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Effluent from palm oil mills is one of the main sources of pollution that seriously affects the physicochemical parameters in water bodies. Palm oil mill effluent (POME) is a potential hazard to the general environment. Regularly monitoring effluent is important to ensure industry compliance with effluent quality limits based on national and international regulations to safeguard human life, aquatic organisms, and other living organisms. This research focused on analyzing the physicochemical parameters of wastewater palm oil mill secondary effluent (POMSE) from palm oil mills in Rokan Hulu, Riau. The assessed physicochemical parameters included pH, chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS), total nitrogen, oil and fat, turbidity, and odor. The results indicated significant differences in characteristics in some of the observed parameters. Our findings were: pH (6.03−8.42); BOD (36.7−2,136.0 mg/L); COD (26.33−4,753.00 mg/L); TSS (30-5,438 mg/L); total nitrogen (361-830 mg/L); oil and fat (4−23 mg/L). The physicochemical characteristics of the effluent in the last treatment pond before being discharged through the liquid waste sewage have met the wastewater standards of the palm oil industry.

Microplastic degradation by bacteria can degrade low-density polyethylene (LDPE). This study aimed to analyze the potential of Ambon Bay bacteria for microplastic degradation, the condition of microplastics after degradation, and identification of the potential for microplastic degradation. The results of isolation revealed as many as 20 bacterial isolates, which correlated with physicochemical conditions in the waters of Ambon Bay. Nine of them could degrade microplastics as indicated by the presence of a clear zone, namely KA1, KA2, KA3, KA4, KA5, KA9, KA10, KS6, and KS8. They were checked for biofilm formation, microplastic hydrophobicity, and percentage of microplastic weight reduction. Four isolates with the highest percentage of microplastic weight reduction on day 40 were KA1, KA2, KA3, and KA10 at 36.19%, 10.16%, 28.39%, and 17.07%, respectively. The results of LDPE microplastic degradation showed differences using field emission scanning electron microscopy-energy dispersive spectroscopy (FESEM/EDS), attenuated total reflection-fourier transform infrared (ATRFTIR), and X-ray diffraction (XRD). The bacterial isolates identified were KA1 (Bacillus cereus), KA2 (Bacillus toyonesis), KA3 (Bacillus paramycoides), and KA10 (Escherichia coli). Indigenous bacteria from the waters of Ambon Bay have the potential to degrade LDPE microplastics, which causes structural changes, decreased crystallinity, weight, and C=C groups in microplastics after degradation, with bacterial isolate KA1 identified as Bacillus cereus showing the best potential with degradation of LDPE microplastics by 36.19%. [ABSTRACT FROM AUTHOR]

Functional food components are vital for preserving health and avoiding illnesses by supplying necessary nutrients and maintaining physiological equilibrium. Nevertheless, the efficient distribution of these substances is impeded by obstacles such as limited solubility and stability, particularly in the gastrointestinal system. Integrating these elements into hydrogel beads offers a viable approach to improve their absorption. This work investigated the synthesis of hydrogel beads by combining four natural polymers: carboxymethyl cellulose (CMC), alginate, chitosan, and guar gum. The hydrogel was formed by crosslinking aided with calcium chloride. The hydrogels were characterized by swelling tests, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Experiments conducted using simulated gastric and intestinal fluids showed that some formulations are appropriate for delivering nutrients to certain parts of the gastrointestinal tract. The FTIR analysis revealed clear characteristics of each polymer and their combinations in the hydrogel compositions. The hydrogel beads' morphological features were revealed by SEM imaging. This work offers valuable information on how to develop hydrogels as carriers for effectively delivering nutrients into the gastrointestinal system. It also proposes potential areas for further investigation in integrating active substances into hydrogel matrices. [ABSTRACT FROM AUTHOR]

The study proposed identifying the changes in bacterial community and diversity and exploring the potential correlations among sediment parameters and benthic bacterial communities under different mangrove ecosystems rehabilitation statuses. Three sites were investigated, 1. Kampung Blekok (KB) as the long rehabilitation period site; 2. Banyuurip Mangrove Center (BMC) as the short rehabilitation period site; 3. Pulau Lusi (PL) as the reclamation site. The physicochemical parameters and benthic bacteria from the mangrove sediment of the three locations were observed. The data were analyzed statistically to determine the sites' variation and the correlation between parameters. The results found that the physicochemical parameters among restoration sites varied. Soil organic matter (SOM) in long and short rehabilitation period sites was more than 1.5 fold higher than those in the reclamation site. Cation exchange capacity (CEC), calcium and potassium ions, and soil conductivity of the restoration site have higher values and can reach more than 1.3 fold compared to the other sites. According to diversity indices and taxa richness, benthic bacteria in the restoration were the most diverse. Proteobacteria dominated in natural and restoration sites; meanwhile, Firmicutes dominated in the reclamation site. Sulfurovum aggregans was found abundant in the long and short rehabilitation sites; meanwhile, Mesobacillus subterraneus was the dominant species in the reclamation site. Furthermore, the bacterial taxa richness was positively correlated with SOM and the bacterial diversity was correlated with CEC and conductivity. [ABSTRACT FROM AUTHOR]

Farmers in Malang cultivated rice intensively due to water availability, but yields reduced gradually. It might also reduce soil productivity and increase pest attacks. Sorghum is one of the easiest crops to be cultivated, and Leguminosae are known as pioneer cover crops. Therefore, the conversion field to organic polyculture was needed using sorghum and legumes. The research aims were to evaluate soil fauna dynamics and soil properties in the 3, 6, and 12 months after converting (mac) into an organic polyculture. Micro-climate and soil properties were recorded including air temperature (°C), day length (hours), rainfall (mm), soil water content (%), organic matter content (%), electrical conductivity (mS.m-1), pH, and bulk density (g.cm-3). Soil macrofauna was sampled using hand sorting for five plots (20 × 20 × 10 cm) in each field. Identified soil macrofauna was used to determine the density, frequency, Important Value Index (IVI), Shannon Diversity Index (H'), Evenness Index (E), Simpson Dominance Index (D), diversity t-test, and Indicator Value. The Canonical Correspondence Analysis (CCA) was used to analyze the interaction among abiotic properties and macrofauna using PAST 4.05. Results showed that the improvement of soil properties, including soil organic matter and soil macrofauna, was recorded at six mac compared to the intensive rice field, and continuously at 12 mac. The richness, diversity, and evenness of soil macrofauna taxa were higher in the converted field than in the intensive one due to organic polyculture. Moreover, we recorded a better proportion of detritivores and predators in the converted field after 12 months. Based on Indicator Value analysis, the dominant fire ants (Solenopsis sp.) in the intensive rice field might be considered as a potential indicator of unhealthy soil in the intensive rice fields. Whereas in the converted field the dominancy of these ants greatly decreased. We concluded that within six months conversion using the organic polyculture improved soil properties. [ABSTRACT FROM AUTHOR]

In this study, magnetohydrodynamic effects on the mixed convection flow of nanofluid particles, namely, Cu (copper) and [Al.sub.2][O.sub.3] (alumina) near a stagnation region over a vertical plate in the presence of viscous dissipation is investigated. The governing equations of the nanofluid flow model proposed by Tiwari and Das (Int. J. Heat Mass Transfer, 50, 2002 (2007). doi:10.1016/j.ijheatmasstransfer.2006.09.034) are converted into a dimensionless nonlinear system of ordinary differential equations by using the similarity transformation. The solution of the resulting equations is obtained numerically by using a very efficient implicit scheme known as the Keller box method. A comparison with previous studies is shown in tabular form and excellent agreement is found. The effects of pertinent parameters like magnetic parameter M, Eckert number Ec, and volume fraction parameter φ on velocity, temperature, skin friction coefficient, and local Nusselt number with fixed value of Prandtl number Pr = 6.2 are shown graphically and discussed. These results show that the skin friction coefficient increases for both nanoparticles in assisting and opposing flow cases because of increasing absolute values of M and Ec, on the other hand heat transfer rate is enhanced in the opposing flow case and reduced in the assisting flow case. The values of skin friction coefficient for both nanoparticles, namely, Cu and [Al.sub.2][O.sub.3] increase with the increase in volume fraction parameter φ in both assisting and opposing flow cases and Cu has a higher value than [Al.sub.2][O.sub.3]. The same behavior is observed for local Nusselt number in opposing flow, but in assisting flow the value of local Nusselt number decreases with the increase of φ in the presence of magnetic and viscous dissipation effects and Cu has a smaller value than [Al.sub.2][O.sub.3]. PACS Nos.: 47.35.Tv, 47.65.-d, 47.85.Dh, 44.20.+b, 02.60.-X. Nous etudions ici les effets magnetohydrodynamiques sur l'ecoulement de convection mixte d'un nano-fluide a particules de Cu et de [Al.sub.2][O.sub.3], pres d'une region de stagnation sur une plaque verticale avec dissipation visqueuse. Les equations directrices du modele d'ecoulement de nano-fluide propose par Tiwari et Das (Int. J. Heat Mass Transfer, 50, 2002 (2007). doi:10.1016/j.ijheatmasstransfer.2006.09.034) sont converties en un systeme non lineaire sans dimensions d'equations differentielles ordinaires a l'aide d'une transformation de similarite. Les equations resultantes sont solutionnees numeriquement en utilisant la methode de la boite de Keller. Un tableau comparatif montre un excellent accord avec des resultats anterieurs. Nous illustrons graphiquement les effets des parametres pertinents, comme le parametre magnetique M, le nombre de Ecker Ec et le parametre de fraction volumique φ sur la vitesse, la temperature, le coefficient de friction superficielle et le nombre de Nusselt pour un nombre de Prandtl fixe a Pr = 6.2. Les resultats montrent que le coefficient de friction superficielle augmente pour les deux types de nanoparticules et dans les deux cas d'ecoulement assiste et oppose selon la valeur absolue de M et de Ec. D'autre part, le taux de transfert de chaleur augmente dans le cas d'opposition a l'ecoulement et diminue dans le cas d'assistance a l'ecoulement. La valeur du coefficient de friction superficielle pour les deux types de nanoparticules augmente avec l'augmentation de φ dans les deux cas d'assistance et d'opposition a l'ecoulement et sont plus elevees pour le Cu que pour [Al.sub.2][O.sub.3]. Le meme comportement est observe pour le nombre de Nusselt dans le cas d'opposition a l'ecoulement, mais il diminue dans le cas d'ecoulement assiste lorsque φ augmente et en presence d'effets magnetiques et visqueux et ici la valeur pour Cu est plus faible que celle pour [Al.sub.2][O.sub.3]. [Traduit par la Redaction], Introduction The boundary layer stagnation point flow has gained considerable researcher attention in the last decade because of its many applications in industry, including electronic devices cooled by fans, nuclear [...]