Digestion Treatment Research Articles

Growth of microalgae and cyanobacteria consortium in a photobioreactor treating liquid anaerobic digestate from vegetable waste

This research examines the biological treatment of undiluted vegetable waste digestate conducted in a bubble column photobioreactor. Initially, the bioreactor containing 3N-BBM medium was inoculated with Microglena sp., Tetradesmus obliquus, and Desmodesmus subspicatus mixture with a density of 1.0 × 104 cells/mL and the consortium was cultivated for 30 days. Then, the bioreactor was semi-continuously fed with liquid digestate with hydraulic retention time (HRT) of 30 days, and the treatment process was continued for the next 15 weeks. The change in the microalgal and cyanobacterial species domination was measured in regular intervals using cell counting with droplet method on a microscope slide. At the end of the experiment, Desmonostoc sp. cyanobacteria (identified with 16S ribosomal RNA genetical analysis) as well as Tetradesmus obliquus green algae along with Rhodanobacteraceae and Planococcaceae bacteria (determined with V3–V4 16sRNA metagenomic studies) dominated the microbial community in the photobioreactor. The experiment demonstrated high treatment efficiency, since nitrogen and soluble COD were removed by 89.3 ± 0.5% and 91.2 ± 1.6%, respectively, whereas for phosphates, 72.8 ± 2.1% removal rate was achieved.

Microbial removal of nutrients from anaerobic digestate: assessing product-coupled and non-product-coupled approaches.

Although anaerobic digestate contains >90% water, the high nutrient content of digestate makes it economically and technically intractable to treatment by existing wastewater treatment technologies. This study separately assessed the feasibility of nutrient removal from digestate by Rhizopus delemar DSM 905 and a culture of phosphate-accumulating organisms (PAOs). With Rhizopus delemar DSM 905, we investigated concomitant nutrient removal from digestate-supplemented medium and fumaric acid production, as a potentially economical strategy for digestate treatment. Following the cultivation of R. delemar DSM 905 in a fermentation medium containing 25% (v/v) digestate, the concentrations of Al, Cr, Cu, Fe, K, Mg, Mn, Pb, and Zn reduced 40, 12, 74, 96, 12, 26, 23%, ~18, and 28%, respectively. Similarly, the concentrations of total phosphorus, total nitrogen, phosphate (PO4-P), ammonium (NH4-N), nitrate (NO3-N), and sulfur decreased 93, 88, 97, 98, 69, and 13%, respectively. Concomitantly, cultures supplemented with 25 and 15% (v/v) digestate produced comparable titers of fumarate (~11 and ~ 17 g/L, respectively) to the digestate un-supplemented control cultures. With PAOs, we assessed the removal of total phosphorus, total nitrogen, PO4-P, and NH4-N, of which the concentrations reduced 86, 90%, ~99, and 100%, respectively in 60% (v/v) digestate. This study provides additional bases for microbial removal of excess nutrients from anaerobic digestate, with the potential to engender future water recovery from this waste stream that is currently largely recalcitrant to treatment.

Biogas Production from Plantain and Yam Peels: Modelling using Response Surface Methodology

The world’s growing demand for energy and our concern to preserve the environment have prompted research into alternative sources of energy. Renewable energy from biomass is one such opportunity. The aim of this study is to model the production of biogas from the anaerobic digestion of plantain and yam peelings and cattle dung. A characterisation of these residues showed their good suitability for methanisation with good moisture contents (˃70%), high volatile solids contents (˃75%) and C/N ratios of between 20 and 30. In addition, methanisation trials under mesophilic conditions following a mixing plan generated quantities of biogas ranging from 128 to 565 mL with CH4 contents of between 54.03 and 72.98%. The digester made up of 1/6 plantain peels + 2/3 yam peels + 1/6 cattle dung gave the best biogas yield with 565 mL for 67.52% CH4. The model established from these results is highly significant with an F value (1268.01) having a probability significantly lower than 0.05. In addition to the coefficients R2 (0.9994) and R2 (0.9986) which adjust are very close to unity, there is a good correlation between the experimental results and those predicted. This prediction model is therefore reliable for explaining biogas production. However, further study of the kinetics of anaerobic digestion and biogas treatment remains important.

Unveiling microplastic spectral signatures under weathering and digestive environments through shortwave infrared hyperspectral sensing

Microplastic (MP) pollution presents a novel challenge for marine environmental protection, necessitating comprehensive and long-term monitoring and assessment approaches. Environmental MPs can undergo weathering and microorganism-related digestive processes, altering their original surface properties and chemical structure, thus complicating their quantification and identification. This study aims to establish a comprehensive hyperspectral database for weathered and digestion-degraded MPs, using a wide variety of polymer types collected as either virgin particles or commercial products (within a size range of approximately 3 mm), and to investigate the impact of these processes on their spectral characteristics. Polypropylene (PP) and polyethylene (PE) MPs exhibited significant responses to weathering treatment, as indicated by the formation of new characteristic peaks or slight peak shifts around 1679–1705 nm, which can be attributed to the formation of carbonyl and vinyl functional groups through Norrish reactions. Similarly, polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), and polystyrene (PS) MPs demonstrated notable degradation following digestive treatment, as evidenced by the emergence of new absorption peaks at approximately 1135–1165 nm, possibly associated with alterations involving carbonyl and vinyl functional groups. The results were further validated based on their comparable spectral characteristics of the resultant MPs to reference polymers and possible additives, considering a reasonably accurate match of approximately 80% for the studied MP samples. This study showcases the significant advantage of using shortwave infrared hyperspectral sensing for rapid identification of virgin and exposed MPs with a relatively large scan area after a simple sample preparation. This approach, combined with other complementary characterization techniques, shall provide highly throughput results for MPs identification. This research provides valuable insights into the features extracted from environmental MPs and establishes a foundation for improving their classification efficiency for environmental applications.

Lactoferrin-polyphenol composite nanocoating with enhanced chemical stability and cell-compatibility

Lactoferrin is a functional whey protein that exhibits beneficial bioactivities to human health. To utilize the wide range of lactoferrin's biomedical advantages, much effort has been devoted to developing lactoferrin coating strategies. However, lactoferrin coating has been still limited to the conventional protein modification techniques, which hamper the practical applications of lactoferrin. Here, we demonstrate lactoferrin composite nanocoating by layer-by-layer assembly with lactoferrin and Fe(III)-tannic acid complex. The simple immersive processes are able to deposit lactoferrin composite nanolayers on planar substrates with precise thickness tuneablility. Also, the optimized deposition condition for lactoferrin composite nanocoating is applicable to particulate substrates. Further, lactoferrin composite nanocoating shows enhanced nanofilm stability against pH changes and digestive enzyme treatments, and improves cell compatibility greatly, compared to that of Fe(III)-TA complex. We envisage that lactoferrin composite nanocoating not only paves the way for exploiting full potential of lactoferrin's bioactivities, but also leads to stimulating the tailored design of composite nanomaterials containing multiple enzymes for customized applications in nanomedicine and nanobiosensor.

DEVELOPMENT OF TECHNOLOGY FOR TREATMENT OF WASTEWATER DIGESTAT FROM THE FOOD INDUSTRY

This article proposes a hybrid technological scheme for dewatering the digestate of wastewater from the food industry, further cleaning the obtained filtrate after dehydration with the possibility of returning it to the technological chain for reuse. At least ten different derivative products can be obtained from digestate, including liquid/solid fraction, granules obtained from both solid and liquid fractions, and analogues of commercial synthetic fertilisers: ammonium sulphate, ammonia water, magnesium ammonium phosphate (struvite). The purpose of the experimental studies was to choose an appropriate process for treating digestate of food production wastewater to solve the problem of increasing the amount of sediment and the formation of digestate. The investigated digestate treatment processes include the next: chemical conditioning (dosing of flocculants and coagulants), mechanical dewatering using multi-disc technology (with ESMIL MDQ multi-disc screw press), two stages of membrane separation (using reverse osmosis (RO) membranes, vibrating shear process (VSEP), zwitterionic (ZI) membrane). The cake separated after the dehydration stage can be processed in bulk or pallets with 10–35% dry matter content and used as fertiliser. Due to the high viscosity of the initial digestate, the technological scheme provides for its dilution before the dehydration stage. Dilution occurs with the purified filtrate after the membrane purification stage. The effectiveness of dehydration on cake dryness showed worse results than expected but deserves further investigation if this parameter is significant. Using an additional stage of filtrate purification on RO membranes is efficient and appropriate if high-quality purified water is required. The cleaning process can be stopped at any stage, depending on the cleaning needs. The obtained results regarding the efficiency of the cleaning process after RO membranes showed the following values for the main pollutants: COD – 98.43%, ammonium nitrogen – 99.35%, and phosphates – 99.99%. Keywords: digestate, sludge conditioning, coagulant, flocculent, dehydration, membrane purification, cake, permeate.

On-farm use of recycled liquid ammonium sulphate in Southwest Germany using a participatory approach

AbstractFor political and environmental reasons, there is an urgent need for alternatives to energy-intensive synthetic fertilizers. One solution is the targeted recycling of nutrients within agriculture. In this study, liquid ammonium sulphate (LAS) as a recycling product derived from digestate treatment was compared to calcium ammonium nitrate, manure and original digestates in an on-farm experiment using a participatory approach. Based on regular meetings with the farmers involved, a flexible experimental design was developed which integrated the fertilization legislation and the farmers’ operational structures already in place, such as crop rotation, available application techniques and manure management demands. The aim was to achieve both implementation practicability and acceptance of the study results by the farmers. Results from the year 2020 showed that LAS applied with three-jet nozzles in barley and wheat had significantly lower yields than the other fertilizers. Applied with a slurry tanker trailing shoe applicator in 2021, LAS had comparable yields to the other fertilizers in maize (51.2 t ha−1) and comparable yields to digestate in rapeseed (4.4 t ha−1). Application techniques that minimize environmental impacts and lower the LAS pH could potentially increase the effectiveness of the fertilizer. We recommend that farmers use this fertilizer not as a single solution but as a mineral compensatory fertilizer in addition to organic fertilizers following local fertilizer legislation. In this case, LAS could potentially substitute calcium ammonium nitrate (CAN).

Anaerobic digestion + pyrolysis integrated system for food waste treatment achieving both environmental and economic benefits

Waste-to-energy technologies for food waste (FW) and digestate treatment face environmental and economic barriers including pollutant emission and practical application concerns. This study investigated environmental impacts and economic feasibility of four scenarios to dispose 1 ton FW by life cycle assessment: Scenario A: mesophilic anaerobic digestion (AD) with digestate for biofertilizer; Scenario B: thermophilic AD with digestate for biofertilizer; Scenario C: mesophilic AD combining with digestate for 400 °C pyrolysis; and Scenario D: thermophilic AD combining with digestate for 700 °C pyrolysis. Scenario D was recommended for FW treatment especially for climate change, fine particulate matter formation, and Fossil depletion credits. Electrical recovery was identified as the most contributing and sensitive factor based on uncertainty and sensitivity analysis. Optimizing electrical generation efficiency from 39 % to 44 % benefited all 17 environmental categories through scenario analysis. Furthermore, Scenario D showed an economic advantage over the other scenarios, which was attributed to digestate post-treatment by 700 °C pyrolysis. This study provided a comprehensive reference for FW and digestate management.

Overcoming germination constraints in seven grass species for seed‐based restoration in the Australian monsoonal tropics

The increasing reliance on native seeds for ecological restoration requires the understanding of seed traits across each species, and the testing of novel processing approaches to optimize germination outcomes. Knowledge regarding Australian native seeds is critical due to the high proportion of species manifesting some degree of seed dormancy. The evaluation of approaches to overcome dormancy and identify optimal conditions for promoting germination in native species has significant applications in the restoration of degraded ecosystems. Grasses are an important component of ecosystems in the Australian monsoonal tropics, a bioregion which covers much of northern Australia, yet they are often forgotten or poorly represented when used in restoration. We investigated the effect of seed processing technique and smoke‐based stimulants on the germination of seven species from the Kimberley region, testing three different hypotheses: (1) florets germinate less than extracted caryopses; (2) acid digestion treatments with different exposure times can enhance germination; and (3) smoke‐based treatments can increase both germination and germination speed. Floret removal was generally helpful in improving germination, whereas the response to acid and smoke‐based treatments was varied. Brief acid exposure produced no to low germination improvements, whereas longer acid treatments showed contrasting results, with some species showing significant germination increase and others showing a severe reduction in germination rate. The only species showing a clear positive germination effect of smoke‐based treatments was Triodia bynoei. These results are helpful for restoration practitioners to improve their potential use in current and future restoration programs in the Australian monsoonal tropics.

Enhancing nutrient recovery from food waste anaerobic digestate

The study synthesised the raw liquid fraction of digestate into a nutrient rich solid digestate through acidification whilst preventing nitrogen loss through ammonium volatilisation during evaporation. To stabilise ammonium in the digestate, it was acidified with sulphuric, nitric, and phosphoric acid to produce solid digestate with ammonium sulphate, ammonium nitrate and ammonium phosphate, respectively. These treatments were compared against urea ammonium nitrate, raw digestate, and unacidified solid digestate. To evaluate the effect of these transformed digestate products in soil, a plant growth experiment (Kikuyu; Cenchrus clandestinus) was conducted, and characterised, plant growth, soil chemistry, and rhizosphere bacterial communities. Plant growth was enhanced by all digestate treatments compared to control and urea ammonium nitrate. Ammonium phosphate solid digestate plant growth was significantly higher than all other acidified treatments due to the high P content. Moreover, digestate-amended soil had elevated Proteobacteria and putative denitrification genes.

Life cycle assessment of sludge anaerobic digestion combined with land application treatment route: Greenhouse gas emission and reduction potential

Sewage sludge treatment and disposal is essential for water environment protection and pollution management. Coupling anaerobic digestion with land application offers a promising solution to recycle energy and resources to reduce greenhouse gas(GHG) emissions. However, the comprehensive assessment of the anaerobic digestion treatment route on GHG emissions and reduction potential is lacking. This study used life cycle assessment(LCA) to evaluate the GHG emissions based on two cases. The GHG emissions resulting from the digested sludge land application was considered, and the reduction potentials resulting from biogas utilization and substituting chemical fertilizers were also analyzed. The results showed the net GHG emissions of the two cases were 178.92 and − 26.33 kg CO2-eq/tDS, respectively. When excluding the reduction, the GHG emissions of the two cases were 519.32 and 352.97 kg CO2-eq/tDS, respectively, where the dewatering, digested sludge drying, and land application were the main contributors. The GHG emissions associated with the digested sludge land application accounted for 28% and 45% of the total GHG emissions in two cases, respectively. The GHG emission reduction could be achieved by sludge substitution for chemical fertilizer, which could offset 65.5% and 107.5% of the total GHG emissions in two cases, respectively. While the biogas utilization could only offset less than 10% of the total GHG emissions of both cases. Likewise, improving organic content or specific biogas yield rates could only offset up to 26.2% and 40.3% of the total GHG emissions. These findings provide understanding into evaluating GHG emissions of the sludge anaerobic digestion treatment route.

Nitrogen and phosphorus recovery from cow digestate by struvite precipitation: Process optimization to maximize phosphorus recovery

The combination of the anaerobic digestion of waste biomass (e.g., livestock manure, energy crops and organic wastes) and the digestate treatment allows green energy to be obtained (starting from biogas/biomethane) and nutrients to be returned to the soil, satisfying the principles of the circular economy. Digestate has valuable potential as an organic fertilizer and soil amendment, as it can be an important source of nutrients, nitrogen and phosphorus (N and P), essential for crop growth. However, digestate production sometimes exceeds the capacity of nearby lands to use the nutrients. Therefore, the recovery of nutrients from digestate has become an important task for anaerobic digestion plants, to meet current regulations. In this study, a method combining struvite precipitation and ammonia stripping was tested in the laboratory to better understand the nutrient removal/recovery efficiency of the two nutrients. Results indicate that more than 60% of total P was removed as struvite, which can be used in N–P fertilizer, substituting synthetic mineral fertilizers.The recovery of N and P from digestate by struvite crystallization allows the removal of nutrient excess at farm level, reducing the environmental impacts of using slurry/digestate in agriculture. The recovery of struvite allows the production of a fertilizer that can be easily exported from farms, promoting the circular economy.

Formation of RRR-α-tocopherol in rumen and intestinal digestibility of tocopherols in dairy cows

Tocopherol sources in diets are often a combination of all-rac-α-tocopheryl acetate (synthetic α-tocopherol) from vitamin supplements and natural tocopherols and 2R-(4′R, 8′R)-5,7,8-trimethyltocotrienol (α-tocotrienols) from the feed sources. Synthetic α-tocopherol consists of 8 different stereoisomers including 2R-(4′R, 8′R)-5,7,8-trimethyltocol (RRR-α-tocopherol), 2R-(4′S, 8′R)-5,7,8-trimethyltocol (RSR-α-tocopherol), 2R-(4′R, 8′S)-5,7,8-trimethyltocol (RRS-α-tocopherol), 2R-(4′S, 8′S)-5,7,8-trimethyltocol (RSS-α-tocopherol), 2S-(4′S, 8′S)-5,7,8-trimethyltocol (SSS-α-tocopherol), 2S-(4′R, 8′S)-5,7,8-trimethyltocol (SRS-α-tocopherol), 2S-(4′S, 8′R)-5,7,8-trimethyltocol (SSR-α-tocopherol), and 2S-(4′R, 8′R)-5,7,8-trimethyltocol (SRR-α-tocopherol). The pre-absorption metabolism of tocopherols and tocotrienols in ruminants differs from monogastric animals due to the extensive microbial fermentation in the anaerobic rumen. The current study investigated the impact of toasting and decortication of oats on metabolism in the digestive tract (synthesis, digestion), and intestinal digestibility of tocopherols in dairy cows by using 4 ruminal and intestinal cannulated Danish Holstein cows in a 4 × 4 Latin square design for 4 periods. Cows were fed a total mixed ration ad libitum containing different forms of oats: whole oat, decorticated oat, toasted oat, and decorticated toasted oat, all rolled before mixed ration. Overall means across 4 treatments were statistically analyzed, testing whether overall means were different from zero. Decortication or toasting did not affect the balance or digestibility of α-tocopherols in rumen. Average across treatments showed the ruminal degradation of synthetic α-tocopherol (279 mg/d, P = 0.02; P-value shows that average across treatments is different from zero), synthetic 2R-α-tocopherol (133 mg/d, P < 0.01; summation of RRS-, RSR- and RSS-α-tocopherol), and 2S-α-tocopherol (190 mg/d; P < 0.01, summation of SSS-, SRS-, SSR, and SRR-α-tocopherol), while RRR-α-tocopherol was formed in the rumen (221 mg/d, P = 0.10). The average across treatments showed that small intestinal digestibility of tocopherols ranked in the following order: α-tocotrienol > natural α-tocopherol > synthetic α-tocopherols > 2R-(4′R, 8′R)-,7,8-dimethyltocol (γ-tocopherol). The average across treatments for small intestinal and feed-ileum digestibility ranked in the following order: RRR-α-tocopherol > synthetic 2R-α-tocopherol > 2S-α-tocopherol. Results showed the first evidence for RRR-α-tocopherol formation under anaerobic conditions in the rumen. In addition, synthetic α-tocopherol stereoisomers, γ-tocopherol and α-tocotrienol were degraded in the rumen. There was a discrimination against absorption of synthetic 2R- and 2S-α-tocopherol in the small intestine.

An extracellular polysaccharide is involved in the aluminum tolerance of Pullulanibacillus sp. CA42, a newly isolated strain from the Chinese water chestnut growing in an actual acid sulfate soil area in Vietnam.

A novel aluminum-tolerant bacterial strain CA42 was isolated from the aquatic plant Eleocharis dulcis, which grows in a highly acidic swamp in Vietnam. Inoculation with CA42 allowed Oryza sativa to grow in the presence of 300 μM AlCl3 at pH 3.5, and biofilms were observed around the roots. Using 16S rRNA gene sequencing analysis, the strain was identified as Pullulanibacillus sp. CA42. This strain secreted large amounts of an extracellular polysaccharide (CA42 EPS). Results from structural analyses on CA42 EPS, namely methylation analysis and nuclear magnetic resonance (NMR), indicated that the chemical structure of CA42 EPS was a glycogen-like α-glucan. Purified CA42 EPS and the commercially available oyster glycogen adsorbed aluminum ions up to 15-30 μmol/g dry weight. Digestion treatments with α-amylase and pullulanase completely attenuated the aluminum ion-adsorbing activity of purified CA42 EPS and oyster glycogen, suggesting that the glycogen-like structure adsorbed aluminum ions and that its branching structure played an important role in its aluminum adsorbing activity. Furthermore, the aluminum tolerance of CA42 cells was attenuated by pullulanase treatment directly on the live CA42 cells. These results suggest that CA42 EPS adsorbs aluminum ions and is involved in the aluminum tolerance mechanism of Pullulanibacillus sp. CA42. Thus, this strain may be a potential plant growth-promoting bacterium in acidic soils. In addition, this study is the first to report a glycogen-like polysaccharide that adsorbs aluminum ions.

Earthworm (Perionyx excavatus) Protein Hydrolysate: Hypoglycemic Activity and Its Stability for the Hydrolysate and Its Peptide Fractions

This study aims at exploring earthworm protein hydrolysate and its peptide fractions as a potential hypoglycemic agent by inhibiting α-amylase and α-glucosidase. Firstly, the best hydrolysis conditions to gain the hydrolysates with the highest α-amylase inhibitory activity (α-AIA) and α-glucosidase inhibitory activity (α-GIA) were figured out using a one-factor test. Next, the stability of the hypoglycemic activity of the hydrolysates and their 5 peptide fractions recovered using ultrafiltration membranes were assessed by employing the tests of in vitro digestion, thermal, and pH treatment. The results showed that at the best hydrolysis conditions, the hydrolysates exhibited α-AIA of 91.30 ± 2.51% and α-GIA of 44.69 ± 0.47%. Specifically, the &lt;1 kDa peptide fraction from the hydrolysate expressed a greater α-AIA than that of acarbose, with nearly the same α-GIA as that of voglibose. The α-AIA and α-GIA of the hydrolysates and their fractions were enhanced after the in vitro digestion treatment, whereas they remained over 40% after the pH treatment in the range of 1 to 11 or heat treatment at 100 °C for 180 min. These data provide the preliminary evidence to develop the earthworm protein hydrolysate and its peptide fractions in functional food or nutraceutical products with hypoglycemic activity.

Applying membrane separation technology for integrating high strength cow manure digestate treatment and microalgae cultivation in an open reactor system

Applying membrane separation technology for integrating high strength cow manure digestate treatment and microalgae cultivation in an open reactor system

Impact of organic fertilization by the digestate from by-product on growth, yield and fruit quality of tomato (Solanum lycopersicon) and soil properties under greenhouse and field conditions

BackgroundThe application of organic fertilizer is a sustainable approach to maintain soil fertility in agricultural crop production. In contrast to other organic fertilizers, the digestate from by-products of anaerobic digestion has not been well characterized in terms of its agronomic properties. In this study, different fertilization treatments were investigated to evaluate their impacts on growth, yield and fruit quality of tomatoes and on soil properties under greenhouse and field conditions. The experiments comprised a control (unfertilized) and three treatments with the same nitrogen dose: chemical fertilizer, digestate from by-product (organic fertilizer) and digestate combined with chemical fertilizer.ResultsThe results showed that the application of digestate significantly increased the growth and fruit quality of tomato including height, stem diameter, leaf chlorophyll content index, and photosynthetic rate of tomato plant and sugar–acid ratio, protein content, and ascorbic acid content of the fruit. The nitrate contents in tomato fruit were lower in the digestate treatment and digestate combined with chemical fertilizer treatment than in the chemical fertilizer. The digestate combined with chemical fertilization resulted in the greatest increase in tomato yield, up to 26.29% and 10.78% higher than that in the chemical fertilizer treatment under field and greenhouse conditions, respectively. Moreover, fertilization with digestate treatment and digestate combined with chemical fertilizer treatment increased soil fertility, including soil nitrogen and carbon contents, and enhanced soil enzyme activities under both field and greenhouse conditions. In addition, the growth, yield, and fruit quality of tomato were significantly correlated with soil chemical characteristics and soil enzyme activities.ConclusionsThe effects of digestate treatments to maintain a stable tomato yield and improve fruit quality may be due to the enhanced soil enzymatic activities and chemical properties. These results suggest that the use of digestate as a full or partial replacement for chemical fertilizer could improve the growth and fruit quality of tomato, maintain the yield, and reduce the use of inorganic fertilizers in tomato production.Graphical

Valorization of livestock waste through combined anaerobic digestion and microalgae-based treatment in México: A techno-economic analysis for distributed biogas generation, animal feed production, and carbon credits trading

A large percentage of world’s eutrophication is attributed to the livestock industry, which is responsible for producing over 14% of the global anthropogenic greenhouse gasses emissions (GHG). In Mexico, very few livestock producers have the necessary infrastructure to treat their livestock waste (LW) and most fail to comply with environmental regulations. The treatment of LW through a circular bioeconomy approach can mitigate these negative environmental impacts, while simultaneously producing value-added products. The present work aimed to characterize the spatial variation of the LW generated in cattle, swine, and poultry farms in Jalisco, México. Total nitrogen (TN), phosphorus (TP), and organic matter released from these production units were estimated, along with the associated GHG, considering the standard practice of uncontrolled release. An alternative management scenario using anaerobic digestion (AD) combined with microalgae-based wastewater treatment (MbWT) was evaluated by developing a software-based techno-economic analysis, showing that a centralized LW treatment system could represent a feasible solution to comply the legislation while generating high-protein biomass for animal feed. Besides, the reduction in GHG represents an opportunity for carbon credits trading in voluntary markets for livestock producers in México. Insights are provided regarding the economical, technical, and sociocultural challenges that must be overcome to transition towards more sustainable livestock production practices in Jalisco, México, and other developing regions around the globe.

Effects of operational processes and equipment in palm oil mills on characteristics of raw Palm Oil Mill Effluent (POME): A comparative study of four mills

The characteristics of Palm Oil Mill Effluent (POME) is a crucial factor affecting the yield and quality of biogas produced from anaerobic digestion. Hence, it is essential to understand how the operational processes and equipment in palm oil mills can affect POME characteristics and subsequently, biogas production efficiency. This study aims to evaluate the effects of different operating systems in four Palm Oil Mills (POM), including the usage of three-phase decanters, sludge separators, sludge recirculation, empty fruit bunch (EFB) press, water consumption, and sterilization systems, on POME characteristics such as chemical oxygen demand (COD), biological oxygen demand (BOD), total solids (TS), suspended solids (SS), pH, and oil and grease (OG). Experimental data was collected over a two-year period (from July 2019 to June 2021) at four POMs in Malaysia (A, B, C, and D). The ANOVA analysis showed that differences in the operational process flow and equipment led to significant variations in POME characteristics among the four mills. POM A was the only mill equipped with a three-phase decanter, which reduced the TS concentration in POME and recorded the lowest TS content (25,580 mg/L) compared to POM B, C, and D. However, the COD of POM A was still high due to the continuous addition of effluent from the empty fruit bunch (EFB) press station. POM B used a conventional cages system (CCS) for sterilization, whereas other POMs adopted a continuous sterilization (CS) system. POM B and D had the highest COD (more than 80,000 mg/L) due to low water consumption, absence of decanter, and direct discharge of sterilizer condensate to the sludge pit. POM C has achieved considerably lower TS content (29,144 mg/L) and the lowest COD level of 59,576 mg/L due to the highest water consumption. The hydrocyclone effluent from the kernel crushing plant (KCP) further diluted the POME in POM C. It is recommended to use sludge separators (instead of the three-phase decanter) and continuous sterilization system to produce desirable POME characteristics for maximum biogas generation. The water: FFB ratio should be kept below 1.2 m3/TFFB to maintain moderate COD, BOD, and TS content. This study provides essential information for POME biogas plant developers and POM owners to understand the mill process background and predict the POME qualities before designing an anaerobic digester or effluent treatment ponds.

Exposure and Reactions to Cancer Treatment Misinformation and Advice: Survey Study.

Cancer treatment misinformation, or false claims about alternative cures, often spreads faster and farther than true information on social media. Cancer treatment misinformation can harm the psychosocial and physical health of individuals with cancer and their cancer care networks by causing distress and encouraging people to abandon support, potentially leading to deviations from evidence-based care. There is a pressing need to understand how cancer treatment misinformation is shared and uncover ways to reduce misinformation. We aimed to better understand exposure and reactions to cancer treatment misinformation, including the willingness of study participants to prosocially intervene and their intentions to share Instagram posts with cancer treatment misinformation. We conducted a survey on cancer treatment misinformation among US adults in December 2021. Participants reported their exposure and reactions to cancer treatment misinformation generally (saw or heard, source, type of advice, and curiosity) and specifically on social media (platform, believability). Participants were then randomly assigned to view 1 of 3 cancer treatment misinformation posts or an information post and asked to report their willingness to prosocially intervene and their intentions to share. Among US adult participants (N=603; mean age 46, SD 18.83 years), including those with cancer and cancer caregivers, almost 1 in 4 (142/603, 23.5%) received advice about alternative ways to treat or cure cancer. Advice was primarily shared through family (39.4%) and friends (37.3%) for digestive (30.3%) and natural (14.1%) alternative cancer treatments, which generated curiosity among most recipients (106/142, 74.6%). More than half of participants (337/603, 55.9%) saw any cancer treatment misinformation on social media, with significantly higher exposure for those with cancer (53/109, 70.6%) than for those without cancer (89/494, 52.6%; P<.001). Participants saw cancer misinformation on Facebook (39.8%), YouTube (27%), Instagram (22.1%), and TikTok (14.1%), among other platforms. Participants (429/603, 71.1%) thought cancer treatment misinformation was true, at least sometimes, on social media. More than half (357/603, 59.2%) were likely to share any cancer misinformation posts shown. Many participants (412/603, 68.3%) were willing to prosocially intervene for any cancer misinformation posts, including flagging the cancer treatment misinformation posts as false (49.7%-51.4%) or reporting them to the platform (48.1%-51.4%). Among the participants, individuals with cancer and those who identified as Black or Hispanic reported greater willingness to intervene to reduce cancer misinformation but also higher intentions to share misinformation. Cancer treatment misinformation reaches US adults through social media, including on widely used platforms for support. Many believe that social media posts about alternative cancer treatment are true at least some of the time. The willingness of US adults, including those with cancer and members of susceptible populations, to prosocially intervene could initiate the necessary community action to reduce cancer treatment misinformation if coupled with strategies to help individuals discern false claims.