The Ephemeroptera, Plecoptera and Trichoptera (EPT) community structure and the specific sensitivity of certain EPT genera were found to be influenced by water parameters in the rivers of Gunung Jerai Forest Reserve (GJFR) in the north of peninsular Malaysia. The scores of EPT taxa richness of >10 in all rivers indicated all rivers' habitats were non-impacted, having good water quality coinciding with Class I and Class II of Malaysian water quality index (WQI) classification of potable water. The abundance of EPT was very high in Teroi River (9,661 individuals) but diversity was lower (22 genera) than Tupah River which was highly diverse (28 genera) but lower in abundance (4,263 individuals). The lowest abundance and moderate diversity was recorded from Batu Hampar River (25 genera). Baetis spp. and Thalerosphyrus spp., Neoperla spp. and Cheumatopsyche spp. were the most common genera found. Classification for all rivers using EPT taxa Richness Index and WQI gave different category of water quality, respectively. The WQI classified Tupah and Batu Hampar rivers into Class II and Teroi River (Class I) was two classes above the classification of the EPT taxa Richness Index.
The current novel work presents the optimization of factors affecting defluoridation by Al doped ZnO nanoparticles using response surface methodology (RSM). Al doped ZnO nanoparticles were synthesized by the sol-gel method and validated by FTIR, XRD, TEM/EDS, TGA, BET, and particle size analysis. Moreover, a central composite design (CCD) was developed for the experimental study to know the interaction between Al doped ZnO adsorbent dosage, initial concentration of fluoride, and contact time on fluoride removal efficiency (response) and optimization of the process. Analysis of variance (ANOVA) was achieved to discover the importance of the individual and the effect of variables on the response. The model predicted that the response significantly correlated with the experimental response (R2 = 0.97). Among the factors, the effect of adsorbent dose and contact time was considered to have more influence on the response than the concentration. The optimized process parameters by RSM presented the adsorbent dosage: 0.005 g, initial concentration of fluoride: 1.5 g/L, and contact time: 5 min, respectively. Kinetic, isotherm, and thermodynamic studies were also investigated. The co-existing ions were also studied. These results demonstrated that Al doped ZnO could be a promising adsorbent for effective defluoridation for water.
A depth-averaged numerical model was developed to study tidal circulation and suspended sediment transport in the gulf of Khambhat along the west coast of India. The spatial resolution of the model is 750m x 750m. A 2-D fine resolution (150 m x 150 m) model for the lower part of the Narmada estuary is coupled with the coarser gulf model to simulate the flow features in the lower estuary. The model dynamics and basic formulation remain the same for both the gulf model and the estuary model. The models are barotropic, based on the shallow water equations and neglect horizontal diffusion and wind stress terms in the momentum equations. The models are fully non-linear and use a semi-explicit finite difference scheme to solve mass, momentum, and advection- diffusion equation for suspended sediments in a horizontal plane. The erosion and deposition have been computed by an empirically developed source and sink term in the suspended sediment equation. The tide in the gulf is mainly represented in the model by the semi-diurnal M2 constituent. Meanwhile, fresh water discharge from the rivers joining the gulf had also been considered. Numerical experiments were carried out to study the circulation and suspended sediment concentrations in the gulf and estuarine region.
The effects of ozonation, anion exchange resin (AER) and UV/H2O2 were investigated as a pre-treatment to control organic fouling (OF) of ultrafiltration membrane in the treatment of drinking water. It was found that high molecular weight (MW) organics such as protein and polysaccharide substances were majorly responsible for reversible fouling which contributed to 90% of total fouling. The decline rate increased with successive filtration cycles due to deposition of protein content over time. All pre-treatment could reduce the foulants of a Ultrafiltration membrane which contributed to the improvement in flux, and there was a greater improvement of flux by UV/H2O2 (61%) than ozonation (43%) which in turn was greater than AER (23%) treatment. This was likely due to the effective removal/breakdown of high MW organic content. AER gave greater removal of biofouling potential components (such as biodegradable dissolved organic carbon and assimilable organic carbon contents) compared to UV/H2O2 and ozonation treatment. Overall, this study demonstrated the potential of pre-treatments for reducing OF of ultrafiltration for the treatment of drinking water.
Matched MeSH terms: Water Pollutants/radiation effects; Water Pollutants/chemistry; Water Purification/instrumentation; Water Purification/methods*; Drinking Water/chemistry
One of the most interesting water management case studies in Iran is the case of Zayandehrud River, the main river that supplies water to Isfahan Province which is located in Gavkhuni River Basin (GRB). This paper examines the present and future demands for water and determines the extent to which water will be available for agricultural use by the year 2020. Although demand and supply conditions in 2000 were more or less in balance, there was an increase in the supply of some 28% by 2010 due to the completion of the third trans-basin diversion and the development of other local water sources. However, the demand exceeded its supply in 2010 and the basin fell into severe deficit. In this condition, the only way to keep supply and demand in balance is to reduce allocations to agriculture. By 2020, agriculture would only have 5% more water than the present and water supply is only 90% that of the normal, and this would then shrink from 2025 onwards. In other words, agriculture would have to be sacrificed in order to ensure full supplies of water for the other sectors. The scenarios examined reveal that a sustainable agriculture can only be accomplished by water saving practices and management measures, which may further lead to reduced demand, control supplies, and improve the efficiency of water use.
In Malaysia, the use of groundwater can help to meet the increasing water demand. The utilization of the aquifers is currently contributing in water supplies, particularly for the northern states. In this study, quantitative and qualitative assessments were carried out for the groundwater exploitation in the states of Kelantan, Melaka, Terengganu and Perak. The relevant data was acquired from the Department of Mineral and Geoscience, Malaysia. The quantitative assessment mainly included the determination of the use to yield ratio (UTY). The formula was proposed to determine the UTY ratio for aquifers in Malaysia. The proposed formula was applied to determine the maximum UTY ratios for the aquifers located in the states of Kelantan, Melaka, and Terengganu, and were found to be 4.2, 5.2 and 0.6, respectively. This indicated that exploitation of groundwater was beyond the safe limit in the states of Kelantan and Melaka. The qualitative assessment showed that the groundwater is slightly acidic. In addition, the concentrations of iron and manganese were found to be higher than the allowable limits, but the chloride concentration was found within the allowable limit.
Matched MeSH terms: Water; Water Supply; Groundwater
Sungai Sarawak is the most important river in Sarawak. This study was aimed at assessing water quality in the selected stations from Satok bridge to the downstream, Muara Tebas, located along Sungai Sarawak. Water quality trend analysis was conducted to determine the correlation between the water quality parameters. Trend analysis was carried out using Mann-Kendall Test because data collected was non-parametric. Next, Spearman rank was used in order to determine the correlation between parameters. The results obtained and the observation made in this study reveals that the trend exists only for Chemical Oxygen Value (COD). But there are trends for Biochemical Oxygen Demand, (BOD), Dissolved Oxygen (DO), Total Suspended Solid (TSS), Ammoniacal Nitrogen (NH4N) and Turbidity to decrease or increase with no trends between 2007 and 2011. The correlation between parameters is not very strong because there are many determinants of water quality parameters. The result from this study would provide useful information for water quality management in order to maintain and improve the water quality of Sungai Sarawak.
Matched MeSH terms: Water Pollution, Chemical; Water Quality
Microcosm experiments simulating the occurrence of early mortality syndrome/acute hepatopancreatic necrosis disease (EMS/AHPND) in white shrimp production ponds were performed in 30-L aquariums. Healthy white shrimp, Litopenaeus vannamei, were reared in aquariums containing EMS/AHPND-free hatchery or pond water. Raw pond sludge, collected from shrimp ponds where EMS/AHPND had occurred, was added to some test aquariums, while others were treated with sterilized pond sludge. In some aquariums, water pH was increased from 7.5 to 8.8. Microcosms with stable pH (around 7.5) and/or autoclaved sludge served as controls. The combination of raw sludge and increased pH induced EMS/AHPND and killed white shrimp, whereas raw sludge/stable pH and autoclaved sludge/increased pH combinations did not affect healthy shrimp. Thus, EMS/AHPND outbreaks are due not only to the causative agent but also to environmental stresses such as pH fluctuation. These findings contribute to improved management in shrimp production farms.
The shelf life of rambutan is often limited due to rapid water loss from the spinterns and browning of the pericarp. An integrated approach, which combined hot water treatment (HWT) (56 °C for 1 min), oxalic acid (OA) dip (10% for 10 min) and modified atmosphere packaging (MAP), was used to study their effectiveness on the quality of rambutan during storage (10 °C, 90-95% relative humidity). Significant differences were observed in rambutan quality with the combination of MAP + HWT + OA after 20 days of storage. This treatment combination resulted into better retention of firmness and colour (L and a* values) than in the control. Change in the total soluble solid content was significantly delayed however the titratable acidity showed no significant change in comparison to the control at the end of storage.
The hydrological effects of climate variation and land use conversion can occur at various spatial scales, but the most important sources of these changes are at the regional or watershed scale. In addition, the managerial and technical measures are primarily implemented at local and watershed scales in order to mitigate adverse impacts of human activities on the renewable resources of the watershed. Therefore, quantitative estimation of the possible hydrological consequences of potential land use and climate changes on hydrological regime at watershed scale is of tremendous importance. This paper focuses on the impacts of climate change as well as land use change on the hydrological processes of river basin based on pertinent published literature which were precisely scrutinized. The various causes, forms, and consequences of such impacts were discussed to synthesize the key findings of literature in reputable sources and to identify gaps in the knowledge where further research is required. Results indicate that the watershed-scale studies were found as a gap in tropical regions. Also, these studies are important to facilitate the application of results to real environment. Watershed scale studies are essential to measure the extent of influences made to the hydrological conditions and understanding of causes and effects of climate variation and land use conversion on hydrological cycle and water resources.
The widespread distribution of persistent organic pollutants (POPs) in landfill leachate is problematic due to their acute toxicity, carcinogenicity and genotoxicity effects, which could be detrimental to public health and ecological systems. The objective of this study was to evaluate the effective removal of POPs - namely, p-tert-Butylphenol and Pyridine, 3-(1-methyl-2-pyrrolidinyl)-, (S)- - from landfill leachate using locust bean gum (LBG), and in comparison with commonly used alum. The response surface methodology coupled with a Box-Behnken design was employed to optimize the operating factors for optimal POPs removal. A quadratic polynomial model was fitted into the data with the R2 values of 0.97 and 0.96 for the removal of p-tert-Butylphenol and Pyridine, 3-(1-methyl-2-pyrrolidinyl), (S)-, respectively. The physicochemical characteristics of the flocs produced by LBG and alum were evaluated with Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). The infrared spectra of LBG-treated floc were identical with LBG powder, but there was some variation in the peaks of the functional groups, signifying the chemical interactions between flocculants and pollutant particles resulting from POPs removal. The results showed that p-tert-Butylphenol and Pyridine, 3-(1-methyl-2-pyrrolidinyl)-, (S)- obtained 96% and 100% removal using 500 mg/L of LBG at pH 4. pH have a significant effect on POPs removal in leachate. It is estimated that treating one million gallons of leachate using alum (at 1 g/L dosage) would cost US$39, and using LBG (at 500 mg/L dosage) would cost US$2. LBG is eco-friendly, biodegradable and non-toxic and, hence, strongly recommended as an alternative to inorganic coagulants for the treatment of POPs in landfill leachate.
This study analyzes two wind-induced upwelling mechanisms, namely, Ekman transport and Ekman pumping that occur during the southwest monsoon. The results suggest that the coastline of the east coast of Peninsular Malaysia (ECPM) is affected by upwelling with spatiotemporal variations. Characterization of upwelling by using wind-induced upwelling indexes (UIW) indicate the existence of favorable upwelling conditions from May to September. Upwelling intensity increased in May and peaked in August before declining in September, decreasing intensity from the southern tip towards the northern tip along the coastline of the ECPM. The existence of upwelling along the ECPM has resulted in an important difference between the SSTs of the inshore and the oceanic regions. Nonetheless, the use of the SST gradient between the inshore and the oceanic SSTs to characterize upwelling (UISST) was found to be unsuitable because the SST along the ECPM was affected by water advection from the Java Sea and incessant changes in the SST. In order to indicate the major contributor of wind-induced upwelling along the ECPM in terms of the spatiotemporal scale, a comparison between Ekman transport and Ekman pumping was drawn by integrating Ekman pumping with respect to the distance where the positive wind stress curl existed. The estimation of Ekman transport and Ekman pumping indicated that Ekman pumping played a major role in contributing towards upwelling in any particular month during the southwest monsoon along the entire coastline of the ECPM as compared to Ekman transport, which contributed towards more than half of the total upwelling transport. By dividing the ECPM into three coastal sections, we observed that Ekman pumping was relatively predominant in the middle and northern coasts, whereas both Ekman transport and Ekman pumping were equally prevalent in the southern coast.
The widespread occurrence of microplastic has invaded the environment to an extent that it appears to be present throughout the globe. This review investigated the global abundance and distribution of microplastics in marine and freshwater ecosystems. Furthermore, the issues and challenges have been addressed for better findings in microplastics studies. Findings revealed that the accumulation of microplastics varies geographically, with locations, hydrodynamic conditions, environmental pressure, and time. From this review, it is crucial that proper regulations are proposed and implemented in order to reduce the occurrence of microplastics in the aquatic environment. Without appropriate law and regulations, microplastic pollution will eventually threaten human livelihood.
Infiltration caused by rainfall will lead to the changes of moisture content and soil pore water pressure or matric suction of the soil. These changes indicate the behavior of the soil especially during wetting and drying process. This paper presents the experimental test result of rain water infiltration into soil column for two samples of soils. The main objectives were to study the effect of rainfall intensity and duration of soil infiltration process for the forest soil and to compare its result to the gravelly sand. Infiltration experimental in this study involved three main components; water supply system, soil column and instrumentations, including percolation collection system. This study uses two types of tensiometers; 5 and 10 cm long. The results of TDR and tensiometers which were used to obtained moisture content and matric suction, respectively, shows that the system was successfully developed. For the forest soil, the result showed that moisture content of the top section is higher compared with the other sections. On the other hand, for gravelly sand, the moisture content in middle section is higher compared with the top and bottom section of the soil. Meanwhile, matric suction for both soils dropped during rainfall and gradually increases towards drying process. Other than that the comparison of soil matric suction between 5 and 10 cm tensiometers shows significant results for gravelly sand compared to forest soil.
Tropical or subtropical countries are very suitable for the development of solar and heat pump technology. This paper
proposed the integration of air conditioners that exhaust heat with solar energy to enhance the overall efficiency of thermal
energy conversion. The analysis of thermal storage tanks of different volumes showed that a two-ton air conditioner
operating for an hour produced double energy than normal sunshine for a day. With thermal storage tanks of fixed
volume, the integration of air conditioners of different tons with solar energy indicated that air conditioners of less tons
produced faster and more efficient energy conversion. Therefore, this paper proposed that the modification of condenser
in domestic air conditioner into water-cooled condenser not only enhance the energy efficiency of air conditioners but
also increased hot water supplies since hot water from air conditioners could be integrated into solar water heaters. By
doing so, energy conservation and carbon reduction could be achieved.
Water pollution has become a growing threat to human society and natural ecosystem in recent decades, increasing the need to better understand the variabilities of pollutants within aquatic systems. This study presents the application of two chemometric techniques, namely, cluster analysis (CA) and principal component analysis (PCA). This is to classify and identify the water quality variables into groups of similarities or dissimilarities and to determine their significance. Six stations along Kinta River, Perak, were monitored for 30 physical and chemical parameters during the period of 1997-2006. Using CA, the 30 physical and chemical parameters were classified into 4 clusters; PCA was applied to the datasets and resulted in 10 varifactors with a total variance of 78.06%. The varifactors obtained indicated the significance of each of the variables to the pollution of Kinta River.
Matched MeSH terms: Water Pollution; Water Quality
Inaccessible hygiene water sources and sanitation are one of the sustainability issues that need to be solved. An attempt to solve this problem is to change the conventional system used in the water supply and sewage treatment to sustainable water and waste management. To transform the system, companies initially need to map their business value chain. However, this process is often not receiving a full attention by the organisation. In an academic perspective, there are limited studies that map the value chains of water and waste systems. To overcome this limitation, the present study aims to map the value chain processes of the water and wastewater utility companies towards a sustainability solution. A review of related studies is used to conduct this study. Khuzestan Urban Water and Sewage company in Iran has been selected as case studies. The mapping results indicate a lack of sustainability integration in a water management system that leads to ineffective and inefficient water management. Value chain mapping process is significant for practitioners, particularly in the water and sewage companies, as a starting point for transforming their conventional water management systems towards sustainability. Experts at the company stated that value chain mapping as part of value chain analysis enables organisations to increase operational efficiency and eliminate waste by 57%.
In an effort to determine the reason behind excellent nitrate remediation capacity at Kelantan region, a multivariate approach is employed to evaluate extent to which the influence of sea on soil geochemical composition affect variation pattern of groundwater quality. The results obtained from geochemical analysis of paleo-beach soil in coastal site at Bachok revealed multiple redox activity at different soil strata, involving both heterotrophic and autotrophic denitrification. In soil and water analysis, eight of the fourteen hydro-geochemical parameters (conductivity, temperature, soil texture, oxidation reduction potential, pH, total organic carbon, Fe, Cu, Mn, Cl-, SO42-, NO2-, NO3- and PO43-) measured using standard procedures were subjected to multivariate analysis. Evaluation of general variation pattern across the area reveals that the principal component analysis (PCA), hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA) are in consonance with one another on apportioning three parameters (SO42-, Cl- and conductivity) to the coastal sites and two parameters (Fe and NH4+ or NO3-) to inland sites. The step forward analysis of LDA reveals four parameters in order of decreasing significance as Cl-, Fe and SO42-, while the two-way HCA identifies three clusters on location basis, respectively. In addition to the significant data reduction obtained, the results indicate that proximity to sea and location/geological-based influence are more significant than temporal-based influence in denitrification. By extension, the research reveals that influence of labile portion of natural resources is explorable for broader application in other remediation strategies.
Determining the water quality of Bakun Reservoir 13 months after it operates at full supply level is crucial for better understanding of changes in the physicochemical parameters, which may enable the prediction of its effects on the survival of aquatic life in the reservoir. This study determined 13 physicochemical parameters at six stations within the reservoir at fixed depths. The results showed that the minimum 5 mg/L of dissolved oxygen (DO) required for sensitive aquatic organisms was recorded at 6 m depth. However, DO was not detectable at depths exceeding 7 m. The water was acidic at depths of more than 10 m. Turbidity and total suspended solids increased corresponding with depth. Inorganic nitrogen were predominantly in the form of ammonia-nitrogen, creating an unhealthy environment for aquatic life. Concentration of Chl-a was significantly higher at the subsurface water than 30 m depth in four out of six stations. The present study shows changes in water quality as compared to the pre-impounded period and 15 months after the filling phase, in particular, stratification of dissolved oxygen, thermocline conditions and alkalinity. The changes varied according to the distance from the dam and may have been influenced by existing land developments within the area such as the construction of the Murum Hydroelectric Dam, oil palm plantations and timber concessionares. Though the water quality might have deteriorated, further study is needed to determine if this condition will prolong.
This study investigates the spatial variation of water quality parameters in Sungai Setiu Basin at ten different locations from March 2010 to February 2011. The water quality was assessed using the Water Quality Index by Malaysian Department of Environment (DOE-WQI) and classified according to the Malaysia Interim National Water Quality Standard (INWQS). Six water quality parameters embedded in the DOE-WQI were dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), pH, ammoniacal nitrogen (AN) and total suspended solid (TSS). In addition, this study also examined the changes in water quality over the past 10 years by comparing the present water quality to the previous works. The overall mean WQI value obtained was 84.0 which indicate that the Sungai Setiu basin is in clean condition and all measured water quality parameters gave value within the permissible limits of the INWQS classification except for pH which fall in Class III. It can be concluded that water quality in Sungai Setiu does not varies greatly over a decade. Hence continuous monitoring is needed to improve the water quality and minimize water pollution.
Matched MeSH terms: Water Pollution; Water Quality