| 1. |
- Fiedler, Heidelore, Dr. 1953-, et al.
(författare)
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Perfluoroalkane acids in human milk under the global monitoring plan of the Stockholm Convention on Persistent Organic Pollutants (2008-2019)
- 2022
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Ingår i: Frontiers of Environmental Science and Engineering. - : Springer. - 2095-2201 .- 2095-221X. ; 16:10
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Tidskriftsartikel (refereegranskat)abstract
- Within the global monitoring plan (GMP) established by article 16 of the Stockholm Convention on Persistent Organic Pollutants, perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS) are recommended for analysis in core matrices to assess occurrence and changes geographically and with time. In 101 samples consisting of 86 national pools and 15 pools from States in Brazil obtained between 2008 and 2019, PFHxS was detected in 17% of the national pools and none in Brazil. PFOA and PFOS had a detection frequency of 100% and 92%, respectively. Other perfluoroalkane substances (PFAS) had either low detection frequencies and median values of zero (carboxylic acids C-4-C-11 ; except PFOA) or could not be quantified in any sample (sulfonic acids, C-4-C-10, and long-chain carboxylic acids, C-12-C-14). Correlation between PFOA and PFOS was moderately (r = 0.58). Whereas median values were almost identical (18.9 pg/g f.w. for PFOS; 18.6 pg/g f.w. for PFOA), PFOS showed larger ranges (< 6.2 pg/g f.w.-212 pg/g f.w.) than PFOA (< 6.2 pg/g f.w.-63.4 pg/g f.w.). It was shown that wealthier countries had higher PFOA concentrations than poorer countries. No difference in concentrations was found for samples collected in countries having or not having ratified the Stockholm Convention amendments to list PFOS or PFOA. The goal to achieve 50% decrease in concentrations within ten years was met by Antigua and Barbuda, Kenya, and Nigeria for PFOS and by Antigua and Barbuda for PFOA. In a few cases, increases were observed; one country for PFOS, four countries for PFOA.
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| 2. |
- Liu, Xiaotu, et al.
(författare)
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Potential sources of unintentionally produced PCB, HCB, and PeCBz in China : A preliminary overview
- 2018
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Ingår i: Frontiers of Environmental Science and Engineering. - : Higher Education Press. - 2095-2201 .- 2095-221X. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- Under the Stockholm Convention on Persistent Organic Pollutants (POPs), China is required not only to reduce polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) but also unintentionally produced polychlorinated biphenyls (PCB), hexachlorobenzene (HCB) and pentachlorobenzene (PeCBz). A baseline of the sources in China that generate these unintentional POPs is needed for both research and regulation purposes. In this paper, we have compiled production data of potential sources in China and assessed them in five-year intervals from 2000 to 2015. Most of these activities experienced changes from rapid growth to slow growth. Measured data for PCB, HCB and PeCBz in samples collected from potential sources in China were reviewed. Most information was associated to thermal processes with high potential of emission, including waste incineration and ferrous and non-ferrous metal production. In addition, high levels of PCB, HCB and PeCBz were found as impurities in a few chlorinated products or as by-products in solvent production, which suggested organochlorine industry might be important sources. Finally, based on the studies reviewed, recommendations for future actions in research and policy as well as a few regulatory issues in China are discussed.
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| 3. |
- Ma, Shuai, et al.
(författare)
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Modification of the activated sludge model for chemical dosage
- 2015
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Ingår i: Frontiers of Environmental Science and Engineering in China. - : Springer Science and Business Media LLC. - 2095-2201 .- 2095-221X. ; 9:4, s. 694-701
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Tidskriftsartikel (refereegranskat)abstract
- Full-scale experiments have been carried out to adapt the activated sludge model ASM2d to include the influence of metal dosage (Fe3+ and Al3+) for phosphorus removal. Phosphorus removal rates, nitrification rates, as well as pH and sludge settling performance, were evaluated as functions of the metal dosages. Furthermore, models relating certain parameters to the dosage of chemicals have been derived. Corresponding parameters in the ASM2d and the secondary settler models, included in the Benchmark Simulation Model No 1 (BSM1), have been modified to take the metal influence into consideration. Based on the effluent limits and penalty policy of China, an equivalent evaluation method was derived for the total cost assessment. A large number of 300-day steady-state and 14-day open-loop dynamic simulations were performed to demonstrate the difference in behavior between the original and the modified BSM1. The results show that 1) both in low and high mole concentrations, Fe3+ addition results in a higher phosphorus removal rate than Al3+; 2) the sludge settling velocity will increase due to the metal addition; 3) the respiration rate of the activated sludge is decreased more by the dosage of Al3+ than Fe3+; 4) the inhibition of Al3+ on the nitrification rate is stronger than that of Fe3+; 5) the total operating cost will reach the minimum point for smaller dosages of Fe3+, but always increase with Al3+ addition.
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| 4. |
- Ma, Shuai, et al.
(författare)
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Short-term prediction of influent flow rate and ammonia concentration in municipal wastewater treatment plants
- 2014
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Ingår i: Frontiers of Environmental Science and Engineering in China. - : Springer Science and Business Media LLC. - 2095-2201 .- 2095-221X. ; 8:1, s. 128-136
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Tidskriftsartikel (refereegranskat)abstract
- The prediction of the influent load is of great importance for the improvement of the control system to a large wastewater treatment plant. A systematic data analysis method is presented in this paper in order to estimate and predict the periodicity of the influent flow rate and ammonia (NH3) concentrations: 1) data filtering using wavelet decomposition and reconstruction; 2) typical cycle identification using power spectrum density analysis; 3) fitting and prediction model establishment based on an autoregressive model. To give meaningful information for feedforward control systems, predictions in different time scales are tested to compare the corresponding predicting accuracy. Considering the influence of the rainfalls, a linear fitting model is derived to estimate the relationship between flow rate trend and rain events. Measurements used to support coefficient fitting and model testing are acquired from two municipal wastewater treatment plants in China. The results show that 1) for both of the two plants, the periodicity affects the flow rate and NH3 concentrations in different cycles (especially cycles longer than 1 day); 2) when the flow rate and NH3 concentrations present an obvious periodicity, the decreasing of prediction accuracy is not distinct with increasing of the prediction time scales; 3) the periodicity influence is larger than rainfalls; 4) the rainfalls will make the periodicity of flow rate less obvious in intensive rainy periods.
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| 5. |
- Meng, Yuan, et al.
(författare)
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Fate and risk assessment of emerging contaminants in reclaimed water production processes
- 2021
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Ingår i: Frontiers of Environmental Science and Engineering. - : Springer. - 2095-2201 .- 2095-221X. ; 15:5
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Tidskriftsartikel (refereegranskat)abstract
- Reclaimed water has been widely applied in irrigation and industrial production. Revealing the behavior of emerging contaminants in the production process of reclaimed water is the first prerequisite for developing relevant water quality standards. This study investigated 43 emerging contaminants, including 22 pharmaceuticals and personal care products (PPCPs), 11 organophosphorus flame retardants (OPFRs), and 10 antibiotic resistance genes (ARGs) in 3 reclaimed wastewater treatment plants (RWTPs) in Beijing. The composition profiles and removal efficiencies of these contaminants in RWTPs were determined. The results indicated that the distribution characteristics of the different types of contaminants in the three RWTPs were similar. Caffeine, sul2 and tris(1-chloro-2-propyl) phosphate were the dominant substances in the wastewater, and their highest concentrations were 27104 ng/L, 1.4 x 10(7) copies/mL and 262 ng/L, respectively. Ofloxacin and sul2 were observed to be the dominant substances in the sludge, and their highest concentrations were 5419 ng/g and 3.7 x 10(8) copies/g, respectively. Anaerobic/anoxic/oxic system combined with the membrane bioreactor process achieved a relatively high aqueous removal of PPCPs (87%). ARGs and OPFRs were challenging to remove, with average removal rates of 6.5% and 31%, respectively. Quantitative meta-analysis indicated that tertiary treatment processes performed better in emerging contaminant removal than secondary processes. Diethyltoluamide exhibited the highest mass load discharge, with 33.5 mg/d per 1000 inhabitants. Octocrylene and tris(2-ethylhexyl) phosphate posed high risks (risk quotient>1.0) to aquatic organisms. This study provides essential evidence to screen high priority pollutants and develop corresponding standard in RWTPs.
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| 6. |
- Mustafa, Majid, et al.
(författare)
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Identification of resistant pharmaceuticals in ozonation using QSAR modeling and their fate in electro-peroxone process
- 2021
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Ingår i: Frontiers of Environmental Science and Engineering. - : Higher Education Press. - 2095-2201 .- 2095-221X.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The abatements of 89 pharmaceuticals in secondary effluent by ozonation and the electro-peroxone (Eperoxone) process were investigated. Based on the results, a quantitative structure-activity relationship(QSAR) model was developed to explore relationship between chemical structure of pharmaceuticalsand their oxidation rates by ozone. The orthogonal projection to latent structure (OPLS) method wasused to identify relevant chemical descriptors of the pharmaceuticals, from large number ofdescriptors, for model development. The resulting QSAR model, based on 44 molecular descriptorsrelated to the ozone reactivity of the pharmaceuticals, showed high goodness of fit (R2 = 0.963) andpredictive power (Q2 = 0.84). After validation, the model was used to predict second-order rateconstants of 491 pharmaceuticals of special concern (kO3 ) including the 89 studied experimentally. The predicted kO3 values and experimentally determined pseudo-first order rate constants of thepharmaceuticals’ abatement during ozonation (kOZ) and the E-peroxone process (kEP) were then usedto assess effects of switching from ozonation to the E-peroxone process on removal of thesepharmaceuticals. The results indicate that the E-peroxone process could accelerate the abatement ofpharmaceuticals with relatively low ozone reactivity (kO3 < ~102 M–1.s–1) than ozonation (3–10 min versus 5–20 min). The validated QSAR model predicted 66 pharmaceuticals to be highly O3-resistant.The developed QSAR model may be used to estimate the ozone reactivity of pharmaceuticals ofdiverse chemistry and thus predict their fate in ozone-based processes.
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| 7. |
- Olsson, Gustaf
(författare)
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Water, energy and food interactions-Challenges and opportunities
- 2013
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Ingår i: Frontiers of Environmental Science and Engineering in China. - : Springer Science and Business Media LLC. - 2095-2201 .- 2095-221X. ; 7:5, s. 787-793
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Tidskriftsartikel (refereegranskat)abstract
- Water and energy are inextricably linked, and as a consequence both have to be addressed together. This is called the water-energy nexus. When access to either is limited, it becomes obvious that it is necessary to consider their interdependence. Population growth, climate change, urbanization, increasing living standards and food consumption will require an integrated approach where food, water and energy security are considered together. In this paper we examine water, energy and food security and their couplings. The nexus also creates conflicts between water use, energy extraction and generation as well as food production. Some of these conflicts are illustrated. It is argued that there is an urgent need for integrated planning and operation. Not only will better technology be needed, but also better integration of policies, organizations and political decisions.
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| 8. |
- Wang, Bin, et al.
(författare)
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Insight of chemical environmental risk and its management from the vinyl chloride accident
- 2023
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Ingår i: Frontiers of Environmental Science and Engineering. - : Springer. - 2095-2201 .- 2095-221X. ; 17:4
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Tidskriftsartikel (refereegranskat)abstract
- The combustion of vinyl chloride (VC) after the train derailment accident in Ohio, USA in February, 2023 has caused widespread concern around the world. This paper tried to analyze several issues concerning the accident, including the appropriateness of the VC combustion in the emergency response in this accident, the meanings of so-called "controlled combustion", the potential environmental risks caused by VC and combustion by-products, and follow-up work. In our view, this accident had surely caused environmental and health risks to some extent. Hence, a comprehensive environmental risk assessment is necessary, and then the site with risk should be comprehensively remediated, hazardous waste should be harmlessly treated as soon as possible. Finally, this accident suggests that further efforts should be taken to bridge the gap between chemical safety management and their environmental risk management.
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