Utilization of the copper recovered from waste printed circuit boards as a metal precursor for the synthesis of TiO2/magnetic-MOF(Cu) nanocomposite: Application in photocatalytic degradation of pesticides in aquatic solutions.

In this study, a number of leaching solutions (H2SO4, CuSO4 and NaCl) and an electrochemical method were used together for the separation of Cu from waste printed circuit boards. Secondly, the magnetic-MOF(Cu) was synthesized using the Cu recovered from waste printed circuit boards. Thereafter, TiO2/mag-MOF(Cu) composite was prepared and its photocatalytic activity was assessed in the photo degradation of two prominent organophosphorus pesticides, namely malathion (MTN) and diazinon (DZN). The catalytic structure of the MOF-based composite was fully characterized by various analyses such as XRD, SEM, EDAX, FT-IR, VSM and UV-vis. The obtained analyses confirmed the successful synthesis of TiO2/mag-MOF(Cu) composite. The synthesized composite exhibited highly efficient in the degradation of both pollutants under the following conditions: pH 7, contaminant concentration 1 mg/L, the catalyst dosage of 0.4 g/L, visible light intensity 75 mW/cm2 and reaction time of 45 min. First order kinetic model was best suited with the experimental results (R2: 0.97-0.99 for different MTN and DZN concentrations). Trapping studies revealed that superoxide radicals (O2•-) played an important role during the degradation process. Furthermore, the catalyst demonstrated a superb recovery as well as high stability over five cyclic runs of reuse. In addition, the total organic carbon (TOC) analysis showed over 83% and 85% mineralization for MTN and DZN, respectively. The combined system of TiO2/mag-MOF(Cu)/Vis also exhibited a great level of efficiency and feasibility in the treatment of tap water and treated wastewater samples. It is concluded that TiO2/mag-MOF(Cu) could be used as an excellent catalyst for the photodegradation of MTN and DZN in aqueous solution.

Upgrading the biogas production from raw landfill leachate using O3/H2O2 pretreatment process: Modeling, optimization and anaerobic digestion performance.

Here, a combined pretreatment oxidation process (O3/H2O2) was investigated to enhance the biodegradability of raw landfill leachate (RLL) and biomethane potential (BMP) in anaerobic reactors. The central composite design (CCD) and response surface methodology (RSM) were employed to optimize the operational parameters influencing on RLL bioavailability in O3/H2O2 process: pH, Oxygen Flow rate, Reaction Time, and H2O2 concentration. The findings revealed that the O3/H2O2 increased biodegradability index (BOD5/COD) of RLL from 0.41 to 0.68 under optimized condition (pH=8, Oxygen flow= 0.25 L.min-1, Reaction Time= 25 min, H2O2 concentration= 2.5 g.L-1). Furthermore, the effects of O3/H2O2 process on BMP of RLL were surveyed under mesophilic anaerobic reactors (Temperature: 37 ± 1 °C) in viewpoints of operational performance and methane yield in a batch mode for incubation period of 24 days. The results showed that O3/H2O2 process simultaneously improve the BMP by 2.99 times higher in a shorter lag-phase period (5 days) compared with control. The pretreatment O3/H2O2 and mesophilic anaerobic digestion process revealed a feasible and efficient method for enhance BMP of RLL.

Extraction and determination of organic/inorganic pollutants in the ambient air of two cities located in metropolis of Tehran.

In the present study, PM2.5, volatile organic compounds (VOC), heavy metals, and polycyclic aromatic hydrocarbons (PAHs)-bonded PM2.5 as well as asbestos fibers were investigated in two cities in the east of Tehran, Iran. To this end, 72 samples were collected from six stations located in the cities of Varamin and Pakdasht from March 2018 to March 2019. The concentration of BTEX compounds, PAHs, and heavy metals were measured using gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectrometry (GC-Mas), and inductively coupled plasma atomic emission spectroscopy (ICP-OES), respectively. In addition, phase contrast microscopy (PCM) method was used to identify the properties of asbestos fibers. The results obtained from the present showed that the mean concentrations of PM2.5, heavy metals, PAHs, BTEX, and asbestos fibers were 52.05 µg/m3, 319.08 ng/m3, 3.97 ng/m3, 40.58 µg/m3, and 2.84 f/L, respectively. In addition, the results obtained from PCA and heavy metals sources showed that transport fleets were the natural source of most of these pollutants. In case of PAH sources, transport and incineration of coal had the highest contribution in the emission. Furthermore, the risk assessment showed that most of the compounds have a higher risk value than the guideline value spatial distribution and also showed that stations close to airports, city terminals, and highways were more polluted than other parts of the city. Therefore, in order to have healthy air and with the least pollution, it seems necessary to formulate the necessary strategies in the cities of Varamin and Pakdasht.

Photocatalytic removal of bentazon by copper doped zinc oxide nanorods: Reaction pathways and toxicity studies.

In this study, bentazon herbicide was degraded photocatalytically by copper doped zinc oxide nanorods fabricated by using a facile co-precipitation method. The crystal structure, morphology, surface composition, functional groups on the surface and valence state of the nanorods were investigated by XRD, SEM-EDX, FTIR, and XPS material characterization techniques. Environmental parameters including solution pH, catalyst dose, bentazon concentration, purging gases, H2O2 content, organic compound type and reusability affecting the rate of photocatalytic degradation of bentazon were evaluated. Under the optimal conditions, [Bentazon]0 = 20 mg L-1, Cu-ZnO loading = 0.5 g L-1, H2O2 = 2 mM, pH = 7 and in the presence of oxygen gas, 100% of the herbicide was removed within 60 min. By raising bentazon concentration (10-50 mg L-1), kobs decreased to values between 0.14 and 0.006 min-1 and the calculated electrical energy per order (EEo) increased from 38.16 to 727.27 (kWh m-3), respectively. The degradation removal of the herbicide using the UV/Cu-ZnO method (98.28%) was higher than that of the UV/ZnO method (32.14%) process. Interestingly, the photocatalytic performances in the first and fifth reuse cycles during catalyst recyclability tests were found to be similar. Generally, the efficacy of the method in the decomposition of bentazon in drinking water (78.95%) and actual sewage (46.77%) declined because of the presence of other anions due to their role as a scavenger of photogenerated reactive species. Intermediate products in the photocatalytic degradation of bentazon identified by gas chromatography/mass spectrometry (GC/MS) analysis were 2-amino-N-isopropyl-benzamide, 2-amino-benzoic acid, N-isopropyl-2-nitro-benzamide, and acids such as pentenedioic acid, oxalic acid and propenoic acid. Furthermore, the main mechanism for the photocatalytic removal of bentazon was determined to be via attack by hydroxyl radicals (•OH). The results of toxicity in the photocatalytic removal of bentazon by D. magna showed LC50 and toxicity unit (TU) 48 h equal to 46.10 and 9.56 vol percent.

Occurrence, spatial distribution, seasonal variations, potential sources, and inhalation-based health risk assessment of organic/inorganic pollutants in ambient air of Tehran.

The present study evaluated the concentrations, spatial distribution, seasonal variations, potential sources, and risk assessment of organic/inorganic pollutants in ambient air of Tehran city. Totally, 180 air samples were taken from 9 sampling stations from March 2018 to March 2019 and were analyzed to determine the concentrations of organic pollutants (BTEX compounds and PM2.5-bound PAHs) plus inorganic pollutants (PM2.5-bound metals and asbestos fibers). The results revealed that the mean concentrations of ∑ PAHs, BTEX, ∑ heavy metals, and asbestos fibers were 5.34 ng/m3, 60.55 µg/m3, 8585.12 ng/m3, and 4.13 fiber/ml in the cold season, respectively, and 3.88 ng/m3, 33.86 µg/m3, 5682.61 ng/m3, and 3.21 fiber/ml in the warm season, respectively. Source apportionment of emission of the air pollutants showed that PAHs are emitted from diesel vehicles and industrial activities. BTEX and asbestos are also released mainly by vehicles. The results of the inhalation-based risk assessment indicated that the carcinogenic risk of PAHs, BTEX, and asbestos exceeded the recommended limit by The US environmental protection agency (US EPA) and WHO (1 × 10-4). The risk of carcinogenesis of heavy metal of lead and chromium also exceeded the recommended limit. Thus, proper management strategies are required to control the concentration of these pollutants in Tehran's ambient air in order to maintain the health of Tehran's citizens.

In vitro antibacterial activity of poly (amidoamine)-G7 dendrimer.

BACKGROUND: Nano-scale dendrimers are synthetic macromolecules that frequently used in medical and health field. Traditional anibiotics are induce bacterial resistence so there is an urgent need for novel antibacterial drug invention. In the present study seventh generation poly (amidoamine) (PAMAM-G7) dendrimer was synthesized and its antibacterial activities were evaluated against representative Gram- negative and Gram-positive bacteria. METHODS: PAMAM-G7 was synthesized with divergent growth method. The structural and surface of PAMAM-G7 were investigated by transmission electron microscopy, scanning electron microscope and fourier transform infrared. Pseudomonas. aeruginosa (n = 15), E. coli (n = 15), Acinetobacter baumanni (n = 15), Shigella dysenteriae (n = 15), Klebsiella pneumoniae (n = 10), Proteus mirabilis (n = 15), Staphylococcus aureus (n = 15) and Bacillus subtilis (n = 10) have been used for antibacterial activity assay. Additionally, representative standard strains for each bacterium were included. Minimum Inhibitory Concentration (MIC) was determined using microdilution method. Subsequently, Minimum Bactericidal Concentration (MBC) was determined by sub-culturing each of the no growth wells onto Mueller Hinton agar medium. The cytotoxicity of PAMAM-G7 dendrimer were evaluated in HCT116 and NIH 3 T3 cells by MTT assay. RESULTS: The average size of each particle was approximately 20 nm. PAMAM-G7 was potentially to inhibit both Gram positive and gram negative growth. The MIC50 and MIC90 values were determined to be 2-4 µg/ml and 4-8 µg/ml, respectively. The MBC50 and MBC90 values were found to be 64-256 µg/ml and 128-256 µg/ml, respectively. The cytotoxity effect of dendrimer on HCT116 and NIH 3 T3 cells is dependent upon exposure time to and concentration of dendrimers. The most reduction (44.63 and 43%) in cell viability for HCT116 and NIH 3 T3 cells was observed at the highest concentration, 0.85 µM after 72 h treatmentm, respectively. CONCLUSIONS: This study we conclude that PAMAM-G7 dendrimer could be a potential candidate as a novel antibacterial agent.

Enhancement of photocatalytic activity of Cu-doped ZnO nanorods for the degradation of an insecticide: Kinetics and reaction pathways.

The photocatalytic degradation of organophosphorus pesticide such as diazinon was investigated by Cu-doped ZnO nanorods. Cu-doped ZnO nanorods were synthesized via a facile co-precipitation method. The catalyst was characterized by XRD, FESEM, EDX, VSM, XPS, and pHzpc techniques. The effects of some operational parameters such as solution pH, Cu-doped ZnO nanorods dosage, initial diazinon concentration, oxygen and nitrogen gases, H2O2 concentration, and type of organic compounds on the degradation efficiency were discussed through the photocatalytic experiments using the Cu-doped ZnO nanorods. Neutral pH was selected as an optimal pH condition due to a photo-corrosion of ZnO in acidic and basic conditions. As the Cu-doped ZnO nanorods dosage increased up to 0.2 g/L, degradation efficiency of diazinon was continuously enhanced. Pseudo-first-order rate constant (kobs) was decreased from 0.051 to 0.0052 min-1 and electrical energy per order (EEo) was increased from 94.12 to 923.08 (kWh/m3) by increasing diazinon concentration from 10 to 50 mg/L, respectively. The efficiency of the UV/Cu-doped ZnO for diazinon removal was approximately 96.97%, which was more effective than the UV/ZnO process (58.52%). Photocatalytic activity was maintained even after five successive cycles.

Contaminants of emerging concern: a review of new approach in AOP technologies.

The presence of contaminants of emerging concern (CECs) such as pharmaceuticals and personal care products (PPCPs), endocrine-disrupting compounds (EDCs), flame retardants (FRs), pesticides, and artificial sweeteners (ASWs) in the aquatic environments remains a major challenge to the environment and human health. In this review, the classification and occurrence of emerging contaminants in aquatic environments were discussed in detail. It is well documented that CECs are susceptible to poor removal during the conventional wastewater treatment plants, which introduce them back to the environment ranging from nanogram per liter (e.g., carbamazepine) up to milligram per liter (e.g., acesulfame) concentration level. Meanwhile, a deep insight into the application of advanced oxidation processes (AOPs) on mitigation of the CECs from aquatic environment was presented. In this regard, the utilization of various treatment technologies based on AOPs including ozonation, Fenton processes, sonochemical, and TiO2 heterogeneous photocatalysis was reviewed. Additionally, some innovations (e.g., visible light heterogeneous photocatalysis, electro-Fenton) concerning the AOPs and the combined utilization of AOPs (e.g., sono-Fenton) were documented.

A comprehensive study on the spatial and temporal variation of BTEX and asbestos in the northwest of Iran: Human risk assessment.

Substances like asbestos and other air pollutants, such as BTEX (benzene, toluene, ethylbenzene, and xylene), are hazardous compounds due to their adverse effects on human health. This study aims to investigate the levels, seasonal variations, spatial distribution, potential sources, and associated health risks associated with BTEX compounds and asbestos fibers in the ambient air of Tabriz. Air samples were taken at 16 different locations during the 2020-2021 period. Glass containers with charcoal were used for sample collection, and the BTEX content was determined using the GC-FID method. Phase-contrast microscopy (PCM) analysis was conducted with a low-volume peripheral pump for asbestos fiber sampling. The results showed that the average concentration of ∑BTEX was 37.94 and 27.98 µg/m3 in autumn and spring, respectively. The same parameter was 2.26 and 1.68 f/L for asbestos in the autumn and winter, respectively. The contribution of BTEX to ozone formation potential (OFP) in the research area showed that xylene and toluene were the major contributors to ozone production in different seasons. The risk of exposure to benzene compounds was 24 × 10-4 in children and 55.9 × 10-4 in adults, while the risk of exposure to ethylbenzene was 3.78 × 10-4 in children and 3.25 × 10-4 in adults. The estimated lifetime cancer risk was found to be the highest for benzene, followed by ethylbenzene. The estimated cancer risk for benzene and ethylbenzene exceeded the threshold values set by EPA, which signals a significant carcinogenic risk due to exposure to these substances in the ambient air of Tabriz. According to the EPA guidelines, the low carcinogenicity risk levels are between 10-4 and 10-6. According to the findings for the exposure to asbestos fibers, the maximum values of excess cancer risk (ECR) and estimated lifetime cancer risk (ELCR) were observed in the 16-30 age range across all locations, suggesting increased exposure to asbestos fibers compared to other age groups.

Novel nanostructure approach for antibiotic decomposition in a spinning disc photocatalytic reactor.

Conventional wastewater treatment processes are often unable to remove antibiotics with resistant compounds and low biological degradation. The need for advanced and sustainable technologies to remove antibiotics from water sources seems essential. In this regard, the effectiveness of a spinning disc photocatalytic reactor (SDPR) equipped with a visible light-activated Fe3O4@SiO2-NH2@CuO/ZnO core-shell (FSNCZ CS) thin film photocatalyst was investigated for the decomposition of amoxicillin (AMX), a representative antibiotic. Various characterization techniques, such as TEM, FESEM, EDX, AFM, XRD, and UV-Vis-DRS, were employed to study the surface morphology, optoelectronic properties, and nanostructure of the FSNCZ CS. Key operating parameters such as irradiation time, pH, initial AMX concentration, rotational speed, and solution flow rate were fine-tuned for optimization. The results indicated that the highest AMX decomposition (98.7%) was attained under optimal conditions of 60 min of irradiation time, a rotational speed of 350 rpm, a solution flow rate of 0.9 L/min, pH of 5, and an initial AMX concentration of 20 mg/L. Moreover, during the 60 min irradiation time, more than 69.95% of chemical oxygen demand and 61.2% of total organic carbon were removed. After the photocatalytic decomposition of AMX, there is a substantial increase in the average oxidation state and carbon oxidation state in SDPR from 1.33 to 1.94 and 3.2, respectively. Active species tests confirmed that ·OH and ·O2- played a dominant role in AMX decomposition. The developed SDPR, which incorporates a reusable and robust FSNCZ CS photocatalyst, demonstrates promising potential for the decomposition of organic compounds.

Measurement and health risks assessment of BTEX compounds exposure in beauty Lahijan City salons.

The presence of BTEX (Benzene, Toluene, Ethylbenzene, and Xylene) compounds in beauty salons has raised concerns about potential health risks. This study aimed to measure the levels of BTEX compounds in the air of beauty salons in Lahijan, Iran and assess the associated health risks. Air samples were collected from 15 beauty salons, and the concentrations of BTEX compounds were measured according to 1501 NIOSH standard method. The results showed that the mean concentrations of benzene (20.62 µg/m3), toluene (18.3 µg/m3), ethylbenzene (38.36 µg/m3), and O and P-xylene (27.35, 23.6 µg/m3) were above the recommended levels. The indoor to outdoor ratios for benzene, toluene, ethylbenzene, O and P-xylene were 3.04, 2.36, 3.75, 4.89, and 6.54, respectively. Also, the toluene/benzene (T/B) ratio in indoor and outdoor was 20.9 and 2.68 respectively. Almost half of the technicians (49.12%) reported adverse health effects, including joint pain, itchy eyes and nose, and respiratory allergies. The IARC guideline suggests that there is a potential risk of cancer development for individuals in all salons with LCR values exceeding 10-6, but the HQ index values indicate no non-carcinogenic risk. The findings suggest that beauty salon workers and customers are at risk of developing health problems from exposure to BTEX compounds. Effective risk management strategies, such as proper ventilation, use of personal protective equipment, and substitution of harmful chemicals with safer alternatives, to minimize exposure and protect the health of salon workers and customers recommended.

Photocatalytic degradation of ciprofloxacin using a novel carbohydrate-based nanocomposite from aqueous solutions.

Pharmaceutical substances in the ecosystem pose a notable hazard to human and aquatic organism well-being. The occurrence of ciprofloxacin (CIP) within water sources or the food chain can perturb plant biochemical processes and induce drug resistance in both humans and animals. Therefore, effective removal is imperative prior to environmental discharge. This study introduces a Novel Carbohydrate-Based Nanocomposite (Fe3O4/MOF/AmCs-Alg) as a proficient photocatalytic agent for degrading CIP in aqueous solutions. The fabricated nanocomposite underwent characterization using FTIR, XRD, FESEM, DRS, and VSM techniques. The analyses conducted verified the successful synthesis of the Fe3O4/MOF/AmCs-Alg nanocomposite. Utilizing the optimized parameters (pH = 5, nanocomposite dose = 0.4 g/L, CIP concentration = 10 mg/L, light intensity = 75 mW/cm2, and a duration of 45min), the Fe3O4/MOF/AmCs-Alg/Vis nanocomposite demonstrated an impressive CIP degradation efficiency of 95.85%. Under optimal experiment conditions, CIP removal efficiency in tap water and treated wastewater samples was 91.27% and 76.78%, respectively. Furthermore, the total organic carbon (TOC) analysis indicated a mineralization rate of 51.21% for CIP. Trapping studies demonstrated that the superoxide radical (O2°-) had a notable contribution to the breakdown of CIP. In summary, the Fe3O4/MOF/AmCs-Alg/Vis system offers numerous benefits, encompassing effective degradation capabilities, effortless catalyst retrieval, and remarkable nanocomposite reusability.

Biosolids, an important route for transporting poly- and perfluoroalkyl substances from wastewater treatment plants into the environment: A systematic review.

The pervasive presence of poly- and perfluoroalkyl substances (PFAS) in diverse products has led to their introduction into wastewater systems, making wastewater treatment plants (WWTPs) significant PFAS contributors to the environment. Despite WWTPs' efforts to mitigate PFAS impact through physicochemical and biological means, concerns persist regarding PFAS retention in generated biosolids. While numerous review studies have explored the fate of these compounds within WWTPs, no study has critically reviewed their presence, transformation mechanisms, and partitioning within the sludge. Therefore, the current study has been specifically designed to investigate these aspects. Studies show variations in PFAS concentrations across WWTPs, highlighting the importance of aqueous-to-solid partitioning, with sludge from PFOS and PFOA-rich wastewater showing higher concentrations. Research suggests biological mechanisms such as cytochrome P450 monooxygenase, transamine metabolism, and beta-oxidation are involved in PFAS biotransformation, though the effects of precursor changes require further study. Carbon chain length significantly affects PFAS partitioning, with longer chains leading to greater adsorption in sludge. The wastewater's organic and inorganic content is crucial for PFAS adsorption; for instance, higher sludge protein content and divalent cations like calcium and magnesium promote adsorption, while monovalent cations like sodium impede it. In conclusion, these discoveries shed light on the complex interactions among factors affecting PFAS behavior in biosolids. They underscore the necessity for thorough considerations in managing PFAS presence and its impact on environmental systems.

The spinning disc reactor for photocatalytic degradation: A systematic review.

In recent years, the use of a horizontal spinning disc reactor (SDR) as a photocatalytic reactor for the degradation of various pollutants in aqueous solutions has increased. This study was searched based on the PRISMA method. Two autonomous researchers carried out for the relevant studies using Scopus, Web of Science (WOS), and Science Direct databases. The search terms expanded focusing on the performance of horizontal spinning disc photocatalytic reactor (SDPR). In this review article, the main objective of the effect of operational factors on the efficiency of the degradation of pollutants with changes in the type of light source (range of visible light and UV radiation), disc rotational speed, flow rate, initial concentration of pollutants, pH, type of disc structure and flow regime are considered. Current challenges in SDPR include issues such as limited mass transfer, uneven light distribution, and difficulties in scaling up. To overcome these challenges, improvements can be made by optimizing reactor design for better mass transfer, enhancing light distribution through advanced light sources or reactor configurations, and developing scalable models that maintain efficiency at larger scales. Additionally, the use of innovative materials and coatings could improve the overall performance of SDPR.

Simultaneous derivatization and extraction of nitrophenols in soil and rain samples using modified hollow-fiber liquid-phase microextraction followed by gas chromatography-mass spectrometry.

A simple and sensitive method based on a modified hollow-fiber liquid-phase microextraction followed by gas chromatography-mass spectrometry has been successfully developed for the extraction and simultaneous derivatization of some nitrophenols (NPs) in soil and rain samples. Microwave-assisted solvent extraction was used for the extraction of NPs from the soil, while the rain sample was directly applied to the previously mentioned method. Briefly, in this method, the analytes were extracted from aqueous samples into a thin layer of organic solvent (dodecane + 10% tri-n-octylphosphine oxide) sustained in the pores of a porous hollow fiber. Then, they were back-extracted using a small volume of organic acceptor solution (25 µl; 10 mg/L N-methyl-N-(trimethylsilyl)trifluoroacetamide, as derivatization reagent, in acetonitrile) that was located inside the lumen of the hollow fiber. Under the optimized extraction conditions, enrichment factors of 255 to 280 and limits of detection of 0.1 to 0.2 µg/L (S/N = 3) with dynamic linear ranges of 1-100 µg/L were obtained for the analytes. The accuracy of the approach was tested by the relative recovery experiments on spiked samples, with results ranging from 93 to 113%. The method was shown to be rapid, cost-effective, and potentially interesting for screening purposes.

Synthesis and characterization of rGO/Fe0/Fe3O4/TiO2 nanocomposite and application of photocatalytic process in the decomposition of penicillin G from aqueous.

In this study, we synthesized rGO/Fe0/Fe3O4/TiO2 nanocomposite according to Hummer's, and straightforward sol-gel method. The FESEM, EDX, TEM, FT-IR, XRD, BET, UV spectra, and VSM analysis were applied to determine the catalyst properties. Optimization of influence parameters on photocatalytic process performance to penicillin G degradation in aqueous media. pH (4-8), nanocomposite dose (10-20 mg/L), reaction time (30-60 min), and penicillin G concentration (50-100 mg/L) were optimized via central composite design. In the optimum condition of PCP, supplementary studies were done. As a result of the analysis, the nanocomposite was well synthesized and displayed superior photocatalytic properties for degrading organic pollutants. In addition to being magnetically separable, the synthesized rGO/Fe0/Fe3O4/TiO2 nanocomposite exhibits high recyclability up to 5 times. The quadratic model of optimization is based on the adjusted R2(0.99), and predicated R2(0.97) suggested. According to the analysis of variance test, the model was significant (F-Value = 162.95, P-Value = 0.0001). Photocatalytic process is most efficiently decomposed at pH = 6.5, catalyst dose = 18.5 mg/L, reaction time = 59.1 min, and penicillin G concentration = 52 mg/L (efficiency = 96%). The chemical oxygen demand and total organic carbon decrease were 78, and 65%. The photolysis and adsorption mechanism as a single mechanism had lower performance in penicillin G degradation. Benzocaine had the greatest effect on reducing the efficiency of the process as a radical scavenger. The °OH, h+, and O2●- were the main reactive oxidant species in penicillin G removal. Phenoxyacetaldehyde, Acetanilide, Diacetamate, Phenylalanylglycine, N-Acetyl-l-phenylalanine, Diformyldapsone, and Succisulfone were the main intermediates in penicillin G degradation. The results indicated the photocatalytic process with rGO/Fe0/Fe3O4/TiO2 nanocomposite on a laboratory scale has good efficiency in removing penicillin G antibiotic. The application of real media requires further studies.

Microplastics removal technologies from aqueous environments: a systematic review.

Purpose: Pollution of the environment with all kinds of plastics has become a growing problem. The problem of microplastics is mainly due to the absorption of stable organic pollutants and metals into them, and as a result, their environmental toxicity increases. The main purpose of this study is to investigate the appropriate and efficient methods of removing microplastics from aqueous environments through a systematic review. Methods: Present study designed according to PRISMA guidelines. Two independent researchers followed all process from search to final analysis, for the relevant studies using international databases of PubMed, Scopus and ISI/WOS (Web of Science), without time limit. The search strategy developed based on the main axis of "microplastics", "aqueous environments" and "removal". This research was carried out from 2017 until the March of 2022. All relevant observational, analytical studies, review articles, and a meta-analysis were included. Results: Through a comprehensive systematic search we found 2974 papers, after running the proses of refining, 80 eligible papers included to the study. According to the results of the review, the methods of removing microplastics from aquatic environments were divided to physical (12), chemical (18), physicochemical (27), biological (12) and integrated (11) methods. In different removal methods, the most dominant group of studied microplastics belonged to the four groups of polyethylene (PE), polystyrene (PS), polypropylene (PP) and polyethylene tetra phthalate (PET). Average removal efficiency of microplastics in different processes in each method was as: physical method (73.76%), chemical method (74.38%), physicochemical method (80.44%), biological method (75.23%) and integrated method (88.63%). The highest removal efficiency occurred in the processes based on the integrated method and the lowest efficiency occurred in the physical method. In total, 80% of the studies were conducted on a laboratory scale, 18.75% on a full scale and 1.25% on a pilot scale. Conclusion: According to the findings; different processes based on physical, chemical, physicochemical, biological and integrated methods are able to remove microplastics with high efficiency from aqueous environments and in order to reduce their hazardous effects on health and environment, these processes can be easily used.

A comparative study on polyaluminum chloride (PACl) and Moringa oleifera (MO) chemically enhanced primary treatment (CEPT) in enhanced biogas production: anaerobic digestion performance and the Gompertz model.

A comparative study was performed to estimate biogas production from sludge produced by organic and inorganic chemically enhanced primary treatments (CEPTs). To this end, the effects of two coagulants, polyaluminum chloride (PACl) and Moringa oleifera (MO), on CEPT and biogas production in anaerobic digestion were surveyed within an incubation period of 24 days. The optimal dosage and pH of PACl and MO were optimized in terms of sCOD, TSS and VS parameters in the CEPT process. Next, the digestion performance of anaerobic digestion reactors fed with sludge obtained from PACl and MO coagulants at a batch mesophilic reactor (37 ± 1 °C) was surveyed from the biogas production, volatile solid reduction (VSR) and Gompertz model. At the optimal conditions (pH = 7 and dosage = 5 mg L-1), the removal efficiency of COD, TSS and VS in CEPT assisted with PACL was 63, 81 and 56%, respectively. Moreover, CEPT assisted with MO led to the removal efficiency of COD, TSS and VS until 55, 68 and 25%, respectively. The highest methane yield (0.598 L gVS removed-1) was obtained in an anaerobic digestion reactor with sludge from the MO coagulant. The anaerobic digestion of CEPT sludge instead of primary sludge resulted in higher sCOD removal efficiency, and 43-50% of sCOD was observed compared with the removal of 32% for the primary sludge. Furthermore, the high coefficient of determination (R2) demonstrated the trustworthy predictive precision of the modified Gompertz model with actual data. The combination of CEPT and anaerobic digestion, especially using natural coagulants, provides a cost-effective and practical way to increase BMP from primary sludge.

Photocatalytic degradation of chlorpyrifos using Ag nanoparticles-doped g-C3N5 decorated with dendritic CdS.

In this work, g-C3N5/CdS dendrite/AgNPs nanocomposite was synthesized using a mixed method consisting of hydrothermal, ultrasonic and chemistry reduction with sodium borohydride. The characterization of the as-prepared nanocomposite was done using infrared spectroscopy, X-ray, scanning electron microscopy, transmission electron microscopy, BET, and DRS methods was performed. The DRS results showed that the g-C3N5/CdS dendrite/AgNPs nanocomposite nanocomposite has a band gap of 1.08 eV. This band gap indicates the good capability of this nanocomposite as a photocatalyst. Accordingly, the photocatalytic degradation of chlorpyrifos (CPS) in was performed in an aqueous solution of the synthesized nanocomposite. The results showed that almost 95.3% of this poison, a concentration of 50 mg L-1 was degraded in the presence of 0.05 g L-1 of nanocomposite at pH = 5 in a 60 min. Hydroxide radicals and holes play a significant role in the photocatalytic process. The reusability of the nanocomposite with excellent performance in the degradation of photocatalytic toxins caused by the reduction in the electron-hole recombination and the high surface area of the nanocomposite are among the unique features of this work.

Simulation of the potential impact of climate change on malaria incidence using artificial neural networks (ANNs).

Climate change can increase the spread of infectious diseases and public health concerns. Malaria is one of the endemic infectious diseases of Iran, whose transmission is strongly influenced by climatic conditions. The effect of climate change on malaria in the southeastern Iran from 2021 to 2050 was simulated by using artificial neural networks (ANNs). Gamma test (GT) and general circulation models (GCMs) were used to determine the best delay time and to generate the future climate model under two distinct scenarios (RCP2.6 and RCP8.5). To simulate the various impacts of climate change on malaria infection, ANNs were applied using daily collected data for 12 years (from 2003 to 2014). The future climate of the study area will be hotter by 2050. The simulation of malaria cases elucidated that there is an intense increasing trend in malaria cases under the RCP8.5 scenario until 2050, with the highest number of infections occurring in the warmer months. Rainfall and maximum temperature were identified as the most influential input variables. Optimum temperatures and increased rainfall provide a suitable environment for the transmission of parasites and cause an intense increase in the number of infection cases with a delay of approximately 90 days. ANNs were introduced as a practical tool for simulating the impact of climate change on the prevalence, geographic distribution, and biological activity of malaria and for estimating the future trend of the disease in order to adopt protective measures in endemic areas.