Ultrasound‒induced facile synthesis of spinel CoFe2O4‒PAC magnetic nanocatalyst for remediation of hypersaline petrochemical wastewater: Degradation mechanism, biodegradability enhancement and phytotoxicity mitigation.

In this study, magnetic CoFe2O4-PAC nanocatalysts were synthesized through facile hydrothermal and co‒precipitation approaches with ultrasonic irradiation, which were used for the treatment of hypersaline petrochemical wastewater (HPCW). When an ultrasound‒induced synthesis process (US@CoFe2O4‒PAC) was used, a more efficient and stable magnetic spinel CoFe2O4‒PAC nanocatalyst was developed. The application of this nanocatalyst as a PMS activator, not only caused eradication of 90.4% of chemical oxygen demand (COD) of a HPCW after 90 min reaction time under the optimum conditions (pH 5-6, catalyst dose 1.0 g/L and 1.0 mM PMS), but also led to marginal leaching of iron (314 µg/L) and cobalt (95 µg/L) from the nanocatalyst. Recycling experiments over five consecutive runs showed a negligible decrease (7.2%) in COD removal efficiency which proved the stability and reusability of magnetic US@CoFe2O4-PAC. Two main mechanisms of adsorption and catalytic oxidation processes (homogeneous and heterogeneous PMS) are involved simultaneously in the PMS/US@CoFe2O4-PAC system, which are responsible for the destruction of refractory contaminants of HPCW through the generation of SO4•‒ and OH• radicals. COD of HPCW was mainly removed through SO4•- radical attack (73.6%) and the biodegradability of HPCW was enhanced dramatically after 90 min reaction time. The germination index (GI) of raw HPCW was increased 17.1 ± 4.2% and 24.3 ± 8.8% after 15 and 90 min reaction time, respectively, even PMS/US@CoFe2O4-PAC system showed less impact on phytotoxicity mitigation. Hence, it can be recommended to dilute the effluent before using for irrigational purpose. The findings of this study present practical significance of spinel US@CoFe2O4-PAC, which is an environment‒friendly catalyst, easy to handle and can sustain long‒term operation for the treatment of recalcitrant hypersaline wastewater and the other potential practical applications.

The concentration of phthalates in drinking water in Iran: A systematic review and meta-analysis.

PAE and PC polymers, such as BPA, are utilized to make water bottles. Due to the lack of polymer-chemical interaction, PAE can enter drinking bottles during production, wrapping, and keeping. Phthalates can transfer from the bottle to the water depending on keeping conditions (temperature, time, sunlight intensity), pH, and bottle capacity. Since there haven't been previous studies published on the subject, the aim of this meta-analysis and systematic review research is to determine the level of phthalates in drinking water consumed in Iranian cities. Web of Science, Science of Direct, Scopus, and PubMed, databases have been used in this study. Eight studies were selected from 556 initial publications after screening for duplication and irrelevant information. Articles from January 1, 2000, to February 10, 2024, were found in the mentioned databases. Among the types of phthalates, the concentration of DEHP was reported higher than the others Because its concentration has been reported in seven out of eight studies. The highest concentration of DEHP was reported by Mehraie(2.22 µg/l), Zare Jeddi (0.8 µg/l), Yousefi (0.77 µg/l), Abtahi (0.76 µg/l), Zare Jeddi (0.42 µg/l), Abdolahnejad(0.15 µg/l), and Pourzamani (0.08 µg/l). The highest concentration of DEP, DBP, BBP, and PA was reported by Abtahi (0.77 µg/l) and Esteki (2.25 µg/l), Mehraie(0.93 µg/l), and Pourzamani (0.83 µg/l). The results of this study showed that the most important phthalates measured in drinking water include DEP, DEHP, DBP, BBP, and PA. According to the results of the present studies, the most important factor in the increase of phthalates is the storage conditions of drinking water (temperature, sunlight, and the type of pipe or bottle).

Distribution of total petroleum hydrocarbons in superficial sediments of Karun River Basin, southwest of Iran: spatial and seasonal variations, source identification, and ecological risk.

Total petroleum hydrocarbons (TPHs) are common environmental pollutants in aquatic ecosystems that tend to adsorb onto the sediments. This study aimed to monitor the concentration and assessment of contamination level of TPHs in the sediments of Karun River and Bahmanshir estuary, which will eventually flow into the Persian Gulf. GIS-mapping technique was used to indicate the distribution of TPHs. The samples were collected during dry and wet seasons at 15 monitoring stations. - The maximum amount of TPHs was obtained at station No. 14 in the dry season (225.29 µg/g). The indices of determining the pollution source showed that hydrocarbons in polluted areas were mainly of biogenic origin. Compared to sediment quality guidelines (SQGs) and contamination factor (Cf), the study area sediments were in the conditions of moderate pollution and had a low ecological risk.

Analysis of heavy metals and PAHs in the waste resulting from hookah consumption: Ahvaz City, Iran.

Hookah, a popular form of smoking tobacco, has been commonly used in Asia and Africa. However, the widespread consumption of hookah has a major impact on human health being. In addition to health risks, discarding the waste products of hookah would be a serious potential danger for environmental resources. In this study, the waste materials of hookah consumption (water, tobacco, and charcoal) were analyzed for the determination of the metals and PAHs using inductively coupled plasma mass spectrometry (ICP-MS) and gas chromatography-mass spectrometry (GC-MS), respectively. Results showed that the average concentration of iron in different flavors of tobacco had the highest amount (3654.2 ppb). Iron had the maximum concentration among the heavy metals, particularly in the mint flavor (10,863.3 ± 4.1). The highest Æ©PAHs were related to the mint flavor (47.48 ± 15.21 ppb). Results showed that the aromatic tobacco available in the Ahvaz-Iran market is polluted by heavy metals. The high consumption of hookah in Ahvaz city and the presence of pollutants in hookah waste materials, apart from health risk aspects, can be potentially regarded as sources of environmental contamination. Therefore, education and preventive measures are necessary for this concern.

Sonochemical degradation of bisphenol A using persulfate activated by hematite nanoparticles.

In this study, hematite nanoparticles (HNPs) were used as the persulfate (PS) activator for the sonocatalytic degradation of bisphenol A (BPA). The physicochemical properties of the synthesized HNPs were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The effect of different operational parameters (pH, nanoparticle dosage, persulfate concentration, and ultrasonic power) on catalytic activity were evaluated. The BPA degradation rate was improved when ultrasonic (US) irradiation was used simultaneously with HNPs for activating PS. According to the results, 98.94% of BPA (10 mg/L) was degraded within 15 min of reaction time at 4 mM persulfate and 0.01 g/L HNPs under ultrasonic irradiation of 250 W. The degree of mineralization of BPA was measured using chemical oxygen demand (COD), and 36.98% was achieved under optimum conditions. Quenching tests were done using different scavenger compounds; these showed that both hydroxyl and sulfate radicals were reactive species in BPA degradation. According to the results of reusability tests, the degradation efficiency decreased to 86.34%, indicating that HNPs can be recycled several times. All of the anions tested, but mainly hydrogen phosphate, had an inhibitory effect on BPA degradation. The results showed that the US/HNPs/PS process is effective for the degradation of the organic pollutants.

Petroleum Contaminated Seawater Detoxification in Microcosm by Halotolerant Consortium Isolated from Persian Gulf.

Bioremediation of a petroleum contaminated seawater from Persian Gulf was investigated and efficiency of natural attenuation by native halotolerant bacterial consortium, biostimulation by addition of macro nutrients (nitrogen and phosphorus) and surfactant and bioaugmentation by application of halotolerant hydrocarbon degrading strains were evaluated. Biodegradation rates in defined conditions were studied for 30 days. Four pure isolates including Bacillus sp. PG-1, Pseudomonas aeruginosa PG-2, Paenibacillus lautus PG-3, and Pseudomonas putida PG-4 were used to preparation of bacterial consortium. Results indicated that the bioaugmentation yielded the best TPH removal efficiency of 56.24%, followed by biostimulation with surfactant addition (removal of 31.52%). The most bacterial density was also observed for bioaugmentation bioreactor. Toxicity of reaction medium was evaluated by oxygen consumption rate inhibition, dehydrogenase activity inhibition and growth rate inhibition methods in which, the least toxicity rates of 27%, 25% and 31% were observed for bioaugmentation based bioreactor, respectively. Simultaneous bioaugmentation and biostimulation can efficiently reduce the crude oil content in the surface of seawater using halotolerant strains.

Application of electro-Fenton process for treatment of composting plant leachate: kinetics, operational parameters and modeling.

BACKGROUND: Composting plant leachate is considered as one of the highly polluted wastewaters which is necessary to be treated by simple, economic, fast and environmentally compatible methods. In this study, treatment of fresh composting plant leachate by electro-Fenton (EF) process was investigated. METHODS: The effect of various input variables like pH (2-7), DC currents (1.5-3 A), H2O2 concentrations (theoretical ratio H2O2/COD: 0.1-0.6), TDS changes (4-6%), feeding mode, and BOD/COD ratio at the optimal point were studied. The settling characteristics of the waste sludge produced by the treatment (sludge volumes after 30-min sedimentation: V30) were also determined. Artificial neural network (ANN) approach was used for modeling the experimental data. RESULTS: Based on the results, the best removal rate of COD was obtained at pH: 3, 3 A constant DC current value, 0.6 theoretical ratio H2O2/COD and the feeding mode at four step injection. BOD/COD ratio at the optimal point was 0.535 and the maximum COD removal was achieved at TDS = 4%. In the optimal conditions, 85% of COD was removed and BOD/COD ratio was increased from 0.270 to 0.535. The data follow the second-order kinetic (R2 > 0.9) and neural network modeling also provided the accurate prediction for testing data. CONCLUSION: Results showed that EF process can be used efficiently for treatment of composting plant leachate using the proper operating conditions.