Detection to trace aluminum ion of pharmaceutical wastewater using synthesis of Schiff-based chemosensor

Background: The aim of this research was to develop a fluorogenic sensor for Al3+ions, which have been identified as a possible food and drinking water pollutant by the WHO and considered to be harmful to human health. Methods: The sensing mechanism was based on excited-state intramolecular proton transfer, with the intramolecular rotation restriction occurring after binding with the analyte. The probe attaches Al3+selectively and emits strong emission in 4:1 H2 O/MeOH (v/v) solution while irradiated at 400 nm in the presence of a wide number of cations, acting as a "turn-on" fluorescence chemosensor. The range of detection for Al3+is 3.3 nM (3 method), which is more than 200 times more responsive than the WHO suggested limit of 7.4 mM (3σ method). Mass spectra, job plot, and Benesi-Hildebrand plot were used to determine the formation of the 1:1 metal-to-ligand complex. Results: Aluminum (Al) ion content in effluent obtained from the pharmaceutical sector is 0.381 mM, which is a trace amount. A separate in vitro experiment indicates that the probe can precisely perceive Al3+ions in a cell line. The sensor-based method is developed to detect 3.3 nM of Al3+ions, which is significantly less than the WHO max. Conclusion: The probe to detect Al3+ions in live cells. HL becomes a flexible sensor for recognizing intracellular Al3+in human liver cancer cell line Hep G2 and human lung fibroblast cell lines by fluorescence cell imaging procedures, and the probe’s non-toxicity has been proven by MTT tests up to 100M.

Determination and risk assessment of heavy metals in air dust fall particles

Background: Urban and industrial development has increased the concentration of heavy metals in various environments, and also, increased their amount in dust fall particles. The aim of this study was to determine and assess the risk of heavy metals in air dust fall particles. Methods: Sampling of air dust fall particles was performed using the British model Dust Fall Jar devices. Heavy metals concentrations in the samples were determined using an atomic absorption spectrometer device. Then, the risk assessment of heavy metals in air dust fall was calculated by three indicators including enrichment factor (EF), geo-accumulation index (Igeo), and integrated pollution index (IPI). Data were analyzed using descriptive statistics and Excel 2016 software. Results: Zn was the most abundant heavy metal. The results of EF index showed that the highest degree of enrichment of dust fall particles with heavy metals is related to Ag and the lowest one is related to Cr. Also, the changes of Mean of both Igeo and IP indicators were as Ag > Pb > Zn > Cd > Cu > Co > Cr. Conclusion: According to the results, it can be concluded that Cr metal is originated from the earth and other metals are of man-made origin and are mainly due to the emissions of vehicles and industries. Also, on average, the samples had very low pollution in relation to all metals. Although the amount of pollution caused by heavy metals has not exceeded the allowable limits, but considering industrial development programs in the region, continuous measures to control air pollution caused by industries, are absolutely necessary.

Frequency and antibiotic resistance of Helicobacter pullorum among exposed and non-exposed population

Background: Helicobacter pullorum can infect the intestinal tracts of both humans and avian species. This study aimed to assess the frequency and antibiotic resistance of H. pullorum isolated from workers in the poultry slaughterhouses, farms, and markets as exposed population and healthy people who referred to the hospital as non-exposed population by culture method and polymerase chain reaction (PCR) test. Methods: Two hundred healthy individuals, including 100 individuals from exposed population and 100 from non-exposed population were selected in Semnan. Fresh stool samples were examined by conventional culture method and biochemical tests. PCR test with 16S rRNA gene was employed to confirm the H. pullorum isolates. Antibiotic resistance test was done using the disk diffusion method and various antimicrobial agents. Results: Generally, 17 (17%) samples from exposed population and 12 (12%) samples from non-exposed population were H. pullorum positive by culture method and biochemical tests. However, PCR test could confirm 10 (10%) and 7 (7%) samples from exposed and non-exposed populations, respectively. Therefore, the frequency of H. pullorum was determined to be 9.5%. Antibiotic resistance test could reveal that most of the isolates were resistant to ciprofloxacin (84.2%), whereas resistance to colistin and fosfomycin was found to be 15.8%. Conclusion: The present study illustrated that H. pullorum can be present among healthy population with the low frequency rate. Moreover, it was indicated that the frequency of this food-borne pathogen is high in the exposed population. Therefore, there is a high demand for good observation for slaughter hygiene and implementation of routine surveillance in the poultry farms and markets.

Accomplishment of water safety plan using quality assurance tool in 2020-2021: A case study in a western city of Gilan province, Iran

Background: Water safety plan is a systematic approach to ensure the quality of water delivered to consumers from catchment to consumption. Methods: This study was conducted on the groundwater system of Talesh, Gilan, in 2020-2021. A Water Safety Plan (WSP) consists of 5 phases and 12 steps. In the implementation of this plan, all modules were reviewed. Software checklists were prepared and based on the background information in Talesh Water and Wastewater Company, interviews with experts and field visits were performed, and then, entered into WSP QA TOOL software. Results: Out of 440 raw scores, 222 points were obtained, indicating 50.45% compliance with WSP. The description system with the highest score (100%) and the management procedures with the lowest score (50%) were in line with this plan. The stages of development and supporting program and review of WSP cannot be evaluated due to the incomplete implementation of water safety plan in Talesh. Between different parts of the water supply system, more attention has been paid to production sources and points of use. Conclusion: This study identifies the inefficiency in dependence on the final tests and the necessary items in updating the supply system of Talesh. According to the study of the different stages of WSP, the system has a moderate level of safety.

Photocatalytic removal of Malachite green dye from aqueous solutions by nano-composites containing titanium dioxide: A systematic review

Background: Malachite green (MG) is widely used as a fungicide, Bactericide parasiticide in the aquaculture industry, as a food additive, medical disinfectant, and also, as a dye for materials such as silk, leather, paper, etc. In this study, the photocatalytic removal of MG from aqueous solutions using TiO2-containing nanocomposites was reviewed. Methods: In this study, four databases (PubMed, Web of Science, ScienceDirect, and Scopus) were systematically searched to collect studies on the decomposition of MG using nanocomposites containing TiO2 under UV light radiation. Results: In total, 10 related and eligible studies were selected. Based on the results, TiO2 was doped with iron, Sn, Ag, Si, and Ni. The highest percentage of photocatalytic decomposition for MG was observed in Sn > Ni > Ag > Fe > Si. The removal efficiency of MG in the studied papers was between 75%-100%. Conclusion: Recombinant nanocomposites had a higher dye removal percentage than uncombined ones because they play an important role in the photocatalytic process of dye, by producing free radicals.

Advanced oxidation of high concentrations of formaldehyde in aqueous solution under fluorescent and UV light

Background: Formaldehyde (FA) is a carcinogen compound, which is soluble in water. FA can be removed from aqueous solution using advanced oxidation methods. Methods: In this study, the oxidation of FA was studied under fluorescent and UV light. Hydrogen peroxide (H2 O2 ) was used as an oxidant. The pH value and H2 O2 amount of samples were optimized. The chemical oxygen demand (COD), FA concentration, and H2 O2 consumption were followed. Results: It was observed that the pH value of the sample was more significant under fluorescent light than UV light at oxidation of FA. The highest COD removal and H2 O2 reduction were 18.57 and 30.90%, respectively, at pH 12.00, with a 1:1 ratio of FA:H2 O2 under fluorescent light. 86.41% FA and 62.12% COD removal were achieved at pH 7.00, with a 1:2 ratio of FA:H2 O2 , under UV light. It was observed that H2 O2 was consumed at all pH values under UV light. On the other hand, under fluorescent light, the concentration of H2 O2 decreased only at pH 12. In control samples containing only H2 O2 , the H2 O2 reduction was 92.09% at pH 11.91, while it was 2-6% at other pH levels under fluorescent light. The H2 O2 reduction changed between 33 and 44% at different pH values under UV light. The oxidation of FA was found to be suitable for the pseudo-first-order kinetic model and Langmuir isotherm model. Conclusion: The most effective oxidation was obtained at the original pH value (7.00) and 1:2 ratio of FA:H2 O2 under UV light.

Assessment of aflatoxin exposure using urine biomarker in pregnant and non-pregnant women in Yazd, Center of Iran

Background: Aflatoxins (AFs) are one of the most prevalent toxins, which long-term exposure to them could be a risk factor for liver cancer. AFM1 is the hydroxylated metabolite of AFB1 , therefore, the presence of AFM1 in urine samples can give an appropriate estimation of dietary AF exposure in human. Methods: The present study aimed to evaluate the excretion level of AFM1 in urine samples of pregnant and non-pregnant women in Yazd, Iran. A total of 85 urine samples (42 pregnant and 43 non-pregnant) were selected randomly from women who had referred to health centers of Yazd during March to May 2017. From each participant, a 72-hour dietary recall was asked and the data were recorded and later analyzed by ELISA kits. Results: The results showed that the mean level of AFM1 in pregnant and non-pregnant women was 8.23±2.9 and 35.5±1.05 pg mL-1, respectively. Excretion of AFM1 in urine samples had a significant relationship with some demographic factors and type of consumed foods (P<0.05). Conclusion: There was a significant relationship between the education level, place of residence, and the consumption of nuts with the excretion of AFM1 . It can be concluded that some foods distributed in Yazd are contaminated with AFs, and a significant number of people are exposed to high concentrations of AFM1 .

Assessment of ecological risk and identification sources of polycyclic aromatic hydrocarbons at coastal sediments: A case study in Bushehr Province, Iran

Background: Polycyclic aromatic hydrocarbons (PAHs) are stable and highly toxic environmental pollutants, which are produced mainly through combustion processes. The present study aimed to identify and determine PAHs compounds and their ecotoxicological effects in surface sediments of 20 stations in Bushehr province (Assaluyeh, Kangan, Khark, Emam Hasan, and Bushehr areas). Methods: All sediment samples (0-5 cm) were collected from 20 sites of Persian Gulf costs (Bushehr province, Iran). The concentration of PAHs was determined by HPLC. Then, in order to identify the sources of PAHs, ƩLPAHs/ƩHPAHs, IP/ (IP+BP), PH/AN, and AN/(PH+AN) ratios were obtained. Sediment quality guidelines (SQGs) and sediment quality criteria (SQC) were used to measure the PAHs ecotoxicological effects in sediments. Results: Based on PAHs isomeric ratios, the contaminants of sediments originated from pyrogenic resources. ƩPAHs values (ng/g dw) in sediment samples ranged from ND to 49180. The toxic equivalent concentration (TEQ car) of PAHs raged from ND-7999 ngTEQ/g. Based on SQGs and SQC, the concentrations of ƩPAHs compounds in 10% and 6% of the sampling stations exceeded effects range median (ERM) and frequent effect level (FEL), respectively, indicating negative ecological risk effects. Conclusion: Sampling stations sediments must be routinely checked for PAHs because may lead to a negative effect on the marine ecosystem, organisms, and humans.

Global evaluation of potentially harmful elements (PHEs) in potato and carrot irrigated by wastewater: A systematic review, meta-analysis, and health risk assessment

Background: We aimed to conduct a meta-analysis on the concentration of potentially harmful elements (PHEs) in carrots and potatoes irrigated by wastewater and estimate non-carcinogenic health risks among adult and children consumers. Methods: The health risk of PHEs concentration, including Pb, Cd, total Cr, Ni, Zn, Cu, and Fe, in the edible parts of carrot and potato irrigated by wastewater was investigated by a meta-analysis using a random-effects model (REM). Accordingly, the related articles were screened from international databases such as Scopus, Medline, and Embase. Results: The meta-analysis of 32 papers (38 studies) revealed that the rank order of the most accumulated PHEs in potato was Fe (86.54 mg/kg wet weight) > Zn (30.9 mg/kg wet weight) > Cu (13.7 mg/kg wet weight) > Ni (8.42 mg/kg wet weight) > Pb (5.56 mg/kg wet weight) > Cr (3.45 mg/kg wet weight) > Cd (0.58 mg/kg wet weight). This ranking for carrot was Fe (43.36 mg/kg wet weight) > Zn (36.29 mg/kg wet weight) > Ni (13.49 mg/kg wet weight) > Cu (9.79 mg/kg wet weight) > Pb (1.84 mg/kg wet weight) > Cr (1.05 mg/kg wet weight) > Cd (0.28 mg/kg wet weight). Total hazard quotient (THQ) of PHEs was higher than 1 for potato and carrot; its rank order for potato and carrot was Cu > Pb > Cd > Ni > Fe > Zn > Cr and Cd > Pb > Cu > Ni > Fe > Zn > Cr, respectively. The Cd, Pb, and Cu had also a considerable role for consumer health risk. Conclusion: According to the results, continuous monitor and control of wastewater treatment plants are necessary.

Assessment of toxicity and kinetic effects of erythromycin on activated sludge consortium by fast respirometry method

Background: The present study aimed to assess the acute impact of erythromycin (ERY) as an inhibitor on peptone mixture utilization of activated sludge (AS) consortium. Methods: For this purpose, the inhibition of oxygen consumption was used based on the ISO 8192:2007 procedure. In this method, the AS consortium (10-day age) was extracted from lab-scale membrane bioreactor, then, percentage inhibition for total, heterotrophic, and nitrifying microorganisms, in separate batch respirometric tests were calculated in the absence and presence of N-allylthiourea (ATU) as a specific Nitrification inhibitor. Results: The obtained data showed that the height of oxygen uptake rate (OUR) profiles and amount of oxygen consumption reduced with increasing ERY dose. The half-maximal effective concentration (EC50) of ERY for heterotrophic and nitrifier microorganisms were 269.4 and 1243.1 mg/L, respectively. In Run 1, the kinetic coefficients bH, fA,H, YH, and µH were calculated as 2.61 d-1, 0.44, 0.4945 mg VSS/mg COD, and 0.047 d-1, respectively. Also, for maximum ERY concentration (1000 mg/L), the kinetic coefficients bH., fA,H, YH, and µH were calculated as 2.27 d-1, 0.3, 0.4983 mg VSS/mg COD, and 0.0049 d-1, respectively. Conclusion: The findings showed that the inhibitory impact of ERY was observed as a decrease in the amount of oxygen consumption by OUR profiles in rapid respirometric method (ISO 8192), which offered a novel insight for the acute inhibitory impact of this antibiotic. Also, chemical oxygen demand (COD) as an overall substrate parameter is most helpful in interpreting the behavior and the metabolic functions of AS systems.