Evaluation of heavy metal contamination in groundwater samples from Kapas Island,Terengganu, Malaysia   总被引：1，自引：0，他引：1  

Noorain Mohd Isa  Ahmad Zaharin Aris  Wan Ying Lim  Wan Nor Azmin Wan Sulaiman  Sarva Mangala Praveena 《Arabian Journal of Geosciences》2014,7(3):1087-1100

An attempt has been made to delineate the hydrochemistry for a small island based on the major ions and heavy metal concentrations. In this investigation, six sampling campaigns were conducted to measure the concentrations of major ions (Ca, Mg, Na, K, HCO₃, Cl, and SO₄) and heavy metals (Zn, Cr, Pb, Mn, As, and Cu) in groundwater samples collected from seven sampling stations (boreholes) located on Kapas Island, Terengganu, Malaysia. The distribution of major ions is illustrated by a piper plot where Ca–HCO₃ is the dominant type. In addition, the concentrations of heavy metals demonstrate that Mn shows as being the highest concentrated heavy metal in the groundwater sampled in the sampling campaigns; the average Mn content in groundwater sampled was 54.05 μg/L. However, a comparison of the heavy metal (Mn, Cr, Zn, As, Pb, and Cu) concentrations in groundwater samples with the Drinking Water Quality Standard prescribed by World Health Organization reveals that none of these heavy metals exceeded the recommended threshold limits. The principal component analyses (PCA) extracted four components that control the groundwater chemistry. Components 1 and 2 from the PCA analyses extracted approximately 52.11 % of the total variance, which represent the heavy metals (As and Mn) and physical parameters (pH, redox potential, electrical conductivity, temperature, and total dissolved solids). Based on the output of the PHREEQC hydrogeochemical software, several species of heavy metals exist, in which the dominant species found are Mn²⁺, PbCO₃, Cu(OH)₂, and Zn⁺.  相似文献   

Wind energy potential assessment using Weibull distribution with various numerical estimation methods: a case study in Mersing and Port Dickson,Malaysia     

Safari  Muhammad Aslam Mohd  Masseran  Nurulkamal  Majid  Muhammad Hilmi Abdul 《Theoretical and Applied Climatology》2022,148(3-4):1085-1110

Theoretical and Applied Climatology - In this study, the Weibull distribution with various numerical estimation methods is utilized for the assessment of wind energy potential in Mersing and Port...  相似文献   

A knowledge-driven GIS modeling technique for groundwater potential mapping at the Upper Langat Basin, Malaysia   总被引：3，自引：1，他引：2  

Mohamad Abd Manap  Wan Nor Azmin Sulaiman  Mohammad Firuz Ramli  Biswajeet Pradhan  Noraini Surip 《Arabian Journal of Geosciences》2013,6(5):1621-1637

The aim of this paper is to use a knowledge-driven expert-based geographical information system (GIS) model coupling with remote-sensing-derived parameters for groundwater potential mapping in an area of the Upper Langat Basin, Malaysia. In this study, nine groundwater storage controlling parameters that affect groundwater occurrences are derived from remotely sensed imagery, available maps, and associated databases. Those parameters are: lithology, slope, lineament, land use, soil, rainfall, drainage density, elevation, and geomorphology. Then the parameter layers were integrated and modeled using a knowledge-driven GIS of weighted linear combination. The weightage and score for each parameter and their classes are based on the Malaysian groundwater expert opinion survey. The predicted groundwater potential map was classified into four distinct zones based on the classification scheme designed by Department of Minerals and Geoscience Malaysia (JMG). The results showed that about 17% of the study area falls under low-potential zone, with 66% on moderate-potential zone, 15% with high-potential zone, and only 0.45% falls under very-high-potential zone. The results obtained in this study were validated with the groundwater borehole wells data compiled by the JMG and showed 76% of prediction accuracy. In addition statistical analysis indicated that hard rock dominant of the study area is controlled by secondary porosity such as distance from lineament and density of lineament. There are high correlations between area percentage of predicted groundwater potential zones and groundwater well yield. Results obtained from this study can be useful for future planning of groundwater exploration, planning and development by related agencies in Malaysia which provide a rapid method and reduce cost as well as less time consuming. The results may be also transferable to other areas of similar hydrological characteristics.  相似文献   

Land subsidence and declining water resources in Quetta Valley, Pakistan   总被引：1，自引：0，他引：1  

Abdul S. Khan  Shuhab D. Khan  Din M. Kakar 《Environmental Earth Sciences》2013,70(6):2719-2727

Extensive groundwater withdrawals in urban areas may cause water shortages, land subsidence, and water quality problems. The Quetta Valley is the largest population center in Balochistan province in western Pakistan. This area is arid and groundwater is the main water source for domestic and agricultural use. This work presents global positioning system (GPS) data and assessment of spatial and temporal variations in water levels. GPS data from two stations from mid-2006 to the beginning of 2009 show subsidence rate of 10 cm\year. Nine satellite images from 1975 to 2009 were classified and processed to quantify land cover and land use changes, which highlight an increase in agricultural areas in the central region of the Quetta Valley, as well as reduced vegetation on mountains. These data correspond to gradual temporal changes in water volumes in streams and lakes. Average temperatures have also increased and mean precipitation has decreased during this period. However, the greatest change in this area has been in population growth, which rose from 260,000 in 1975 to 1.2 million in 2010, mainly due to migration of refugees from war-torn neighboring Afghanistan. The Quetta Valley provides a good example for studying the impact of urbanization on water resources.  相似文献   

Interacting modified holographic dark energy in Kaluza-Klein universe     

M. Sharif  Abdul Jawad 《Astrophysics and Space Science》2012,337(2):789-794

The interaction of modified holographic dark energy and dark matter with varying G in flat Kaluza Klein universe is considered. Further, we take infrared cutoff scale L as future event horizon. In this scenario, equations of state parameter as well as evolution are explored. We also check the validity of the generalized second law of thermodynamics. It is interesting to mention here that our results show consistency with the present observations.  相似文献   

Computerised development control and approval system for City Hall of Kuala Lumpur     

Ahris Yaakup  Yazid Bakar  Mohd Kadir  Susilawati Sulaiman 《地球空间信息科学学报》2013,16(1):39-49

This paper will discuss the computerised development control and approval system being developed for the Planning and Development Control Department. City Hall of Kuala Lumpur, with stress on the GIS architecture developed within the system. The prospects and challenges towards implementation of the system are also discussed.  相似文献   

Removal of Hydrogen Sulfide by Physico‐Biological Filter Using Mixed Rice Husk Silica and Dried Activated Sludge     

Seyed Mahmoud Mehdinia  Puziah Abdul Latif  Hassan Taghipour 《洁净——土壤、空气、水》2013,41(10):949-954

This study investigated the effectiveness of a new packing material, namely mixed rice husk silica with dried activated sludge for removing H₂S. Dried sewage sludge was collected from Putrajaya sewage treatment plant in Malaysia. Rice husk silica was prepared at temperature of 800°C, after acid leaching and mixed with dried sewage sludge to be utilized in a polyvinyl chloride filter. The system was operated under variable conditions of two parameters, different inlet gas concentration and different inlet flow rate. H₂S was passed through the filter with one liter of the packing material. More than 99.96% removal efficiency (RE) with empty bed residence time (EBRT) of 90–45 s and 300 ppm inlet concentration was observed. However, the RE decreased to 96.87% with the EBRT of 30 s. The maximum elimination capacity (EC) of 52.32 g/m³/h was obtained with the RE of 96.87% and H₂S mass loading rate of 54 g/m³/h, while at the RE of 99.96%, maximum EC was 26.99 g/m³/h with the H₂S mass‐loading rate of 27 g/m³/h. A strong significant correlation between increasing of H₂S mass loading rate and pressure drop was also detected (p < 0.01). Maximum pressure drop was 3.0 mm H₂O after 53 days of operating time, the EBRT of 30 s, and 54 g/m³/h of H₂S loading rate. These observations suggest that the mixture of rice husk silica with dried activated sludge is a suitable physico‐biological filter for H₂S removal.  相似文献   

Effect of Ozone and Ozone/Fenton in the Advanced Oxidation Process on Biodegradable Characteristics of Semi‐aerobic Stabilized Leachate     

Salem S. Abu Amr  Hamidi Abdul Aziz  Mohd Nordin Adlan  Shuokr Qarani Aziz 《洁净——土壤、空气、水》2013,41(2):148-152

This study investigated the effects of O₃ and O₃/H₂O₂/Fe²⁺ in the advanced oxidation processes (AOPs) on the biodegradable and soluble characteristics of semi‐aerobic stabilized solid waste leachate. The biodegradability (BOD₅/chemical oxygen demand, COD) ratio improved from 0.034 to 0.05 and 0.1 following O₃ and O₃/H₂O₂/Fe²⁺, respectively. Fractions of biodegradable COD_(bi) (24%), non‐biodegradable COD_(ubi) (76%), soluble COD_(s) (59%), biodegradable soluble COD_(bsi) (38%), non‐biodegradable soluble COD_(ubsi) (62%), and particulate COD (PCOD) (41%) in stabilized leachate were also investigated. The fraction of COD_(bi) increased to 28 and 36% after applying O₃ and O₃/AOPs, respectively. COD_(S) increased to 59% after O₃ and to 72% after O₃/AOPs, whereas COD_(bsi) increased to 38 and 51% after O₃ and O₃/AOPs, respectively. The removal efficiency of COD_(S) was obtained at 5% after O₃ alone and improved to 51% following ozone‐based AOPs, whereas the removal efficiency of PCOD improved from 25% after O₃ to 71% after ozone‐based AOPs.  相似文献   

A context-aware personalized travel recommendation system based on geotagged social media data mining   总被引：1，自引：0，他引：1  

Abdul Majid  Gencai Chen  Hamid Turab Mirza  Ibrar Hussain  John Woodward 《International journal of geographical information science》2013,27(4):662-684

The proliferation of digital cameras and the growing practice of online photo sharing using social media sites such as Flickr have resulted in huge volumes of geotagged photos available on the Web. Based on users' traveling preferences elicited from their travel experiences exposed on social media sites by sharing geotagged photos, we propose a new method for recommending tourist locations that are relevant to users (i.e., personalization) in the given context (i.e., context awareness). We obtain user-specific travel preferences from his/her travel history in one city and use these to recommend tourist locations in another city. Our technique is illustrated on a sample of publicly available Flickr dataset containing photos taken in various cities of China. Results show that our context-aware personalized method is able to predict tourists' preferences in a new or unknown city more precisely and generate better recommendations compared to other state-of-the-art landmark recommendation methods.  相似文献   

A three-step strategy for generalization of 3D building models based on CityGML specifications     

Siddique Ullah Baig  Alias Abdul Rahman 《GeoJournal》2013,78(6):1013-1020

3D building models of the world exhibit multi-scale properties. Different level-of-details (LoDs) are important for different applications. Therefore, generation of multi-scale representation of 3D building models to fulfill the demands of these applications is a generalization problem. In order to generalize 3D buildings, different pieces of information need to be preserved or removed to restrict the amount of data represented on a certain LoD. In this work, a three-step strategy based on simplification, aggregation and reconstruction of generalized buildings represented in City Geography Markup Language (CityGML) is proposed. The minimum length of edges (threshold value) for removal of amount of data is restricted to generalization specifications of CityGML characterized by differing accuracies and minimal dimensions of objects for each LoD. The main part of this paper is simplification of ground plans. For this purpose, a new approach is proposed to restrict number of edges, curves, and corners of ground plan of 3D building model on a certain LoD. Algorithms for simplification with the aim to derive LoD1 from exterior shells of buildings at LoD3 are implemented and tested on a number of buildings of Putrajaya city. The experiments showed that length of edge as threshold value is directly proportional to the size of generalized models.  相似文献