Mohamad Hidayat Jamal

Removal Rate of Organic Matter Using Natural Cellulose via Adsorption Isotherm and Kinetic Studies.

In this study, the removal of natural organic matter (NOM) using coconut fiber (CF) and palm oil fiber (POF) was investigated. Preliminary analysis was performed using a jar test for the selection of optimal medium before the fabricated column model experiment. The equilibrium studies on isotherms and kinetic models for NOM adsorption were analyzed using linearized correlation coefficient. Results showed that the equilibrium data were fitted to Langmuir isotherm model for both CF and POF. The most suitable adsorption model was the pseudo-first-order kinetic model for POF and pseudo-second-order kinetic model for CF. The adsorption capacities achieved by the CF and POF were 15.67 and 30.8 mg/g respectively. Based on this investigation, it can be concluded that the POF is the most suitable material for the removal of NOM in semi polluted river water.Al Asfar Lake is a shallow wetland and habitat for wildlife and birds in a desert environment. The water of this lake is originated from the drainage water collected by earthen drainage network and discharged into the lake. The purpose of this study was to assess physico- chemical characteristics and some of heavy metals in Al Asfar lake water. The studied parameters are iron, manganese, copper, zinc, cadmium, chromium, lead, pH, electrical conductivity, and nitrate. Forty-five surface water samples were collected in March 2013. The results revealed that the pH ranged from 7.33 to 8.67, electrical conductivity ranged from 8.28 to 11.34 dS/m, and NO(3)(-) ranged from 0.84 to 2.29 mg/L. In addition, heavy metals concentrations in water were found in the following order: Fe > Mn > Cu > Zn > Cd > Cr = Pb. The mean concentrations of heavy metals in surface water of Al Asfar lake ranged from 0.027 to 0.159 ppm, 0.007 to 0.142 ppm, 0.005 to 0.017 ppm, 0.005 to 0.066 ppm, 0.001 to 0.033 ppm, 0 ppm, and 0 ppm for iron, manganese, copper, zinc, cadmium, chromium, and lead, respectively. Moreover, pH, NO(3)(-), Fe, Mn, and Zn concentrations in the surface water of Al Asfar Lake were found to be within the international permissible limits. On the other hand, Cu and Cd concentrations exceeded the international permissible limits. The high level of some parameters of the measured heavy metals could be attributed to the contamination of Al Asfar Lake with discharge water enriched with chemical fertilizers in addition to domestic and industrial effluents.

Density Currents Dynamics over Rough Beds

Density currents are flows driven by density differences caused by suspended fine solid material, dissolved contents, temperature gradient or a combination of them. Reservoir sedimentation is often related to sediment transport by density currents. This sedimentation can block bottom outlets, reduce the capacity of reservoir and harms the dam power plants. The head is the leading edge of density currents. In this paper, the influences of artificially roughened beds on dynamics of the frontal region of density currents are investigated experimentally. Three rough beds using conic roughness elements and a smooth bed were tested. The observed trend is that as the surface roughness increases the head concentration and velocity decreases.

Effect of Rainfall and Groundwater Level on Sandy Beach Profile

In Malaysia, rainfall distribution patterns are normally influenced by seasonal wind flow patterns coupled with local topographic features. Heavy rain spells and storms during the Northeast Monsoon will affect groundwater table elevation and the beach profile. The aim of this paper is to investigate the relationship between rainfall and groundwater elevation and their effect to beach profile change. This work was undertaken at the Desaru Beach, Johor. The rainfall, groundwater table, tides and beach profiles data were measured at the site. As a result, the findings revealed that the groundwater table is affected by rainfall intensity; higher during wet season and lower during dry season. Groundwater table near the coastline is also affected by the tides. However, the data showed that there is a lag time between rising and falling of groundwater table and tides. Finally, the beach profile was found to be eroded as the groundwater elevation increased on the beach.