A geophysical survey was conducted to investigate contamination in a domestic waste-disposal site, at Ampar Tenang, Dengkil, Selangor. The objectives of the survey were to delineate and identify pathways for contaminant migration. Surface geophysical method employing 2-D DC resistivity imaging technique was used to locate potential leachate plumes. A total of six lines of 2-D resistivity images were established with three of them located on the waste pile while the other three situated outside the boundary of the dumping site. The objectives were successfully met, including delineation of buried waste and identification of the positions of contaminated subsurface soil and groundwater. In general the result of the survey shows that the resistivity value of the decomposed waste material is relatively low compared to those of the uncontaminated soil outside the dumping site. The electrically conductive anomaly on the dumping site was interpreted as leachate plumes which appears to have seeped at depth as far as 20 m below surface. Near surface low resistivity layer observed on the area east of the dumping site is interpreted to be associated with leachate runoff.
The present study explored the synthesis of Kaolin-nano scale zero-valent iron composite (K-nZVI) by using chemical reduction method.Sorption characteristics of the K-nZVI for the removal of Cu(II) ions was studied in batch conditions.The physical and chemical structure of the K-nZVI composite was characterized by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-XRF), X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Brunauer-Emmett-Teller studies (BET).The effect of pH, the initial metal ion concentration, and contact time on adsorption of Cu(II) onto K-nZVI was investigated.The K-nZVI exhibited good sorption performances over the initial pH range from 2.5 to 6.5.The kinetics data was studied by applying two sorption kinetic models (Pseudo-first and Pseudo-second-order) equations.The pseudo-second-order model was relatively suitable for describing the adsorption process.The equilibrium adsorption data is well fitted to Langmuir adsorption models.The maximum adsorption capacities of K-nZVI sorbent as obtained from Langmuir adsorption isotherm is found to be 178-200 mg g -1 for Cu(II).Sorption isotherm models (Langmuir and Freundlich) were applied to the experimental data.The adsorption kinetics was well represented by the pseudo second order rate equation, and the adsorption isotherms were better fitted by the Langmuir equation.The thermodynamic studies showed that the adsorption reaction of Cu(II) is endothermic processes.TheK-nVZI having number of features including easy preparation, environmentally friendly nature, low-cost and good sorption performance enable K-nZVI application in industrial purpose specifically in the field of industrial water treatment.
The most prominent threats to the main water resource in north east Kelantan, is the intrusion of salt water especially in the second aquifer and part of the third aquifer. The main purpose of this work was to evaluate the salt water intrusion into the first aquifer. It was investigated using physical and chemical characteristics of ground water, which revealed that. A range of pH from 4.95 7.63, electrical conductivity (EC) 70 ̶ 2561 µs/cm, salinity 0.02 ̶ 1.21, and total dissolved solids 0.025 ̶ 1.73 mg/l. A range of calcium (Ca), sodium (Na), chloride (Cl) and sulfate (SO4) 1.51 ̶ 37.41, 2.11 ̶ 78.92, 2.84 ̶ 575.2 and 0.92 ̶ 172.82 mg/L respectively. The values of Na, Ca, SO4, Cl and EC were decrease gradually from the sea towards inland and vice versa. A variation in ground water levels between the dry and wet seasons which were in the range of 0.2 ̶ 1.97 m. Moreover, the freshwater/saltwater interface was located on the shoreline in the dry season and retreated in the wet season. Generally, the salt water intrusion was discovered in the first coastal aquifer; however, it has affected a small area. The ground water in this aquifer is fresh (except the three wells 11, 19 and 20) that considered as salty due to the high average of chloride, salinity, total dissolved solids, and electrical conductivity.
This study explores an intensive investigation of the effect of cationic surfactant, cetyltrimethylammonium bromide (CTAB) on biosorption of Acid Blue 25 (AB25), an anionic dye, onto Bengal gram fruit shell (BGFS) from aqueous solution.The BGFS was characterized using Fourier transform infrared spectroscopy and scanning electron microscopy.Effect of AB25 and CTAB concentrations, time and temperature, were explored.The dye uptake by the BGFS was increased with increasing initial dye concentration up to 100 mg L -1 .The inclusion of 0.9 mmol L -1 of CTAB in the biosorption medium was greatly improved for the removal of AB25.The AB25 uptake was better described by the Langmuir adsorption model than the Freundlich model.This study shows that the maximum uptake of AB25 dye by BGFS in the absence of surfactant was evaluated and found 29.4 mg g -1 .Also, the results of this investigation revealed that the presence of 0.9 mmol L -1 CTAB in the biosorption medium increased the maximum uptake of AB25 to 166.6 mg g -1 , which is 5.7 times higher than the uptake capacity in the absence of CTAB.The biosorption kinetics was correctly described by the pseudo-second-order kinetic model for all cases studied a confirmation that a chemisorption process controlled the biosorption rate.Thermodynamic parameters (ΔH°, ΔS°, and ΔG°) were determined for the biosorption of AB25 onto BGFS-CTAB.The biosorption process describes that the reaction was exothermic and spontaneous processes.
Abstract Climate change is expected to result in intensifying extreme weather that would increase the risks of climate hazards; leading to natural hazards triggering technological disasters (Natech) events. This paper highlights a simple method using easily available information to identify potential sites for Natech associated with climate change based on a case study of the Selangor River Basin in Malaysia. The approach draws heavily on susceptibility modelling, in combination with screening processes to delineate exposed potential point sources, followed by field inspection to validate the information. Findings reveal that with the onset of climate change, over 55% of the manufacturing industries in the Selangor River Basin are exposed to the risk of Natech due to floods and coastal inundation. The approach can be applied to river basins where industrial activities are prevalent and local information on future climate conditions is limited. It is useful for raising awareness, providing early warning of emerging hazards in worst-case scenarios, and prioritizing climate actions on Natech risk due to climate change.
The presence of dyes in water sources that act as contaminants is hazardous to human and animal health. Therefore, this research was conducted on the removal of methylene blue (MB) using granitic residual soil-supported nano zero-valent iron (Gr-nZVI), to examine its potential use as an efficient adsorbent. Batch adsorption experiments were conducted in this study to examine the impact of initial dye concentration, contact time, dosage, pH and temperature effets. Based on the results, it can be inferred that Gr-nZVI (with Kd=0.1 L/g and R2 =1) exhibits superior adsorption of MB at higher metal ion concentrations when compared to granitic residual soil (Gr) (with Kd=0.0588 L/g and R2 =0.9267). The removal percentage of Gr-nZVI was found to be 100%, obtained at 100 mg/L MB ion concentration. Sorption data have been correlated with both Langmuir and Freundlich adsorption models. However, the Langmuir isotherm was the only model that showed a good fit for the adsorption of MB on Gr-nZVI. The mechanistic phases of the process were determined through kinetic energy studies. Kinetic data showed the removal of MB was 100% within 5 min for both Gr-nZVI and Gr. This indicates the very fast adsorption of MB and data followed a pseudo-second order. According to adsorption analysis, Gr demonstrated a higher adsorption capacity for MB removal compared to Gr-nZVI and nZVI. This study also highlights that nZVI does not facilitate MB adsorption, making the composite nZVI unnecessary due to Gr is capable of removing MB on its own.
Euler Deconvolution technique was successfully used on the satellite gravity data to discover about 270 fault lineaments distribution as well as their dip directions and extensions below the surface. The traced lineaments are overlapped partially on the major known faults, which can be used in proving the existence of the fault by Euler Deconvolution technique. Extra information supplied by this technique in terms of mapping and cross-section include trends of major and unknown faults as well as their dipping angle and direction. In addition, this technique can be used to determine the approximate depth of each fault zone, which is impossibly measured on the field.
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