1. UKM Learning and Research Repository
2. PHD Thesis / Tesis PHD
3. Faculty of Science and Technology / Fakulti Sains dan Teknologi

Title:	Water quality and sediment analysis of Langat and Semenyih rivers, Selangor, Malaysia
Authors:	Hana Saeed Ahmed Al-Ganahi (P39802)
Supervisor:	Mohamad Shuhaimi Othman, Assoc. Prof. Dr.
Keywords:	Water quality Sediment Langat River Semenyih River Contamination Dissertations, Academic -- Malaysia
Issue Date:	Jun-2016
Description:	In this study, spatial and temporal water quality variations in the Langat and Semenyih rivers were evaluated to estimate variations in the surface water quality of the two rivers with regard to changes in sampling events (annual changes) as well as the locations of sampling sites (land-use map, 2008–2013) using national water quality standards for Malaysia (NWQS). Hierarchical cluster analysis (HCA), principal component analysis (PCA), water quality index (WQI) and risk assessment code (RAC) techniques were used to investigate the spatial variations in surface river water quality and sediment analysis. Each river was divided into 10 sampling stations and the sampling was divided into three distinct periods every three months (August 2008 to March 2009) to assess the pollution status. Water quality (temperature, DO, pH, turbidity, conductivity, BOD5, COD, TSS, PO4, SO4, NO3, NO2, NH3-N and water hardness), heavy metals and sediment (pH, organic matter (OM), particle size (PS) and RAC) parameters were measured at all sampling stations within all the sampling periods. The results of the multivariate statistics (HCA and PCA) and WQI were discussed in relation to similarities between water quality characteristics and land-use activities. The results of the water quality analysis showed that the upstream sections had excellent water quality, which were identified as class I, while at the fourth sampling station onwards, water quality declined into class III. The water quality during a period with no rain (SP2), however, indicated the presence of many sources of pollution. During rainy periods (SP1 and SP3) NH3-N and PO4 concentrations were higher than the SP2 period. Therefore these shows the studied rivers were contaminated by NH3-N and PO4. The heavy metals concentrations were not significantly different, even under different weather conditions. All heavy metals concentrations were below NWQS. The order of heavy metal concentrations in the Langat and Semenyih rivers' water samples was Fe>Mn>Zn>Ni>Cu>Pb and Fe>Mn>Zn>Cu>Ni>Pb respectively. According to RAC criteria, the mean percentages of metal in the rivers' sediment were considered to be within the medium- to high-risk category, and could easily enter the food chain. Exceptions were observed for both upstream sites (sampling stations 1 and 2) where the metal concentration was very low. It was found that the levels of the anthropogenic portions of the investigated metals had decreased in the order Mn>Zn>Cu>Ni>Pb>Fe and Mn> Pb>Zn>Cu>Ni>Fe for the Langat and Semenyih rivers respectively. The HCA classified the 10 sampling stations from the Langat River into four cluster groups, and two cluster groups for the Semenyih River, based on similarities of water quality features, whereas the total of HCA clusters exact equal to number major land-use activities. The PCA analyses showed that urban land use and other nonpoint sources such as range land-use together explain the three main factors that contribute to contamination in the Langat River: urban, agricultural, and rural; while only two factors, rural and agricultural, were found to have contributed to the contamination of the Semenyih River. The WQI indicted both rivers were at a polluted level, especially based on BOD5, NH3 and TSS. Overall, results of the study demonstrated that the water quality characteristics of the Langat and Semenyih rivers were highly dependent on the land-use composition of the rivers.,Certification of Master's/Doctoral Thesis" is not available
Pages:	222
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.