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148 result(s) for "dimethyl phthalate"
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Oxidative degradation/mineralization of dimethyl phthalate (DMP) from plastic industrial wastewater using ferrate(VI)/TiO2 under ultraviolet irradiation
A novel ferrate(VI)/titanium dioxide/ultraviolet [Fe(VI)/TiO 2 /UV] system was successfully established for the photocatalytic oxidation of dimethyl phthalate (DMP). This system demonstrated a higher removal efficiency of DMP (95.2%) than the conventional TiO 2 /UV and Fe(VI) alone systems (51.8% and 23.5%, respectively) and produced obvious synergistic effects. Response surface methodology (RSM), based on a three level, three independent variables design, was conducted through Design Expert 8.0.6 program, and a second-order polynomial model ( R 2 = 0.998) was developed to quantitatively describe the photocatalysis of TiO 2 combined with Fe(VI) oxidation under ultraviolet irradiation. The fresh TiO 2 and photochemical reacted Fe(VI)/TiO 2 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and element dispersive spectrum (EDS), which indicated that Fe(VI) was imprinted into the TiO 2 , and the surface adsorbed Fe-O-(organic) materials inhibited DMP degradation. This photocatalytic oxidant showed high activity and stability after nine cycles without loss of its effectiveness (counting from the second cycle). The intermediates/products of DMP were analyzed by gas chromatography-mass spectrometry. The proposed pathway for DMP degradation involved one electron transfer of hydroxyl radical and breaking of the ester bond and benzene ring. The mineralization efficiencies of DMP in actual industrial wastewater and simulated water were 87.1% and 95.2%, respectively, suggesting practical field applications. A ecotoxicity test (17.3% inhibition on bioluminescence) in treating actual industrial wastewater containing DMP implied that the proposed Fe(VI)/TiO 2 /UV had a potential for industrial water treatment.
Influences of Dimethyl Phthalate on Bacterial Community and Enzyme Activity in Vertical Flow Constructed Wetland
Dimethyl phthalate (DMP), belonging to the family of Phthalate esters (PAEs), is a plasticizer and has been widely used in the world for many years. Nowadays, it has become a ubiquitous environmental pollutant and is listed as an environmental priority pollutant by China’s Environmental Monitoring Center. The purpose of this study is to estimate the responses of the bacterial community and enzyme activity to DMP contamination in three vertical flow constructed wetlands (VFCW), namely the constructed wetland A (planted with Pennisetum sinese Roxb), constructed wetland B (planted with Pennisetum purpureum Schum.), and constructed wetland C (unplanted), respectively. The results showed that the relative percentages of some genera associated with nitrogen metabolism and the function of degrading aromatic hydrocarbons were increased by DMP contamination, such as Dechloromonas agitata, Pleomorphomonas sp., Denitratisoma oestradiolicum, Plasticicumulans lactativorans, Novosphingobium sp., Alicycliphilus denitrificans, and Thauera sp. Meanwhile, principal coordinate analysis (PCA) analysis showed that the addition of DMP divided 12 samples into two groups as followed: one was the DMP group containing a-1, a-2, b-1, b-2, c-1 and c-2 while the other was no DMP group including A-1, A-2, B-1, B-2, C-1 and C-2. It indicated that DMP was the main reason for this change. In addition, by monitoring the activity of substrate enzymes, the activity of urease, phosphatase, catalase, and invertase in the wetlands before and after the experiment, these were significantly higher in the upper layer than in the lower layer and maintained high activity. Ultimately, the average influent concentration of DMP in three VFCWs was 8.12 mg/L and the average removal efficiency of the effluent was over 90%. Our results suggested that DMP was an important factor affecting the microbial community structure of wetland and the upper layer of the VFCW was the main site for the degradation of DMP. VFCW has great potential for the removal of the high concentration of DMP and it can be a good choice for the treatment of PAEs.
Biotin–streptavidin-amplified real-time immune-PCR assay for detecting dimethyl phthalate in beverage and drinking water samples
Dimethyl phthalate (DMP), one family of the phthalic acid diesters (PAEs), is an increasing widely used plasticizer. A sensitive and high-throughput direct competitive biotin–streptavidin-amplified system based on real-time immune-PCR (BA-rt-IPCR) techniques was developed for detecting DMP in beverage and drinking water samples. In our assay, we selected dimethyl 4-aminophthalate as the optimal DMP hapten to prepare high titer of rabbit polyclonal anti-DMP antibodies (pAb-DMP). Under the optimized conditions, the proposed method was used to detect DMP with a linearity range from 10 to 100 ng L −1 , and the limit of detection (LOD) was 1.98 pg L −1 . Finally, the results about DMP in beverage and drinking water samples were consistent with those using gas chromatography–mass spectrometry (GC-MS), which proved that the proposed immunoassay for detecting DMP in the environment was accurate, reliably rapid, and receptive.
Measurement of phthalate acid esters in non-alcoholic malt beverages by MSPE-GC/MS method in Tehran city: chemometrics
Phthalic acid esters (PAEs) are compounds that are used in the bottle as the main plasticizers. Therefore, the possibility of releasing phthalate esters into beverages is very high and there is a concern to consumer health and monitoring organizations. The aim of this research was to assess the phthalic acid esters (di-n-octyl phthalate (DNOP), butyl benzyl phthalate (BBP), dimethyl phthalate (DMP), diethyl phthalate (DEP) and dibutyl phthalate (DBP), bis(di-ethylhexyl) phthalate (DEHP), and total PAEs) in bottled non-alcoholic malt beverages ( n = 120) by multi-walled carbon nanotubes were magnetized with iron (MWCNT-Fe 3 O 4 ) using gaschromatography/mass spectrometry (GC-MS). The results showed that the highest and the lowest levels of total phthalate esters in samples were 9483.93 and 2412.50 ng/L, respectively. The mean of DEHP which has also been found to be carcinogenic in all samples was lower than 5944.73 ng/L. The highest concentration of DEHP in four samples was upper than 8957.87 ng/L. Perceived limit of detection (LOD) ranged from 13 to 30 ng/L and the limit of quantification (LOQ) ranged from 39 to 90 ng/L. Multivariate techniques and heat map visualization were used to assess the correlation among the type and levels of PAEs with the brand, color, product date, pH, sugar, volume, and gas pressure. Therefore, based on heat map and principal component analysis (PCA) results, the DEHP and total PAEs were the closest accessions, indicating that these variables had similar trends. Based on the results, it can be stated that due to the low average of total phthalate esters in non-alcoholic malt beverages, there is no serious health hazard of these compounds for humans.
A critical analysis of the biological impacts of plasticizers on wildlife
This review provides a critical analysis of the biological effects of the most widely used plasticizers, including dibutyl phthalate, diethylhexyl phthalate, dimethyl phthalate, butyl benzyl phthalate and bisphenol A (BPA), on wildlife, with a focus on annelids (both aquatic and terrestrial), molluscs, crustaceans, insects, fish and amphibians. Moreover, the paper provides novel data on the biological effects of some of these plasticizers in invertebrates, fish and amphibians. Phthalates and BPA have been shown to affect reproduction in all studied animal groups, to impair development in crustaceans and amphibians and to induce genetic aberrations. Molluscs, crustaceans and amphibians appear to be especially sensitive to these compounds, and biological effects are observed at environmentally relevant exposures in the low ng l1 to g l1 range. In contrast, most effects in fish (except for disturbance in spermatogenesis) occur at higher concentrations. Most plasticizers appear to act by interfering with the functioning of various hormone systems, but some phthalates have wider pathways of disruption. Effect concentrations of plasticizers in laboratory experiments coincide with measured environmental concentrations, and thus there is a very real potential for effects of these chemicals on some wildlife populations. The most striking gaps in our current knowledge on the impacts of plasticizers on wildlife are the lack of data for long-term exposures to environmentally relevant concentrations and their ecotoxicity when part of complex mixtures. Furthermore, the hazard of plasticizers has been investigated in annelids, molluscs and arthropods only, and given the sensitivity of some invertebrates, effects assessments are warranted in other invertebrate phyla.
Phthalates leaching from plastic food and pharmaceutical contact materials by FTIR and GC-MS
Phthalates are often used as plasticizers in the production of plastic food contact materials (FCMs) and pharmaceutical contact materials (PCMs), and having in mind that they are not bound to plastics, phthalates may easily leach from plastics under certain conditions. The aim of this research is determination of phthalates leaching potential from different plastic materials and quantitative determination of 5 phthalates (dimethyl phthalate (DMP), di-n-butyl phthalate (DnBP), benzyl butyl phthalate (BBP), diethyl hexyl phthalate (DEHP), and di-n-octyl phthalate (DOP)) in 44 different plastic articles of 7 different plastic polymers used as FCMs and PCMs by FTIR, GC-MS, and gravimetric methods. The FTIR technique is shown to be rapid method for determination of phthalate content in PVC articles. Comparing of FTIR method with GC-MS and gravimetric showed that separation and quantitative determination of each phthalate separately favor the GC-MS method, because FTIR method determines the total amount of phthalate content. However, the FTIR method is less expensive and demanding in terms of sample preparation, which is suited for use in pre-screening analysis. The results of GC-MS phthalates determination showed that PVC articles used as PCMs contain DEHP in significant amount, from 5.19 to 28.76% by weight and could be a potential risk to human health.
Distribution, health risk assessment, and water quality criteria of phthalate esters in Poyang Lake, China
Although China has been the main manufacturer and consumer of phthalate esters (PAEs), human health ambient water quality criteria (AWQCs) have not been proposed for these chemicals. In this study, the distribution and bioaccumulation of six PAEs (dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), bis (2-ethylhexyl) phthalate (DEHP), and di-n-octyl phthalate (DnOP)) were investigated in 11 edible fish species collected from Poyang Lake, China. The results showed that the total concentrations of the six PAEs in the fish ranged between 118.63 and 819.84 μg/kg wet weight (mean of 327.50 ± 190.44 μg/kg). DMP, DEP, DBP, and DEHP were detected in all samples, of which DEHP and DBP were two of the most predominant phthalates, accounting for more than 90% of the total PAEs. The DEHP concentrations in fish with different habitat preferences were different, demersal species were significantly higher than pelagic species (p < 0.05). The mean natural logarithmic bioaccumulation factors (log BAFs) of PAEs increased with increasing lipophilicity of the substances, which yielded the following regression equation: log BAF (L/kg) = 0.103 log Kow + 2.158 (r2 = 0.940, p < 0.05, n = 4). Using this quantitative structure–activity relationship to calculate BAFs for the remaining undetected substances (BBP and DnOP) to derive AWQCs. According to the natural parameters, the human health AWQCs relating to PAE concentrations for water and fish consumption were derived as 9.4 × 103 (DMP), 5.0 × 102 (DEP), 4.2 × 101 (DBP), 1.1 (BBP), 8.6 × 10− 2 (DEHP), and 2.0 (DnOP) μg/L. Human health risk assessment indicated that the dietary intake of DEHP may exert a carcinogenic effect on residents of the Poyang Lake region. The results provide important input to assess the health risk posed by PAEs contaminated surface water.
Spatial Distribution and Chronic Ecological risk Assessment of Typical Phthalate Esters in the Surface Waters of China
The chronic ecological risks posed by residual PAEs in China remain unclear. In this study, we analyzed the spatial distribution of five typical PAEs in the surface waters of China, dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP), butylbenzyl phthalate (BBP), diethyl phthalate (DEP), and dimethyl phthalate (DMP). The highest concentration of PAEs were detected in the Liao River, ranging from 5 to 79.8 µg/L. DBP was of the PAEs type with the highest concentration in the surface waters in China. By fitting the species sensitivity distribution curves base on the collected data over the past decade, the chronically hazardous concentrations affecting 5% of the aquatic species were calculated to be 0.018, 0.022, 0.062, 0.851, and 9.437 mg/L for DBP, DEHP, BBP, DEP, and DMP, respectively. Thus, DBP, DEHP, and BBP pose the greatest threat to aquatic organisms, and PAEs pose high ecological risks in the Liao, Huangpu, and Pearl Rivers.
Degradation of dibutyl phthalate by Paenarthrobacter sp. Shss isolated from Saravan landfill, Hyrcanian Forests, Iran
Phthalic acid esters are predominantly used as plasticizers and are industrially produced on the million ton scale per year. They exhibit endocrine-disrupting, carcinogenic, teratogenic, and mutagenic effects on wildlife and humans. For this reason, biodegradation, the major process of phthalic acid ester elimination from the environment, is of global importance. Here, we studied bacterial phthalic acid ester degradation at Saravan landfill in Hyrcanian Forests, Iran, an active disposal site with 800 tons of solid waste input per day. A di-n-butyl phthalate degrading enrichment culture was established from which Paenarthrobacter sp. strain Shss was isolated. This strain efficiently degraded 1 g L–1 di-n-butyl phthalate within 15 h with a doubling time of 5 h. In addition, dimethyl phthalate, diethyl phthalate, mono butyl phthalate, and phthalic acid where degraded to CO2, whereas diethyl hexyl phthalate did not serve as a substrate. During the biodegradation of di-n-butyl phthalate, mono-n-butyl phthalate was identified in culture supernatants by ultra-performance liquid chromatography coupled to electrospray ionization quadrupole time-of-flight mass spectrometry. In vitro assays identified two cellular esterase activities that converted di-n-butyl phthalate to mono-n-butyl phthalate, and the latter to phthalic acid, respectively. Our findings identified Paenarthrobacter sp. Shss amongst the most efficient phthalic acid esters degrading bacteria known, that possibly plays an important role in di-n-butyl phthalate elimination at a highly phthalic acid esters contaminated landfill.