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Evaluation of the Stone and Marble Industry in Palestine: environmental, geological, health, socioeconomic, cultural, and legal perspectives, in view of sustainable development 全文
2021
Salem, Hilmi S.
The Stone (limestone) and Marble (trade name) Industry (SMI) is one of the most important and active industries in Palestine, as being economically and financially rewarding and greatly beneficial to the public and private sectors. This industry, which employs about 15,000–20,000 workers, contributes 20–25% to the total industrial revenues of Palestine, and 4.5% to the total gross national product. Despite its benefits, SMI has adverse effects on public health, the environment, biodiversity, water systems (both surface and underground), green cover, and ecosystems in general, as it is considered one of the most air- water-, soil-, and noise-polluting sources. To achieve the purpose of this research paper, available data and literature are analyzed, evaluated, and used, in order to provide a comprehensive understanding of the status of SMI, in light of sustainable development. This relates to various perspectives, including limestone geology, geopolitics, socioeconomics, culture, technology, legislation, as well as climate change, acid rain, and harmful effects of the SMI scale on public health and safety, environmental well-being, and challenges facing the industry. Two field studies, carried out in northern and southern West Bank, dealing with particulate matter (PM₁, PM₂.₅, PM₇, PM₁₀, and TSP) and environmental pollution, were analyzed, and their results were compared with each other, as well as with the World Health Organization’s (WHO) guidelines. It is found that both West Bank’s areas are heavily polluted, resulting in considerable adverse impacts on public health, the environment, and green cover. Based on the findings of this paper, it is recommended that SMI should properly adhere to WHO guidelines and international standards to make the industry safer and more durable and sustainable, with fewer negative impacts on public health, the environment, and green cover.
显示更多 [+] 显示较少 [-]Improving the performance of vertical flow constructed wetlands by modifying the filtering media structure 全文
2021
Carballeira, Tania | Ruiz, Isabel | Soto, Manuel
The aim of this research was to study the influence of the bed media configuration and particle size on the treatment efficiency of subsurface vertical flow (VF) constructed wetlands (CWs) treating municipal wastewater. Two outdoor pilot units (VF1 and VF2, planted with Phragmites australis) with the configuration C1 were operated in parallel for 2 years at similar surface loading rates of 9.7 ± 3.2 (VF1) and 10.1 ± 3.3 (VF2) g biological oxygen demand (BOD₅)/m²·day (19.5 ± 6.4 (VF1) and 20.4 ± 6.2 (VF2) g chemical oxygen demand (COD)/m²·day). A different configuration C2 was used during the third year at 16.9 ± 4.6 (VF1) and 18.2 ± 3.0 (VF2) g BOD₅/m²·day and 26.0 ± 7.2 (VF1) and 28.0 ± 4.7 (VF2) g COD/m²·day. Two different filtering materials (1–3-mm sand for VF1 and 2–6-mm fine gravel for VF2) were used for configuration C1. The same units were modified after 2 years of operation by adding a 10-cm layer of fine sand (0–2 mm) on the top (configuration C2). In C1 conditions, the unit with the coarse material VF2 showed significantly (p < 0.05) lower removal efficiencies of total suspended solids (TSS) and BOD₅ than VF1, and both units failed to meet the BOD₅ discharge limit. In C2 conditions, removal efficiencies reached 82% TSS, 97% BOD₅, 76–81% ammonia, and 60–66% TN, without significant differences between VF1 and VF2 units. Removal efficiencies were significantly higher for configuration C2 than that for C1, due to the positive effect of the upper fine sand layer. The presence of this fine sand layer doubled the water retention time and increased the removal rates, while the infiltration rates were high enough for an operation free of clogging.
显示更多 [+] 显示较少 [-]Synergistic removal of particles, SO2, and NO2 in desulfurized flue gas during condensation 全文
2021
Zhang, Hao | Dong, Yong | Lai, Yanhua | Zhang, Hao | Zhang, Xinbo
The synergistic removal of multi-pollutants, including particles, SO₂, and NO₂, is a key concern in the process of flue gas purification, during which the supersaturated environment is an essential premise for the nucleation and deep reduction of particles. The condensation of desulfurized flue gas using heat exchangers can not only recover condensed water and latent heat but also create supersaturated environment to promote the flue gas purification. In this study, an experimental system for desulfurized flue gas condensation is established. The effect and associated mechanism of condensation process on the removal of multi-pollutions are clarified. The results show that particles with an aerodynamic diameter larger than 2.5 μm accounts for 50% in mass proportion. The flue gas temperature drop has positive influence to the increase of the ideal supersaturation degree, which is beneficial for the removal of particles (especially when the aerodynamic diameter is less than 1 μm), SO₂, and NO₂. The ideal supersaturation degree slightly reduces with the rise of inlet flue gas temperature, which can promote the removal efficiency of small particles, while weaken that of large particles, SO₂, and NO₂. Caused by the increase of flue gas flow rate, the nucleation process weakens, reducing the removal efficiency of all pollutants (particles, 45.2–28.3%; SO₂, 27.5–14.5%; NO₂, 21.5–15%). On the whole, the increase of the ideal supersaturation degree contributes to the synergistic removal of pollutants especially particles with smaller radius in the flue gas. The reduction of particles with aerodynamic diameter less than 1 μm is conductive to the synergistic removal of SO₂ and NO₂.
显示更多 [+] 显示较少 [-]Efficient simultaneous removal of heavy metals and polychlorobiphenyls from a polluted industrial site by washing the soil with natural humic surfactants 全文
2021
Piccolo, Alessandro | De Martino, Antonio | Scognamiglio, Francesco | Ricci, Roberto | Spaccini, Riccardo
We evaluated the effectiveness of natural organic surfactants such as humic acids (HA) from lignite to simultaneously wash heavy metals (HM) and polychlorobiphenyls (PCB) from a heavily contaminated industrial soil of northern Italy. Supramolecular HA promote in solution a micelle-like structure, where recalcitrant apolar organic xenobiotics are repartitioned from surfaces of soil particles during soil washing process. Concomitantly, the HA acidic functional groups enable a simultaneous complexation of HM. A single soil washing with HA removed 68 and 75% of PCB congeners for 1:1 and 10:1 solution/soil ratios, respectively. The same HA washing simultaneously and efficiently removed a cumulative average of 47% of total HM, with a maximum of 57 and 67% for Hg and Cu, respectively. We showed that washing a highly polluted soil with HA solution not only is an effective and rapid soil remediation technique but also simultaneously removes both HM and persistent organic pollutants (POP). Soil washing by humic biosurfactants is also a sustainable and eco-friendly technology, since, contrary to synthetic surfactants and solvents used in conventional washing techniques, it preserves soil biodiversity, promotes natural attenuation of unextracted POP, and accelerates further soil reclamation techniques such as bio- or phytoremediation.
显示更多 [+] 显示较少 [-]The effects of inflow of agricultural biogas digestate on bivalves’ behavior 全文
2021
Mbah, Jasper Tembeck | Chmist-Sikorska, Joanna | Szoszkiewicz, Krzysztof | Czekała, Wojciech
This study focused on the reaction of bivalve molluscs to biogas digestate, which is a waste product of an increasingly developing biogas production in rural areas worldwide. The effects of biogas digestate on aquatic organisms are not fully known, and neither this substance nor any types of manure were tested in the monitoring based on valvometry, which is a biomonitoring method based on bivalve behavior. The change in bivalves functioning in biogas digestate inflow was studied using three different diluted digestate concentrations. Exposure to the highest concentration of digestate induced a decline of mean shell opening and activity time of Unio tumidus species. A significant difference in behavioral patterns was recorded during the first 10 min after exposure to the digestate. A Gradual decreasing tendency of shell opening levels was apparent under the highest concentration reaching 55% compared to the pretreatment value. Also, a decreasing tendency was observed under the medium concentration (82.4% of initial level) after 2 h, while an increase in shell opening levels was recorded in the most diluted digestate. This research work proved that the inflow of biogas digestate has significant impact on bivalves’ behavior. Unio tumidus is a sensitive indicator of biogas digestate inflow in the aquatic environment. Moreover, it proved that the opening and closing activities over time depend on the concentration of the digestate. Therefore, the mollusk bivalves might be utilized in early warning systems to detect organic pollutants in water.
显示更多 [+] 显示较少 [-]Toward ecological function zoning and comparison to the Ecological Redline Policy: a case study in the Poyang Lake Region, China 全文
2021
Xu, Chen | Yang, Guishan | Wan, Rongrong | Ou, Weixin | Wang, Peng
Faced with huge environmental problems of ecosystem degradation, “Ecological Redline Policy (ERP)” in China is a new key national-level policy to manage different land use functions in accordance with development and environmental limits. As the water–land complex ecosystem with the largest freshwater lake, wetland natural reserves and ecological importance in China, Poyang Lake Region (PLR) is selected to quantify and map multiple ecosystem services, investigate the ecological function zoning as part of research on ecological zoning control and major ecological source areas to illustrate and address the implementation of this strategy based on the importance and vulnerability analysis of ecosystem services. According to ecological function zoning results, extremely important, highly important, medium important and important zones respectively account for 26.1%, 28.1%, 17.4% and 28.4% of the total area. With an area of 5422.2 km², the extremely important zone is 1010.6 km² larger than the ERP. Moreover, 81.6% of the ERP is located in the extremely important zone. By discussing the implications and applications of ecological management, this study contributes to the ecological protection of Poyang Lake and provides a foundation for research on ecological function zoning at the regional scale.
显示更多 [+] 显示较少 [-]A study on water quality prediction by a hybrid CNN-LSTM model with attention mechanism 全文
2021
Atwill, Yurong Y. | Xiong, Qingyu | Wu, Chao | Zou, Qinghong | Yu, Yang | Yi, Hualing | Gao, Min
The water environment plays an essential role in the mangrove wetland ecosystem. Predicting water quality will help us better protect water resources from pollution, allowing the mangrove ecosystem to perform its normal ecological role. New approaches to solve such nonlinear problems need further research since the complexity of water quality data and they are easily affected by the noise. In this paper, we propose a water quality prediction model named CNN-LSTM with Attention (CLA) to predict the water quality variables. We conduct a case study on the water quality dataset of Beilun Estuary to predict pH and NH₃-N. Linear interpolation and wavelet techniques are used for missing data filling and data denoising, respectively. The hybrid model CNN-LSTM is highly capable of resolving nonlinear time series prediction problems, and the attention mechanism captures longer time dependence. The experimental results show that our model outperforms other ones, and can predict with different time lags in a stable manner.
显示更多 [+] 显示较少 [-]Catalytic activity comparison of natural ferrous minerals in photo-Fenton oxidation for tertiary treatment of dyeing wastewater 全文
2021
Lu, Jun | Chen, Quanyuan | Zhao, Qi | Liu, Xiaochen | Zhou, Juan
Natural ferrous minerals are readily available and recyclable catalysts in photo-Fenton-like oxidation for wastewater treatment. In this work, typical ferrous oxide and sulfide minerals including magnetite, chalcopyrite, and pyrrhotite were exploited as catalysts in heterogeneous photo-Fenton oxidation for purification of biological effluent of dyeing wastewater. In a wide initial pH range (3.0~7.5), ferrous mineral-based heterogeneous photo-Fenton-like reactions were proven to be effective on the oxidation of recalcitrant pollutants. COD removals achieved 60.57%, 58.83%, and 57.41% using pyrrhotite, chalcopyrite, and magnetite, respectively, as catalyst under ultraviolet irradiation of 220~275 nm at H₂O₂ concentration of 9.8 mM. The corresponding COD removals were 51.75% and 34.09% with or without ferrous sulfate additions in UV/H₂O₂ systems. Minerals exhibited excellent stability and reusability with photo-catalytic activity reduction of less than 10% in the reuse of 5 cycles. Dissolved iron concentrations were determined to be 1.86 mg L⁻¹, 4.62 mg L⁻¹, and 7.53 mg L⁻¹ for magnetite, chalcopyrite, and pyrrhotite, respectively, at pH 3 and decreased to zero in neutral pH environment, which were much lower than those required for homogenous Fenton reaction. It was deduced that oxidation of recalcitrant pollutants was mainly catalyzed by Fe(II) on the mineral surface. The more reactive oxygen species such as hydroxyl radicals were resulted from the reaction of surface Fe (II) with H₂O₂, H₂O₂ photolysis, and charge separation of minerals under UV irradiation.
显示更多 [+] 显示较少 [-]Does the new-type urbanization construction improve the efficiency of agricultural green water utilization in the Yangtze River Economic Belt? 全文
2021
Ding, Xuhui | Cai, Zhongyao | Fu, Zhu
It is very important to control agricultural water pollution and promote agricultural water saving, for high-quality development of Yangtze River Economic Belt (YREB). The efficiency of agricultural green water utilization (EAGWU) needs financial and technical support from the new-type urbanization, which also change agricultural production mode and resource utilization level. This paper introduces non-point source water pollution into the output, adopts the super efficiency-slack model (SE-SBM) to measure the EAGWU, and uses difference generalized method of moments (DIF-GMM) to examine how new-type urbanization affects EAGWU from its four core characteristics. The results of EAGWU show that the overall efficiency value has been increasing rapidly in the research period, while the eastern provinces performed better and the central provinces performed worse. On the other hand, the overall difference in EAGWU first diverged and then shrunk, while economically developed provinces has been converging all the time. The results of driving factor estimation show that population urbanization has a significantly positive effect on EAGWU, with the rural labor force transfer and agricultural land circulation. Economic urbanization and urban-rural integration have negative effects, with the widening gap of absolute income and the compressed space of agricultural development. The EAGWU lag phase has a positive effect, because of the ratchet or cumulative effect, while equilibrium-urbanization has an insignificant effect. The conclusions will provide preferable recommendations for decision-making of green and water-saving development in agriculture.
显示更多 [+] 显示较少 [-]Iron, thermal stratification, Eucalyptus sp., and hypoxia: drivers to water blackening in southern China reservoirs 全文
2021
Li, Yiping | Norgbey, Eyram | Zhu, Ya | Nwankwegu, Amechi S. | Bofah-Buoh, Robert | Anim, Desmond | Takyi- Annan, Georgina Esi | Nuamah, Linda | Banahene, Patrick | Pu, Yashui | Huang, Yanan
The management of black water depends primarily on the knowledge of the dynamics of organic matter (OM), iron (Fe), sulfide (S), and manganese (Mn), at the water-sediment boundary (WSB). However, the mechanistic path of these substances leading to black water remains unsettled. In this study, a 35-day field study was conducted using the thin-film diffusion gradient technology (DGT) and the planar optrode to address the unknown combined effects of Fe, Mn, OM, S, and tannins from Eucalyptus species on Tianbao reservoir.Our results indicated that the hypolimnion was hypoxic due to thermal stratification, which caused the reduction of insoluble Fe and Mn from sediments to bottom water. Correlation analysis (Fe:S (r:0.5–0.9); Mn:S (r:0.2–0.8)) and elevated fluxes (Fe²⁺, Mn²⁺, S²⁻) connoted that these parameters interacted chemically to give black matter. The content of OM, Fe²⁺, and tannic acid in the benthic region diminished remarkably (p < 0.05) from day 1 (strong stratification) to day 35 (weak stratification), connoting that these parameters also interacted chemically to give black matter. The turbidity (clarity of the water) increased from day 1 to 35 with a significant difference (p < 0.05) recorded on day 14 confirming that black water was formed on this day when the thermal structure of the reservoir was annihilated. Correlation analysis supported the assertion that the variability in oxygen and redox conditions caused changes in Fe, Mn, and OM content at the WSB.The finding from the field research provides useful information to stakeholders on how to improve the quality of freshwater management designs.
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