No abstract

The water quality of rivers in Cameron Highlands has deteriorated significantly due to land clearing for agriculture, excessive usage of pesticides and fertilizers as well as construction activities in rapidly developing urban areas. It has been investigated that non-point pollution sources (NPSs) are the main contributor of this water quality drop. NPSs are diverse and hard to identify and therefore they are difficult to estimate. Therefore, Geographical Information Systems (GIS) was used to provide an extensive approach to evaluate land use and other mapping characteristics to explain the spatial distribution of NPSs of contamination in Cameron Highlands. The method to assess pollution sources has been developed using Cameron Highlands Master Plan (2006)(2007)(2008)(2009)(2010) for integrating GIS databases, as well as pollution loads in the area of study. The results show highest annual runoff is created by forest, 3.56×10 8 m 3 /yr followed by urban development, 1.46×10 8 m 3 /yr. Furthermore, urban development causes highest BOD load (1.31×10 6 kgBOD/yr) while agricultural activities and forest contribute the highest annual loads for phosphorus (6.91×10 4 kgP/yr) and nitrogen (2.50×10 5 kgN/yr), respectively. Therefore, Non-structural management was recommended for the study area, which includes establish and provide technical advisory services unit, develop demonstration farms and provide incentives to encourage farmers in implementing sustainable agricultural management practices.

Problem statement:The aim of the study was to model the discharge, Biochemical and Chemical Oxygen Demands (BOD and COD) loads in each cross section of Bertam River in Cameron Highlands, Malaysia. Cameron Highlands form the headwater catchment for two major rivers of the lowlands; Pahang River and Perak River. On the other hand, Cameron Highlands is undergoing rapid development as a popular tourist destination and an area exploited for growing of temperature vegetables, fruits and flowers. It is also a mountainous area subjected to torrential tropical showers. The condition of Bertam River as one of the main rivers in Cameron Highlands has degraded over the years in terms of water pollution and river environment. Approach: Therefore, MIKE 11 a onedimensional hydrodynamic simulation program was utilized to model stream flow transport and water quality processing in the river system. The model was used to generate the river outflow and simulate BOD and COD concentrations in each cross section of Bertam River. Hydrodynamic Module (HD) which uses an implicit, finite difference solver was applied to calculate water level and flow for the river. Next, Rainfall-Runoff Module (RR) which is include unit hydrograph method and lumped conceptual continuous hydrological model was used to combine the meteorological data of the study area to MIKE 11 simulation system. Finally, Advection-Dispersion Module (AD) was used for transported BOD and COD concentrations calculation. Results: Water quality results show the BOD 5 varies from 1-2 mg L −1 during pre-monsoon and from 4-10 mg L −1 during post-monsoon. The COD between 39-49 mg L −1 was observed during High Water Flow (HWF). Much lower concentration was detected during Average Water Flow (AWF) which was between 10-14 mg L −1 . The comparative analysis between measured and simulated data showed that MIKE 11 is able to predict sufficiently accurate BOD and COD loads at the catchment outlet especially during AWF. Conclusion: Due to higher discharge during HWF some differences between measured and predicted values were observed. Therefore, it is suggested that for better agreement at higher discharges the hydraulic model simulation to be conducted using more measured flow data and by application of more precise differential equation such as RKQC and RK4.

Typically, palm oil mill industries use conventional anaerobic ponds for treatment of palm oil mill effluent (POME). But, this method alone cannot produce effluent discharge to an allowable limits set by the authorities. This study aimed to investigate further treatment of anaerobically digested POME (COD = 682±14 mgL-1, TSS = 29±7 mgL-1 and turbidity = 106±3 NTU) by coagulation-flocculation process. Alum, an industrial-accepted coagulant and OC 100 and PC 100W as two industrial-based polymeric flocculants were used in coagulation-flocculation process. Results indicate coagulation process in its optimum conditions (pH = 6, alum dosage = 1800 mgL-1, rapid mixing = 5 min, and slow mixing = 20 min) reduces the COD, TSS and turbidity by 59%, 80% and 86%, respectively. Flocculants OC 100 and PC 100W caused further reduction of TSS (85–88%) and turbidity (97–98%). By application of post treatment, the POME characteristics reached to an acceptable discharge level enforced by Malaysian department of environment (DOE).