Journal Issue: EnNRJ Vol. 20 No. 4
Issued Date
2022
Resource Type
Language
tha
eng
eng
File Type
application/pdf
Access Rights
open access
Rights
ผลงานนี้เป็นลิขสิทธิ์ของมหาวิทยาลัยมหิดล ขอสงวนไว้สำหรับเพื่อการศึกษาเท่านั้น ต้องอ้างอิงแหล่งที่มา ห้ามดัดแปลงเนื้อหา และห้ามนำไปใช้เพื่อการค้า
Rights Holder(s)
Faculty of Environment and Resource Studies Mahidol University
Journal Volume
EnNRJ Volume 20
(2022)
Articles
Phosphorus Recovery and Bioavailability from Chemical Extraction of Municipal Wastewater Treatment’s Waste Activated Sludge: A Case of Bangkok Metropolis, Thailand
(2022) Kay Thi Khaing; Chongchin Polprasert; Suwisa Mahasandana; Wanida Pimpeach; Withida Patthanaissaranukool; Supawadee Polprasert
This study evaluated the extractability and bioavailability of Phosphorus (P) recovered from waste activated sludge (WAS) so as to reduce dependence on the import of non-renewable P resources. P extraction was carried out using sulfuric acid (H2SO4). A response surface methodology was used to optimize conditions for the chemical leaching of WAS. The results showed the optimum condition for leaching WAS with 0.1 mol/L H2SO4 for 30 min, resulting in 97% P released. The efficiency of P recovery by P precipitation was associated with pH value and Mg:P. At pH 7, 9, and 11, P recovery was 92, 92, and 91% with uncontrolled Mg and 93, 93, and 92% with sea salt (Mg:P, 2:1), respectively. However, the yield of the produced struvite was much lower compared with that of added sea salt. From elemental analysis, the yield of struvite precipitated at pH 9 of Mg:P, 2:1 was about 26%, and the total P content of the precipitate was 12%. Available P was almost 80% after 35 days of operation, which was higher than that of commercial fertilizers. Results of this study are expected to provide fully comprehensive information to decision-makers regarding the suitability of implementing P-composite matter recovered from WAS. This will also help close the loop of the P cycle for food cultivation in the human ecosystem.
Simulation of PM2.5 Concentrations around the Proposed Yangon Outer Ring Road (Eastern Section) in Myanmar Using CALINE 4 Model
(2022) Shwe Sin Ko Ko; Ranjna Jindal; Win Trivitayanurak; Kraichat Tantrakarnapa; Nawatch Surinkul
An increase in traffic volume has resulted in the deterioration of environmental quality and human health in Yangon as well as in the surrounding areas that are connected to the city via several road links. The Yangon Outer Ring Road Construction (YORR) (Eastern Section) is a priority project for solving traffic-related problems. This study aimed to simulate the current levels of PM2.5 concentration around the proposed YORR (Eastern Section) area using the CALINE 4 model and to evaluate the model’s performance. Air quality measurements of PM2.5 were carried out in five townships around the proposed road construction area-for one week at each monitoring location-from January 24th to March 2nd, 2021 using the Haz-Scanner Environmental Perimeter Air Station. When compared to the ambient air quality guidelines of Myanmar, the International Finance Corporation, and the World Health Organization, the observed PM2.5 concentrations were found to be usually high at all locations, except in Kyauktan township. Statistical analysis indicated that the CALINE 4 model performed satisfactorily with a coefficient of determination of 0.85-0.90, fractional bias of 0.03-0.50, and normalized mean square error of 0.001-0.100. It is crucial that mitigation measures, including policies regarding the use of low PM emission vehicles and road-side barriers, be implemented by regulatory authorities during and after the YORR construction.
Color Removal of Pulp and Paper Mill Wastewater Using Residual Eucalyptus Wood
(2022) Kanjana Yupin; Thanakrit Neamhom; Chatchawal Singhkant; Siranee Sreesai; Supawadee Polprasert
This study investigated the color removal efficiency of pulp and paper mill wastewater using residual eucalyptus wood as a method to minimize the solid wastes generated from pulp and paper processes. The activated carbon used in this study as the color adsorbent was produced from residual eucalyptus wood. The carbon was activated with phosphoric acid and carbonized in a furnace at 500°C for 60 min. Effects of types and amounts of activated carbon on color removal efficiency were evaluated. Three types of solid wastes, consisting of wood chip, bark, and mixed wood (wood chip:bark, 1:1), were investigated at a loading of 1, 3, 5, and 7 g/100 mL under contact times of 30, 60, 90, and 120 min. The results showed that 7 g of wood chip activated carbon/100 mL under all contact times gave color removal efficiency of 94-97%. However, the highest adsorption capacity of 216 ADMI/g occurred at 1 g of adsorbent used. Freundlich isotherms were satisfactorily fitted to experimental data for the best condition with high correlation coefficients. The color removal efficiency depended on surface area, pore volume, structure, and characteristics of the activated carbon.
Title
EnNRJ Vol. 20 No. 4
Author's Affiliation
Mahidol University. Faculty of Environment and Resource Studies
มหาวิทยาลัยมหิดล. คณะสิ่งแวดล้อมและทรัพยากรศาสตร์
มหาวิทยาลัยมหิดล. คณะสิ่งแวดล้อมและทรัพยากรศาสตร์
Keyword(s)
Climate change
Biodiversity
Disaster
Ecological
Environmental modelling
Environmental dynamics
Environmental pollution
Emerging contaminants
Transboundary pollution
Waste and wastewater treatments
Hazardous wastes
Natural resource management
Multidisciplinary sciences
Environment and Natural Resources Journal
Biodiversity
Disaster
Ecological
Environmental modelling
Environmental dynamics
Environmental pollution
Emerging contaminants
Transboundary pollution
Waste and wastewater treatments
Hazardous wastes
Natural resource management
Multidisciplinary sciences
Environment and Natural Resources Journal