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Human-generated waste, including infectious healthcare waste, poses significant risks to public health and the environment. The COVID-19 pandemic has increased the global production of infectious waste, emphasizing the need for safe and sustainable waste management practices. While autoclaves are commonly used for on-site disposal, alternative methods like ozone gas and UV-C radiation offer environmentally friendly options that effectively eliminate pathogens without leaving toxic residues. Inadequate waste management can contribute to disease transmission, while open burning releases harmful pollutants. This study investigated the effectiveness of different disinfection agents – ozone gas and UV-C radiation – on infectious solid waste contaminated with bacteria. The bacterial indicators examined were Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa. The experimental methods included operating each ozone and UV-C radiation individually and simultaneously using ozone gas and UV-C radiation. The study also investigated exposure times and various concentrations of ozone gas. The findings demonstrated that the simultaneous application of ozone gas and UV-C radiation was the most effective method for decontaminating infectious solid waste and targeting the selected bacteria. The concentration of ozone gas ranged from 165 to 5000 ppm, depending on generation time and treatment chamber volume, while exposure times varied from 1 to 180 minutes. In applying UV-C rays, complete elimination of S. aureus was observed after 60 minutes up to 6-log, while the reduction of B. subtilis and P. aeruginosa were 2-log and 3-log, respectively. Ozone gas had the ability to inactivate all strains, but when ozone gas and UV-C rays were used simultaneously, this process was accelerated and improved. The total reduction in the bacterial load was 8-log. Considering the increase in population and the subsequent increase in waste generation, adopting an environmentally friendly waste management method can be very advantageous. Implications: This study highlights the effectiveness of simultaneously applying ozone gas and UV-C radiation for decontaminating infectious solid waste, offering an environmentally friendly alternative to traditional thermal treatments like autoclave and incineration. By optimizing ozone concentrations and exposure times, this method reduces disease transmission risks and minimizes environmental impact. These findings are crucial, especially during outbreaks such as the COVID-19 pandemic, providing scalable, sustainable waste management solutions for healthcare facilities. Implementing these techniques can protect public health and the environment, setting a new standard for safe infectious waste disposal worldwide, mitigating hazardous pollutants, and reduce the exposure risk of bio-hazardous residues. [ABSTRACT FROM AUTHOR]

Numerous tons of hazardous wastes containing persistent organic pollutants (POPs) are stored in an unsafe manner in the petrochemical industries. The planetary ball mill causes the formation of mineral Cl compounds during the degradation of polychlorinated compounds in the presence of various reagents. In addition, the planetary ball mill has been applied for the synthesis of diverse organic-inorganic hybrid nanomaterials. In the present study, Fe-metal organic framework was prepared using a planetary ball mill, and then Fe@C nanocomposite with core/shell structure was synthesised by carbonisation. X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) were utilised to study the synthesised materials. The nanocomposite was used as a reagent to degrade persistent organic pollutants in the sludge of a petrochemical wastewater treatment plant by a planetary ball mill. CaO was also used to compare the effect of nanocomposites on system performance. Ion chromatography (IC) analysis was carried out to determine chlorine mineralisation. Furthermore, Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy were applied to determine chemical bonds. The results illustrated a zero-valent iron nanoparticle in the core protected by carbon shell in a synthesised nanocomposite with a core/shell structure. Hence, nanocomposite was the most efficient additive, with 97% dechlorination efficiency in the first hour while the efficiency of the planetary ball mill in the presence of CaO was only 76% after 12 hours of milling. Furthermore, major changes occurred in the organic phases, carbon and chlorine bonds. Simultaneously, graphite and amorphous carbon were produced in the final products after milling. This indicates that aromatic structures and C-Cl bonds were broken down into inorganic compounds. Thus, this study presented a practical method of producing materials while degrading hazardous pollutants in petrochemical wastewater sludge through a planetary ball mill. [ABSTRACT FROM AUTHOR]

Cuprospinel nanoparticles (CuFe2O4-NPs) were initially made in this study using the sol-gel process. Then, the effect of the main operational parameters, such as sulphate radical precursors (namely, peroxymonosulfate [PMS] and peroxydisulfate [PDS]), pH of aqueous solution, ultrasound (US) frequency and power, CuFe2O4 loading, reaction time, atenolol (ATL) concentration, as well as inorganic anions on the sonocatalytic process in removing ATL from water was investigated. The results revealed that the PMS outperformed the PDS due to its unsymmetrical structure. Under optimal conditions, the initial pH of the aqueous solution, the US frequency and power, the CuFe2O4 loading, the PMS concentration, and the ATL concentration were also obtained by 7.5, 80 kHz, 100 W, 0.4 g/L, 1.2 mM, and 0.5 mg/L, respectively. At the concentration of 10 mg/L of the ATL, its removal and the mineralisation rates were equal to 83.1% and 48.31%, respectively. The inhibitory effect of the inorganic anions on the removal of the ATL correspondingly followed the sequence of HCO3−>H2PO4−>SO42->NO3−. In the scavenging experiment, methanol showed greater effectiveness compared with other agents in the removal of the ATL, indicating that the SO4•- radicals were the dominant active species within the reaction. The reusability test also demonstrated that the CuFe2O4 efficiency decreased by almost 10% after five consecutive cycles. Besides, the intermediates of the ATL degradation were determined by the liquid chromatography-mass spectrometry (LC-MS) technique and the proposed mechanism for the ATL degradation was expressed. In general, the findings suggested that the US/PMS/CuFe2O4 process had a high synergistic index (SI) and could be effective in removing ATL from aqueous solutions. [ABSTRACT FROM AUTHOR]

The presence of antibiotics and their metabolites such as ciprofloxacin (CIP) in water resources attracted notable attention as a new international health concern. A systematic and review-meta analysis was performed to evaluate the concentration of CIP in the rivers along with the related ecological risk assessment. PubMed, Scopus and Embase databases were screened to retrieve the related articles among 1 January 1983 to 10 July 2018. Fifty-five articles (58 studies of data reports) comprising 1,886 samples from 20 countries were included. Furthermore, the meta-analysis was performed by the aid of a random effects model (REM) to estimate pooled concentration with 95% confidence intervals (CI). According to findings, the concentration of CIP in the river downstream of untreated wastewater was higher than other rivers located downstream of treated wastewater. Also, the meta-analysis of data based on year of study subgroup demonstrated that over time, the concentration of CIP in the rivers was increased. The ecological risk assessment showed that people settled in some regions of South Africa was at a potential (HQ: 1–10 value) adverse ecological risk of CIP in the river. Therefore immediate control plans besides appropriate removal techniques should be approached for complete eradication of antibiotics like CIP. [ABSTRACT FROM AUTHOR]

O3 assisted by solar UV as an integrated treatment of groundwater under visible UV to reach sustainable development were traced. The experimental parameters were set up throughout standard methods and analysis protocols. The best performance of citrus coal was observed at a reaction time of 90 min, pH: 6.5, adsorption bed height = 40 cm, initial OCPs concentration, respectively, as 100 μg/L for alachlor (ALC), α (±)-BHC, atrazine (ATZ), and α-chlordane, 150 μg/L for methoxychlor, 50 μg/L for heptachlor, and 90 μg/L for dieldrin. The best performance of citrus coal was observed at a reaction time of 90 min, pH: 6.5, adsorption bed height 40 cm, initial OCPs concentration of 100 μg/L for ALC, α (±)-BHC, ATZ, and α-chlordane, 150 μg/L for methoxychlor, 50 μg/L for heptachlor, and 90 μg/L for dieldrin. Under the above-mentioned operating conditions, the removal rates were estimated at more than 75% for all these compounds. The adsorption outputs were fitted to the Freundlich model with the average R2 > 0.97, while for the Langmuir model this value was >0.86. Thereby, it is concluded that OCPs adsorption occurs on a heterogeneous surface by multilayer sorption. With regard to Kf(1/n) parameter, for the Freundlich adsorption model, the order of OCPs adsorption was appeared to be methoxychlor > dieldrin > heptachlor > α-chlordane > ALC > α (±)-BHC > ATZ. The optimum variables for UV/O3 were obtained as 0.4 mg/L ozone, pH = 9, and 35 min reaction time, so that, more than 98% of these substances were degraded from the solution under this condition. The reaction kinetics were fitted with R2 value of more than 0.9 for most OCPs. The kinetic reaction constants (k) in pH values of 7 and 9.5 were higher than other ranges for all OCPs. The progress of pH at the alkaline area improved the pseudo-first-order constants. The kinetic model indicated that the reaction rates will be restricted by the initial pH value and the concentration of OH•. This evidence was well-established by monitoring dissolved O2 at the various pH ranges during the experiment runs. Eight intermediates were detected by gas chromatography-tandem mass spectrometry detection with chemical formula as C14H20ClNO3, C13H16ClNO3, C14H18ClNO4, -NHCH(CH3)2, -NHCOCH3, -NH2, C13H9ClO, and C7H5ClO from the samples taken in the non-optimized UV/O3 effluent. However, all of them disappeared in the final effluent at the optimized condition. Altogether, this integrated strategy helped to remove OCPs more than 86% on average, with residues less than 1 μg/L and even 0.05 μg/L in some cases. Due to the generation of a large amount of citrus wastes (46,000 ton/y) in the north of Iran and the abundance of solar energy especially solar UV in the middle east, this hybrid approach to treat groundwater contaminated with agricultural OCPs as a type of EDCs can be an effective alternative for conventional and current removal strategies to provide safety and treat groundwater by this agricultural compound. [ABSTRACT FROM AUTHOR]