Study on diazinon toxicity reduction by electro-Fenton process: A bioassay using daphnia magna.

The realm of diazinon reduction from polluted water has witnessed a surge in the significance of advanced oxidation processes (AOPs) in recent times. However, there is a dearth of research focusing on the mitigation of its toxicity through AOPs. Thus, the primary objective of this study was to evaluate the effectiveness of the Electro-Fenton process (EFP) in the eradication and detoxification of diazinon in aqueous solutions. Synthetic wastewater samples with concentrations of 2, 2.5 and 3 mg/L were prepared. A total of 27 samples were determined using Box Behnken Design. Reaction time, pH and iron to hydrogen peroxide ratio (Fe2+/H2O2) were examined as operational parameters under a constant current of 5.4 amps. The quantification of diazinon concentration was performed using High-Performance Liquid Chromatography (HPLC). To evaluate the detoxification of diazinon, the Daphnia magna bioassay was employed as a methodology in this study. According to the results, the EFP could reduce the diazinon to zero and the LC50 values are increased by applying the process. The LC50 values for diazinon were determined using the Daphnia magna bioassay, considering initial concentrations of 2, 2.5, and 3 mg/L at a pH of 5, a reaction time of 15 min, and an iron to hydrogen peroxide molar ratio of 2. The recorded LC50 values were 3.039, 3.076, and 3.106, respectively, indicating the lowest frequency of cumulative death in Daphnia magna. In this case, after 96 h, only 3 cases (30%) of Daphnia magna death were observed. However, for all the mentioned concentrations of diazinon, after 96 h of exposure to samples without applying the Daphnia Magna death process, it was observed between 60 and 100%. Reducing the diazinon concentration and increasing the 96-h LC50 showed that the EFP can reduce the toxicity of diazinon on Daphnia Magna at the same time. Therefore, EFP can be considered a superior method with low ecotoxicity.

Study of changes in the aging process, microstructure, and mechanical properties of AA2024-AA1050 nanocomposites created by the accumulative roll bonding process, with the addition of 0.005 vol.% of alumina nanoparticles.

We created AA2024-AA1050 and AA2024-AA1050/0.005 vol.% Al2O3 nanocomposites by six accumulative roll bonding (ARB) process cycles. We used AA2024 and AA1050 sheets with a thickness of 0.7 mm and plate-shaped alumina nanoparticles to create a composite. The two AA1050 and one AA2024 sheets (among the two AA1050 sheets) were ARB-ed up to six cycles with and without adding alumina nanoparticles. Also, a sample of the AA1050 without composite making was ARB-ed up to six cycles. We aged some composites after the ARB process in the furnace at 110, 150, and 190 °C. This project performed SEM, TEM, and EDS-MAP analyses, tensile strength, microhardness, and Pin-on-Disc tests to study the ARB-ed sheets. The results of the tensile tests showed that the tensile strength of AA2024-AA1050 created by the six cycles ARB process was two times more than primary AA1050. Also, the wear resistance of this composite was 74% more than six cycles ARB-ed the AA1050. Using 0.005 vol.% alumina nanoparticles in AA2024-AA1050 composite improved its wear resistance by 30%. In the following, the aging process caused an improvement in tensile strength and total elongation of AA2024-AA1050/Al2O3 nanocomposites.

SARS-CoV-2 helicase might interfere with cellular nonsense-mediated RNA decay: insights from a bioinformatics study.

BACKGROUND: Viruses employ diverse strategies to interfere with host defense mechanisms, including the production of proteins that mimic or resemble host proteins. This study aimed to analyze the similarities between SARS-CoV-2 and human proteins, investigate their impact on virus-host interactions, and elucidate underlying mechanisms. RESULTS: Comparing the proteins of SARS-CoV-2 with human and mammalian proteins revealed sequence and structural similarities between viral helicase with human UPF1. The latter is a protein that is involved in nonsense-mediated RNA decay (NMD), an mRNA surveillance pathway which also acts as a cellular defense mechanism against viruses. Protein sequence similarities were also observed between viral nsp3 and human Poly ADP-ribose polymerase (PARP) family of proteins. Gene set enrichment analysis on transcriptomic data derived from SARS-CoV-2 positive samples illustrated the enrichment of genes belonging to the NMD pathway compared with control samples. Moreover, comparing transcriptomic data from SARS-CoV-2-infected samples with transcriptomic data derived from UPF1 knockdown cells demonstrated a significant overlap between datasets. CONCLUSIONS: These findings suggest that helicase/UPF1 sequence and structural similarity might have the ability to interfere with the NMD pathway with pathogenic and immunological implications.

Implemented indoor airborne transmission mitigation strategies during COVID-19: a systematic review.

The COVID-19 pandemic has inflicted major economic and health burdens across the world. On the other hand, the potential airborne transmission of SARS-COV-2 via air can deeply undermine the effectiveness of countermeasures against spreading the disease. Therefore, there is an intense focus to look for ways to mitigate the COVID-19 spread within various indoor settings. This work systematically reviewed articles regarding airborne transmission of SARS-COV2 in various indoor settings since the onset of the pandemic. The systematic search was performed in Scopus, Web of Science, and PubMed databases and has returned 19 original articles carefully screened with regard to inclusion and exclusion criteria. The results showed that the facilities, such as dormitories and classrooms, received the most attention followed by office buildings, healthcare facilities, residential buildings, and other potential enclosed spaces such as a metro wagon. Besides, the majority of the studies were conducted experimentally while other studies were done using computer simulations. United States (n = 5), Spain (n = 4) and China (n = 3) were the top three countries based on the number of performed research. Ventilation rate was the most influential parameter in controlling the infection spread. CO2 was the primary reference for viral spread in the buildings. The use of natural ventilation or a combination of mechanical and natural ventilations was found to be highly effective in the studies. The current work helps in furthering research on effective interventions to improve indoor air quality and control the spread of COVID-19 and other respiratory diseases. Supplementary information: The online version contains supplementary material available at 10.1007/s40201-023-00847-0.

Pathological effects of SARS-CoV-2 on hematological and immunological cells: Alterations in count, morphology, and function.

The novel Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19 outbreak, spread rapidly and infected more than 140 million people with more than three million victims worldwide. The SARS-CoV-2 causes destructive changes in the immunological and hematological system of the host. These alterations appear to play a critical role in disease pathology and the emerging of clinical manifestations. In this review, we aimed to discuss the effect of COVID-19 on the count, function and morphology of immune and blood cells and the role of these changes in the pathophysiology of the disease. Knowledge of these changes may help with better management and treatment of COVID-19 patients.

Urinary level of heavy metals in people working in smoking cafés.

Previous researches have reported significant levels of heavy metals in indoor air of smoking cafés. The current research aimed to evaluate the potential exposure of smoking cafés workers to heavy metals through quantifying amounts of these pollutants in urine samples. To this end, 35 waterpipe/cigarette cafés workers were selected as the exposed population, 35 employees from non-smoking cafe' as the control group 1 (CG1) and 25 cases of the normal citizens as the control group 2 (CG2); and their urine samples were taken. Samples were then prepared by acid digestion approach and measured by the ICP in order to determine amount of heavy metals in them. The findings of the current work show the significant difference among urinary levels of metals in the exposed and both CG1 and CG2 (P value < 0.05). Furthermore, urinary metal levels in samples collected from smoking café workers after the exposure were considerably higher than those were collected before the exposure (P-value <0.05). According to the findings, "tobacco type" could be considered as a leading factor for heavy metal exposure in studied smokers. Additionally, a positive and significant association was found between urinary metals and urinary levels of 8-OHdG (a markers of DNA degradation through oxidative stress). Therefore, workers in waterpipe/cigarette café can be classified as high risk people in terms of DNA oxidative damage.

Accumulation and human health risk assessment of nitrate in vegetables irrigated with different irrigation water sources- transfer evaluation of nitrate from soil to vegetables.

The present study aimed to investigate the rate of accumulation, human health risk assessment, and nitrate-related transfer factor in vegetables irrigated with different sources, including treated wastewater effluent (TWE) of Kermanshah wastewater treatment plant, Gharasoo river water (RW) of Kermanshah, and well water with chemical fertilizer (WWF). For this purpose, three different types of vegetables, including basil, coriander, and radish, was cultivated, and each of them was irrigated by the three irrigation sources mentioned above. Finally, the amount of nitrate in different sources of irrigation, soil (before growing vegetables and after harvesting vegetables), and the mentioned vegetables was measured. Based on the study results, it can be concluded that the water of the Gharasoo River (RW), compared to the other two irrigation sources, causes more nitrate accumulation in the soil and vegetables grown in it. The highest transmission factor was related to basil vegetables irrigated with WWF. The results showed that the average daily intake of nitrate through the consumption of vegetables grown in Kermanshah with any irrigation water is less than the allowable amount, so the consumption of such vegetables is not dangerous to consumers' health. Therefore, it is suggested that the best irrigation source for vegetable cultivation in Kermanshah is TWE, provided that all of its physical, chemical and microbial parameters meet the standards for reuse in agriculture irrigation. Thus, the use of treated wastewater reduces the need for farmers to use chemical and organic fertilizers and cost-effectiveness, high frequency, and high availability.

SARS-CoV-2 spike protein displays sequence similarities with paramyxovirus surface proteins; a bioinformatics study.

Recent emergence of SARS-CoV-2 and associated COVID-19 pandemic have posed a great challenge for the scientific community. In this study, we performed bioinformatic analyses on SARS-CoV-2 protein sequences, trying to unravel potential molecular similarities between this newly emerged pathogen with non-coronavirus ssRNA viruses. Comparing the proteins of SARS-CoV-2 with non-coronavirus positive and negative strand ssRNA viruses revealed multiple sequence similarities between SARS-CoV-2 and non-coronaviruses, including similarities between RNA-dependent RNA-polymerases and helicases (two highly-conserved proteins). We also observed similarities between SARS-CoV-2 surface (i.e. spike) protein with paramyxovirus fusion proteins. This similarity was restricted to a segment of spike protein S2 subunit which is involved in cell fusion. We next analyzed spike proteins from SARS-CoV-2 "variants of concern" (VOCs) and "variants of interests" (VOIs) and found that some of these variants show considerably higher spike-fusion similarity with paramyxoviruses. The 'spike-fusion' similarity was also observed for some pathogenic coronaviruses other than SARS-CoV-2. Epitope analysis using experimentally verified data deposited in Immune Epitope Database (IEDB) revealed that several B cell epitopes as well as T cell and MHC binding epitopes map within the spike-fusion similarity region. These data indicate that there might be a degree of convergent evolution between SARS-CoV-2 and paramyxovirus surface proteins which could be of pathogenic and immunological importance.

Global Prevalence of Yersinia enterocolitica in Cases of Gastroenteritis: A Systematic Review and Meta-Analysis.

The prevalence of Yersinia enterocolitica in gastroenteritis is often underestimated. It relates considerably to morbidity and medical expenses around the world. Understanding the cause of gastroenteritis leads to making the appropriate treatment decisions. We systematically searched PubMed, Science Direct, Embase, and Scopus to identify all published studies between Jan. 1, 2000, and Dec. 31, 2019, to assess the prevalence of Y. enterocolitica in gastroenteritis patients. A total of 5039 articles were identified that lead to the extraction of data from 47 of them. The pooled prevalence of Y. enterocolitica in cases of gastroenteritis was estimated as 1.97% (1.32-2.74%) in the culture method and 2.41% (1.07-4.22%) in the molecular method. Among the biotypes of Y. enterocolitica, 1A (62.48%) and 1B (2.14%) had the most and least prevalence, respectively. Serotype O3 Y. enterocolitica with 39.46% had the highest and O5,27 with 0.0% had the least prevalence in gastroenteritis cases. In conclusion, the findings of this systematic review show that Y. enterocolitica is prevalent in gastroenteritis in all age groups. Serotypes O3 and O9 of Y. enterocolitica had the highest prevalence and O5,27 had the least prevalence in diarrheal patients. The prevalence of Y. enterocolitica was similar in both gender and different seasons. It should be noted that to determine the role of the organism, more studies are needed especially in food-borne diseases.

Occurrence, potential sources, in vitro bioaccessibility and health risk assessment of heavy metal in indoor dust from different microenvironment of Bushehr, Iran.

Indoor dust samples were collected from 42 microenvironments of residential buildings (RB, 15 samples), official buildings (OB, 10 samples), laboratory rooms (LR, 7 samples), and school classroom (SCR, 10 samples) in Bushehr, whereby the concentration of zinc, copper, lead, cadmium, nickel, and chromium was studied. The results of this study indicated that the mean concentrations of Zn, Cu, Pb, Cd, Cr, and Ni in the indoor dust samples were 567.18, 186.09, 209.01, 5.31, 143.20, and 57.09 mg/kg in RB, 1077.34, 539.67, 274.89, 8.12, 155.30, and 92.55 mg/kg in OB, 246.40, 149.56, 127.2, 1.96, 43.45, and 91.09 mg/kg in LR and 271.43, 189.84, 164.44, 3.06, 124.20, and 70.09 mg/kg in SCR. The results of principal cluster analysis showed that the heavy metals in indoor environments were mostly originated from smoking tobacco and cigarette, traffic sources, old building materials, and building paint colors. The results of this study also revealed that the concentration of heavy metals in indoor dust had a negative and significant relationship (P value < 0.05 in most cases) with rate of ventilation, and a positive and significant relationship with smoking inside buildings (P value < 0.05 in most cases). The bioaccessibility for zinc, copper, lead, cadmium, nickel, and chromium was 69.12, 40.08, 43.33, 79.81, 31.10, and 6.31%, respectively, in indoor dust. Further, risk assessment showed that the risk values of carcinogenicity and non-carcinogenicity resulting from heavy metals inside the studied microenvironments had exceeded the recommended safe limit by EPA. In terms of potential ecological risks, it was found that heavy metals in these microenvironments have exceeded the hazardous ecological levels presented by different indices and can have considerable negative ecological effects. Thus, it is essential that further and better studies and monitoring be performed on these environments, and suitable control recommendations and solutions should be regulated for this public health threat.

A machine learning approach to estimation of phase diagrams for three-component lipid mixtures.

The plasma membrane of eukaryotic cells is commonly believed to contain ordered lipid domains. The interest in understanding the origin of such domains has led to extensive studies on the phase behavior of mixed lipid systems. Three-component phase diagrams, composed of a high melting temperature (Tm) lipid, cholesterol, and a low Tm lipid have been valuable in studying lipid phase behavior. However, developing phase diagrams over the entire composition space and with precise tie-lines requires significant experimental effort. In this study, a machine learning approach was used to predict the Tm of lipids and generate phase diagrams from lipid mixtures. First, artificial neural network (ANN) was used for the prediction of Tm. The network was trained using available Tm data and was able to generate Tm values that closely matched literature results for its testing dataset. This model was then used to predict the Tm for lipids that have not yet been experimentally tested. Then, random forests (RF) and support vector machines (SVM) were trained and tested for their ability to predict a test three-component phase diagram. The model from the RF algorithm was able to generate a diagram that closely matched published results. This model was then used to generate phase diagrams for lipid mixtures at various temperatures and various degrees of unsaturation. This machine learning approach to the generation of lipid phase diagrams has the potential to save significant time and resources in studies of lipid phase behavior.

Ecological and health risk assessment of exposure to atmospheric heavy metals.

In the present study, we assessed the concentration of airborne HMs (Zn, Cu, Pb, and Cd) and their probable sources using the bark of Pinus eldarica as a bio-indicator. Hence, 47 tree bark samples were harvested according to the land uses and biomonitoring techniques in the city of Yazd, Iran. The potential health risks in 13 age groups, ecological risk, as well as the possible relationship between HM concentrations and traffic indicators, were evaluated. The order of average HM concentrations in the P. eldarica bark samples was as Zn > Pb > Cu > Cd. The mean values of non-carcinogenic risks of all HMs in entire age groups were within secure range (HQ < 1); however, the carcinogenic risk of Cd was higher than the allowed level (TCR > 1 × 10-6). About Pb, it was in the safe level. The main element causing potential ecological risks was Cd, indicating moderate to very high ecological risk in most of the study areas. There was an inverse significant association between distance from major roads and Pb concentration (ß = -0.011 95% confidence interval (CI): 0.022, -0.0001). All HMs in bark samples render the negative Moran's index, representing a random spatial distribution pattern. Besides, according to principal component analysis (PCA), the first component accounted for 36.55% of the total variance, dominated by Cd, Pb, Cu, and Zn, respectively, and characterized by vehicle and industrial emissions. Our results infer that industrial activities and traffic are the main sources of HMs pollution in urban environments that should be considered by decision-makers.

Dynamic assessment of economic and environmental performance index and generation, composition, environmental and human health risks of hospital solid waste in developing countries; A state of the art of review.

Many studies have been conducted on hospital solid waste management (HSWM) throughout the world, especially developing countries. This interdisciplinary study aims to summarize the available knowledge on the health and environmental risks of hospital solid waste (HSW) and also, develop a dynamic associational assessment among hospital solid waste generation rate (HSWGR), hospital solid waste composition (HSWC), gross domestic product (GDP) per capita, and environmental performance index (EPI) in some developing countries for the first time. The results of this study showed that researchers from India, China, Pakistan, Brazil, and Iran had found more evidence about the health, economic, and environmental issues in HSW than the other developing countries. The literature showed that the highest and lowest reported HSWGR (in national average level) belonged to Ethiopia (6.03) and India (0.24) kg bed -1 day-1, respectively. It has also been shown that all studied countries except Serbia, have higher levels of hazardous waste in their HSWC, based on the WHO's standard. Furthermore, the quantity and quality of HSW in developing countries depend on the service provided by the hospital, type of hospital, HSWM system, and the level of regional economic and culture. The association analysis showed that the EPI and GDP per capita of developing countries were significantly (p-value <0.05) associated with HSWGR, non-hazardous HSW, and hazardous HSW by the Spearman coefficients equal to 0.389, 0.118, -0.118, and 0.122, 0.216, and -0.346, respectively. However, it can be concluded that GDP per capita and EPI have a weak correlation with hazardous HSW and non-hazardous HSW. Moreover, HSW has many hazardous health and environmental risks such as dioxin and furan, that must be controlled and managed through implementing programs and policies based on sustainable development. As a final point, we believed that the present study can be considered to be a guide for future studies on HSWM in developing countries.

Inventory management of surgical supplies and sterile instruments in hospitals: a literature review.

Operating rooms are considered a significant revenue source, as well as the main source of waste and cost, among the hospital's departments. Any cost savings in operating rooms will have a broad financial impact. Over the last decades, many researchers and practitioners have conducted studies to deal with the issue of managing surgical supplies and instruments, which are highly affected by surgeons' preferences. The purpose of this article is to present an up-to-date review of research in the field of inventory management of surgical supplies and instruments. We have analysed the literature in a systematic manner and organised the identified papers into two groups: the papers that were published by scientific researchers and developed optimisation techniques and the papers that were published by practitioners and reported their observations of the current issues in the operating room. We also identify the future research directions leading to operating room inventory cost reduction.

Degradation of dimethyl phthalate using persulfate activated by UV and ferrous ions: optimizing operational parameters mechanism and pathway.

The present study aimed to model and optimize the dimethyl phthalate (DMP) degradation from aqueous solution using UVC/ Na2S2O8/Fe2+ system based on the response surface methodology (RSM). A high removal efficiency (97%) and TOC reduction (64.2%) were obtained under optimum conditions i.e. contact time = 90 min, SPS concentration = 0.601 mM/L, Fe2+ = 0.075 mM/L, pH = 11 and DMP concentration = 5 mg/L. Quenching experiments confirmed that sulfate radicals were predominant radical species for DMP degradation. The effect of CO3 - on DMP degradation was more complicated than other aquatic background anions. The possible pathway for DMP decomposition was proposed according to HPLC and GC-MS analysis. The average oxidation state (AOS) and carbon oxidation state (COS) values as biodegradability indicators demonstrated that the UVC/SPS/Fe2+ system can improve the bioavailability of DMP over the time. Finally, the performance of UVC/SPS/Fe2+ system for DMP treatment in different aquatic solutions: tap water, surface runoff, treated and raw wastewater were found to be 95.7, 88.5, 80.5, and 56.4%, respectively. Graphical abstract.

Arash: A social robot buddy to support children with cancer in a hospital environment.

This article presents the thorough design procedure, specifications, and performance of a mobile social robot friend Arash for educational and therapeutic involvement of children with cancer based on their interests and needs. Our research focuses on employing Arash in a pediatric hospital environment to entertain, assist, and educate children with cancer who suffer from physical pain caused by both the disease and its treatment process. Since cancer treatment causes emotional distress, which can reduce the efficiency of medications, using social robots to interact with children with cancer in a hospital environment could decrease this distress, thereby improving the effectiveness of their treatment. Arash is a 15 degree-of-freedom low-cost humanoid mobile robot buddy, carefully designed with appropriate measures and developed to interact with children ages 5-12 years old. The robot has five physical subsystems: the head, arms, torso, waist, and mobile-platform. The robot's final appearance is a significant novel concept; since it was selected based on a survey taken from 50 children with chronic diseases at three pediatric hospitals in Tehran, Iran. Founded on these measures and desires, Arash was designed, built, improved, and enhanced to operate successfully in pediatric cancer hospitals. Two experiments were devised to evaluate the children's level of acceptance and involvement with the robot, assess their feelings about it, and measure how much the robot was similar to the favored conceptual sketch. Both experiments were conducted in the form of storytelling and appearance/performance evaluations. The obtained results confirm high engagement and interest of pediatric cancer patients with the constructed robot.

De-Esterified Tragacanth Microspheres Loaded into Eudragit S-100 Coated Capsules for Colon-Targeted Delivery.

The objective of this study was to develop a novel bacterially-triggered micro-particular system of de-esterified tragacanth (DET) in combination with Eudragit S-100 coated capsules for colon drug delivery of 5-fluorouracil (5-FU) using microemulsion method. The loading study was conducted at different drug-to-polymer ratios and cross-linker concentrations. The maximum loading efficiency was achieved, 44.1% at 1:5 drug-to-polymer ratio and 0.7% cross-linker concentration. The FTIR results also confirmed the encapsulation of 5-FU in microspheres. The release profile was dependent on the cross-linker concentration, environmental pH, and presence of pectinase enzyme. Microspheres inserted into Eudragit S-100 coated capsules released less than 5% of the drug at stomach and small intestine pH levels, whereas 70% of the drug was released at colon pH levels, and about 25% of the drug did not release unless in the presence of pectinase enzyme. To omit burst release, microspheres were washed with water, and the release became pH independent, and was just achieved in the presence of pectinase enzyme. 5-FU loaded microspheres with an IC50 value of 80 µg/mL were as effective as the free drug on HT-29. Generally, the results demonstrated that drug-loaded microspheres inserted into Eudragit S-100 coated capsules can be effective for colon-targeted delivery.

A comparative study of the disinfection efficacy of H2O2/ferrate and UV/H2O2/ferrate processes on inactivation of Bacillus subtilis spores by response surface methodology for modeling and optimization.

Although chlorination can inactivate most of the microorganisms in water but protozoan parasites like C. parvum oocysts and Giardia cysts can resist against it. Therefore, many researches have been conducted to find a novel method for water disinfection. Present study evaluated the synergistic effect of H2O2 and ferrate followed by UV radiation to inactivate Bacillus subtilis spores as surrogate microorganisms. Response surface methodology(RSM) was employed for the optimization for UV/H2O2/ferrate and H2O2/ferrate processes. By using central composite design(CCD), the effect of three main parameters including time, hydrogen peroxide, and ferrate concentrations was examined on process performance. The results showed that the combination of UV, H2O2 and ferrate was the most effective disinfection process in compare with when H2O2 and ferrate were used. This study indicated that by UV/H2O2/ferrate, about 5.2 log reductions of B. subtilis spores was inactivated at 9299 mg/l of H2O2 and 0.4 mg/l of ferrate concentrations after 57 min of contact time which was the optimum condition, but H2O2/ferrate can inactivate B. subtilis spores about 4.7 logs compare to the other process. Therefore, the results of this research demonstrated that UV/H2O2 /ferrate process is a promising process for spore inactivation and water disinfection.

Response surface methodology as a tool for modeling and optimization of Bacillus subtilis spores inactivation by UV/ nano-Fe0 process for safe water production.

One of the most important aspects of environmental issues is the demand for clean and safe water. Meanwhile, disinfection process is one of the most important steps in safe water production. The present study aims at estimating the performance of UV, nano Zero-Valent Iron particles (nZVI, nano-Fe0), and UV treatment with the addition of nZVI (combined process) for Bacillus subtilis spores inactivation. Effects of different factors on inactivation including contact time, initial nZVI concentration, UV irradiance and various aerations conditions were investigated. Response surface methodology, based on a five-level, two variable central composite design, was used to optimize target microorganism reduction and the experimental parameters. The results indicated that the disinfection time had the greatest positive impact on disinfection ability among the different selected independent variables. According to the results, it can be concluded that microbial reduction by UV alone was more effective than nZVI while the combined UV/nZVI process demonstrated the maximum log reduction. The optimum reduction of about 4 logs was observed at 491 mg/L of nZVI and 60 min of contact time when spores were exposed to UV radiation under deaerated condition. Therefore, UV/nZVI process can be suggested as a reliable method for Bacillus subtilis spores inactivation.

Characteristics, distribution and sources of polychlorinated biphenyls (PCBs) in coastal sediments from the heavily industrialized area of Asalouyeh, Iran.

In this research, the levels of polychlorinated biphenyls (PCBs) were investigated in the marine sediments of Asaluyeh harbor, in the Persian Gulf. The samples were taken from industrial, semi-industrial and urban regions. The mean concentration levels of total (Σ) 18 detected PCBs were 514.32, 144.67 and 31.6 pg/g dw for the industrial, semi-industrial and urban sampling stations, respectively. Based on a multivariate statistical analysis, it was found that high contamination levels of PCBs in sediments collected along the Persian Gulf were associated with releases from local industries. Total organic carbon (TOC) content was significantly and positively correlated with the concentrations of PCB congeners. World Health Organization toxic equivalents (TEQs) for PCBs ranged from 0.04 to 2.66 pg TEQ/g dry weight (dw) in the coastal sediments. The TEQ values in this study were higher than many reported worldwide in the literature for sediments. This suggests that there are high levels of contamination in the area due to industrial and other human activities.