Sustainable removal of tetracycline and paracetamol from water using magnetic activated carbon derived from pine fruit waste

This work presents highly porous magnetic activated carbon nanoparticles (MPFRC-A) derived from pine fruit residue. The MPFRC-A were produced through a three-step process: physical activation (carbonization temperature: 110-550 °C), chemical activation (H2SO4 (0.1 N, 96%)), and co-precipitation. These nanoparticles were then used to remove tetracycline (TC) and paracetamol (PC) from water. Functionalization with Fe3O4 nanoparticles on the surface of the pine fruit residue-derived activated carbon (PFRC-A) resulted in high saturation magnetization, allowing for separation from aqueous solution using an external magnet. The MPFRC-A adsorbent was characterized by Brunauer-Emmett-Teller (BET) analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Energy-dispersive X-ray spectroscopy (EDX) analyses, In the experimental section, the effects of various factors on the adsorption process were investigated, including pH, contact time, initial pollutant concentrations, adsorbent dosage, and temperature. Based on these investigations, adsorption isotherm models and kinetics were studied and determined. The results showed that MPFRC-A exhibited a large specific surface area (182.5 m2/g) and a high total pore volume (0.33 cm3/g). The maximum adsorption capacity was achieved at pH 6 and 5 for PC and TC drugs with an adsorbent dose of 400 mg and an initial concentration of 20 mg/L at 25 °C. The study revealed that the experimental data were well-fitted by the Langmuir isotherm model (R2 > 0.98), with maximum uptake capacities of 43.75 mg/g for TC and 41.7 mg/g for PC. Outcomes of the adsorption thermodynamics shows non-spontaneity of the reaction and the adsorption process by all adsorbents was endothermic.

Removal of metronidazole using a novel ZnO-CoFe2O4@Biochar heterostructure composite in an intimately coupled photocatalysis and biodegradation system under visible light

The intimate coupling of photocatalysis and biodegradation (ICPB) technology has received much attraction because of the advantages of both photocatalytic reaction and biological treatment. In this study, ZnO-CoFe2O4@BC (ZCFC) with p-n heterojunction was prepared and used in an ICPB system to degrade metronidazole (MNZ) wastewater. The microstructure, morphology, and optical behavior of heterojunctions in ZCFC were investigated using SEM, XRD, UV-vis, FTIR, and XPS techniques. The results showed that ZCFC inherited the advantages of bamboo biochar's large pore size, and its large pore structure could provide a habitat for bacterial colonization in ICPB, thus shortening the internal mass transfer distance. The degradation of MNZ and chemical oxygen demand (COD) by the ICPB system was 86.8% and 58.5%, respectively, which was superior to single photocatalysis (72.5% for MNZ and 43.8% for COD) and single biodegradation (23.5% for MNZ and 20.1% for COD). In ICPB, photocatalysis and biodegradation showed a synergistic effect in the removal of MNZ, and the order of the major reactive oxygen species (ROS) leading to reduced toxicity of MNZ to the biofilm was •OH > h+ > O2•-. High-throughput sequencing analysis showed continuous evolution of biofilm structures in ICPB enriched a variety of functional species, among which the electroactive bacteria Alcaligenes and Brevundimonas played an important role in the degradation of MNZ. In this study, we investigated the possible mechanism of photocatalytic and microbial synergistic degradation of MNZ in the ICPB system and proposed a new technology for degrading antibiotic wastewater that combines the advantages of photocatalysis and biodegradation.

Research progress on the generation of NDMA by typical PPCPs in disinfection treatment of water environment in China: A review

The drugs and personal care products in water sources are potential threats to the ecological environment and drinking water quality. In recent years, the presence of PPCPs has been detected in multiple drinking water sources in China. PPCPs are usually stable and resistant to degradation in aquatic environments. During chlorination, chloramination, and ozonation disinfection processes, PPCPs can act as precursor substances to generate N-nitrosodimethylamine (NDMA) which is the most widely detected nitrosamine byproduct in drinking water. This review provides a comprehensive overview of the impact of PPCPs in China's water environment on the generation of NDMA during disinfection processes to better understand the correlation between PPCPs and NDMA generation. Chloramine is the most likely to form NDMA with different disinfection methods, so chloramine disinfection may be the main pathway for NDMA generation. Activated carbon adsorption and UV photolysis are widely used in the removal of NDMA and its precursor PPCPs, and biological treatment is found to be a low-cost and high removal rate method for controlling the generation of NDMA. However, there are still certain regional limitations in the investigation and research on PPCPs, and other nitrosamine by-products such as NMEA, NDEA and NDBA should also be studied to investigate the formation mechanism and removal methods.

Hidden ecotoxicological dangers: Investigating pathogen circulation and non-toxic risks hazards in a crucial brazilian watershed

Numerous studies evaluate chemical contaminants released by human activities and their effects on biota and aquatic ecosystems. However, few of these studies address non-toxic agents and their potentially harmful effects, which, in a concealed manner, culminate in an increased ecotoxicological risk for aquatic life and public health. This study investigated the presence of toxic and non-toxic pollutants in one of the main watersheds in Northeast Brazil (Rio São Francisco) and proposed a model of dispersion and transfer of resistance among the analyzed bacteria, also assessing the health risks of individuals and aquatic organisms present there. The results are worrying because although most toxic parameters, including physical-chemical and chromatographic aspects, comply with Brazilian environmental standards, non-toxic (microbiological) parameters do not. This research reveals the circulation of pathogens in several points of this hydrographic basin, highlighting the hidden ecotoxicological potential of an aquatic environment considered unaffected by the usual patterns of toxic parameters.

Genomic analysis of multidrug-resistant Escherichia coli from Urban Environmental water sources in Accra, Ghana, Provides Insights into public health implications

Wastewater discharge into the environment in resource-poor countries poses a threat to public health. Studies in this area within these countries are limited, and the use of high-throughput whole-genome sequencing technologies is lacking. Therefore, understanding of environmental impacts is inadequate. The present study investigated the antibiotic resistance profiles and diversity of beta-lactamases in Escherichia coli strains isolated from environmental water sources in Accra, Ghana. Microbiological analyses were conducted on wastewater samples from three hospitals, a sewage and wastewater treatment plant, and water samples from two urban surface water bodies. Confirmed isolates (N = 57) were selected for phenotypic antibiotic resistance profiles. Multi-drug-resistant isolates (n = 25) were genome sequenced using Illumina MiSeq sequencing technology and screened for sequence types, antibiotic resistance, virulence and beta-lactamase genes, and mobile genetic elements. Isolates were frequently resistant to ampicillin (63%), meropenem (47%), azithromycin (46%), and sulfamethoxazole-trimethoprim (42%). Twenty different sequence types (STs) were identified, including clinically relevant ones such as ST167 and ST21. Five isolates were assigned to novel STs: ST14531 (n = 2), ST14536, ST14537, and ST14538. The isolates belonged to phylogroups A (52%), B1 (44%), and B2 (4%) and carried β-lactamase (TEM-1B, TEM-1C, CTX-M-15, and blaDHA-1) and carbapenemase (OXA-1, OXA-181) resistance genes. Dominant plasmid replicons included Col440I (10.2%) and IncFIB (AP001918) (6.8%). Polluted urban environments in Accra are reservoirs for antibiotic-resistant bacteria, posing a substantial public health risk. The findings underscore the need for targeted public health interventions to mitigate the spread of antibiotic-resistant bacteria and protect public health.

Occurrence, spatial and seasonal variations of emerging contaminants in the aquatic environment of Sharjah, United Arab Emirates

The occurrence, seasonal variations and spatial distribution of emerging contaminants (ECs) in wastewater effluents from wastewater treatment plant (WWTP) and UAE's receiving coastal aquatic environment (seawater and sediments) were evaluated in the present study. A total of 21, 23, and 22 contaminants in the effluents, seawater, and sediments, respectively, at concentrations ranging from low ng L-1 up to 1782 ng L-1 in effluents, from low ng/l up to 236.10 ng L-1 in seawater, and from low ng g-1 up to 60.15 ng g-1 in sediments were recorded. The study revealed that imidacloprid, thiabendazole, and acetaminophen were the most ubiquitous compounds in effluents, seawater, and sediments, respectively, since they were found in all samples collected with a detection frequency of 100%. The study also revealed that the higher concentrations of most contaminants were recorded in autumn. However, thiabendazole in effluents and seawater, acetamiprid in effluents, and sulphapyridine in seawater and sediments showed a higher load in winter. This study highlights the need for proper monitoring and management of ECs in wastewater effluents, seawater, and sediments, especially during the autumn and winter seasons, to minimize their impact on the marine ecosystem and public health.

Risk Threshold and Assessment of Chloramphenicol Antibiotics in Sediment in the Fenhe River Basin, China

Chloramphenicol antibiotics (CAs) are broad-spectrum antibiotics which are widely used in the prevention and treatment of infectious diseases in livestock and poultry breeding. However, overused CAs can enter the watershed and eventually enter the sediment. Antibiotics in sediment can cause secondary pollution through disturbance and suspension. In this study, taking the Fenhe River Basin as the research area, the risk of CAs in sediment were assessed by collecting sediment samples. The results showed that CAs were detected in all sediment samples of the Fenhe River Basin. The mean concentration of CAs was 79.1 μg/kg, and the concentration of thiamphenicol (THI) was dominant, which was up to 58.3 μg/kg. Temporally, there are great differences in different seasons; the concentration of CAs was higher in winter than that in summer, up to 4.79-174 times. Spatially, the mean concentration of CAs in midstream was 83.5 μg/kg, which was higher than that in the upstream and downstream. The concentration of CAs in tributaries were generally higher than that in the main stream, and the mean concentration of tributaries was 1.1 times that of the main stream. CAs in S2 (Lanhe River) was the most prominent among all sample sites; the concentration of CAs was 190.8 μg/kg. The risk threshold of CAs in the sediment was calculated using the Equilibrium Partitioning approach (EqP), based on the distribution coefficient (Kp) and the predicted no-effect concentration (PNEC) in the water, and the values were 0.091-1.44 mg/kg. Based on the risk threshold, the ecological risk of the CAs in sediment was assessed using risk quotients (RQ). The results showed that the Chloramphenicol (CHL) was the most prominent in the Fenhe River Basin, and the proportion of medium-risk areas reached 21.7%, while all the other areas showed low risk. Secondly, the proportion of medium-risk areas was 17.4% for THI, and all the other areas showed low risk. The risk for Florfenicol (FF) was least among all CAs, and the proportion of low-risk areas was only 8.7%, while all the other areas were of insignificant risk.

Disposal of Unused and Expired Medicines within the Sunyani Municipality of Ghana: A Cross-Sectional Survey

The occurrence of pharmaceuticals in the environment is a global challenge. Pharmaceuticals such as antibiotics and analgesics have been reported in various environmental matrices at varying concentrations. The major disposal route for unused and expired pharmaceuticals in Ghana is throwing them into dustbins. Although there are laws on the proper disposal patterns of drugs, these laws are poorly implemented. Sunyani is a fast-growing community with several health facilities that dispense medications daily. The purchase and use of medications among households are also high. However, no data exist on the disposal patterns of pharmaceuticals within the Sunyani Municipality. This study aims to identify the disposal patterns for unused and expired medications by households and pharmacies within the Sunyani Municipality, Ghana. A descriptive cross-sectional study was conducted among 400 persons in homes and 35 persons from randomly selected pharmacies and over-the-counter medication shops (OTCMs) within the Sunyani Municipality. A face-to-face interview approach using structured questionnaires for each respondent was employed. Household respondents disposed of unused and expired medications mainly through dumping in garbage cans (70.8%), incineration (11.5%), and flushing down the sink (9%). Pharmaceutical shop respondents also disposed of unused and expired medications into dump cans, by incineration, through the Food and Drugs Authority of Ghana, and took back to pharmaceutical wholesalers. Disposal practices observed in this study by households and pharmacy respondents were largely inappropriate. This could be due to the lack of education on the proper disposal patterns available to these respondents. It is recommended that guidelines on safe disposal be put in place, and a structured procedure for collecting unused and expired pharmaceuticals should be introduced.