Zulhilmi Ismail

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.

Wasted cockle shell (Anadara granosa) as a natural adsorbent for treating polluted river water in the fabricated column model (FCM)

AbstractThe potential use of crushed cockle shells (Anadara granosa) for treating polluted river water in the fabricated column model was investigated along with the determination of the optimum amount of A. granosa used in the fabricated column model based on the results obtained from the series of jar test experiments performed during the study. The result shows that the crushed cockle shell could reduce chemical oxygen demand with the adsorption capacity of 5.3191 mg g−1. Moreover, based on adsorption isotherm, it is shown that the adsorption data best fitted for Freundlich (R2 = 0.9798) when compared to Langmuir isotherm (R2 = 0.5737). The breakthrough curves plotted based on the data obtained from fabricated column model experiment indicates that the exhaustion time of crushed cockle shell was on the third day. The linearization of breakthrough curves based on Thomas model, Yoon–Nelson model, and Adam–Bohart model, shows that the curves best fitted with Adam–Bohart model, since the value of R2 was hi...

Flood Damage Assessment: A Review of Flood Stage–Damage Function Curve

Nowadays, flood control has been replaced by flood management concept in terms of living with flood, making benefit of it, and minimizing its losses. The success in flood management in any region depends on the evaluation of different types of flood losses. For the assessment of flood damages, this requires the use of stage–damage functions for different categories of land use. A review is presented of the methods used to construct stage–damage function curves for residential, commercial, agricultural, and industrial category. Two main approaches in constructing stage–damage functions are empirical approach, which is based on damage data of past floods, and synthetic approach, which uses damage data collected by interview survey or questionnaire. For a developing country like Malaysia which has limited history and actual flood damage data, the synthetic method is the preferred approach in constructing stage–damage function curve.

Amphibious urbanization as a sustainable flood mitigation strategy in South-East Asia

Appling amphibious urbanization is a new smart and sustainable flood mitigation strategy for floodplain area in South-East Asia. The objective of this study is to evaluate the technological and environmental aspects of the amphibious house as a sustainable flood mitigation strategy in South-East Asia. The technological and environmental aspects are investigated under sustainability. The point load test and drag force estimation and interviews are conducted. Amphibious urbanization is completely aligned with the technological aspects of a safe living conditions during flood rush. This system identified as one of the green and most sustainable new strategies in South-East Asia.

Drag coefficient for amphibious house

Abstract Recently, flooding has become a serious issue and disaster in Malaysia. Therefore, it is crucial to search for a more effective flood mitigation approach in Malaysia. Amphibious house system is a new sustainable and flexible flood mitigation measure within a floating urbanization environment. Amphibious house has been designed based on buoyancy terminology by using precast and fast formulatable concrete components such as concrete pontoons. These pontoons are made of green lightweight concrete and analysed for buoyancy and stability against vertical and horizontal loads. This study aims to identify the precise force calculation from floods to amphibious houses as a new flood mitigation system. The objective of this study is to develop a new equation for calculating the drag coefficient for the amphibious house. A new experimental method is used to calculate drag force on the amphibious house in 1/25 scaled-down floodplain model. As a result, the new equation is developed for the drag coefficient. The sensitivity analysis shows the accuracy of this research.

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.