Water Contamination Levels Research Articles

FentonSims®: A novel interactive simulation tool for computational kinetics of microcontaminant removal by the solar photo-Fenton process

This work presents, for the first time, a simulation app for the mechanistic understanding of the solar photo-Fenton process applied to the removal of microcontaminants contained in wastewater treatment plant secondary effluents. FentonSims® incorporates three mechanistic kinetic models previously developed for the process at acidic and neutral pH with different iron chelators (nitrilotriacetic acid and ethylenediamine-N,N’-disuccinic acid). The end-user can simulate the operation of perfect mixing raceway pond reactors in batch and continuous mode as a function of environmental (UVA radiation and water liquid temperature) and operating conditions (hydraulic residence time, liquid depth and reagent concentrations). Furthermore, this tool allows the assessment of different levels of water contamination, and estimations for reagent conversion, microcontaminant removal yield and water treatment capacity are shown in the graphical user interface. Simulations are conducted in an intuitive and easy-to-use app, so no programming skills are required, and all data are saved, allowing the user to analyse a wide range of operating scenarios. Therefore, FentonSims® is a valuable didactic tool for graduate students and water treatment professionals interested in the applicability of the solar photo-Fenton process and its phenomenological understanding.

Ag2O-adorned ZnO nanostructures: cooperative and sustainable nanomaterial system for effective reduction and mineralization of hazardous water pollutants

Organic water pollutants like nitroaromatics and synthetic dyes are causing serious threats to water. Ever-growing urban and industrial activities along with population explosion are rapidly contributing severe level of water contamination. Semiconducting nanomaterial-based photocatalysis has been proven to be an effective process for degradation of organic water pollutants. In the current study, visible light active Ag2O-adorned ZnO nanostructures were fabricated by a simple two-step hydrothermal method and the prepared nanostructures were utilized for the photocatalytic mineralization of rhodamine B (RhB) dye with visible light radiation. The catalytic potential of as-synthesized nanostructures was also investigated for the reduction of nitroaromatics (4-NP and 4-NA) and RhB dye in the presence of NaBH4. The Ag2O-adorned ZnO nanostructures prepared with 5% of silver nitrate denoted as ZnO/Ag2O (5%) demonstrated stupendous photomineralization activity against RhB dye as almost 100% degradation of RhB dye was achieved within 100min of reaction time at pH = 6. The kinetic study revealed that the degradation reaction followed the pseudo-first-order kinetics and the kinetic rate constant (k) of photodecolorization reaction for optimal catalyst was calculated to be 61.4 × 10-3min-1. The nanostructures revealed excellent recyclability and photostability as 95% activity of the catalyst was preserved even after the fifth cyclic run. The catalytic reduction of the 4-NP, 4-NA, and RhB dye was completed in 21, 12, and 40min, respectively, in the presence of ZnO/Ag2O (5%) and NaBH4 solution. The kinetic rate constant values for the reduction reactions were determined to be 229.6 × 10-3, 454.2 × 10-3, and 105.5 × 10-3min-1 for 4-NP, 4-NA, and RhB dye, respectively. Thus, the obtained results suggest that the components of the prepared nanosystem help in mutually strengthening the catalytic and photocatalytic abilities of each other, indicating the development of a cooperative and sustainable nanomaterial system in the current study.

Sweet Fuel: A Political and Environmental History of Brazilian Ethanol

Sweet Fuel: A Political and Environmental History of Brazilian Ethanol

An assessment of the underground water collected from Ogbete Area Enugu State, Nigeria

Water contamination has become a global challenge which must be tackled. This study examined the contamination level of water in four locations at Ogbete area Enugu state. Carters street had the highest pH of 5.23 which is below the WHO standards limits for drinking water. The conductivities ranged from the highest conductivity 1445 µs/cm, which is below the WHO limits (8-10,000 µs/cm), TDS (1000 mg/l., TSS (WHO (500 mg/l). For alkalinity, the four locations were all below the (150 mg/l) standard set by World Health Organisation. Results showed that most of the physicochemical, biological and heavy metals parameters considered in this study were significantly above the permissible or allowed by WHO. It is therefore recommended that the water should be treated before use.

A systematic and comparative study of Water Quality Index (WQI) for groundwater quality analysis and assessment.

Water is essential for human survival. Its quality must be maintained to prevent any potential health problems. Pollution and contamination are likely causes of the water quality decline. This may occur if the world's rapidly expanding population and industrial facilities fail to clean their effluent correctly. The Water Quality Index, often known as the WQI, is the indicator most frequently used to characterize surface water quality. This study emphasizes several WQI models that could be of use to us in determining the level of water quality available in the various areas. We have tried to cover multiple essential procedures and their corresponding mathematical counterparts. In this article, we also examine the applications of index models in different types of water bodies, such as lakes, rivers, surface water, and groundwater. The level of contamination in water due to pollution directly affects the overall quality of water. A pollution index is a valuable tool for measuring the level of pollution. Concerning this, we have discussed two approaches, namely, the Overall Index of Pollution and Nemerrow's Pollution Index, which demonstrate the most effective technique to evaluate the water standard. Examining the similarities and differences between these approaches may offer researchers a suitable starting point to delve further into assessing water quality.

Comparative Assessment of Seasonal Variations in the Quality of Surface Water and Its Associated Health Hazards in Gold Mining Areas of Osun State, South-West Nigeria

Industrial and urban development are contributing to an increase in global environmental degradation. Therefore, the release of heavy metals from mining-related operations into surface water is harmful to human health. But as anthropogenic influences on the environment grow, surface water characteristics are also alter, impacting aquatic creatures. In order to analyze the acceptability of the surface water in the gold mining area for drinking and irrigation uses, different quality water assessment methodologies were incorporated in this research. In light of this, the purpose of the current study is to comprehend how the hydrogeochemistry and appropriateness of surface water for drinking and irrigation vary every month. The study employed standardized analytical techniques. According to APHA recommendations, all sampling, conservation, transportation, and analysis were completed (2012). All collected samples were transported to the study lab while being kept in an icebox to prevent the degradation of the organic components. As a result, the study is focused on the contamination level in the surface water for a year. Overall, the study highlights important pollutants impacting surface water quality as it passes through Osun State's gold mining regions. Finally, it has been determined that the following criteria are crucial for the stretch of this research season: DO, Hardness, Turbidity, Chloride, Potassium, Nitrate, Lead, TSS, Cadmium, Chromium, Sulphate, Manganese, Mercury, and Arsenic. Most of the physicochemical variables examined in this study fell within their corresponding standard limits. Based on the results of this study, the appropriate constituted authority is encouraged to continuously monitor and assess surface water quality suitability for drinking, domestic, and irrigation purposes by keeping track of the effects of water contaminants and detecting any changes in the water quality. To safeguard and maintain groundwater quality and public health, it is advised that appropriate regulatory policies and water treatment procedures be employed in the area. Additionally, it is proposed that when enhancing water quality and investigating the sustainable use of water resources, surface water pollution should be taken into consideration.

Bacterial Contamination and Antimicrobial Resistance in Drinking Water From Food and Drinking Establishments in Shashemane Town, Ethiopia

We investigated the bacteriological quality of drinking water and antimicrobial resistance of bacterial isolates in food and drinking establishments in Shashemane town, Ethiopia. A cross-sectional study was conducted from July to August 2022. One hundred water samples were collected from the tap water and storage containers of 50 selected establishments. All the collected samples were analyzed for bacteriological and antimicrobial susceptibility tests using standard procedures. The study found approximately 80% of water samples from the tap and all water samples (100%) from storage containers were contaminated with total coliforms. E. coli was detected in 20% and 26% of water samples from the tap and storage containers, respectively. A total of 68 bacterial isolates were identified, including E. coli (33.8%), Staphylococcus (25%), Salmonella (17.64%), Klebsiella (11.76%), Shigella (10.29%), and Pseudomonas (1.4%). The highest resistance by the isolates was observed against ampicillin (96%), followed by amoxicillin (94%), cotrimoxazole (76.8%), chloramphenicol (36%), gentamycin (23%), ciprofloxacin (23%), and ceftriaxone (12%). The study concluded that drinking water in food and drinking establishments was found vulnerable to microbiological contamination and it is a health risk to consumers. The level of contamination in stored water was found higher than tap water. In addition, antimicrobial-resistant bacteria such as E. coli, Salmonella, Shigella, Klebsiella, and Staphylococcus aureus were detected in both tap water and stored water. Therefore, awareness should be given to food handlers and owners of the establishments on hygienic water handling practices by the regulatory bodies of Shashemane town and stakeholders.

Using Zirconium MOF Packed Microfluidic Electrochemical Cell As PFOA Screening Sensor in Water Source

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are human-made chemicals with high chemical resistance and thermal stability. The extremely stable fluoro-carbon (F-C) skeletons enable PFAS molecules can exist stably in nature especially in the water sources for a long time concerning thermal, chemical, and biodegradation. Perfluorooctanoic acid (PFOA) is one of the most dominant environmental contributors, and its half-life in water has been estimated to be longer than 92 years. Therefore, the monitoring of PFOA level in the water source is needed. It is reported that Zirconium (Zr) based metal-organic frameworks (MOFs) have shown considerable affinity to PFOA molecules. In addition, electrochemical impedance spectroscopy (EIS) as a rapid and sensitive detection method (based on measuring the impedance changes at the electrode/solution interface) is perhaps the most frequently used technique in the investigation of affinity-based transducers.In the pursuit of building a highly efficient screening sensor to PFOA molecules. In this work, the application of Zr based MOF in NP-μFEC as a combined sensing platform to PFOA molecules is conducted. Here, the NP-μFEC is our group proposed new impedance sensing platform with enhanced, three-dimensional distributed electric field. To validate the feasibility of Zr based MOF packed NP-μFEC’s sensing performance. The work is conducted with a ranging concentration of PFOA (in 0.1X PBS) from 150 to 10 ng/L. We finally find that the proposed combination of Zr based MOF and NP-μFEC can show an excellent response to the PFOA molecules, which offers a detection limit lower than the established US Environmental Protection Agency (EPA)'s water contamination level (70 ng/L).

Factors associated with bacterial contamination of shallow well water sources. Case Study of Juja hostels Kiambu County

The use of water from polluted water sources poses numerous public health challenges in developing countries. The ultimate purpose of any solid and liquid waste management plan is to mitigate environmental pollution; these goals become unachievable in the absence of a participatory approach to integrated waste management. This study sought to determine the extent of underground pollution of groundwater sources in Juja Town. Sanitary inspection and water quality analysis are complementary and valuable tools for characterizing and protecting water safety. The quality of the shallow wells is of great importance because it is used for consumption in Juja hostels. A two-stage cluster sampling strategy was adopted to obtain a representative sample size. Data collection involved the administration of questionnaires and field observation checklists, and E. coli levels present in the water were determined by the number of positive tubes in the table of computation of most probable number (MPN). Results showed that the predominant types of waste disposal practices observed in Juja were septic tank systems (77%) for liquid waste and private collection (87.3%) for solid waste methods. Sixty-eight per cent of the water samples were found to be positive (they exceeded the WHO (2004) maximum permissible load of 0.01/100 ml for drinking water. Three sanitary risk factors had a statistically significant effect on the dependent variable: the distance of the septic tank from the well on the level of water contamination (0.016), the liquid waste management plan (0.039), and the fitness of the water well cover on the level of water contamination (0.024). Shallow well water sources are unsuitable for use in food processing and drinking due to the presence of E. coli bacteria. The consequences of consuming contaminated water can be expensive to treat. Water from wells in Juja is contaminated with E. coli levels ranging from <3 - >1000 MPN/g, indicating fecal contamination in the area's underground water sources.

A highly sensitive, easy-and-rapidly-fabricable microfluidic electrochemical cell with an enhanced three-dimensional electric field

An NP-μFEC is a reusable, novel microfluidic electrochemical cell with multiple non-planar interdigitated microelectrode arrays, minimal sample volume, and enhanced electric field penetration for highly sensitive electrochemical analysis. (i) The NP-μFEC features spatial 3-electrode architecture, and a small sample volume (∼4 μL). (ii) Here, [Fe(CN)6]3-/4- redox couple are used as an electrochemical reporter. The effects on the electrochemical properties of NP-μFEC due to the change in the reference electrode (RE) and counter electrode (CE)'s position with respect to the working electrode (WE) position are analyzed. For NP-μFEC, the position of the RE with respect to the WE does not affect the CV, DPV electrochemical profiles. However, the spacing between the CE and WE plays a significant role. (iii) The enhanced three-dimensional electric field penetration in NP-μFEC is validated by finite element analysis simulation using COMSOL Multiphysics. (iv) Without electrode surface modifications, NP-μFEC shows a detection limit (DL) of ∼2.54 × 10−6 M for aqueous [Fe(CN)6]3-/4- probe. (v) The DL for Cu2+, Fe3+, and Hg2+ are 30.5±9.5 μg L−1, 181±58.5 μg L−1, and 12.4±1.95 μg L−1, respectively, which meets the US Environmental Protection Agency (EPA)'s water contamination level for Cu, Fe, and is close to that for Hg (EPA limits are 1300 μg L−1, 300 μg L−1, and 2 μg L−1, respectively). (vi) Further, using a pressure-sensitive adhesive layer to form the channel and create the NP-μFEC configuration simplifies the manufacturing process, making it cost-effective and allowing for rapid adoption in any research lab. NP-μFEC is used to detect heavy metal ions in water. This demonstrates that cost-effective, easy-to-fabricate NP-μFEC can be a new sensitive electrochemical platform.

Development and Validation of an ICP-MS Method for the Detection of Platinum in the Lebanese Aquatic Environment

Lebanon is a Middle Eastern country located on the eastern Mediterranean coast. Compared to other countries in the MENA (Middle East North Africa) region, Lebanon is considered the richest in water resources. However, due to inadequate water management, Lebanese water resources are under stress. Water pollution is one of the main problems causing major concerns. The contamination of Lebanese surface water originates predominantly from the discharge of untreated municipal and industrial wastewater. With only a few studies investigating the level of water contamination in Lebanon, this research is the first to report the level of platinum in numerous rivers, three wastewater treatment plants, and two untreated sewage outfalls in coastal areas across Lebanon. To determine the platinum levels, an Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) method was developed and validated in compliance with the ICH guidelines. The method demonstrated acceptable sensitivity with LOQ and LOD equal to 2.35 and 0.56 ng L−1, respectively. The level of total platinum in the Lebanese water samples ranged between 22.44–53.32 ng L−1. These concentrations were all above the baseline concentration of platinum in tap water indicated by WHO and aligned with previous studies in other countries. Although the baseline concentration of platinum in Lebanese water resources is unknown and the source of the total platinum detected in this study could not be identified, these preliminary findings could serve as a foundation for future research.

Genotoxic and histopathological effects of the Ili River (Kazakhstan) water pollution on the grass carp Ctenopharyngodon idella

ABSTRACT In the present study, genotoxic, histological and hematological effects of water pollution were evaluated in Ctenopharyngodon idella from the Ili river. Water and fish were sampled at three sites. The concentrations of the following heavy metals were measured in the water: Pb, Co, Mg, Cd, Cu, Zn, Fe. Water pollution with metals gradually increased from P1 to P3: in P1, Cu and Fe levels exceeded the maximum permissible concentrations for fish culture, in P2 – Pb, Cu, Zn, Fe, and in P3 – Pb, Cd, Cu, Zn, Fe. In fish from the Ili river, the highest frequency and severity of DNA damage and liver damage were noted in P3, the lowest in P1. Gill lesions were more pronounced and frequent in fish from P3 compared to grass carp from P2 and P1. Fish from P1 showed a higher frequency of neutrophils and a lower percentage of lymphocytes compared to the control. The results also revealed: genotoxicity measured by comet analysis and liver histology were the most sensitive and showed the magnitude of lesions directly related to the level of water contamination. Gill histology also clearly showed pathological changes caused by pollution, while differential leukocyte count was the least useful indicator, as it showed only minor differences between fish from unpolluted and polluted water.

Assessment of pollution indices and human health risk related to 13 heavy metal contents in surface water of Sihke Pond (Van), Turkey

Heavy metals may cause serious problems for human health in contaminated water resources. Therefore, this study aimed to evaluate the metal contamination levels in Sihke Pond surface water and assess the possible human health risk for children and adults through ingestion of the surface water. The concentrations of thirteen heavy metals (aluminum, arsenic, cadmium, cobalt, chromium, copper, iron, manganese, molybdenum, nickel, lead, selenium, and zinc) were determined monthly using the inductively coupled plasma-mass spectrometer between September 2019 and August 2020. Heavy metal pollution index and metal index were used to determine the metal pollution level. Non-carcinogenic risks including hazard quotient and hazard index were calculated and the carcinogenic risk values were estimated for both age groups. The mean value of heavy metals was decreased in the order of manganese > molybdenum > iron > chromium > zinc > arsenic > cobalt > copper > nickel > lead > aluminum > cadmium > selenium. The mean heavy metal pollution index value was determined as 110.8 and classified as totally not suitable. The mean metal index value was also included in the slightly affected class. The hazard quotient for arsenic, cobalt, and molybdenum, and hazard index values had values >1 for both groups. The carcinogenic risk caused by arsenic, chromium, and lead were all above the tolerable limit of 1.0 × 10−4. Thus, the non-carcinogenic risk and carcinogenic risk results for children and adults exceed the threshold values. Consequently, the Sihke Pond surface water is contaminated with heavy metals and is not suitable for direct consumption.

Environmental recovery from 137Cs contamination in Japanese coastal waters shown by comparison of temporal distributions with European seas

We compared the spatiotemporal distributions of 137Cs in the European Baltic Sea (semi-enclosed) and the North and Norwegian Seas (open to the ocean) after the Chernobyl Nuclear Power Plant (CHNPP) accident, with those in Japanese coastal regions, including the waters off Miyagi, Fukushima, and Ibaraki prefectures, open to the western North Pacific, after the Fukushima Nuclear Power Plant accident. The effective half-lives 1–9 years after each accident were shortest (1.6–4.7 y) in Japanese coastal waters, 4.9 y in the North Sea, and 14.4 y in the Baltic Sea, suggesting that decreases in 137Cs concentrations are largely dependent on the local geography, and that the dilution–diffusion effect of seawater was greater in the Japanese coastal waters. The effective half-lives of 137Cs in the surface waters of European seas, based on 30 years of data after the CNPP accident, became longer, ranging from 8.4 to 11.9 y. This may be due to the influence of rivers, and a delay in the decrease in 137Cs levels caused by the small difference in radioactivity concentrations between the seas and diluting waters. These results could contribute to the prediction of contamination levels in Japanese coastal waters in the future.

Evaluation of Drinking Water Quality and Bacterial Antibiotic Sensitivity in Wells and Standpipes at Household Water Points in Freetown, Sierra Leone.

Water quality surveillance can help to reduce waterborne diseases. Despite better access to safe drinking water in Sierra Leone, about a third of the population (3 million people) drink water from unimproved sources. In this cross-sectional study, we collected water samples from 15 standpipes and 5 wells and measured the physicochemical and bacteriological water quality, and the antimicrobial sensitivity of Escherichia coli (E. coli) in two communities in Freetown, Sierra Leone in the dry and wet seasons in 2021. All water sources were contaminated with E. coli, and all five wells and 25% of standpipes had at least an intermediate risk level of E. coli. There was no antimicrobial resistance detected in the E. coli tested. The nitrate level exceeded the WHO’s recommended standard (>10 parts per million) in 60% of the wells and in less than 20% of the standpipes. The proportion of samples from standpipes with high levels of total dissolved solids (>10 Nephelometric Turbidity Units) was much higher in the rainy season (73% vs. 7%). The level of water contamination is concerning. We suggest options to reduce E. coli contamination. Further research is required to identify where contamination of the water in standpipes is occurring.

Assessment of heavy metal contamination levels and health risks in environmental media in the northeast region

• Analyze heavy metal contamination levels in soil, water, and air. • Heavy metals from media are hazardous to human health in many ways. • Major pollution is affected by industry and agriculture. • Characterization of human contamination by heavy metals in human hair. • Environment causes health hazards to humans and makes sustainability suggestions. Rapid development in Northeast China has brought serious heavy metal pollution to the environmental media (soil, surface water and air). This paper presents a study on the spatial and temporal distribution, source analysis, potential ecological risk and human health risk assessment of heavy metals in environmental media in Northeast China, aiming to provide a theoretical foundation for controlling and reducing heavy metal pollution. The study shows the following results:1. Developed cities in Jilin Province (Changchun and Jilin) have the most serious heavy metal pollution. 2. The main sources of heavy metals in soil are metallurgical production and agricultural production. The main sources of heavy metals in surface water are industrial production, domestic waste, and sewage. The main sources of heavy metals in the air are vehicle emissions, biomass combustion and coal burning for winter heating. The sources of heavy metals are listed in order of decreasing significance in all three cases above. 3. Soil, surface water and air heavy metal concentrations all have a significant impact on human health. 4. Heavy metals in soil, surface water and air are an ecological risk and already pose a carcinogenic risk to humans.

Ecosystem based approach to delineate coastal degradation of Hawks bay, Karachi, Pakistan

Hawks Bay (HB) a renowned recreational beach, an important small scale fishery and nesting ground of an endangered turtle species encountering massive environmental degradation. Its eastern bay cover scattered mangrove patches and the western bay embraces sandy and rocky beach that terminus the area into great ecological and economic concerns. Here, we have figured out tendency of contamination entering in the ecosystem and elaborate food ∼ web dynamics around HB. An integrated approach was applied to evaluate level of contamination in water, sediments, planktons, seaweeds, mangrove leaves, crabs and fishes. In the sampled population phytoplankton were comprises of (39 Taxa), zooplankton (21), crab (1) and fishes (9) from pelagic demersal domains. The concentration of copper (Cu), iron (Fe), zinc (Zn), lead (Pb) and chromium (Cr) were detected using double-beam Atomic Absorption Spectrophotometer (AAS). The trophic transfer (TTF), contamination factor (CF), pollution load index (PLI), bioaccumulation factor (BAF) and accumulation factor (AF) were calculated round the year. The CF reveals that the area is moderately contaminated whereas PLI (>1) indicate that area is massively polluted by the industrial wastes. Multivariate approach of Principle Component Analysis was applied using pooled data of TTF that defines PC-I (41.56%) and PC- II (31.44%) variability among axes. Evaluation of metal contamination from micro to macro and from surface to bottom exhibits considerable load being received by HB ecosystem echoes stringent actions to curb further degradation of an important area.

TRACE METAL CONTAMINATION AND ITS INDEXING APPROACH FOR SHIVNATH RIVER WATER, C.G., INDIA

The present work is aimed at assessing the trace metal contamination and its indexing approach for Shivnath River, one of the major tributaries of Mahanadi River of Durg, Chhattisgarh with respect to some trace metals like Al, Fe, Mn, Cu and Cr. This enables us to assess whether the quality of water is fit for drinking, irrigation and industrial use or not. For this study samples were collected for 2017 and 2018 in all three seasons and subjecting the samples to a comprehensive selected metal analysis. For the assessment of contamination level in water of the study area the data obtained were statistically analyzed first and then calculated for pollution index (PI), Contamination Index (CI), Heavy Metal Pollution Index (HPI). The mean of HPI values found were 67.22 and 75.12 in summer season of 2017 and 2018 respectively. The CI and PI values were less than 1.0 which indicates the water is not critically polluted with respect to heavy metals. It is due to presence of enough flow rate of River water, the metal concentration from domestic and urban runoff has been diluted rapidly with respect to a very small distance.

Analisis Kandungan Cemaran Bakteri Coliform Pada Air Rendaman Tahu di Pabrik Tahu Wilayah Kalideres Jakarta Barat

Tofu is a food source containing high vegetable protein. Tofu is in great demand by most of the Indonesian people because it contains high nutrition and the price is relatively cheap and affordable. To produce tofu requires good hygiene and sanitation, such as providing clean raw materials and water sources that are free from contamination. To determine whether the water source has been contaminated with microbes or not, the Coliform bacteria indicator in the water sample is used. In testing Coliform bacterial contamination in water or raw materials, the Most Probable Number (MPN) method is used to calculate the amount or level of microbial contamination in determining the quality or quality of water and raw materials by referring to the MPN table. This study aims to determine the level of Coliform bacteria contamination in tofu soaking water in a tofu factory in the Kalideres area of ??West Jakarta. The design of this research is a descriptive laboratory type which was carried out in March-June 2020 at the Indonesian Social Solidarity STIKes Laboratory. Based on the results of the research on the presumptive test, it was found that 1 positive tube was contaminated with Coliform in the KR tofu factory and 3 positive tubes at the DN factory. The presumptive test was continued to confirmatory test and found 5 positive tubes polluted at the DD factory, 2 positive tubes at the KR factory and 3 positive tubes at the DN factory. The positive tube from the confirmation test was calculated for the contamination index value (MPN) and obtained 21000 mpn/ml for the DD factory, 4000 mpn/ml for the KR factory and 9000 mpn/ml for the DN factory. It can be concluded that there is Coliform bacterial contamination in all tofu soaking water samples in 3 tofu factories with the MPN index value having passed the contamination threshold.

Effects of abandoned coal mine on the water quality

ABSTRACT Improving effective strategies to control acid mine drainage (AMD) in abandoned mine areas is a significant challenge because of water quality issues. AMD is a serious water pollution problem. The water in the area where the mine is located acquires an acidic character, the pH level of the environment decreases, the concentration of heavy metals increases with their dissolution in the acidic environment, and can cause serious environmental pollution by creating a toxic effect for all living things. However, acidic characteristics are not observed in the waters at high pH levels; a basic environment is formed; the heavy metal dissolution slows down; and the precipitation of minerals begins. In such an environment, it is not possible to observe AMD formation and heavy metal pollution. If AMD source is characterized, the most effective strategies can be developed to control the acidic effluents. The main aim of this work was to investigate the potential impact of Ovacik abandoned, coal mine (Cankiri, Turkey) on the water quality in the areas around the mine. Water samples were collected along the open pit area (abandoned), dump sites and coal storage area. Effluent characterizations were investigated for the better evaluation of the water contamination level to develop the successful treatment strategies. In the studies conducted in the same field in 2010–2011, it was determined that the water pH changes between 6.64 and 8.13. Similarly, in this study, the results showed that the pH values of water streams in the abandoned mine were measured between 7.28 and 8.94 with no heavy metal contamination. Although the coal deposit exhibits AMD source minerals, the rock formations which have alkaline content prevented AMD in the considered site.