Development of a simple biogas analyzer module (BAM) for real-time biogas production monitoring.

ABSTRACTAnaerobic digestion (AD) relies on the cooperation of specific microbial communities, making it susceptible to process disruptions that could impact biogas production. In this regard, this study presents a technological solution based on the Arduino platform, in the form of a simple online monitoring system that can track the produced biogas profile, named as biogas analyzer module (BAM). The applicability of the BAM focused on monitoring the biogas produced from sugarcane vinasse inoculated with sewage sludge biodigestion processed in mesophilic conditions (38 oC), in a pH range of 6.5-7.5, and following a three-stage operational model: (i) an adaptation (168 h), (ii) complete mixing (168 h), and (iii) bio-stimulation with glycerol (192 h). Then, the lab-made BAM was used to trace the produced biogas profile, which registered a total biogas volume of 8,719.86 cm3 and biomethane concentration of 95.79% (vol.), removing 90.8% (vol) of carbon dioxide (CO2) and 65.2% (vol) of hydrogen sulfide (H2S). In conclusion, the results ensured good accuracy and efficiency to the device created by comparisons with established standards (chromatographic and colorimetric methods), as well as the cost reduction. The developed device would likely be six times cheaper than what is available in the market.

Integrated Biorefinery and Life Cycle Assessment of Cassava Processing Residue-From Production to Sustainable Evaluation.

Commonly known as a subsistence culture, cassava came to be considered a commodity and key to adding value. However, this tuber's processing for starch and flour production is responsible for generating a large amount of waste that causes serious environmental problems. This biomass of varied biochemical composition has excellent potential for producing fuels (biogas, bioethanol, butanol, biohydrogen) and non-energetic products (succinic acid, glucose syrup, lactic acid) via biorefinery. However, there are environmental challenges, leading to uncertainties related to the sustainability of biorefineries. Thus, the provision of information generated in life cycle assessment (LCA) can help reduce bottlenecks found in the productive stages, making production more competitive. Within that, this review concentrates information on the production of value-added products, the environmental impact generated, and the sustainability of biorefineries.

Effective adsorption of diclofenac and naproxen from water using fixed-bed column loaded with composite of heavy sugarcane ash and polyethylene terephthalate.

The contamination of water by pharmaceutical pollutants is a major issue these days due to excessive use of these ingredients in modern life. This study evaluated the adsorption and effectiveness of a low-cost composite prepared from heavy sugarcane ash (HSA) fused with polyethylene terephthalate (PET) and functionalized with iron (Fe3+) in a dynamic system through a fixed-bed column. The solution of synthetic drugs was prepared and placed in a reservoir, using a peristaltic pump the solution is run onto the fixed bed column at a flow rate of 2 mL min-1. Saturation time and adsorption capacity were evaluated by centrifugation and extraction after a regular interval of 2 h from the adsorption column. The samples were analyzed using high-performance liquid chromatography (HPLC) and the data was modeled for quantification. For DIC removal, an adsorption capacity of 324.34 µg. g-1 and a saturation time of 22 h were observed, while the adsorption capacity of NAP was 956.49 µg. g-1, with a saturation time of 8 h. Thus, the PETSCA/Fe3+ adsorbent proved to be quite efficient for removing the pharmaceutical pollutants, with a longer period of operation for DIC removal. These findings suggested that a highly efficient bed column made from a less expensive waste material and could be used to remove hazardous pharmaceutical contaminants.

Adsorptive remediation of naproxen from water using in-house developed hybrid material functionalized with iron oxide.

Every year, a considerable volume of medications is consumed. Because these medications are not entirely eliminated in the sewage treatment plants and impact the surface waterways, the environmental pollution problem arises. This study objective was to evaluate the possibility of using an absorbent material made with of polyethylene terephthalate and sugarcane bagasse ash functionalized with iron oxide (PETSCA/Fe3+) in the removal of naproxen from water. The feasibility of having viable features in becoming an efficient adsorbent was first determined. The batch test was performed, allowing the dose effect, adsorption kinetics, and isotherm models to be evaluated. The determination of naproxen (NAP) concentration in water was analyzed on a high-performance liquid chromatograph and Langmuir method best represented the adsorption isotherm model. PETSCA/Fe3+ adsorbent material demonstrated potential in the naproxen removal at a low cost. The batching process was satisfactory, with 0.30 g of composite being the optimum fit for the system. The adsorption kinetics was determined and described by the pseudo second order model, with an average correlation coefficient (R2) of 0.974. The adsorption system model was best represented by the Langmuir isotherm curve. Moreover, adsorption in the presence of H2O2 had a positive impact on the process, removing 81.9% of NAP, whereas the process without H2O2 did not remove more than 62.0% of NAP. Therefore, because of its good qualities for NAP removal, PETSCA/Fe3+ is recommended as adsorbent material, primarily in small-volume water filtration systems.

Diclofenac removal in water supply by adsorption on composite low-cost material.

This work objective was to evaluate batch adsorption processes using polyethylene terephthalate composite (PTC) material, sugarcane bagasse ash (SBA) functionalized with iron oxide (Fe3+) (PTCSBA/ Fe3+) in the adsorption of 1000 µg  L-1 of diclofenac sodium (DIC) in synthetic solution, simulating water supply. The batch test was started by determining the adsorbent mass (0.1, 0.2, 0.3, 0.4 and 0.5 g) to remove 1000 µg L-1 of DIC, followed by the adsorption kinetics and adsorption isotherm assays, evaluating the reaction rate and adsorption capacity, respectively. The PTCSBA/ Fe3+ mass that had the best efficiency in the DIC removal was 0.3 g, the pseudo second-order kinetic model (PSO) was the one that best fit the study having a determination coefficient (R2) equals to 0.97. The PTCSBA/ Fe3+ has good characteristics for DIC adsorption, achieving a 93% removal rate of sodium diclofenac. The composite is a low-cost adsorbent, 0.08 cents per kilogram of material, becoming a material with satisfactory characteristics for the removal of DIC. Therefore, it is recommended to use PTCSBA/ Fe3+ as adsorbent material in small water filter systems in order to remove DIC due to the low cost of the composite.

Sequential degradation of raw vinasse by a laccase enzyme producing fungus Pleurotus sajor-caju and its ATPS purification.

This study evaluated simultaneously the raw vinasse degradation, an effluent from the sugar-alcohol industry, the laccase production by Pleurotus sajor-caju and its purification using aqueous two-phase systems (ATPS). To improve laccase production, different concentrations of inducers (ethanol and CuSO4) were added. The higher laccase production promoted an increase of 4-fold using 0.4 mM of CuSO4 as inducer, with maximum enzymatic activity of 539.3 U/L on the 3rd day of fermentation. The final treated vinasse had a decolorization of 92% and turbidity removal of 99% using CuSO4. Moreover, the produced laccase was then purified by ATPS in a single purification step, reaching 2.9-fold and recovered ≈ 99,9 %, in the top phase (PEG-rich phase) using 12 wt% of PEG 1500 + 20 wt% of citrate buffer + enzyme broth + water, at 25 °C. Thus, an integrated process of vinasse degradation, laccase production and purification with potential industrial application was proposed.