Water Quality Standard Setting Research Articles

Hybrid multi-chamber system for enhanced removal of boron during water treatment/desalination without chemical usage

The efficiency of boron removal during water treatment and desalination is insufficient to meet the water quality standard set by the World Health Organization. Boron can exist in its two natural forms in water, depending on the water pH. At low and high pH, boron tends to exist as boric acid and borate ion, which are neutral and negatively charged, respectively. In this study, we developed a multi-chamber boron control system. For the control group (nanofiltration (NF) and reverse osmosis (RO)), the pH was controlled to enhance the boron removal efficiency. As expected, the boron removal efficiency at pH 11 (RO: 95–98%, NF: 91%) was higher than that at pH 8 (RO: 85–87%, NF: 80%). Additionally, activated carbon was introduced in the developed system (forward osmosis-NF/RO hybrid processes within the draw-solution chamber). Powdered activated carbon was more effective than granulated activated carbon in adsorbing boron molecules, with the maximum adsorption capacities (qm) of the former and latter being 2.33 and 1.33 mg g−1, respectively. A simple economic analysis was performed to determine the applicability of the multi-chamber boron control system for the economical production of high-quality water with minimal boron concentration. The unit cost of the multi-chamber boron control system (0.26 USD ton−1) was significantly lower than that associated with single NF and RO processes (0.64–1.62 USD ton−1). The multi-chamber boron control system thus represents an economical alternative that can achieve a higher product water quality compared with existing processes.

ANALISIS KUALITAS AIR SUMUR GALI BERDASARKAN INDEKS PENCEMARAN SERTA PERSEPSI DAN PERILAKU MASYARAKAT DI DESA SANUR KAUH DENPASAR SELATAN

The goal of the study was to analyze the water quality of dug wells based on Bali Governor Regulation No. 16 of 2016 and Regulation of the Minister of Health of the Republic of Indonesia No.492/Menkes/Per/IV/2010, which analyzes the quality status of dug well water and its distribution based on the Pollution Index (IP) value and community behavior in Sanur Kauh Village, South Denpasar. Purposive sampling at three stations with three repeats was used to determine the sample. Temperature, color, taste, odor, TDS, turbidity, pH, DO, BOD, COD, Nitrate (NO3-N), Phosphate (PO4), Chloride (Cl-), Iron (fe), E. Coli, and total coliforms were among the parameters measured in situ and ex situ (laboratory). Questionnaires and interviews with respondents who used dug well water were used to collect data on perception and behavior of components (households, business actors and/or activities, farmers, and the government), which were analyzed using a Likert scale and binary model. Surfer and GIS were used to map the water from an excavated well. The results of the analysis of the quality of dug well water exceeded the Class I Water quality standard set by Bali Governor Regulation No. 16 of 2016 for BOD, COD, phosphate, nitrate, iron, total coliform, and turbidity parameters, as well as the Indonesian Minister of Health Regulation No.492/Menkes /Per/IV/2010 for BOD, COD, phosphate, nitrate, iron, total coliform, and turbidity parameters Population activities, pollution sources, climate, soil type and topography, height and depth of the well all influence the water quality status of dug wells, which is classified as moderately polluted. The average community's impression of the provision of dug well water, water pollution, and waste management is positive, and the average community conduct is positive.
 Keywords: Shallow Groundwater, Groundwater Quality, Quality Status, Perception, Behavior

Analyzing the Impact of Learning Rate in development of the Prediction Model using Artificial Neural Network

Water Quality (WQ) modeling and forecasting are very challenging for water management bodies due to the complex and nonlinear relationship between the parameters responsible for determining water quality. The main focus of this paper is the water quality prediction of the Ganges River by analyzing the impact of one of the critical configuration parameters of a neural network known as the learning rate. The proposed prediction model based on an artificial neural network (ANN) consists of different sets of experiments performed by comparing twelve different training functions against the variation in learning rates. A total of 360 experiments have been conducted on the dataset collected over the period 2001 to 2015 with five stations along the Ganges River in the state of Uttarakhand, India. All experiments have been conducted in MATLAB software. The ANN-based program is written in Matlab’s NN-Toolbox. As input parameters, we have used temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), and total coliform. The water quality standard set by the Central Pollution Control Board of India has been used. The performance of the developed model has been calculated based on Mean Squared Error (MSE), Root Mean Squared Error (RMSE), Mean Absolute Percentage Error (MAPE). Trail training function-based artificial neural network models indicate higher predictive accuracy when compared to other models developed using the remaining eleven training functions when the learning rate is set to 0.04. In conclusion, ANN has the ability to efficiently predict the water quality of rivers and the learning rate has a greater impact on the development of such predictive models. So, it is required to be tuned very carefully.

Household Water Filtration Technology to Ensure Safe Drinking Water Supply in the Langat River Basin, Malaysia

Populations in the Langat River Basin, Malaysia, frequently experience water supply disruption due to the shutdown of water treatment plants (WTPs) mainly from the chemical pollution as well as point and non-point sources of pollution. Therefore, this study investigated the aluminium (Al), arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb) concentrations in the drinking water supply chain at the basin because of its prolonged persistence and toxic characteristics in the aquatic environment. Three replicates of water samples were collected from the river, outlets of WTPs, household tap and filtered water, respectively, in 2015, for analysis by Inductively Coupled Plasma Mass Spectrometry. Higher concentration of these metals was found in household tap water than in the treated water at the WTPs; however, the concentration of these metals at the four stages of the drinking water supply chain conformed to the drinking water quality standard set by the World Health Organization. The Mann-Whitney and Kruskal-Wallis tests also found that metal concentration removal significantly varied among the eight WTPs as well as the five types of household water filtration systems. With regards to the investigated household filtered water, the distilled filtration system was found to be more effective in removing metal concentration because of better management. Therefore, a two-layer water filtration system could be introduced in the Langat River Basin to obtain safe drinking water supply at the household level.

Assessment of Macroinvertebrates as Bioindicators of Water Quality in the Littoral Zone of Lake Mainit, Philippines

Water quality in the lake littoral zone influence habitat complexity. This study determined the relationships of macroinvertebrates in response to water physicochemical parameters in ten littoral zone stations across four municipalities of Lake Mainit Philippines. Macroinvertebrates were collected following the standard protocol for littoral areas with modifications and taxa groupings were assigned based on sensitivity to pollution. Water Quality Index (WQI) from the identified bioindicator species was computed. Results revealed that all physicochemical parameters of the ten sampling stations passed the water quality standard set by DAO 2016, except for the pH and temperature readings of Mansayao and Tagbuyawan. Out of 20, 924 macroinvertebrates collected, 16 species were identified from 13 families. Station Mansayao exhibited higher species diversity (H’=1.98). No EPT (Ephemeroptera, Plecoptera, Trichoptera) species were observed across stations. Most of the macroinvertebrates collected were under Taxa 2 (50%) and Taxa 3 (50%), the presence of which, indicates moderate to poor water quality. The WQIs range from 3.1-3.7, which means the stations have “rather dirty to average” and “dirty water”, except for the San Roque station (WQI=2.5), which showed a polluted water quality. Of the 16 species of macroinvertebrates collected, only ten species showed moderate positive association to pH, dissolve oxygen, temperature and Total Dissolved Solids. Littoral zones of the Lake Mainit still support and harbor a variety of aquatic macroinvertebrates. However, the abundance of pollutiontolerant species indicates a declining water quality due to the influence of anthropogenic activities surrounding the lake.

Carcinogenic and non-carcinogenic health risk of arsenic ingestion via drinking water in Langat River Basin, Malaysia.

The prolonged persistence of toxic arsenic (As) in environment is due to its non-biodegradable characteristic. Meanwhile, several studies have reported higher concentrations of As in Langat River. However, it is the first study in Langat River Basin, Malaysia, that As concentrations in drinking water supply chain were determined simultaneously to predict the health risks of As ingestion. Water samples collected in 2015 from the four stages of drinking water supply chain were analysed for As concentration by inductively coupled plasma mass spectrometry. Determined As concentrations along with the time series data (2004-2015) were significantly within the maximum limit 0.01mg/L of drinking water quality standard set by World Health Organization. The predicted As concentration by auto-regression moving average was 3.45E-03mg/L in 2020 at 95% level based on time series data including climatic control variables. Long-term As ingestion via household filtration water at Langat Basin showed no potential lifetime cancer risk (LCR) 9.7E-06 (t = 6.68; p = 3.37E-08) as well as non-carcinogenic hazard quotient (HQ) 4.8E-02 (t = 6.68; p = 3.37E-08) risk at 95% level. However, the changing landscape, ex-mining ponds and extensive use of pesticides for palm oil plantation at Langat Basin are considered as the major sources of increased As concentration in Langat River. Therefore, a two-layer water filtration system at Langat Basin should be introduced to accelerate the achievement of sustainable development goal of getting safe drinking water supply.

Assessment of spring water quality and associated health risks in a high-level natural radiation area, North Iran.

In this study, the spring water quality of a high natural background radiation region in North Iran was evaluated by measuring hydrochemical characteristics and concentration of potentially toxic elements (PTEs) and activity concentration of radioactive elements. The carcinogenicity potential from exposure to PTEs and radioactive elements was also investigated using probabilistic approach. The hydrochemical properties of water samples revealed that there were two different water types in the study area: (1) non-thermal Ca-HCO3 type and (2) thermal Na-Cl type. The concentrations of Al, Cd, Cr, Cu, Pb, Mo, Ni, Sb, Zn, and 40K were within the recommended water quality standard set by the World Health Organization (WHO). Elevated concentrations of As, Mn, Hg, 226Ra, and 232Th occur in Na-Cl water type while elevated concentrations of Fe occur in Ca-HCO3 water type. Also, health complications of dermal contact (via balneology or bathing) are within the safe limits. The major concern regarding the contaminated springs is the possibility of soil and groundwater contamination through uncontrolled runoff and spa effluents. Preventing the spread of toxic constituents in the study area via high-risk spring water requires periodic monitoring, and applying control measures where necessary.

Potential Study of Water Extraction from Selected Plants

Water is absorbed by the roots of a plant and transported subsequently as a liquid to all parts of the plant before being released into the atmosphere as transpiration. In this study, seven(7)selected plant species collected from urban, rural and forested areas were studied and characterized. The water was collected using transparent plastic bag that being tied to the tree branches. Then, the vapouris water trapped inside the plastic bag and through the condensation process, it become water droplets. Water quality parameters such as temperature, pH value, DO, turbidity, colour, magnesium, calcium, nitrate and chloride were analyzed. The analysis was compared to drinking water quality standard set by the Ministry of Health Malaysia. Based on the results, it shows that banana leaf has a higher rate of water extraction compared to others. Thus, the plant can be categorised as a helpful guide for emergency use of water or as an alternative source to survival.

English

The concentration of trace metals were determined in the world of waters River Benue within Makurdi Metropolitan area using atomic absorption spectrophotometer for two seasons. The mean concentration of the heavy metals Pb, Ni, Cu, Cr, Cd and Al obtained in mg/L were 0.42, 0.39, 0.35, 1.58, 0.19 and 0.04 respectively. There was no significant difference in the concentration of heavy metals across the studied stations (P>0.05). However, during the seasons there was significant difference in the concentration of heavy metals (P<0.05). The mean values of the heavy metals (Pb, Ni, Cr, Cd and Al) in the waters of River Benue were above the drinking water quality standard set by WHO except for Cu. There is clear evidence that River Benue within Makurdi is polluted with heavy metals and there is need to monitor the River regularly by the regulatory authority. The waters of River Benue should not be consumed without adequate treatment.   Key words: Trace metals, River Benue, contamination. &nbsp

Studies on contamination of surface waters of river Benue with trace elements at Makurdi, Benue State, Nigeria

The concentration of trace metals were determined in the world of waters River Benue within Makurdi Metropolitan area using atomic absorption spectrophotometer for two seasons. The mean concentration of the heavy metals Pb, Ni, Cu, Cr, Cd and Al obtained in mg/L were 0.42, 0.39, 0.35, 1.58, 0.19 and 0.04 respectively. There was no significant difference in the concentration of heavy metals across the studied stations (P>0.05). However, during the seasons there was significant difference in the concentration of heavy metals (P<0.05). The mean values of the heavy metals (Pb, Ni, Cr, Cd and Al) in the waters of River Benue were above the drinking water quality standard set by WHO except for Cu. There is clear evidence that River Benue within Makurdi is polluted with heavy metals and there is need to monitor the River regularly by the regulatory authority. The waters of River Benue should not be consumed without adequate treatment. Key words: Trace metals, River Benue, contamination.

A comparison of the short-term toxicity of cadmium to indigenous and alien gammarid species

Amphipods play an important role in many aquatic ecosystems and are commonly used in ecotoxicology and ecosystem health assessment. Several alien gammarids have been introduced in many regions of the world during the last decades. In this study, we investigated if differences in cadmium sensitivity occurred between (1) different species belonging to the family Gammaridae and (2) different populations of the same species originating from a polluted or a non-polluted site. The acute cadmium toxicity to two indigenous (Gammarus pulex and Gammarus fossarum) and four alien (Dikerogammarus villosus, Echinogammarus berilloni, Gammarus roeseli and Gammarus tigrinus) gammarids occurring in Belgium was tested. Significant differences (P < 0.05) in median lethal concentrations (LC(50)) were found between the different species, with 72 h-LC50s ranging from 6.3 to 268 μg/l and 96 h-LC50s from 4.7 to 88.9 μg/l. No clear trend in Cd sensitivity was found when comparing indigenous and alien gammarids. D. villosus, an alien invasive species, was the most sensitive to Cd toxicity and E. berilloni, another alien species, the least sensitive. In addition, larger Gammarid species were more sensitive to Cd toxicity than smaller ones. No significant differences were found between populations of the same species originating from metal polluted sites or non-polluted sites. Overall, our results showed that considerable differences in Cd sensitivity exist between gammarid species, which should be taken into consideration in environmental risk assessment and water quality standard setting. Finally, our data suggest that alien gammarids would not have an advantage over indigenous gammarids in Cd contaminated environments.

Influence of Rock Mineralogy on Subsurface Water in Ado-Ekiti, Nigeria

Sudden geometric increase in population of Ado-Ekiti has lead to an increase in demand for water and harnessing of subsurface water reserve. This research investigated the possible infiltration of dissolved mineral from weathered rock into subsurface water in the area (basement complex rocks), and comparing the mineral level with the set standard for quality water by the World Health Organization Physical test were carried out on hardness, colour, odour, conductivity, pH, and turbidity. Chemical test for sodium (Na+) and potassium (K2+) was also done using experimental scientific set standard. The analysis of the sodium, potassium ions, and the conductivity of the water indicate that dissolved mineral from rocks have great influence on the underground water property. The level of the dissolved mineral is within the acceptable limit for water quality standard set by the W.H.O. Sourcing for underground water should not be based on hydro geological variable alone but possible chemical interference from the geology of the environment (rock type).African Research Review Vol. 2 (2) 2008 pp. 175-186

Predicting the Frequency of Water Quality Standard Violations Using Bayesian Calibration of Eutrophication Models

The water quality standard setting process usually relies on mathematical models with strong mechanistic basis, as this provides assurance that the model will more realistically project the effects of alternative management schemes. From an operational standpoint, the interpretation of model results should be coupled with rigorous error analysis and explicit consideration of the predictive uncertainty and natural variability. In this study, our main objective is to attain effective model calibration and rigorous uncertainty assessment by integrating environmental mathematical modeling with Bayesian analysis. We use a complex aquatic biogeochemical model that simulates multiple elemental cycles (org. C, N, P, Si, O), multiple functional phytoplankton (diatoms, green algae and cyanobacteria) and zooplankton (copepods and cladocerans) groups. The Bayesian calibration framework is illustrated using three synthetic datasets that represent oligo-, meso- and eutrophic lake conditions. Scientific knowledge, expert judgment, and observational data were used to formulate prior probability distributions and characterize the uncertainty pertaining to a subset of the model parameters, i.e., a vector comprising the 35 most influential parameters based on an earlier sensitivity analysis of the model. Our study also underscores the lack of perfect simulators of natural system dynamics using a statistical formulation that explicitly accounts for the discrepancy between mathematical models and environmental systems. The model reproduces the key epilimnetic temporal patterns and provides realistic estimates of predictive uncertainty for water quality variables of environmental management interest. Our analysis also demonstrates how the Bayesian parameter estimation can be used for assessing the exceedance frequency and confidence of compliance of different water quality criteria. The proposed methodological framework can be very useful in the policy-making process and can facilitate environmental management decisions in the Laurentian Great Lakes region.

Validation of an ecosystem modelling approach as a tool for ecological effect assessments

In ecotoxicology, derivation of a “safe” environmental concentration is usually achieved by the use of extrapolation factors or by statistical extrapolation from a set of single species toxicity data. These approaches ignore ecological interactions between species in the field. An ecology-based alternative to this pragmatic approach can be ecosystem modelling, which can account for ecological interactions. However, it is largely unexplored how well the predictions of these models quantitatively agree with large-scale experimental studies. Therefore, we evaluated the capacity of a flexible ecosystem model to predict population and ecosystem-level no observed effect concentrations (NOECs) of 7 organic toxicants. These NOECs were compared with population and ecosystem-NOECs observed in 11 micro- and mesocosm studies. For each of the latter studies, the model was customized to account for the specific ecological interactions within these systems and combined with appropriate single-species toxicity data from literature. Population-NOEC predictions were accurate, or at least protective, for 60, and 85% of all considered model populations, respectively. For all 11 studies, a protective ecosystem-NOEC could be derived, being accurate in 7 cases, and conservative in 4 cases. In general, it can be stated that this type of models can serve as an ecology-based alternative to current extrapolation techniques in EEAs and water quality standard setting.

Comparison of different toxic effect sub-models in ecosystem modelling used for ecological effect assessments and water quality standard setting

Ecosystem models, combining a food web model with a toxic effect sub-model, have been proposed to incorporate ecological interactions in ecological effect assessments. Toxic effect sub-models in different studies tend to differ in (1) the used single-species toxicity data, (2) the effects they consider, (3) the concentration–effect function used. In this paper, we constructed four ecosystem models, each with a different toxic effect sub-model, and tested their capacity to predict biomass changes, and no observed effect concentrations (NOECs) established in an experimental microcosm. For most populations, these predictions depended heavily on the type of ecosystem model. The ecosystem model with a toxic effect sub-model incorporating mortality effects using a logistic concentration–effect function made accurate predictions for most populations. Additional incorporation of sub-lethal effects did not result in better predictions. Ecosystem models using linear concentration–effect functions predict biomass decreases at concentrations that are four times lower than the observed NOECs.

Implications of Applying Statistically Based Procedures for Water Quality Assessment

Assessment of water quality conditions as required by Section 303d of the Clean Water Act must rely on limited monitoring data. Because data are limited there will always be the potential for error when deciding if water quality standards are being met. However, the informed use of statistical procedures makes it possible to describe and manage these errors. We make the case for using such procedures in water quality assessment and draw the implications for the monitoring data for water quality standard setting, arguing that standard setting must accommodate the limits of the monitoring data and the statistical procedures that will be used for water quality assessment.

Integrating Water Quality Standard Setting with Adaptive Implementation of TMDL Plans

Integrating Water Quality Standard Setting with Adaptive Implementation of TMDL Plans