Quality Index Method Research Articles

Application of groundwater quality index (GWQI) and GIS in groundwater quality zoing in Pleistocene aquifer in Phu My town, Ba Ria – Vung Tau province

Pleistocene aquifer is exploited for many purposes, including irrigation, domestic, production, and livestock use in Phu My town, Ba Ria – Vung Tau province. Groundwater Quality Index (GWQI) method combined with Geographic Information System (GIS) foundation is applied to determine the spatial variation as well as the suitability of groundwater in the study area. Water quality parameters in this study include pH, TDS, total hardness, Cl-, F-, NH4+, NO3-, SO42-, Pb2+, and Fe2+ were selected for analyzing from 17 monitoring wells in dry and wet seasons in 2017. The results indicate that water quality parameters such as Cl-, F-, NH4+-N, Pb2+ và Fe2+ exceed the maximum allowable levels by National Technical Regulation on Groundwater Quality. The groundwater quality, according to GWQI analysis results, shows that indicate 88% and 94% of the monitoring wells are from “good” to “excellent” type in the dry and wet seasons, respectively. The number of wells that have water quality from “poor” to “water unsuitable for drinking purpose” varies between the dry and wet seasons. Corresponding with the GWQI map, it shows that the area with good quality groundwater accounts for 98% of the total study area (331.44 km2) in the dry season and 94.5% of the study area (319.58 km2) in the wet season.

Revealing drinking water quality issues and possible health risks based on water quality index (WQI) method in the Shanmuganadhi River basin of South India.

The aim of the study is to address the issues and associated health risks due to consumption of high-fluoride water supplied for drinking in a rural part of Shanmuganadhi River basin, Tamil Nadu, India. In this study, 61 groundwater samples were gathered from various tube and open wells and analysed for fluoride and other physicochemical parameters. The abundance of cations is Na+ > Ca2+ > Mg2+ > K+, and that of anions is HCO3- > SO42- > Cl- > F-. The fluoride concentration in drinking groundwater varied from 0.10 to 3.3mg/l. According to the WHO standards, about 26% of the samples were unfit for drinking requirements (16 out of 61 samples) Water quality index (WQI) method was adopted to categorize the water into different classes to understand its suitability for drinking requirements. WQI signified that nearly 52% of the samples denoted poor, very poor and not suitable categories, whereas 48% of samples denoted good and excellent categories for consumption. Health risks associated with high-fluoride drinking water were assessed for various age groups of inhabitants such as children, teens and adults. The hazard quotient estimated based on the oral intake ranged from 0.00E+00 to 5.50E+00, from 0.00E+00 to 4.22E+00 and from 0.00E+00 to 3.45E+00 for children, teens and adults, respectively. It suggested that the health risks are associated with 75%, 59% and 43% of samples, respectively, among children, teens and adults. Therefore, children are more inclined towards risk than teens and adults in this region based on the intake of fluoride-rich drinking water. To improve the present scenario, groundwater should be either treated before drinking water supply or must be artificially recharged to lower the concentration of ions.

Shelf‐life determination: inter‐relationship among chemical quality indicators of black tiger shrimp under different preservation conditions

AbstractIn this current work, the post‐harvest freshness and quality of black tiger shrimp as affected by different preservation methods during 14 days of storage at 0 °C were investigated. Especially, the different preservation methods included immersing in polyphenols solution, vacuum packaging, and a combination of polyphenol solutions and vacuum packaging, which were all compared with the control method, i.e. storage in ice. The quality indicators including total volatile basic nitrogen (TVB‐N), trimethylamine (TMA‐N), histamine, hypoxanthine, and quality index (QI) were used to evaluate the quality changes of shrimp during storage. The results showed that TVB‐N, TMA‐N and histamine increased with the increasing of storage time but at two different stages, while QI and hypoxanthine content increased linearly with preservation time. The process of black spot formation was partly and almost completely inhibited when shrimps were treated with polyphenol solution and stored under vacuum conditions. Linear regression equations between biochemical quality indicators have been developed for each sample. The remaining shelf‐life can be estimated by quality index method (QIM). The shelf‐life of treated samples appeared longer than that of the control. The vacuum packaging combined with polyphenol solutions of this study has a promise to increase the shelf‐life and quality of shrimp.

Assessment of Groundwater Quality for Different Aquifers in Halaib and Shalatien Area at South Eastern Desert of Egypt تقییم جودة المیاه الجوفیة للخزانات الصخریة الجوفیة المختلفة فى منطقة حلایب وشلاتین جنوب الصحراء الشرقیة – مصر

This work aims at assessing the groundwater quality in Halaib and Shalatien area, the main water resource for irrigation and civic utilization is groundwater (springs and wells). The groundwater aquifers in this area could be classified into three aquifer systems according to their litho-stratigraphic as follows: Fractured basement aquifer system, Nubian sandstone aquifer system and Quaternary aquifer system. 13 samples from different aquifer systems were taken in the study area; four samples were taken from groundwaters of fractured basement aquifer, eight from the Nubian sandstone aquifer and one from the Quaternary aquifer. Assessment in terms of salinity and sodicity hazards according to USDA (1954). Evaluation of groundwater quality using irrigation water quality index (IWQI) method was established by Meireles et al. (2010) for agricultural purposes with help of the Geographic Information System (GIS) technique. Five chemical parameters were utilized to calculate the IWQI including EC, Na+, Cl-, HCO3- and SAR. The IWQI map results showed that 46.2 % of the samples classified as low restricted are suitable for irrigation directly without any processing, 23.1% of the samples classified as moderate to highly restricted and can be used only in soils with high permeability values, recommended leaching of salts to avoid soil degradation. The remaining (30.7%) of the studied samples classified as severe restricted are suitable only for soils that have high permeability values applied the excess of water for leaching to avoid the accumulation of salt. In brief, these samples should be avoided its use for irrigation under normal conditions.

Chemometric appraisal of groundwater quality for domestic, irrigation and industrial purposes in Lower Bhavani River basin, Tamil Nadu, India

ABSTRACT Groundwater quality in the Lower Bhavani River basin has been evaluated for drinking, irrigation and industrial purposes. To study drinking water quality, the Water Quality Index (WQI) method was applied along with classic hydrochemical methods, and the results then compared with World Health Organisation (WHO) standards. TDS and other ionic constituents showed that 66% of the samples were good qualityfor drinking water. These results are compatible with the WQI results, which showed 64% of the samples were excellent or good quality. High values of WQI are associated with elevated fluoride and nitrate concentration. A spatial variation map shows that the southern region of the basin havelower quality water compared to the central region. Both natural and anthropogenic activities, such as industrial effluents, agricultural fertilisers etc., influence the groundwater quality. Analysis of groundwater quality for irrigation purposes shows that the water is prone to have a medium to high salinity hazard. While the sodium absorption ratio (SAR) of the groundwater shows that 98% of the samples are excellent for irrigation and the permeability index (PI) shows that 63% of the samples are excellent for irrigation, on the other hand, the water is unfit in around 55% of samples in terms of magnesium hazard (MH) and Kellys index (KI) because a higher than normal concentration of Mg, Ca and K is observed. In the water quality parameters for industrial purposes, Langelier Index (LI) and Aggressive Index (AI)showed significant scaling tendency. In contrast to this, Puckorius Index (PI), Ryznar Stability Index (RI) and Larson-Skold Index (LS) indicate that the water samples have significant corrosion tendencies.Routine monitoring of water quality is suggested in the regions where groundwater quality issues are reported in this study.

Water quality evaluation based on the water quality index method in Honghu Lake: one of the largest shallow lakes in the Yangtze River Economic Zone

Abstract Honghu Lake is the largest lake-type wetland in Hubei Province, China. It is also one of the largest shallow lakes in the Yangtze River Economic Zone, a key area in the relatively more developed southeast of China. However, the water quality has seen a deterioration tendency in recent decades, mostly owing to unreasonable human activities such as lake enclosure aquaculture following rapid social and economic development. Based on the water quality index (WQI) method, the water quality of Honghu Lake, by the vast amount of data collected from five observation sites monitored over ten years, was analyzed and evaluated. The results show that: (i) the water quality of Honghu Lake is in the ‘General’ grade as a whole with a WQI value of 43.41 ± 6.66; (ii) the water quality has been improving in the recent two years, reversing its decade-long deterioration; (iii) the water quality sampled at the Lantian site is the worst while that of the Guandun site is the best; (iv) the concentration of Pb and Cd are the key parameters to determine the water quality of Honghu Lake. Therefore, it can be concluded that more attention should be paid to investigate heavy metals in Honghu Lake in the future.

Succession Characteristics of Algae Functional Groups and Water Quality Assessment in a Drinking Water Reservoir

To understand the temporal and spatial succession characteristics of algae functional communities and water quality changes in a drinking water reservoir, the Lijiahe Reservoir was selected to monitor variations in water quality and algae from September 2018 to June 2019. The algae community was classified into functional groups following the method proposed by Reynolds and Padisák. The relationship between algal functional community and water quality was discussed, and the water quality was assessed using the water quality index (WQI) method. The results showed that 56 species of algae were obtained, belonging to 4 families and 28 genera, which were divided into 15 functional groups. The dominant algae functional communities were B, D, G, J, L0, Mp, P, W1, and X1. The algae structure of Lijiahe Reservoir showed obvious seasonal characteristics. The algal density in the mixed period was significantly lower than that in the stratification period. The main functional algae in the mixed period were Chlorella and Cyclotella, but Navicula and Synedra were the dominant functional algae in the stratification period. Redundancy analysis showed that the water temperature, mixing depth, and relative water column stability index were the main factors driving algae succession. WQI analysis indicated that the water quality of Lijiahe Reservoir was "good", and the water quality during the mixed period was slightly better than that in the stratification period. This study demonstrates that water-lifting aerators can change the succession characteristics of algae functional groups, and effectively contribute to improvement in water quality in a drinking water reservoir.

Evaluation of groundwater and surface water quality suitability for drinking and agricultural purposes in Kombolcha town area, eastern Amhara region, Ethiopia

The appropriateness of groundwater and surface water for domestic and agricultural uses was assessed in Kombolcha town located in Amhara region using water quality indexes. The town is one of the fast developing and emerging as a leading industrial town in Ethiopia and is selected as an industrial zone by the government. A total of eighteen groundwater and five surface water samples were collected using 250-ml sampling bottles at selected points and analyzed for major ions (Ca2+, Mg2+, Na+, K+, HCO3−, SO42−, Cl−) in the dry season (May 2017) and wet season (Nov, 2017). A water quality index (WQI) method was applied to evaluate the suitability of the groundwater for drinking purposes using eighteen groundwater sampling points and fourteen parameters (EC, TDS, HCO3−, Ca2+, Mg2+, Na+, K+, Cl, SO42−, NO3−, PO43−, Cu, Fe and F−), and each parameters were also compared with WHO drinking guidelines. According to WQI, groundwater samples of the present study show excellent (72.2%) and good (27.8%) in the dry season and excellent (83.3%) and good (16.7%) in the wet season. Assessment of groundwater samples from Na+, Mg2+, K+, Cl−, SO42−, HCO3−, NO3−, PO43−, F− and Cu parameters indicates that groundwater of the study area is chemically suitable for drinking purposes. However, some are unsuitable according to the EC, TDS and Ca2+ and all are not suitable with reference to iron (Fe). Groundwater and surface water quality for irrigation were evaluated using SAR, RSC, MR, PI, KI and EC. The results show that most of the groundwater and surface water samples were suitable/excellent for irrigation with some places in the study locations that belong to the good and permissible. The sodium hazard versus salinity hazard of the entire water sample collected in two seasons falls into category C2-S1 and C3-S1, indicating low alkali hazards and excellent irrigation water. Groundwater samples in wet seasons are more suitable than in the dry season for drinking and irrigation purposes, and groundwater samples are less polluted than surface water. The main source of pollution in the study area is the effluents from industries.

Quality improvement education for medical students: a near-peer pilot study

BackgroundQuality improvement (QI) is an essential component of modern clinical practice. Front-line professionals offer valuable perspectives on areas for improvement and are motivated to deliver change. In the UK, all junior doctors are expected to participate in QI in order to advance to the next stage of their training. However, UK undergraduates receive no standardized training in QI methods. This is perpetuated within medical schools by a lack of teaching capacity and competing priorities, and may lead to tokenistic engagement with future QI projects.MethodsWe describe a near-peer teaching programme designed to introduce students to QI methods. This pilot study was conceived and delivered in full by junior doctors and used existing resources to ensure high quality teaching content. 111 fifth-year medical students from the University of Cambridge were taught in interactive, participative workshops that encourage them to develop their own QI change ideas and projects. Core topics included the model for improvement, driver diagrams, stakeholder engagement, measurement for improvement and analysing and presenting data. Students completed surveys before and immediately after this intervention to assess their understanding of and confidence in utilizing QI methods. Questionnaires were also completed by junior doctor tutors.ResultsAnalysis of questionnaires completed before and immediately after the intervention revealed statistically significant improvements in students’ self-reported understanding of QI (p < 0.05) and confidence in applying techniques to their own work (p < 0.05). Students expressed a preference for QI teaching delivered by junior doctors, citing a relaxed learning environment and greater relevance to their stage of training. Tutors reported increased confidence in using QI techniques and a greater willingness to engage with QI in future.ConclusionsIn this single-centre study, near-peer teaching produced significant improvements in students’ self-reported understanding of QI and confidence in applying QI methods. Near-peer teaching may constitute a sustainable means of teaching essential QI skills at undergraduate level. Future work must evaluate objective measures of student engagement with and competence in conducting QI.

Evaluation of water quality in the South-to-North Water Diversion Project of China using the water quality index (WQI) method

The world’s longest trans-basin water diversion project, the Middle-Route (MR) of the South-to-North Water Diversion Project of China (SNWDPC), has officially been in operation for over 5 years since December 2014. Its water quality status has always attracted special attention because it is related to the health and safety of more than 58 million people and the integrity of an ecosystem covering more than 155,000 km2. This study presented and analysed the spatio-temporal variations and trends of 16 water quality parameters, including pH, water temperature (WT), dissolved oxygen (DO), permanganate index (PI), five-day biochemical oxygen demand (BOD5), fecal coliform (F. coli), total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH3−N), sulphate (SO42−), fluoride (F−), mercury (Hg), arsenic (As), selenium (Se), copper (Cu), and zinc (Zn), which were determined monthly from samples collected at 27 water quality monitoring stations in the MR of the SNWDPC from March 2016 to February 2019. The water quality index (WQI) was used to evaluate the seasonal and spatial water quality changes during the monitoring period, and a new WQImin model consisting of five crucial parameters, i.e., TP, F. coli, Hg, WT, and DO, was built by using stepwise multiple linear regression analysis. The results demonstrated that the water quality status of the MR of the SNWDPC has been steadily maintained at an “excellent” level during the monitoring period, with an overall average WQI value of 90.39 and twelve seasonal mean WQI values ranging from 87.67 to 91.82. The proposed WQImin model that uses the selected five key parameters and the weights of those parameters has exhibited excellent performance in the water quality assessment of the project, with the coefficient of determination (R2), Root Mean Square Error (RMSE), and Percentage Error (PE) values of 0.901, 2.21, 1.93%, respectively, showing that the proposed WQImin model is a useful and efficient tool to evaluate and manage the water quality. For the management department, the risk sources near certain stations with abnormally high values should be carefully inspected and strictly managed to maintain excellent water quality. The potential risks of algae proliferation in this project should be of concern in future research.

Assessment of Lower Zab river water quality using both Canadian Water Quality Index Method and NSF Water Quality Index Method

Rivers are considered the most important sources of surface water on Earth. They are play a significant role in all human activities and the quality of river water is needed. Therefore, the importance of the water quality index is arising through providing data base about quality of the water source, and explain the change in the water quality over a period of time continually. This study involved determination of physicochemical and biological parameters of Lower Zab river in Kirkuk city at two different points. The objectives of the study are to assess the present water quality, through analysis of some selected water quality parameters like pH, TDS, BOD, dissolved oxygen, turbidity, EC, alkalinity, and salinity etc. and to compare the results with the Canadian Council of Ministers of the Environment and National Sanitation Foundation Water Quality Indices. Raw water samples were collected from the Lower Zab river twice a month by one sample every 15 days from each station. The water quality data include 16 different parameters. Tests were carried out following the American Public Health Association standard methods. The results show that all parameters values were within the standards of drinking water proposed by the CCME standards and Iraqi standards or the World Health Organization standards for drinking purpose, except turbidity, DO, nitrate, calcium, which were mostly higher than the standards and sometimes BOD and potassium. The results of WQI showed that the water quality at LZ3 station is lower than LZ2 station due to the polluting activity of the Lower Zab river. Furthermore, for the years 2014, 2015, and 2016, the water quality was degraded due to the ISIS war. Also, it was noted in the 2013 year that the water quality degraded more in fall and winter seasons due to that the earth has exposed to the long-dried season and then suddenly exposed to a high rainfall season which in turns leads to increase some parameters very high (i.e. turbidity). Finally, the Lower Zab river water cannot be use for drinking directly. However, a pretreatment is needed before the drinking use.

Assessment of urban river water quality and developing strategies for phosphate removal from water and wastewaters: Integrated monitoring and mitigation studies

In this work, the water quality status of the surface water that lies around the Karamana River basin, Trivandrum urban area, was studied on the basis of the water quality index (WQI) method. The eutrophic condition of the basin is revealed, and proper mitigation strategy was adopted for the removal of phosphate species using pillared clay materials. Proper sampling was carried out in the urban rivers, and various physico-chemical parameters for evaluating the quality of water were analysed. WQI values obtained for these riverine systems are in the range 317.7–3005.1, indicating that the water is not suitable without treatment for any domestic activities. Also, phosphate ions in the range 1.98–20.52 mg/L reflect the dominance of phosphate species in surface water. A proper mitigation strategy was adopted for the selective removal of phosphate ions using adsorption technique by using zirconium-pillared bentonite clay (ZPBC) prepared by the stirring–ageing technique. The batch adsorption experiment performed on simulated phosphate solution shows that for 2.0 g/L of ZPBC a maximum phosphate adsorption capacity of 35.71 mg/g was achieved in 30 min at pH 3.0. The data obtained were used to study models in kinetics and isotherm. The reusability of spent ZPBC for five continuous cycles without major loss in adsorption capacity using 0.025 M Na2CO3 extractant was proved from the desorption study. A single-stage reactor was also designed from the isotherm data and proved to be effective. The applicability of the adsorbent towards phosphate anions was successfully checked in the laboratory using surface water collected and found that the complete removal of phosphate was achieved using 6.0, 8.0 and 10.0 g/L of ZPBC.

Evaluating the Efficacy of Point-of-Use Water Treatment Systems Using the Water Quality Index in Rural Southwest China

Rural China faces a shortage of safe drinking water. There are significant challenges associated with small centralized water supply systems and decentralized water supply systems. Many rural residents use point-of-use water treatment systems to ensure the safety of their drinking water. The actual water purification effect and applicability of these water treatment systems in small centralized and decentralized water supply systems need to be determined urgently. In this study, the water quality index (WQI) method was applied for the first time in rural areas to evaluate the effectiveness of point-of-use water treatment systems. A total of 67 reverse osmosis water treatment systems were tested. The rate of compliance with drinking water standards of the decentralized water supply was low (37%). Compared with untreated water, the use of a reverse osmosis water treatment system improved the rate of compliance with drinking water standards, but this effect was not satisfactory (8%). Among the factors potentially affecting the purified water quality of point-of-use water treatment systems (e.g., service time of the water treatment system, service time of the filter element, and type of water source), the service time of the filter element had the most significant influence on the water quality. If the filter element had not been replaced for a long period, the removal effect of the water treatment system on the total hardness, sulfide, copper, and ammonia nitrogen was significantly affected, reducing the quality of the purified water. To ensure the safety of drinking water, it is recommended to replace the filter element of a reverse osmosis water treatment system at least once a year.

Assessing fidelity to evidence-based quality improvement as an implementation strategy for patient-centered medical home transformation in the Veterans Health Administration

BackgroundEffective implementation strategies might facilitate patient-centered medical home (PCMH) uptake and spread by targeting barriers to change. Evidence-based quality improvement (EBQI) is a multi-faceted implementation strategy that is based on a clinical-researcher partnership. It promotes organizational change by fostering innovation and the spread of those innovations that are successful. Previous studies demonstrated that EBQI accelerated PCMH adoption within Veterans Health Administration primary care practices, compared with standard PCMH implementation. Research to date has not documented fidelity to the EBQI implementation strategy, limiting usefulness of prior research findings. This paper develops and assesses clinical participants’ fidelity to three core EBQI elements for PCMH (EBQI-PCMH), explores the relationship between fidelity and successful QI project completion and spread (the outcome of EBQI-PCMH), and assesses the role of the clinical-researcher partnership in achieving EBQI-PCMH fidelity.MethodsNine primary care practice sites and seven across-sites, topic-focused workgroups participated (2010–2014). Core EBQI elements included leadership-frontlines priority-setting for QI, ongoing access to technical expertise, coaching, and mentoring in QI methods (through a QI collaborative), and data/evidence use to inform QI. We used explicit criteria to measure and assess EBQI-PCMH fidelity across clinical participants. We mapped fidelity to evaluation data on implementation and spread of successful QI projects/products. To assess the clinical-researcher partnership role in EBQI-PCMH, we analyzed 73 key stakeholder interviews using thematic analysis.ResultsSeven of 9 sites and 3 of 7 workgroups achieved high or medium fidelity to leadership-frontlines priority-setting. Fidelity was mixed for ongoing technical expertise and data/evidence use. Longer duration in EBQI-PCMH and higher fidelity to priority-setting and ongoing technical expertise appear correlated with successful QI project completion and spread. According to key stakeholders, partnership with researchers, as well as bi-directional communication between leaders and QI teams and project management/data support were critical to achieving EBQI-PCMH fidelity.ConclusionsThis study advances implementation theory and research by developing measures for and assessing fidelity to core EBQI elements in relationship to completion and spread of QI innovation projects or tools for addressing PCMH challenges. These results help close the gap between EBQI elements, their intended outcome, and the finding that EBQI-PCMH resulted in accelerated adoption of PCMH.

Water quality analysis of Saluran Tarum Barat, West Java, based on National Sanitation Foundation-Water Quality Index (NSF-WQI)

The Saluran Tarum Barat, which is 68.74 kilometers long, starts in Klari, Karawang, West Java, and ends in Cawang, East Jakarta. The Saluran Tarum Barat runs alongside human activities and various environmental conditions. The initial part of the Saluran Tarum Barat is surrounded by agricultural activities, the central part by industrial activities, and the final part by infrastructure development activities. Those various activities and environmental conditions may have different effects on the water quality of the Saluran Tarum Barat. The purpose of this research is to ascertainthe water quality of the Saluran Tarum Barat based on physical, chemical, and biological parameters determined through the National Sanitation Foundation-Water Quality Index (NSF-WQI) method. The results showed that the water quality is classified in the medium category, with a value range of 55.06–67.92.

Study on eutrophication characteristics of rainy and dry season in Shenzhen Bay

Firstly, the eutrophication of five monitoring points in Shenzhen Bay was analyzed by using the nutritional status quality index method, and the eutrophication of the entire Shenzhen Bay was analyzed by the results of the eutrophication model simulation. The results showed that the maximum of the nutritional status quality index(NQI) in the dry season was 22, the minimum was 3;the maximum NQI in the rainy season was 23, the minimum was 4, and when NQI is greater than 3, the water is eutrophication level, so whether it was the dry season or the rainy season, Shenzhen Bay is basically eutrophic, and the eutrophication of the Shenzhen Bay in the rainy season is more serious than that in the dry season. Regardless of the dry season or the rainy season, the NQI of the Shenzhen Bay outer area is basically around 5, while the NQI of the interior area is basically larger than that of the outer area. The degree of eutrophication is more serious than that of the outer area;the maximum NQI is 22 in the high tide during the dry season, and the maximum NQI is 23 in the rainy season;the maximum NQI is 21 in the ebb during the dry season, and the maximum NQI in the rainy season is 22, so the eutrophication of Shenzhen Bay is more serious than the ebb when the high tide.

Water quality assessment using comprehensive water quality index and modified Nemerow index method: A case study of Jinghui Canal, North China

Groundwater is an essential part of water resources for human survival in irrigation regions. In this study, water quality of jinghui canal irrigation area were assessed using the comprehensive water quality index method (CWQI), normal Nemerow index assessment method (NNI) and modified Nemerow index assessment method (MNI). 47 groundwater samples were collected from unconfined aquifers through shallow well during November 2009. The results showed that groundwater quality in the area was poor due to the industrial and agricultural activities. Most of the groundwater samples were identified as Grade IV and Grade V by the comprehensive water quality index method. While majority of groundwater samples were assessed as Grade IV by both NNI and MNI. Besides, the water quality assessed by MNI was better than NNI and NNI was better than CWQI, which was caused by parameter value and weight value, so we should not only stick to a certain assessment method, but also need to comprehensively consider the purpose of evaluation.

Determination of Some Physico-Chemical Parameters and Water Quality Index (WQI) of Laguna de Bay, Philippines

Water quality monitoring activities is a vital part in assessing the status of certain bodies of water such as the Laguna de Bay. The lake has been a significant natural resource as a catchment of an expansive watershed providing various ecological and economic values. It is the largest inland water body in the Philippines and the third largest in South East Asia. Water quality monitoring network is a critical element in the assessment, restoration and protection of Laguna de Bay. This paper measured some important physico-chemical properties of four selected sites from Laguna de Bay such as temperature, pH, electrical conductivity, alkalinity, dissolved oxygen levels, and phosphate and ammonia concentrations. Water Quality Index (WQI) utilizing Weighted Arithmetic Water Quality Index Method was also evaluated.

Quality Index Method (QIM) Scheme Developed for Whole Nile Tilapias (Oreochromis niloticus) Ice Stored under Refrigeration and Correlation with Physicochemical and Microbiological Quality Parameters

ABSTRACT A quality index method (QIM) scheme was optimized to evaluate the freshness of whole tilapias (Oreochromis niloticus) ice stored under refrigerated conditions, which is the most common format of commercialization between primary producers and retailers. QI showed a high prediction accuracy, estimating a rejection point of 10.8 days. Principal component analysis showed the influence of the storage time on sensory, physicochemical (instrumental color and texture profile, total volatile base nitrogen, thiobarbituric acid-reactive substances, pH), and microbiological (total aerobic mesophilic count and total aerobic psychrotrophic count) quality parameters and the correlations between them. The suitability of the QIM scheme for assessing the freshness of whole tilapia was demonstrated to be a fast and accurate tool to maintain proper quality control along the production chain.

Water Quality Index Response of UI Cascade-Pond System on Catchment Imperviousness Temporal Variation

This study focuses on the water quality in a catchment area that is affected by the imperviousness cover. The purpose of this study is to prove the correlation analysis between impervious cover as the independent variable and the water quality index as the dependent variable by analysing the correlation and regression relationship. The study area is located in the catchment area at the campus of Universitas Indonesia, Depok, West Java. The data of the imperviousness is collected from the digital globe imagery and digitized based on identified rooftops. The water quality data is determined based on previous reports and collected manually in the pond by the author. The water collected from the pond will be put for laboratory test to be able to get the quality of the sample according to the determined parameters and then knowing the quality of the pond using the National Sanitation’s Foundation Water Quality Index (NSF-WQI) method. The targeted water quality index is determined based on water usage suitability referring to the Indonesian government regulation number 82/2001. As time goes by, the impervious cover grows and gives an effect to the water quality of the UI cascade-pond. As a tool to set a plan for future development on the catchment area of the pond system in Universitas Indonesia, it is possible to use the linear relationship between catchment area imperviousness and water quality index. After doing a linear regression analysis between imperviousness and water quality, a relationship was found that the change of impervious cover has an effect towards the water quality and is getting worse over time.