This study aims to fully integrated and validated spatial temporal statistical model using epidemiological data as a predictive model for surveillance and control of DF cases. Kernel-density estimation (KDE) method was carried out by using spatial union analysis in order to predict and visualize the DF hotspot area by monthly basis in the Subang Jaya area. The generated maps were then verified using Receiver operating characteristics (ROC) was performed to validate the DF hotspot simulation model. Spatial analysis showed that the dengue epidemics in Subang Jaya were spatially dependent. This analysis demonstrated spatial clustering of dengue activity which can facilitate prediction of the magnitude, timing and location of future dengue epidemic. The model developed highlights the adaptation capabilities of the approach where the accuracy assessment result showed accuracy about 60% agreements between the hotspot map and the actual DF location data. It can thus be suggested that any future population increase will be associated with increased DF risk in areas which already accommodate this disease environmentally, climatically and socioeconomically. Future risk could be modelled using the same methods. This would help decision maker in choosing which areas should be under intensive treatment to counter mosquito breeding and reduce prevalence of DF.
Spionid polychaetes, Prionospio are one of the dominant polychaetes in the organically enriched sediment of Sriracha Bay, Chonburi, Eastern coastline of Thailand. This study aims at the bioremediation of organically enriched sediment under green mussel rafts by two spionid polychaetes, Prionospio (Prionospio) membranacea and Prionospio (Minuspio) pulchra. The biomass increment from the two spionids in the bioremediation process revealed that P. (P.) membranacea was significantly more efficient in converting the organic waste to biomass in term of body weight than P. (M.) pulchra. The efficiency of the two polychaetes in the reduction of total organic matter in the sediment was not significantly different. The potential in bioremediation of organic matter in sediment by the two spionids was better than other polychaetes used in the bioremediation of the organic waste from aquaculture system. This study showed that spionid polychaetes P. (P.) membranacea, had the potential for future study as bioremediator species of organically enriched sediment from aquaculture system.
The concentrations of haloacetic acids (HAAs) in both indoor and outdoor swimming pools were assessed for cancer and non-cancer health risks with water samples collected during the summer and rainy seasons from two sources. Results showed that average concentrations of HAA5 (MCAA, DCAA, TCAA, MBAA, and DBAA) in both indoor and outdoor pools ranged from 74.28 to 163.05 µg/L which was higher than USEPA and WHO water quality standards. Cancer and non-cancer risk values of HAA5 exposure from both swimming pool types were acceptable risks based on USEPA recommendation (10 -6-10-4 and <1, respectively). The highest cancer and non-cancer risk values of HAAs exposure were females for indoor pool and children for outdoor pool, respectively. Cancer and non-cancer risk values of HAA5 exposure from outdoor pool were higher than indoor pool and during the rainy season, respectively. Results indicated that monitoring and control of water quality and accumulated organic substance in swimming pools should be followed to maximize health risk reduction from HAA exposure.
This study aims to determine prevalence of microorganisms in the air state and those associated particulate matter (PM) in a hot arid environment (Makkah city, Saudi Arabia) in relation to time of the day, PM concentration and meteorological conditions during the period between July and September 2014. PM and black smoke samples were collected on cellulose nitrate membrane filters during the daytime (8.00 am - 20.00 pm) and the nighttime (20.00 pm - 8.00 am). PMs, filters were eluted in buffer phosphate and aliquots were spread plated onto the surfaces of trypticase soya agar, malt extract agar, and starch casein agar media for counting bacteria, fungi and actinomycetes associated PM, respectively. Airborne microorganisms were collected using an Andersen two stage impactor sampler equipped with Petri plates containing the previously mentioned agar media. The Andersen two-stage viable cascade impactor sampler separates particles into coarse (≥8 µm) and fine (≤8 µm) size fractions. Airborne microorganisms were taken at three day time-scales: in the morning (8 am - 10 am), at the afternoon (13.00 pm - 16.00 pm) and in the evening (22.00 pm - 1.00 am). The average concentrations of PM (149.5 µg/m3) and smoke (57.03 µg/m3) were higher in the daytime and nighttime, respectively. The greatest concentrations of microorganisms associated PM were found in the daytime, however the peak concentration of airborne microorganisms was found in the evening time. Fine microbial fraction constituted ~60% - 75.9% of the total microbial concentrations. Positive correlations were found between bacteria with PM concentration in the daytime and meteorological conditions at the nighttime. Temperature and relative humidity positively affected survivability of microorganisms associated PM at the nighttime and airborne fungi as well. This study helps understand distribution pattern of microorganisms in the atmosphere of a hot-arid environment.
Biosorption is a promising method for removing heavy metals from wastewater, evidenced by several studies on the high efficiency and cost-effectiveness of its practical usage. In the present study, cuttlebone powder (CB-P) and cuttlebone modified via carbonization at 400°C (CB-M400) were used to remove Pb (II) from an aqueous solution. The adsorbents were characterized using a scanning electron microscope (SEM) and an X-ray diffractometer. An adsorption study was carried out at different initial pHs, biosorbent doses, and initial Pb (II) concentrations, in batch experiments in order to evaluate the optimum conditions for Pb (II) removal. The results showed that CB-P obtained a larger specific surface area (8.41 m2/g) than CB-M400 (2.69 m2/g); however, the calcite in CB-M400 displayed a remarkably higher sorption capacity for Pb (II) than the aragonite in CB-P. The carbonization of organic matter in CB-P resulted in a higher calcium carbonate content and the formation of fixed carbon, increasing the adsorption capacity of CB-M400. Optimum conditions for removal of Pb (II) occurred at pH 4.0 with 0.2 g/L of the biosorbent dose. In an equilibrium study, Langmuir’s isotherm was fixed at R2 > 0.9; the maximum capacities were calculated to be 869.57 mg/g for CB-P and 1,573.56 mg/g for CB-M400. In a kinetic study, a pseudo second-order model was fixed; the higher adsorption rate was found in CB-M400.
Arsenic occurs in three common allotrops namely metallic grey, yellow and black. Arsenic founds in shallow aquifer of Ganga and Brahmaputra River Basin. Arsenic contamination in groundwater in the Ganga- Brahmaputra basin in India is reported as arsenic contaminated zone. There are seven highly contaminated states namely-West Bengal, Jharkhand, Bihar, Uttar Pradesh (UP), Assam, Manipur and Chhattisgarh in India. Three districts namely Ballia, Gazhipur and Varanasi in UP are contaminated with very high amount of arsenic. In Ballia district 5 out of 17 blocks are highly contaminated and people are suffering by skin disease related to arsenic. The results depicted that extent amount of arsenic is found in eastern part of Ballia District. The objective of this paper is to study the extent and magnitude of arsenic in groundwater for almost all shallow, medium and deep aquifer of Murli Chhapra Block. Results showed 78% samples are contaminated with arsenic. The contamination rate is in decreasing order by going down(shallow>medium>deep aquifers). In the study area more than 80 percent people have their own hand pump ranged between 12mto 25m in shallow aquifer.
The spatial distribution of plant diversity in Dong Na Tard Provincial Protected Area (PPA) has not been accurately recorded in previously published literature. This study was conducted to assess and evaluate plant species and its correlation with environmental variables. Plot methods coupled with informal community folk interviews were done. Cluster analysis indicated six forest zones which were classified based on Relative Basal Area (RBA) of dominant species. The species composition in each forest zone was significantly influenced by slope, elevation, human disturbance, and distance from the main road to a dense forest. Dipterocarp forests were the most dominance and should be conserved in sustainable manner.
With the advance of GIS technology, hydrology model can simulated at catchment wide scale. The objective is to integrate National Resource Conservation Service (NRCS) Curve Number (CN) with kinematic wave and manning’s equation using GIS to develop a simple GIS-based distributed model to simulate rainfall runoff in Bentong catchment. Model was built using Spatial Distributed Direct Hydrograph (SDDH) concept and applying the time area (TA) approach in presenting the predicted discharge hydrograph. The effective precipitation estimation was first calculated using the NRCS CN method. Then, the core maps that consists of digital elevation model (DEM), soil and land use map in grid. DEM was used to derive slope, flow direction and flow accumulation while soil and land use map used to derive roughness coefficient and CN. The overland velocity and channel velocity estimation derived from combination of kinematic wave theory with Manning’s equation. To capture the time frame, the travel time map was divided into isochrones in order to generate the TA histogram and finally. The creation of SDDH using the TA histogram which will lead to the estimation of travel time for the catchment. Simulated hydrograph was plotted together with the observed discharge for comparison. Six storm events used for model performance evaluation using statistical measure such as Nash-Sutcliffe efficiency (NSE), percent bias (PBIAS) and coefficient of determination (R2;). SDDH model performed quite well as NSE gave result ranging from 0.55 to 0.68 with mean of 0.6. PBIAS indicate that the model slightly over predicted compared to observed hydrograph with result ranges from -46.71 (the most over predicted) to +4.83 (the most under predicted) with average of -20.73%. R2; ranges between 0.55 to 0.82 with mean of 0.67. When comparing the time to peak, (tp), min, and peak discharge, (pd), m3/s, results gave NSEtp 0.82, PBIAStp 0.65, R2tp 0.32, NSEpd 0.95, PBIASpd 14.49 and R2pd 0.98, respectively. Results indicate that the integrated distributed model is successfully applied to the catchment.
Four full-scale systems wastewater treatment plants (WWTPs) were used as study sites. All of these WWTPs were designed and operated for biological nitrogen removal (BNR) by using nitrification-denitrification processes. In general, the WWTPs in Thailand operated at higher values of temperature, HRT and SRT. Influents and effluents from these sites are compared and discussed in terms of BNR, dominant nitrifying microorganisms and WWTP design. Nitrogen removal was observed in all the sites and correlated to the influent total N to BOD ratio. Polymerase chain reaction coupled with denaturing gradient gel electrophoresis was used to identify dominant bacteria involved in nitrogen transformations: ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB), and nitrate reducing bacteria (NRB). AOB Nitrosomonas sp. was found only in Thailand where aerobic HRT was ≥ 4 hours and SRT was ≥15 days. Furthermore, AOB Nitrosospira sp. were found only in Japan at aerobic HRT ≤ 4 hours and SRT≤ 13 temperature (21-27°C). NOB Nitrospira sp. was found at aerobic HRT ≥ 4 hours and SRT ≥ 6 days. Interestingly, Nitrotoga sp. was found in the aerobic tank one in Thailand and one in Japan and co-occurred with NRB Burkholderia denitrificans. The higher wastewater temperature and lower influent nitrogen concentration in Thailand appear to promote a different AOB and NOB community structure than in Japan. The most important factor affecting TN removal was the influent TN to BOD ratio.
Distribution of 10 polycyclic aromatic hydrocarbons (PAHs) in the gas phase of air from selected indoor and outdoor areas of Selangor and Malacca, Malaysia has been investigated. A locally designed Semi Permeable Membrane Device (SPMD) was applied for passive air sampling for 37 days at selected locations. Cleanup was carried out with Gas Purge - Micro Syringe Extraction (GP-MSE) and the final analysis was using Gas Chromatography-Mass Spectrometry (GC-MS). In this study, 6 indoor and 12 outdoor locations were selected for air sampling. A total of 10 compounds of PAHs (Ʃ10PAHs) were determined in the range of 0.218 ng/m3 - 1.692 ng/m3 and 0.378 ng/m3 - 1.492 ng/m3 in outdoor and indoor samples respectively. In the outdoor samples, locations such as near a petrol station and heavy traffic showed the maximum levels of Ʃ10PAHs, while rooftop samples showed the lowest Ʃ10PAHs. The distribution of gas phase Ʃ10PAHs was influenced by vehicular emission. Low molecular weight (LMW) compounds (2-3 rings) were dominant in all samples (>70%) indicating that SPMD has successfully sampled the gas phase of the air.
Natural thorium radioisotopes (232Th, 230Th, 228Th, 234Th) are well known to be particle reactive, thus they are often used to study the geochemical process of particle reactive matter. In this study, water samples were collected from Langkawi Island and Pangkor Island from six and ten sampling stations respectively, to determine the activity of 232Th, 230Th and 228Th in dissolved (DISS) and suspended particulate matter (SPM) phases, and estimate the sources and origin of SPM into the marine environment. The results in terms of volume activity concentration (mBq/L) shows that the activity level of 228ThDISS was higher than 228ThSPM at all sampling stations possibly due to the behaviour of the 228Th parent, 228Ra which is easily desorbed from SPM. At several stations far from the coast; stations L4 (4.58km), P7 (3.16 km), P6 (2.1 km), P10 (1.38 km), the activity of 232ThDISS was higher compared to 232ThSPM. These stations behave the same way as the open ocean in which 232ThDISS is contributed by atmospheric dust. Indeed, the partition of thorium between dissolved and SPM phase can be used to detect anthropogenic organic pollution as in station L6 in which thorium activity in dissolved phase is higher compared to in SPM phase. Moreover, the use of the (232Th/230Th)SPM ratio is useful to detect lithogenic input to the marine environment in which the ratio ranges from 0.13 to 0.5 and 0.7 to 3.16 for stations that are far and near to the coast respectively, except for station P1. However the data analysis shows that there is no clear pattern of kd values at both sampling sites, probably due to the adsorption and desorption processes of 232Th and 230Th that occurs in the water column. Nevertheless, as the SPM concentration (mg/L) increases, the kd value decreases except for the activity of 228Th which shows a strong negative correlation with SPM.
Climate change gives impact on extreme hydrological events especially in extreme rainfall. This article discusses about the relationship of rainfall distribution and water level on major flood 2014 in Pahang River Basin, Malaysia in helping decision makers to flood management system. Based on DID Malaysia rainfall station, 56 stations have being use as point in this research and it is including Pahang, Terengganu, Kelantan and Perak. Data set for this study were analysed with GIS analysis using interpolation method to develop Isohyet map and XLstat statistical software for PCA and SPC analyses. The results that were obtained from the Isohyet Map for three months was mid-November, rainfall started to increase about in range of 800mm-1200mm and the intensity keep increased to 2200mm at mid-December 2014. The high rainfall intensity sense at highland that is upstream of Pahang River. The PCA and SPC analysis also indicates the high relationship between rainfall and water level of few places at Pahang River. The Sg. Yap station and Kg. Serambi station obtained the high relationship of rainfall and water level with factor loading value at 0.9330 and 0.9051 for each station. Hydrological pattern and trend are extremely affected by climate such as north east monsoon season that occurred in South China Sea and affected Pahang during November to March. The findings of this study are important to local authorities by providing basic data as guidelines to the integrated river management at Pahang River Basin.
This study aimed to find the optimum condition to prepare activated charcoal from spent coffee ground and to examine the adsorption efficiency of the BTEX released from water and oil base paints. The optimum condition was found to be carbonization at 400℃ for 1 h, followed by activation with H3PO4 at a 1:1 (w/w) impregnation ratio and then carbonized at 700℃ for 1 h. This condition gave the highest iodine number (300.6 ± 5.1 mg/g), Brunaeur-Emmett-Teller (BET) surface area (1,769 m2/g), pore width (0.7947 nm) and pore volume (0.7517 cm3/g). The efficiency of the activated charcoal to adsorb the benzene and toluene emitted from normal and low volatile organic compounds water base paints was 99.8% and 99.7%, respectively. Furthermore, the adsorption efficiency of the activated charcoal from spent coffee ground (96.99 ± 0.54%) to remove the total BTEX released from oil base paints was higher than that achieved with the charcoal without chemical activation (66.97 ± 2.11%) or without carbonization (51.83 ± 10.32%). The produced activated charcoal from spent coffee ground by chemical activation was suitable for use as an adsorbent of the BTEX released from water and oil base paints.
Krabi coal-fired power plant is the new power plant development project of the Electricity Generating Authority of Thailand (EGAT). This 800 megawatts power plant is in developing process. The pollutants from coal-fired burning emissions were estimated and included in an environmental impact assessment report. This study aims to apply air quality modeling to predict nitrogen dioxide (NO2) and sulfur dioxide (SO2) concentration which could have health impact to local people. The health risk assessment was studied following U.S. EPA regulatory method. The hazard maps were created by ArcGIS program. The results indicated the influence of the northeast and southwest monsoons and season variation to the pollutants dispersion. The daily average and annual average concentrations of NO2 and SO2 were lower than the NAAQS standard. The hazard quotient (HQ) of SO2 and NO2 both short-term and long-term exposure were less than 1. However, there were some possibly potential risk areas indicating in GIS based map. The distribution of pollutions and high HI values were near this power plant site. Although the power plant does not construct yet but the environment health risk assessment was evaluated to compare with future fully developed coal fire plant.
Given the complexity and heterogeneity of mangrove conservation landscape, research gaps still exists to quantify sulfate and total sulfide and their relationships with sediment properties and environmental covariates. Thirty-two sediment samples in the top layers (0-10 cm) were analyzed to assess biochemical properties, sulfate and total sulfide contents. With an average±SD value of 0.62±0.36 mg/g, the total sulfide content from the study site was high compared to the southern part of Thailand. The distribution of sulfate content exhibited high values in nearby land area which gradually reduced in seaward discharges/runoff, whereas high concentrations of total sulfide were highlighted around the center of the study site and vertically accumulated in the top few centimeters of soil and decreased with depth. The most pronounced factor affecting the amount of sulfate and total sulfide content was organic matter, while pH, organic carbon, potassium, salinity, and sediment-mangrove conditions correlated with sulfate and sulfide at different levels. Total sulfides concentration can be considered as indicator of over nutrient-rich sediments for assessing environmental quality perhaps the die-back of mangroves. Concerns about high total sulfide concentrations across mangrove conservation areas should receive more attention, in particular the reduction of OM from the anthropogenic source.
Photocatalytic degradation of 2,4-dichlorophenol (2,4-DCP) contaminant in water was investigated. Composite SnO2/TiO2 films N-doped to varying degrees were prepared via sol-gel method, and coated on glass fibers by dipping method. The effects of nitrogen-doping on coating morphology, physical properties, and glyphosate degradation rates were experimentally determined. Nitrogen-doping shifted absorption wavelengths and narrowed the energy band gap, enhancing photocatalytic performance. The maximum efficiency of 2,4-DCP degradation was up to 93.65% for 12 h of 40N/SnO2/TiO2 composite film. The near optimal 40N/SnO2/TiO2 composite thin film exhibited about 4 folds degradation rates relative to pure TiO2, and should perform well in water purification applications.
The effect of γ-polyglutamic acid (PGA) produced by Bacillus subtilis on cadmium (Cd)-damaged rice was investigated in experiments with pots containing soil contaminated with Cd at a concentration of 0-200 mg/kg and PGA at a concentration of 0-500 mg/kg. Although Cd reduced the growth and productivity of rice in comparison to the control, the addition of 500 mg/kg of PGA alleviated the effects of Cd toxicity in rice, resulting in increases in shoot and root lengths, the vigor of the rice and the number of seeds per panicle. Micrographs of ultrathin sections of root cells showed that the addition of 500 mg/kg of PGA decreased Cd accumulation in both the epidermis and the intracellular space of cortex, suggesting that PGA reduced Cd transportation into root cells. Based on these results and the metal-binding characteristics of PGA, it is conceivable that the mechanism by which PGA alleviates Cd toxicity is the extracellular formation of Cd-PGA complexes.
The objective of this study was to investigate the physical characteristics of watershed, water storage capacity, and dynamic modeling development for generating the water storage capacity necessary to dilute waste water from land utilization in the Upper Tha Chin Watershed (UTCW) within three scenarios: existing land use condition, expected land use change in the year 2020, and regulating water storage to dilute Biochemical Oxygen Demand (BOD). The Soil and Water Assessment Tool (SWAT) model was applied in order to estimate the amount of the streamflow, suspended sediment, soil loss, and BOD based on the observed land use and water release data from the reservoir, from January, 2013 to December, 2014 as presented in Scenario 1. The reliability of the model was calibrated with the observed data by adjusting the coefficient of the key parameters through SWAT calibration uncertainty procedures (SWAT-CUP) and validating the observed data from seven hydrologic stations. The goodness of the calibration results was assessed based on the coefficient of determination (R2), Nash-sutcliffe efficiency coefficient (NSE), and mean squared error (MSE); along with simulating the impact of land utilization in the year 2020, and the drainage simulation of the Krasiao reservoir on BOD. The results obtained from the SWAT model found that the UTCW area was 5,253.96 km2 with a stream length of 1,906 km, 14 sub-watersheds and 286 hydrological response units (HRUs). The application of the SWAT model in Scenario 1 indicated that the streamflow was 374.74 million cubic meter (MCM), suspended sediment was 1,854,720 tons/year, soil loss was 91.35 tons/ha/year, and BOD was 2.70 mg/L. The simulation of Scenario 2, forecasting the expected land use change in year 2020, showed that the amount of the streamflow decreased to 65.09 MCM, suspended sediment increased to 5,065,446 tons/year, soil loss increased to 240.96 tons/ha/year, and BOD was 2.70 mg/L; when compared with Scenario 1. The simulation of Scenario 3, regulating water storage for diluting waste water, found that BOD during the dry season of December, January, February, and March was 3.08, 3.24, 1.52, and 2.70 mg/L, respectively; and a decrease to 1.50 mg/L with an increased drainage of the Krasiao reservoir. This study shows that the SWAT model successfully stimulated and assessed the effects of land use activities on streamflow, sediment, and BOD; including the successful drainage of the Krasiao reservoir in both watershed and sub-watershed areas.
This laboratory-scale study employed sequencing batch reactor (SBR) technology to investigate the effect of two operational parameters [i.e. solids retention time (SRT) and anoxic time ratios] regarding the treatment of a slaughterhouse wastewater. Results indicated that organic matter removal, expressed as chemical oxygen demand (COD), was very high, consistently exceeding the 95 % level. In addition, the total nitrogen (TN) removal ranged between 82 and 94 %, while total phosphorus (TP) removal fluctuated between 88 and 94 %. In general, the reactors exhibited a high degree of operational stability during treatment. Although the investigated range of the two operational parameters appeared to have a minimal effect on the process performance (expressed as % carbon or nutrient removal), the corresponding COD and TN specific consumption rates were noticeably affected by the variation in the anoxic time ratios. Furthermore, the operating cycle length of 8 h employed in this study resulted in improved performance, in terms of nitrogen removal, compared to other studies conducted at longer operating cycles.
Pressure on infrastructure due to over population has deteriorated the indoor environment causing various health issues. It has also contributed to the sick building syndrome making huge monetary burden to economy. Public health department of the country has taken many actions to mitigate these issues however; design of the building was not taken into consideration. Optimum quantities of light and proper ventilation express the quality of indoor environment. Also, the use of natural light and ventilation is definitely an advantage with the raising concerns regarding the cost and environmental impact of energy use. Natural light and ventilation can reduce building construction and operation costs and reduce the energy consumption. Moreover it would also ensure safe, healthy and comfortable living conditions. Therefore, it is very important to assess indoor environment before implementing new construction or building. This provides theoretical guidelines and basic calculations for understanding a green infrastructures and the factors related to it. In this paper, a building has been studied in an urban city of India where the percentage area of light and ventilation were analyzed Analysis showed the percentage of light is thrice and ventilation is twice the prescribed limits by Indian Green Building Council (IGBC). It has been found that building under study fulfills the given criteria by IGBC. This analysis can be useful while constructing a new infrastructure to improve the standard of living as 90% time is spent indoors.
