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Assessing climate change impacts on pearl millet under arid and semi-arid environments using CSM-CERES-Millet model
2019
Ullah, Asmat | Ahmad, Ishfaq | Ashfaq, Ahmad | Khaliq, Tasneem | Saeed, Umer | M. Habib-ur-Rahman, | Hussain, Jamshad | Ullah, Shafqat | Hoogenboom, Gerrit
Climate change adversely affects food security all over the world, especially in developing countries where the increasing population is confronting food insecurity and malnutrition. Crop models can assist stakeholders for assessment of climate change in current and future agricultural production systems. The aim of this study was to use of system analysis approach through CSM-CERES-Millet model to quantify climate change and its impact on pearl millet under arid and semi-arid climatic conditions of Punjab, Pakistan. Calibration and evaluation of CERES-Millet were performed with the field observations for pearl millet hybrid 86M86. Mid-century (2040–2069) climate change scenarios for representative concentration pathway (RCP) 4.5 and RCP 8.5 were generated based on an ensemble of selected five general circulation models (GCMs). The model was calibrated with optimum treatment (15-cm plant spacing and 200 kg N ha⁻¹) using field observations on phenology, growth and grain yield. Thereafter, pearl millet cultivar was evaluated with remaining treatments of plant spacing and nitrogen during 2015 and 2016 in Faisalabad and Layyah. The CERES-Millet model was calibrated very well and predicted the grain yield with 1.14% error. Model valuation results showed that there was a close agreement between the observed and simulated values of grain yield with RMSE ranging from 172 to 193 kg ha⁻¹. The results of future climate scenarios revealed that there would be an increase in Tₘᵢₙ (2.8 °C and 2.9 °C, respectively, for the semi-arid and arid environment) and Tₘₐₓ (2.5 °C and 2.7 °C, respectively, for the semi-arid and arid environment) under RCP4.5. For RCP8.5, there would be an increase of 4 °C in Tₘᵢₙ for the semi-arid and arid environment and an increase of 3.7 °C and 3.9 °C in Tₘₐₓ, respectively, for the semi-arid and arid environment. The impacts of climate changes showed that pearl millet yield would be reduced by 7 to 10% under RCPs 4.5 and 8.5 in Faisalabad and 10 to 13% in Layyah under RCP 4.5 and 8.5 for mid-century. So, CSM-CERES-Millet is a useful tool in assessing the climate change impacts.
显示更多 [+] 显示较少 [-]Environmental impact of the on-road transportation distance and product volume from farm to a fresh food distribution center: a case study in Brazil
2019
Duarte, Gilson Tristão | de Alencar Nääs, Irenilza | Innocencio, Cláudio Monico | da Silva Cordeiro, Alexandra Ferreira | da Silva, Raquel Baracat Tosi Rodrigues
The pollutants’ emissions from on-road transport are critical pressure on the climate change scenario, and most developing countries rely on mostly diesel transportation. The current study aimed to estimate the environmental impact of the distance from the agricultural production area of fresh food (papaya, potato, and tomato) to a fresh food distribution center located in Campinas, Sao Paulo, Brazil. The way the products were carried was assessed for calculating the total transported volume. The total amount carried was measured, considering the number of trips multiplied by the total distance traveled within a year of supply. An online calculator was used to evaluate the amount of CO₂ emission, and to allow the estimative of the amount of CO₂-eq, that is the Global Warming Impact (GWP) in 100 years. The highest CO₂ emission was identified in the potato transported from Paraná State to the distribution center, with a CO₂-eq emission of 3237 t/year (64% of contribution), followed by the papaya from Bahia State (2723 t/year, 42% of contribution), and the tomato from Sao Paulo State (625 t/year, 71% of contribution). However, when computing the GWP, the highest value was found in the transport of potato from the Minas Gerais State (8 × 10⁻² in 100 years) followed by the papaya from Rio Grande do Norte State (5 × 10⁻² in 100 years) and the papaya from Bahia (3 × 10⁻² in 100 years). The higher the amount of product transported by a trip, the smaller the environmental impact in the long run. A proper strategy to reduce the environmental impact would be to have large freight volume when transporting food from vast distances within continental countries.
显示更多 [+] 显示较少 [-]Role of organic fouling layer on the rejection of trace organic solutes by nanofiltration: mechanisms and implications
2019
Gan, Zhendong | Du, Xing | Zhu, Xuewu | Cheng, Xiaoxiang | Li, Guibai | Liang, Heng
To investigate how the organic fouling layers on nanofiltration (NF) membrane surface and the strong matrix effect (particularly by Ca²⁺) influence the rejection of trace organic compounds (TOrCs), filtration experiments with two TOrCs, bisphenol A (BPA) and sulfamethazine (SMT), were carried out with virgin and organic-fouled NF membrane. Organic fouling layer on the membrane was induced by sodium alginate (SA) at different concentrations of Ca²⁺. The results indicated that NF membrane maintained consistently rejection of TOrCs with little influence by membrane fouling at lower Ca²⁺ concentration. In contrast, organic fouling caused at higher concentration of Ca²⁺ observably restrained the rejections of both BPA and SMT. Furthermore, based on the cake-enhanced concentration polarization (CECP) model, the rejection of TOrCs was divided to the real rejection and the mass transfer coefficient. Moreover, it was found that the decrease in rejection resulted by organic fouling was due to the real rejection that was restrained by fouling layer with irregular impact on the mass transfer coefficient. Although the mechanism of trace compounds rejection was complex, the controlling factors varied among foulants. Nevertheless, the steric effect of the cake layer played an important role in determining solute rejection by organic-fouled NF membrane.
显示更多 [+] 显示较少 [-]Pollutants from fish feeding recycled for microalgae production as sustainable, renewable and valuable products
2019
Chan, Hing
Trash fish feeding of cage fish can result in marine pollution. Whole and chopped trash fish can leach pollutants such as ammonia, phosphate and protein into surrounding waters. Reduction of pollution can be achieved by recycling the wastewater generated from trash fish feeding for cultivation of microalgae. Microalgae are potent candidates for the production of renewable and sustainable products such as feed and food, health and pharmaceutical, cosmeceutical, industrial products, and biofuel. Two microalgae, Chlorella saccharophila and Nannochloropsis sp., have the potential to produce high amounts of polyunsaturated fatty acids. Furthermore, high oil content ranging from 10.7 to 13.6% is found in Chlorella saccharophila and up to 9.3% for Nannochloropsis sp. Moreover, these microalgae can also be utilized as a biofuel to give a mean calorific value of 5364 Cal/g which is higher than that of wood for Chlorella saccharophila and 6132 Cal/g which is equivalent to that of coal for Nannochloropsis sp. An alternative biofuel derived from microalgae is feasible due to the fact that they do not compete for arable land for cultivation and land crops for feed and food. This study discusses the synergistic coupling of microalgae mass production with wastewater treatment and carbon sequestration potential for mitigation of environmental impacts and a technically viable alternative energy resource. Additionally, the de-oiled biomass byproduct after oil extraction or its whole biomass can be converted into sustainable and renewal industrial products such as bioplastic, biopaint, bioasphalt, and biobuilding components.
显示更多 [+] 显示较少 [-]Distinctive impact of polystyrene nano-spherules as an emergent pollutant toward the environment
2019
Mishra, Prabhakar | Vinayagam, Saranya | Duraisamy, Kuppendran | Patil, Shrigouri Ravindrakumar | Godbole, Jueelee | Mohan, Alina | Mukherjee, Amitava | Chandrasekaran, Natarajan
The increasing load of nanoplastic pollution in the environment has become a major concern toward human and environmental safety. The current investigation mainly focused on assessing the toxic behavior of nanoplastics (polystyrene nano-spheres (PNS)) toward blood cells and marine crustacean. The study also investigated the temporal stability of PNS under different water matrices and its size-dependent sedimentation behavior in the sea water dispersion. The nano-dispersion showed mean particle size of 561.4 ± 0.80 and 613.7 ± 0.11 nm for PNS 1 and 781.4 ± 0.80 and 913.7 ± 0.11 nm for PNS 2 in lake and seawater, respectively after 48-h incubation, which is ~ 8-fold increase from its original size. The LC50 value against Artemia salina and lymphocytes were found to be 4.82 and 8.79 μg/mL, and 75 μg/mL, respectively for PNS 1 and PNS 2. The genotoxic study reveals that around 50% of lymphocytes were affected by both PNS at 50 μg/mL concentration, whereas the cytotoxic studies on RBC and lymphocytes showed 50% toxicity only at 100 μg/mL concentration. The genotoxic study displayed numerous tri- and multi-nucleated cells. The biochemical profile of A. salina exposed to lethal concentration demonstrated a significant decrease in the total protein, reduced glutathione, and catalase activity and increase in lipid peroxidation activity as a result of PNS permeation to tissues. In conclusion, the present study demonstrated that the polystyrene nano-spheres are emerging pollutant in the environment and are hazardous to humans.
显示更多 [+] 显示较少 [-]Analysis of swale factors implicated in pollutant removal efficiency using a swale database
2019
Fardel, Alexandre | Peyneau, Pierre-Emmanuel | Béchet, Béatrice | Lakel, Abdelkader | Rodriguez, Fabrice
Swales are traditional basic open-drainage systems which are able to remove stormwater-borne pollutants. In spite of numerous case studies devoted to their performances, parameters influencing the reduction of pollutant concentrations by swales remain elusive. In order to better characterize them, a database was set up by collecting performance results and design characteristics from 59 swales reported in the literature. Investigations on correlations among pollutant efficiency ratios (ERs) indicated that total trace metals (copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb)), total suspended solids (TSS), total phosphorus (TP), and total Kjeldahl nitrogen (TKN) exhibited many cross-correlated ERs. High ERs were observed for pollutants including a particulate form such as TSS (median ERs = 56%) and total trace metals (median ERs ≥ 62%), suggesting that these pollutants are efficiently trapped by sedimentation in swale bed and/or filtered within swale soil. Medium to high ERs were found for dissolved trace metals (median ERs ≥ 44%), whereas ERs for nutrient species were lower (median ERs ≤ 30%). The inflow concentration was identified as a major factor correlated to ER for most pollutants. For some pollutants, there is also a trend to get higher ER when the geometrical design of the swale increases the hydraulic residence time. Overall, this database may help to better understand swale systems and to optimize their design for improving pollutant removal.
显示更多 [+] 显示较少 [-]Increase of global DNA methylation patterns in beauty salon workers exposed to low levels of formaldehyde
2019
Barbosa, Eduardo | dos Santos, Ana Laura Anibaletto | Peteffi, Giovana Piva | Schneider, Anelise | Müller, Diana | Rovaris, Diego | Bau, Claiton Henrique Dotto | Linden, Rafael | Antunes, Marina Venzon | Charão, Mariele Feiffer
Formaldehyde (FA) is a carcinogenic aldehyde illegally added to creams as a hair straightening agent for the Brazilian blowout (BB). This study aimed to investigate the possible effects of occupational exposure to FA on global DNA methylation in salon workers with different exposure levels. FA exposure was monitored using environmental and biological measurements. The study included 49 salon workers divided by FA levels in the workplace into group A (FA < 0.01 ppm; n = 8), group B (0.03 ppm < FA < 0.06 ppm; n = 15), and group C (0.08 ppm < FA < 0.24 ppm; n = 26). The global DNA methylation levels were 3.12%, 4.55%, and 4.29% for groups A, B, and C, respectively, with statistically higher values for groups B and C compared to group A (p = 0.002). A correlation was found between FA in passive samplers and global DNA methylation (rₛ = 0.307, p = 0.032). Additionally, when only taking into account the hairdressers that performed the BB on clients instead of the whole group, a stronger correlation was observed between FA in personal passive samplers and global DNA methylation (rₛ = 0.764, p = 0.006). For the first time, an increase in DNA methylation was observed in subjects occupationally exposed to FA. In conclusion, our results indicated that even low levels of FA exposure could cause a disturbance in DNA methylation, leading to epigenetic changes, which is associated with cancer development. These data suggest a possible contribution of FA to cancer development through occupational exposure.
显示更多 [+] 显示较少 [-]The sedimentary record of polycyclic aromatic hydrocarbons in Yamzho Yumco Lake: evolution of local sources and adsorption dynamic in the Tibetan Plateau
2019
Wang, Qi | Li, Jun | Duan, Xu-Chuan | Yuan, Guo-Li | Fang, Bin | Wang, An-Ting
With the rapid increase in anthropogenic activities, the local emissions of polycyclic aromatic hydrocarbons (PAHs) in background regions, such as the Tibetan Plateau (TP), have attracted great attention. The deposition of PAHs in lake sediments provides a historical evolutionary record of such compounds in these regions. To investigate the evolution of PAHs in the TP, two sedimentary cores from Yamzho Yumco Lake were collected and dated at high resolution, and the concentrations of 16 PAHs and sediment properties were also analyzed. The total concentrations of the 16 PAHs ranged from 6.52 to 57.97 ng/g (dry weight) in YC1 and from 0.91 to 4.57 ng/g (dry weight) in YC2. According to the methods of principal component analysis (PCA) followed by multilinear regression analysis (MLRA), four sources of PAHs in the sediments were qualitatively and quantitatively identified, such as petroleum combustion, petrogenic, coal combustion, and biomass burning. Thus, the historical evolution of PAHs was summarized. In addition, the transported distance from local PAH emission sources was found to greatly affect the composition and concentration of PAHs in sites YC1 and YC2. Specifically, local sources contributed a greater proportion of heavy molecular weight (HMW) PAHs in YC1 and a higher proportion of light-molecular-weight (LMW) PAHs in YC2. Moreover, fine particles (size < 20 μm) were found to play a significant role in adsorbing PAHs in sediments. Furthermore, ∑₁₆PAHs in sediments were linearly correlated with the percentage of fine particles (size < 20 μm). This study provides a first example to investigate the historical evolution of PAH local emission in background regions by using lake sedimentary records, especially in the TP. Specifically, different local sources were identified using the methods of PCA followed by MLRA, and PAHs in TP sediments were predominantly adsorbed by fine particles rather than by total organic carbon (TOC) because the amount of TOC was limited.
显示更多 [+] 显示较少 [-]Comparative efficiency of peanut shell and peanut shell biochar for removal of arsenic from water
2019
Sattar, Muhammad Sohail | Shakoor, Muhammad Bilal | Ali, Shafaqat | Rizwan, Muhammad | Niazi, Nabeel Khan | Jilani, Asim
Contamination of surface water and groundwater streams with carcinogenic chemicals such as arsenic (As) has been a major environmental issue worldwide, and requires significant attention to develop new and low-cost sorbents to treat As-polluted water. In the current study, arsenite (As(III)) and arsenate (As(V)) removal efficiency of peanut shell biochar (PSB) was compared with peanut shell (PS) in aqueous solutions. Sorption experiments showed that PSB possessed relatively higher As removal efficiency than PS, with 95% As(III) (at pH 7.2) and 99% As(V) (at pH 6.2) with 0.6 g L⁻¹ sorbent dose, 5 mg L⁻¹ initial As concentration, and 2 h equilibrium time. Experimental data followed a pseudo-second-order model for sorption kinetics showing the dominance of chemical interactions (surface complexation) between As and surface functional groups. The Langmuir model for sorption isotherm indicated that As was sorbed via a monolayer sorption process. The X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy analyses revealed that the hydroxyl (–OH) and aromatic surface functional (C=O, C=C–C, and –C–H) groups contributed significantly in the sorption of both As species from aqueous solutions through surface complexation and/or electrostatic reactions. We demonstrate that the pyrolysis of abandoned PS yields a novel, low-cost, and efficient biochar which provides dual benefits of As-rich water treatment and a value-added sustainable strategy for solid waste disposal.
显示更多 [+] 显示较少 [-]The use of fast molecular descriptors and artificial neural networks approach in organochlorine compounds electron ionization mass spectra classification
2019
Przybyłek, Maciej | Studziński, Waldemar | Gackowska, Alicja | Gaca, Jerzy
Developing of theoretical tools can be very helpful for supporting new pollutant detection. Nowadays, a combination of mass spectrometry and chromatographic techniques are the most basic environmental monitoring methods. In this paper, two organochlorine compound mass spectra classification systems were proposed. The classification models were developed within the framework of artificial neural networks (ANNs) and fast 1D and 2D molecular descriptor calculations. Based on the intensities of two characteristic MS peaks, namely, [M] and [M-35], two classification criterions were proposed. According to criterion I, class 1 comprises [M] signals with the intensity higher than 800 NIST units, while class 2 consists of signals with the intensity lower or equal than 800. According to criterion II, class 1 consists of [M-35] signals with the intensity higher than 100, while signals with the intensity lower or equal than 100 belong to class 2. As a result of ANNs learning stage, five models for both classification criterions were generated. The external model validation showed that all ANNs are characterized by high predicting power; however, criterion I-based ANNs are much more accurate and therefore are more suitable for analytical purposes. In order to obtain another confirmation, selected ANNs were tested against additional dataset comprising popular sunscreen agents disinfection by-products reported in previous works.
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