No abstract

Bioaccumulation of toxic metals in fish causes serious threats to human when they are consumed. Thus, the detection of toxic element concentration levels in aquatic component is important. The accumulation of some heavy metals such as Cd, Cu, Fe, Mn, Pb and (ICP-MS)

Many new agricultural activities resulted in severe soil erosion across the Cameron Highlands’ land surface. Therefore, this study determines the cover (C) and land management (P) factors of the USLE for predicting soil loss risk in Cameron Highlands using a Geographic Information System (GIS). For this study, data from the Department of Agriculture Malaysia (DOAM) and the Department of Town and Country Planning Malaysia (PLANMalaysia) were used to generate several C&P factors in the Cameron Highlands. Data from both agencies have resulted in C factors with 0.01 to 1.00 and P factors with 0.30 to 0.49. Due to the cover and land management factor varies depending on the data collected by the various agencies, this study used the two data sets to come up with a C&P factor that accurately reflected both agricultural and urban growth effects. RKLS factors of USLE were obtained from the DOAM with values R (2375–2875), K (0.005), LS (2.5–25), respectively. The Cameron Highlands’ soil loss risk with these new C&P values resulted in a soil loss of 6.72 per cent (4547.22 hectares) from high to critical, with a percentage difference range of −0.77 to +3.37 under both agencies, respectively.

In this work, an atmospheric water generator (AWG) system called the medium-scale AWG (MSAWG) was designed, fabricated, and tested in Universiti Sains Malaysia (USM) under the outdoor tropical climate conditions of Malaysia to investigate the amount of fresh water production in successive periods of 24 h. The MSAWG consisted of 18 thermoelectric cooler (TEC) units, 18 internal finned heat sinks, 18 external finned heat sinks, 18 direct current (DC) cooling fans, an air-conditioner mesh air filter, and an axial ventilation fan. It was found from the results that the hourly values of water production of MSAWG were proportional to the hourly rates of relative humidity, but they were inversely affected by the corresponding hourly values of the ambient temperature. Night-time and early morning were the most effective times to produce the highest amount of fresh water from Malaysia’s atmosphere using MSAWG, as the increase in the rates of relative humidity and the decrease in the values of ambient temperature occurred over these periods. Based on the varied hourly rates of relative humidity with the ranges between the minimum rate of 55% and maximum rate of 85%, an equation of Y = 0.2285X + 36.675 with R2 of 0.9404 was achieved from the 48 h experimental work to estimate the water production of MSAWG in Malaysia, where Y and X were indicated as the rate of relative humidity and the value of water production, respectively, in this equation. In conclusion, the MSAWG produced a consecutive cumulative water volume of 3.432 and 6.997 L experimentally in the periods of 24 and 48 h, respectively. The estimated cost per liter for MSAWG was USD 0.466. Some water quality parameters of the fresh water produced by MSAWG were analysed in the laboratory, which showed that they met the World Health Organization (WHO) drinking water standards. Therefore, MSAWG can be employed as a sustainable alternative to generate annual daily fresh water from Malaysia’s tropical atmosphere and aid in mitigating the problem of unpredicted water shortage in the country.

Treating urban grey water with physical, chemical, and biological treatment techniques and reusing it as a sustainable non-potable water source has received much attention recently, yet there is a lack of studies regarding it. In this work, a typical slum nearby an urban household area in Malaysia was selected as a source of contaminated grey water which is located on the opposite side of a building site (100°29′ E and 5°7′ N) located in an urban area in a city in the Perak state, namely Parit Buntar, where the total urban grey water was being accumulated. Poor sanitation of that slum was seen to pose various health risks to the public, and hence, the importance of treating its grey water was perceived. Thus, this study was conducted to evaluate the performance of a low-cost double slope passive solar still by treating the grey water from the aforementioned slum, as well as to analyze the quality, quantity, and cost per liter of the produced water. Grey water was collected and filled in the solar still basin at s depth of 1 cm. The cover and basin of the solar still were made from transparent polythene film and black-painted stainless steel trough, respectively, while the frame was made from polyvinyl chloride (PVC), and the solar still was named PSSG1 abbreviated. PSSG1 was exposed to Malaysia’s climate conditions for several days from 8.00 a.m. to 6.00 p.m. at Universiti Sains Malaysia (USM), which was able to produce the maximum amount of water up to 4.11 L/m2·d with the cost per liter/m2 of only USD 0.0082. Water quality parameters tested showed that water produced from PSSG1 met the standards of the restricted and unrestricted reusable non-potable grey water, the World Health Organization (WHO), and the Malaysian class I drinking water standards. It was also found that the PSSG1 with higher average daily basin water temperature produced water with higher quality for the reuse applications and yielded healthier water compared to the water produced by some reported previous grey water treatment techniques. Therefore, the cost-effective PSSG1 can be used as a daily practical alternative for treating low-strength grey water collected from various urban household areas in Malaysia in order to assist pollutants removal from the drained urban grey waters.