Faradiella Mohd Kusin

Hybrid off-river augmentation system as an alternative raw water resource: the hydrogeochemistry of abandoned mining ponds

The use of water from abandoned mining ponds under a hybrid off-river augmentation system (HORAS) has been initiated as an alternative water resource for raw water. However, it raises the questions over the safety of the use of such waters. In this study, the hydrogeochemical analysis of the waters is presented to assess the degree to which the water has been contaminated. Comparisons were made between sampling sites, i.e. abandoned mining ponds, active sand mining ponds and the receiving streams within Bestari Jaya, Selangor River basin. The aqueous geochemistry analysis showed different hydrochemical signatures of major elements between sites, indicating different sources of minerals in the water. Discharges from the sand mining ponds were found to contain elevated availability of dissolved concentrations of iron, manganese, lead, copper and zinc, among others. However, the quality of the water (from the main river) that is supplied for potable water consumption is at a satisfactory level despite being partly sourced from the abandoned mining ponds. In fact, all the metal concentrations detected were well below the Malaysia Ministry of Health guideline limits for untreated raw water. In addition, the results of the geochemical index analysis (i.e. geoaccumulation index, enrichment factor and modified contamination factor) showed that the rivers and abandoned mining ponds were generally unpolluted with respect to the metals found in sediments.

The occurrence and potential ecological risk assessment of bauxite mine-impacted water and sediments in Kuantan, Pahang,Malaysia

Recent bauxite mining activities in the vicinity of Kuantan, Pahang, have been associated with apparent environmental quality degradation and have raised environmental concerns among the public. This study was carried out to evaluate the overall ecological impacts on water and sediment quality from the bauxite mining activities. Water and sediment samples were collected at seven sampling locations within the bauxite mining areas between June and December 2015. The water samples were analyzed for water quality index (WQI) and distribution of major and trace element geochemistry. Sediment samples were evaluated based on geochemical indices, i.e., the enrichment factor (EF) and geoaccumulation index (Igeo). Potential ecological risk index was estimated to assess the degree to which sediments of the mine-impacted areas have been contaminated with heavy metals. The results showed that WQIs of some locations were classified as slightly polluted and contained metal contents exceeding the recommended guideline values. The EFs indicated minimal to moderate enrichment of metals (Pb, Cu, Zn, Mn, As, Cd, Cr, Ni, Co, and Sr) in the sediments. Igeo showed slightly to partially polluted sediments with respect to As at some locations. The potential ecological risk index (RI) showed that As posed the highest potential ecological risk with RI of 52.35–60.92 at two locations, while other locations indicated low risk. The findings from this study have demonstrated the impact of recent bauxite mining activities, which might be of importance to the local communities and relevant authorities to initiate immediate rehabilitation phase of the impacted area.

Integrated River Basin Management: incorporating the use of abandoned mining pool and implication on water quality status

AbstractExploring alternative water resource has been an option in an Integrated River Basin Management approach for Selangor River Basin, Malaysia. This includes the use of abandoned mining pool water as additional raw water resource to downstream water treatment plants. Monitoring of water quality along Selangor River was performed at selected locations within the river basin including active (sand mining) and abandoned mining pools to evaluate on current water quality status of the river for raw water supply. Measured variables were compared with the recommended acceptable value by the Ministry of Health (MOH) for guideline compliance. Generally, the abandoned mining pools were classified as Class II according to Water Quality Index sufficient to be used as alternative water resource in terms of water quality and have metal contents below the recommended acceptable values. The water intake point of the water treatment plant downstream the river basin indicated satisfactory water quality level and in co...

Passive bioremediation technology incorporating lignocellulosic spent mushroom compost and limestone for metal- and sulfate-rich acid mine drainage

ABSTRACT Passive bioremediation of metal- and sulfate-containing acid mine drainage (AMD) has been investigated in a batch study. Multiple substrates were used in the AMD remediation using spent mushroom compost (SMC), limestone, activated sludge (AS), and woodchips (WC) under anoxic conditions suitable for bacterial sulfate reduction (BSR). Limestones used were of crushed limestone (CLS) and uncrushed limestone, provided at two different ratios in mixed substrates treatment and varied by the proportion of SMC and limestone. The SMC greatly assisted the removals of sulfate and metals and also acted as an essential carbon source for BSR. The mixed substrate composed of 40% CLS, 30% SMC, 20% AS, and 10% WC was found to be effective for metal removal. Mn, Cu, Pb, and Zn were greatly removed (89–100%) in the mixed substrates treatment, while Fe was only removed at 65%. Mn was found to be removed at a greatly higher rate than Fe, suggesting important Mn adsorption onto organic materials, that is, greater sorption affinity to the SMC. Complementary with multiple treatment media was the main mechanism assisting the AMD treatment through microbial metal reduction reactions.

THE IMPACT OF NITROGEN FERTILIZER USE ON GREENHOUSE GAS EMISSIONS IN AN OIL PALM PLANTATION ASSOCIATED WITH LAND USE CHANGE

The emissions of greenhouse gases (GHGs) in an oil palm plantation associated with land use change have been evaluated on a site-specific basis. Nitrous oxide (N ₂ O) emissions from the application of nitrogen fertilizers during the growth stages of the palm oil were analyzed for palms of different ages within the plantation. The N ₂ O release ranges between 19.11-22.17 kg of N 2 O-N/ha, resulting in the emission of 1052.26-1209.51 kg of CO 2 -eq/ha. However, there is no clear relationship between the emissions of N 2 O or CO 2 -eq and the age of the oil palms. On the other hand, the impact from land use change for the development of the site was also evaluated by assessing the emissions from carbon stock changes within the plantation. The transformation of a rubber estate into an oil palm plantation loses the soil carbon content (i.e., release of carbon emissions). However, this phenomenon has been anticipated in literature. Overall, fertilizer-related emissions and fuel emissions during the growth stages contribute to about 79 and 21%, respectively, of the total GHG emissions from the plantation . Therefore, it is likely that the application of nitrogen fertilizer may increase the existing carbon emission from the conversion of rubber to oil palm plantation, but the values are within the estimated for a Malaysian oil palm plantation.

Phytoremediation Potential of Vetiver Grass ( Vetiveria zizanioides ) for Treatment of Metal-Contaminated Water

Phytoremediation using vetiver grass (Vetiveria zizanioides) has been regarded as an effective technique for removing contaminants in polluted water. This study was conducted to assess the removal efficiency of heavy metals (Cu, Fe, Mn, Pb, Zn) using vetiver grass (VG) at different root lengths and densities and to determine metals uptake rate by plant parts (root and shoot) between treatments (low and high concentration). Removal efficiency for heavy metals in water by VG is ranked in the order of Fe>Pb>Cu>Mn>Zn. Results showed that VG was effective in removing all the heavy metals, but removals greatly depend on root length, plant density and metal concentration. Longer root length and higher density showed greater removals of heavy metals due to increased surface area for metal absorption by plant roots. Results also demonstrated significant difference of heavy metals uptake in plant parts at different concentrations indicating that root has high tolerance towards elevated concentration of heavy metals. However, the effects were less significant in plant shoot suggesting that metals uptake were generally higher in root than in shoot. The findings have shown potential of VG in phytoremediation for heavy metals removal in water thus providing significant implication for treatment of metal-contaminated water.

Nitrous oxide emission from nitrogen fertiliser application in oil palm plantation of different stages

The release of nitrous oxide (N2O) from agricultural activities contributes to the increase of greenhouse gases in the atmosphere. In this study, the amount of nitrogen fertiliser used in an oil palm plantation of different stages (immature and mature) was estimated. Data of fertilising scheme at the oil palm plantation for oil palms varying in age (planted between 1986 and 2009) was used. Estimation of nitrous oxide emissions and the resulting CO2-equivalent (CO2-eq) emissions were calculated for each category of the oil palm. The amounts of N-fertiliser applied were between 102137 kg N/ha. The resulting N2O emissions were between 19.07-22.10 kg N2O-N/ha, which corresponds to CO2-eq of between 2223.53-2700.42 kg CO2-eq/ha. It was also estimated that about 29.87-34.63 g CO2 were emitted per MJ crop. The N2O emission per ha oil palm was found to decrease from immature stage until maturely-developed stage spanning 20 years. The CO2-eq amount decreased only after ten years of oil palm development. The results were also compared for synthetic nitrogen fertiliser-induced emissions within tropical regions.

Performance assessment of centrifuge dewatering unit using multivariate statistical approach: a case study of a centralized sludge treatment facility (CSTF) in Malacca, Malaysia

AbstractThe performance of the centrifuge dewatering unit in Sungai Udang centralized sludge treatment facility has been studied using multivariate statistical approach. The relationships between bio-solids production and 14 parameters were analyzed using principle component analysis (PCA) and multiple linear regression (MLR) analysis. PCA was used to simplify the complexity among variables affecting the production of bio-solids in the treatment facility. All varimax factor (VF) values obtained from the PCA were used as independent variables in MLR analysis. It was found that VF1 (wet sludge and mixed liquor suspended solids) and VF4 (polymer dosage) had significant linear relationships with bio-solids production, which accounted for 74.32% of variations in the bio-solids production. This approach could be used to precisely estimate the amount of sludge produced by the centrifuge dewatering unit and for better evaluation of system performance that meets the design criteria and future requirements for slud...

Anoxic Limestone Drain for Treatment of Highly Acidic Water

Limestone has been widely used in the treatment of acidic water due to its capability of neutralizing acid and removing metals in water. This study investigated the efficiency of limestone treatment in treating acidic water in anoxic limestone drain at a laboratory scale. The anoxic limestone drain was basically designed to enhance limestone dissolution and alkalinity generation thus minimizing the potential of armouring, which may decrease the rate of acid neutralization. Actual raw water samples from two different locations within Sg. Bekok catchment which were highly acidic with low pH values were used in the experiment treated by 30 mm diameter of 112 kg of limestone. The conditions under which the pH increases, acidity decreases, alkalinity produced and metals were removed in the anoxic limestone drain have been determined. pH was significantly increased from initially 3.27–4.09 to 6.49–6.67 after flowing through the anoxic drain in 10 min of contact with the limestone. Acidity was reduced from 73–99 mg/L as CaCO3 to 17–19 mg/L as CaCO3 as pH were raised to reach near neutral levels. Iron and aluminium were also being removed in the anoxic limestone drain.

Role of multiple substrates (spent mushroom compost, ochre, steel slag, and limestone) in passive remediation of metal-containing acid mine drainage

ABSTRACT The potential of selected materials in treating metal-rich acid mine drainage (AMD) has been investigated in a series of batch experiment. The efficiencies of both single and mixed substrates under two conditions i.e. low- and high-concentration solutions containing heavy metals were evaluated. Synthetic metal-containing AMD was used in the experiments treated using spent mushroom compost (SMC), ochre, steel slag (SS), and limestone. Different ratios of treatment materials were incorporated in the substrate mix and were tested in an anoxic condition. In the batch test, physicochemical parameters (pH, redox potential, total dissolved solids, conductivity, and Ca concentration) and heavy metals (Fe, Mn, Pb, Zn, and Al) were analysed. The mixed substrates have shown satisfactory performance in increasing pH with increasing Ca concentration and removing metals. It has been found that SS and ochre played an important role in the treatment of AMD. The results showed that the mixed substrates SM1 (i.e. 10% SMC mixed with 20% ochre, 30% steel slag, and 40% limestone) and SM2 (i.e. 20% SMC mixed with 30% ochre, 40% steel slag, and 10% limestone) were effective in increasing the pH from as low as 3.5–8.09, and removing heavy metals with more than 90% removal efficiencies.