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Effect of Composting Process on Some Chemical-Biological Properties and Heavy Metals Behavior of Municipal Sewage Sludge as Affected by Various Bulking Agents
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.
Mostrar más [+] Menos [-]Performance and emission characteristics of the diesel engine running on neem (Azadirachta indica) biodiesel with effect of exhaust gas recirculation at optimum injection strategies
2020
Singh, Y. | Singla, A. | Sharma, A. | Singh, N. K.
Environmental pollution and strict emission norms are promoting researchers to explore the methods for reducing pollution and provide optimum solution. By considering these situation as the baseline, study was conducted to analyse the effect of exhaust gas recirculation (EGR) on performance and emission of the DI diesel engine. The effects of Injection Timings (IT), split injection and Exhaust Gas Recirculation on performance, emission characteristics of diesel engine fuelled neem biodiesel blends are investigated. Initially experiments are conducted with diesel, NB5, NB10 with original injection timing of 23° bTDC with direct injection and are considered as base reading. The fuel injection is optimized (at 19° bTDC and 16% split injection) and the effect of EGR rate at this optimized condition is analysed. Significant reduction of about 65.3%, 67% and 57% in the amount of NOx was obtained at full load as compared to base readings. Smoke emissions reduced by 2.8-3.4% and CO emissions reduced by around 52% for diesel and biodiesel blends at full load.
Mostrar más [+] Menos [-]Algal Indices as a Biomonitoring Tool to Assess Eutrophication in the Urban Ponds: a Case Study
2020
Vishal, R. | Meeta, B.
Eutrophication of the urban water bodies is one the biggest challenge causing severe ecological and economic loss. Urban ponds are more prone to eutrophication due to their small size and polluted catchment areas. Biomonitoring using phytoplankton provides cost-effective estimation of the level of eutrophication. Ten urban ponds in different areas of the Mumbai city were chosen to investigate the phytoplankton community structure, and level of eutrophication. We assessed the 3 algal indices viz. Shannon-Wiener indices, Palmer and Nygard's (Myxophycean and diatom) indices. Linear relationship of these indices was tested against Carlson trophic state indices in order to assess the effectiveness of these indices to measure the degree of eutrophication in urban lakes. All ten lakes were found to be eutrophic, of which two were very low eutrophic (TSI – 53.74-53.95), four were low-mid eutrophic (TSI – 55.18 – 57.5), and four lakes were mid eutrophic (TSI 61.4 – 62.2). Shannon-Wiener indices (r= -0.73) and Myxophycean indices (r= 0.77) showed strong correlation with TSI whereas Diatom indices (r= -0.12) and Palmer’s Algal Pollution Indices (r= - 0.47) showed weak correlation with TSI. Thus study found that Shannon-Wiener indices and Myxophycean indices are reliable and cost effective means to assess the eutrophication of urban ponds in Mumbai.
Mostrar más [+] Menos [-]Phytoremediation of soil Contaminated by Heavy Metals within a Technical Landfill Center Vicinity: Algerian Case Study
2020
Boukaka, Kh. | Mayache, B.
The contamination of environment with heavy metals has become a serious problem which can affect the human health. Three heavy metals (Zn, Cd and Pb) were determined in soil and plants for below and aboveground parts along landfill Demina center, located in the wilaya of Jijel, Algeria to evaluate their behavior and uptake by Ditrichia viscosa, Juncus effusus and Solanum nigrum. In our research we tried to study the capacity of these spontaneous plants to accumulate and to translocate heavy metals from soil to their tissues during three years. The heavy metals examined in the soils of the study area showed variations in concentrations, the study area may be practically unpolluted with Zn and Pb (CF; 0.45 and 0.98 successively) and very contaminated with Cd (CF; 8.53). According to the results obtained, the soil is uncontaminated with lead (Igeo=-0.60) and zinc (Igeo= -1.42) but it is heavily contaminated with cadmium (Igeo=2.5) along the study area. Overall the BCFS (bioconcentration factors) are superior to 1, for the all heavy metals and species. However, BCFs follow the following order; BCFZn>BCFPb>BCFCd for Ditrichia viscosa, the following order BCFPb>BCFZn>BCFCd for Juncus effuses and follow the following order; BCFZn>BCFCd>BCFPb for Solanum nigrum. The TFs (translocation factor) of the present study showed that Solanum nigrum can translocate the three of the metals into their aboveground parts.
Mostrar más [+] Menos [-]Synthesis and characterization of activated carbon from biowaste-walnut shell and application to removal of uranium from waste
2020
Yaman, M. | Demirel, M. H.
The aim of this study is to synthesize and characterize an economical and environmentally-friendly adsorbent with high adsorption capacity. For this purpose, the walnut shells (Juglans regia L.) were chemically modified using sulfuric and citric acids, separately. After pyrolysis and synthesis of activated carbon (AC), the optimization of conditions at the preconcentration/removal step was performed using parameters such as pH and contact time for uranium in the model solutions. The measurements were carried out by inductively coupled plasma-mass spectrometry (ICP-MS). From the shapes of the BET isotherms, it may be stated that activated carbon exhibit type I. It was found that the surface area and total pore volume of the activated carbon were 696.6 m2/g and 0.35 mL/g, respectively. The adsorption capacity was found to be 220 mg/g. It was found that the optimum pH is 6.0 for preconcentration/removal using AC obtained by sulfuric acid as chemically-modifier. The optimized method was applied to determination of U at ng/mL levels in the model solutions.
Mostrar más [+] Menos [-]Carbon Monoxide Prediction in the Atmosphere of Tehran Using Developed Support Vector Machine
2020
Akbarzadeh, A. | Vesali Naseh, M. R. | NodeFarahani, M.
Air quality prediction is highly important in view of the health impacts caused by exposure to air pollutants in urban air. This work has presented a model based on support vector machine (SVM) technique to predict daily average carbon monoxide (CO) concentrations in the atmosphere of Tehran. Two types of SVM regression models, i.e. -SVM and -SVM techniques, were used to predict average daily CO concentration as a function of 12 input variables. Then, forward selection (FS) technique was applied to reduce the number of input variables. After converting 12 input variables to 7 using the FS, they were fed to SVM models (FS-(-SVM) and FS-(-SVM)). Finally, a comparison among SVM models operation and previously developed techniques, i.e. classical regression model and artificial intelligent methods such as ANN and adaptive neuro-fuzzy inference system (ANFIS) was carried out. Determination of coefficient (R2) and mean absolute error (MAE) for -SVM (-SVM) were 0.87 (0.40) and 0.87 (0.41), respectively, while they were 0.90 (0.39) and 0.91 (0.35) for ANN and ANFIS, respectively. Results of developed SVM models indicated that both FS-(-SVM) and FS-(-SVM) regression techniques were superior. Furthermore, it was founded that the performance of FS-(-SVM) and FS-(-SVM) models were generally a bit better than the best FS-ANFIS and FS-ANN solutions for short term forecasting of CO concentrations.
Mostrar más [+] Menos [-]Emerging Pollutants in Aquatic Environment: Source, Effect, and Challenges in Biomonitoring and Bioremediation- A Review
2020
Patel, N. | Khan, MD. Z. A. | Shahane, S. | Rai, D. | Chauhan, D. | Kant, C. | Chaudhary, V. K.
Emerging contaminants are distributed in to the environment from various anthropogenic activities. These Emerging contaminants (ECs) are mainly composed of products, such as pharmaceuticals, personal care products (PCPs), surfactants, plasticizers, pesticides etc. The present conventional system of waste treatment are not designed to treat these contaminants. Complex structure of these pollutants and their existence at low concentration makes them untraceable and hence found to be difficult in removal of these by present waste treatment. These chemicals are considered as threat to human health and environment. Therefore, disposal and treatment of these chemicals of emerging concern have been a key concern in the field of water treatment and its reuse. Biosensors can be used for biomonitoring of these contaminants with of biological system. Bioremediation plays an important role in the treatment of these pollutants of emerging concern. This review discusses about the sources, effects, and challenges in biomonitoring and bioremediation related to these emerging contaminants.
Mostrar más [+] Menos [-]Health Impacts Assessment due to PM2.5, PM10 and NO2 Exposure in National Capital Territory (NCT) Delhi
2020
Afghan, F. R. | Patidar, S. K.
The human health impacts caused due to exposure to criteria outdoor air pollutants PM2.5, PM10 and NO2 were assessed in present study. The human health effects associated with exposure to atmospheric air pollution in NCT Delhi were estimated utilizing the AirQ+ v1.3 software tool integrated with Ri-MAP during the study period 2013-2018 considering 80% of the whole population subjected to air pollution exposure. Taking into account the World Health Organization (WHO) (2016) guidelines, the inter-annual average concentrations of PM2.5, PM10, and NO2, concentration response relationships and population attributable fraction (AF) or impact fraction (IF) concepts were adopted. The excess number of cases (ENCs) of Mortality (all) natural cases 30+ years, acute lower respiratory infection (ALRI), lung cancer (LC), ischaemic heart disease (IHD), stroke, incidence of chronic bronchitis in children, postneonatal infant mortality, chronic obstructive pulmonary disease (COPD), prevalence of bronchitis in children, incidence of asthma symptoms in asthmatic children in the year 2013 were 48332, 2729, 5645, 26853, 22737, 120754, 34510, 5125, 9813, 3054, 17203 and 682, respectively. Within half of a decade i.e. in year 2018, the ENCs of Mortality (all) natural cases 30+ years, ALRI, COPD, LC, IHD, stroke, incidence of chronic bronchitis in children, postneonatal infant mortality, prevalence of bronchitis in children, incidence of asthma symptoms in asthmatic children increased significantly and were 72254, 3471, 6547, 7568, 32358, 28233, 150110, 50810, 9019, 862, 29570 and 1189, respectively.
Mostrar más [+] Menos [-]Development of the Ethyl Ester from Jatropa Oil through Response Surface Methodology Approach
2020
Gautam, R. | Ansari, N. | Sharma, A. | Singh, Y.
With an increase in the global pollution, there is requirement for an alternative to the fossil fuels. Non-edible vegetable oils are highly promising for producing liquid fuels like diesel. Jatropha is a potential feedstock for biodiesel, currently utilized in India and many parts of the world. The optimization of reaction conditions such as temperature, time, catalyst and molar ratio for biodiesel production is important in reactor design. However, oils have characteristics reaction properties for optimum yield. Therefore, there is the need to identify such parameters in Jatropha oil ethyl esters production. Preparation of biodiesel from Jatropha oil ethyl esters using conventional homogeneous process. Optimization of Jatropha ethyl esters using Response surface methodology is done and data so obtained are fed to the design experiment software for analysis. The Jatropha ethyl esters yield was 92.62%. Maximum production of Jatropha oil ethyl ester was achieved with the process parameters viz molar ratio 8.5, reaction time 89.67min, reaction temperature 70.1°C and catalyst.0.62wt%.
Mostrar más [+] Menos [-]Nitrate Bioremoval by Phytotechnology using Utricularia aurea Collected from Eutrophic Lake of Theerthamkara, Kerala, India
2020
Usharani, K. | Keerthi, K.V.
The aim of this study was to compare the selected aquatic plants ability to remove nitrate from wastewater. Excess of these nutrients in water can directly affect human health (methemoglobinaemia) or indirectly through the products of secondary pollution include eutrophication. Negative impact of nutrients excess in surface water often causes the destruction of water ecosystems, and therefore, common substances of these elements must be monitored and managed. Spectrophotometric technique was commonly used for quick and simple analyses of nutrients in waste water. There are calibration curves for each nutrient and for the determination of their concentration. Phytotechnology is one of the biological wastewater treatment methods or processes to eliminate nitrate contaminant from aquatic system. So as to avoid the eutrophic formation of fresh water and to determine the efficiency of nitrate utilization by specific aquatic plants which include Utricularia aurea and Salvinia molesta were collected from a eutrophic lake at Theerthamkara, Kerala. The samples were allowed to grow in nitrate solution for about one month at different concentrations. The optical density (OD) of nitrate solution at 410 nm was measured on alternative days of the experiment by using UV spectrophotometer. After 33 days of treatment periods, the maximum amount of nitrate removed in terms of percentage was found to be 95% by Utricularia aurea and 92% by Salvinia molesta at 100 ppm nitrate concentration. The results revealed that the aquatic plant (carnivorous) based system of phytotechnology was productively removed the nitrate load from the synthetic wastewater containing nitrate.
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