Grab Sampling Technique Research Articles

Can Reuse of Stormwater Detention Pond Water Meet Community Urban Agriculture Needs?

Urbanization and population growth in coastal communities increase demands on local food and water sectors. Due to this, urban communities are reimagining stormwater pond infrastructure, asking whether the stormwater can be used to irrigate food and grow fish for local consumption. Studies exploring this feasibility are limited in the literature. Driven by a community’s desire to co-locate community gardens with stormwater pond spaces, this research monitored the water quality of a 23.4-hectare stormwater pond located in East Tampa, Florida over one year using the grab sample technique and compared the results with U.S. Environmental Protection Agency (EPA) reuse recommendations, EPA national recommended water quality criteria for aquatic life, and human health. pH and conductivity levels were acceptable for irrigating crops. Heavy metal (arsenic, cadmium, copper, lead, and zinc) concentrations were below the maximum recommended reuse levels (100, 10, 200, 5000 and 2000 µg/L, respectively), while zinc and lead were above the criteria for aquatic life (120 and 2.5 µg/L, respectively). E. coli concentrations ranged from 310 to greater than 200,000 MPN/100 mL, above the 0 CFU/100 mL irrigation requirements for raw food consumption and 200 CFU/100 mL requirements for commercial food processing. Synthetic organic compounds also exceeded criteria for human health.

Antimicrobial resistance profile of bacteria from hospital wastewater at two specialized hospitals in Bahir Dar city, Ethiopia

BackgroundThe high levels of antimicrobial consumption in hospitals contribute to the occurrence of antimicrobial resistant bacteria. Antimicrobial resistant bacteria and sub-lethal concentrations of antimicrobial metabolites can end up in hospital wastewater which can spread to the environment and to the community. However, information on the resistance profile of bacteria isolated from environments is not well studied. Thus, the main aim of this study was to determine the antibiotic resistance profile of bacteria from hospital wastewater in Bahir Dar City, Northwest Ethiopia.MethodA total of 70 hospital wastewater samples were collected from two comprehensive specialized hospitals using a grab-sampling technique. Bacteria were identified using colony morphology, Gram staining, and biochemical tests. The drug susceptibility test was performed using the Kirby-Bauer disc diffusion method on Muller-Hinton agar.ResultThe most dominant bacterial isolates from hospital wastewater were Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Citrobacter spp., Acinetobacter spp., Enterobacter spp., Klebsiella pneumoniae (K. pneumoniae), and Pseudomonas aeruginosa (P. aeruginosa). All K. pneumoniae and 52.4% (11/21) E. coli were resistant to ceftazidime (third-generation cephalosporin), while Citrobacter spp., Acinetobacter spp., and Enterobacter spp., were susceptible to ceftazidime. Likewise, S. aureus revealed 64% (16/25) resistance to erythromycin. Overall, 22.2% of bacterial isolates were multidrug resistant bacteria to the commonly prescribed antimicrobials.ConclusionHospital waste waters contain high prevalence of multiple drug-resistant bacteria, particularly the third-generation cephalosporin resistant K. pneumoniae and E. coli would be a big concern. Infection prevention and control practices with proper treatment of hospital wastewater before discharging should be in practice to contain the spread of drug-resistant bacteria from hospital to external environment.

Pesticides in surface and groundwater in three micro-basins of the São Lourenço River, state of Mato Grosso, Brazil: grab and passive sampling

ABSTRACT This study aimed to assess the occurrence of pesticides in São Lourenço River basin, next to soybean, corn and cotton plantation, using complementarily grab and passive sampling techniques. São Lourenço River is an important affluent of Paraguay River which run to the Pantanal, the greatest wetland in the world with high environmental importance to the region. Methods for determining pesticides retained in the solid phase of passive samples and grab samples were developed and validated, which showed good precision and accuracy for the determination of 30 and 34 pesticides, respectively. A total of 72 surface and 55 groundwater samples using grab sampling and 137 surface water passive samples using POCIS were collected over a 1-year period. Pesticides atrazine, azoxystrobin, carbendazim, carbofuran, cyproconazole, clomazone, chlorantraniliprole, chlorpyrifos, difenoconazole, malathion, and metolachlor were detected in the three types of samples. Eleven pesticides were detected at concentrations ranging from 0.0132 to 1.31 µg L−1 for grab samples (surface waters), 0.0132 to 0.986 µg L−1 in shallow groundwater and 0.0011 a 0.204 µg L−1 in surface waters using passive samplers. The passive sampling technique applied to surface water confirmed the presence of the 15 analytes detected by grab sampling, allowed the identification of another 7 pesticides which were not detected in grab samples, and increased the incidence of detection of the analytes. While at least one pesticide was detected in 34% of grab samples, in the POCIS samplers the detection frequency was 95%. POCIS also provided a better temporal understanding of contamination levels showing that the higher detections and concentrations occurred in the rainy period and the period of more intensive application. Therefore, passive sampling showed to be highly effective for detecting pesticides at low concentrations as a complement to grab sampling, indicating that the joint use of both sampling strategies provides consistent monitoring data.

Microplastic pollution in the North-east Atlantic Ocean surface water: How the sampling approach influences the extent of the issue

A lack of standardization in monitoring protocols has hindered the accurate evaluation of microplastic (MP) pollution in the open sea and its potential impacts. As sampling techniques significantly influence the amounts of MPs contained in the sample, the aim of this study was to compare two sampling methods: Manta trawl (size selective approach) and grab sampling (volume selective approach). Both approaches were applied in the open sea surface waters of the North-east Atlantic Ocean. Onshore sample processing was carried out using the innovative tape lifting technique, which affords a series of advantages, including prevention of airborne contamination during analysis, without compromising integrity of the results. The results obtained indicated an MP concentration over four orders of magnitude higher using grab sampling compared to the Manta net approach (mean values equal to 0.24 and 4050 items/m3, respectively). Consequently, the sole quantification of MPs using results obtained with the Manta trawl resulted in a marked underestimation of abundance. Nevertheless, the grab sampling technique is intricately linked to a risk of collecting non-representative water volumes, consequently leading to an overestimation of MPs abundance and a significant inter-sample variability. Moreover, the latter method is unsuitable for use in sampling larger MPs or in areas with low concentrations of MP pollution. The optimal sampling method therefore is dependent on the specific objectives of the study, often resulting in a combination of size and volume selective methods. The results of this study have the potential to contribute to the standardization of monitoring protocols for microplastics, both during the sampling phase and sample processing.

Assessment of surface and groundwater quality in Tikamgarh city, Madhya Pradesh, India

Surface water and groundwater are primary resources for communities living in arid and semi-arid regions. The expansion of industrial and agricultural practices has raised pressure on natural resources. Water quality assessment provides valuable information about potential of resources for intended uses. The correlation study was carried out on the physicochemical parameters of surface water and groundwater in the Tikamgarh city. The physicochemical parameters, such as pH, total dissolved solids (TDS), total hardness (TH), calcium (Ca2+), magnesium (Mg2+), total alkalinity (TA), sulphate (SO42-), fluoride (F-), iron (Fe), nitrate (NO3-), chloride (Cl-) and turbidity were analysed to determine correlation between parameters. The grab sampling technique was adopted to collect water samples from selected dug wells and reservoirs. The results of physicochemical parameters were fitted in the correlation coefficient equation to predict probable values of different parameters for selected locations. Results of the correlation study showed that calcium and TH are strongly correlated, followed by TH with chloride. However, Ca2+, TH, Cl-, TA, TDS, SO42-, and iron show a high correlation. The findings show that water quality can be managed by controlling TH and TDS concentrations through conventional and non-conventional treatment methods.

Combination of pozzolan and sawdust as biofilter for textile wastewater treatment

Background: Inappropriate management of textile wastewater results in environmental pollution. To counter this, biofilters or biofilm systems serve as alternatives. Biofilters work like a filter, with a media stack that aids in the filtration process. In this study, pozzolan and sawdust were used as media. The present study aimed to identify the difference in average color content, chemical oxygen demand (COD), and chromium of textile wastewater after passing through a single biofilter versus a combination biofilter. Methods: This study employs a post-test with a control design experimental research design. The research population is the total textile wastewater produced by the X industry located in Cimahi city, Indonesia. The grab sampling technique was employed to collect 30 L of textile wastewater for each treatment using both the single biofilter (composed solely of sawdust) and the combination biofilter (mixture of sawdust and pozzolan). Results: There are significant differences in color, COD, and chromium content averages between single and combined biofilter treatments, supported by P values of 0.012, 0.004, and 0.010. The single biofilter exhibited higher percentage reductions in color and chromium (14.25% and 90.83%, respectively) compared to the combination biofilter. In contrast, the combination biofilter achieved a remarkable COD reduction of up to 79.45%compared to the single biofilter. Conclusion: The results of the present study showed that the single biofilter had a higher capacity to remove color and chromium compared to the combination biofilter. Meanwhile, the combination biofilter was found to be more effective in removing COD compared to the single biofilter.

Enumeration of Pathogenic Bacteria from Automatic Teller Machine (ATMs) Keyboard, a Case Study of ATM Machine of Branch 448 Unity Bank Plc Jahun, Jahun Local Government, Jigawa State

This study investigated the pathogenic bacteria from automatic teller machine (ATMs) keyboards, a case study of ATM machine of branch 448 Unity Bank PLC Jahun, Jahun Local Government, Jigawa state. ATM is used by hundreds of people in a day in the world (including Nigeria). The grab sampling techniques were used to obtain the sample. The cultural, Gram stained and biochemically tests were conducted. A total of 100 samples were collected from the ATM keyboard in the study area in April 2022, Staphylococcus aureus has the highest prevalence of 48%, E. coli 43% and P. aeruginosa has the lowest prevalence of 9% in this study. Pathogenic bacteria such as E. coli; P. aeruginosa and S. aureus on the ATMs were isolated. The research work revealed that there is a relationship between the Automatic Teller Machines (ATMs) and the isolated pathogenic bacteria. A bowl containing sanitiser should be provided by the bank management at every ATM location so that users can disinfect their hands after using the ATMs and also ATM Cleaners should be employed by the bank management so that they can disinfect the metallic buttons at intervals using compatible disinfectants.

Ceramic passive samplers for determining pharmaceuticals and drugs of abuse in river and drinking water

An important challenge today is to efficiently monitor the presence of polar pharmaceuticals and drugs in surface and drinking waters to ensure its safeness. Most studies rely on grab sampling techniques, which enable the determination of contaminants at a given point and given time. In this study, we propose the use of ceramic passive samplers (CPSs) to increase the representativeness and efficiency of organic contaminant monitoring in waters. Firstly, we have assayed the stability of 32 pharmaceuticals and drugs and found that five of those compounds were unstable. Moreover, we evaluated the retention capabilities of three sorbents (Sepra ZT, Sepra SBD-L, and PoraPak Rxn RP) in solid-phase extraction (SPE) mode and found no differences in terms of recoveries for all three sorbents. We then calibrated CPSs using the three sorbents for the 27 stable compounds over 13 days, with a suitable uptake for 22 compounds with sampling rates between 0.4 and 17.6 mL/day, which indicates high uptake efficiency. CPSs with the Sepra ZT sorbent were deployed in river water (n = 5) and drinking water (n = 5) for 13 days. Some of the studied compounds occurred with a time-weighted concentration, for instance, of 43 ng/L for caffeine, 223 ng/L for tramadol or 175 ng/L for cotinine in river water.

Pollution Status of Sediment from a Remediated Crude Oil Produced Water Discharge Channel Using Various Indices

The Forcados Terminal effluent discharged channel was remediated about twenty years ago with recommendation for periodic assessment of the organic and inorganic contaminants in the area. Forcados Terminal is in Delta State, Nigeria. This study was carried out to evaluate heavy metals pollution status of sediments in the remediated crude oil effluent discharge channel. A total of sixteen sediments samples were collected from ten sampling locations using grab sampling technique in October 2019 (wet season) and February 2020 (dry season). Heavy metals were determined in all the samples using atomic absorption spectrophotometry after digestion with aqua regia. The results showed that the concentrations of the sediment samples (mg/kg) ranged from <0.01-0.05, <0.01-0.91, <0.01-3.46, 13.2-45.3, 14.7-64.1, 5.56-105, 3.10-108, 0.14-5.86, 78.8-289, 28.2-254 and 3529-7773 for Hg, As, Cd, Pb, Cr, Ni, Cu, V, Mn, Zn and Fe. Hg and As were generally not detected in the sediments. On the average, the geoaccumulation index of Cd in the sediments falls into the moderately polluted category while the geoaccumulation index of all the other metals falls into the practically unpolluted category. On the average, the Contamination/Pollution index (CPI) value of Cd was > 1 which indicates that the sediments were polluted with Cd but the CPI values of other heavy metals were < 1 which indicates that these sediments were contaminated with the other heavy metals.

EFEKTIVITAS RUMPUT BEBEK (Lemna minor) DALAM PENYISIHAN KADMIUM (Cd) DAN CHEMICAL OXYGEN DEMAND (COD) PADA LINDI TPA SAMPAH GAMPONG JAWA KOTA BANDA ACEH

Lemna minor plant have the ability to reduce pollutant levels in Landfill leachate. The use of Lemna minor in leachate treatment was considered effective in degrading Cd and COD pollutants. The objective of this study was to determine the effectiveness and absorption rate of Lemna minor in degrading heavy metal Cd and reducing COD levels in Gampong Jawa Landfill leachate. This study used the phytoremediation method on a laboratory scale, and the leachate sampling method used the grab sampling technique. In testing both parameters, two types of test variations were carried out. First, in Reactor I, it was carried out without using an aerator, and in Reactor II, the test was carried out with the addition of an aerator. For duration, the variations of retention time were used are the third, sixth, ninth, and 12th days. The weight of the Lemna minor were used in each reactor was 35 grams for a leachate volume of 5 Liters. The results showed that Lemna minor was able to reduce pollutant levels in the Gampong Jawa Landfill leachate with the most optimal proportion of 15.92% for the heavy metal Cd, and 94.68% for the organic pollutant COD. Treatment on the 12th day for tests carried out in reactors that have an aeration system was the most effective variation in reducing the levels of Cd and COD parameters.&#x0D; Keywords : Lemna minor, Landfill Leachate, Phytoremediation

Determination of Some Heavy and Precious Metals from Printed Circuit Board (PCB) from a Television Set by Atomic Absorption Spectrophometer

Aim: This research work aimed to determine the concentrations of some heavy and precious metals from printed circuit board (PCB) of a television set using Atomic Absorption Spectrophotometer (AAS) in order to identify elements with higher concentration as target source of raw materials for metal recovery.&#x0D; Study Design: Grab sampling technique was applied in this study. The study area was a refuse dumb site at computer village Ogbunabali, Port Harcourt.&#x0D; Place and Duration of Study: This study was carried out at computer village Ogbunabali, Port Harcourt, Rivers State, Nigeria between 2020 and 2021.&#x0D; Methodology: The metal fractions attached to the PCB were subjected to mechanical separation, placed inside a 75ml Kjeldahl flask and thereafter digested with a 20ml nitric acid (HNO3). The prepared sample was filtered, then made up to 100ml using distilled water and analysed using AAS (Shimadzu model AA6300).&#x0D; Results: The results showed the presence of some heavy metals such as: (Fe,0.0644mg/l, Pb, 0.0732mg/l, Cu,0.0627mg/l, Ni, 0.1076mg/l and Cd, 0.0001mg/l) in higher concentrations (apart from Cd) than the precious metals (Au, 0.0297mg/l, Pd, 0.0042mg/l, Ag, 0.0316mg/l and Li, 0.0019mg/l). This confirmed that the PCB which is an electronic waste was largely made up of heavy and precious metals.&#x0D; Conclusion: Metals can be determined effectively from electronic waste using HNO3 and AAS. It is therefore, recommended that proper recycling methods should be put in place in order to reduce the pollution caused by these electronic wastes.

Physicochemical Characteristics of Waterholes and Soil in a Wildlife Park: A Case Study of Old Oyo National Park, Nigeria

Analysing the physicochemical characteristics of water and soil in conservation areas gives information about their quality and the effective management strategies wildlife conservationists could adopt. The study assessed thephysicochemical characteristics of selected perennial rivers and soil samples in Old Oyo National Park, Nigeria. A totalof 24 composited surface water and 36 topsoil samples were collected using grab and random sampling techniques,respectively for four seasons (two dry and two wet) for two consecutive years (2017 and 2018). The samples were analysed for selected physicochemical characteristics using standard methods. Data collected were subjected to descriptive and inferential (ANOVA) statistics SPSS (version 20.0) at α0.05. The result showed that the mean values (in the water samples) of Total Suspended Solids (673.13±592.10) in dry season 2018, Total Solids (799.37±610.17) in dry season 2018, and Sulphate (469.34±354.94) in dry season 2017 were above the comparable WHO permissible limit while the mean values (in the soil samples) of total nitrogen (except dry season 2018), exchangeable Magnesium and Potassium (across all the seasons) were above the comparable critical limits. There were significant differences in all the physicochemical characteristics of water sampled [except pH (P=0.12), chloride (P=0.96) and BOD (P=0.86)] while organic carbon (P=0.047), organic matter (P=0.041), nitrogen (P=0.020), calcium (P=0.016), total exchangeable bases (P=0.009) and effective cation exchange capacity (P=0.033) in soils were significantly different across the seasons of sampling. The soil physicochemical parameters above comparable critical limits may have elicited from the impact of anthropogenic activities by the surrounding communities with possible implication on wild animal health in the park.

Comparison of POCIS and grab sampling techniques for monitoring PPCPs in vernal pools in central Pennsylvania

Active ingredients in pharmaceuticals and personal care products (PPCPs) can persist through wastewater treatment plants and be released into the environment where they can inadvertently pose risks to non-target organisms. Emerging contaminants (ECs), including PPCPs, are commonly detected in wastewater effluent. With the increasing beneficial re-use of treated wastewater globally, there is a need to understand how spray-irrigation activities affect the occurrence and persistence of ECs in the environment to which they are introduced. Here, we explore the impacts of wastewater spray-irrigation on nearby ephemeral wetlands (e.g., vernal pools) through the use of grab and Polar Organic Chemical Integrative Sampling (POCIS) techniques. This study sought to determine whether integrative sampling techniques are better suited than traditional grab sampling techniques in assessing the presence and concentrations of ECs in vernal pools by evaluating 34 ECs in six vernal pools in central Pennsylvania. Three pools were impacted by wastewater spray-irrigation activities and three were in a nearby forested area. Results of this study found that POCIS detected a wide range of 25 ECs (log Kow between −2.6 and 9.37) more or, in some cases, equally frequently, relative to grab samples. Additionally, grab samples were found to best capture short-lived elevated inputs of ECs (from irrigation events) while POCIS were found to best capture ECs that were present in vernal pools over a longer period of time (weeks to months). For ECs detected more frequently in grab samples, concentrations were higher compared to time weighted average aqueous concentrations estimated from POCIS. This study advances understanding of the potential impact of wastewater beneficial reuse on vernal pools and informs how best to monitor the presence of ECs in vernal pools using integrative and grab sampling techniques.

An Assessment of Dam Water Quality for Fish Production in Malkerns, Eswatini

The construction of dams always provided an opportunity to promote commercial fish farming. In a number of dams commercial operations could be sustainably accommodated. However, there is a lack of assessment in the water quality of these water bodies for their suitability for fish production, though water quality is a critical aspect for fish production. Dams can provide the water needed for various applications in arid and semi-arid environments. However, most of these water sources are polluted with pollution from various sources including agriculture. An experiment was carried out to assess the quality of the Malkerns Research Station Dam water for fish production. The water from the inlet and outlet of the dam were used as the treatment, which was replicated three times. The fish farming production water quality guidelines were used as a control. Sampling was conducted in the morning using the grab sampling technique to collect water from the dam. The samples were taken to the laboratory for testing. Data analysis was conducted using one-way ANOVA &nbsp;in SPSS version 2.0 computer software. The results reflected that the mean pH of the water in the inlet and outlet of the dam was 6.9 and 6.7, respectively, which was within the recommended pH water quality guideline (6.5 - 9.0) for fish production. The mean turbidity of the dam water ranged from 3.8 NTU to 5.6 NTU, which was below the recommended water quality guideline value of 25 NTU for fish production. The mean salinity of the dam water was 400 mg/L, which was within the recommended water quality guideline (0 – 600 mg/L) for fish production. The mean copper level of the water in the inlet and outlet of the dam was 0.016 mg/L and 0.006 mg/L, respectively, which was higher than the recommended water quality guideline value of 0.005 mg/L for fish production. Based on the heavy metals, it was concluded that the Malkerns dam water quality was not suitable for fish production.

85 Impacts of dietary profile on starch content and gelatinization in canine diets

Abstract Starch gelatinization of pet foods can be impacted by several factors, including moisture, retention time, and ingredients used. Starch gelatinization has been associated with effects on digestibility, but isn’t well studied in non-traditional canine diets. The objective of this research was to examine the impacts of dietary ingredient profile (traditional vs. non-traditional) and assess impacts to total starch content and starch gelatinization. Traditional diets (n = 10) utilizing meat-based ingredients including chicken, chicken byproduct meal, meat and bone meal and plant-based ingredients including rice, barley, oats, and corn were examined in comparison with non-traditional diets (n = 10) utilizing meat-based ingredients including alligator, buffalo, venison, kangaroo, squid, quail, rabbit, rabbit and salmon along with plant-based ingredients including tapioca, peas, chickpeas, lentils, potato, and pumpkin. Representative samples were collected via grab sample technique (5 samples/diet) and were assessed for total starch content as well as percent starch gelatinization. Variation between both diet types were assessed with a nonlinear regression using SAS 9.4. Significance was set at P &amp;lt; 0.05. Distribution of total starch content based on ingredient type (traditional vs non-traditional) reveal that mean total starch content is 15% higher in traditional diets as compared to non-traditional diets (P &amp;lt; 0.0001). Conversely, percent starch gelatinization was found to be 10% higher in non-traditional diets (P &amp;lt; 0.0001). Total starch content and percent gelatinization had a highly significant non-linear relationship (P &amp;lt; 0.0001). These novel data reveal important differences between starch content and gelatinization and could impact manufacturing processes for ingredient types as well as feeding recommendations.

183 Isoquinoline alkaloids increase apparent ileal digestibility of amino acids and crude protein and apparent total tract digestibility of crude protein by finishing pigs fed corn-soybean meal diets

Abstract An experiment was conducted to determine if the inclusion of a preparation of isoquinoline alkaloids (IQ) in corn-soybean meal diets fed to finishing pigs increases the apparent ileal digestibility (AID) of amino acids (AA) and crude protein (CP) and the apparent total tract digestibility (ATTD) of CP and gross energy. Twelve ileal cannulated barrows (BW: 77.2 ± 6.23 kg) were allotted to a triplicated 4 x 3 incomplete Latin square design with 4 diets and 9 replicates per diet. Diets were supplemented with either 0, 40, 80, or 160 mg/kg IQ and with 0.40% titanium dioxide as an indigestible marker. Each collection period lasted 14 d with d 1 through 10 as an adaptation to the diets, fecal samples were taken using the grab sampling technique on d 11 and 12, and ileal digesta were collected for 8 h on d 13 and 14. Data were analyzed using the Proc MIXED procedure of SAS. Contrast statements were used to determine linear and quadratic effects of including IQ in the diets. Results were considered significant at P ≤ 0.05 and considered a trend at 0.05 &amp;lt; P ≤ 0.10. Inclusion of IQ resulted in a quadratic increase (P &amp;lt; 0.05) in the AID of CP and AA in corn-soybean meal diets fed to finishing pigs, with the greatest digestibility values generally observed in the 40 mg/kg IQ treatment. Additionally, IQ resulted in a quadratic increase (P = 0.009) in the ATTD of CP, with the greatest digestibility observed in the 80 mg/kg IQ treatment. Therefore, it was concluded that supplementing corn-soybean meal diets with 40 or 80 mg/kg IQ may increase the AID of CP and AA and ATTD of CP by finishing pigs.

Ultrasonic wave as anti-bacteria of coliform in the Kahayan River, Palangka Raya, Indonesia

This study aims to utilize the use of ultrasonic waves that function as anti-bacterial coliforms in the Kahayan river water. Water sampling is done using the Grab Sampling technique using the Kemmerer Sampler tool, without changing the environmental conditions. Samples taken in May 2019. The application of ultrasonic waves is done by using frequency variations of 20 kHz, 30 kHz, 40 kHz, 50 kHz, and 60 kHz at 5 minutes to get the optimum frequency. Coliform test was carried out by the MPN method, with the stages of the estimation test, affirmation test, and colony calculation. MPN test results show that the use of ultrasonic as the optimum anti-bacterial at a frequency of 40 kHz, with an efficiency is 89.9%.

Assessment of Physicochemical and Microbiological Characteristics of Water Samples of Okomu National Park, Edo State, Nigeria

Water is very crucial for the survival and maintenance of most living organisms. The quality of water available for plant, animal or human use cannot therefore be compromised. This study therefore examined the physicochemical and microbiological characteristics of water samples in Okomu National Park, Edo State, Nigeria. Water samples were collected from four waterholes (three rivers and one stream) for two seasons (dry and wet) using grab sampling technique. These water samples were analysed for physicochemical [temperature, pH, total dissolved solid, electrical conductivity, total suspended solids, dissolved oxygen (DO), nitrate, chloride, phosphate, sulphate, biological oxygen demand (BOD) and chemical oxygen demand (COD)] and microbiological (total coliform and fungal counts) analyses using standard methods. Data collected were subjected to descriptive statistics and T-test at α0.05 and compared with WHO permissible limits. The result showed that the mean COD (both seasons) and BOD (dry season) were above the comparable WHO permissible limit while there was no significant difference in the values of all the physicochemical parameters across the seasons of sampling. Salmonella / Shigella and Staphylococcus aureus were observed to be absent while the total coliform and fungi counts were observed to be higher than the WHO permissible limit for drinking water. The detection of Escherichia coli in the water samples (except Arakhuan stream) is an indication of faecal contamination either of animal or human origin. There was significant difference in total heterotrophic bacteria (t=-4.936) and total coliform counts (t=-2.417) in the waters sampled. Constant monitoring of the waterholes and intensified sensitization of the surrounding communities on ecosystem conservation is needed to protect the park’s ecosystems.

The performance of diffusive gradient in thin film probes for the long-term monitoring of trace level total mercury in water.

The potential of diffusive gradient in thin film (DGT) as a long-term monitoring tool to assess trace level mercury (Hg) in surface waters was evaluated. A piston type DGT sampler and a plate-type device that could hold 15 DGTs were designed. The device contained piston type DGT samplers with varying diffusive gel thicknesses, that is, 0.5, 0.75, and 1.0 mm, respectively. Three DGT devices were deployed in a lake for 5 weeks, and two were deployed in a stream for 3 weeks. In the lake, the total Hg (THg) mass accumulated in the DGT varied between 0.05 and 0.15 ng, which increased with an increase in deployment time and decreased with an increase in agarose diffusion gel thickness. The DGT concentration in the lake water for a 2 week period was estimated to be about 0.8-1.0 ng/L, which was close to the measured value of 1.1 (± 0.13) ng/L, using the grab sampling technique. However, the DGT estimated at 4 and 6 weeks showed a concentration of about 0.5-0.7 ng/L, which is about twice as small as that measured by grab sampling. This underestimation of the THg levels in water appear to be caused by additional thicknesses of the physical diffusive boundary layer (0.15, 0.5, 1.29 mm) and biofilm, outside the DGT filter. The predicted DGT concentration in the upper stream of the Nakdong River was estimated to be about 0.8-1.4 ng/L, which is similar to the value of 1.22 (± 0.29) ng/L measured in the field by grab sampling. The concentration of THg was estimated to be about 1.0-1.2 ng/L, which is similar to the values measured by grab sampling. The additional diffusion thickness formed outside the DGT filter was 0.018 mm and 0.093 mm at 1 and 3 weeks, respectively, which is not larger than the diffusion gel thickness (0.5-1.0 mm). This was because DGT was installed in a region where the flow velocity is high, and the thickness of the diffusion boundary layer outside the filter is negligible.

Laju Deoksigenasi Dan Laju Reaerasi Sungai Bedadung Segmen Desa Gumelar Kabupaten Jember

Bedadung River is the main river in the Bedadung Watershed in Jember Regency. People use the river to fulfill their daily needs and agricultural irrigation. Organic pollutants from domestic wastewater and agriculture wastewater that enter in river can decrease dissolved oxygen concentration, which can influence the river’s water quality. The river has a self-purification system with a reaeration and deoxygenation mechanism. The purpose of this study was to analyze the rate of deoxygenation and reaeration using the Streeter-Phelps method. Deoxygenation and reaeration rates influence oxygen concentration. This research took water samples using a Grab Sampling technique as the primary data at 5 nodes and 4 segmentations. The results of the research showed that the deoxygenation rate was 0.036 mg/L.day and the reaeration rate was 0.046 mg/L.day. This meant that the deoxygenation rate was lower than the reaeration rate so the self-purification can run quite well. The average DO value was 7.62 mg/L, showed that the river according to the class III water quality standard, so, the water quality was good and save to be used by the public. The research result can be used to determine the water quality carrying capacity in the next research.