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Estimation of Phosphorus Reduction from Wastewater by Artificial Neural Network, Random Forest and M5P Model Tree Approaches Полный текст
2020
Kumar, S. | Deswal, S.
This study aims to examine the ability of free floating aquatic plants to remove phosphorus and to predict the reduction of phosphorus from rice mill wastewater using soft computing techniques. A mesocosm study was conducted at the mill premises under normal conditions, and reliable results were obtained. Four aquatic plants, namely water hyacinth, water lettuce, salvinia, and duckweed were used for this study. The growth of all the plants was inhibited in rice mill wastewater due to low pH, high chemical oxygen demand, high conductivity, and high phosphorus concentration. Subsequently, a 1:1 ratio of mill water to tap water was used. A control was maintained to assess the aquatic plant technology. In this study, the aquatic plants reduced the total phosphorus content up to 80 % within 15 days. A comparison between three modeling techniques e.g. Artificial neural network (ANN), Random forest (RF) and M5P has been done considering the reduction rate of total phosphorus as predicted variable. In this paper, the data set has been divided in two parts, 70 % is used to train the model and residual 30 % is used for testing of the model. Artificial neural network shows promising results as compared to random forest and M5P tree modelling. The root mean square error (RMSE) for all the three models is observed as 0.0162, 0.0204 and 0.0492 for ANN, RF and M5P tree, respectively.
Показать больше [+] Меньше [-]Phytotoxicity of Lead and Chromium on Germination, Seedling Establishment and Metal Uptake by Kenaf and Mesta Полный текст
2020
Sultana, R. | Islam, S. M. N. | Zaman, M. W. | Uddin, N.
Heavy metal contaminated soil raises major global environmental and agricultural concern. Recently soil pollution through lead (Pb) and chromium (Cr) becoming serious problem and remediation or utilization of those contaminated soil with potential crops is of the outmost importance. The objectives of present study were to examine the effects of Pb and Cr on three different kenaf and mesta varieties for seed germination, seedling establishment and amount of Pb and Cr uptake by tested varieties in laboratory condition. Three varieties were used for the study namely, HC-95 (kenaf), CPL-72126 (mesta) and Samu-93 (mesta) and the treatments were combination of Pb and Cr chemical at (0,0), (60,60), (80,80), (100,100) and (120,120) mg/L. Increased level of lead and chromium gradually reduced the germination percentage and primary growth parameters compared to control. The shoot and root lengths were affected only little, whereas, the biomass showed a considerable reduction with the increase of Pb and Cr toxicity. Stress tolerance indices showed a gradual and negative response by the plant with the increase of metal concentrations. However, in all the levels of Pb and Cr treatment, the seedlings were capable to tolerate the toxicity and seedlings were established. Bioaccumulation of Cr was higher than that of Pb in all varieties and in all treatments. The interaction of Pb and Cr reduced the toxic effect of both metals to the plants. The findings are helpful for selecting fiber crop varieties for cultivation in contaminated soils or phytoremediation of Pb and Cr from the contaminated soils.
Показать больше [+] Меньше [-]Fixed Bed Column Modeling of Cd(II) Adsorption on Bone Char Using Backward Bayesian Multiple Linear Regression Полный текст
2020
Amiri, M. J. | Mahmoudi, M. R. | Khozaei, M.
In this work, the backward Bayesian multiple linear regression (BBMLR) as a new approach is presented to predict the adsorption efficiency (AE) of Cd(II) ions by ostrich bone char (OBC) in the fixed bed adsorption with four operational variables consisting of pH (2-9), inlet Cd(II) concentration (Co= 25-100 mg/L), bed depth (h= 3-9 cm) and feed flow rate (Q= 0.5-30 mL/min). The performance of the BBMLR was evaluated using the coefficient of determination (R2), normalized root means square error (NRMSE) and mean residual error (MRE). The AE of Cd(II) ions by OBC increased from 42.3% to 99.9% when pH was increased from 2 to 9 with h of 6 cm and Q of 1.5 mL min-1. It was found that the AE dramatically increased from 70.5% to 99.9% with decreasing Q from 30 to 0.5 mL min-1 at pH of 7 and h of 6 cm. At pH= 7 and Q= 1.5 mL min-1, the AE increased from 71.9% to 100% when h increased from 3 to 9 cm. The BBMLR model presented excellent performance (NRMSE=6.69%) for predicting Cd(II) removal in a continuous adsorption system, although it gave a slight underestimation (approximately 3.52%). The BBMLR is more sensitive to the pH, followed by h and Q, while the Co has no significant effect on it. This research displays that OBC has great potential as an eco-friendly low-cost adsorbent in removing Cd(II) ions from the contaminated waters.
Показать больше [+] Меньше [-]Dust Crises and its Regional Geopolitical and Security Impact in West Asia Полный текст
2020
Abdi, A. | Yazdanpanah, Q. | Javadi, Z.
Western Asia has recently become an arena for significant upheavals of various kinds, be it political, safety-related, geopolitical, social, etc. These have in turn focalized the salience of the region as well as its ensuing situation and challenges on a global perspective. Such a naturally-born phenomenon is characterized, amidst other factors, by its transregional quality, granting it some sort of geopolitical peculiarity. The occurrence of haze would implicate a merged endeavor on part of the countries, engaged in this cross-regional abnormality. This joint endeavor is, however, hindered and at times exacerbated due to certain political inconsistencies among the countries, undoubtedly rising from differences in ideology, religion, politics, and social standards. In this light, the present study seeks to inquire the impacts of haze, as a geopolitical phenomenon, on involved countries. It also tries to find out whether subsequent implications of this predicament could in effect be employed to establish new relations among rather-standoffish nations or if they are merely components of a cold relation among countries and could intensify each nation’s problems, reducing the overall quality of life further. The findings indicate that despite the existent domestic and transregional problems, public opinion tends to establish joint cooperation among the engaged countries. This is not in the least a result of fear of a low life quality among the inhabitants of the said nations.
Показать больше [+] Меньше [-]Decolorization of Reactive Black-5 High Concentration by Vermicompost Microflora and Detoxification of By-Products by UV-C/H2O2 Post-Treatment Полный текст
2020
Emadi, Z. | Sadeghi, M. | Mohammadi-moghadam, F. | Sadeghi, R. | Forouzandeh, S. | Sadeghi, R.
The presence of synthetic dyes in textile wastewater is a problematic issue for environmentalist. Nowadays, dye removal is practiced via different methods. Among all these methods, biodecolorization is an ideal technique. The present research apples vermicompost microflora to remove reactive black- C, pH = 7, and under anaerobic condition. At 36h, removal efficiencies of 94.79%, 94.06%, and 93.6% are obtained for concentrations of 800, 850, and 950 mg/ L, respectively. It has also been observed that when the initial concentration rises to 1400 mg/ L, the efficiency drops to 51.57% at 36h. Also, methyl red, methyl orange, eriochrome black-t, and acid blue-113 could be decolorized by the isolated bacterial strain with an efficiency of 94.29%, 92.10%, 90.83%, and 88.95%, respectively. Phytotoxicity Test shows that the parent form of reactive black-5 has not been toxic for the seeds (100% germination for Triticum aestivum and 90% for Maize). When reactive black-5 is treated with isolated bacterial strain under anaerobic condition, none of the seeds remain germinated which might be due to the possible formation of toxic aromatic amines intermediates. Therefore, ultraviolet C + 100 mM H2O2 has been used as the post-treatment process for detoxifying of by-products. After the integrated treatment of synthetic wastewater, containing RB-5, complete germination (100%) of Triticum aestivum and Maize is observed. In the post-treatment process, due to the generation and activation of hydroxyl radicals, the toxic aromatic amines compounds convert to the less toxic compounds.
Показать больше [+] Меньше [-]Assessment of Disposal Scenarios for Solid Waste Management Using Fuzzy Rapid Impact Assessment Matrix; a Case Study of Khorramabad Industrial Estate Полный текст
2020
Ghobadi, M. | Ahmadipari, M. | Pazoki, M.
The present paper tries to assess different scenarios for solid waste management in Khorramabad industrial park. It uses a new hybrid method of fuzzy Rapid Impact Assessment Matrix, and proposes the Fuzzy theory, the ranking method of which is innovated so that the accuracy and flexibility of the RIAM method could be improved. Four scenarios are studied, namely open dumping, sanitary landfill, gasification, and incineration. They are then evaluated in terms of their physical/chemical, biological/ecological, social/cultural, and economic/operational effects. Afterwards, two scenarios have been selected with the aim of energy production. The evaluation of these aspects for each scenario is in accordance to the expert's judgments and field study, with the results showing that sanitary landfill has had the least undesirable effects. Hence, this approach is selected as the best scenario for waste management in the studied area. According to the obtained results, it is suggested to consider sanitary landfills as the main part of the waste management hierarchy program of the studied area. Also, it is highly recommended to use the Fuzzy RIAM technique in similar studies and to compare the results with the new ones in order to examine the accuracy of the new improved method.
Показать больше [+] Меньше [-]Effect of Composting Process on Some Chemical-Biological Properties and Heavy Metals Behavior of Municipal Sewage Sludge as Affected by Various Bulking Agents Полный текст
2020
Saffari, M. | Saffari, V. R. | Khabazzadeh, H. | Naghavi, H.
The present study tries to investigate the effect of composting process on some properties and heavy metals status of two municipal sewage sludge (MSS) as affected by three different organic bulking agents (BAs) at three levels (10%, 25%, and 45% V/V). According to the results, the composting process could reduce the fecal coliform to class A, a reduction more obvious in treatments with BAs than produced composts without them. Changes in the chemical properties of the composts vary according to the type of MSS and Bas. Based on the compost quality standard, most of the produced samples are classified in compost-class II. Examination of the total form of three heavy metals (HMs: Zn, Ni, Fe) of both MSS shows that composting process without BAs increases the HMs total concentration, but using of BAs have not been clear trends. In the contrary, BAs application reduced the available form of Fe and Ni, but increased the Zn available form. Examination of chemical forms of each studied HMs also shows that the composting process reduces the Ni and Fe mobility factor, but increases that of Zn. Generally, while, prepared composts can classify into the compost-class II, based on their properties, the high concentration of total Zn above the standard limit makes it extremely restrictive to be used as class II compost. However, according to EPA regulations, the composts with this concentration of Zn can be used as a relatively safe organic material on agricultural land.
Показать больше [+] Меньше [-]Bio-Accumulation of Lead and Cadmium by Radish (Raphanus sativus) and Cress (Lepidium sativum) under Hydroponic Growing Medium Полный текст
2020
Hedayatzadeh, F. | Banaee, M. | Shayesteh, K.
In order to investigate the accumulation and bio-absorption of lead and cadmium in radish and cress, the present study has been conducted in a completely randomized design in three replicates in a hydroponic growing medium. The first factor includes the plant type at two levels (radish and cress), and the second factor is consisted of lead (Pb) (first experiment) at two levels (50 and 100 mg/L), cadmium (Cd) (second experiment) at one level (10 mg/L), and a combination of lead and cadmium (third experiment) again at two levels. After 23 days, roots and aerial parts of both plants have been dried for 48 hours at 70°C in an oven. Then, half gram (0.5 g) of the dried templates has been used to measure the accumulation of Pb and Cd by means of an atomic absorption spectrometer. The highest amount of Pb in radish and crest roots belong to 100 mg/L concentration and the combined Cd (10) + Pb (100) mg/L treatment, respectively, and the highest amount of Cd occurs in Cd (10) + Pb (50) for radish roots and in Cd (10) + Pb (100) combination for cress. Moreover, the Translocation Factor (TF), with a value below 1 and higher bio-concentration factor (BCF) in roots, compared to the aerial part of both radish and cress, seem to be due to the low capability of these plants to transfer Pb and Cd from roots to aerial part. There is a high potentiality for lead accumulation in the roots that prevent its transfer to the aerial part.
Показать больше [+] Меньше [-]Effect of Barley and Oat Plants on Phytoremediation of Petroleum Polluted Soils Полный текст
2020
Barati, M. | Safarzadeh, S. | Mowla, D. | Bakhtiari, F.
Total Petroleum Hydrocarbons (TPHs) are one of the most dangerousorganic contaminants in the environment. Therefore, the remediation of the oilcontaminatedsoil is necessary. The growth of barley and oat plant was studied in thecontaminated soils (4, 6, 8% TPHs) during 5 months. Plant height, wet and dry weight ofshoots and roots of both plants were measured. Results showed that oat and barley height,wet and dry weight of shoots and roots decreased with increasing contamination levels.Regardless of the plants species, the highest rate of TPH reduction was observed in soilwith 4% contamination and decreased with increasing the contamination level. The TPHsconcentration in the rhizosphere of barley and oat decreased by 29.66 and 24.04% at the6% TPHs level and by 21.24 and 17.48% at the 8% TPHs level, respectively. Cultivationof barley and oat plants significantly accelerated the biodegradation of hydrocarbons andreduced TPHs content in soil as compared to unplanted soil.
Показать больше [+] Меньше [-]Emissions and Fuel Life Cycle Assessment of Non-passenger Diesel Vehicles in Qatar Полный текст
2020
Al-Thani, H. | Al-Ghamdi, S. | Koc, M. | Isaifan, R. j.
The life cycle of diesel fuel in non-passenger vehicles was assessed for all registered vehicles in Qatar as of November 2017. The Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model was used as a source of normalized data to evaluate diesel fuel emissions for all non-passenger vehicle categories. This work aims at estimating the emissions from all non-passenger diesel vehicles in Qatar and evaluating the impact of the fuel life cycle assessment. The emissions of CO2, NOx, CO, SO2, VOC, black carbon (BC), organic carbon, fine particulates PM2.5, and coarse particulates PM10 were evaluated. SO2 emissions were found to be dominant during the well to pump (WTP) stage of the life cycle assessment (LCA) process, while the pump to wheel (PTW) stage was found to be dominated by CO, VOC, PM10, PM2.5, and BC emissions. NOx and organic carbon emissions were virtually the same during both stages. Total greenhouse gas emissions amounted to 5367 kt of CO2 equivalent (CO2-eq) in 2017 as compared with that in 2014 (5277 kt), the only reported value in Qatar for transportation emissions. In addition, several mitigation strategies are proposed to ensure sustainability in the transport sector and to minimize the negative impact of diesel fuel emissions in the country.
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