Extremely effective self-sufficient sugar factory wastewater treatment plant and its methanogenic microbial consortium

The work studied the methanogenic microbial consortium in a coal mine from the Bogotá basin in Colombia. Ex situ coal-enrichment cultures were established for in vitro growth and de novo gas production. Biogenic gas produced by cultures was analyzed by gas chromatography using thermal conductivity and flame ionization detectors. Cultures were used to isolate microbial specimens and to generate 16S rRNA gene libraries employing bacterial and archaeal primer sets. The gas chromatographic analysis showed methane production at 37 oC, but not at 60 oC, where CO2 was the major component of the biogenic gas. 16S rRNA gene sequence analysis of microbial isolates and clone libraries established that the methanogenic microbial consortium was formed by bacteria species from Bacillus and Gracilibacter genera plus archaea from the Methanothermobacter genus. This methanogenic microbial consortium was potentially responsible for biogenic gas generation in La Ciscuda coal mine. The results suggested that these methanogens produced methane by hydrogenotrophic or CO2 reduction pathways.

The anaerobic packed-bed (AP) and hybrid packed-bed (HP) reactors containing methanogenic microbial consortia were applied to treat synthetic soft drink wastewater, which contains polyethylene glycol (PEG) and fructose as the primary constituents. The AP and HP reactors achieved high COD removal efficiency (>95%) after 80 and 33 days of the operation, respectively, and operated stably over 2 years. 16S rRNA gene pyrotag analyses on a total of 25 biofilm samples generated 98,057 reads, which were clustered into 2,882 operational taxonomic units (OTUs). Both AP and HP communities were predominated by Bacteroidetes, Chloroflexi, Firmicutes, and candidate phylum KSB3 that may degrade organic compound in wastewater treatment processes. Other OTUs related to uncharacterized Geobacter and Spirochaetes clades and candidate phylum GN04 were also detected at high abundance; however, their relationship to wastewater treatment has remained unclear. In particular, KSB3, GN04, Bacteroidetes, and Chloroflexi are consistently associated with the organic loading rate (OLR) increase to 1.5 g COD/L-d. Interestingly, KSB3 and GN04 dramatically decrease in both reactors after further OLR increase to 2.0 g COD/L-d. These results indicate that OLR strongly influences microbial community composition. This suggests that specific uncultivated taxa may take central roles in COD removal from soft drink wastewater depending on OLR.

Biphenyl was readily degraded and mineralized to CO2 and CH4 by a PCB-dechlorinating anaerobic microbial consortium. Degradation occurred when biphenyl was supplied as a sole source of carbon or as a co-metabolic substrate together with glucose and methanol. p-Cresol was detected and confirmed by mass spectroscopy as a transient intermediate. Production of 14 C-CO2 and 14C-CH4 from 14C-biphenyl was observed in the approximate ratio of 1:2. The results indicated the existence of novel pathways for biphenyl degradation in a natural anaerobic microbial community.

Anaerobic dechlorination of trichloroethylene (TCE) to ethylene using complex organic materials

Isolation and characterization of a novel cinosulfuron degrading Kurthia sp. from a methanogenic microbial consortium

This research focuses on the microbial recovery of elemental tellurium (Te(0)) from aqueous streams containing soluble tellurium oxyanions, tellurate (Te(VI)), and tellurite (Te(IV)). An anaerobic mixed microbial culture occurring in methanogenic granular sludge was able to biocatalyze the reduction of both Te oxyanions to produce Te(0) nanoparticles (NPs) in sulfur-free medium. Te(IV) reduction was seven times faster than that of Te(VI), such that Te(IV) did not accumulate to a great extent during Te(VI) reduction. Endogenous substrates in the granular sludge provided the electron equivalents required to reduce Te oxyanions; however, the reduction rates were modestly increased with an exogenous electron donor such as H2. The effect of four redox mediators (anthraquinone-2,6-disulfonate, hydroxocobalamin, riboflavin, and lawsone) was also tested. Riboflavin increased the rate of Te(IV) reduction eleven-fold and also enhanced the fraction Te recovered as extracellular Te(0) NPs from 21% to 64%. Lawsone increased the rate of Te(VI) reduction five-fold, and the fraction of Te recovered as extracellular material increased from 49% to 83%. The redox mediators and electron donors also impacted the morphologies and localization of Te(0) NPs, suggesting that NP production can be tailored for a particular application.

Complete degradation of high concentrations of tetrachloroethylene by a methanogenic consortium in a fixed-bed reactor

An alternative electron-donor and highly thermo-assisted strategy for solar-driven water splitting redox chemistry towards efficient hydrogen production plus effective wastewater treatment

Nitrate-reducing and methanogenic microbial consortia capable of using 2-furaldehyde (furfural) as a sole source of carbon and energy were isolated from a mixture of soil and municipal sewage and from municipal anaerobic digestor sludge, respectively. Under nitrate-reducing conditions, more than 97% of the furfural was biodegraded in 0.25, 1.5, 4 and 32 d at initial substrate concentrations of 0.5, 5, 50 and 500 ppm, respectively. In all cases microbial populations were able to reduce furfural levels to less than the detection limit of 20 ppb as measured by HPLC. At 500 ppm, there was a 12-d lag period before detectable activity was noted, while there was no lag period at the lower concentrations tested. When the disappearance of both furfural (50 ppm) and nitrate was measured, the molar ratio of nitrate to furfural consumed was approximately 4.2:1, Which is in good agreement with the theoretical ratio of 4.0:1. The biodegradation of furfural was generally more rapid under methanogenic than under nitrate-reducing conditions. The methanogenic consortium was able to metabolize 97% of the furfural in 2, 4, 48 and 144 h at initial concentrations of 0.5, 5, 50 and 500 ppm, respectively. No lag period was noted at any concentrations tested. As under nitrate-reducing conditions, populations were able to reduce furfural levels to less than 20 ppb. Complete metabolism of furfural in cultures that received an initial concentration of 50 ppm resulted in the production of 0.056 mM methane or 43% of the theoretical yield that would result from complete conversion of the material to carbon dioxide and methane. This is the first report of the biodegradation of furfural under nitrate-reducing conditions.

Regional discrepancy of microbial community structure in activated sludge system from Chinese WWTPs based on high-throughput 16S rDNA sequencing

Having recently published an article in AWWA Water Science, Amina Stoddart answered questions from the publication's editor-in-chief, Kenneth L. Mercer, about the research. An Automated and High-Throughput Method for Adenosine Triphosphate Quantification Fatou Secka, Nicole E. Allward, and Graham Gagnon I am an assistant professor in the Centre for Water Resources Studies in the Department of Civil and Resource Engineering at Dalhousie University in Nova Scotia, Canada. Our team has broad research interests in the water and wastewater treatment space. Our team members can often be found in our local wastewater treatment plants working on process optimization or testing new treatment and monitoring strategies. Amina hikes near Morden, Nova Scotia. I was introduced to water research as an undergraduate student at Acadia University. I was offered an undergraduate student research assistant position by my favorite professor and now my friend and colleague, Dr. Jennie Rand. I was responsible for collecting drinking water samples from a local water system and doing chemical and microbiological water quality analyses. I loved visiting the treatment plant and pumping station and learning how the system worked. My favorite days continue to be those that I spend onsite in water and wastewater treatment plants. Amina, a kayaking enthusiast, navigates the Bay of Fundy. Students (left to right) Sydney Lowe, Gillian Stanton, and Madison Gouthro take a break from operating a wastewater pilot plant at the Dartmouth Wastewater Treatment Plant in Halifax. Photo by Gillian M.L. Stanton Amina and her dog Mel enjoy an afternoon at her converted shipping container cabin. Water samples should be analyzed for microbiological parameters without delay to ensure that they remain representative of the water quality at the time the sample was taken. This work was led by our students, Fatou Secka and Nicole Allward, and their goal was to automate ATP analysis so that many samples could be analyzed in a high-throughput manner, reducing overall operator involvement and analysis time. I am an avid kayaker and love to explore lakes and coastlines by kayak. Effective wastewater treatment is a key component to ensuring that these spaces remain unpolluted and available to be enjoyed now and into the future. Anytime we can assess the microbiological quality of drinking water quickly and easily, we are taking a step to protect public health. Health Canada recently revised its document, Guidance on the Use of Heterotrophic Plant Counts in Canadian Drinking Water Supplies, to recognize other metrics that can be used to assess biological stability in drinking water distribution systems (now Health Canada's Guidance on Monitoring the Biological Stability of Drinking Water in Distribution Systems). ATP was included in this document as a suggested parameter/method to assess the biological stability. It is anticipated that our method could be of use to utilities that may generate a significant number of ATP samples. I grew up in Nova Scotia. I lived in its capital city, Halifax, for many years while I was attending Dalhousie University and continue to travel there every day for work. Halifax is surrounded by the beautiful Halifax Harbour. Unfortunately, when I was growing up, the harbour was well known locally for its poor water quality as a result of many years of direct discharge of raw sewage. Treatment systems have since been put in place and the harbour water quality has improved significantly. However, there is still work to be done. My first major grant as an assistant professor involves a partnership with Halifax Water in which we are investigating treatment optimization strategies to improve effluent water quality at the wastewater treatment plants that discharge into the harbour. I live in rural Nova Scotia with my partner Jordan, our daughter Willa, our dog Mel, and our horses Jac, Rob, and Brie. We love spending our free time horseback riding, kayaking, hiking, and working in our vegetable gardens. On weekends we like to spend time relaxing near the ocean in our converted shipping container cabin.

My Life in Science

Background: The Tahu Sehat Sari industrial area in Cokro Village is one of the largest tofu manufacturers, processing 3 tons of soybeans daily with 88 employees. However, wastewater quality tests reveal that the effluent exceeds regulatory limits set by Central Java Regional Regulation No. 5 of 2012, with BOD at 422.5 mg/L, COD at 845 mg/L, and TSS at 1940 mg/L. Effective wastewater treatment is necessary to ensure compliance with environmental standards and minimize pollution. Methods: This study evaluates wastewater treatment alternatives, including Anaerobic Digester, Anaerobic Biofilter, and Aerobic Biofilter, with the addition of Effective Microorganisms 4 (EM4) to enhance organic waste degradation. Wastewater samples were tested for COD, BOD, and TSS levels before and after treatment to assess removal efficiency. Findings: The implementation of EM4 significantly improved wastewater quality, achieving an 86% reduction in COD with a 0.3% EM4 concentration in aerobic treatment. EM4’s fermentation bacteria effectively minimized organic contaminants. The selected treatment methods—Anaerobic Digester, Anaerobic Biofilter, and Aerobic Biofilter—proved suitable for treating tofu wastewater, with final effluent concentrations of COD at 2.4 mg/L, BOD at 0.3 mg/L, and TSS at 35 mg/L, meeting regulatory standards. The estimated cost for the construction of a Wastewater Treatment Plant (WWTP) is IDR 1,177,378,400, with monthly operation and maintenance expenses of IDR 6,110,297. Conclusion: The study confirms that an integrated wastewater treatment system using anaerobic and aerobic biofilters combined with EM4 is effective in reducing organic waste contamination in tofu industry effluent. Further assessment of land use and distribution systems is recommended to optimize wastewater management. Novelty/Originality of this article: This research contributes to sustainable wastewater treatment in tofu production by integrating EM4 technology with anaerobic and aerobic filtration, achieving high pollutant removal efficiency. The study also provides a financial analysis of WWTP implementation, highlighting its feasibility for similar small and medium enterprises.

Effective wastewater treatment is of critical importance for preserving public health and protecting natural environments. Key processes in wastewater treatment, such as denitrification, are performed by a diverse community of prokaryotic and eukaryotic microbes. However, the diversity of the microbiome and the potential role of the different microbial taxa in some wastewater treatment plant setups is not fully understood. We aimed to investigate the presence and diversity of denitrifying bacteria of the candidate family Azoamicaceae that form obligate symbioses with protists in wastewater treatment plants. Our analyses showed that denitrifying endosymbionts belonging to the Ca. Azoamicus genus are present in 20%–50% of wastewater treatment plants worldwide. Time-resolved amplicon data from four Danish WWTPs showed high temporal fluctuations in the abundance and composition of the denitrifying endosymbiont community. Twelve high-quality metagenome-assembled genomes of denitrifying endosymbionts, four of which were circular, were recovered. Genome annotation showed that a newly described, globally widespread species, Ca. Azoamicus parvus, lacked a nitrous oxide reductase, suggesting that its denitrification pathway is incomplete. This observation further expands the diversity of metabolic potentials found in denitrifying endosymbionts and indicates a possible involvement of microbial eukaryote holobionts in wastewater ecosystem dynamics of nitrogen removal and greenhouse gas production.

Accelerated global human population growth and the corresponding increased urbanisation and industrialisation have resulted in increased manufacturing of goods, and production and loading of domestic and industrial wastewater overwhelming conventional wastewater treatment plants (CWTPs). The net result has been the release of untreated and partially treated domestic wastewater into water systems posing human health hazards and disturbing aquatic habitat integrity. Considering the severe challenges of wastewater treatment not only in Zimbabwe but in Africa and the world in general, it is prudent to assess the microbial fuel cells (MFCs) as an alternative wastewater treatment method for the CWTPs that have failed to operate efficiently. This purposive literature scoping review aimed to: (a) Examine the concept design and operational efficacy of microbial fuel cells (MFCs), (b) Examine the MFC operational system (c) Outline in brief the evolutionary history and assess the existent prototypes and (d) Establish the drivers and barriers for the uptake of microbial fuel cells (MFCs) from a global and local, Zimbabwe, context. Few prototypes have been utilized in real-world systems; with the majority of them being laboratory-scale based. Although MFCs are effective at treating wastewater, scaling them up is still difficult due to their low power generation. Nonetheless, MFCs' simultaneous wastewater treatment and power generation, low carbon footprint, and reduced sludge production are the main drivers behind their adoption. However, capital and maintenance costs and upscaling remain the major challenges in adopting MFC technology. If MFCs are to be used in developing nations like Zimbabwe, further studies should focus on low-cost materials that guarantee maximum power generation and effective wastewater treatment. To ensure effective wastewater treatment, MFCs should be compatible, and integrated with currently utilized sustainable wastewater treatment systems.