Refine search
Results 21-30 of 8,088
Particulate Matter and Adverse Respiratory Health Outcome: Exposure of Street Vendors in Kolkata city in India Full text
2021
Ghosh, Nabanita | Das, Biplob | Das, Nandini | Chatterjee, Souran | Debsarkar, Anupam | Dutta, Amit | Chakrabarty, Shibnath | Roy, Joyashree
Exposure to airborne particulates is a major occupational hazard especially for outdoor workers who spending time outdoors at ground level getting exposed to traffic fumes and roadside dust. Aim of this study was to assess respiratory health symptoms and determine the change of lung functions of the roadside vendors and its association with traffic-related exposures and their working experience. A cross-sectional study was conducted in key market places of Kolkata – Gariahat (GH), Esplanade-Park Street (EP), Shyambazar-Hatibagan (SH) and Behala (BE). Particulate (PM10 and PM2.5) levels and meteorological parameters (wind speed, temperature and relative humidity) were monitored in the morning, afternoon and night over the period of October 2019 to February 2020. Lung function status (FEV1, FVC, FEV1/FVC ratio and PEF) was measured for 111 purposively selected participants. PM concentration was observed higher in the morning and night peak hours for all sites. At SH area the average occupational exposure level for PM10 and PM2.5 were observed as 1502.22 μg/m3h and 684.01 μg/m3h. Percentage predicted FEV1 (%FEV1) of street vendors was found decreasing with their work experience and the worst-case scenario was observed in the EP area, with the corresponding value being 70.75%, 49.15% and 47.3% for less than 10 years, 10 to 20 years and more than 20 years participation respectively. The higher particulate burden was observed to have declining lung function status of the street vendors. A strong policy framework should be adopted to improve outdoor working environment for outdoor workers.
Show more [+] Less [-]Treatment Oilfield Produced Water using Coagulation/Flocculation Process (case study: Alahdab Oilfield) Full text
2021
Jabbar, Hussein Ali | Alatabe, Mohammed jaafar Ali
Produced water is a large amount of water wasted throughout the crude oil extraction process, it's a mixture of the well's deposition water and the water of oil wells extraction water. Produced water contains oil, suspended solids and dissolves solid. This study tested produced water collected from Alahdab oilfield/middle oil company for oil content and suspended solid contamination using chemical precipitation and coagulation-flocculation for reinjection and environmental considerations. Coagulation/flocculation is a common method used as primary purification to oily wastewater treatment due to its usability, performance, and low cost. Coagulant experimental was completed by A jar test device, additives of ferric sulfate and aluminium sulfate were in a range about (10 ـ 40) ppm, as well as polyelectrolyte- (polyacrylamide) as an additional flocculent in the range (1.5-3) ppm. The results show that ferric sulfate was more efficient at removing turbidity than aluminium sulfate under the same conditions, with the best removal of turbidity at dose concentration 30 ppm of Ferric sulfate and a flocculent dose concentration of 2.5 ppm of polyacrylamide, also with oil content decreasing from 396.71 ppm to 53.56 ppm.
Show more [+] Less [-]Exploring the use of Macrophytes as Biological Indicators for Organic Pollution of Chanchaga River in North Central Nigeria Full text
2021
Ali, Andrew | Obi-Iyeke, Grace | Keke, Unique | Arimoro, Francis
Macrophytes are creatures with low versatility and cannot stay away from any mix of streamflow, nutrient accessibility, and other physical and chemical attributes that impact their survival in the aquatic system. Sampling for macrophytes in Chanchaga River was conducted monthly for a 6-month period (May - October 2019). Sampling stations were selected at approximately equal distance along the streamline, the aquatic vegetation were surveyed, and some environmental variables were analysed using standard methods. Results obtained indicated that temperature ranged from 24.6-28.4°C; pH 6.4 -9.7; Electrical conductivity 28.0-79.0μS cm-1; Total dissolved solids 16-75 mg L-1; Dissolved oxygen(DO) 1.3-5.2 mg L-1; Nitrate 0.217-0.654 mg L-1; Phosphate 0.084-0.211 mg L-1; Biological oxygen demand (BOD) 0.89-5.4 mg L-1 and total alkalinity 8.00-11.00 mgL-1 for the study period. A total of eleven (11) macrophyte species belonging to ten genera and eight families were identified during the entire study. Variations in terms of families showed that Araliaceae was the most abundant followed by Poaceae, while Cyperaceae had more species throughout the study period. The high frequency of Araliaceae, Cyperaceae, and Poaceae families suggests that the environmental characteristics favour these species. We propose the use of Cyperus digitatus, Cyperus papyrus and Mimosa spp. as macrophytes indicators of organic pollution in Chanchaga River.
Show more [+] Less [-]Analysis of Water Quality Trends Using the Mann-Kendall Test and Sen’s Estimator of Slope in a Tropical River Basin Full text
2021
Hashim, Mohmadisa | Nayan, Nasir | Setyowati, Dewi Liesnoor | Said, Zahid Mat | Mahat, Hanifah | Saleh, Yazid
Trends in water quality, either increasing or decreasing over the long term, are becoming an essential guide to understanding water quality. This study aims to analyse the trends in water quality in the upstream part of the Bernam River Basin, Malaysia from 1998 to 2018. This study involved the collection of data on water quality from the Department of Environment, Malaysia. Six main parameters of the water quality index (WQI) were chosen, including the dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N), total suspended solids (TSS) and pH. The analysis methods applied are the Mann-Kendall test and Sen’s estimator of slope. The results of the WQI value trend analysis revealed that most stations have decreasing trends. A trend analysis of the parameters found that most stations had increasing trends for the DO, BOD, NH3-N and pH parameters, while decreasing trends for the COD and TSS parameters were observed. An increasing trend indicated that the water quality parameters were getting better, and a decreasing trend indicated the opposite. This study will benefit the parties responsible for planning and monitoring developments to reduce water pollution around the upstream Bernam River Basin. In the upstream of Bernam River Basin, land use changes have occurred rapidly, especially forest areas have been explored for human settlements, agricultural and industrial activities. Thus, the sustainability of the river basin can be maintained and valued by the various parties in the future. The river basin is also important as a domestic water supply for the residents of Selangor and Perak.
Show more [+] Less [-]Production of Eco-Friendly Geopolymer Concrete by using Waste Wood Ash for a Sustainable Environment Full text
2021
Arunkumar, Kadarkarai | Muthukannan, Muthiah | Suresh Kumar, Arunachalam | Chithambar Ganesh, Arunasankar | Kanniga Devi, Rangaswamy
Climate change could be exacerbated by waste disposal problems, which destroy the ecosystem. Utilizing waste byproducts in creating eco-friendlier geopolymer concrete was hypothesised to be suitable and sustainable to overcome the negative impacts of wastes. The researchers had missed out on developing an alternate binder due to increasing demand for fly ash, high alkaline activators, and higher curing temperatures. This research used waste wood ash that is readily accessible in local restaurants and has an inherent potassium constituent. It has decided to replace the fly ash with waste wood ash obtained through nearby restaurants at intervals of 10 percent. The fresh and mechanical features have been discovered over long curing periods to assess the impact of waste wood ash. SEM and XRD have been used for characterising the microstructure of selected geopolymer mixes. In terms of setting properties and all mechanical parameters, replacing 30 percent waste wood ash produced enhanced results. The optimised mix could be used in geopolymer to replace fly ash and reduce the cost of alkaline activators while also reducing ecosystem damage.
Show more [+] Less [-]Textile Wastewater Treatment by Combination of Chemical and Phytoremediation Processes Full text
2021
Tasneem, A. | Sarker, P. | Akter, S. | Mouna, S.S.P. | Rahaman, M. S. | Mohinuzzaman, M. | Uddin, M.K. | Kabir, M. M.
In the present investigation, coagulation-flocculation and fenton process in conjunction with phytoremediation by water hyacinth (Eicchornia crassipes) were applied to treat the most frequently occurred contaminants in textile wastewater. The mean values of EC, TDS, turbidity, pH, DO, BOD, COD and TOC in the raw effluents were 2300 μSCm-1, 1260 mgL-1, 48.28 FTU, 10.5, 1.2 mgL-1, 265 mgL-1, 522 mgL-1 and 12.8 mgL-1, respectively whereas the average concentration of Cr, Pb, Mg, Cu, Ni and Zn was 0.86, 1.21, 10.97, 0.47, 2.85 and 0.52 mg/L, correspondingly which evidently indicated that the effluents were highly contaminated compared to Bangladeshi standard. The results demonstrated that the values of EC, TDS, turbidity, pH, BOD, COD and TOC reduced significantly compared to raw effluents by both coagulation-flocculation and fenton processes and meet the standards set by BDS-ECR except BOD and DO. After being treated the COD value reduced to 70 mg/L (86.56%) and 188 mg/L (63.985%) from its initial concentration by coagulation-flocculation and fenton process, respectively on the other hand TOC removal efficiency by coagulation- flocculation process was 97.8125%, significantly greater than fenton methods where removal efficiency was 63.9%. However, the BOD removal efficiency by both treatment processes was ~50% which was not satisfactory compared to local standard. Interestingly, the concentration of DO increased substantially by both coagulation-flocculation (1.2 to 4.4 mg/L) and fenton process (1.2 to 3.85 mg/L). In case of trace elements removal, the combination of coagulation-flocculation-water hyacinth and fenton-water hyacinth show promising results where the removal efficiency of coagulation-flocculation-water hyacinth and fenton-water hyacinth was 24%-76% and 17%-76.36%, respectively. Therefore, it can be concluded that coagulation-flocculation-water hyacinth combination is better than fenton-water hyacinth combination in terms of trace metals removal. Textile effluents treatment and management is considered as one of the most significant issues in Bangladesh herein based on the this study, combination of chemical and phytoremediation technologies could be a promising sustainable low cost alternative for Bangladesh’s textile industrial sector.
Show more [+] Less [-]Evaluation and forecasting of PM10 air pollution in Chennai district using Wavelets, ARIMA, and Neural Networks algorithms Full text
2021
Angelena, J. P. | Stanley Raj, A. | Viswanath, J. | Muthuraj, D.
The advent of advanced features of soft computing can be used to solve complex problems which are more non-linear and messy. Many of the applications have been analysed and validated by the researchers through soft computing approach in the past.Neural Networks (NN) with appropriate selection of training parameters is implemented apart from conventional mathematical model. In this paper, analysis is made on the estimation of PM10 air quality in selected regions of Chennai district by wavelet approach with energy spectrograms. After analysing the results, NN of multilayer feed forward back propagation algorithm forecasts the air quality of selected regions. Discrepancies in selecting the training parameters of NN’s have been overcome by trial and error basis. This work will be helpful in proving the powerful tool of NN to forecast short term nonlinear parameters and the predicted results will give us the clear design of existing problem and thecontrol measures need to be implemented.
Show more [+] Less [-]Identifying the effects of climate changes on sedimentary environments and determining the sedimentation rate of south wetlands of Lake Urmia during Late Pleistocene and Holocene Full text
2021
Mirzapour, B. | Lak, R. | Aleali, M. | Djamali, M. | Shahbazi, R.
This study investigated the evolutionary history of the Late glacial in number of wetlands in south part of Lake Urmia. Twenty-six cores with a maximum depth of 12 m, average 8 m and total depth of about 190 m were collected from sediments under the southern and southwestern wetlands using a handi auger. Sedimentary facies were identified and separated based on sediments texture and structure, composition of evaporite minerals and organic materials, also color and other macroscopic elements. The results indicated the presence of eight distinct sedimentary facies belonging to the lacustrine, wetland and fluvial (river) sedimentary environments. In the last 20 cal ka BP, the two dominant dry periods, about 4 cal ka BP and 13 cal ka BP, have been associated with the transgression of dry (alluvial) facies towards the lake and the regression of Lake facies. The dry period 4 cal ka BP affected the southern part of Lake Urmia and marginal wetlands, while the dry period 13000 years ago was more intense and longer and lasted at least 3 cal ka BP.In the last 2cal ka BP, the two dominant dry periods, about 4 cal ka BP and 13 cal ka BP, have been associated with the transgression of dry (alluvial) facies towards the lake and the regression of Lake facies. The dry period 4 cal ka BP affected the southern part of Lake Urmia and marginal wetlands, while the dry period 13000 years ago was more intense and longer and lasted at least 3 cal ka BP.
Show more [+] Less [-]Determinants of Environmental Degradation in Thailand: Empirical Evidence from ARDL and Wavelet Coherence Approaches Full text
2021
Adebayo, T. S. | Akinsola, G. D. | Odugbesan, J. A. | Olanrewaju, V. O.
This paper explores long-run and causal effects of financial development, real growth, urbanization, gross capital formation and energy consumption on CO2 emissions in Thailand by utilizing recent econometric techniques. The study employs ARDL technique to examine the long and short run interconnection between CO2 emissions and the regressors. Furthermore, we employ the FMOLS, DOLS and CCR as a robustness check to the ARDL long-run estimator. The study use time-series data spanning from 1971 to 2016. The study also utilizes the wavelet coherence technique to collect information on the association and causal interrelationship among these economic variables at different frequencies and timeframes in Thailand. The study objectives are structured to answer the following questions: (a) does the selected macroeconomic indicators impact CO2 emissions in Thailand? (b) if so, why? Findings reveal; (i) Negative and insignificant link between CO2 emissions and urbanization. (ii) GDP growth affects CO2 emissions positively. (iii) The interconnection between CO2 emissions and energy usage is positive. (iv) Gross capital formation impact CO2 emissions positively. (v) Positive interconnection exists between financial development and CO2 emissions in Thailand. Additionally, the wavelet coherence result provides a supportive evidence for the ARDL long run result. Based on these findings, policy directions were suggested.
Show more [+] Less [-]Assessment of Annual Effective Dose Associated with Radon in Drinking Water from Gold and Bismuth Mining area of Edu, Kwara, North-central Nigeria Full text
2021
Ajibola, T.B. | Orosun, M.M. | Lawal, W. A. | Akinyose, F.C. | Salawu, N.B.
The aim of this paper is to assess the radon concentration of surface and ground waters around Bismuth mining site located in Edu, Kwara State, Nigeria, in order to ascertain its radiological risk. Seventeen (17) water samples were collected and analyzed for radon concentration using a calibrated Rad7-Active Electronic Detector Durridge. The Radon concentration for surface water ranged from 16.23±3.45 Bq/l to 24.71±4.51 Bq/l with a mean of 19.14±3.98 Bq/l while that of ground water ranged from 21.59±3.29 to 27.93±5.74 Bq/l with a mean of 24.16±4.21 Bq/l. The concentration results were used to estimate the annual effective doses. The mean total annual effective dose obtained by summing the dose due to inhalation and ingestion for surface water samples were 187.97 μSvy-1, 257.84 μSvy-1 and 292.77 μSvy-1 for adult, children and infants respectively. Also, the mean effective doses for ground water samples were of 237.25 μSvy-1, 325.44 μSvy-1 and 369.53 μSvy-1 for adult, children and infants respectively. Both the radon concentration and the effective dose due to its inhalation and ingestion were higher than the recommended limit of 11.1 Bq/l and 100 μSvy-1 respectively for all samples. Therefore, consumption of the water in this area poses serious health risk as the water is not safe for all age groups considered. Therefore, it is advised that the water from both sources be treated before consumption.
Show more [+] Less [-]