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How does natural resource dependence affect public education spending?
2019
Sun, Hua-ping | Sun, Wei-feng | Geng, Yong | Yang, Xi | Edziah, Bless Kofi
The “resource curse” phenomenon has been the subject of extensive research, with its causes and transmission mechanisms primarily examined from the perspectives of economic development and rent seeking. Education is a major factor contributing to economically sustainable development, owing to its potential for improving cognition and skill levels and thereby enhancing worker productivity. The crowding-out or crowding-in effect of natural resource dependence on public education spending has been identified as one of the key mechanisms of the resource curse or blessing. Using panel data from 31 Chinese provinces, this empirical study revealed a positive correlation between natural resource dependence and public education expenditure, demonstrating the impact of the crowding-in effect, exerted by natural resource dependence, on public education expenditure. Abundant natural resources can provide funds for education expenditure. The sample was further divided into eastern and central and western regions. The results indicate that the crowding-out effect of natural resource dependence only affects public education expenditure in the Eastern region, while the crowding-in effect of natural resource dependence on public education expenditure in the central and western regions. Research shows that the regional differences of crowding-out or crowding-in effect are very obvious, so the government should adopt transfer payment to promote balanced regional development. Better economic and social policies will help to translate wealth from natural resources into economic growth. Thus, a “resource blessing” may emerge to replace the “resource curse.” Fairly distributed and higher quality education will enhance human capital, thereby promoting economic growth from its current resource-driven pattern to a knowledge-driven pattern.
Show more [+] Less [-]Occurrence and ecological risk of pharmaceutical and personal care products in surface water of the Dongting Lake, China-during rainstorm period
2019
Wang, Yongqiang | Liu, Ying | Lu, Shaoyong | Liu, Xiaohui | Meng, Yuan | Zhang, Guodong | Zhang, Yaru | Wang, Weiliang | Guo, Xiaochun
The pharmaceutical and personal care product (PPCP) residues in freshwater lakes are being highlighted around the world. The occurrence and ecological risk of 34 PPCPs classified as antibiotics, non-steroidal anti-inflammatory drugs (NSAID), cardiovascular drugs, psychotropic drugs, anti-inflammatory drugs, psychostimulants, and pesticides during rainstorm period in surface water of the Dongting Lake, China, were studied. Twenty-six out of thirty-four PPCPs were detected, and the total concentrations of antibiotics ranged from 0.15 to 214.75 ng L⁻¹ in surface water. The highest average concentration was observed for diclofenac, followed by diethyltoluamide (DEET). The PPCP concentrations were much lower in Dongting Lake compared to other rivers and lakes due to the strong dilution effect of rainstorm, while the detection rate remains high. Caffeine and DEET were detected with 100% frequency in Dongting Lake, and the detection rates of diclofenac, mefenamic acid, and roxithromycin were above 90%. The pollution levels of antibiotics decreased in the order of East Dongting Lake > South Dongting Lake > West Dongting Lake, which may be related to the distribution of aquaculture plants, sewage treatment plants, and population density. The risk quotient (RQ) method was used to evaluate ecological environment risk under the worst case and the results suggested that clarithromycin, diclofenac, roxithromycin, and erythromycin might pose a significant risk to aquatic organisms in Dongting Lake, especially clarithromycin. This study can provide data support for further research on the dilutive effect and mechanism of rainwater runoff on PPCPs in lakes on a large scale.
Show more [+] Less [-]Characterization and chemical fixation of stainless steel pickling residue using sodium sulfide hydrate
2019
Su, Peidong | Li, Yang | Zhang, Junke | Li, Yadong
The stainless steel pickling residue (SSPR) produced from the stainless steel industries in China contains large amounts of heavy metals such as chromium (Cr) and nickel (Ni). The study found that the hexavalent chromium Cr (VI) was the primary contributor to the leaching of Cr in the toxicity character leaching test. A chemical fixation with sodium sulfide was used to treat the SSPR, and the response surface methodology (RSM) was employed to optimize the process. The results revealed that the sodium sulfide dose and curing time had significant effects on the fixation of Cr. The higher was the sodium sulfide dose, and the longer the curing time, the lower the leaching concentration of Cr would be. The water addition amount had insignificant effect when it was higher than 70%. A dose of 1.2% sodium sulfide on dry mass basis, a water addition of 90–100%, and a curing time of longer than 10 days in the open air could reduce the leaching of Cr to below the beneficial use threshold. The low chemical dose and simple procedures established in this study make this treatment method cost-effective for rendering the SSPR into a nonhazardous and useful material.
Show more [+] Less [-]Efficiency of sequential UV/H2O2 and biofilm process for the treatment of secondary effluent
2019
Yan, Peng-Fei | Yuan, Shoujun | Wang, Wei | Hu, Zhen-Hu | Mu, Yang | Yu, Han-Qing
In response to the shortage of water resources, multiple processes have been applied to turn wastewater secondary effluent (SE) into potable water. However, trace organic contaminants (TOrCs) and high concentrations of organic matter contained in SE pose a significant challenge to the reclamation. In this manuscript, combined UV-based and biofilm processes were used to treat the SE spiked with ibuprofen (IBU) and clofibric acid (CA). The efficiency of these sequential treatments was characterized in terms of changes in dissolved organic carbon (DOC), absorbance at 254 nm (A₂₅₄), fluorescence excitation-emission matrix (FEEM), the concentration of IBU and CA, and molecular weight of SE. Parallel factor (PARAFAC) was applied as the analysis method for FEEM of the samples and two fluorescent components were successfully identified: humic-like substances (C1) and protein-like matter (C2). Large reductions in A₂₅₄, C1, C2, IBU, and CA were observed during the UV-based processes, especially with the addition of H₂O₂. Nearly 50% of A₂₅₄, 80% of the component C1 were decreased and almost complete removal of the component C2 and TOrCs was achieved by UV/2.0 mM H₂O₂ after 90-min treatment. During the oxidation processes, the formation of lower molecular weight (LMW) compounds was detected, and the biodegradability of the organic matters was greatly increased. Although no significant DOC reduction was obtained in UV-based processes, an obvious further DOC reduction (30~60%) was achieved by biofilm treatment following UV-based processes, especially after UV/H₂O₂ treatments. In the meantime, large amounts of LMW were removed in the biofilm treatment process. This manuscript provides an effective advanced treatment of SE for the removal of DOC and TOrCs, facilitating the wastewater reclamation.
Show more [+] Less [-]Methylococcaceae are the dominant active aerobic methanotrophs in a Chinese tidal marsh
2019
Deng, Yongcui | Gui, Qian | Dumont, Marc | Han, Cheng | Deng, Huan | Yun, Juanli | Zhong, Wenhui
Although coastal marshes are net carbon sinks, they are net methane sources. Aerobic methanotrophs in coastal marsh soils are important methane consumers, but their activity and populations are poorly characterized. DNA stable-isotope probing followed by sequencing was used to determine how active methanotrophic populations differed in the main habitats of a Chinese coastal marsh. These habitats included mudflat, native plant-dominated, and alien plant-dominated habitats. Methylococcaceae was the most active methanotroph family across four habitats. Abundant methylotroph sequences, including methanotrophs and non-methane-oxidizing methylotrophs (Methylotenera and Methylophaga), constituted 50–70% of the 16S rRNA genes detected in the labeled native plant-dominated and mudflat soils. Methylotrophs were less abundant (~ 20%) in labeled alien plant-dominated soil, suggesting less methane assimilation into the target community or a different extent of carbon cross-feeding. Canonical correspondence analysis indicated a significant correlation between the active bacterial communities and soil properties (salinity, organic carbon, total nitrogen, pH, and available phosphorus). Importantly, these results highlight how changing vegetation or soil features in coastal marshes may change their resident active methanotrophic populations, which will further influence methane cycling.
Show more [+] Less [-]Phycoremediation of lithium ions from aqueous solutions using free and immobilized freshwater green alga Oocystis solitaria: mathematical modeling for bioprocess optimization
2019
El-Naggar, Noura El-Ahmady | Hamouda, Ragaa A. | Rabei, Nashwa H. | Mousa, Ibrahim E. | Abdel-Hamid, Marwa Salah
Lithium is registered as a serious pollutant that causes environmental damage to an irrigation water supply. Freshwater green alga (Oocystis solitaria) was studied for its potential to remove lithium ions from aqueous solutions. The Plackett–Burman design was applied for initial screening of six factors for their significances for the removal of lithium from aqueous solutions using Oocystis solitaria cells. Among the variables screened, pH, lithium concentration, and temperature were the most significant factors affecting lithium removal. Hence, the levels of these significant variables were further investigated for their interaction effects on lithium removal using the Box–Behnken statistical design. The optimum conditions for maximum lithium removal from aqueous solutions by Oocystis solitaria were the initial lithium concentration of 200 mg/L, contact time of 60 min, temperature of 30 °C, pH 5, and biomass of Oocystis solitaria cells of 1 g/L with agitation condition. Under the optimized conditions, the percentage of maximum lithium removal was 99.95% which is larger than the percentage of lithium removal recorded before applying the Plackett–Burman design (40.07%) by 2.49 times. The different properties of Oocystis solitaria, as an adsorbent, were explored with SEM and via FTIR analysis. The spectrum of FTIR analysis for samples of Oocystis solitaria cells before lithium biosorption showed different absorption peaks at 3394 cm⁻¹, 2068 cm⁻¹, 1638 cm⁻¹, 1398 cm⁻¹, 1071 cm⁻¹, and 649 cm⁻¹ which has been shifted to 3446 cm⁻¹, 2924 cm⁻¹, 1638 cm⁻¹, 1384 cm⁻¹, 1032 cm⁻¹, and 613 cm⁻¹, respectively, after lithium biosorption by the alga. The treatment of aqueous solution containing lithium with Oocystis solitaria cells immobilized in alginate beads removed 98.71% of lithium at an initial concentration of 200 mg/L after 5 h. Therefore, Oocystis solitaria may be considered as an alternative for sorption and removal of lithium ions from wastewaters.
Show more [+] Less [-]Elimination performance of methylene blue, methyl violet, and Nile blue from aqueous media using AC/CoFe2O4 as a recyclable magnetic composite
2019
Foroutan, Rauf | Muḥammadī, Riz̤ā | Ramavandi, Bahman
The present paper describes the sono-assisted adsorption (sono-adsorption) of methylene blue (MB), methyl violet (MV), and Nile blue (NB) from aqueous solution by AC/CoFe₂O₄ magnetic composite. FT-IR, TGA-DTG, VSM, XRD, TEM, SEM, EDX, Map, and Raman analysis were used to characterize the magnetic composite. The magnetization saturation value of AC/CoFe₂O₄ magnetic composite was determined to be 53.06 emu/g. Dye sono-adsorption efficiency was increased by increasing adsorbent dose, pH value, and contact time, but not dye concentration. Pseudo-first-order, pseudo-second-order, and intra-particle diffusion models were used to study the kinetic behavior of the cationic dye sono-adsorption. The sono-adsorption kinetics was reasonably followed by pseudo-second-order model (R² > 0.998). The results showed that the Freundlich model (R² > 0.976) was more able to describe the sono-adsorption equilibrium behavior than Langmuir, D-R, and Scatchard models. The maximum sono-adsorption capacity of NB, MV, and MB was determined as 86.24, 83.90, and 87.48 mg/g, respectively. Based on the parameters derived from isotherm modeling (RL, n, and E), the sono-adsorption process of cationic dyes is desirable and physical. An increase in NaCl concentration reduced the sono-adsorption efficiency for all dyes. Also, the adsorption-desorption of AC/CoFe₂O₄ magnetic was studied up to 10 stages, and it was confirmed that the sono-adsorption efficiency is acceptable up to the eight stage. AC/CoFe₂O₄ magnetic composite is, therefore, an affordable and recyclable adsorbent to remove the molecule of NB, MV, and MB dyes from aqueous media.
Show more [+] Less [-]Towards integrating toxicity characterization into environmental studies: case study of bromine in soils
2019
Bratec, Tatiana | Kirchhübel, Nienke | Baranovskaya, Natalia | Laratte, Bertrand | Jolliet, Olivier | Rikhvanov, Leonid | Fantke, Peter
Pollution from bromine and some of its related compounds is currently unregulated in soil from Russia and other countries, and tools for sound assessment of environmental impacts of bromine contamination are largely missing. Hence, assessing potential implications for humans and ecosystems of bromine soil contamination is urgently needed, which requires the combination of measured soil concentrations from environmental studies and quantified potential toxicity impacts. To address this need, we used data from an experimental study assessing bromine in soils (384 samples) of Tomsk oblast, Russia, starting from measured concentrations obtained by Instrumental Neutron Activation Analysis in an earlier study. From these data, we calculated the bromine mass in soils and used these as starting point to characterize related cumulative impacts on human health and ecosystems in the Tomsk region, using a global scientific consensus model for screening-level comparative toxicity characterization of chemical emissions. Results show that the combination of sampling methodology with toxicity characterization techniques presents a new approach to be used in environmental studies aimed at environmental assessment and analysis of a territory. Our results indicate that it is important to account for substance-specific chemical reaction pathways and transfer processes, as well as to consider region-specific environmental characteristics. Our approach will help complement environmental assessment results with environmental sustainability elements, to consider potential tradeoffs in impacts, related to soil pollution, in support of improved emission and pollution reduction strategies.
Show more [+] Less [-]Metal content in the liver, kidney, and feathers of Northern gannets, Morus bassanus, sampled on the Spanish coast
2019
Nardiello, Veronica | Fidalgo, Luis Eusebio | López-Beceiro, Ana | Bertero, Alessia | Martínez-Morcillo, Salomé | Míguez, María Prado | Soler, Francisco | Caloni, Francesca | Pérez-López, Marcos
The value of birds as bioindicators for monitoring the environmental inorganic elements has been globally recognized. In this context, due to its well-known ecology and population stability, the Northern gannet (Morus bassanus) could be particularly useful. Dead Northern gannets (n = 30) were collected and samples from the liver, kidney, and feathers were taken, dried, mineralized, and finally analyzed via ICP-MS. Metals and metalloids, namely As, Cd, Hg, Pb, and Zn, associated with environmental pollution and toxicity on living organisms, were evaluated. The mean highest concentrations of As, Hg, and Zn were found in the liver (0.916, 7.026, and 89.81 mg/kg dry weight, respectively). For Cd, the kidney showed the highest mean concentration (17.51 mg/kg dry weight), whereas for Pb, this value corresponded to the feathers (0.399 mg/kg dry weight). Significant differences were found between the age classes in terms of contaminant concentrations, with the adults exhibiting higher metal levels. This difference was significantly relevant for Pb and Hg, where the effect of age was observed for all the considered tissues. When considering the effect of gender, no significant differences were observed, in agreement with similar studies performed in other geographical regions. Finally, positive correlations between the concentrations of Hg and Pb in the feathers and in the liver (r = 0.688, p < 0.001 and r = 0.566, p < 0.001, respectively) were observed, as well as between the feather and kidney concentrations (r = 0.685, p < 0.001) indicating the possibility to use feathers, a non-invasive biomonitoring tissue, for better understanding Hg and Pb exposure in seabirds.
Show more [+] Less [-]Process optimization via response surface methodology in the physico-chemical treatment of vegetable oil refinery wastewater
2019
Louhıchı, Ghofrane | Bousselmı, Latifa | Ghrabı, Ahmed | Khounı, Imen
The present paper investigates the efficiency of coagulation/flocculation process using aluminum sulfate as coagulant and CHT industrial flocculent as coagulant aid/flocculent in the treatment of vegetable oil refinery wastewater (VORW). The process optimization was conducted in two steps, jar test experiments for preliminary evaluation to identify the most influencing factors and response surface methodology using Box–Behnken design to investigate the effects of three major factors and their interactions. The variables involved were the coagulant concentration (X₁), flocculent dosage (X₂), and initial pH (X₃) of water samples, while the responses were COD removal (Y1) and residual turbidity (Y2). The optimal conditions obtained by solving the quadratic regression models, as well as by analyzing the response surface contour plots, were as follows: 2.4 g/L of coagulant (aluminum sulfate), 60.05 mg/L of flocculent, and about 9.23 as initial pH. Under these conditions, the coagulation/flocculation treatment was able to achieve 99% of COD removal with total turbidity elimination (100% removal). Analysis of variance showed high variance coefficient (R²) values of 0.929 and 0.836 for COD and turbidity removals, respectively, thus ensuring a satisfactory adjustment of the second-order regression model with the experimental data. This statistical design methodology was demonstrated as an efficient and feasible approach for the optimization of coagulation/flocculation treatment.
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