Effect of EDTA and DTPA on Cadmium Removal from Contaminated Soil with Water Hyacinth

The effects of ethylenediaminetetraacetic acid (EDTA) and diethylene triaminepentaacetic acid (DTPA) on cadmium (Cd) uptake by water hyacinth (Eichhornia crassipes) in Cd-contaminated soil was studied. Experimental samples were separated into 4 treatment groups: 1) Untreated control, 2) EDTA addition, 3) DTPA addition, and 4) mixture of EDTA and DTPA (1:1) addition. The plants were harvested at 20, 40, 60, 80 and 100 days. Cd levels were measured in soil samples, water samples and two parts of the plant: shoot (stem and leaves) and root. The results showed that Cd accumulation in plants with added EDTA and DTPA were higher than the control set, indicating that EDTA and DTPA addition increased Cd uptake by water hyacinth. Cd accumulations in the root in all groups were significantly (p < 0.05) higher than that in the shoot. In EDTA added sets, Cd accumulation in the root was higher than in shoots and were measured at 160.91 and 13.37 mg kg-1 at 100 d, respectively. This research indicates that DTPA was most suitable for increasing the cadmium removal capacity of water hyacinth and offers a suitable phytoremediation technique to help clean contaminated sites

Comparison of CO2 Emissions from Vehicles in Thailand

Emission of carbon dioxide (CO2), a greenhouse gas, from typical passenger vehicles in Thailand was investigated using a chassis dynamometer in the Automotive Emission Laboratory. The vehicle running method was controlled under the standard Bangkok driving cycle. CO2 emissions were measured at three different speeds for the following four vehicle types commonly used in Thailand: heavy duty diesel (HDD), light duty diesel (LDD), and light duty gasoline (LDG) vehicles and motorcycles (MC). HDD vehicles had the highest average CO2 emission rate, followed by LDD, LDG and MC at 1,198.8±93.1, 268.4±21.3, 166.1±27.7 and 42.5±6.1 g km-1, respectively; all values were significantly different (p < 0.05) from each other. The effect of different fuel types, including diesel, gasoline 91, gasohol 95, gasohol 91, liquid petroleum gas (LPG) and natural gas for vehicles (NGV), on the CO2 emission level was also compared. HDD vehicles had a higher rate of CO2 emission when using either NGV or diesel, while LDD vehicles emitted more CO2 with diesel than with NGV. For LDG vehicles, more CO2 was emitted with gasohol 91 than with gasohol E20, LPG or NGV. Finally, MC had a higher average CO2 emission rate with gasohol 95 than with gasoline 91 and gasohol 91 at any vehicle speed. The CO2 emission rates obtained in this study can be used as a basis to create a database that supports development of an efficient transportation management system and reduced vehicular emission of greenhouse gases in Thailand

Use of organic fertilizer on paddy fields to reduce greenhouse gases.

ABSTRACT: This study analysed the effect of organic fertilizer on greenhouse gas emissions, including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), resulting from paddy field farming. Suphanburi 1 rice varieties were planted in a double-crop organic rice field at Pathum Thani Rice Research Centre, Pathum Thani Province, Thailand. The paddy was divided into 4 plots, as follows: (1) control plots without added fertilizer, (2) plots with the addition of organic fertilizer (cow manure), (3) plots with the addition of organic fertilizer pellets, and (4) plots with the addition of chemical fertilizers. The results showed that the CO2, CH4, and N2O emission rates in the chemical fertilizer plot were the highest at 534, 1.79, and 1.21 mg m −2 day −1 , respectively. The second highest levels were with the addition of manure at 377, 1.35, and 0.88 mg m −2 day −1 , respectively. To help reduce greenhouse gas emissions from rice farming, it is recommended that organic fertilizer be used instead of chemical fertilizer, a practice that will also benefit the farmers&apos; health

Effect of Organic Fertilizer on Cadmium Uptake by Rice Growing in Contaminated Soil

The effects of organic fertilizer on the cadmium uptake by rice growing in contaminated soil were studied in a nursery experiment. The types of soil used were uncontaminated and fertilizer free, contaminated and fertilizer free, contaminated and organically fertilized at 3.25 ton/ha, contaminated and organically fertilized at 6.25 ton/ha and contaminated and organically fertilized at 12.5 ton/ha. Four varieties of Thai rice, Khao Dawk Mali 105 (KDML105), RD6, Phitsanulok3 and Niaw San-Pa-Tong, were planted in each container. Samples of the soil and plants, consisting of the above-soil growth, below-soil growth, husk and grain, were taken every 30, 60, 90 and 120 days to determine the amount of cadmium uptake in each part. After 120 days, the results showed that the Niaw San-Pa-Tong variety grown in the contaminated soil with organic fertilizer at 12.5 ton/ha displayed the lowest accumulated cadmium uptake in the above-soil parts, at 4.1 mg/kg, whereas Phitsanulok3 grown in the contaminated soil and fertilized at 6.25 ton/ha showed the lowest cadmium uptake in below-soil parts, at 9.19 mg/kg. The lowest level of cadmium deposited in the grain, at 0.06 mg/kg, was found in the Phitsanulok3 cultivar growing in the contaminated soil fertilized at 12.5 ton/ha. With regard to the accumulative cadmium uptake, we propose that a concentration of organic fertilizer ranging between 6.25-12.5 ton/ha produces the best results

Efficiency of sodium phytate in the remediation of As, Mn, and Cu contamination in acid mine drainage using water hyacinth

The accumulation and uptake efficiency of heavy metals, including As, Mn, and Cu, in water hyacinth (Eichhornia crassipes (Mart.) Solms) grown in synthetic acidic wastewater supplemented with sodium phytate (SP) was examined. Three treatments were studied using synthetic acidic wastewater containing 0.25, 5.0, and 1.0 mg/L of As, Mn, and Cu, respectively, (SM + heavy metals) and having pH in the range of 4–6, which comprised of (1) control treatments using SM + heavy metals at pH 4, 5, 6 without SP, and treatments using SM + heavy metals at pH 4, 5, 6 with SP: Cu (2) in a 1:3 M ratio and (3) a 1:6 M ratio. The translocation factor (TF < 1) indicated that plants had a lower capacity to transport heavy metals from the roots to the stems. The shoots of water hyacinth exhibited the highest capacity to absorb and store As in the pH 4-treatment with SP (SP:Cu1:3 mol), whereas the roots showed the greatest capacity at pH 4 without SP. The roots and shoots of the water hyacinth showed the greatest capacity to take up and store Mn in the pH 5-treatment with a 1:3 M ratio of SP:Cu. The roots showed the greatest capacity to take up and store Cu in the pH 6-treatment, and the shoots showed the highest capability in the pH 5-treatment with 1:3 M ratio of SP:Cu. Moreover, analysis of the chemical forms revealed that As accumulated in the arsenate form, whereas Mn accumulated in the divalent form

Carbon dioxide and methane emission rates from taxi vehicles in Thailand

Due to the expansion of urban areas have been increasing levels of greenhouse gas emissions from taxi and passenger cars that use natural gas for vehicles (NGV) and liquid petroleum gas (LPG) as alternative fuels . The objective of this study was to evaluate the CO2 and CH4 emission of NGV and LPG taxis with different times from their engine ages compared to those from passenger cars. The driving tests were conducted at three driving speed ranges in Bangkok, Thailand. No significant differences in the CO2 emission rates from taxis and passenger cars using either NGV or LPG (174.5–227.0 g/km) were found. However, NGV taxis emitted the highest CH4 at all driving speeds, with an average emission of 1.33 g/km, higher than that from the LPG taxis. Comparing between taxis and passenger cars, the NGV taxis emitted the highest of CO2 and CH4 (13.8 ton CO2-eq/y), followed by LPG taxis (12.5 ton CO2-eq/y). The results obtained in this study can be used to create a database that supports the decision-making on development projects and to control GHG emission in Thailand

Air Quality Monitoring around the Developed Area of Chulalongkorn University in Kaeng Khoi District, Saraburi Province

The construction project for the developed area in Kaeng Khoi District, Saraburi Province, Thailand, drafted by Chulalongkorn University has raised various concerns over environmental impacts, particularly relating to public health and air quality. In order to investigate impacts of this project, air quality sampling was conducted in Tan Diew Sub-district, Huai Haeng Sub-district, Cham Pak Paew Sub-district and some surrounding sites of Chulalongkorn developed area by gravimetric method using a high volume air sampling machine. Two types of particulate matter including total suspended particulate matter (TSP) and particulate matter < 10 µm (PM10) were continuously monitored during all 3 seasons for a study period of 3 years in order to compare the effect of seasonal variation on the amount of particulate matter generated in each study area, to study the correlation between TSP and PM10, and finally to identify other causal factors related to particulate levels. Results from this study indicated that TSP and PM10 both reached the highest in winter followed by summer and appeared to be at the lowest level during the rainy season. In addition, causal factors such as wind direction and human activities also influenced particulate levels in each study area