness. The data were then analyzed by using the statistical package for social sciences software. The findings suggested that the respondents have positive perceptions of training materials, training atmosphere, training facilities, training plan and schedule, and presentation mode. The average value of the Likert scale ranges from 3.33 to 3.89 of 4. It reflected that wastewater treatment training satisfied the trainee’s expectations from their point of view. Additionally, a positive linear correlation between the dependent parameter (training effectiveness) and five independent parameters could be inferred. The results of the study are valuable in encouraging organizations that hold training to take these parameters into account when carrying out similar training.

The increase in population in Indonesia is directly proportional to the increase in the use of vehicles which results in an increase in fuel demand. The amount of fossil fuels continues to decrease and cannot be renewed, so alternative energy is needed, one of which is bioethanol. This study aims to make bioethanol from banana weevil waste, to determine the effect of fermentation time on the concentration of banana weevil bioethanol and to determine the concentration of bioethanol after going through the purification stage. The production of banana weevil bioethanol begins with the process of cutting the banana weevil which is then mashed with the help of water and then squeezed and starch is obtained and then hydrolyzed with the addition of glucoamylase and alpha-amylase enzymes for further anaerobic fermentation with the help of Saccharomyces cerevisiae with a concentration of 25%. In this study, variations of fermentation time were carried out for 5, 7, 9, and 10 days. The best fermentation time was obtained from 9 days of fermentation, where the conversion of glucose to bioethanol was 51%. The results of the analysis using a refractometer showed that the concentration of bioethanol obtained was 16.20% (v) which was obtained from fermentation for 9 days and purification using a rotary evaporator at a pressure of 360 mbar and a temperature of 500C.

Anaerobic digestion is widely used for waste treatment and biofuel production in the form of biogas from dedicated energy crops. Proper operation and control of anaerobic digesters require knowledge of biogas flow rate and methane composition of biogas. Methane content of biogas from an anaerobic digester was measured on-line by modifying an off-line measurement device, previously constructed by the authors, that uses a hydrocarbon sensor (MQ-4) and a pressure/temperature/humidity sensor (BME-280) integrated with an Arduino Uno. This modified on-line sensor was programmed to automatically measure methane composition by self-regulated introducing biogas samples and evacuating the device. It is also equipped with a function of biogas flowmeter which could calculate the cumulative biogas production over a time interval. Methane composition (v/v) could be measured every three hours. Measurements made by this device agreed within an average absolute difference of 0.81 ± 0.58

Anaerobic digestion is widely used for waste treatment and for biofuel production in the form of biogas from dedicated energy crops. Proper operation and control of anaerobic digesters require knowledge of biogas flow rate and methane composition of biogas. Methane content of biogas from an anaerobic digester was measured on-line by modifying an off-line measurement device, previously constructed by the authors, that uses a hydrocarbon sensor (MQ-4) and a pressure/temperature/humidity sensor (BME-280) integrated with an Arduino Uno. This modified on-line sensor was programmed to automatically measure methane composition by self-regulated introducing biogas sample and evacuating the device. It also equipped with a function of biogas flow chamber which could calculate the cumulative biogas production over a time interval. Methane composition (v/v) could be measured every three hours. Measurements made by this device agreed within an average absolute difference of 0.81 ± 0.58 % with measurements by a gas chromatograph equipped with a thermal conductivity detector. The volumetric flow rate was directly expressed on a moisture-free basis at standard temperature and pressure. The total cost of this device was under US $140. For an additional US $7, the device can be upgraded with an LED display that toggles between composition and flow rate.

Anaerobic digestion of municipal solid waste (MSW) is a controlled process of microbial decomposition where a consortium of microorganisms convert organic matter into methane, carbon dioxide, inorganic nutrients, and humus. In a generalized scheme for anaerobic digestion, feedstock is harvested or collected, coarsely shredded, and placed into a reactor which has an active inoculum of microorganisms required for the methane fermentation. This chapter reviews the status of anaerobic digestion as applied to MSW. It discusses principles of the microbiology of biomethanogenesis and their application in the design, operation, and evaluation of the anaerobic digestion process. The predominant hydrolytic microorganisms in rumen differ from anaerobic digestion systems. Anaerobic digestion models can be used for optimizing process design and operation and for process control. The starting point for developing a process model for anaerobic digestion is developing mass balance equations which account for the changes in concentration of the substrates, microbial populations, and products during the course of the digestion process.

Polylactic acid polymer (PLA) produced from renewable resources can be recycled at the end of life to constituent monomer, optically pure lactic acid (LA), by a combination of chemical and biological processes. Efficient application of this closed loop of LA-PLA plastics-LA can minimize accumulation of plastics waste that pollute land and oceans. Temperature-dependent hydrolysis of PLA in water to LA follows apparent first order decay kinetics after a short lag. A modified Gompertz equation can explain the overall hydrolysis process. Alkali increased the rate of hydrolysis of PLA and reduced the length of lag period compared to water alone. The stoichiometry of base added to LA released was 1.0. The highest lactic acid yield was 0.95 g g−1 of PLA. d-LA in the syrup obtained after hydrolysis of PLA-plastics was removed using an engineered Escherichia coli to produce a l-LA syrup with an optical purity ≥ 99%. These results show that thermochemical hydrolysis of PLA-based plastics to LA with optimum amount of base followed by bio-based purification to l-LA is an effective method of recycling PLA-plastics for reuse.

Convenient energy sources like biomethane and electricity are scarce commodities in cassava producing countries that depend on wood and charcoal for energy supply. Combustion of wood and charcoal releases substances that impair human health. In 2016, about 30 million metric tons of cassava peeling residues (CPR) were generated worldwide and discharged into the environment. Apart from deforestation, loss of biodiversity and soil erosion caused by felling vegetation for wood and charcoal recovery, discharge of CPR into the environment exacerbates environmental pollution and health hazards. This study presented biogasification experiments with CPR in a simple, batch, leach‐bed, unmixed fermentor. Biofuel yield ranged from 180 to 310 (mean of 252) L CH4 kg−1 VS−1 while fermentation time ranged from 19 to 33 (mean of 27) days. The substrate contained on average 33% dry matter of which 96% was volatile, and 71% volatile solids reduction was achieved. Furthermore, all electrical and thermal energy required for producing three cassava root food products (flour, gari, and starch) could be generated on‐site using CPR as substrate for anaerobic digestion. Consequently, energy paucity, environmental contamination, health hazards associated with cassava processing effluent, and combustion of wood and charcoal, could be mitigated by biogasification of CPR. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13138, 2019

An inexpensive, portable device to measure methane content of biogas samples was constructed. The central component of the device was an MQ-4 methane sensor. This sensor, along with humidity, temperature and pressure sensors, was enclosed in an airtight glass jar and interfaced with a programmable Arduino Uno clone for data logging and operation. The sensor was able to detect methane within the jar to as low as 400 ppm, but responded linearly to concentrations ranging from about 4000 to 110,000 ppm. Measurements made by the sensor were compared to analysis by a gas chromatograph equipped with a thermal conductivity detector. Analysis of biogas samples from an anaerobic digester using the device produced an average absolute error of 0.69+/-0.55% when compared to GC measurements. Using 10 ml biogas sample size, methane content as low as 18% by volume could be reliably measured by the device. By increasing sample to 90 ml, methane content as low as 2.4% could be analyzed. This device was assembled for a cost of US$37. A field version that includes an LED display and power pack could be assembled for under US$50. (C) 2019 Elsevier Ltd. All rights reserved.

This multi-institutional project had as it main objectives to develop a fully integrated platform for the production of advanced biofuels, specifically butanol, from sustainably produced switchgrass and biomass sorghum and to develop economic models that could guide the establishment of a crop to fuel value chain. The project was organized into three work packages: (1) WP1 Feedstock Development and Supply. Activities in this WP resulted in the development of improved biomass sorghum cultivars and biomass hybrids that generate high yields of biomass with limited inputs of water, fertilizer and agri-chemicals and that display less recalcitrance to enzymatic saccharification at the biorefinery; the identification of physiological responses and genes associated with sorghum’s tolerance to water logging as the basis for the development of biomass sorghums that can be cultivated on land prone to flooding; the identification of water-logging tolerant switchgrass genotypes among existing germplasm; the identification of management practices that maximize switchgrass biomass yield (fertilizer applications, harvest regimens) on commercial farms on different types of soil in Missouri. (2) WP2 Biorefinery Technologies. This WP included the development of a recombinant E. coli strain able to convert fermentable sugars derived from biomass sorghum and switchgrass to butyrate as a precursor for the advanced biofuel butanol. Butanol is toxic to most microbes, so that yields tend to be low. In contrast, butyrate can be produced in high titer and high yield by several naturally occurring bacteria, but these species are strictly anaerobic, which complicates commercial production. Our strategy involved developing a recombinant strain of E. coli able to produce high yields and high titers of butyrate. The butyrate can then be reduced to butanol via chemical conversion. In addition, a techno-economic analysis of converting sorghum and switchgrass biomass to ethanol was conducted based on data obtained at a pilot biorefinery. These data combined with small-scale butanol production data were used as the basis for a techno-economic analysis of biomass-to-butanol conversion. Furthermore, the biorefinery stillage was evaluated as a source of fertilizer or soil amendment. In contrast to the use of biochar as a soil amendment, stillage resulted in enhanced microbial activity in the soil and release of CO2. Stillage was determined to be a suitable feedstock for biogas production in an anaerobic digester. Biorefinery lignin can be blended with polymers to create novel UV-resistant materials promising for application in outer space, and as a source of organic acids for use in plastics. These applications offer opportunities to create value from the biorefinery residues. (3) WP3. This WP focused on development of economic models that can help define the most successful strategy for implementing biofuel production from bioenergy crops. Southeastern Missouri was determined to be the best location for a bio-butanol facility that processes biomass crops, due to the abundance of feedstock within a small radius of the facility. The most effective transportation method is by rail car. Feedstock availability was considered a more important driver for commercial success than the availability of a butanol market. The average cost of producing switchgrass biomass was calculated to be $65/ton assuming a biomass yield of 8 tons per hectare (the upper end of the yield in the commercial trials in WP2). Lower yields drive up costs, but improved genotypes will conversely reduce costs. Based on farmer surveys, conducting university extension activities was determined to positively influence farmers’ willingness to consider switchgrass. Other factors included experience with pasture land and forest land, and the availability of policies that provide a safety net to the farmers in case of instability in the biofuels market. This instability can be mitigated in part by ensuring adequate biomass supplies through diversification. The project supported the training of 20 graduate students and resulted in 57 peer-reviewed journal articles (with eight additional in review or in progress), eight book chapters and five patents.

The current work presents an experimental procedure to determine the mechanical characteristics of individual biomass particulate materials, including comparatively spherical olive pulp particles and hollow cylindrical hay particles. This study also provides a comparison between the mechanical characteristics of wet and dry olive pulp particles. The strength and elastic properties of olive pulp particles were measured by conducting an uniaxial compression tests. For hay particles, the properties were measured by conducting compression tests in axial and radial directions, and three-point bending tests. The analysis of radial compression tests with hollow cylindrical particles was introduced in this paper, using the theory underlying the analysis of curved beams subjected to bending. The results indicated that small soft olive pulp particles are stronger and stiffer than large particles, and that wet olive pulp particles are weaker and softer than dry particles.

Microalgae are a promising feedstock for bioenergy due to higher productivity, flexible growing conditions, and high lipid/polysaccharide content compared to terrestrial biomass. Microalgae can be converted to biogas through anaerobic digestion (AD). AD is a mature technology with a high energy return on energy invested. Microalgae AD can bypass energy intensive dewatering operations that are associated with liquid fuel production from algae. A techno-economic assessment of the commercial feasibility of algae-based biogas production was conducted using Cyanothece BG0011 biomass as an example. BG0011 is a naturally occurring, saline cyanobacterium isolated from Florida Keys. It fixes atmospheric nitrogen and produces exopolysaccharide (EPS). Maximum cell density and EPS concentration of 2.7 and 2.1 g afdw1/L (for total algae biomass concentration of 4.8 g afdw/L) were obtained by air sparging. For an areal cell and EPS productivity of 12.4 and 9.6 g afdw/m2/day, respectively, the biomethane production cost was 14.8 $/MMBtu using covered anaerobic lagoon and high-pressure water scrubbing for biogas purification. Electricity production from biogas costs 13 cents/kwh. If areal productivity was increased by 33% from the same system, by sparging air enriched with 1% CO2, then biomethane cost was reduced to 12.16 $/MMBtu and electricity cost to 11 cents/kwh.