Persistent product inhibition and downstream separation challenges limit butyric acid fermentation efficiency, necessitating integrated recovery strategies. This study screened non-ionic surfactants (NISs) for selective recovery of butyric acid in abiotic mixed-acid systems and evaluated the most effective surfactant in extraction-integrated fermentation (biotic) under varying timing of addition, reaction times, and agitation speeds. Among the NISs tested, EcosurfTM EH-3 showed superior performance. In a 25% pure butyric acid solution, it achieved 94.25% recovery with a distribution coefficient (Kd) of 14.02. In a 20% butyric–5% acetic acid mixture, it attained 72.59% butyric acid recovery with a Kd of 3.18 and selectivity of 9.35. This performance was attributed to balanced hydrophobic–hydrophilic interactions, favorable cloud point behavior, and structural compatibility. Integration of EcosurfTM EH-3 into extractive fermentation enhanced butyric acid yield versus conventional fermentation (0.28 g/g), reaching 0.38 g/g when inoculation preceded surfactant addition. Butyric acid recovery (77.02%), Kd (3.50), and selectivity (7.60) were also improved, while acetic acid formation was reduced and microbial activity was maintained. At 60 rpm agitation, reaction time significantly affected performance, with 48 h identified as the best condition, balancing yield, Kd, recovery, and selectivity, beyond which improvements were insignificant. On the other hand, at a fixed 48-h reaction time, moderate agitation (100 rpm) further improved performance, achieving 0.42 g/g yield, 83.61% recovery, Kd of 5.10, and selectivity of 16.04. Across all conditions, extractive fermentation outperformed conventional fermentation, establishing EcosurfTM EH-3 as a promising surfactant for efficient butyric acid production and selective recovery.

There has recently been a rapid growth of domestic cadmium-tellurium (CdTe) photovoltaic (PV) solar panel production, mainly driven by the clean energy transition toward net-zero emissions. At the same time, the limited availability of tellurium (Te) underscores the importance of recovery practices for sustainable Te supply in the U.S. Herein, Mg-Al layered double hydroxide (LDH) demonstrated a high adsorption capacity for tellurium anion (TeO3 2-), offering high selectivity, efficiency, and recyclability in aqueous solution. Mg-Al LDH was synthesized via coprecipitation, and after calcination, a positive surface charge was developed on the adsorbent, resulting in surface adsorption and intercalation of tellurite anions (TeO3 2-) into the interlayer spaces of CLDH through electrostatic attraction. The synthesized calcined LDH (CLDH) achieved a maximum adsorption capacity of 161.8 mg/g at neutral pH, and 93% of adsorbed Te was recovered through NaOH-induced desorption. Therefore, Mg-Al LDH offers a potential solution for tellurium recovery, thereby promoting domestic CdTe solar panel production for a clean energy supply chain.

Sulfur compounds are extremely toxic and highly corrosive (e.g. mercaptans and hy-drogen sulfide) and are commonly found in natural gas streams and can be damaging even if only minute amounts are present in natural gas streams because it can affect the quality of fuels and cause failure of downstream equipment. Many metal oxides have been used as adsorbent/catalyst for the removal of sulfur compounds from natural gas; however, they vary greatly in how well they can remove sulfur compounds, and the underlying mechanisms of these processes are still not fully understood. Therefore, the purpose of this study was to examine the adsorption/removal performance of many metal oxides on halloysite support at the same conditions to identify the relationship between the electronic properties (specifically bandgap energy) and breakthrough time (a measure of removal/adsorption efficiency). The experimental results indicate large differences in the adsorption performance of the studied oxides and some commercial metal oxides had lower than expected adsorption performance. Conversely, all the studied oxides with the lowest bandgap energies showed higher sulfur compound (e.g. ethyl mercaptan) uptake and longer breakthrough times indicating that the electronic properties of the oxides are important in determining the strength of interaction be-tween the sulfur compounds and the metal oxide. The experimental results from this study will provide understanding of why certain metal oxides may not perform as good as others during natural gas desulfurization and assist in developing a systematic method for selecting adsorbents/catalysts that will improve the overall natural gas desulfurization process. Furthermore, incorporating palladium oxides into the base catalyst formulation achieved a maximum breakthrough time of 630 minutes at 25°C 200 psi, and 36 mL/min. These findings provide critical insights for developing catalysts that integrate metal oxides to enhance adsorption efficiency while reducing hazardous byproducts during sulfur compounds (e.g. mercaptans and hydrogen sulfide) removal from natural gas.

The growing demand for environmentally benign weed control has renewed interest in fast-acting, non-persistent contact herbicides such as nonanoic (pelargonic) acid. Oxidative cleavage of oleic acid derived in plant oils is an industrially developed mode of production of nonanoic acid, a commercially established contact herbicide, which establishes supply chain inquiry on agricultural land and food markets. In this study, the brewery wastewater was evaluated as a carbon source for microbial lipid production and further nonanoic acid production. Yarrowia lipolytica and Rhodotorula glutinis were grown under controlled C:N ratios to promote lipid production. Both microorganisms produced lipids rich in C18 fatty acids, and Y. lipolytica had a fatty acid profile, which is largely dominated by oleic acid, similar to the fatty acid profile of canola oil. Nonanoic acid was found in all cultivation conditions after direct transesterification and ozonolysis with specific yields of biomass ranging from 3.46 to 9.39 mg g−1 DCW and of lipid ranging from 18.45 to 56.68 mg g−1 lipid. The results of the statistical analyses showed that there was significant strain × medium interaction effects, which suggested that nonanoic acid production was not only dependent on the microbial biomass or lipid content, but also on the wastewater source. The counterion was seen to influence the formulation properties, as illustrated in the amphiphilic interaction analysis and phytotoxicity screening. The results demonstrate that brewery wastewater can serve as a substrate for microbial lipid production and subsequent ozonolysis-based nonanoic acid generation, while highlighting the need for further improvements in lipid productivity, ozonolysis efficiency, and overall process performance.

Methanotrophs are aerobic bacteria capable of converting methane (CH4) into valuable biomaterials (e.g., lipids, proteins, bioplastics) while simultaneously mitigating greenhouse gas emissions. Wastewater treatment plants (WWTPs) represent major sources of CH4 emission and generate sludge that pose environmental challenges. Integrating methanotroph-based biomaterial production process into existing WWTPs offers an opportunity to valorize on-site biogas and wastewater-derived resources. This work investigated methanotroph enrichment from activated sludge using synthetic wastewater (SW) as a cultivation medium to support subsequent CH4 bioconversion to useful biomaterials. This enrichment study was conducted in two phases: Phase 1 evaluated the effects of media type, CH4:air volume ratio, and initial pH, while Phase 2 optimized nutrient composition (i.e., NH4+ and Cu2+ concentrations) to enrich methanotroph population in the system. Results showed that CH4 consumption is mainly affected by CH4:air ratio and initial pH, whereas the biomass lipid content is primarily influenced by media type and CH4:air ratio. Under the most suitable conditions (SW medium at pH = 6.8 and CH4:air ratio = 1:1), higher biomass lipid content was observed alongside an increase in Type I/X methanotroph abundance. NH4+ addition enhanced biomass lipid content and promoted the growth of Type I/X methanotrophs while increased Cu2+ concentrations selectively enriched Type II populations, demonstrating the role of nutrient composition in shaping community dynamics. This enrichment strategy could potentially reduce CH4 emissions by similar to 23% while providing a sustainable source of biomaterials. Overall, this work elucidates key drivers for methanotroph enrichment and highlights the need for further study to support integration in WWTPs.

This study evaluated the feasibility of growing Chlorella vulgaris using Mars in situ resources (soil/regolith and CO2) and human-derived waste streams (urine and CO2). In particular, the goal was to determine the effects of cultivation media components—urine simulant, regolith extract, and CO2 levels—on microalgal growth. Results show that the interaction of urine simulant and regolith extract significantly affected microalgal biomass productivity (MBP), with the highest MBP of 0.27 g/l-d observed in the urine-only medium, highlighting the importance of nitrogen and phosphorus. CO2 level variations had minimal impact on MBP. Higher N and P concentrations in less diluted urine improved microalgal growth and nutrient use, emphasizing nitrogen’s critical role for high-lipid-producing species like C. vulgaris. Also, the study observed that regolith extract negatively affected MBP due to CaCO3 formation, possibly causing cell aggregation and impaired cellular functions. However, regolith extract significantly enhanced CO2 uptake, 10-fold higher than the urine-only medium, attributed to higher utilization of carbonic anhydrase and improved photosynthetic rate. Despite this, MBP remained lower in regolith-containing media due to simultaneous CO2 to CaCO3 conversion. Overall, the urine-only medium with higher initial N and P but low CO2 levels yielded the highest O2 production and a photosynthetic quotient of 1.04. If a higher MBP is preferred, CO2 enrichment in the same setup is recommended. In conclusion, C. vulgaris can effectively utilize Mars resources and human-derived waste for biomass production and air revitalization, supporting sustainable life support systems for future Mars missions and long-term space habitat applications.

Lithium has seen a surge in global demand, primarily driven by the growing interest in electric vehicles as a sustainable transportation solution and by advancements in portable electronics. Traditional lithium production methods, i.e., mining and evaporitic processes, have inherent sustainability issues due to environmental risks and significant process lead times. In response, researchers have been actively investigating rapid and sustainable alternatives for extracting this critical element from brines using direct lithium extraction (DLE) processes. Many techniques have been proposed including adsorption, ion-exchange, precipitation, and solvent extraction, and recently, many of these processes have been demonstrated industrially and are approaching commercialization. This paper comprehensively reviews these DLE techniques and points out the ones that can be used synergistically for a complete lithium production treatment train. Lithium extraction technology is analyzed from a macroscopic perspective, filling a sufficient literary gap by addressing practical challenges and considerations that arise when translating scientific knowledge into real-world operations. This holistic examination provides a greater understanding of the intricacies and interconnectedness of unit operations within the extraction processes. Furthermore, technical and economic data are evaluated for ongoing industrial projects proving that commercialization is feasible. This work advances the knowledge of the ever-evolving lithium extraction process by identifying advantages, disadvantages, key challenges, and potential opportunities for the production of a sustainable lithium supply on an industrial and engineering scale.

The increasing lithium demand for use in energy storage and other industrial applications necessitates efficient recovery from low-grade aqueous resources, such as subsurface and surface brines. This study presents a novel hydrogen peroxide pretreatment strategy to create hydrogen titanate lithium-ion sieves with enhanced surface hydroxylation and improved selectivity for lithium recovery over commonly found brine inorganic constituents. The Li2TiO3 precursor was hydrothermally treated with alkaline H2O2 and subsequently acid-leached to yield the modified lithium-ion sieve (HP-HTO). Spectroscopic analysis confirmed a higher density of surface-OH groups on the HP-HTO surfaces. X-ray diffractograms revealed enhanced ordering of the (002) crystal plane, facilitating improved lithium-ion (Li+) diffusion through the titanate layers. Consequently, HP-HTO exhibited over 20 % higher Li+ uptake across the entire isotherm range, with a maximum of 61.02 mg Li+/g compared to 49.73 mg Li+/g for conventional H2TiO3. The Li+ uptake follows Avrami kinetics and best-fitted using the Freundlich isotherm model, indicating surface heterogeneity and a distribution of binding energies, consistent with the structural nature of titanate materials. The effects of pH were examined in buffered systems to maintain a constant chemical driving force and eliminate the confounding influence of pH drop during Li+ uptake. Selectivity studies were conducted in binary-ion and mixed-ion systems at equimolar concentrations of Li+, Na+, K+, and Ca2+ to isolate competitive effects and better reflect true ion selectivity. Selectivity factors for Li+ over individual competing cations demonstrated 24-161 % improvement with the hydrogen peroxide treatment. This is the first reported application of oxidative treatment in lithium-ion sieve synthesis. The facile peroxide treatment offers a scalable and efficient strategy for optimizing lithium-ion sieves for enhanced lithium extraction from complex brines.

Societies are aiming to have a higher ecological consciousness in wastewater treatment operations and achieve a more sustainable future. With this said, global demands for larger quantities of resources and the consequent waste generated will inevitably lead to the exhaustion of current municipal wastewater treatment works. The utilization of biosolids (particularly microbial proteins) from wastewater treatment operations could generate a sustainable bio-adhesive for the wood industry, reduce carbon footprint, mitigate health concerns related to the use of carcinogenic components, and support a more circular economic option for wastewater treatment. A techno-economic analysis for three 10 MGD wastewater treatment operations producing roughly 11,300 dry pounds of biosolids per day, in conjunction with co-feedstock defatted soy flour protein at varying ratios (i.e., 0%, 15%, and 50% wet weight), was conducted. Aspen Capital Cost Estimator V12 was used to design and estimate installed equipment additions for wastewater treatment plant integration into an urban biorefinery process. Due to the mechanical attributes and market competition, the chosen selling prices of each adhesive per pound were set for analysis as USD 0.75 for Plant Option P1, USD 0.85 for Plant Option P2, and USD 1.00 for Plant Option P3. Over a 20-year life, each plant option demonstrated economic viability with high NPVs of USD 107.9M, USD 178.7M, and USD 502.2M and internal rates of return (IRRs) of 24.0%, 29.0%, and 44.2% respectively. The options examined have low production costs of USD 0.14 and USD 0.19 per pound, minimum selling prices of USD 0.42–USD 0.51 per pound, resulting in between 2- and 4-year payback periods. Sensitivity analysis shows the effects biosolid production fluctuations, raw material market price, and adhesive selling price have on economics. The results proved profitable even with large variations in the feedstock and raw material prices, requiring low market selling prices to reach the hurdle rate of examination. This technology is economically enticing, and the positive environmental impact of waste utilization encourages further development and analysis of the bio-adhesive process.

Energy security is a growing societal and industrial concern that leads research and development toward more sustainable options. Biogas, a bio-alternative to conventional fuels, is a product generated from the anaerobic digestion of organic matter. This source of fuel production is more environmentally friendly compared to traditional fossil fuels, leading to a lower carbon footprint, higher air quality, and the promotion of a circular economy. Impurities of raw biogas, such as carbon dioxide, hydrogen sulfide, and other trace contaminants, make biogas conditioning necessary for most applications. In addition, biogas upgrading, technologies furthering biogas purity, is an important factor in the production of biomethane, a sustainable biofuel known more commonly as renewable natural gas (RNG). Diversifying fuel sources and providing energy sustainability while mitigating negative environmental effects makes RNG an attractive alternative to conventional natural gas. This document, Part I, provides an overview of current technologies related to biogas conditioning, such as sorption, oxidation, and biological treatments aimed at the removal of a wide variety of contaminants. Processes developed for biogas upgrading are also discussed, including physical/chemical absorption, pressure swing adsorption, and membrane separation. The focus of upgrading applies approaches in meeting a higher quality biofuel by further carbon dioxide exclusion to ease pipeline transport and increase combustion efficiency. These technologies present the core foundation of processes in the production of RNG; however, all face inherent challenges that deem further research and development a requirement for global adoption. The biggest challenges are either in the cost of reaching higher purities or the inability to do so without other operations. Thus, in conjunction with this document, emerging and developing technologies are provided in a separate analysis deemed Part II. Together, these documents offer a comprehensive understanding of current practices and growing technological developments.

The rising demand for bio-based volatile organic acids (VOAs) like butyric acid is driven by consumer preference for natural products, but recovery from fermentation broth remains inefficient. To address this challenge, this study investigates non-ionic surfactants (NISs) for butyric acid recovery via aqueous two-phase (ATP) extraction, aiming to identify the most suitable NIS and evaluate its economic potential. From seven pre-selected NISs based on properties, four NISs (Makon® NF-12, Ecosurf™ EH-3, Nonidet™ RK-18, Triton™ X-45) were tested at varying initial butyric acid concentrations (10%, 15%, 20%, 25% w/w) and extraction times (1 h, 5 h, 8 h, 24 h). Results show that Ecosurf™ EH-3 performed best, achieving 79.15% recovery and a partition coefficient (Kp) of 7.49. Statistical analysis also revealed that only the surfactant type significantly affected extraction efficiency. Economically, Ecosurf™ EH-3 was the most cost-effective, with the lowest break-even selling price of 11.28 USD/kg over a seven-year payback period, though still above the market price of 2–2.5 USD/kg. Scaling up from 1000 to 20,000 kg/h with high-acid broth (4.30% w/w) could improve market competitiveness, but low-acid broths remain less viable. Improved extraction efficiency and lower surfactant use are essential to reduce costs below 2 USD/kg and enhance commercial potential.

Nonionic surfactant (NIS)-mediated extraction offers a promising approach to recover volatile organic acids like butyric acid from fermentation broths but often suffers from poor phase separation and selectivity. This study examines how salt type, concentration, and their interaction influence butyric acid recovery and distribution or partition coefficient (K p) in an Ecosurf EH-3 NIS system. Results show that higher salt concentrations generally enhanced extraction of the acid with anion identity exerting the strongest effect, complemented by cation contributions, consistent with the Hofmeister series. Notably, FeSO47H2O and KH2PO4 exhibited synergistic salting-out effects. Response surface analysis identified optimal abiotic conditions (0.67 M KH2PO4 and 0.28 M FeSO47H2O), achieving 92.60% recovery and a K p of 6.70. However, biotic tests revealed that moderate salt levels (0.20 M KH2PO4 and 0.05 M FeSO47H2O) best maintained Clostridium tyrobutyricum viability while delivering 70.97% butyric acid recovery, a K p of 4.25, and a selectivity of 4.91, demonstrating the potential of salt augmentation for integrated fermentation-extraction systems.

This study explores the feasibility of fabricating calcium carbonate (CaCO3)-reinforced bricks using the carbonic anhydrase (CA) enzyme from Chlorella vulgaris biomass and resources available on Mars, such as carbon dioxide (CO2) and regolith. Microalgal biomass was cultivated under varying conditions: CO2 feed concentrations (0.04% or 5% v/v), human urine simulant dilution factors (UDFs) (61 or 121), and the presence of regolith extract (RE) in the nutrient medium. Results showed that CO2 and RE significantly influenced the production of microalgal biomass, which contained substantial CaCO3. The highest total biomass productivity (TBP) of 1.39 g/L-day was achieved in air-fed RE-containing media with UDF = 61, although this condition also yielded the most cell debris. In contrast, the most viable microalgal biomass (0.34 g/L-day) was produced in urine-only media with UDF = 61 supplemented with 5% CO2. For CaCO3 productivity, the highest (0.0164 g/L-day) was observed in RE-containing media (UDF = 61) with 5% CO2, despite having the lowest TBP (0.07 g/L-day). This CaCO3-rich microalgal biomass was used as the enzyme source for brick fabrication, resulting in bricks with a compressive strength of 542.83 psi. The low solubility of biomineralization-derived CaCO3 during enzyme extraction enhanced mineral availability in the bricks, improving the compressive strength and reducing the surface porosity. Although the highest brick compressive strength obtained in this work was lower than the recommended strength under reduced gravity (870 psi), the findings of this research indicate that Mars-based construction using in situ resources is feasible. Further optimization is essential to meet the structural demands of Mars' habitats.

Perfluorocarboxylic acids (PFCAs) are emerging organic pollutants posing a threat to human health and the environment. This study investigates the efficacy of polyethyleneimine-modified biochar (BC-PEI) as an adsorbent for removing PFCAs from a mixed solute system, focusing on competitive adsorption among PFCAs with varying chain lengths. It includes perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA), hexafluoropropylene-oxide-dimer-acid (GenX), and perfluorobutanoic acid (PFBA). BC-PEI (1:1) (wPEI/wBC = 1) exhibited the highest adsorption capacities for PFOA, PFHxA, GenX, and PFBA at 1.302, 0.850, 0.711, and 0.397 mmol/g, respectively. It follows the Sips isotherm (Langmuir-Freundlich isotherm) model, which becomes Langmuir at high concentration and Freundlich at low concentration. Surface functional groups, as well as electrostatic and hydrophobic interactions, influenced the adsorption mechanism. Long-chain PFCAs demonstrated higher adsorption capacities due to stronger hydrophobic interactions, while short-chain PFCAs were primarily adsorbed via electrostatic interactions. Kinetics data were best described by the pseudo-second-order (PSO) model, with surface adsorption and minor micropore contributions governing the process. The presence of humic acid reduced the adsorption capacity by competing for adsorption sites. The background ions in the aqueous matrix further diminished capacity due to double-layer compression. Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) confirmed PFCAs adsorption onto BC-PEI. These findings underscore the potential of BC-PEI as a promising adsorbent for PFCA remediation in wastewater systems, highlighting its engineering applications.

Renewable natural gas is an innovative alternative fuel source that has the potential to integrate seamlessly into the current energy and fuel sector. In addition, growing concerns related to energy security and environmental impact are incentivizing the development of RNG technologies. In conjunction with this document, current technologies related to biogas conditioning and biogas upgrading were covered in a separate analysis deemed Part I. With the current technologies, however, issues such as compositional quality, combustion efficiency, and high operational costs still need to be addressed before RNG can reach its true capability in use. Recent innovations have focused on optimizing techniques and introducing new methods to maximize methane yield and purity while minimizing costs and energy consumption. This document, Part II, provides an overview of emerging technologies related to further biogas upgrading, such as cryogenics, methane enrichment, and hybrid treatments, aimed at increasing cleaned biogas purity. Processes in development are also discussed, including industrial lung, supersonic separation, chemical hydrogenation, hydrate formation, and various biological treatments. The benefits of these advancements are increased purity for the ability to pipeline renewable natural gas in existing infrastructure, help industries reach sustainability goals, and contribute to a more resilient energy system. Together, Parts I and II offer a comprehensive understanding of both current and future technological developments.

Methyl mercaptan is a sulfur-based chemical found as a co-product in produced natural gas and it causes corrosion in pipelines, storage tanks, catalysts, and solid adsorption beds. To improve the quality of methane produced, researchers have studied the use of metal oxides and aluminum silicates as catalysts for removing mercaptan. However, there are restrictive limitations on the efficiency of metal oxides or aluminum silicates as adsorbents for this application. Therefore, this study investigated the performance of these materials in a fixed-bed reactor with simulated natural gas streams under various operating conditions. The testing procedure includes a detailed assessment of the adsorbent/catalysts by several techniques, such as Braeuer–Emmett–Teller (BET), Scanning Electron Microscope (SEM), Energy-Dispersive X-ray Spectrometry (EDS), and X-ray Photoelectron Spectroscopy. The results revealed that metal oxides such as copper, manganese, and zinc performed well in methyl mercaptan elimination. The addition of manganese, copper, and zinc oxides to the aluminum silicate surface resulted in a sulfur capacity of 1226 mg S/g of catalyst. These findings provide critical insights for the development of catalysts that combine metal oxides to increase adsorption while reducing the production of byproducts like dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) during methyl mercaptan removal.

Adhesive formulations derived from sustainable feedstocks, like waste-activated sludge and biosolids from wastewater treatment plants, are developed due to protein-based adhesives receiving attention for their low-cost, resourcefulness, and minimal ecological footprint. The protein composition and associated dynamic changes of the adhesive formulations were studied via gel permeation chromatography, which detailed a molecular size distribution of 8.72 × 105 g/mol for the adhesive formulation and 6.89 × 103 g/mol for the dewatered biosolid base fraction, which confirms the formation of multiple protein functional groups combining to form the larger adhesive molecules. Further analysis determined the types of proteins present in the dewatered biosolids as glutelin, prolamin, globulin, and albumin proteins, with the glutelin proteins as the most prevalent, as thus likely responsible for adhesive formation. The rheological properties of the novel protein adhesive were also studied to interpret the structure of the adhesives, which detailed the findings of viscoelastic properties and flow behaviors of each adhesive in relation to the wastewater treatment plant sample location, which yielded higher flow points, storage moduli, and loss moduli for the dewatered biosolids in comparison to the waste-activated sludge and biosolid adhesives, which correlates with the higher solids content of the dewatered biosolids and potentially cell rupturing when exposed to filtration stress.

An increase in the generation of waste within cities is unavoidable due to the increasing global population growth, particularly in urban areas. Municipal wastewater treatment plants (WWTPs) in these urban areas are being pushed to their design limits resulting in issues with WWTP residual management. This paper reviews potential applications of transitioning a municipal WWTP into an urban biorefinery for converting wastes into various value-added chemicals and energy. Primary WWTP-based residuals produced are waste-activated sludge, biosolids, grit, and effluent. These components are becoming viable feedstocks for producing many potential products and can be recovered for commercial purposes as opposed to simple disposal. Example products include chemicals, energy, and transportable biofuels. An advantage to biorefinery operations composed of WWTPs is that they provide greener solutions while posing little to no threat to the environment. There has also been an increasing interest in co-feedstocks to WWTPs, such as municipal solids, food wastes, agriculture wastes, and lignocellulosic biomass, which can enhance product yields while providing sustainable management solutions to these additional waste streams. Municipal wastewater influents generated within the USA have a chemical energy potential of 1.3 MJ/person/day which represents about 4