A novel encapsulation of 16 polycyclic aromatic hydrocarbons in petroleum sludge with palm oil fuel ash binder; an optimization study and sensitivity analysis using machine learning application.

Palm oil fuel ash (POFA) has limited use as a fertilizer, while contribute effectively to the environmental contamination and health risks. Petroleum sludge poses a serious effect on the ecological environment and human health. The present work aimed to present a novel encapsulation process with POFA binder for treating petroleum sludge. Among 16 polycyclic aromatic hydrocarbons, four compounds were selected for the optimization of encapsulation process due to their high risk as carcinogenic substrates. Percentage PS (10-50%) and curing days (7-28 days) factors were used in the optimization process. The leaching test of PAHs was assessed using a GC-MS. The best operating parameters to minimize PAHs leaching from solidified cubes with OPC and10% POFA were recorded with 10% PS and after 28 days, at which PAH leaching was 4.255 and 0.388 ppm with R2 is 0.90%. Sensitivity analysis of the actual and predicted results for both the control and the test (OPC and 10% POFA) revealed that the actual results of the 10% POFA experiments have a high consistency with the predicted data (R2 0.9881) while R2 in the cement experiments was 0.8009. These differences were explained based on the responses of PAH leaching toward percentage of PS and days of cure. In the OPC encapsulation process, the main role was belonged to PS% (94.22%), while with 10% POFA, PS% contributed by 32.36 and cure day contributed by 66.91%.

Metronidazole photocatalytic degradation by zinc oxide nanoparticles synthesized in watermelon peel extract; Advanced optimization, simulation and numerical models using machine learning applications.

Antibiotics in water systems and wastewater are among the greatest major public health problem and it is global environmental issues. Herein a novel approach for the photocatalytic degradation of metronidazole (MTZ) by using eco-green zinc oxide nanoparticles (EG-ZnO NPs) which biosynthesised using watermelon peels extracts has been investigated. Mathematical prediction models using an adaptive neuro-fuzzy inference system (ANFIS), artificial neural networks (ANN) and response surface methodology (RSM) were used to determine the optimal conditions for the degradation process. The FESEM analysis revealed that EG-ZnO NPs was white with a spherical shape and size between 40 and 88 nm. The simulation process for the mathematical prediction model revealed that the best validation performance was 55.35 recorded at epoch 2, the coefficient (R2) was 0.9967 for training data, as detected using ANN analysis. The best operating parameters for MTZ degradation was predicted using RSM to be: 170 mg L-1 of EG-ZnO NPs, 20.61 mg 100 mL-1 of MTZ, 10 min exposure time, and a pH of 5, with 77.48 vs 78.14% corresponding to the predicted and empirically measured respectively. The photocatalytic degradation of MTZ was fitted with pseudo-first-order kinetic (R2 > 0.90). MTZ lost the antimicrobial activity against Bacillus cereus (B. cereus) and Escherichia coli (E. coli) after degradation with EG-ZnO NPs at the optimal conditions as determined in the optimization process. These findings reflect the important role ANFIS and ANN in predicting and optimising the efficacy of engineered nanomaterials, including EG-ZnO NPs, for antibiotic degradation.

Applicability of bio-synthesized nanoparticles in fungal secondary metabolites products and plant extracts for eliminating antibiotic-resistant bacteria risks in non-clinical environments.

The abundance of antibiotic-resistant bacteria in the prawn pond effluents can substantially impact the natural environment. The settlement ponds, which are the most common treatment method for farms wastewater, might effectively reduce the suspended solids and organic matter. However, the method is insufficient for bacterial inactivation. The current paper seeks to highlight the environmental issue associated with the distribution of antibiotic resistant bacteria (ARB) from prawn farm wastewater and their impact on the microbial complex community in the surface water which receiving these wastes. The inactivation of antibiotic-resistant bacteria in prawn wastewater is strongly recommended because the presence of antibiotic-resistant bacteria in the environment causes water pollution and public health issues. The nanoparticles are more efficient for bacterial inactivation. They are widely accepted due to their high chemical and mechanical stability, broad spectrum of radiation absorption, high catalytic activity, and high antimicrobial activity. Many studies have examined the use of fungi or plants extract to synthesis zinc oxide nanoparticles (ZnO NPs). It is evident from recent papers in the literature that green synthesized ZnO NPs from microbes and plant extracts are non-toxic and effective. ZnO NPs inactivate the bacterial cells as a function for releasing reactive oxygen species (ROS) and zinc ions. The inactivation of antibiotic-resistant bacteria tends to be more than 90% which exhibit strong antimicrobial behavior against bacterial species.

Bio-inspired ZnO NPs synthesized from Citrus sinensis peels extract for Congo red removal from textile wastewater via photocatalysis: Optimization, mechanisms, techno-economic analysis.

Textile industry is one of the most environmental unfriendly industrial processes due to the massive generation of colored wastewater contaminated with dyes and other chemical auxiliaries. These contaminants are known to have undesirable consequences to ecosystem. The present study investigated the best operating parameters for the removal of congo red (CR, as the model for dye wastewater) by orange peels extract biosynthesized zinc oxide nanoparticles (ZnO NPs) via photocatalysis in an aqueous solution. The response surface methodology (RSM) with ZnO NPs loadings (0.05-0.20 g), pH (3.00-11.00), and initial CR concentration (5-20 ppm) were used for the optimization process. The applicability of ZnO NPs in the dye wastewater treatment was evaluated based on the techno-economic analysis (TEA). ZnO NPs exhibited hexagonal wurtzite structure with = C-H, C-O, -C-O-C, CC, O-H as the main functional groups. The maximum degradation of CR was more than 96% with 0.171 g of ZnO NPs, at pH 6.43 and 5 ppm of CR and 90% of the R2 coefficient. The specific cost of ZnO NPs production is USD 20.25 per kg. These findings indicated that the biosynthesized ZnO NPs with orange peels extract provides alternative method for treating dye wastewater.

Influence of Nitrogen and Phosphorus on Microalgal Growth, Biomass, Lipid, and Fatty Acid Production: An Overview.

Microalgae can be used as a source of alternative food, animal feed, biofuel, fertilizer, cosmetics, nutraceuticals and for pharmaceutical purposes. The extraction of organic constituents from microalgae cultivated in the different nutrient compositions is influenced by microalgal growth rates, biomass yield and nutritional content in terms of lipid and fatty acid production. In this context, nutrient composition plays an important role in microalgae cultivation, and depletion and excessive sources of this nutrient might affect the quality of biomass. Investigation on the role of nitrogen and phosphorus, which are crucial for the growth of algae, has been addressed. However, there are challenges for enhancing nutrient utilization efficiently for large scale microalgae cultivation. Hence, this study aims to highlight the level of nitrogen and phosphorus required for microalgae cultivation and focuses on the benefits of nitrogen and phosphorus for increasing biomass productivity of microalgae for improved lipid and fatty acid quantities. Furthermore, the suitable extraction methods that can be used to utilize lipid and fatty acids from microalgae for biofuel have also been reviewed.

Supercritical fluid extraction of four aromatic herbs and assessment of the volatile compositions, bioactive compounds, antibacterial, and anti-biofilm activity.

Artemisia arborescens, Artemisia abyssinica, Pulicaria jaubertii, and Pulicaria petiolaris are fragrant herbs traditionally used in medication and as a food seasoning. To date, there are no studies on the use of supercritical fluids extraction with carbon dioxide (SFE-CO2) on these plants. This study evaluates and compares total phenolic content (TPC), antioxidant activity by DPPH• and ABTS•+, antibacterial, and anti-biofilm activities of SFE-CO2 extracts. Extraction was done by SFE-CO2 with 10% ethanol as a co-solvent. A. abyssinica extract had the highest extraction yield (8.9% ± 0.41). The GC/MS analysis of volatile compounds identified 307, 265, 213, and 201compounds in A. abyssinica, A. arborescens, P. jaubertii, and P. petiolaris, respectively. The P. jaubertii extract had the highest TPC (662.46 ± 50.93 mg gallic acid equivalent/g dry extract), antioxidant activity (58.98% ± 0.20), and antioxidant capacity (71.78 ± 1.84 mg Trolox equivalent/g dry extract). The A. abyssinica and P. jaubertii extracts had significantly higher antimicrobial activity and were more effective against Gram-positive bacteria. B. subtilis was the most sensitive bacterium. P. aeruginosa was the most resistant bacterium. P. jaubertii extract had the optimum MIC and MBC (0.4 mg/ml) against B. subtilis. All SFE-CO2 extracts were effective as an anti-biofilm formation for all tested bacteria at 1/2 MIC. Meanwhile, P. jaubertii and P. petiolaris extracts were effective anti-biofilm for most tested bacteria at 1/16 MIC. Overall, the results indicated that the SFE-CO2 extracts of these plants are good sources of TPC, antioxidants, and antibacterial, and they have promising applications in the industrial fields.

Efficiencies and mechanisms of steel slag with ferric oxides for removing phosphate from wastewater using a column filter system.

The current study aimed to investigate the efficiencies and mechanisms of slag filter media for removing phosphorus from synthetic wastewater. The steel slag with high ferric oxides (Fe2O3) was subjected for the electric arc furnace (EAF) and selected as the filter media (HFe). The chemical characteristics of HFe were determined using pH, point of zero charge (PZC) and XRF. The phosphorus removal efficiency was studied in a designed vertical steel slag column rock filters in unaerated HFe (UEF) and aerated HFe (AEF) system. The microstructure of HFe was analyzed by FTIR, XRD and SEM-EDX analysis. The results of XRF revealed that ferric oxide (Fe2O3) ranged from 26.1 to 38.2%. PZC for Filter HFe was recorded at pH 10.55 ± 0.27. The highest efficiencies were recorded by UEF and AEF systems at pH 3 and pH 5 (89.97 ± 4.02% and 79.95 ± 6.25% at pH 3 and 72.97 ± 8.38% and 66.00 ± 12.85% at pH 5 for UEF and AEF, respectively). These findings indicated that AEF exhibiting higher removal than UEF systems might be due to presence high Fe concentration in AEF which play important role in the phosphorus removal. The main elements available on the surface of HFe included carbon, oxygen, iron, calcium, magnesium, silicon, platinum, sulphur, manganese, titanium and aluminium. The XRD analysis indicated that the precipitation of orthophosphate as calcium and iron-phosphates was the removal mechanism as confirmed using FT-IR analysis. These findings demonstrated the efficiency of HFe in removing of phosphorus from wastewater.