Landfill leachate is one of the sources of surface water pollution in Selangor State (SS), Malaysia. Leachate volume prediction is essential for sustainable waste management and leachate treatment processes. The accurate estimation of leachate generation rates is often considered a challenge, especially in developing countries, due to the lack of reliable data and high measurement costs. Leachate generation is related to several variable factors, including meteorological data, waste generation rates, and landfill design conditions. Large variations in these factors lead to complicated leachate modeling processes. The aims of this study are to determine the key elements contributing to leachate production and then develop an adaptive neural fuzzy inference system (ANFIS) model to predict leachate generation rates. Accuracy of the final model performance was tested and evaluated using the root mean square error (RMSE), the mean absolute error (MAE), and the correlation coefficient (R). The study results defined dumped waste quantity, rainfall level, and emanated gases as the most significant contributing factors in leachate generation. The best model structure consisted of two triangular fuzzy membership functions and a hybrid training algorithm with eight fuzzy rules. The proposed ANFIS model showed a good performance with an overall correlation coefficient of 0.952.
Water contamination by herbicides and chelating agents is increasing mainly due to the
increasing agricultural activities. Water contamination by these compounds has become a
concern due to their adverse effects to the environment and humans. Seven sampling sites of
water sources in Selangor and Johor were chosen for the study. Contamination level of
Mecoprop (MCCP), Nitrilotriacetic acid (NTA) and Ethylenediaminetetraacetic acid (EDTA) in
these water body areas was determined by using Gas Chromatography-Electron Capture
Detector (GC-ECD). Our results indicated that water samples of Sungai Melot in Selangor
showed the highest presence of EDTA. MCCP was detected at a high level at Sungai Sarang
Buaya, Johor while NTA showed similar level of concentration at three different sites, Ladang
10, Ladang Sayur and Mardi, Selangor.
Population in urban centers in Kenya is increasing rapidly due to rural urban migration in search of better paying jobs. This migration has resulted in unauthorized settlements in the various urban centers. The income per capital of these people is less than a dollar a day. The amount of money is inadequate for survival and this has resulted into cultivating on open grounds for food crops. Unfortunately, these slums have come up along rivers, which carry, wastewater from household and industries. This wastewater is rich in heavy metals and the inhabitants of these areas use this contaminated water for irrigating their crops. The food crops from such areas have very high levels of heavy metals. The present study has screened Zea mays, Commelina bengalensis and Amaranthus hybridus for their ability to bioaccumulate these metals from contaminated soils using atomic absorption spectrophotometer (AAS). The results obtained showed that the C. bengalensis has high potential for removal of Cu, Pb and Cd metals as compared to the Zea mays and Amaranthus hybridus even though, results showed that C. bengalensis has a low potential for the removal of Zn as compared to Zea mays and Amaranthus hybridus.
Occurrence of pharmaceutical residues in drinking water has been widely reported in countries that have registered steady economic growth. This can exert concerns among the general consumers, prompting them to explore the potential human health risks associated with continuous exposure to pharmaceuticals. However, such an occurrence is rarely reported in developing or under-developed countries. To give more contexts, this study looked at the presence of nine pharmaceutical residues in drinking water (amoxicillin, caffeine, chloramphenicol, ciprofloxacin, dexamethasone, diclofenac, nitrofurazone, sulfamethoxazole, and triclosan) at Putrajaya residential area in Malaysia. Additionally, the potential health risks associated with contaminated drinking water were investigated. This study has found the presence of pharmaceutical residue concentrations up to 0.38 ng/L, with the highest concentration of caffeine (0.38 ng/L) and the lowest concentration of diclofenac (0.14 ng/L). In comparison, all the nine pharmaceutical residues were substantially lower than previously reported studies. In general, Hazard Quotient (HQ) values indicated that low potential health hazards were present for all age groups. Nevertheless, quantitative occurrences of pharmaceutical residues in drinking water will help guide future toxicological studies to examine other chronic effects, while canvassing for proper framework to look into the water risk management and regulation in Malaysia.
Water from the dental unit waterlines (DUWLs) is known to contaminate with microbial from the biofilm that formed in the tubing system. The water quality from DUWLs is important to patients and dental health care professionals as they could be infected either directly from the contaminated water or aerosol that is generated during dental procedures. Suppliers claimed that dental units supplied to the hospital can only use a specific disinfectant which is uneconomic compared with the others. The aims of this study were to evaluate and compare the efficacy of different disinfectant on the water quality of DUWLs. Four disinfectants (Calbenium, A-dec ICX tablet, Dentel 5, Metassys) and distil water were evaluated. 350 mL water sample was collected separately, from the outlet of high-speed handpiece, scaler, 3-ways syringe and cup filler into a sterile thiosulfate bag on the 1st, 2nd, 4th, 8th, 12th and 24th weeks of the study. The samples were tested on the following day for total viable count (TVC). There is significant difference in the efficacies of the different disinfectants. Only one disinfectant consistently produces water quality within the recommended level of American Dental Association (ADA). Within the limitation of this study, it was found that there is alternative disinfectant that can reduce the TVC to the level recommended by ADA. However, the water qualities produced with these disinfectants were not consistent although they did not cause any technical problem to the dental units during the period of study.
Heavy metal ion contamination in water poses a significant risk to human health as well as to the environment. Millions of tons of agricultural wastes are produced from oil palm plantations which are challenging to manage. In this study, we converted palm kernel shells (PKS) from a palm oil plantation into activated carbon (AC) having a surface area of 1099 m2/g using phosphoric acid as an activator. The prepared material was characterized using BET, XRD, Raman, FESEM and FTIR analyses. The AC was applied for the treatment of heavy-metal-contaminated water, and different parameters; the pH, adsorbent dosage, contact time and metal ion concentrations were varied to determine the optimal conditions for the metal ion adsorption. Different kinetic models; the zeroth, first-order and second-order, and Freundlich and Langmuir isotherm models were used to determine the mechanism of metal ion adsorption by the AC. Under the optimized conditions, Cr6+ and Pb2+ were removed completely, while Zn2+ and Cd2+ were more than 80% removed. This is a greener approach in which an agricultural waste, PKS is converted into a useful product, activated carbon and subsequently applied for the treatment of heavy metal-contaminated water.
Principal component analysis (PCA) is capable of handling large sets of data. However, lack of consistent method in data pre-treatment and its importance are the limitations in PCA applications. This study examined pre-treatments methods (log (x + 1) transformation, outlier removal, and granulometric and geochemical normalization) on dataset of Mengkabong Lagoon, Sabah, mangrove surface sediment at high and low tides. The study revealed that geochemical normalization using Al with outliers removal resulted in a better classification of the mangrove surface sediment than that outliers removal, granulometric normalization using clay and log (x + 1) transformation. PCA output using geochemical normalization with outliers removal demonstrated associations between environmental variables and tides of mangrove surface sediment, Mengkabong Lagoon, Sabah. The PCA outputs at high and low tides also provided to better interpret information about the sediment and its controlling factors in the intertidal zone. The study showed data pre-treatment method to be a useful procedure to standardize the datasets and reducing the influence of outliers.
Ralstonia mannitolilytica is a gram negative soil bacterium. Ralstonia infection though rare, has become the emerging nosocomial pathogens in hospital settings. Various clinical manifestations had been described as well as the mode of transmission. Despite its low virulence factor, it is able to survive under harsh condition and this may potentially cause significant morbidity and mortality especially in immunocompromised patients. Outbreak of Ralstonia mannitolilytica infections in the hospital are typically associated with contaminated medical supplies or instruments. We described here a case of Ralstonia mannitolilytica infection in a dialysis patient that occurred during the municipal reservoir water contamination crisis. In this report, we will also describe the behaviour of Ralstonia genus and its 4 main species, namely R. pickettii, R. solanacearum, R. insidiosa, and R. mannitolilytica and the choices of antibiotic therapy based on literature review.
Dissolved organic matter (DOM) was characterised in water samples sampled in the Lower Kinabatangan River Catchment, Sabah, Malaysia between October 2009 and May 2010. This study aims at: (i) distinguishing between the quality of DOM in waters draining palm oil plantations (OP), secondary forests (SF) and coastal swamps (CS) and, (ii) identifying the seasonal variability of DOM quantity and quality. Surface waters were sampled during fieldwork campaigns that spanned the wet and dry seasons. DOM was characterised optically by using the fluorescence Excitation Emission Matrix (EEM), the absorption coefficient at 340 nm and the spectral slope coefficient (S). Parallel Factor Analysis (PARAFAC) was undertaken to assess the DOM composition from EEM spectra and five terrestrial derived components were identified: (C1, C2, C3, C4 and C5). Components C1 and C4 contributed the most to DOM fluorescence in all study areas during both the wet and dry seasons. The results suggest that component C4 could be a significant (and common) PARAFAC signal found in similar catchments. Peak M (C2 and C3) was dominant in all samples collected during wet and dry seasons, which could be anthropogenic in origin given the active land use change in the study area. In conclusion, there were significant seasonal and spatial variations in DOM which demonstrated the effects of land use cover and precipitation amounts in the Kinabatangan catchment.
Matched MeSH terms: Water Pollution/statistics & numerical data
The commonly adopted method of dumping dredge spoil at sea using split-hull barges leads to considerable sediment loss to the water column and a subsequent dispersion of fine material that can pose a risk to sensitive "downstream" habitats such as coral reefs. Containing sediment loads using stitched closed geotextile bags is practiced for minimizing loss of contaminated sediment, but is expensive in terms of operational efficiency. Following promising observations from initial laboratory trials, the plunging of partially shielded sediment loads, released on open sea, was studied. The partial shielding was achieved with rigid, open containers as well as flexible, open bags. The loss of sediment from these modes of shielding was measured, and it was observed that even limited and unstitched shielding can be effective in debilitating the entrainment of water into the descending load. In particular, long-sleeved flexible bags practically self-eliminated the exposure of the load and thus losses.
Matched MeSH terms: Water Pollution/prevention & control*
This case study uses several univariate and multivariate statistical techniques to evaluate and interpret a water quality data set obtained from the Klang River basin located within the state of Selangor and the Federal Territory of Kuala Lumpur, Malaysia. The river drains an area of 1,288 km(2), from the steep mountain rainforests of the main Central Range along Peninsular Malaysia to the river mouth in Port Klang, into the Straits of Malacca. Water quality was monitored at 20 stations, nine of which are situated along the main river and 11 along six tributaries. Data was collected from 1997 to 2007 for seven parameters used to evaluate the status of the water quality, namely dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, suspended solids, ammoniacal nitrogen, pH, and temperature. The data were first investigated using descriptive statistical tools, followed by two practical multivariate analyses that reduced the data dimensions for better interpretation. The analyses employed were factor analysis and principal component analysis, which explain 60 and 81.6% of the total variation in the data, respectively. We found that the resulting latent variables from the factor analysis are interpretable and beneficial for describing the water quality in the Klang River. This study presents the usefulness of several statistical methods in evaluating and interpreting water quality data for the purpose of monitoring the effectiveness of water resource management. The results should provide more straightforward data interpretation as well as valuable insight for managers to conceive optimum action plans for controlling pollution in river water.
Matched MeSH terms: Water Pollution, Chemical/statistics & numerical data*
The status report on metal pollution in tropical estuaries and coastal waters is important to understand potential environmental health hazards. Detailed baseline measurements were made on physicochemical parameters (pH, temperature, redox potential, electrical conductivity, salinity, dissolved oxygen, total dissolved solid), major ions (Na, Ca, Mg, K, HCO3, Cl, SO4 and NO3) and metals concentrations ((27)Al, (75)As, (138)Ba, (9)Be, (111)Cd, (59)Co, (63)Cu, (52)Cr, (57)Fe, (55)Mn, (60)Ni, (208)Pb, (80)Se, (66)Zn) at estuaries and coastal waters along the Straits of Malacca. Principal component analysis (PCA) was employed to reveal potential pollution sources. Seven principal components were extracted with relation to pollution contribution from minerals-related parameters, natural and anthropogenic sources. The output from this study will generate a profound understanding on the metal pollution status and pollution risk of the estuaries and coastal system.
Matched MeSH terms: Water Pollution, Chemical/statistics & numerical data
Information on the pollution level and the influence of hydrologic regime on the stormwater pollutant loading in tropical urban areas are still scarce. More local data are still required because rainfall and runoff generation processes in tropical environment are very different from the temperate regions. This study investigated the extent of urban runoff pollution in residential, commercial, and industrial catchments in the south of Peninsular Malaysia. Stormwater samples and flow rate data were collected from 51 storm events. Samples were analyzed for total suspended solids, 5-day biochemical oxygen demand, chemical oxygen demand, oil and grease (O&G), nitrate nitrogen (NO3-N), nitrite nitrogen, ammonia nitrogen, soluble reactive phosphorus, total phosphorus (TP), and zinc (Zn). It was found that the event mean concentrations (EMCs) of pollutants varied greatly between storm characteristics and land uses. The results revealed that site EMCs for residential catchment were lower than the published data but higher for the commercial and industrial catchments. All rainfall variables were negatively correlated with EMCs of most pollutants except for antecedent dry days (ADD). This study reinforced the earlier findings on the importance of ADD for causing greater EMC values with exceptions for O&G, NO3-N, TP, and Zn. In contrast, the pollutant loadings are influenced primarily by rainfall depth, mean intensity, and max 5-min intensity in all the three catchments. Overall, ADD is an important variable in multiple linear regression models for predicting the EMC values in the tropical urban catchments.
Matched MeSH terms: Water Pollution, Chemical/statistics & numerical data*
Rivers play a significant role in providing water resources for human and ecosystem survival and health. Hence, river water quality is an important parameter that must be preserved and monitored. As the state of Selangor and the city of Kuala Lumpur, Malaysia, are undergoing tremendous development, the river is subjected to pollution from point and non-point sources. The water quality of the Klang River basin, one of the most densely populated areas within the region, is significantly degraded due to human activities as well as urbanization. Evaluation of the overall river water quality status is normally represented by a water quality index (WQI), which consists of six parameters, namely dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, suspended solids, ammoniacal nitrogen and pH. The objectives of this study are to assess the water quality status for this tropical, urban river and to establish the WQI trend. Using monthly WQI data from 1997 to 2007, time series were plotted and trend analysis was performed by employing the first-order autocorrelated trend model on the moving average values for every station. The initial and final values of either the moving average or the trend model were used as the estimates of the initial and final WQI at the stations. It was found that Klang River water quality has shown some improvement between 1997 and 2007. Water quality remains good in the upper stream area, which provides vital water sources for water treatment plants in the Klang valley. Meanwhile, the water quality has also improved in other stations. Results of the current study suggest that the present policy on managing river quality in the Klang River has produced encouraging results; the policy should, however, be further improved alongside more vigorous monitoring of pollution discharge from various point sources such as industrial wastewater, municipal sewers, wet markets, sand mining and landfills, as well as non-point sources such as agricultural or urban runoff and commercial activity.
Matched MeSH terms: Water Pollution, Chemical/statistics & numerical data*
Surface water is one of the essential resources for supporting sustainable development. The suitability of such water for a given use depends both on the available quantity and tolerable quality. Temporary status for a surface water quality has been identified extensively. Still the suitability of the water for different purposes needs to be verified. This study proposes a water quality evaluation system to assess the aptitude of the Selangor River water for aquatic biota, drinking water production, leisure and aquatic sport, irrigation use, livestock watering, and aquaculture use. Aptitude of the water has been classified in many parts of the river segment as unsuitable for aquatic biota, drinking water production, leisure and aquatic sport as well as aquaculture use. The water quality aptitude classes of the stream water for nine locations along the river are evaluated to contribute to decision support system. The suitability of the water for five different uses and its aquatic ecosystem are verified.
Matched MeSH terms: Water Pollution, Chemical/statistics & numerical data
In Malaysia, landfills are being filled up rapidly due to the current daily generation of approximately 30,000 tonnes of municipal solid waste. This situation creates the crucial need for improved landfilling practices, as sustainable landfilling technology is yet to be achieved here. The objective of this paper is to identify and evaluate the development and trends in landfilling practices in Malaysia. In 1970, the disposal sites in Malaysia were small and prevailing waste disposal practices was mere open-dumping. This network of relatively small dumps, typically located close to population centres, was considered acceptable for a relatively low population of 10 million in Malaysia. In the 1980s, a national programme was developed to manage municipal and industrial wastes more systematically and to reduce adverse environmental impacts. The early 1990s saw the privatization of waste management in many parts of Malaysia, and the establishment of the first sanitary landfills for MSW and an engineered landfill (called 'secure landfill' in Malaysia) for hazardous waste. A public uproar in 2007 due to contamination of a drinking water source from improper landfilling practices led to some significant changes in the government's policy regarding the country's waste management strategy. Parliament passed the Solid Waste and Public Cleansing Management (SWPCM) Act 2007 in August 2007. Even though the Act is yet to be implemented, the government has taken big steps to improve waste management system further. The future of the waste management in Malaysia seems somewhat brighter with a clear waste management policy in place. There is now a foundation upon which to build a sound and sustainble waste management and disposal system in Malaysia.
Matched MeSH terms: Water Pollution/prevention & control
The distribution of total petrogenic hydrocarbon was investigated in the subsurface water of Setiu Wetland from July to October 2008. The concentration was quantified by UV-fluorescence spectroscopy and ranged from 4 to 121 μg/L (mean 60 ± 41 μg/L). Higher total petrogenic hydrocarbon concentrations were found in area with high boating activities suggesting that the contribution is likely related to fossil fuel combustion. The present study also revealed that the total petrogenic hydrocarbon values are still lower that those reported in Malaysian coastal waters.
Matched MeSH terms: Water Pollution, Chemical/statistics & numerical data
The contamination of groundwater by heavy metal, originating either from natural soil sources or from anthropogenic sources is a matter of utmost concern to the public health. Remediation of contaminated groundwater is of highest priority since billions of people all over the world use it for drinking purpose. In this paper, thirty five approaches for groundwater treatment have been reviewed and classified under three large categories viz chemical, biochemical/biological/biosorption and physico-chemical treatment processes. Comparison tables have been provided at the end of each process for a better understanding of each category. Selection of a suitable technology for contamination remediation at a particular site is one of the most challenging job due to extremely complex soil chemistry and aquifer characteristics and no thumb-rule can be suggested regarding this issue. In the past decade, iron based technologies, microbial remediation, biological sulphate reduction and various adsorbents played versatile and efficient remediation roles. Keeping the sustainability issues and environmental ethics in mind, the technologies encompassing natural chemistry, bioremediation and biosorption are recommended to be adopted in appropriate cases. In many places, two or more techniques can work synergistically for better results. Processes such as chelate extraction and chemical soil washings are advisable only for recovery of valuable metals in highly contaminated industrial sites depending on economical feasibility.
The purpose of this study was to investigate the potential risk of pretilachlor, thiobencarb, and propanil pollutants in the water system of the rice fields of the Muda area. The study included two areas that used different irrigation systems namely non-recycled (N-RCL) and recycled (RCL) water. Regular water sampling was carried out at the drainage canals during the weeding period from September to October 2006 in the main season of 2006/2007 and April-May 2007 in off season of 2007. The herbicides were extracted by the solid-phase extraction method and identified using a GC-ECD. Results showed that the procedure for identification of the three herbicides was acceptable based on the recovery test values, which ranged from 84.1% to 96.9%. A wide distribution pattern where more than 79% of the water samples contained the herbicide pollutants was observed at both the areas where N-RCL and RCL water was supplied for the two seasons. During September to October 2006, high weedicide residue concentration was observed at the N-RCL area and it ranged from 0.05 to 1.00 μg/L for pretilachlor and propanil and 10-25 μg/L for thiobencarb. In the case of the area with RCL water, the weedicide residue ranged from 1 to 5 μg/L for pretilachlor and propanil and 10-25 μg/L for thiobencarb. The highest residue level reached was 25-50, 50-100, and 100-200 μg/L for pretilachlor, propanil, and thiobencarb, respectively. During April to May 2007, high residue concentration frequently occurred at the area supplied with N-RCL irrigation water and it ranged from 0.05 to 1.00, 10 to 25, and 25 to 50 μg/L for pretilachlor, propanil, and thiobencarb, respectively. The highest residue level reached was 25-50 μg/L for pretilachlor and 100-200 μg/L for propanil and thiobencarb. There was an accelerated increase in the concentration of the herbicide residues, with the maximum levels reached at the early period of weedicide application, followed by a sharp decrease after the rice fields were completely covered with the rice crop. During the main season of 2006/2007, the concentration of propanil residue gradually rose, although that of the other herbicides declined.
Matched MeSH terms: Water Pollution, Chemical/statistics & numerical data