Water Contamination Levels Research Articles

English

This study was to investigate the contamination level of waste water in the Kushtia industrial region of Bangladesh. Some parameters of waste water were analyzed like pH, electrical conductance, total dissolved solids (TDS), hardness, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and for heavy metal (Pb, Cd, Cr, Cu, Mn) concentration. The pH was found to be of range from 8.485 to 4.187; whereas, the electrical conductance was 8.4×10-4 to 2.9×10-3 ohm-1cm-1. In addition, the lowest value of TDS was 567 and the highest was 956 ppm. Furthermore, the hardness was 848 to 485 mg/l as CaCO3. Besides, at 20°C, the BOD values were evaluated from 57 to 88 ppm. The COD values retained were from 150 to 108 ppm. In contrast, heavy metals (Pb, Cd, Cr, Cu and Mn) were analyzed and compared with standards of drinking water. The results indicate that the concentration of Mn (0.68 to 0.72 ppm) exceeded the standards, although Pb and Cu were found within the standard limit at 0.0045 to 0.0085 and 1.33 to 1.58 ppm, respectively. Interestingly, contamination of Cd and Cr identified were below detective level. This study points out the health risk status of waste water for residents and aquatic living being, an ultimate concern for their survival in the region.   Key words: Waste water, pollution assessment, physico-chemical parameters, atomic absorption spectrophotometer (AAS), heavy metal contamination.

Arsenite exposure accelerates aging process regulated by the transcription factor DAF-16/FOXO in Caenorhabditis elegans

Arsenic is a known human carcinogen and high levels of arsenic contamination in food, soils, water, and air are of toxicology concerns. Nowadays, arsenic is still a contaminant of emerging interest, yet the effects of arsenic on aging process have received little attention. In this study, we investigated the effects and the underlying mechanisms of chronic arsenite exposure on the aging process in Caenorhabditis elegans. The results showed that prolonged arsenite exposure caused significantly decreased lifespan compared to non-exposed ones. In addition, arsenite exposure (100 μM) caused significant changes of age-dependent biomarkers, including a decrease of defecation frequency, accumulations of intestinal lipofuscin and lipid peroxidation in an age-dependent manner in C. elegans. Further evidence revealed that intracellular reactive oxygen species (ROS) level was significantly increased in an age-dependent manner upon 100 μM arsenite exposure. Moreover, the mRNA levels of transcriptional makers of aging (hsp-16.1, hsp-16.49, and hsp-70) were increased in aged worms under arsenite exposure (100 μM). Finally, we showed that daf-16 mutant worms were more sensitive to arsenite exposure (100 μM) on lifespan and failed to induce the expression of its target gene sod-3 in aged daf-16 mutant under arsenite exposure (100 μM). Our study demonstrated that chronic arsenite exposure resulted in accelerated aging process in C. elegans. The overproduction of intracellular ROS and the transcription factor DAF-16/FOXO play roles in mediating the accelerated aging process by arsenite exposure in C. elegans. This study implicates a potential ecotoxicological and health risk of arsenic in the environment.

The Contamination Levels of Water and Sediment from Lake Togo by the Persistent Organic Pollutants (Pops)

This study was carried out to evaluate the contamination severity of Lake Togo by organochlorinated pesticides historically used in agriculture and in health programs against disease vectors in public health. A total of 48 samples of sediments and 48 samples of water were seasonally collected. For both sediment and water 3 samples per site were collected at 8 sites in the 2014 rainy season and in the 2015 dry season. Water samples were processed using a liquid-liquid method solvent extraction while Soxhlet extraction was used for sediment samples. The sediment and water extractions were cleaned-up and qualitative-quantitative analysis performed on gas chromatograph equipped with electron capture detector (GC-ECD). Pesticides residue levels in water ranged from < 0.001 to 0.093±0.20 µg l-1 (lindane) in rainy season and from < 0.001 to 0.352±0.07 µg l-1 (dieldrin) in dry season. They were lower than that found in sediment which ranged from < 0.001 to 0.98±0.18 µg kg-1 dry weight (pp′-DDE) in rainy season and from < 0.001 to 2.19±0.31 µg kg-1 dry weight (heptachlor epoxide) in dry season. The concentrations of the organochlorinated residues in water and sediment were higher during the dry season. Except pp′-DDE, pp′-DDD, heptachlor and heptachlor epoxide, the others pesticide residues concentrations detected in water samples in dry season were above the maximum acceptable concentration of 0.1 µg l-1 for individual pesticides set by the European Union (EU) for the protection of human health. Pesticide contamination level of Lake Togo is therefore, likely to be harmful to human health in dry season.

Pesticides in Brazilian freshwaters: a critical review.

The widespread use of pesticides in agriculture can lead to water contamination and cause adverse effects on non-target organisms. Brazil has been the world's top pesticide market consumer since 2008, with 381 approved pesticides for crop use. This study provides a comprehensive literature review on the occurrence of pesticide residues in Brazilian freshwaters. We searched for information in official agency records and peer-reviewed scientific literature. Risk quotients were calculated to assess the potential risk posed to aquatic life by the individual pesticides based on their levels of water contamination. Studies about the occurrence of pesticides in freshwaters in Brazil are scarce and concentrated in few sampling sites in 5 of the 27 states. Herbicides (21) accounted for the majority of the substances investigated, followed by fungicides (11), insecticides (10) and plant growth regulators (1). Insecticides are the class of major concern. Brazil would benefit from the implementation of a nationwide pesticide freshwater monitoring program to support preventive, remediation and enforcement actions.

The importance of integrated solutions to flooding and water quality problems in the tropical megacity of Jakarta

Rapid urbanisation is transforming many urban rivers by affecting their hydraulic conditions and water quality. This process is particularly intense in some areas of the planet, where migratory phenomena and the associated urbanisation pace and conurbation are extreme. In these cases, the lack of water supply and sewerage infrastructures can lead to enormous pressure on urban river corridors, which often implies irreversible pollution of surface waters and shallow aquifers. In this article we address the problem of how integrated planning of urban river corridor management is essential to achieve sustainable solutions and how modern simulation tools can contribute to this effect. This is done by reporting about an exemplary case study, the Ciliwung River flowing through Jakarta, which is highly polluted and floods frequently large areas of the city. Indonesian authorities’ highest priority is to reduce the flood problem but without a clear integrated rehabilitation strategy that accounts for water quality issues. Through field campaigns and model simulations we demonstrate how measures to solve the flood problem can further deplete water quality if the pollution load is not reduced. Results suggest that the current hydraulic river regime produces a benefit for the river health by increasing oxygen levels, natural degradation processes and dilution. A reduction in the average discharge by means of dam construction, as currently considered by the authorities, is likely to increase contamination levels of surface water and shallow aquifer, which is recharged by the river.

치과용 유니트 수계의 미생물 오염 및 효과적인 관리 방법

Dental chair unit (DCU) is the most essential equipment for the dental treatment in dentistry. DCU output water is used for various applications during dental treatment. DCU output water must be clean at the same level as drinking water since patients and dental staff are regularly exposed to water and aerosols generated from the DCU. Many studies demonstrated that DCU output water is frequently contaminated with microorganisms including opportunistic pathogen such as Legionella and Pseudomonas species. Thus, DCU output water may be a potential source of infection. In order to reduce microbial contamination levels in DCU output water, periodic management and continuous disinfection are necessary. Currently, there are a variety of disinfection methods for managing DCU output water and its efficacy is also diverse. We reviewed the level of microbial contamination, clinical implications of contaminated DCU output water and the various DCU disinfection methods.

A Study on Finding the Contamination Levelin Water for Domestic Applications

Management and control of Water is a Complex multi-disciplinary task requiring the adequate approaches and techniques. Traditional modeling of physical process is often tries to explain the underlying processes. On this the so called Data-driven technique, borrowing heavily from artificial intelligence techniques, are based on limited knowledge of modeling process and relay on data describing the input and output characteristics. In this project application of widely used particular types of data driven models, namely artificial neural network(ANN) is used to model the water resource management field. Neural network has been successfully applied to wide range of problems covering the variety of sectors. During this ANN evolved from being only a research tool that is applied to many real world problems. Sensors play a vital role in detecting the impurities in water. However, in this project a wide range of wireless sensors are being operated in the water field, to detect the contamination level. In this project sensors namely PH, TURBIDITY, CONDUCTIVITY, HARDNESS and CALCIUM detection sensors are being employed.

Towards The Use of Probabilistic Spatial Relation Databases in Business Process Modeling

In this paper, the authors combine the methods of probabilistic databases, GIS (Geographical Information Systems) and business process modelling to evaluate the agricultural activities. The authors provide a technique to evaluate the risk of agricultural activities among the hydrological objects (lakes, rivers, etc.) and agricultural plots. The spatial relation is an important information needed in the evaluation processes. This type of information is usually uncertain and the available data are often not precise. Consequently, probabilistic database is used to capture the uncertainty of the spatial objects in order to estimate the level of possible water and soil contamination (by agricultural inputs). Probabilistic spatial relations provide information on the layout of spatial objects. Probabilities are stored in a probabilistic database. Probabilistic database is a finite number of complete databases that are assigned with a set of probabilities. Probabilistic data-aware business processes integrate the theory of probabilistic database with business processes modeling methods. This new formalism of business processes helps the experts to model the environmental risks in terms of probabilistic spatial relations.

A yeast co-culture-based biosensor for determination of waste water contamination levels

Artificial microbial co-cultures were formed to develop the receptor element of a biosensor for assessment of biological oxygen demand (BOD). The co-cultures possessed broad substrate specificities and enabled assays of water and fermentation products within a broad BOD range (2.4–80mg/dm3) with a high correlation to the standard method (R=0.9988). The use of the co-cultures of the yeasts Pichia angusta, Arxula adeninivorans and Debaryomyces hansenii immobilized in N-vinylpyrrolidone-modified poly(vinyl alcohol) enabled developing a BOD biosensor possessing the characteristics not inferior to those in the known biosensors. The results are indicative of a potential of using these co-cultures as the receptor element base in prototype models of instruments for broad application.

Assessment of surface water pollutant models of estuaries and coastal zone of Quang Ninh – Hai Phong using Spot-5 images

Abstract The coastal zone and estuaries of Quang Ninh and Hai Phong have great potential not only for economic development but also for protection and conservation of biodiversity and ecosystem. Nowadays, due to industrial, agricultural and anthropogenic activities signs of water pollution in the region have been found. The level of surface water pollution can be determined by traditional methods through observatory stations. However, a traditional approach to determine water contamination is discontinuous, and thereby makes pollution assessment of the entire estuary very difficult. Nowadays, remote sensing technology has been developed and widely applied in many fields, for instance, in monitoring water environments. Remote sensing data combined with information from in-situ observations allow for extraction of polluted components in water and accurate measurements of pollution level in the large regions ensuring objectivity. According to results obtained from Spot-5 imagery of Quang Ninh and Hai Phong, the extracted pollution components, like BOD, COD and TSS can be determined with the root mean square error, the absolute mean error and the absolute mean percentage error (%): ±4.37 (mg/l) 3.86 (mg/l), 27%; ±55.32 (mg/l), 48.30 (mg/l), 14%; and ±32.90 (mg/l), 23.38 (mg/l), 28%; respectively. Obtained outcomes guarantee objectivity in assessing water contaminant levels in the investigated regions and show the advantages of remote sensing applications in Resource and Environmental Monitoring in relation to Water – Air – Land.

Assessment of water quality in urban streams based on larvae of Hydropsyche angustipennis (Insecta, Trichoptera)

Hydropsyche angustipennis (Insecta, Trichoptera) larvae were used as indicators of stream contamination in the city of Łódź, Poland. The larvae of H. angustipennis were present at 9 sampling sites established for this study. Significant differences between the sampling sites were noted for environmental parameters as well as concentration of chemicals in water and biodiversity of aquatic invertebrates. Statistical analyses showed significant correlations between quantity and quality of water pollutants and density of H. angustipennis larvae, concentration of metals in larval bodies, and the appearance of morphological anomalies in tracheal gills and anal papillae. In comparison to literature data, the level of contaminants in water, including heavy metals, for each of the studied streams of Łódź was surprisingly low while concentration of these metals in the whole bodies of H. angustipennis larvae was very high. Some of the heavy metals present in the water might be identified only after conducting analyses of their concentration in the larval bodies. Therefore, long life cycle of H. angustipennis and heavy metal tolerance with a possibility of their accumulation in the larval bodies may constitute a support to traditional chemical assessment of water quality or traditional biomonitoring.

Comparison of radioactive cesium contamination of lake water, bottom sediment, plankton, and freshwater fish among lakes of Fukushima Prefecture, Japan after the Fukushima fallout

Levels of radiocesium (134Cs + 137Cs) contamination in lake water, bottom sediment, plankton, and fish were investigated in three geographically separated lakes in Fukushima Prefecture (Lake Hayama, Lake Akimoto, and Lake Tagokura) between June 2012 and November 2013. Levels of contamination differed among the three lakes, with the highest levels of each measured component in Lake Hayama, followed by Lake Akimoto, and the least contamination in Lake Tagokura. Among the lakes, the magnitude of contamination decreased with distance from the Fukushima Dai-ichi Nuclear Power Plant. Mean radiocesium concentrations were higher in piscivorous fish than in other fish, possibly reflecting differences in trophic level. The radiocesium concentrations in some fish species decreased significantly by 33–65 % during the period between 2012 and 2013. Radiocesium concentrations of the lake water, bottom sediment, plankton, and fish were significantly correlated with surface soil radiocesium content near lake sites.

The change in fractions of organic substances in water in the intermediate oxidation process

This article presents the results of a study on the changes in the content of both biodegradable and non-biodegradable fractions of dissolved total organic carbon. The studies were conducted on a technical scale in surface and mixed water (underground water after aeration mixed with surface water after micro sieve) purification plants, and the oxidation process was performed with ozone and a mixture of chlorine and chlorine dioxide, respectively. The study demonstrated a significant increase in the biodegradability of organic substances in the oxidation process regardless of the type of oxidant used. Ozone turned out to be the most effective oxidant in eliminating and transforming organic substances, compared with chlorine and chlorine dioxide. In the case of the utilization of a mixture of chlorine and chlorine dioxide, a greater reactivity of chlorine dioxide with organic matter, especially refractive substances, was determined. In both water treatment plants, the transformation of high molecular weight organic substances to smaller ones dominated over the mineralization of total organic carbon. The type and size of the transformation of organic matter depended mainly on the type of oxidant utilized, and not on the level of water contamination.

The influence of chlorinated aromatics’ structure on their adsorption characteristics on activated carbon to tackle chemical spills in drinking water source

This study focused on evaluating the efficiency of powdered activated carbon (PAC) adsorption process and tackling chlorobenzenes and chlorophenols spill in drinking water source. The adsorption kinetics and PAC's capacities for five chlorobenzenes and three chlorophenols at drinking water contamination levels were studied in order to determine the influence of different functional groups on the adsorption behavior. The results showed that PAC adsorption could be used as an effective emergency drinking water treatment process to remove these com- pounds. The adsorption kinetics took 30 min to achieve nearly equilibrium and could be described by both pseudo first-order and pseudo second-order models. A mathematic relationship was developed between the pseudo first-order adsorption rate constant, k1, and the solutes' properties including lgKow, polarizability and molecular weight. The Freundlich isotherm equation could well describe the adsorption equilibrium behaviors of chlorinated aromatics with r 2 from 0.920 to 0.999. The H-bond donor/acceptor group, hydrophobicity, solubility and molecular volume were identified as important solute properties that affect the PAC adsorption capacity. These results could assist water professionals in removing chlorinated aromatics during emergency drinking water treatment.

Pseudo-likelihood Estimation of Multivariate Normal Parameters in the Presence of Left-Censored Data

Environmental data often include left-censored values reported to be less than some limit of detection (LOD). While simple imputation of a specific value such as LOD/2 is common, maximum likelihood methods accounting for censoring provide alternate ways of analyzing such data. Concentration levels of contaminants in water, for example, are typically modeled with normal or lognormal distributions. Corresponding maximum likelihood estimates (MLEs) of means and variances in univariate analyses can be obtained from standard software packages; however, multivariate analyses may be more appropriate when multiple measurements come from the same entity. For example, measures of several dissolved trace metals may be derived from freshwater stream samples. In less-polluted areas, one or more of these measures fall below the LOD. An index of overall contamination may be formed as a linear function of these measures. The desire to estimate this index led to the need to estimate the parameters in the presence of nondetects, which led to our proposed method. We propose a pseudo-likelihood method utilizing pairs of variables that provides MLEs of mean and unstructured covariance parameters corresponding to a multivariate normal or lognormal distribution in the presence of left-censored data. In conducting hypothesis tests and estimating functions of MLEs with standard errors, we apply this method to trace metal concentration data collected from freshwater streams across Virginia.

Laser-induced breakdown spectroscopy application in environmental monitoring of water quality: a review.

Water quality monitoring is a critical part of environmental management and protection, and to be able to qualitatively and quantitatively determine contamination and impurity levels in water is especially important. Compared to the currently available water quality monitoring methods and techniques, laser-induced breakdown spectroscopy (LIBS) has several advantages, including no need for sample pre-preparation, fast and easy operation, and chemical free during the process. Therefore, it is of great importance to understand the fundamentals of aqueous LIBS analysis and effectively apply this technique to environmental monitoring. This article reviews the research conducted on LIBS analysis for liquid samples, and the article content includes LIBS theory, history and applications, quantitative analysis of metallic species in liquids, LIBS signal enhancement methods and data processing, characteristics of plasma generated by laser in water, and the factors affecting accuracy of analysis results. Although there have been many research works focusing on aqueous LIBS analysis, detection limit and stability of this technique still need to be improved to satisfy the requirements of environmental monitoring standard. In addition, determination of nonmetallic species in liquid by LIBS is equally important and needs immediate attention from the community. This comprehensive review will assist the readers to better understand the aqueous LIBS technique and help to identify current research needs for environmental monitoring of water quality.

Specificity of coliphages in evaluating marker efficacy: A new insight for water quality indicators

Conventional procedures for qualitative assessment of coliphage are time consuming multiple step approach for achieving results. A modified and rapid technique has been introduced for determination of coliphage contamination among potable water sources during water borne outbreaks. During December 2013, 40 water samples from different potable water sources, were received for water quality analyses, from a jaundice affected Municipality of West Bengal, India. Altogether, 30% water samples were contaminated with coliform (1–20cfu/ml) and 5% with E. coli (2–5cfu/ml). Among post-outbreak samples, preponderance of coliform has decreased (1–4cfu/ml) with total absence of E. coli. While standard technique has detected 55% outbreak samples with coliphage contamination, modified technique revealed that 80%, double than that of bacteriological identification rate, were contaminated with coliphages (4–20pfu/10ml). However, post-outbreak samples were detected with 1–5pfu/10ml coliphages among 20% samples. Coliphage detection rate through modified technique was nearly double (50%) than that of standard technique (27.5%). In few samples (with coliform load of 10–100cfu/ml), while modified technique could detect coliphages among six samples (10–20pfu/10ml), standard protocol failed to detect coliphage in any of them. An easy, rapid and accurate modified technique has thereby been implemented for coliphage assessment from water samples. Coliform free water does not always signify pathogen free potable water and it is demonstrated that coliphage is a more reliable ‘biomarker’ to ascertain contamination level in potable water.

English

This study investigated the composition and structure of the parasitic communities in Oreochromis niloticus with respect to levels of water quality in three different ecosystems. A total of 366 O. niloticus were examined from three water courses: CLAR ponds, (unpolluted), Abbassa privet ponds (slightly polluted) and Manzalla ponds (polluted). Trematodes, monogeneans, cestodes and acanthocephalans were found in all the sample sites. Trematodes dominate the parasite population. Clinostomum tilapiae, Euclinostomum heterostomum, Diplostomum spathaceum, Posthodiplostomum minimum, Mesostephanus appendiculatus, Haplorchoides cahirinus, Cichlidogyrus aegypticus, Acanthosentis tilapiae and larval stages of Polyonchobothrium clariass were found in all the sampled sites, but the distribution of these parasitic species varied between the three ponds. Meanwhile, P. clarias, E. heterostomum; and A. tilapiae were completely absent in the severely polluted site. The observed composition and structural changes among the sites were studied; the variability of the calculated infection indices (prevalence, mean abundance and mean intensity); and the degree of interactivity among parasites, as well as parameters of species richness and diversity suggest that the structure of parasite communities are affected by the water contamination levels. &nbsp; Key word: Oreochromis niloticus, Polyonchobothrium clarias, Euclinostomum heterostomum, Acanthosentis tilapiae, multistressor environments.

Use of Personal Glucose Meters for the Detection of E. Coli in Water

Contamination of potable water with pathogenic bacteria such as Escherichia coli (E.coli) is a major concern in the developing countries. Often water is consumed without any prior treatment leading to several water borne ailments such as diarrhea. According to United States Environmental Protection Agency (USEPA), the total concentration of E.coli in potable water should be restricted to 0 Colony Forming Units (CFU) per 100 ml of water for potable water and 126 CFU/100ml for recreational water. The conventional methods of pathogen detection generally involve transporting the contaminated water samples to centralized laboratories where detection and quantification techniques are based on instant culturing of bacteria, enzymatic reactions, and molecular (immunological or genetic) methods of detection. These processes often take 24 – 48 hours to produce results and are often expensive due to the additional requirements of resources and qualified personnel. Such a system for water monitoring is not suitable for low-resource settings. Rapid, easy to use and inexpensive detection systems need to be developed in order to empower individual households to regularly monitor their bacteriological water quality.One of the best examples of such rapid and simple detection systems is the Personal Glucose meter (PGM), which is used by patients with diabetes to regularly monitor their blood glucose levels. This system is based on an electrochemical reaction where in the glucose present in the sample is made to react with an enzyme electrode containing glucose oxidase and the resulting change in the current is measured, which in turn can be correlated to the concentration of the glucose. We have developed a simple method for the detection of E.coli and total coliform using PGMs by monitoring the consumption of glucose as a carbon source by E.coli during their growth cycle. Contaminated water samples with bacterial concentrations in the range of 2-2x108 CFU/mL were supplied with glucose solutions with known concentrations and Lauryl Tryptose (LT) broth as the growth medium in order to induce the consumption of glucose by E.coli. The drop in glucose concentrations in these samples was measured every hour with a PGM. It was observed that samples with very high concentrations of E.coli (2x106 - 2x108 CFU/mL) showed a drop in the glucose concentrations within an hour and samples with extremely low E.coli concentrations (2 CFU/mL) showed a drop in glucose concentrations within a maximum of 8 hours. This method can provide qualitative as well as quantitative results to determine the level of contamination in potable water. The time required to produce results with this method is much lower than the conventional colony counting method and the cost involved is quite less compared to the equipment required for ELISA plate readers. The current PGMs available in the market are portable and can produce reliable quantitative results. These systems are quite robust, simple and can be used by any untrained person. PGMs have also been recently integrated with smart phones thereby resulting in a further increase in their base of users. The E.coli detection kit presented here is simple, easy to use, reliable, cost effective and does not involve any toxic reagents or end products. This method doesn’t warrant any special training and can be used by any unskilled person on site at the source of water.

Water used to moisten vegetables is a source of Escherichia coli and protozoan parasite contamination at markets in Hanoi, Vietnam

The study was done to assess the level of fecal (Escherichia coli) and protozoan parasite (Cryptosporidium spp. and Giardia spp.) contamination in water used by traders to moisten vegetables at markets in Hanoi, Vietnam. A total of 200 splashing water samples from markets located within eight districts were analyzed for E. coli and Cryptosporidium spp. and Giardia spp. (oo)cysts. Giardia cysts were found in 17 splashing water samples and Cryptosporidium oocysts in nine samples, with median values of 20 cysts ml(-1) and 10 oocysts ml(-1), respectively. E. coli was found with a median concentration of 636 cfu ml(-1) and its occurrence was negatively correlated with the numbers of protozoan parasites. The splashing water was kept in buckets that were rarely cleaned and often used for handwashing. The finding of these pathogens in splashing water is likely to represent real food safety hazards.