Effectiveness of Helicobacter pylori Treatments According to Antibiotic Resistance.

INTRODUCTION: Antibiotic resistance is one of the main factors that determine the efficacy of treatments to eradicate Helicobacter pylori infection. Our aim was to evaluate the effectiveness of first-line and rescue treatments against H. pylori in Europe according to antibiotics resistance. METHODS: Prospective, multicenter, international registry on the management of H. pylori (European Registry on H. pylori Management). All infected and culture-diagnosed adult patients registered in the Spanish Association of Gastroenterology-Research Electronic Data Capture from 2013 to 2021 were included. RESULTS: A total of 2,852 naive patients with culture results were analyzed. Resistance to clarithromycin, metronidazole, and quinolones was 22%, 27%, and 18%, respectively. The most effective treatment, regardless of resistance, were the 3-in-1 single capsule with bismuth, metronidazole, and tetracycline (91%) and the quadruple with bismuth, offering optimal cure rates even in the presence of bacterial resistance to clarithromycin or metronidazole. The concomitant regimen with tinidazole achieved an eradication rate of 99% (90/91) vs 84% (90/107) with metronidazole. Triple schedules, sequential, or concomitant regimen with metronidazole did not achieve optimal results. A total of 1,118 non-naive patients were analyzed. Resistance to clarithromycin, metronidazole, and quinolones was 49%, 41%, and 24%, respectively. The 3-in-1 single capsule (87%) and the triple therapy with levofloxacin (85%) were the only ones that provided encouraging results. DISCUSSION: In regions where the antibiotic resistance rate of H. pylori is high, eradication treatment with the 3-in-1 single capsule, the quadruple with bismuth, and concomitant with tinidazole are the best options in naive patients. In non-naive patients, the 3-in-1 single capsule and the triple therapy with levofloxacin provided encouraging results.

Algae and indigenous bacteria consortium in treatment of shrimp wastewater: A study for resource recovery in sustainable aquaculture system.

Shrimp production facilities produce large quantities of wastewater, which consists of organic and inorganic pollutants. High concentrations of these pollutants in shrimp wastewater cause serious environmental problems and, therefore, a method of treating this wastewater is an important research topic. This study investigated the impact of algae and indigenous bacteria on treating shrimp wastewater. A total of four different microalgae cultures, including Chlorococcum minutus, Porphyridum cruentum, Chlorella vulgaris and Chlorella reinhardtii along with two cyanobacterial cultures, Microcystis aeruginosa and Fishcherella muscicola were used with indigenous bacterial cultures to treat shrimp wastewater. The highest soluble chemical oxygen demand (sCOD) removal rate (95%) was observed in the samples that were incubated using F. muscicola. Total dissolved nitrogen was degraded >90% in the C. vulgaris, M. aeruginosa, and C. reinhardtii seeded samples. Dissolved organic nitrogen removal was significantly higher for C. vulgaris (93%) as compared to other treatments. Similarly, phosphate degradation was very successful for all the algae-bacteria consortium (>99%). Moreover, the degradation kinetics were calculated, and the lowest half-life (t1/2) for sCOD (5 days) was recorded for the samples seeded with M. aeruginosa. Similarly, treatment with F. muscicola and C. reinhardtii showed the lowest t1/2 of NH3-N (2.9 days) and phosphate (2.7 days) values. Overall, the results from this study suggest that the symbiotic relationship between indigenous bacteria and algae significantly enhanced the process of shrimp wastewater treatment within 21 days of incubation. The outcome of this study supports resource recovery in the aquaculture sector and could be beneficial to treat a large-scale shrimp facility's wastewater worldwide.

Antibiotic ciprofloxacin removal from aqueous solutions by electrochemically activated persulfate process: Optimization, degradation pathways, and toxicology assessment.

Ciprofloxacin (CIP) is a commonly used antibiotic in the fluoroquinolone group and is widely used in medical and veterinary medicine disciplines to treat bacterial infections. When CIP is discharged into the sewage system, it cannot be removed by a conventional wastewater treatment plant because of its recalcitrant characteristics. In this study, boron-doped diamond anode and persulfate were used to degrade CIP in an aquatic solution by creating an electrochemically activated persulfate (EAP) process. Iron was added to the system as a coactivator and the process was called EAP+Fe. The effects of independent variables, including pH, Fe2+, persulfate concentration, and electrolysis time on the system were optimized using the response surface methodology. The results showed that the EAP+Fe process removed 94% of CIP under the following optimum conditions: A pH of 3, persulfate/Fe2+ concentration of 0.4 mmol/L, initial CIP concentration 30 mg/L, and electrolysis time of 12.64 min. CIP removal efficiency was increased from 65.10% to 94.35% by adding Fe2+ as a transition metal. CIP degradation products, 7 pathways, and 78 intermediates of CIP were studied, and three of those intermediates (m/z 298, 498, and 505) were reported. The toxicological analysis based on toxicity estimation software results indicated that some degradation products of CIP were toxic to targeted animals, including fathead minnow, Daphnia magna, Tetrahymena pyriformis, and rats. The optimum operation costs were similar in EAP and EAP+Fe processes, approximately 0.54 €/m3.

Developments and application of chitosan-based adsorbents for wastewater treatments.

Water quality is deteriorating continuously as increasing levels of toxic inorganic and organic contaminants mostly discharging into the aquatic environment. Removal of such pollutants from the water system is an emerging research area. During the past few years use of biodegradable and biocompatible natural additives has attracted considerable attention to alleviate pollutants from wastewater. The chitosan and its composites emerged as a promising adsorbents due to their low price, abundance, amino, and hydroxyl groups, as well as their potential to remove various toxins from wastewater. However, a few challenges associated with its practical use include lack of selectivity, low mechanical strength, and solubility in acidic medium. Therefore, several approaches for modification have been explored to improve the physicochemical properties of chitosan for wastewater treatment. Chitosan nanocomposites found effective for the removal of metals, pharmaceuticals, pesticides, microplastics from the wastewaters. Nanoparticle doped with chitosan in the form of nano-biocomposites has recently gained much attention and proven a successful tool for water purification. Hence, applying chitosan-based adsorbents with numerous modifications is a cutting-edge approach to eliminating toxic pollutants from aquatic systems with the global aim of making potable water available worldwide. This review presents an overview of distinct materials and methods for developing novel chitosan-based nanocomposites for wastewater treatment.

Esterase and ALDH dehydrogenase-based pesticide degradation by Bacillus brevis 1B from a contaminated environment.

The isolated bacterial strain (Bacillus brevis strain 1 B) showed a maximum tolerated level of 450 mg L-1 of the selected pesticides namely: imidacloprid, fipronil, cypermethrin, and sulfosulfuron. Within 15 days of the experiment, strain 1 B was able to reduce up to 95% of a pesticide mixture (20 mg L-1) in a carbon-deficient medium (minimal medium). The optimal conditions obtained using Response Surface Methodology (RSM) were: inoculums; 2.0 × 107 CFU mL-1, shaking speed; 120 rpm, and pesticide concentration; 80 mg L-1. After 15 days of soil-based bioremediation using strain 1 B, the degradation pattern for imidacloprid, fipronil, cypermethrin, sulfosulfuron, and control was 99, 98.5, 94, 91.67, and 7%, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis was used to determine the intermediate metabolites of cypermethrin with bacterial 1 B as 2-cyclopenten-1-one, 2-methylpyrrolidine, 2-oxonanone, 2-pentenoic acid, 2-penten-1-ol, hexadecanoic acid or palmitic acid, pentadecanoic acid, 3-cyclopentylpropionic acid, and 2-dimethyl. Furthermore, genes encoding aldehyde dehydrogenase (ALDH) and esterase were expressed under stress conditions and connected to pesticide bioremediation. Hence the efficacy of Bacillus brevis (1 B) could be employed for the bioremediation of pesticide mixtures and other toxic substances (dye, polyaromatic hydrocarbon, etc.) from contaminated sites.

Cyanophage-cyanobacterial interactions for sustainable aquatic environment.

Cyanobacteria are a type of bloom-forming phytoplankton that cause environmental problems in aquatic ecosystems worldwide. Cyanobacterial harmful algal blooms (cyanoHAB) often produce cyanotoxins that affect public health by contaminating surface waters and drinking water reservoirs. Conventional drinking water treatment plants are ineffective in treating cyanotoxins, even though some treatment methods are available. Therefore, innovative and advanced treatment methods are required to control cyanoHABs and their cyanotoxins. The goal of this review paper is to provide insight into the use of cyanophages as an effective form of biological control method for the removal of cyanoHABs in aquatic systems. Moreover, the review contains information on cyanobacterial blooms, cyanophage-cyanobacteria interactions, including infection mechanisms, as well as examples of different types of cyanobacteria and cyanophages. Moreover, the real-life application of cyanophages in marine and freshwater environments and the mode of action of cyanophages were compiled.

An integration of algae-mediated wastewater treatment and resource recovery through anaerobic digestion.

Eutrophication is one of the major emerging challenges in aquatic environment. Industrial facilities, including food, textile, leather, and paper, generate a significant amount of wastewater during their manufacturing process. Discharge of nutrient-rich industrial effluent into aquatic systems causes eutrophication, eventually disturbs the aquatic system. On the other hand, algae provide a sustainable approach to treat wastewater, while the resultant biomass may be used to produce biofuel and other valuable products such as biofertilizers. This review aims to provide new insight into the application of algal bloom biomass for biogas and biofertilizer production. The literature review suggests that algae can treat all types of wastewater (high strength, low strength, and industrial). However, algal growth and remediation potential mainly depend on growth media composition and operation conditions such as light intensity, wavelength, light/dark cycle, temperature, pH, and mixing. Further, the open pond raceways are cost-effective compared to closed photobioreactors, thus commercially applied for biomass generation. Additionally, converting wastewater-grown algal biomass into methane-rich biogas through anaerobic digestion seems appealing. Environmental factors such as substrate, inoculum-to-substrate ratio, pH, temperature, organic loading rate, hydraulic retention time, and carbon/nitrogen ratio significantly impact the anaerobic digestion process and biogas production. Overall, further pilot-scale studies are required to warrant the real-world applicability of the closed-loop phycoremediation coupled biofuel production technology.

Hyperspectral Image Data and Waveband Indexing Methods to Estimate Nutrient Concentration on Lettuce (Lactuca sativa L.) Cultivars.

Lettuce is an important vegetable in the human diet and is commonly consumed for salad. It is a source of vitamin A, which plays a vital role in human health. Improvements in lettuce production will be needed to ensure a stable and economically available supply in the future. The influence of nitrogen (N), phosphorus (P), and potassium (K) compounds on the growth dynamics of four hydroponically grown lettuce (Lactuca sativa L.) cultivars (Black Seeded Simpson, Parris Island, Rex RZ, and Tacitus) in tubs and in a nutrient film technique (NFT) system were studied. Hyperspectral images (HSI) were captured at plant harvest. Models developed from the HSI data were used to estimate nutrient levels of leaf tissues by employing principal component analysis (PCA), partial least squares regression (PLSR), multivariate regression, and variable importance projection (VIP) methods. The optimal wavebands were found in six regions, including 390.57-438.02, 497-550, 551-600, 681.34-774, 802-821, and 822-838 nm for tub-grown lettuces and four regions, namely 390.57-438.02, 497-550, 551-600, and 681.34-774 nm for NFT-system-grown lettuces. These fitted models' levels showed high accuracy (R2=0.85-0.99) in estimating the growth dynamics of the studied lettuce cultivars in terms of nutrient content. HSI data of the lettuce leaves and applied N solutions demonstrated a direct positive correlation with an accuracy of 0.82-0.99 for blue and green regions in 400-575 nm wavebands. The results proved that, in most of the tested multivariate regression models, HSI data of freshly cut leaves correlated well with laboratory-measured data.

Performance of indirect immunofluorescence test and immunoblot tests in the evaluation of antinuclear and antimitochondrial antibodies.

BACKGROUND: Antinuclear antibodies (ANA) and antimitochondrial antibodies (AMA) have essential markers for the diagnosis of autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC). These autoantibodies are detecting different laboratory methods. In this study, we studied the diagnostic performance of used methods in detecting ANA and AMA. METHODS: The autoantibody profiles of patients with AIH and PBC groups were analyzed with the indirect immunofluorescence test (IIF) and liver-specific antigens containing immunoblot test (IB). RESULTS: There were 45 (87%) women in the study group and 8 (53%) women in the control group. The mean age of the patients was 50.5 ± 14.21 years old. The serum ALT and AST levels were higher in AIH, and ALP, GGT, and Ig M were higher in PBC. IIF test results among AIH/PBC groups; there was no difference in overall ANA positivity (p: 0.078). AMA was negative in all patients with AIH but positive in 83.3% of patients with PBC. IB test results among AIH/PBC groups; antibodies against PDGH, LKM-1, and Scl-70 were not observed in any patient with AIH/PBC. Except for M2 (p: 0.001) and M23E (p: 0.007) antibodies, there was no significant difference in antibodies between groups. Out of five PBC patients with negative AMA by IIF method, one was positive for AMA-M2, two were positive anti-gp210, and three were positive anti-M2-3E, but anti-sp100 was negative in all of them by the IB. DISCUSSION: AIH/PBC has complex associations with different autoantibodies, and some of these antibodies are not readily detected by the IIF test. IB assays with a wide variety of liver-specific antigens may be helpful in the diagnosis (especially in patients with AMA negative PBC) and follow-up in AIH/PBC patients.

European Registry on Helicobacter pylori management (Hp-EuReg): patterns and trends in first-line empirical eradication prescription and outcomes of 5 years and 21 533 patients.

OBJECTIVE: The best approach for Helicobacter pylori management remains unclear. An audit process is essential to ensure clinical practice is aligned with best standards of care. DESIGN: International multicentre prospective non-interventional registry starting in 2013 aimed to evaluate the decisions and outcomes in H. pylori management by European gastroenterologists. Patients were registered in an e-CRF by AEG-REDCap. Variables included demographics, previous eradication attempts, prescribed treatment, adverse events and outcomes. Data monitoring was performed to ensure data quality. Time-trend and geographical analyses were performed. RESULTS: 30 394 patients from 27 European countries were evaluated and 21 533 (78%) first-line empirical H. pylori treatments were included for analysis. Pretreatment resistance rates were 23% to clarithromycin, 32% to metronidazole and 13% to both. Triple therapy with amoxicillin and clarithromycin was most commonly prescribed (39%), achieving 81.5% modified intention-to-treat eradication rate. Over 90% eradication was obtained only with 10-day bismuth quadruple or 14-day concomitant treatments. Longer treatment duration, higher acid inhibition and compliance were associated with higher eradication rates. Time-trend analysis showed a region-dependent shift in prescriptions including abandoning triple therapies, using higher acid-inhibition and longer treatments, which was associated with an overall effectiveness increase (84%-90%). CONCLUSION: Management of H. pylori infection by European gastroenterologists is heterogeneous, suboptimal and discrepant with current recommendations. Only quadruple therapies lasting at least 10 days are able to achieve over 90% eradication rates. European recommendations are being slowly and heterogeneously incorporated into routine clinical practice, which was associated with a corresponding increase in effectiveness.

Serum levels of inflammatory markers CRP, ESR and albumin in relation to survival for patients with hepatocellular carcinoma.

INTRODUCTION: Hepatocellular carcinoma is associated with several chronic inflammatory conditions. It is increasingly understood that the inflammation may be part of the carcinogenic process and prognostically important. OBJECTIVE: To evaluate the serum levels of three inflammation markers in relation to survival in HCC patients. METHODS: We retrospectively examined the serum levels of CRP, albumin and ESR, both singly and in combination, in relation to patient survival. RESULTS: Survival worsened with increase in CRP or ESR or decrease in albumin levels. Combinations of CRP plus albumin or CRP plus ESR were associated with an even greater range of survival (3-fold), together with significant differences in maximum tumor diameter (PVT) and percent of patients with portal vein thrombosis (PVT). The triplet of CRP plus albumin plus ESR was associated with a sevenfold difference in survival, comparing low vs high parameter levels. These significant differences were found in patients with small or large tumors. CONCLUSIONS: Combinations of CRP with albumin or ESR or all three parameters together significantly related to differences in survival and to differences in MTD and percent PVT, in patients with both small and large size HCCs.

Lack of awareness of Hepatitis B screening and vaccination in high-risk groups

Background/aim: Hepatitis B virus (HBV) vaccination rates are insufficient in high-risk patients worldwide. This study aimed to investigate the screening, immunization, and vaccination rates in three high-risk groups for HBV infection: allogeneic hematopoietic stem cell transplantation (AHSCT), renal transplantation (RT), and chronic hepatitis C (CHC) groups. Materials and methods: The serological data of consecutive patients between 2014 and 2019 were reviewed using the hospital database. Results: The HBV screening rates were 100.0%, 90.4%, and 82.4% in the AHSCT, CHC, and RT groups, respectively (p = 0.003). The immunization rates against HBV through either previous exposure or vaccination were 79.5%, 71.7%, and 46.5% in the AHSCT, RT, and CHC groups, respectively (p < 0.001). The HBV vaccination rate was significantly low in the CHC group (71.5%, 69.0%, 34.6% in the AHSCT, RT, and CHC groups, respectively, p < 0.001). If patients lost their immunity due to immunosuppressive therapy were accounted, the vaccination rates increased to 95.2% in the AHSCT group and 72.9% in the RT group. The rate of annual screening for HBV status was 97.9% in the AHSCT group, but it was only 23.9% in the RT group. Conclusion: HBV screening and vaccination rates were significantly lower in the RT and CHC groups than in the AHSCT group.

C-Reactive Protein and Platelet-Lymphocyte Ratio as Potential Tumor Markers in Low-Alpha-Fetoprotein Hepatocellular Carcinoma.

The hepatocellular carcinoma (HCC) tumor marker alpha-fetoprotein (AFP) is only elevated in about half of the HCC patients, limiting its usefulness in following the effects of therapy or screening. New markers are needed. It has been previously noted that the inflammation markers C-reactive protein (CRP) and platelet-lymphocyte ratio (PLR) are prognostically important and may reflect HCC aggressiveness. We therefore examined these 2 markers in a low-AFP HCC cohort and found that for HCCs > 2 cm, both markers significantly rise with an increasing maximum tumor diameter (MTD). We calculated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and Youden index value for each marker, and their area-under-the-curve values for each MTD group. Patients were dichotomized into 2 groups based on the CRP and PLR from the receiver-operating characteristic curve analysis. In the logistic regression models of the 4 different MTD patient groups, CRP and PLR levels were statistically significant to estimate MTD in univariate logistic regression models of MTD groups > 2 cm. CRP and PLR were then combined, and the combination was statistically significant to estimate MTD groups of 3-, 4-, and 5-cm cutoffs. CRP and PLR thus have potential as tumor markers for low-AFP HCC patients, and possibly for screening.

Characteristics of Hepatocellular Carcinoma Aggressiveness Factors in Turkish Patients.

A large cohort of hepatocellular carcinoma (HCC) patients from several collaborating Turkish institutions were examined for the tumor parameters of maximum diameter (MTD), portal vein thrombosis (PVT), and α-fetoprotein (AFP) levels. A relationship was found between MTD and blood platelet levels. Patients with large ≥5 cm tumors who had normal platelet levels had significantly larger tumors, higher percent of PVT, and significantly lower blood total bilirubin and liver cirrhosis than similar ≥5 cm tumor patients having thrombocytopenia. A comparison of patients with and without PVT showed significantly larger tumors, greater multifocality, blood AFP, and C-reactive protein levels, and, interestingly, lower HDL levels in the patients with PVT. Fifty-eight percent of the total cohort had AFP levels ≤100 IU/mL (and 42.1% had values ≤20 IU/mL). These patients had significantly smaller tumors, less tumor multifocality and percent PVT, lower total bilirubin, and less cirrhosis. There was considerable geographic heterogeneity within Turkey in the patterns of HCC presentation, with areas of higher and lower hepatitis B virus, hepatitis D virus, cirrhosis, and tumor aggressiveness parameters. Turkish patients thus have distinct patterns of presentation, but the biological relationships between MTD and both platelets and bilirubin levels are similar to the relationships that have been reported in other ethnic patient groups.

Impact of operations and cleaning on membrane fouling at a wastewater reclamation facility.

Effects of operational changes on membrane fouling were evaluated for a wastewater reclamation facility. The focuses were on addition of a coagulant (ferric chloride) versus no addition and an accidental high chlorine (sodium hypochlorite) dose. Two membrane modules with different service ages, 3 years versus 9 months, were compared. Fouling rates ranged between 2 and 3 times higher during no ferric chloride addition. Chemical cleaning frequency was reduced by approximately 5 times during ferric chloride addition for older membranes, while it did not change for newer membranes. High chlorine dose had slightly improved membrane permeability for newer membrane, and reduced the transmembrane pressure (TMP) for both older and newer membranes. Chemical wash with enzymatic detergents substantially improved membrane permeability and reduced TMP for both older and newer membranes. Fouling index values indicated that coagulant addition had greater impact on performance recovery for older membranes than newer membranes. Successful and economical operation of membranes depends on fouling rate, which in this study was found to be a function of flux, membrane age, pretreatment, and cleaning type and frequency.

Bioavailability of wastewater derived dissolved organic nitrogen to green microalgae Selenastrum capricornutum, Chlamydomonas reinhardtii, and Chlorella vulgaris with/without presence of bacteria.

Effluent dissolved organic nitrogen (DON) is problematic in nutrient sensitive surface waters and needs to be reduced to meet demanding total dissolved nitrogen discharge limits. Bioavailable DON (ABDON) is a portion of DON utilized by algae or algae+bacteria, while biodegradable DON (BDON) is a portion of DON decomposable by bacteria. ABDON and BDON in a two-stage trickling filter (TF) wastewater treatment plant was evaluated using three different microalgal species, Selenastrum capricornutum, Chlamydomonas reinhardtii and Chlorella vulgaris and mixed cultured bacteria. Results showed that up to 80% of DON was bioavailable to algae or algae+bacteria inoculum while up to 60% of DON was biodegradable in all the samples. Results showed that C. reinhardtii and C. vulgaris can be used as a test species the same as S. capricornutum since there were no significant differences among these three algae species based on their ability to remove nitrogen species.

Removal of aqueous cyanide with strongly basic ion-exchange resin.

The removal of cyanide (CN-) from aqueous solutions using a strongly basic ion-exchange resin, Purolite A-250, was investigated. The effects of contact time, initial CN- concentration, pH, temperature, resin dosage, agitation speed, and particle size distribution on the removal of CN- were examined. The adsorption equilibrium data fitted the Langmuir isotherm very well. The maximum CN- adsorption capacity of Purolite A-250 was found to be 44 mg CN- g(-1) resin. More than 90% CN- adsorption was achieved for most CN- solutions (50, 100, and 200 mg CN- L(-1)) with a resin dose of 2 g L(-1). The equilibrium time was ∼20 min, optimum pH was 10.0-10.5, and optimum agitation speed was 150 rpm. An increase in adsorption of CN- with increasing resin dosage was observed. Adsorption of CN- by the resin was marginally affected (maximum 4% variation) within an environmentally relevant temperature range of 20-50 °C. Fixed-bed column (20.5 mm internal diameters) experiments were performed to investigate the effects of resin bed depth and influent flow rate on breakthrough behaviour. Breakthrough occurred in 5 min for 0.60 cm bed depth while it was 340 min for 5.40 cm bed depth. Adsorption capacity was 25.5 mg CN- g(-1) for 5 mL min(-1) flow rate and 3.9 mg CN- g(-1) for 20 mL min(-1) flow rate. The research has established that the resin can be effectively used for CN- removal from aqueous solutions.

Modeling Environmental Conditions in Poultry Production: Computational Fluid Dynamics Approach.

In recent years, computational fluid dynamics (CFD) has become increasingly important and has proven to be an effective method for assessing environmental conditions in poultry houses. CFD offers simplicity, efficiency, and rapidity in assessing and optimizing poultry house environments, thereby fueling greater interest in its application. This article aims to facilitate researchers in their search for relevant CFD studies in poultry housing environmental conditions by providing an in-depth review of the latest advancements in this field. It has been found that CFD has been widely employed to study and analyze various aspects of poultry house ventilation and air quality under the following five main headings: inlet and fan configuration, ventilation system design, air temperature-humidity distribution, airflow distribution, and particle matter and gas emission. The most commonly used turbulence models in poultry buildings are the standard k-ε, renormalization group (RNG) k-ε, and realizable k-ε models. Additionally, this article presents key solutions with a summary and visualization of fundamental approaches employed in addressing path planning problems within the CFD process. Furthermore, potential challenges, such as data acquisition, validation, computational resource requirements, meshing, and the selection of a proper turbulence model, are discussed, and avenues for future research (the integration of machine learning, building information modeling, and feedback control systems with CFD) are explored.

Life cycle assessment on environmental feasibility of microalgae-based wastewater treatment for shrimp recirculating aquaculture systems.

This life cycle assessment (LCA) study analyzed the environmental consequences of integrating microalgae-based wastewater treatment into a shrimp farm with recirculating aquaculture systems (RAS). Microalgae treatment produced <10 % of the system's freshwater eutrophication potential (FEP), marine eutrophication potential (MEP) and global warming potential, which was dominantly contributed by electricity use. Microalgae treatment performed comparably to activated sludge treatment for FEP reduction, and was more effective in remediating marine eutrophication. Replacing coal in electricity mix, particularly with renewables, reduced the system's impacts by up to 90-99 %. Performing the LCA based on system expansion generally obtained higher impacts compared to allocation. Utilizing algal biomass for biogas production reduced the MEP; however, production of feed ingredient and biodiesel were not environmentally beneficial. This study proved the use of microalgae for aquaculture wastewater treatment to be environmentally feasible, the results can guide more sustainable RAS operations and design of full-scale microalgae treatment.

Biodegradability and bioavailability of dissolved substances in aquaculture effluent: Performance of indigenous bacteria, cyanobacteria, and green microalgae.

Aquaculture is a controlled aquatic farming sector and one of the most important human food sources. Fish farming is one of the predominant, fast-growing sectors that supply seafood products worldwide. Along with its benefits, aquaculture practices can discharge large quantities of nutrients into the environment through non-treated or poorly treated wastewater. This study aims to understand the nutrient composition of fish wastewater and the use of indigenous bacteria, cyanobacteria, and microalgae as an alternative biological treatment method. Wastewater samples from a local fish farming facility were collected and treated using six different species of cyanobacteria and microalgae include Chroococcus minutus, Porphyridium cruentum, Chlorella vulgaris, Microcystis aeruginosa, Chlamydomonas reinhardtii, and Fischerella muscicola. All the samples were incubated for 21 days, and the following parameters were measured weekly: Chemical oxygen demand (COD), phosphate, total dissolved nitrogen, and dissolved inorganic nitrogen. In addition, dissolved organic nitrogen (DON), bioavailable DON (ABDON), and biodegradable DON (BDON) were calculated from the mass-balance equations. Colorimetric and digestive methods were used for the parameter measurements. The results showed that C. reinhardtii reduced the soluble COD concentration by 74.6 %, DON by 94.3 %, and phosphorous by more than 99 %. Moreover, M. aeruginosa, and C. minutus significantly reduced inorganic nitrogen species (>99 %). This alternative fish wastewater treatment method was explored to gain insight into fish wastewater nutrient composition and to create a sustainable alternative to conventional fish wastewater treatment methods.