Rapid urbanisation has caused an increased in peak discharge that conventional drainage systems cannot adequately handle. Low Impact Development (LID) practices are becoming a new approach in helping to better mimic the pre-development discharges. This study aims to evaluate the effectiveness of LID and Best Management Practices (BMP) under different rainfall conditions. Vegetative swale and detention pond were selected to represent LID and BMP. Simulations of four main scenarios namely, base case, LID, BMP, and combined LID-BMP were performed using Stormwater Management Model (SWMM). Results show that among the scenarios simulated, the combined LID-BMP is most effective with average peak flow reduction of 54%. This is followed by BMP that achieved 37% in average peak flow reduction as compared to 27% peak flow reduction by LID. The findings indicate the need for integrated strategy when dealing with stormwater management measures.
Reservoir was the main sources in order to get basic needs in daily life but due to human activities the quality of water environment affected. A reservoir ordinarily formed by the construction of dam to store water. The most commonly purposed of this reservoir is to provide flood control, supply water for domestic purpose and to generate hydroelectric power. Reservoirs provide the most effective control for unexpected floods when reservoir waters levels are low, so that excess runoff can be storage. However, trapping sediments have been identify due to some of the environmental damages. Reservoir sedimentation is a very serious problem that will cause capacity reduction and water quality deterioration. This paper provides a framework to understand deeply the principles of siphon and to improve the design of the siphon to remove the sediment in reservoir.
Water treatment sludge (WTS) has been a major global problem and dealing with it remains a challenge for scientists and engineers. WTS is expected to increase annually parallel to the continuous increase in population [1]. Every year, 2 million tons of WTS is produced by water operators in Malaysia to cope with the increase population number of 16, 800/year [2], [3]. WTS can be highly toxic for environment and human health. WTS has a tendency to cause soil pollution when it disposed on the land or even from acidic rain. The exposure tends to cause the breaking down soils and releasing heavy metals into streams, lakes, rivers and groundwater [4]. Metals in untreated WTS tends to accumulate although the metals are usually found at low level of concentration. Due to the hazardous effects that can cause to environmental and human health problems prior to land disposal, issues of WTS needs to be treated before dump should be considered. One of sludge treatment technique is Solidification/Stabilisation (S/S) technique. The application of S/S technique to treat WTS is somehow limited as WTS is always considered to be non-toxic. Thus, incineration and landfilling are alternative sludge treatment practiced till today [5]. S/S technique is simple in operation and should be implemented Abstract: Waste Paper Sludge Ash (WPSA) was used as stabilizer binder to treat water treatment sludge (WTS). This study was conducted to treat WTS by using WPSA in Solidification/Stabilisation (S/S) technique. WPSA was utilized at 10%, 20%, 30%, 40% and 50% to treat 200g WTS at binder-to-sludge (B/Sd) ratio 1:1. The control sample was 100% Ordinary Portland Cement (OPC). The compressive strength and leaching test on WTS treated with WPSA at specified percentage were performed. The compressive strength was conducted on sample cured at age 1, 3, 7 and 28 days. The leaching test was conducted only on sample cured at age 28 days. The minimum target compressive strength was 0.34 MPa as accordance to USEPA. The maximum metals acceptance criteria as stipulated by Kualiti Alam were 1.0, 5.0, 100.0, 100.0 and 5.0 mg/L for cadmium (Cd), lead (Pb), nickel (Ni), copper (Cu) and chromium (Cr) respectively. Results showed that the compressive strength decreases with increasing WPSA content but exceeded the minimum target strength. The compressive strength increases with respect to curing days. The optimum content of WPSA to treat WTS was 50% (W5). The compressive strength of W5 with high WPSA content was the first exceeded the minimum compressive strength. The concentration of metals decreases with respect to percentage of WPSA added.
The purpose of this study is to assess patterns of extreme rainfall and this study focused on the changes between two phases for extreme rainfall, for the period of 1971 to 2011 and from 1995 to 2011 in Kuala Lumpur and Selangor. The generalised extreme value distribution appears to outperform other distribution functions such as two-parameter Gumbel and lognormal and the three-parameter generalized extreme value (GEV), lognormal (LN3) and log Pearson (LP3) in modeling the one-hour annual maximum rainfall series from 14 stations. The estimated return period of 20, 50, 100-year for each stations based on the best fitting model for the periods of entire record data and from 1995-2011 have been computed. More than 70% of estimated quantiles using rainfall data from 1995-2011 are higher compared to estimation using the entire recorded data.
The aim of this paper is to investigate the performance response of a set of coir fibre modified asphalt samples subjected different ageing conditions and containing three different fibre contents. The laboratory experimental programs are indirect tensile test at 25°C and repeated load axial test at 40°C. The results showed that the fibres improved the mixture’s performance. The main findings obtained at 25°C for short and long-term ageing reveal that low fibre content at around 0.3% per aggregate weight display a stiffness modulus up to 14% higher than that of unmodified mixtures, hence showing that fibres may improve the bearing capacity and rut-resistance of asphalt mixtures. Conversely, as the amount of fibre increases to 0.5% and 0.7%, the stiffness decreases to the point of becoming unacceptably low, almost 80% lower than unmodified mixes stiffness. However the data also reveal that high fibre contents at 0.5% and above completely neutralize the impact of ageing on the mixture, indicating that fibre-modified mixtures would yield longer lives.
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