Yaghoub Hajizadeh

Phytoremediation of VOCs from indoor air by ornamental potted plants: A pilot study using a palm species under the controlled environment

Volatile organic compounds (VOCs) in indoor air have recently raised public concern due to their adverse health effects. One of hazardous VOC is Formaldehyde which can cause sensory irritation and induce nasopharyngeal cancer. The aim of this study was to investigate potted plant-soil system ability in formaldehyde removal from indoor air. We applied one of common interior plant from the palm species, Chamaedorea elegans, inside a chamber under the controlled environment. Entire plant, growing media and roots contribution in formaldehyde were evaluated by continuously introduction of different concentrations of formaldehyde into the chamber (0.66-16.4 mg m-3) each over a 48-h period. Our findings showed that the plant efficiently removed formaldehyde from polluted air by 65-100%, depending on the inlet concentrations, for a long time exposure. A maximum elimination capacity of 1.47 mg/m2. h was achieved with an inlet formaldehyde concentration of 14.6 mg m-3. The removal ratio of areal part to pot soil and roots was 2.45:1 (71%: 29%). The plants could remove more formaldehyde in light rather than dark environment. Concentrations up to 16.4 mg m-3 were not high enough to affect the plants growth. However, a trivial decrease in chlorophyll content, carotenoid and water content of the treated plants was observed compared to the control plants. Thus, the palm species tested here showed high tolerance and good potential of formaldehyde removal from interior environments. Therefore, phytoremediation of VOCs from indoor air by the ornamental potted plants is an effective method which can be economically applicable in homes and offices.

Effectiveness of nanozeolite modified by cationic surfactant in the removal of disinfection by‑product precursors from water solution

Aim: In this study the performance of a natural nanozeolite, modified with a cationic surfactant, on the adsorption of humic acid from water was investigated in a batch system. Materials and Methods: Clinoptilolite as a natural nanozeolite was modified with different doses of a cationic surfactant solution, hexadecyltrimethylammonium bromide (HDTMA-Br), at dosages from 0.5 to 10 g/l. The modified adsorbents were individually added to synthetic water samples containing a known amount of humic acid and put on the shaker for two hours, at room temperature. Humic acid (HA) concentrations, turbidity, and pH were measured before and after the adsorption process. Results: According to the results obtained, and based on the statistical analysis (Pearson correlation statistical test), there was a clear correlation between the cationic surfactant dosage and HA removal (Pvalue Conclusions: This study showed that modification of nanozeolite by cationic surfactants, to reduce its negative surface charge, could markedly improve its efficiency in the adsorption of disinfection by-product precursors from an aqueous solution. The HDTMA-Br/Clinoptilolite nanozeolite (CNZ) ratio of 0.07, pH have to coincide in iso-electric point, can be an optimum ratio for the modification.

A Systematic Review on the Effects of Polycyclic Aromatic Hydrocarbons on Cardiometabolic Impairment

Background: Various epidemiological studies have shown that exposure to environmental pollutants including polycyclic aromatic hydrocarbons (PAHs) might increase the risk of cardiovascular diseases (CVDs) and their risk factors. This study aims to systematically review the association of PAH exposure with metabolic impairment. Methods: Data were collected by searching for relevant studies in international databases using the following keywords: “polycyclic aromatic hydrocarbon” + “cardiovascular disease,” PAH + CVD, polycyclic aromatic hydrocarbon and “air pollutant” + “CVD,” and the desired data were extracted and included in the study according to the systematic review process. Results: From the 14 articles included in the present systematic review, eight articles were conducted on the relationship between PAH and CVDs, four articles were conducted to examine the association of PAH exposure with blood pressure (BP), and two articles investigated the link between PAH and obesity. Conclusions: Most studies included in this systematic review reported a significant positive association of PAH exposure with increased risk of CVDs and its major risk factors including elevated BP and obesity. These findings should be confirmed by longitudinal studies with long-term follow-up.

Hybrid coagulation-UF processes for spent filter backwash water treatment: a comparison studies for PAFCl and FeCl 3 as a pre-treatment

In this study, the reclamation of clean water from spent filter backwash water (SFBW) was investigated through pilot-scale experiments. The pilot plant consisted of pre-sedimentation, coagulation, flocculation, clarification, and ultrafiltration (UF). Two coagulants of PAFCl and FeCl3 were investigated with respect to their performance on treated SFBW quality and UF membrane fouling. At the optimum dose of PAFCl and FeCl3 turbidity removal of 99.6 and 99.4% was attained, respectively. PAFCl resulted in an optimum UV254, TOC, and DOC removal of 80, 83.6, and 72.7%, respectively, and FeCl3 caused the removal of those parameters by 76.7, 80.9, and 65.9%, respectively. PAFCl removed hydrophilic and transphilic constituent better than FeCl3, but FeCl3 had, to some extent, higher affinities to a hydrophobic fraction. It was concluded that PAFCl showed a better coagulation performance in most cases and caused a lower membrane fouling rate compared to FeCl3. Finally, the treated SFBW with both coagulant-UF systems met the drinking water standards.

Efficiency enhancement of multi-walled carbon nanotubes by ozone for benzene removal from aqueous solution

Aims: Modification of multi-walled carbon nanotubes (MWCNTs) via ozone was carried out to enhance removal benzene from aqueous solutions. Materials and Methods: Multi-walled carbon nanotubes purchased from the Iranian Research Institute of the Petroleum Industry was oxidized by ozone generator at %80 intensity for 5 min and in 30% NaOCl. Results: The Fourier transform infrared analysis showed that the peaks corresponded to the hydroxyl and carboxylic acid groups in modified MWCNTs (MMWCNTs) are more intense than that in non-MMWCNTs. The images of scanning electron microscopy indicated that the MMWCNTs have a lower degree of entanglement with increased porosity compared to the nonmodified one. X-ray diffraction test showed that structural crystallization was increased following the modification. After modification, the efficiency of MWCNTs was increased by 20%. The optimum condition for initial benzene concentration, MWCNT dose, contact time, and pH was: 100 mg/L, 2000 mg/L, 20 min, and 5 respectively. Conclusion: Our research suggested that ozone modification can be a simple method in improvement of the MWCNTs efficiency for removal of benzene from aqueous solution.

Association of polycyclic aromatic hydrocarbons with cardiometabolic risk factors and obesity in children

A limited body of evidence exists on the association of exposure to polycyclic aromatic hydrocarbons (PAHs) with cardiometabolic risk factors and obesity in children. No study has evaluated these associations in subgroups of children with and without excess weight, and those with and without cardiometabolic risk factors. We aimed to investigate the association between PAH exposure and cardiometabolic risk factors in children independent of their weight status. The secondary aim was to evaluate the obesogen properties of PAHs in children independent of their cardiometabolic risk factors. This study was based on a representative sample of 186 children (aged 6-18 years) living in Isfahan, Iran (2014-2016). We enrolled four groups of participants with and without excess weight and with and without cardiometabolic risk factor. Urinary levels of monohydroxy PAHs (OH-PAHs) were measured twice, six months apart. Logistic regression models were developed to estimate the associations of tertiles of urinary OH-PAH concentrations with cardiometabolic risk factors and excess weight, adjusted for the relevant covariates. The findings in all participants combined showed that increased risk of cardiometabolic risk factors and excess weight was associated with exposure to most of evaluated PAHs. Exposure to 1-hydroxypyrene was associated with higher risk of cardiometabolic risk factors in participants with excess weight. Exposure to 2-Naphtol was also associated with higher risk of cardiometabolic risk factors in both groups, but the associations were not significant (p < 0.1). For participants without cardiometabolic risk factors, exposure to 2-naphtol, 9-phenanthrol, and ∑ OH-PAH was associated with increased risk of obesity. For participants with cardiometabolic risk factors, we observed similar pattern of associations for 2-naphtol and ∑ OH-PAH, but the associations were not statistically significant (p < 0.1). We found that exposure to PAHs could possibly explain, in part, the cardiometabolic risk factors in children with excess weight as well as obesity in children with normal cardiometabolic profile.

Measurement of airborne asbestos levels in high traffic areas of Shiraz, Iran, in winter 2014

Aims: Levels of asbestos fibers in ambient air of dense areas of Shiraz, Iran, were monitored in winter 2014. Materials and Methods: Sampling was carried out by directing air flow to a mixed cellulose ester membrane filter mounted on an open-faced filter holder using a low flow sampling pump. Fiber counting on the filters was conducted using both phase contrast microscopy (PCM) method to determine total fibers and scanning electron microscopy (SEM) method to identify nonasbestos from asbestos fibers. Results: The average concentration of asbestos fibers in the ambient air of the study in different areas of Shiraz were 1.18 ± 0.28 PCM f/L and 13.64 ± 2.87 SEM f/L, in which a maximum level was measured in Valiasr square (1.89 ± 0.54 PCM f/L [20.37 ± 5.55 SEM f/L]), and that of in Moallem square was in minimum (1.05 ± 0.47 PCM f/L [12.24 ± 3.04 SEM f/L]). Conclusions: The averages of asbestos fibers in all sampling points were higher than the WHO suggested standards for ambient air (0.05 PCM f/L, 2.2 SEM f/L). This may be attributed to the frequent occurrence of heavy traffic, the existence of relevant industries in and around the city, and the topographic characteristics of the city. Therefore, immediate courses of action such as product substitution, traffic smoothing, and industrial sites relocating should be taken to eliminate asbestos fibers emission.

Determination of an empirical formula for organic composition of mature compost produced in Isfahan-Iran composting plant in 2013

Aims: The aims of this study were to analyze the carbon, hydrogen, nitrogen, sulfur, and oxygen (CHNS-O) content of compost derived from Isfahan-Iran municipal solid waste using thermal elemental analyzer and to develop an approximate empirical chemical formula for the organic fraction of the mature compost as a function of its elemental composition. Materials and Methods: The compost samples (1 kg) were collected from different parts of the windrows and thoroughly mixed in accordance with standard methods. After drying and milling, each sample was introduced to an elemental analyzer to measure their CHNS-O contents. The moisture content, temperature, and pH value were also monitored in three different windrows during the process. Results: An approximate chemical empirical formula calculated for the organic fraction of the compost was: C 204 H 325 O 85 N 77 S. Conclusion: According to this formula, it appears that the mature compost produced in the site contains higher value of nondegradable nitrogen, which leads to a lower total C/N ratio. Therefore, improving the primary separation of raw material in the composting plant particularly severance of plastic materials can result in an optimum C/N ratio.

Myeloperoxidase levels predicts angiographic severity of coronary artery disease in patients with chronic stable angina.

Background : Myeloperoxidase (MPO) has an important role in the both processes of inflammation and oxidative stress. It plays proatherogenic role via low-density lipoprotein oxidation, functional inactivation of the high-density lipoprotein and endothelial dysfunction, and seems to be involved in the atherogenesis of coronary arteries. This study designed to evaluate the association between the plasma MPO levels and angiographic severity of coronary artery disease (CAD) in patients with the stable CAD. Materials and Methods: Sixty-eight patients who had documented CAD with angiography and 66 subjects who had normal angiography were selected as case and the control groups for this study, respectively. Gensini scoring system was used for evaluation of severity of coronary artery stenosis. Plasma MPO and C-reactiveprotein (CRP) levels of both case and control groups were determined. Results: Plasma MPO levels and CRP levels were significantly higher in CAD patients (P < 0.001), and plasma levels of MPO and CRP were correlated with Genssini scores. Conclusions: Our findings indicated that the plasma MPO levels increase in patients with stable CAD and hence that, it can be used as adiagnostic factor to predict the coronary artery atherosclerosis severity in stable CAD patients; However, it needs further widespread investigations to achieve an accurate cut point.

Environmental and biological monitoring of exposures to VOCs in a petrochemical complex in Iran

Exposure to volatile organic compounds (VOCs) can cause cancers in human. This study aimed to measure the concentration of four VOCs including benzene, styrene, ethylbenzene, and phenol in ambient air of a petrochemical complex in Iran. Also, their urinary metabolites including phenol, mandelic acid (MA), and phenylglyoxylic acid (PGA) in the workers were monitored. Urine samples were collected before and after the 8-h workshift according to the NIOSH methods. They were analyzed by a gas chromatograph coupled with a flame ionization detector (GC-FID). High levels of the ambient VOCs were detected in the units of recovery and olefin. The levels of ethylbenzene and phenol were less than the guidelines suggested by NIOSH and ACGIH. However, in some cases, the amounts of benzene and styrene were higher than the guidelines. Excellent positive correlations were observed between VOCs exposure and their urinary metabolites (r2 > 0.90), except for benzene (r2 = 0.26). Our finding verified that urinary biomarkers can be applied as bioindicators for ambient exposure to VOCs. There is a risk of exposure to high levels of the pollutants in some of the sites, and it is necessary to adopt some preventive measures to reduce health risk.