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Abstract Effluent reuse is a rapidly growing field of research where assessing the quality of effluent is one of the focus areas. This research examines the viability of using wastewater in agriculture by testing an integrated Upflow Anaerobic Sludge Blanket (UASB) reactor with a trickling filter (TF) system during the dry season. Compliance monitoring was conducted for 30 days from May 11 to June 9 of 2021. Samples were collected, handled, and analyzed following standard wastewater analysis procedures for biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), volatile suspended solids (VSS), cations, anions, heavy metals, E. coli, and helminth egg. The UASB-TF system in Kality wastewater treatment performed well in removing COD, BOD5, and TSS with average removal rates of 80.5%, 82.9%, and 80.9%, respectively, compared well with similar treatment configurations. The effluent quality satisfied the national inland discharge limit with a residual concentration of 125.1 mg/L for COD, 61.7 mg/L for BOD5 and 85.8 mg/L for TSS. On the other hand, high concentrations of chromium, nitrate-nitrogen, and helminth egg count restricted effluent reuse for agricultural purposes due to high health risks and environmental contamination. We found out that discharging industrial sewage into the domestic sewer network could inhibit microbial growth and affect the biological treatment processes. Furthermore, adopting integrated treatment systems in developing countries might face operational challenges and monitoring nitrate, helminth egg, and heavy metals would help provide timely operational feedback. An appropriate tertiary treatment unit—constructed wetlands or polishing ponds—is therefore needed to be introduced to ensure effluent reuse for agricultural purposes.

The purification of biogas as a product of anaerobic digestion has gradually become a research focus. In situ hydrogen-assisted biogas purification is an effective way to enhance the reaction rate, but the solubility and mass transfer efficiency of hydrogen are the difficulties that constrain the technology. Thus, four continuous hydrogen injection modes M1: 1 mL/min, M2: 2 mL/min, M3: 5 mL/min, and M4: 10 mL/min and two intermittent hydrogen injection modes A: 4 mL/min (interval 20 min) and B: 6 mL/min (interval 40 min) were designed to explore the effect of different hydrogen injection modes on in situ biogas upgrading of upflow anaerobic sludge bed (UASB) in the research. The results showed that the methane production showed a trend of increasing first and then decreasing in continuous hydrogenation experiment. The CH4 production reached its peak at 86.2% in the M2 stage. In the two batch hydrogenation tests, group A showed better hydrogenation effect with a CH4 production of about 92%, which was 4% higher than that of group B. The hydrogenotrophic methanogens (HMs) in group A archaea community were more effectively enriched, with an abundance of 52.83% of Methanobacterium. The results illustrate that proper hydrogen injection can enhance anaerobic digestion and promote biogas purification, and the effect of short-term intermittent hydrogen injection is more significant. [ABSTRACT FROM AUTHOR]

Effluent reuse is a rapidly growing field of research where assessing the quality of effluent is one of the focus areas. This research examines the viability of using wastewater in agriculture by testing an integrated Upflow Anaerobic Sludge Blanket (UASB) reactor with a trickling filter (TF) system during the dry season. Compliance monitoring was conducted for 30 days from May 11 to June 9 of 2021. Samples were collected, handled, and analyzed following standard wastewater analysis procedures for biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), volatile suspended solids (VSS), cations, anions, heavy metals, E. coli, and helminth egg. The UASB-TF system in Kality wastewater treatment performed well in removing COD, BOD5, and TSS with average removal rates of 80.5%, 82.9%, and 80.9%, respectively, compared well with similar treatment configurations. The effluent quality satisfied the national inland discharge limit with a residual concentration of 125.1 mg/L for COD, 61.7 mg/L for BOD5 and 85.8 mg/L for TSS. On the other hand, high concentrations of chromium, nitrate-nitrogen, and helminth egg count restricted effluent reuse for agricultural purposes due to high health risks and environmental contamination. We found out that discharging industrial sewage into the domestic sewer network could inhibit microbial growth and affect the biological treatment processes. Furthermore, adopting integrated treatment systems in developing countries might face operational challenges and monitoring nitrate, helminth egg, and heavy metals would help provide timely operational feedback. An appropriate tertiary treatment unit—constructed wetlands or polishing ponds—is therefore needed to be introduced to ensure effluent reuse for agricultural purposes. [ABSTRACT FROM AUTHOR]

A continuous lab-scale integrated bio-system was conducted to treat sewage wastewater from Abu-Rawash wastewater treatment plant (WWTP). The bio-system showed high efficiency in removing chemical oxygen demand (COD), biological oxygen demand (BOD5), and total suspended solids (TSS). The experimental analysis results indicated that the maximum COD removal and methane yields were 97.6 and 13.74 mmol CH4/Kg COD at a hydraulic retention time (HRT) of 6 h, respectively. Zn, Mn, and Fe were removed at a high rate of up to 96.6%. The sponge bio-carriers have improved overall treatment performance and substantially improved mixed liquor volatile suspended solids/mixed liquor suspended solids (MLVSS/MLSS) ratio at an appreciated range, and the total pathogenic organisms were removed up to 99.8% in the second stage. Because the innovative bio-system enables a rapid startup process, is simple to use, and is inexpensive, it can provide an economically feasible alternative for wastewater management and could be extended to full-scale applications for agricultural purposes. [ABSTRACT FROM AUTHOR]

Waste management in large urban centers is one of the main challenges for public administration. Two of the most abundant wastes in cities are waste solid and municipal wastewater (MWW). Their management can be optimized if they are treated together. This work analyzed an anaerobic–aerobic system for the treatment of fruit and vegetable wastes (FVWs) and MWW. Firstly, FVWs were collected and characterized; once in the laboratory, they were placed in a tank with the MWW, aiming at transferring to the water those solids with a particle size below 105 µm; then, they were separated by sieving. The mixture of MWW and FVWs with a particle size below 105 µm was fed into an up-flow anaerobic sludge reactor (UASB); in the latter, dissolved and suspended organic matter was transformed into methane and carbon dioxide. The water that left the UASB was sent to be post-treated in an activated sludge reactor (ASR). The chemical oxygen demand (COD) was used as an evaluation parameter of the anaerobic–aerobic system; a removal efficiency higher than 80% was achieved, whereas it was 60% in the ASR. Another evaluation parameter was methane (CH4) productivity, with an average of 3.0 LCH4 L−1 d−1. VWF leaching achieved an average COD extraction of 7.68 kg∙m−3. The UASB efficiency was on average 70% for the assayed loads (2–8 kg COD·L−1·d−1). The energy potential calculated for the anaerobic–aerobic system was 510.2 kW∙h∙d−1 [ABSTRACT FROM AUTHOR]

This paper aims to study dark fermentation (DF) in an upflow anaerobic sludge blanket (UASB) reactor during 20 cycles operating at different hydraulic retention times (HRTs) of 3, 9, and 12 h using substrate wastewater from the food industry and granular inoculum sludge from a treatment plant as codigestion to explore the relationship between substrates, metabolites, and microorganisms to increase the biohydrogen (BioH2) yield. Operation conditions were constant pH 5.50 ± 0.50, T = 35 °C and a carbon-to-nitrogen (C/N) ratio of 30. It is noteworthy that DF with HRT = 9 h obtained the highest yields of organic matter degradation, and BioH2 in biogas (~60%) was attributed to the adjustment of pH and the codigestion buffer capacity. During DF with HRT = 9, the reactor was 11 times more productive with regards to HRT = 3 h, resulting in its performance with a better yield mean (6.22 mmol H2 g COD−1) and productivity (0.35 LH2 L−1 d) than other HRTs with lower records of 0.42 mmol H2 g COD−1 and 0.05 LH2 L−1 d, respectively. The high abundance of native populations (Lactobacillus and Lactococcus) and intrinsic inoculum (Citrobacter) led to the highest BioH2 production. Most of the production of acetic acid ~590 mg L−1 and butyric acid ~450 mg L−1 confirmed that BioH2 is mainly produced by acetic and butyric metabolic routes, and a direct relation with the percentage of retention of total suspended solids was also found, supporting the biodegradation capacity of the process. [ABSTRACT FROM AUTHOR]

The comprehensive wastewater from a pharmaceutical chemical plant in Shandong Province consists of concentrated wastewater，clean wastewater and domestic wastewater. The concentrated wastewater has the characteristics of high COD and high NH3-N，and therefore requires pretreatment after quality separation to meet the water quality standards for the receiving body of the wastewater treatment plant. Firstly，the concentrated wastewater was pretreated with micro-electrolysis. The pretreated concentrated wastewater was mixed with the clean and domestic wastewaters after removing the suspended solids before undergoing subsequent treatment through an UASB-improved two stage A/O-sequence batch precipitation combination process. Engineering practice showed that this process had a good treatment effect on the comprehensive wastewater，resulting in stable operation and a high capacity to handle impact loads. After treatment，the COD，NH3-N and TN of the effluent were reduced to below 200，3 and 20 mg/L，respectively，meeting the secondary standards in Table 4 of the Comprehensive Sewage Discharge Standard （GB 8978-1996） and meeting the water quality requirements of the receiving water body of the sewage treatment plant.

O aumento da demanda de energia associado às mudanças climáticas tem dificultado o desenvolvimento sustentável. Este artigo buscou avaliar o potencial de recuperação de biogás para geração de energia elétrica, a partir de estações compactas de tratamento de efluentes em edifícios. Foram selecionados três prédios e realizado um estudo de viabilidade econômica. O valor presente líquido (VPL) foi positivo e a taxa interna de retorno (TIR) foi superior à taxa mínima de atratividade em cinco dos seis casos analisados, mostrando que a economia de energia foi suficiente para cobrir os custos de implantação, operação e manutenção, com tempo de retorno de dois a quatro anos para as estruturas de biogás. O reator anaeróbio representou o maior custo, o que indica a importância do desenvolvimento de unidades compactas e de baixo custo para o tratamento descentralizado de águas residuais. Por fim, os resultados evidenciam que o biogás pode ser uma fonte viável de energia em edifícios residenciais.

The UASB-MSBR-coagulation process was applied and industrially researched. The treatment plant had a total capacity of 70 m³/d, after achieving stable operation of 7 d, remarkable removal efficiencies were observed, with COD, SS, NH3-N, TP, and animal and vegetable oil removal rate reaching 97%, 98%, 94%, 96%, and 97%, respectively. The effluent from the treatment system met the first-level discharge standard outlined in the national “Comprehensive Wastewater Discharge Standard” (GB 8978—1996). [ABSTRACT FROM AUTHOR]

A parametric model of the second-layer influent distributor is proposed to increase the reaction efficiency of the up-flow anaerobic sludge blanket. The impacts on the flow efficiency of the main parameters, including the length of distribution pipe, that is, the cylinder radius r1, the eccentricity of the nozzle e, and the number of nozzles n1, are investigated. The optimal parameter combination of the second-layer influent distributoris obtained by single factor analysis and orthogonal analysis. Then the two-layer distributor combination model, including the bottom influent distributor and the second-layer influent distributor, is established and the simulations are conducted to study the effect of the two-layer distributor on flow inside the reactor. The simulation results show that the proposed two-layer distributor can achieve a higher mixture efficiency than the single distributor. [ABSTRACT FROM AUTHOR]

Brewery (BW) and dairy (DW) wastewater are two types of agro-industrial wastewater that are generated in large amounts and, therefore, should be treated effectively and in an environmentally beneficial manner. Both these wastewater types are characterized by a high COD, BOD5, and nutrient content, and conventional wastewater treatment methods such as an activated sludge process may prove to be inefficient due to the possibility of foaming, large biomass production, low activity at low temperatures, and risk of overloading the reactor with a load of organic pollutants. In the context of the described difficulties, anaerobic processes seem to be the best alternative. An interesting research area is the co-digestion of these wastewaters. However, this research direction, so far, has not been frequently reported. Given the gap in the current knowledge, this literature review aims to assess the possibility of BW and DW digestion in anaerobic reactors and provide up-to-date data on the post-treatment methods of effluent generated after the anaerobic digestion process. Despite numerous advantages, anaerobic treatment often requires post-effluent treatment to complete the treatment cycle. [ABSTRACT FROM AUTHOR]

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Abstract Background The upflow anaerobic sludge blanket (UASB) reactors rely on bacterial communities to break down pollutants in wastewater (municipal or industrial). Methods and results In this study, a novel combination of UASB followed by aerobic treatment has been proposed for the treatment of municipal wastewater focusing on bacterial communities using high-throughput sequencing and parasite removal in this novel combination of reactors. Moreover, economic estimation of the compact unit composed of two overlapping UASB reactors, followed by a downflow hanging non-woven fabric (DHNW) reactor, the anaerobic baffled reactor (ABR), and chlorine unit was investigated in this study based on community populations of 1000 and 10,000 inhabitants, with a municipal plant capacity of 54,000 and 540,000 m3/year. Cost estimation was conducted based on two scenarios, one considering the contingency cost and auxiliary facility, and the other excluding them. Non-metric multidimensional scaling (nMDS) revealed that the treatment stages structured the microbial communities. Proteobacteria was the most prevalent phylum in all treatment stages, followed by Bacteroidota in most stages. Firmicutes and Actinobacteria were also present in significant amounts. The treatment system achieved from 40 to 66.67% removal of parasites (parasitic nematode, Cryptosporidium, and microsporidia). Redundancy analysis (RDA) indicated a strong positive correlation between chemical and biological oxygen demand (COD/BOD) with Campylobacterales and could be used as a bioindicator of treatment performance. Conclusion These findings can inform the development of more efficient and sustainable wastewater treatment systems that take into account microbial ecology and economic considerations.

Anaerobic digestion of food waste still faces important challenges despite its world-wide application. An important fraction of food waste is composed of organic material having a low hydrolysis rate and which is often not degraded in digesters. The addition of this less hydrolysable fraction into anaerobic digesters requires a longer hydraulic residence time, and therefore leads to oversizing of the digesters. To overcome this problem, the conversion of the highly biodegradable liquid fraction from fruit and vegetable waste in a up-flow anaerobic sludge blanket (UASB) digester is proposed and demonstrated. The more easily biodegradable fraction of the waste is concentrated in the liquid phase using a 2-stage screw press separation. Then, this liquid fraction is digested in a 3.5 L UASB digester at a high organic loading rate. A good and stable performance was observed up to an organic loading rate (OLR) of 12 g COD/(Lrx.d), with a specific methane production of 2.6 L CH4/(Lrx.d) and a degradation of 85% of the initial total COD. Compared to the conversion of the same initial waste with a continuously stirred tank reactor (CSTR), this new treatment strategy leads to 10% lower COD degradation, but can produce the same amount of methane with a digester that is twice as small. The scale-up of this process could contribute to reduced costs related to the anaerobic digestion of food waste, while reducing management efforts associated with digestate handling and increasing process stability at high organic loading rates. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study on the treatment of industrial chemical wastewater with a high organic load; it is aimed at process cost optimization and possible energy and resources recovery. The facility generates five separate streams of liquid waste, which range in organic strength from practically nil to 400,000 mg/L, with individual flows ranging from 2 to 1400 m3/d. The combined strength and the flow of all the streams are approximately 1500 mg/L COD and 1500 m3/d, respectively; however, excluding the cleaner one (the cooling and condensation water), the maximum average COD concentration rises to 115,000 mg/L, at a flow of 16 m3/d. These wastes are currently trucked away for external processing, at a high cost. The aim of the study was to evaluate the feasibility of the onsite treatment of the facility's waste streams with energy recovery and water reuse. Various approaches were examined, including anaerobic treatment for biogas recovery. The preliminary characterization, however, showed strong inhibition toward anaerobic biomass, and in particular to methanogenesis, induced by some waste components. Further testing led to the conclusion that stream segregation and separate processing could represent the most efficient approach for the management of the facility's liquid discharges and the optimization of resources recovery. A final solution that maximizes treatment efficiency and resources reuse by combining separate aerobic and anaerobic treatment is proposed. [ABSTRACT FROM AUTHOR]

Background: The upflow anaerobic sludge blanket (UASB) reactors rely on bacterial communities to break down pollutants in wastewater (municipal or industrial). Methods and results: In this study, a novel combination of UASB followed by aerobic treatment has been proposed for the treatment of municipal wastewater focusing on bacterial communities using high-throughput sequencing and parasite removal in this novel combination of reactors. Moreover, economic estimation of the compact unit composed of two overlapping UASB reactors, followed by a downflow hanging non-woven fabric (DHNW) reactor, the anaerobic baffled reactor (ABR), and chlorine unit was investigated in this study based on community populations of 1000 and 10,000 inhabitants, with a municipal plant capacity of 54,000 and 540,000 m3/year. Cost estimation was conducted based on two scenarios, one considering the contingency cost and auxiliary facility, and the other excluding them. Non-metric multidimensional scaling (nMDS) revealed that the treatment stages structured the microbial communities. Proteobacteria was the most prevalent phylum in all treatment stages, followed by Bacteroidota in most stages. Firmicutes and Actinobacteria were also present in significant amounts. The treatment system achieved from 40 to 66.67% removal of parasites (parasitic nematode, Cryptosporidium, and microsporidia). Redundancy analysis (RDA) indicated a strong positive correlation between chemical and biological oxygen demand (COD/BOD) with Campylobacterales and could be used as a bioindicator of treatment performance. Conclusion: These findings can inform the development of more efficient and sustainable wastewater treatment systems that take into account microbial ecology and economic considerations. [ABSTRACT FROM AUTHOR]

The leachates emanating from the landfills are high in organic loads and thus become potential sources of contamination for both surface and groundwater. As the landfill ages, the nature of leachate changes from acidic to alkaline. The change in pH level affects the chemical oxygen demand (COD)/biochemical oxygen demand (BOD) ratio and when it is less than 0.63, chemical treatments are more effective over the biological treatment methods such as upflow anaerobic sludge blankets (UASB). The existing literature suggests coagulation–flocculation and advanced oxidation process (Fenton) as effective methods for treating wastewater but no comparison of the two are available. Thus, the present study attempts to identify the most efficient coagulants out of ferric chloride (FeCl3), ferrous sulphate (FeSO4) and alum [Al2(SO4)3]. Ferric chloride leading to 99% colour removal, 98% COD removal, 99% decrease in total organic carbon, 94.3% removal in NH3–N and 91.4% removal in total Kjeldahl nitrogen is observed to be the most efficient coagulant and surprisingly, proves to be even better than Fenton. To understand the field applicability of the two treatment procedures, coagulation with FeCl3 and Fenton are compared with the UASB method which is currently employed at Gazipur landfill site, Delhi. With lesser operational cost than UASB, both FeCl3 and Fenton perform better on cost-efficiency scale. Switching from in-suit UASB method to the FeCl3 method of treatment may result in decreasing the operational cost by 71.9% and to conventional Fenton may result in decreasing the operational cost by 76.8%. [ABSTRACT FROM AUTHOR]

A lab-scale Upflow Anaerobic Sludge Blanket (UASB) reactor was used as a model for evaluating synthetic and complex industrial wastewater treatment, using a solar heater to control temperature. Also, hydrodynamics was assessed using the Computational Fluid Dynamics (CFD) method. Initially, the UASB reactor was operated with synthetic wastewater at Hydraulic Retention Time (HRT) of 24 h in 20 ± 2 °C and 30 ± 2 °C to measure the biogas bubbles production for CFD study. COD removal efficiencies of 85 ± 3% and 95 ± 3%, respectively, with production of 27 and 39 ml CH4/h, correspondingly, were observed. After that, the reactor was fed with complex industrial wastewater. It was evaluated at 24 h in both temperatures. At 30 °C, low COD removal efficiency was observed, being 48 ± 13%, with methane production of 20 ± 3 ml CH4/h. The plug flow pattern was observed in the CFD modelling at HRT of 24 h and 20 °C without considering biogas bubbles interaction. Similar hydrodynamic behaviour was observed at HRT of 24 h and 30 °C. Nonetheless, when biogas bubbles were considered in the CFD modelling, hydrodynamics significantly changed, passing from a plug flow to a complete mix flow pattern. [ABSTRACT FROM AUTHOR]

Tetramethylammonium hydroxide (TMAH) is a known toxic chemical used in the photolithography process of semiconductor photoelectronic processes. Significant amounts of wastewater containing TMAH are discharged from electronic industries. It is therefore attractive to apply anaerobic treatment to industrial wastewater containing TMAH. In this study, a novel TMAH-degrading methanogenic archaeon was isolated from the granular sludge of a psychrophilic upflow anaerobic sludge blanket (UASB) reactor treating synthetic wastewater containing TMAH. Although the isolate (strain NY-STAYD) was phylogenetically related to Methanomethylovorans uponensis, it was the only isolated Methanomethylovorans strain capable of TMAH degradation. Strain NY-STAYD was capable of degrading methylamine compounds, similar to the previously isolated Methanomethylovorans spp. While the strain was able to grow at temperatures ranging from 15 to 37°C, the cell yield was higher at lower temperatures. The distribution of archaeal cells affiliated with the genus Methanomethylovorans in the original granular sludge was investigated by fluorescence in situ hybridization (FISH) using specific oligonucleotide probe targeting 16S rRNA. The results demonstrated that the TMAH-degrading cells associated with the genus Methanomethylovorans were not intermingled with other microorganisms but rather isolated on the granule's surface as a lone dominant archaeon. Key points: • A TMAH-degrading methanogenic Methanomethylovorans strain was isolated • This strain was the only known Methanomethylovorans isolate that can degrade TMAH • The highest cell yield of the isolate was obtained at psychrophilic conditions [ABSTRACT FROM AUTHOR]

The treatment of garlic processing wastewater was investigated in a UASB-SBR system. The experimental results showed that UASB was successfully started up after 64 days of continuous operation with COD removal rate of 45%. SBR start-up phase went through 60 days and the COD removal rate achieved 96%. UASB ran under optimal conditions (HRT of 45 h, pH of 7.5, and temperature of 35 ± 2°C) for 14d and performed well in organic matter treatment. SBR played a major part in nitrogen and phosphorus removal when running under optimal conditions (cycle time of 12 h, temperature of 25°C, organic loading of 0.72 kgCOD/(m3·d), and COD of 6000 mg/L) for 18d. Secondly, the microbial community structure indicated that the abundance of β-Proteobacteria and α-Proteobacteria in the sludge reached 30.05% and 47.57%, respectively, and played a crucial part for the organic matter, nitrogen and phosphorus removal in the SBR. After UASB-SBR system had been stabilised with influent COD of 9800 mg/L, the average COD, TP, NH3-N and TN removal rates were 99%, 94.82%, 87.07% and 94.87%, respectively, which were 3%, −2%, 1% and 3.5% higher than SBR running alone under optimal conditions. UASB coupled with SBR process had an excellent performance for high-concentration garlic processing wastewater. [ABSTRACT FROM AUTHOR]

A region's population growth inevitably results in higher water consumption. This persistent rise in water use increases the region's wastewater production. Consequently, due to this increase in wastewater (influent), Wastewater Treatment Plants (WWTPs) are required to run effectively in order to handle the huge demand for treated/processed water (effluent). Knowing in advance the influent and effluent parameters increases the operational efficiency and enables cost-effective utilization of diverse resources at wastewater treatment plants. This paper is based on a prediction/forecasting of an influent quality parameter, namely total MLD, as well as effluent quality parameters, namely MPN, BOD, DO, COD and pH for the real-time data collected pre-, during and post-COVID-19 at the Bharwara WWTP in Lucknow, India. It is the largest UASB-based wastewater treatment facility in Uttar Pradesh and the second largest in Asia. In this paper, we propose a novel model namely, wPred comprising extensions of SARIMA with seasonal order and ANN-based ML models to estimate the influent and effluent quality parameters, respectively, and compare it with the existing machine learning models. The lowest sMAPE error for the influent parameters using wPred is 2.59%. The findings of the paper show a strong correlation (R-value), up to 0.99, between the effluent parameters actually measured and predicted. As a result, the model designed in this paper has an acceptable level of accuracy and generalizability which efficiently predicts/forecasts the performance of Bharwara WWTP. [ABSTRACT FROM AUTHOR]

This study investigates the effectiveness of modified micrometer graphite (MMG) in enhancing the biodegradation of perchlorate in sludge. Different MMG types, specifically GO205, GO003, ATGO205, and ATGO003, were evaluated for their impact on perchlorate degradation rates. The results showed a significant acceleration in perchlorate reduction, particularly with the MMG variant GO205, which achieved complete degradation within 48 hours, marking a six-fold increase compared to controls. This rapid degradation also correlated with enhanced microbial activity, as indicated by increased cytochrome C concentrations and electron transport system activity, suggesting a boost in overall microbial metabolic functions. Additionally, shifts in the microbial community composition were observed, with a notable increase in perchlorate-reducing bacteria populations. The study highlights MMG's potential to improve perchlorate remediation processes efficiently and offers promising insights into its application in treating perchlorate-contaminated environments. [Display omitted] • Addressed persistent perchlorate contamination from industrial sources. • Used MMG to enhance microbial perchlorate biodegradation in batch experiments. • Conducted UASB reactor trials with MMG with 40 days. • MMG can change microbial community structure and pcrA gene transcription. • MMG enhances biodegradation efficiency, aiding sustainable wastewater treatment. [ABSTRACT FROM AUTHOR]

Triclosan (TCS) and tetracycline (TC) as common antibacterial agents are frequently detected in the influent of wastewater treatment plants. The TCS and TC exposure patterns may determine their impacts on wastewater treatment microbiomes, on which information remains unknown. In this study, the impacts of sequential exposure of TCS and TC on methanogenic digestion microbiomes in upflow anaerobic sludge blanket (UASB) reactors were analyzed and compared with that of the same microbiomes being simultaneously exposed to TCS and TC. Results indicated that the UASB reactor 2 (MD2) with sequential TCS-TC exposure consistently demonstrated higher chemical oxygen demand (COD) removal efficiency (94.7 %). In contrast, in the MD1 reactor, COD removal efficiency decreased from 94.4 % to 82.7 % upon simultaneous exposure to TCS and TC. Accordingly, a 1.8 times higher enrichment of total antibiotic resistance genes (ARGs) was observed in MD1 relative to MD2. Using a dissimilarity-overlap approach, the MD2 microbiome with sequential exposure was predominantly mediated by deterministic factors in their community assembly (largely contributed by abundant and intermediate biospheres), resulting in microbial interaction networks with higher average clustering coefficients and shorter average path lengths, compared to the MD1 microbiomes. Our results could support sustainable management of TCS and TC contamination in wastewater treatment plants. [Display omitted] • The MD2 reactor exhibited more stable COD removal. • The MD2 reactor showed less enrichment of antibiotic resistance genes. • Deterministic factors primarily governed the MD2 microbial community assembly. • MD2 microbiomes had higher clustering coefficients and shorter path lengths. [ABSTRACT FROM AUTHOR]

A recirculação de efluente nitrificado para reatores desnitrificantes em sistemas anaeróbios-aeróbios pode implicar na melhora do tratamento de esgotos. Nesse sentido, este estudo avaliou experimentalmente o efeito da razão DQO/N-NO3- na desnitrificação em reator UASB e, a partir dos resultados e com cálculos teóricos de balanço de massa, foi estimado o efeito de diferentes razões de recirculação (R) na concentração final de nitrogênio total em um sistema teórico. Para razões DQO/N-NO3- entre 1,6 - 5,7, a eficiência de desnitrificação varia linearmente entre 31,7 ± 4,3% e 98,6 ± 0,1%, com remoção completa para razões superiores a 5,7. Com a simulação teórica, estimaram-se concentrações finais de nitrogênio total próximas a 30, 20, 15 e 10 mgL-1 utilizando razões de recirculação iguais a 1,5; 2,5; 4,0 e 6,0. Embora não avaliado, o aumento de R deve levar em consideração consequências como a possibilidade de arraste de sólidos, a redução da produção de biogás e a entrada de OD no reator anaeróbio.

Methane is a powerful greenhouse gas and a source of energy. Recovering this gas means lower greenhouse gas emission and potential reduction of energetic costs. The lack of full-scale results, the use of different methodologies to detect dissolved methane (d-CH4) and the fact that no process to remove d-CH4 from anaerobic effluents is energetically or economically viable at full-scale urged a different approach to the problem. To avoid methodological interference and facilitate comparison of results the Standard Test Method number D8028-17 published by ASTM International can be used to determine d-CH4. The use of real anaerobic reactor effluent also helps results to be compared. In this study, 80 samples from a full-scale anaerobic reactor showed an average concentration of dissolved methane of 14.9 mg·L−1, meaning an emission of 229 kg of CO2 eq·h−1 and an average of 113.5 kW wasted. Using spray nozzles, an alternative to the methods being researched, the average methane recovery was 11.5 mg·L−1 of CH4, an efficiency of 81.6%, meaning 177 kg of CO2 eq·h−1 emissions avoided and 87.9 kW of recoverable energy. HIGHLIGHTS Use of standard method to detect dissolved methane.; Use of real Upflow Anaerobic Sludge Blanket (UASB) reactor effluent.; Simple alternative method to recover dissolved methane.; High efficiency.;

Although in a critical position in the economy, the paper industry releases a lot of wastewater that requires adequate treatment for sustainable development. This study presents an application of Life cycle assessment (LCA) with the ReCiPe tool on the wastewater treatment plant (WWTP) of a paper factory in Vietnam to evaluate the environmental effect of the individual techniques in WWTP, especially the internal circulation (IC) reactor, a pioneer and practical anaerobic technology. Both Midpoint and Endpoint categories results demonstrated that chemical use and electricity consumption mainly contributed to the environmental impact in the WWTP. The Dissolved air flotation (DAF) and Moving bed biofilm reactor (MBBR) are classified as effective techniques to reduce the impacts on the environment. Moreover, the comparison of LCA between IC and up-flow anaerobic sludge bed (UASB) shows that IC is the better practically green technique for the environment. HIGHLIGHTS Life cycle assessment was applied in a paper mill wastewater treatment plant.; Midpoint and Endpoint indicators were employed to evaluate environmental impact.; Two scenarios of electricity generating from biogas between Internal circulation and up-flow anaerobic sludge bed were investigated.; Chemicals use and energy consumption were determined to be the most factors to damage indicators.;

UASB (upflow anaerobic sludge blanket) reactors have been recognized as a viable option for sewage treatment. However, in order to improve the UASB effluent quality, some type of post-treatment must be implemented. The aims of this study were (i) to establish a start-up methodology of a full-scale anaerobic–aerobic system treating sewage, (ii) to evaluate the concentrations of different constituents in the influent and effluent of the anaerobic and aerobic reactors as well as the removal efficiencies in every step of the system, and (iii) to define relevant operative aspects of the anaerobic and aerobic reactors. The Tunja (Colombia) wastewater treatment plant consists of three modules with preliminary treatment followed by UASB reactors with post-treatment of activated sludge. The results of this investigation showed that the effluent system meets the Colombian environmental legislation with average removal efficiency values of BOD (88 +/− 5%), COD (87 +/− 4%), and TSS (94 +/− 5%). The UASB reactor start-up was conducted without an inoculum, requiring a period of 120 days. The evaluation of the combined systems was conducted over 300 days. Moreover, a methodology to operate the system during and after the start-up of the anaerobic reactor was defined. It was demonstrated that the anaerobic effluent can deteriorate the sludge in the aerobic tank. In order to avoid this, important operational aspects must be considered during the operation of the system, such as the implementation of a raw wastewater bypass higher than 15% and monitoring of the anaerobic effluent settleable solid concentration (<0.3 mL/L). [ABSTRACT FROM AUTHOR]

Anaerobic ammonia oxidation (ANAMMOX) technology is a novel biological nitrogen removal technology with potential applications for the treatment of nitrogenous wastewater treatment prospects. Most of the literature explores the growth environment of anaerobic ammonia-oxidizing bacteria and total nitrogen removal efficiency but the influence of reactor operating conditions (such as up-flow rate) on the treatment efficiency and sludge growth property of anaerobic ammonia-oxidizing bacteria is rarely discussed. Therefore, the purpose of this study is to discuss the effect of up-flow rate on the treatment efficiency and sludge property of the anaerobic ammonia oxidation treatment procedure adopting up-flow anaerobic sludge bed (UASB) as a reactor. The results show that up-flow rate has a significant effect on sludge concentration and sludge growth rate. The highest sludge concentration and maximum sludge growth rate could be obtained at the up-flow rate of 3.21 m/h. According to the analysis results of the sludge concentration, we speculate that when the flow rate was lower than 3.21 m/h, the sludge particles did not easily collide with each other to produce a larger sludge floc. On the contrary, when the up-flow rate was higher than 3.21 m/h, the larger sludge floc could be decomposed by the shear force. The sludge concentration was reduced by these two reasons. On the other hand, the average total nitrogen volume removal rates in test runs 1 through to 4 were 0.18 g-N/m3/d, 0.19 g-N/m3/d, 0.20 g-N/m3/d and 0.20 g-N/m3/d at up-flow rates from 1.95 m/h to 3.70 m/h, respectively. Therefore, the treatment efficiency was not affected by the up-flow rate in these operating conditions. [ABSTRACT FROM AUTHOR]

The application and design of treatment systems in wastewater are necessary due to antibiotics' potential toxicity and resistant genes on residual effluent. This work evaluated a coupled bio-electrochemical system to reduce chloramphenicol (CAP) and chemical oxygen demand (COD) on swine wastewater (SWW). SWW characterization found CAP of 99.99%, respectively. This coupled system can be applied to eliminate antibiotics and other organic pollutants in agricultural, industrial, municipal, and other wastewaters. HIGHLIGHTS Preliminary application of an anaerobic Reactor (UASB) allowed a reduction of 62.4% initial concentration of chloramphenicol.; The optimization of the electrooxidation process, for chloramphenicol (CAP) removal, reduces operation time and current intensity.; UASB + EO combined treatment allowed 82.35 and >99.9% of COD and CAP elimination.; The coupled system proved to be helpful for the CAP treatment in swine wastewater;

O presente trabalho teve como objetivo realizar uma análise de desempenho e confiabilidade de reatores UASB em 18 estações de tratamento de esgotos sanitários descentralizadas em escala plena. A confiabilidade foi avaliada por meio da metodologia desenvolvida por Niku et al. (1979) para os parâmetros DQO e SST. A verificação da forma da distribuição de frequência desses parâmetros consistiu de testes de aderência às distribuições Normal, Lognormal, Gama e Exponencial, por meio dos testes Qui-quadrado e Kolmogorov-Smirnov. Verificou-se que os dados de DQO e SST efluentes aos reatores UASB seguiu uma distribuição lognormal. De uma forma geral, o desempenho dos reatores no atendimento aos padrões de descarte para os parâmetros DQO e SST não foi satisfatório. Em uma análise conjunta dos coeficientes de confiabilidade, concentrações de projeto e percentuais esperados de atendimento constatou-se a pouca confiabilidade da maioria dos reatores em relação aos constituintes DQO e SST, sendo indicativo de sobrecargas orgânicas e hidráulicas, respectivamente.

The treatment of sugarcane vinasse is still a challenge to develop a sustainable bioethanol production. Anaerobic digestion (AD) is the most promising treatment of vinasse since energy in the form of biogas can be recovered. The aim of this work was to understand the dynamics of the microbial community in a 100-m3 upflow anaerobic sludge blanket (UASB) methanogenic reactor at start-up and during two periods of bioethanol production. An inter-harvest period in which the reactor was not fed was also studied. Metabarcoding analysis of the V4 region of the 16S rRNA gene showed that Firmicutes, Synergistetes, Chloroflexi, and Proteobacteria were the dominant phyla. Firmicutes was abundant, suggesting that this group plays a specific role in the treatment of vinasse. The inoculum adaptation to vinasse was correlated with the microbiota diversity and dynamics. The microbiota diversity was higher during the first harvest and reflected the initial microbial composition. During the second harvest, the increasing organic loading rate (OLR) and the adaptation to the new effluent selected a less diverse community which produced the biogas in the reactor. The qPCR of the mcrA gene and methanogenic activity tests showed that the abundance of methanogens increased over time and remained stable even after the stop period. This work shows the plasticity of the microbial community, which adapted its structure to the changes in the feed and persisted during starvation periods in the reactor. A time-series of microbiological information is necessary to a comprehensive understanding of full-scale reactor maintenance. [ABSTRACT FROM AUTHOR]

In the present study, the treatment of slaughterhouse wastewater was carried out in a sequential batch reactor. A lab-scale column type reactor was fabricated with Perspex material having dimensions of 10 cm diameter, 100 cm height, and an effective volume of 7 liters provided with ports at different levels. The reactor performance was evaluated in terms of COD, BOD, TSS, TKN, and phosphorus removal. The reactor was operated for 432 days; the effectiveness of the reactor is the temperature of wastewater in the reactor. The removal efficiencies of COD and BOD were84% and 80% in the reactor. The maximum TSS removal was around 87% and TKN's maximum removal efficiency was 61% in aerobic treatment. Phosphorus maximum removal efficiency was around 68%, in the meantime pH and alkalinity were also monitored, and no change in the pH was reported throughout the experiment. On the other hand, an aerobic SBR is also operated using wastewater after the DAF unit. In the same manner, the reactor was operated with initially diluted wastewater (05 times) and kept HRT 8 h. The reactor performance was studied in terms of COD, BOD, TSS, TKN, and phosphorus. The maximum removal efficiencies of COD and BOD were 80% and 81% respectively. The maximum removal efficiencies of TSS, TKN, and Phosphorus were 73%, 81%, and 69% respectively. It is concluded that the removal efficiency of COD was better in the anaerobic process as compared with the aerobic process in addition the generation of methane gas during the degradation of organic matter can be used for operating the aerobic unit by making some necessary arrangements. Besides this, it is also concluded that the removal efficiency of TKN was better in the aerobic process as compared with the anaerobic process. There was a buildup of VSS from 4500 mg.L-1 to 6500 mg.L-1 in the study. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 2 O 3 Nanomodified Pumice was synthesized by hydrothermal method. • Coupling Ozonation and modified pumice enhanced UASB was firstly applied to the treatment of landfill leachates. • Ozonation and Fe 2 O 3 Nanomodified Pumice make the start-up time of the reactor accelerated. • UASB process achieved efficient COD (93%) removal and methane productivity (58.23 d/L) Pumice, a material with good application prospects in adsorption and water treatment, has less research on its improvement. In this study, the positive benefits of anaerobic reaction were explored by loading iron oxide on pumice and combined with ozone advanced oxidation. In the experiment, the Upflow Anaerobic Sludge Blanket (UASB) reactor was enhanced with pretreatment from an ozone generator (6 L/min flow rate, delivering 500 ± 5 % mg/L of ozone) and the addition of 250 ml of Fe 2 O 3 Nanomodified Pumice (FP). The results showed that FP could play an active role in the formation of sludge particles. The addition of FP increased the level of interspecies electron transfer (DIET), improved the reaction of hydrolysis and acid production, methane production and the activity of dominant species. At the same time, the advanced oxidation of ozone and the improvement of FP on the decomposition ability avoid the accumulation of macromolecular volatile fatty acids and reduce the risk of reactor acidification. At the microbial level, the addition of FP better promoted the correlation between the three dominant strains of Firmicutes, Synergistota, and Desulfobacteriota, and promoted the connection between the reactions. Under these promoting effects, not only the start-up time of the reactor was accelerated, but also the anti-load capacity was improved, and the reactor could maintain a removal rate of more than 90 % at an organic load of 53.89 kgCOD / (m3 · d). [ABSTRACT FROM AUTHOR]

Considering the removal of pollutants and the resource recovery in wastewater, it is crucial to address the conflict between phosphorus pollution and phosphorus resources during wastewater treatment. This study investigated the transformation law of phosphorus in an up-flow anaerobic sludge bed reactor using different phosphorus source substrates. In addition, metagenomics sequencing was used to analyze microbial community succession and changes in the key functional genes in the reactor. Results showed that when sodium hypophosphite and sodium phosphite were used as the phosphorus sources, the average removal efficiency of total phosphorus was 6.43 % and 5.69 %, respectively. The resulting average phosphine concentrations were 109.76 mg/m3 and 72.77 mg/m3, respectively. Sodium hypophosphite was the more effective phosphorus source for Proteobacteria growth. The ppa , ppk , ppx and gcd genes were all up-regulated when exposed to the two phosphorus sources. On day 90 of the experiment, the relative abundances of these four genes in the reactor with sodium hypophosphite as phosphorus source were 0.0046 %, 0.0025 %, 0.0036 %, and 0.0014 %, respectively. In contrast, in the reactor with sodium phosphite as a phosphorus source, the relative abundances of the ppa , ppk , ppx and gcd genes were 0.0009 %, 0.0005 %, 0.0014 %, and 0.0001 %, respectively. Sodium hypophosphite was more effective than sodium phosphite in promoting the dissolution of inorganic phosphorus in microbial cells. [Display omitted] • Sodium hypophosphite was more easily reduced into phosphine. • Conversion of IP to OP in sludge can be promoted by using sodium hypophosphite. • Sodium hypophosphite was more conducive to the growth of Proteobacteria. • ppa , ppk , ppx and gcd genes were all up-regulated under the two phosphorus sources. [ABSTRACT FROM AUTHOR]

[Display omitted] • Starch and magnetite have been stuffed into a PVA gel to form PVA/Fe/Starch beads. • The PVA/Fe/Starch bead has been fabricated to enhance anaerobic dye decolorization. • The material was stable in continuous treatment within a UASB for 302 days. • The material helped to improve the decolorization ability in the UASB reactor. • The material contributes to strengthening the resilience of the UASB reactor. A novel bio-carrier, PVA/Fe/starch gel bead, was fabricated and developed to enhance the anaerobic treatment performance of synthetic azo dye-containing wastewater. PVA-gel beads with 5 % magnetite and 0.5 % starch were optimal for physical strength and treatment performance. A pair of 2 L-up-flow anaerobic sludge blankets (UASB), one with the bead (UB) and another without (U) as a controller, operated continuously at 30 °C and an HRT of 11–24 h for 302 days. UB showed better performance than U in most phases, especially with influent dye of 200 mg·L−1, suggesting a greater tolerance to dye toxicity of UB than U. Microbial analysis revealed that the PVA/Fe/starch gel beads successfully captured the dye degrader Clostridium. Diversity indices indicated that PVA/Fe/Starch gel beads effectively support microbial diversity and resilience under varying dye concentrations. Overall, these findings demonstrate the potential of PVA/Fe/Starch gel beads to improve the stability and efficiency of the dye treatment system. [ABSTRACT FROM AUTHOR]

In this study, polyvinyl alcohol (PVA), granular active carbon (AC), and Ca2+/polyacrylamide (PAM) were used to enhance granulation in three upflow anaerobic sludge blanket (UASB) reactors, UASB-PVA, UASB-AC, and UASB-PAM. The experimental results showed that the start-up of the UASB-PVA reactor was the fastest, UASB-PVA, UASB-AC, and UASB-PAM took 44, 48 and 54 d, respectively, and the performance of UASB-PVA was relatively stable and less fluctuating. When organic load was up to ∼13 kg chemical oxygen demand (COD)/(m3·d), biogas production of PVA sludge, AC sludge, and PAM sludge were 19.10, 12.32, and 15.13 L/d, respectively, and the biogas production of the three reactors was: UASB-PVA>UASB-PAM>UASB-AC. After 128 days of operation, the granulation effect of the sludge from the three reactors was ranked from high to low in the following order: UASB-PVA>UASB-AC>UASB-PAM. In the process of load shock, the COD removal efficiency (CODRE) and N H 4 + -N removal efficiency ( N H 4 + -NRE) of the UASB-PVA was the most stable under different load impacts, the standard deviation of CODRE and N H 4 + -NRE were 2.7% and 8.7%, respectively. The total fluorescence intensity of dissolved organic matter in the effluent of UASB-PVA, AC, and PAM were 2.5 × 105 – 5.5 × 105, 1.8 × 105 – 13.2 × 105, and 1.5 × 105 – 11.5 × 105, respectively. The change range of the total fluorescence intensity of UASB-PVA was the minimal under load impact. The UASB-PVA can play an important role in the upgrading of sewage treatment plants. [ABSTRACT FROM AUTHOR]

The bioelectrochemical enhancement of direct interspecies electron transfer (DIET) for methane production was investigated in a UASB reactor under different electrode surface areas. The specific methane production rate is stabilized at 316.7 mL/g COD in the bioelectrochemical UASB (BUASB) reactor with an electrode surface area of 10 m2/m3, which is significantly higher than the 216.8 mL/g COD of the UASB reactor. The electroactive bacteria, involved in the DIET for methane production, is signifianctly increased in the BUASB reactor. When the electrode surface area is expanded to (20 and 30) m2/m3, the specific methane production rates in the BUASB reactor are further increased to (358.4 and 361.0) mL/g COD, respectively (p-value > 0.05). The theoretical methane production from the electrode surface is approximate 3.1% of the total methane production in all BUASB reactors, and the bioelectrochemical methane production is mainly attributed to the biological DIET pathway (54%) in the bulk solution. The BUASB reactor at the electrode surface area of 20 m2/m3 showes better performance according to the methane production, process stability, and enrichment of electroactive microorganisms. The bioelectrochemical system provides a new platform that can dramatically improve the performance of UASB process for treating brewery wastewater. [Display omitted] • Bioelectrochemical system enriches electroactive microorganisms in the bulk solution. • Electroactive microorganisms facilitate the DIET pathways for methane production. • BDIET is dominant electron transfer pathway for bioelectrochemical methane production. • Ratio of Bacteroidetes/Firmicutes shows an exponential relation to methane production. • The optimal surface area of polarized electrode for the BUASB process is 20 m2/m3. [ABSTRACT FROM AUTHOR]

The discharge of raw wastewater into the environment can be a contamination source of Giardia spp. cysts and Cryptosporidium spp. oocysts. The UASB (Upflow Anaerobic Sludge Blanket) reactor is the most popular technology applied for wastewater treatment in Brazil, nevertheless there is little information concerning its capacity for (oo)cyst removal. In this context, this study investigated the occurrence and removal of Giardia spp. cysts and Cryptosporidium spp. oocysts by three different UASB reactors (i.e. Reactor A, B, and C) treating different wastewater types. In the wastewater influent, the concentration varied from 493.3 to 14,000 cysts·L-1 for Giardia spp. and from 'not detected' to 53.3 oocysts·L-1 for Cryptosporidium spp.. The (oo)cyst concentration increased after the anaerobic treatment in Reactors A and B, while Giardia spp. log-removal of 0.5 ± 0.2 was found in Reactor C. The increment in (oo)cyst concentration may happened due to the inefficacy for (oo)cyst removal by the specific UASB reactor and/or due to the reduction of matrix interference for reactor effluent samples in the detection method. The results suggest that hydraulic retention time (HRT) may be the key parameter for Giardia spp. removal by the UASB reactor. Furthermore, no parameter analysed (physical-chemical and indicator microorganisms) showed a common correlation with the (oo)cyst concentration in the three UASB reactors. Considering that official data of cryptosporidiosis and giardiasis cases are rarely reported in Brazil, monitoring Giardia spp. cysts and Cryptosporidium spp. oocysts in wastewater could be an alternative to estimate the occurrence of diseases in the served population. [ABSTRACT FROM AUTHOR]