EPA Standards Research Articles

Assessing Physico-Chemical Parameters of Potable Water in Dhankuta Municipality of Nepal

This paper intends to describe the physico-chemical parameters and bacteriological analysis of potable water used for drinking and domestic purposes in Dhankuta municipality of Nepal. The results obtained were compared with WHO and EPA standards for drinking and recreational water. The physico-chemical parameters used to quantify the quality of drinking water were pH, alkalinity, TDS, DO, BOD, salinity, turbidity, heavy metals and anion measurements. The results of such analysis have been explained in discussion chapter of this paper and revealed tolerable to higher values as recommended by WHO standards. Total coliform and fecal coliform counts analyzed in the water samples were concluded the fecal and organic contaminations in the drinking water resources.

Evaluation of polycaprolactone as a new sorbent coating for determination of polar organic compounds in water samples using membrane-SPME.

Commercially available solid-phase microextraction fibers used for isolation of polar analytes are based on the adsorption phenomenon. In consequence, typical limitations bonded with analytes displacement and matrix effects are very frequent. In the present study, alternative solution is described. Polycaprolactone (PCL) was used for the first time as sorbent to isolate polar organic compounds from water samples using the membrane–solid-phase microextraction (M-SPME) technique. In this technique, due to protective role of the mechanically and thermally stable polydimethylsiloxane (PDMS) membrane, internal polar coating might be melted during extraction and desorption of analytes. In consequence sorbents with low melting points like a PCL might be utilized. Based on chromatographic retention data, triazines were selected as a model compounds for evaluation of the sorptive properties of the polycaprolactone. Applying the screening plan and central composite design, statistically significant parameters influencing extraction efficiency were determined and optimized. The analysis of variance confirmed the significant influence of temperature, salt content, and pH of samples on the extraction efficiency. Besides the new PCL/PDMS fiber, a commercial fiber coated with divinylbenzene/polydimethylsiloxane (DVB/PDMS) was used for comparative studies. The results obtained showed that PCL is an interesting sorbent which can be successfully applied for isolation of polar organics from aqueous matrices at a broad range of analytes concentration. The determined detection limits of procedure based on the novel fiber enable its application at the concentration levels of triazines recommended by the US EPA standards. The practical applicability of the developed fiber has been confirmed by the results based on the analysis of real samples.

Processing and properties of a solid energy fuel from municipal solid waste (MSW) and recycled plastics

Diversion of waste streams such as plastics, woods, papers and other solid trash from municipal landfills and extraction of useful materials from landfills is an area of increasing interest especially in densely populated areas. One promising technology for recycling municipal solid waste (MSW) is to burn the high-energy-content components in standard coal power plant. This research aims to reform wastes into briquettes that are compatible with typical coal combustion processes. In order to comply with the standards of coal-fired power plants, the feedstock must be mechanically robust, free of hazardous contaminants, and moisture resistant, while retaining high fuel value. This study aims to investigate the effects of processing conditions and added recyclable plastics on the properties of MSW solid fuels. A well-sorted waste stream high in paper and fiber content was combined with controlled levels of recyclable plastics PE, PP, PET and PS and formed into briquettes using a compression molding technique. The effect of added plastics and moisture content on binding attraction and energy efficiency were investigated. The stability of the briquettes to moisture exposure, the fuel composition by proximate analysis, briquette mechanical strength, and burning efficiency were evaluated. It was found that high processing temperature ensures better properties of the product addition of milled mixed plastic waste leads to better encapsulation as well as to greater calorific value. Also some moisture removal (but not complete) improves the compacting process and results in higher heating value. Analysis of the post-processing water uptake and compressive strength showed a correlation between density and stability to both mechanical stress and humid environment. Proximate analysis indicated heating values comparable to coal. The results showed that mechanical and moisture uptake stability were improved when the moisture and air contents were optimized. Moreover, the briquette sample composition was similar to biomass fuels but had significant advantages due to addition of waste plastics that have high energy content compared to other waste types. Addition of PP and HDPE presented better benefits than addition of PET due to lower softening temperature and lower oxygen content. It should be noted that while harmful emissions such as dioxins, furans and mercury can result from burning plastics, WTE facilities have been able to control these emissions to meet US EPA standards. This research provides a drop-in coal replacement that reduces demand on landfill space and replaces a significant fraction of fossil-derived fuel with a renewable alternative.

Effectiveness of selected wastewater treatment plants in Yemen for reduction of faecal indicators and pathogenic bacteria in secondary effluents and sludge

The aim of this study was to evaluate the efficiency of wastewater treatment plants (WWTPs) in Yemen for reduction of faecal indicators and pathogenic bacteria in the secondary effluents and sludge. Hundred sixty bacterial isolates were obtained from 27 secondary effluents and sludge samples generated from Ibb wastewater treatment plant (IWWTP), Taiz wastewater treatment plant (TWWTP), Aden wastewater treatment plant (AWWTP1 and 2) and Sana'a wastewater treatment plant (SWWTP) in Republic of Yemen. Isolation of the bacteria was carried out by the direct plate method on the several selective media. The concentrations of faecal coliforms (FCs) were more than that recommended by World Health Organisation guidelines in all secondary effluents samples expect for those collected from TWWTP. FCs in the sludge from IWWTP and SWWTP were more than the standards limits recommended by United State Environmental Protection Agency (U. S. EPA) Class B, while sludge from AWWTP and TWWTP meet U. S. EPA standards limits Class A and class B, respectively. Among 160 bacterial isolates, E. coli was the most common (detected in 88.88% of the samples), followed by Streptococcus faecalis (70.37%), Klebsiella pneumonia (66.67%), Enterobacter aerogenes (59.23%), Salmonella typhi (33.33%), S. typhimurium and Shigella sonni (25.93% for each) and Yersinia pestis (22.22%). The sludge samples collected from IWWTP and TWWTP and stored for 24 weeks at room temperature (25 ± 2 °C) met the standards limits recommended by U.S. EPA, Class A.

Assessment of organic and heavy metal contaminants as a function of urban development near rivers of Puerto Rico (1143.9)

Anthropogenic activities, such as urbanization, manufacture, agriculture and transportation, often lead to contamination of water resources through runoff from sewer systems or illegal dumping. We wish to determine if urbanization near rivers in Puerto Rico results in increased levels of organic and metal contaminants of anthropogenic origin, to then test how these may affect behavior and nervous system function of river fauna. Water samples from two urban rivers with differing hydrological flow characteristics, Rio Piedras and La Plata, and a control non‐urban river, Rio Mameyes, were analyzed with Gas Chromatography‐Mass Spectrometry and Atomic Absorption Spectroscopy. A wide range screening of organic compounds (OC) identified 35 contaminants in the urban rivers, including esters, phthalates, pharmaceuticals and ingredients in personal care products. Dibutyl phthalate, commonly used in plastics and cosmetics, was found in La Plata at a concentration five times higher than the limit allowed by the EPA for drinking water. Copper, chromium and cadmium in the urban rivers are within EPA standards, although copper in the Río Piedras increased consistently from its origin to its lower reach, while remaining constant throughout the length of La Plata. Further experiments to measure other heavy metals and OCs from pharmaceuticals and personal care products are being conducted.Grant Funding Source: Supported by: NSF HRD‐1137725; NIH NIGMS R25GM061838; NIH NIGMS 5SC3GM084763

Genesis of antibiotic resistance (AR) III: trifling risk of AR pathogens induced infectious diseases from regulated concentrated animal feeding operations (986.3)

Concentrated Animal Feeding Operations (CAFOs) are sites where animals are housed and raised in a confined environment. CAFOs assemble animals that are fed and cared for by professional care givers referred to as “Cowboys” on a limited space in a rustic landscape. The operation is monitored and meets the standards set forth by The United states Environmental Protection Agency (http://www.epa.gov/region7/water/cafo/). In southwestern Texas, cattle are imported from Mexico, and subjected to the health inspection by The United States ‐ Mexico border USDA‐APHIS‐VS stations. Cattle undergo rigorous inspections for Tuberculosis, tick‐borne infections, and respiratory illness, along with prior health records followed by consignment to CAFOs (Feed Lots). While in Feed lots, the health and well being of the cattle is monitored by the house staff and also by USDA veterinarian. The amount of “Antibiotics” supplemented in the cattle feed is regulated by the EPA standards and followed through by in house nutritionist. MICRO BEEF TECHNOLOGIES, Ltd (http://www.microbeef.com/about_micro/index.html ) provides an excellent tracking system to maintain comprehensive details on individual animals regarding their health and nutrition. Taken together with an exceptional monitoring programs by The US‐EPA, USDA‐APHIS‐VS, and strict industry standards upheld by The Texas Cattle Feeders Association, the CAFOs pose minimal risk of rendering AR pathogen affected infectious diseases. (Acknowledgement: Dr. Darrell Haney, USDA‐APHIS‐VS, (830) 752‐1785, Eagle Pass, Texas; Mr. Luis De La Cruz, Runnells‐Peters Feed Yard LLC, 1444 Fm 1665, Quemado, TX 78877‐7790; Information Resources from Texas Cattle Feeders Association, http://www.tcfa.org/SiteMap.html).Grant Funding Source: Professional Development Funds ‐ SWTJC, Eagle Pass, Texas 78852

Combined Sewer Overflows (CSOs) Impact on Water Quality and Environmental Ecosystem in the Harlem River

The Harlem River, a 9.3-mile channel that flows from the Hudson River to the East River, has experienced decades of industrial abuse and remains gritty and industrial. During heavy rains, the pipes discharge raw sewage into the river through combined sewer overflows (CSOs) that can contain bacteria and cause illness. Water samples were collected from CSO discharge point and several adjacent sites along the river in the Bronx side close to River Park Towers at Richman Plaza and Manhattan side at Wards Island. Nutrients, bacteria, polychlorinated biphenyls (PCBs), and fish consumption safety have been analyzed. Results showed that phosphorus, ammonia concentration as well as fecal coliform, E.Coli, enterococcus levels increased significantly during heavy rainstorms. Ammonia concentration was up to 2.725 mg/L during tropical storm Arthur on July 2, 2014 and rainstorm in May 2013, and soluble reactive phosphorus (SRP) or orthophosphate was up to 0.197 mg/L during heavy thunderstorm in April 2011; both nutrients were exceeded EPA regulation for ammonia (0.23 mg/L) and phosphate (0.033 mg/L) for New York City (NYC) waters. The colonies of fecal coliform were more than 5 million MPN/100ml (most probable number per 100 ml) during tropical storm Arthur in July 2014 and heavy rainstorm in April 2014, and fecal coliform was more than 10,000 MPN/100ml during storm in July and November 2013; E.Coli reached more than 5000 MPN/100ml during tropical storm Arthur and storm in May 2013; enterococcus reached more than 10,000 MPN/100ml during tropical storm Arthur and heavy rainstorm in April 2014. These bacteria (pathogen) levels in the Harlem River were significantly higher than EPA standards (fecal coliform: 200 MPN/100ml, E.Coli: 126 MPN/100ml, enterococcus: 104 MPN/100ml), especially during rainstorm/tropical storm. Of particular significance, nutrients and bacteria were analyzed before and after Hurricane Sandy devastated NYC in late October 2012; results determined that bacteria and ammonia concentrations increased after this monumental storm, elucidating the environmental impact of large storm events. PCB 11 (3,3’-dichlorobiphenyl,

A Survey of the Heavy Metals Present in the Soil of a Potential Urban Garden: A Service Learning Approach

ABSTRACT Eight soil samples were collected from a small urban land plot located at 1700 North Sixth Street Harrisburg, PA 17102 and the concentration of copper, nickel, zinc, and lead in existing soil was determined. The concentrations of these metals were compared to EPA standards to assess soil suitability for the development of a successful urban garden. Samples were prepared by acid digestion and then analyzed using atomic absorption spectroscopy (AAS). The concentration of copper was found to be 11 ± 4 mg/kg at the low end and 46 ± 25 mg/kg at the high end, nickel concentrations ranged from 11 ± 4 mg/kg to 20 ± 3 mg/kg, lead concentrations from 26 ± 1 mg/kg to 402+ mg/kg, and the zinc concentrations ranged from 30 ± 6 mg/kg to 216 ± 166 mg/kg. All concentrations, with the exception lead, were below the EPA recommended limits for heavy metals in home and vegetable gardens. This study also discusses the benefits of service learning for developing relationships between academic institutions and community partners as well as the role of Community Supported Agriculture (CSA) in urban areas.

Higher surface ozone concentrations over the Chesapeake Bay than over the adjacent land: Observations and models from the DISCOVER-AQ and CBODAQ campaigns

Air quality models, such as the Community Multiscale Air Quality (CMAQ) model, indicate decidedly higher ozone near the surface of large interior water bodies, such as the Great Lakes and Chesapeake Bay. In order to test the validity of the model output, we performed surface measurements of ozone (O3) and total reactive nitrogen (NOy) on the 26-m Delaware II NOAA Small Research Vessel experimental (SRVx), deployed in the Chesapeake Bay for 10 daytime cruises in July 2011 as part of NASA's GEO-CAPE CBODAQ oceanographic field campaign in conjunction with NASA's DISCOVER-AQ air quality field campaign. During this 10-day period, the EPA O3 regulatory standard of 75 ppbv averaged over an 8-h period was exceeded four times over water while ground stations in the area only exceeded the standard at most twice. This suggests that on days when the Baltimore/Washington region is in compliance with the EPA standard, air quality over the Chesapeake Bay might exceed the EPA standard. Ozone observations over the bay during the afternoon were consistently 10–20% higher than the closest upwind ground sites during the 10-day campaign; this pattern persisted during good and poor air quality days. A lower boundary layer, reduced cloud cover, slower dry deposition rates, and other lesser mechanisms, contribute to the local maximum of ozone over the Chesapeake Bay. Observations from this campaign were compared to a CMAQ simulation at 1.33 km resolution. The model is able to predict the regional maximum of ozone over the Chesapeake Bay accurately, but NOy concentrations are significantly overestimated. Explanations for the overestimation of NOy in the model simulations are also explored.

Metal and pesticide pollution scenario in Ganga River system

The River Ganga passes through a large number of cities, towns, villages and agricultural fields. A sizable fraction of effluents and sewages generated from all these diverse sectors enters into the river. The incoming water is, therefore, carrying huge amounts of organic substances, residues of the used pesticides and metals along with other contaminants. Review of the pesticide residue studies indicate that hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and endosulfan were the major contaminants in water and biota while HCH, DDT, aldrin and dieldrin dominate the sediment phase. In water the residues are frequently crossing the permissible limits of US EPA standards for aquatic organisms and their consumers, indicating various levels of risk. In fishes, the permissible limits for HCH, endosulfan and DDT are exceed only in some occasions, signifying minor risks on human consumption. Regarding metal contaminations, the uppermost stretch, up to Haridwar, is relatively free from pollutions. The middle stretch, receiving diverse kinds of effluents, is markedly polluted. Although a significant stretch of the estuarine zone is densely industrialized and regularly receives effluents, the tidal action is maintaining the metals in lower level than the middle stretch. However, in majority of the cases the reported levels in water were much higher than the US EPA permissible limits for aquatic organisms. With respect to the metal contaminations in sediments, the river is found moderately polluted. In some fishes, contamination of Pb, Hg and Cr crosses the limits. However, the alkaline pH, high sediment transportation and rigorous flushing during monsoons are protecting the river from accumulation of these toxic contaminants. With respect to aquatic health, it is anticipated that the metal and pesticide contaminations might have adversely affected fish health. Systematic studies are, however, lacking on this aspect.

Performance of a biofilter system with agave fiber filter media for municipal wastewater treatment

Agave plants grow in semi-arid regions and are used for mescal production. However, agave fiber by-products are considered waste materials. Thus, we tested agave fiber as a filter media and biofilm material carrier for removing pollutants from municipal wastewater. Three laboratory-scale biofiltration reactors were used in two trials with five hydraulic loading rates (HLRs = 0.27, 0.54, 0.80, 1.07 and 1.34 m(3) m(-2) d(-1)). One series was conducted using mechanical aeration (0.62 m(3) m(-2) h(-1)). To prevent compaction, decreasing pressure and clogging of the filter media, 4, 8 and 12 internal divisions were evaluated in the biofilter column. After 17 months of continuous operation at an HLR of 0.80 m(3) m(-2) d(-1), the removal efficiencies of the aerated biofilters were 92.0% biochemical oxygen demand, 79.7% chemical oxygen demand, 98.0% helminth eggs, 99.9% fecal coliforms and 91.9% total suspended solids. Statistical analysis showed that the chosen operational parameters significantly influenced the removal efficiencies of the biofilters. The effluent quality obtained under these conditions complied with the Mexican and US EPA standards for agricultural irrigation and green spaces, except for coliforms, which is why the effluents must be disinfected. Thus, agave fiber is a favorable choice for use as a packing material in biofiltration processes.

Study on the heavy metal bioconcentrations of the Shadegan international wetland mosquitofish, Gambusia affinis, by inductively coupled plasma technique

The purpose of this study was to evaluate the levels of heavy metal bioconcentration of the mosquitofish (Gambusia affinis) in Shadegan international wetland. Sampling including the water, waterbed sediment and mosquitofish was carried out from the selected sampling sites during October and November 2011, and analyzed by the ICP-OES. Results show that the water has poor qualitative condition, according to EPA and WHO water quality standards. The level of the water Cr in the selected sites in both months and the levels of Fe, Mn and Zn during October in the SW1 site were higher than the instrumental detection limits indicating that the water was contaminated with these metals in the mentioned sites and months. The levels of the waterbed sediment As, Co, Cr, Cu, Fe, Mn, Pb and Zn, and mosquitofish Cr, Cu, Fe, Mn, Zn, Co and Cd were much higher than the instrumental detection limits, indicating that the waterbed sediment and mosquitofish were contaminated with them during October and November in the selected sites. Statistical assessments reveal that there is a significant difference between the mentioned contaminated water, waterbed sediment and mosquitofish heavy metals (all P-values < 0.05). In overall, it is considered that the contaminated heavy metals can be accumulated in the waterbed sediment and bioconcentrated in the wildlife tissues, then finally can be entered in the marine food chains and biomagnified there after long periods. In conclusion, this paper confirmed that the G. affinis can be used as a bioindicator of heavy metal pollution in marine ecosystems such as wetlands.

Greenhouse gas emission measurement and economic analysis of Iran natural gas fired power plants

This study attempts to examine the natural gas fired power plants in Iran. The required data from natural gas fired power plants were gathered during 2008. The characteristics of thirty two gas turbine power plants and twenty steam power plants have been measured. Their emission factor values were then compared with the standards of Energy Protection Agency, Euro Union and World Bank. Emission factors of gas turbine and steam power plants show that gas turbine power plants have a better performance than steam power plants. For economic analysis, fuel consumption and environmental damages caused by the emitted pollutants are considered as cost functions; and electricity sales revenue are taken as benefit functions. All of these functions have been obtained according to the capacity factor. Total revenue functions show that gas turbine and steam power plants are economically efficient at 98.15% and 90.89% of capacity factor, respectively; this indicates that long operating years of power plants leads to reduction of optimum capacity factor. The stated method could be implemented to assess the economic status of a country’s power plants where as efficient capacity factor close to one means that power plant works in much better condition. • CO 2 and NO x emissions of Iran natural gas fired power plants have been studied. • CO 2 and NO x emission factors are compared with EPA, EU and World Bank standards. • Costs and benefit as economic functions are obtained according to capacity factor. • Maximum economic profit is obtained for gas turbine and steam power plants. • Investment in CO 2 reduction is recommended instead of investment in NO x reduction.

대학가 주변 원룸의 라돈(radon) 농도 평가

Objective: Building materials can generate radon in indoor environments. This study aims to assess the radon concentrations of studio apartments around a university. Methods: 25 studio apartments around a University in Gyoungsan, Korea were measured for concentrations of radon. We evaluated the radon concentrations by using short-term continuous radon monitors at the studio apartments around the university, and analyzed the correlation between indoor radon concentration and factors affecting it, such as year of construction. Results: The average concentration of radon was 2.03 pCi/L(75.11 <TEX>$Bq/m^3$</TEX>)<TEX>${\pm}1.34$</TEX> in the studio apartments. This radon level was lower than the radon standard for public use facilities in Korea and US EPA's standard of 4 pCi/L. However the measured radon levels were much higher than those previously reported in conventional dwellings. There was a statistically correlation between year of construction and radon concentrations in studio apartment buildings. Conclusion: It is suggested that recently built studio apartments might be constructed with phosphogypsum board that features higher radon emissions, and occupants are highly exposed to radon.

Physico-chemical and Escherichia coli assessment of selected sachet water produced in some areas of Minna, Niger State, Nigeria

Access to good quality drinking water in Minna and, indeed, other parts of Niger State is one of the biggest challenges to many households which have, for years, depended on other sources of water to augment the erratic supply made by the government. In an effort to ensure adequate supply, packaged water has been introduced to provide safe, hygienic and affordable drinking water. However, trends have implicated some packaged water as agents of disease transmission. In this work, the physicochemical and coliform analyses of selected packaged water, otherwise called “pure water” were carried out. Ten brands were collected from the packaging factories (5 samples per brand) and were analysed weekly for four weeks. Results obtained were compared with WHO and EPA standards for drinking and recreational water. Their pH values, except for Sabo Best (6.26 ± 0.02), were within the stated WHO/EPA standards (6.50 - 8.50). The coliform levels of FUTMin (75.00 ± 2.00), Happy Days (75.00 ± 2.00) and Carry More (23.33 ± 0.33), based on the most probable number (MPN), were unfit for potability since they could also contain other microorganisms implicated in gastro-intestinal water borne diseases. The respective 1.63 ± 0.10 and 1.54 ± 0.10 mg/dm3 for Evershine and Supreme waters were above the 0.3 mg/dm3 iron standard just as the respective copper and nitrate values of 1.19 ± 0.14, 1.27 ± 0.10, 1.48 ± 0.10 and 86.81 ± 0.62, 124.47 ± 1.36, 141.70 ± 0.00 mg/dm3 for Golden Age, Supreme and Sabo Best were higher than the respective 1 and 50 mg/dm3 standards for copper and nitrates. All other parameters were within the EPA and WHO values. Key words: Packaged water, coliform, Escherichia coli, most probable number (MPN), potability, gastro-intestinal.

Estudio del impacto en la calidad del aire de las fuentes puntuales en la ciudad de pinar del Río

Se realizó un estudio del impacto de las fuentes fijas en la Ciudad de Pinar del Río utilizando el sistema de modelación MM5-CALMET-CALPUFF. Se simuló la dispersión de SO2, NOx, PM25, PM10 y CO emitidos por las 21 fuentes durante 15 días representativos del período lluvioso, además de la depositación húmeda de SO4(2-) y NO3-. Se observó que las máximas concentraciones se producen en horarios de la mañana y noche. Se observó que producto de estas emisiones se ven afectados algunas zonas cercanas a la ciudad como Minas de Matahambre, San Juan y Martínez, Santa María, San Luis, El Corojo, Hermanos Saíz, Viñales, Pilotos, Consolación del Sur y las Ovas. Los valores de concentración medios diarios de NOx y SO2 sobrepasaron sus concentraciones máximas admisibles según la NC 39: 1999 y estuvieron por encima de los valores guías de la Organización Mundial de la Salud y los valores estándares EPA.

Effect of Treated Waste Water Irrigation on Plant Growth and Soil Properties in Gaza Strip, Palestine

This study investigated the effect of treated wastewater (TWW) irrigation on growth of Chinese cabbage and corn and on soil properties in Gaza Strip, Palestine. Chinese cabbage and corn were planted in winter and summer seasons respectively in a sandy soil. The experimental design was a randomized complete block using 2 treatments with 4 replicates. Soil samples were collected from 0.0-120 cm depths from all plots and analyzed for pH, electric conductivity (EC) and nutrient contents. The plants were irrigated with either TWW or fresh water (FW) fortified with NPK, while control used drip irrigation system. The biomass (total fresh weight of the plants) was used as an indicator of the plant yields. Concentration of heavy metals on plant leaves was determined by Inductive Coupled Plasma Analyzer (ICP) and was taken as an indicator of plant quality. Biomass of Chinese cabbage and corn grown in plots irrigated with TWW was higher than those grown in plots irrigated with FW. These results indicate the ability of TWW supplying the necessary nutrients for plant growth. Heavy metal content in plant leaves in all treatments (TWW and FW) was nearly similar and below EPA standards, indicating high quality of plants. Soil analysis showed great changes in soil properties due to irrigation with TWW. The interesting outcome of this study is that TWW is an effective source for plant nutrients. It is encouraging to reuse TWW in agricultural system after full treatment.

Physico-Chemical and Bacteriological Analysis of Eripa and ErinIjesa Waterfalls used for Drinking & Recreational Purposes in Osun State, Nigeria.

Physico-chemical and bacteriological analysis of the two water falls were carried out. The results obtained were compared with EPA and WHO standards for drinking and recreational water. The water sources were within the standard set for pH, Total dissolved solids, Total solid, acidity, chloride and iron contents. For bacteriological analysis, the two samples did not comply with bacteriological standards because the total coliforms could higher than 1,300 MPN/ml, Vibrio cholerae counts and Salmonella - Shigella counts were also high. The pathogens in water for drinking and recreational purposes may pose a threat in public health and even other microorganisms that may also be present. The pathogens and other microbes are all concerned in gastro-intestinal water source diseases that usually affect man and aquatic lives at large.

Spatial and Temporal Variation of Total Nitrogen and Total Phosphorus in Major River Systems of Sundarbans Mangrove Forest, Bangladesh

Mangrove provides a unique ecological environment for diverse communities and Sundarbans is a rapidly changing ecosystem due to various anthropogenic activities. In order to assess the spatial and temporal variation of total Nitrogen and total Phosphorus concentration in Major River Systems of Sundarbans, a study was carried out from September, 2010 to February, 2011. Fourteen sampling location from major river systems were chosen. During post monsoon and winter seasons the range of total Phosphorus (0.326-0.409 mg/L and 0.091-0.371 mg/L respectively) and total nitrogen (2.52-3.50 mg/L and 3.43-5.25 mg/L respectively) were observed in Rupsha - Passur river system. On the other hand the range of total Phosphorus (0.475-0.144 mg/L and 0.060-0.113 mg/L respectively) and total nitrogen (2.31-3.61 mg/L and 3.22- 5.95 mg/L respectively) were found in Arpangashia - Malancha river system during post monsoon and winter seasons. The nutrients of water of Baleswar- Bhola river system during rainy and dry seasons were found in the range of total Phosphorus (0.106-0.364 mg/L and 0.053-0.075 mg/L respectively) and total nitrogen (2.59-3.57 mg/L and 2.87-5.60 mg/L respectively). Total Nitrogen and total phosphorus levels were relatively higher than the EPA standards for surface water during the two seasons. The Dynamic nutrients level observed in the study area may have severe consequences on the in-dwelling aquatic flora and fauna.

DETERMINATION OF CHLORFENVINPHOS, FIPRONIL, AND CYPERMETHRIN RESIDUES IN MEAT AND BOVINE FAT USING QUECHERS METHOD AND GAS CHROMATOGRAPHY-MASS SPECTROMETRY

Analytic methods were applied and validated to measure residues of chlorfenvinphos, fipronil, and cypermethrin in meat and bovine fat, using the QuEChERS method and gas chromatography-mass spectrometry. For the meat, 2 g of sample, 4 mL of acetonitrile, 1.6 g of MgSO4, and 0.4 g of NaCl were used in the liquid-liquid partition, while 80 mg of C18, 80 mg of primary and secondary amine and 150 mg of MgSO4 were employed in the dispersive solid-phase extraction. For the fat, 1 g of sample, 5 mL of hexane, 10 mL of water, 10 mL of acetonitrile, 4 g of MgSO4, and 0.5 g of NaCl were used in the liquid-liquid partition and 50 mg of primary and secondary amine and 150 mg of MgSO4 were used in the dispersive solid-phase extraction. The recovery percentages obtained for the pesticides in meat at different concentrations ranged from 81 to 129% with relative standard deviation below 27%. The corresponding results from the fat ranged from 70 to 123% with relative standard deviation below 25%. The methods showed sensitivity, precision, and accuracy according to EPA standards and quantification limits below the maximum residue limit established by European Union, except for chlorfenvinphos in the fat.