Fecal Coliforms Research Articles

Spatio-temporal dynamics of ecological, bacteriological, and overall water quality of the Damodar River, India.

Assessing river water quality is crucial for human and ecological needs because of the deterioration of the river and escalated water pollution under the threats of anthropogenic activities. In order to assess river water quality, the Damodar River water was evaluated from the perspectives of spatio-temporal dynamics of ecological (organic pollution index or OPI and eutrophication index or EI), bacteriological (coliform count and comprehensive bathing water quality index or CBWQI), and overall water quality assessments (water quality index or WQI and comprehensive pollution index or CPI). The OPI reveals that 44.66% of water samples have heavy organic pollution; however, EI depicts that almost all water samples of Damodar River have severe eutrophication, especially in the pre- and post-monsoon seasons. Moreover, the fecal coliform count and CBWQI indicate the unsuitability of river water for bathing. The overall WQI portrays that 21.56%, 33.59%, and 22.47% of water samples have heavy pollution in pre-monsoon, monsoon, and post-monsoon, respectively. Moreover, 73.39% of water samples have low CPI indicating slight comprehensive pollution. This study also reveals that the pollution level in the Damodar River downstream of the Durgapur barrage is high among the other stations. The major reasons behind the severe contamination of Damodar River water are urban-industrial and agricultural effluents mixing into the river that lead to higher concentrations of BOD, DO, fecal coliform, COD, fluoride TSS, and turbidity in the river water. Thus, this study carries appreciated information on policy recommendations for the different stakeholders of the Damodar River basin including regional planners, agri-engineers, and ecological river engineers for sustainable river management.

Impact of the Citrus Industry on the Water Quality of the Filobobos River in Veracruz, Mexico

Veracruz, Mexico, boasts abundant water resources. However, the region is facing challenges stemming from population growth and industrial expansion, leading to a notable increase in wastewater discharge into surface water bodies. This discharge has resulted in significant alterations to water quality. In this study, we analyzed the water quality in the Bobos River, Veracruz, with a focus on sustainability. A total of 12 samples were collected from various points along the reservoir. Parameters including temperature, pH, dissolved oxygen (DO), conductivity, total nitrogen (TN), nitrate, chemical oxygen demand (COD), total phosphorus (TP), phosphate, dissolved solids (DSs), and fecal coliforms (FCs) were measured and analyzed. The pH levels ranged from slightly acidic (6.40 ± 0.71) to slightly alkaline (8.65 ± 0.07), with the lowest dissolved oxygen concentration recorded at 0.15 ± 0.07 mg L−1. Conductivity varied between 0.26 and 3.81 mS. Total nitrogen concentrations ranged from 0.21 ± 3.8 to 0.491 ± 1.3 mg L−1. Dissolved solid concentrations were measured at 0.39 ± 0.05 mg L−1, while the final sampling point exhibited elevated values for temperature, nitrate, chemical oxygen demand, total phosphorus, and coliforms (30.35 ± 0.21 °C, 0.35, 389.00 ± 11.31, 13.20 ± 0.85 mg L−1, and 3.2 × 105 ± 3.707107 × 104, respectively). To address these concerning trends and safeguard public health and environmental integrity, the implementation of continuous monitoring and stringent control measures is imperative.

Assessment of toxicity and antimicrobial performance of polymeric inorganic coagulant and evaluation for eutrophication reduction

In this study, the efficacy of the promising iron—based polymeric inorganic coagulant (POFC) was assessed for the reduction of eutrophication effect (freshwater toxicity) and the microbial loads from wastewater. Toxicity assessment for POFC was conducted on mice and skin cell lines. The results confirm the lower toxicity level of POFC. The POFC showed excellent antibacterial efficacy against Gram-positive and Gram-negative bacteria. Moreover, it demonstrated a remarkable effectiveness against black fungus such as Aspergillus niger and Rhizopus oryzae. Additionally, POFC showed antiviral effectiveness against the highly pathogenic H5N1 influenza virus as well as Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). POFC-based treatment gives excellent removal percentages for phosphate, and phosphorus at doses below 60 ppm with a low produced sludge volume that leads to 84% decrease in the rate of eutrophication and freshwater toxicity. At a POFC concentration of 60 ppm, remarkable reduction rates for total coliforms, fecal coliforms, and E. coli were achieved. After POFC-based coagulation, the produced sludge retains a lower bacterial density due to the antibacterial activity of POFC. Furthermore, it revealed that the observed removal efficiencies for fungi and yeasts in the produced sludge reached 85% at a POFC dose of 60 ppm. Overall, our research indicates that POFC has potential for application in pre-treatment of wastewater and serves as an antimicrobial agent.

Effect of some physicochemical parameters on the decay rate of enteric bacteria isolated from River Owena, Nigeria

The significance of water in public health cannot be overemphasized. In Nigeria, many people living along the courses of water bodies still source and drink from the rivers and streams. There is, therefore, the need to determine the load of contamination and effect of pH and salinity on the decay rate of enteric bacteria in water samples from River Owena, Owena, Nigeria, in order to develop adequate water quality management. Water samples from River Owena were collected from three sampling points (inflow, middle course and the outflow) along the River Owena, Nigeria. The load of enteric bacteria in the water samples was enumerated using membrane filtration technique. The physicochemical parameters of the water samples were determined using standard methods. The incidence and prevalence of gastroenteritis in the community around River Owena was determined using a structured questionnaire. Microcosm studies were used to determine the decay rate of enteric bacteria at varying salinity and pH. Canonical correlation analysis was used to describe the relationship between the load of enteric bacteria and the incidence and prevalence of gastroenteritis in the community around River Owena. The incidence and prevalence of gastroenteritis in the community around River Owena were estimated to be 0.75 and 0.51, respectively. Escherichia coli had positive relationships with incidence (r = 0.76) and prevalence (r = 0.65). Similarly, faecal coliforms had positive relationships with incidence (r = 0.82) and prevalence of gastroenteritis (r = 0.67), while enterococci showed positive relationship with incidence (r = 0.59) and prevalence of gastroenteritis (r = 0.87). Increase in pH and salinity increased the decay rate of enteric bacteria thereby reducing the growth of enteric bacteria, the optimum pH for the growth and survival of enteric bacteria ranged between pH 5.0 and pH 7.0. The optimum salinity for the growth of enteric bacteria isolated in water samples from River Owena ranged between 10 and 50% salinity. Findings revealed high levels of faecal contamination at the different representative monitoring points on River Owena, pH and salinity influenced the load and decay rate of enteric bacteria in water from River Owena.

EVALUATION OF WATER POLLUTION STATUS OF TRIYUGA RIVER IN UDAYAPUR DISTRICT, NEPAL

The present investigation has been conducted to assess the status of physiochemical and microbiological parameters to understand the present scenario of water quality at Triyuga River water at Belaka municipality of Udayapur district, Nepal. The temperature ranged from 180C to 200C, the TDS value ranged from 89 mg/L to 112 mg/L and were below the WHO guideline value of 1200 mg/L, the pH values of the surface water sources in the present study were found to be alkaline ranging above from 7.6 to 7.9 were found within the range of WHO guideline value of 6.5-8.5. Similarly the values of dissolved oxygen ranged from 6.4 mg/L to 10.4 mg/L and were above the WHO guideline value of 5 mg/L, the bicarbonate (HCO3) value ranged from 105 mg/L to 125 mg/L and were below the WHO guideline value of 125-350 mg/L, the values of Nitrate ranged from 3 mg/L to 5 mg/L and were below the WHO guideline of 50 mg/L, the values of Nitrite ranged from 0.3 mg/L to 0.5 mg/L, the value of Ammonium ranged from 0 mg/L to 0.3 mg/L, the values of Iron ranged from 1 mg/L to 1.5 mg/L and were above the WHO guideline of 0.3 mg/L and the phosphate was not detected in all the three different sites of surface water samples. The fecal coliform was found to be positive in all the samples and the value of fecal coliform recorded was 15, 15 and 21 MPN/100ml in Site I, II and III respectively.

Flowing Through Change: Investigating the Impacts of Human Activities on Urban River Water Quality in the Kumba River, South West Region of Cameroon

This study seeks to examine the relationship between the different urban land use activities in the Kumba metropolis and the related implications on the Kumba river water quality. This involved collection of water samples from the Kumba river as well as performing laboratory tests to determine variations in the river's Physical, chemical and bacteriological properties. The parameters analyzed were temperature, dissolved oxygen, total dissolved solids, total suspended solids, Electrical Conductivity, odour, colour, turbidity, nitrite, nitrate, pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonia, phosphorus, chlorine, nitrates, nitrites and some heavy metals like copper, phosphate, iron, zinc, calcium, magnesium and Faecal Coliform. Water samples were collected from five sampling points in the month of February 2023(peak dry season) and in the month of April 2023(for the rainy season). The data from the analysis of the water samples were analyzed using both descriptive and inferential statistics, on both Microsoft Excel and SPSS. The study found that the p values were less than 0.05 at a confidence level of 95%, which suggests that the Kumba River is polluted due to the effects of different urban land use activities in the city. The water quality parameters of the collected samples showed that areas with high dependence on the river for urban activities registered significantly poor water quality, compared to samples with limited dependence on the river for urban land uses. Based on these findings, it is recommended that anthropogenic activities within the area be closely monitored as urbanization continues to rapidly occur and its effects continue to pollute the river, making it harmful not only to ecosystems but also rendering it unfit for river channel crop cultivation. Additionally, the study concluded that changes in Land Use Land Cover (LULC) between 2007 and 2023 have statistically significant effects on the physicochemical and microbial water quality of the Kumba River. Therefore, it is vital to address the rate at which forests are being converted to agricultural lands and the intense use of agrochemicals on these farms and plantations.

Water quality indexes and water quality population perception in a rural area in Ecuador

Abstract This studỳs aim was to evaluate the quality of water for human consumption in a rural area of Ecuador. For this purpose, two water quality indexes were used: the Water Quality Index (WQI) and the Simplified Water Quality Index (SWQI). Sampling campaigns were carried out during the years 2018 and 2019, and 18 parameters were analyzed, including pH, conductivity, dissolved oxygen, temperature, color, phosphates, nitrites, nitrates, biochemical oxygen demand, chemical oxygen demand, total suspended solids, turbidity, methylene blue active substances, fats and oils, total coliforms, ammonia, nitrogen, and fecal coliforms. The WQI and the SWQI yielded values between 79.80 and 81.31 (2018) and between 76.99 and 79.89 (2019), respectively. Multivariate statistical methods were applied to implement water management recommendations. The perception of water quality was assessed through a survey of the population. This study contributes to recommending a proposal for the adoption of a WQI in Ecuador. The obtained results indicate that the water in the studied area needs the conventional treatment to achieve adequate quality for human consumption.

Efecto antimicrobiano in vitro de aceite esencial de eucalipto (<i>Eucalyptus globulus </i>labill) y muña (<i>Minthostachys mollis</i>)

The objective of this research work was to evaluate the antimicrobial effect of 2 oil sources against Staphylococcus aureus and Fecal Coliforms. For the oil extraction, the steam drag method was applied where 5000g of sample was used (muña, Eucalyptus leaves), in which the yield presented: muña 50ml = 0.9268%, eucalyptus 52ml = 0.9717%, a Physicochemical characterization whose result was: in muña oil: peroxide index: 0.75 (Meq / Kg), Iodine index: 6.87 (IV), Acidity index: 1.78 (% FFA), Refractive index: 1.486 (n), density: 0.898 (Kg / L). In eucalyptus leaves: peroxide index: 0.68 (Meq / Kg), Iodine index: 8.08 (IV), Acidity index: 1.82 (% FFA), Refractive index: 1.495 (n), density: 0.845 (Kg / L). Inhibition halos were determined in millimeters (mm), with muña oil in dilutions at 25, 50 and 75% against Fecal Coliforms, where it was at 25%: 9.7950mm, 50%: 10.7467mm, 75%: 13.2700 mm, against Staphylococcus aureus, 25%: 9.9600mm, 50%: 10.7408mm, 75%: 13.1533mm; with dilution of Eucalyptus essential oil against Fecal Coliforms at 25%: 12.0983mm, 50%: 13.2900mm, 75%: 14.5875mm; then against Staphylococcus aureus in 25%: 11.7200mm, 50%: 13.5608mm, 75%: 14.3767. It was possible to establish the inhibitory effect in 2 sources of oils against Fecal Coliforms and Staphylococcus aureus, for which it is concluded that the more dilution of the oil, more microbial inhibition, these species have their respective active principles such as monoterpenes, alcohols, ketones and terpenic oxides that prevent microbial growth.

Characterization of Leachate and Evaluation of Groundwater Pollution in the Vicinity of the Municipal Solid Waste Landfill in Srinagar, Jammu & Kashmir

Abstract: The most popular way for disposing of municipal solid waste (MSW) throughout India, including Kashmir, is through landfills. However, the discharge of leachate from these facilities has seriously contaminated groundwater. An evaluation was conducted on the groundwater quality near the Srinagar landfill site (Achan). In order to investigate the potential effects of leachate percolation on groundwater quality, samples of leachate and groundwater were taken from the Srinagar dump site and its surrounding areas. Groundwater and leachate samples were used to measure the concentration of various physio-chemical parameters (pH, EC, TDS, COD, BOD, Ca2+, Mg2+, Na+, K+, Cl-, SO42-, NO3-, NH4+, PO43-, Phenol), as well as microbiological parameters (total coliform and faecal coliform) and heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Zn, and Hg). The relatively elevated levels of NH4+, EC, TDS, BOD, phenol, Cd, and Mg, Cr were above the limits of Indian standard and WHO for drinking water. In addition to this , these also represent heavy pollutant indicators as per the Single Point Pollution Index as well by the Nemero index, as these elements crossed the upper most limit for both these pollution indeces. Assessing the water contamination in depth and distance wise, closer to landfill and shallow wells were characterized as the most polluted and had some additive contaminants ( Cl- ,SO4, Ca , Ni ). This is an indication of pollution transfer and the leachate movement. The presence of total coliform and faecal coliform although in small counts warns for the groundwater quality and thus renders the associated aquifer unreliable for domestic water supply. There is no natural or other possible reason for high concentration of these pollutants, thus it can be concluded that leachate has significant impact on groundwater quality in the area. In the present study, also an attempt has been made to investigate physico-chemical properties, fertilizing potential and heavy metal polluting potentials of the three types of composts including municipal soild waste compost, green waste compost and mixed waste compost. Each of these types were given a treatment with effective micro organisms (EM) to understand the quality of compost so formed by the composting process by its analysis (Laboratory as well as statistical) and the quality of composts was found out using Quality control Indices such as Fertilizing Index and Clean Index. Parameters like, pH, EC, TOC, total nitrogen, total phosphorous, total potassium, C/N ratio, and heavy metals like zinc, copper, cadmium, nickel, lead, and chromium were analyzed and it was found that all the parameters were within the permissible limits prescribed by FCO-2000. Further Fertility Index and Clean Index were determined for the samples and it was found that proper segregation of the solid waste is important from composting point of view because mixed waste affects the quality of compost. From the calculated values for the compost prepared from untreated MSW, FI (3.40) and CI (2.8), for the treated MSW Compost, FI as 3.47 and CI as 3.0, for the untreated mixed waste FI (3.27) and CI (3.0) and for the treated mixed waste FI (3.47), CI (3.2) The determined values indicates that all these compost types belongs to marketable Class D (medium fertilizing potential and medium heavy metal content).The fertility index value was estimated as 2.0 and the Clean Index value as 3.06 for the untreated green waste while for treated green waste FI(2.73) and CI(3.7), which indicates that both compost types belongs to restricted use Class RU-1 (Should not be allowed to market due to low fertilizing potential. However, these can be used as soil conditioner)

Microbial Quality of Fresh Juices Sold by Street Vendors and Associated Human Health Risks: The Case of Ilala Ward, Dar es Salaam City, Tanzania

Microbial food quality serves to indicate health risks associated with the consumption of contaminated foods. This study aimed to determine the microbial quality of fresh juices and the level of awareness and perception of the consumers and juice vendors at Ilala Ward, Dar es Salaam. Fresh samples of sugarcane, mango and mixed fruit juices were collected from four different sampling stations and analysed using standard methods for Total Coliform (TC), Faecal Coliform (FC) and Total Viable Count (TVC). The level of awareness and perception of 60 juice vendors and 60 consumers were also assessed by using questionnaires. The results showed that TC numbers ranged from the lowest mean of 6.100±4.180x106 to 7.483±3.650x107 MPN/ml, FC ranged from 2.566±0.989x106 to 2.017±1.687x107 MPN/ml while TVC ranged from 5.046±1.032x109 to 5.871±0.835x109 CFU/ml of fresh juices. The level of TC, FC and TVC was beyond the recommended international and Tanzanian standards showing that fresh juices posed a high risk for consumers. On the other hand, 42% of the juice consumers had low awareness of microbial contamination of fresh juices, which leads to high health risks. It is recommended that street juice vendors should adopt proper hygiene measures and undergo appropriate training on microbial quality, food safety and sanitation.

Baku mutu kualitas air muara sungai di kawasan Pura Petitenget dan upaya pengendaliannya

The main objective of this research is to analyze the quality standards for the quality of flowing water and river estuaries in the Petitenget Temple Area and efforts to control pollution or reduce the quality standards for flowing and river estuary water in the Petitenget Temple Area. The research was conducted from December 2018 to April 2019 in the river that flows into Petitenget Beach by taking four sampling points. The quality of water quality standards is measured using the water quality standards of Bali Governor Regulation No. 16 of 2016 concerning Environmental Quality Standards and Standard Criteria for Environmental Damage. The results of the research found that the quality of the water quality standards in the Petitenget Temple area had experienced pollution, namely the parameters of turbidity, chemical oxygen demand (COD), biological oxygen demand (BOD5), phosphate (PO4-P), total ammonia (NH3-N), fecal coliform, and total coliform. Efforts that can be made to overcome pollution in Loloan waters and river estuaries in Petitenget are the creation of Waste Management Regulations through the 4R (Reuse, Reduce, Recycle, Replace) pattern, limiting the use of chemical fertilizers and pesticides, creating waste storage and processing (septic tanks), and involving traditional villages (based on traditional villages) as well as environmental law enforcement.

Reprocessing and Resource Utilization of Landfill Sludge—A Case Study in a Chinese Megacity

In the past, due to improper sludge treatment technology and the absence of treatment standards, some municipal sludge was simply dewatered and then sent to landfills, occupying a significant amount of land and posing a serious threat of secondary pollution. To free up land in the landfill area for the expansion of a large-scale wastewater treatment plant (WWTP) in Shanghai, in this study, we conducted comprehensive pilot research on the entire chain of landfill sludge reprocessing and resource utilization. Both the combination of polyferric silicate sulfate (PFSS) and polyetheramine (PEA) and the combination of polyaluminum silicate (PAS) and polyetheramine (PEA) were used for sludge conditioning before dewatering, resulting in dewatered sludge with approximately 60% moisture content. The combined process involved coagulation and sedimentation, flocculation, and oxidation to treat the leachate generated during dewatering. The treatment process successfully met the specified water pollutant discharge concentration limits for the leachate, with the concentration of ammonia nitrogen in the effluent as low as 15.6 mg/L. Co-incineration in a power plant and modification were applied to stabilize and harmlessly dispose of the dewatered sludge. The coal-generating system ran stably, and no obvious problems were observed in the blending process. In the modification experiment, adding 5% to 7% of the solidifying agent increased the sludge bearing ratio by 53% and 57%, respectively. This process effectively reduced levels of fecal coliforms and heavy metals in the sludge but had a less noticeable effect on organic matter content. The modified sludge proved suitable for use as backfill material in construction areas without requirements for organic matter. The results of this study provide valuable insights for a completed full-scale landfill sludge reclamation and land resource release project.

Disinfection of wastewater by a complete equipment based on a novel ultraviolet light source of microwave discharge electrodeless lamp: Characteristics of bacteria inactivation, reactivation and full-scale studies

Ultraviolet (UV) light is widely used for wastewater disinfection. Traditional electrode-excited UV lamps, such as low-pressure mercy lamps (LPUV), encounter drawbacks like electrode aging and rapid light attenuation. A novel UV source of microwave discharge electrodeless lamp (MDEL) has aroused attention, yet its disinfection performance is unclear and still far from practical application. Here, we successfully developed a complete piece of equipment based on MDELs and achieved the application for disinfection in wastewater treatment plants (WWTPs). The light emitted by an MDEL (MWUV) shared a spectrum similar to that of LPUV, with the main emission wavelength at 254 nm. The inactivation rate of Gram-negative E. coli by MWUV reached 4.5 log at an intensity of 1.6 mW/cm2 and a dose of 20 mJ/cm2. For Gram-positive B. subtilis, an MWUV dose of 50 mJ/cm2 and a light intensity of 1.2 mW/cm2 reached an inactivation rate of 3.4 log. A higher MWUV intensity led to a better disinfection effect and a lower photoreactivation rate of E. coli. When inactivated by MWUV with an intensity of 1.2 mW/cm2 and a dose of 16 mJ/cm2, the maximum photoreactivation rate and reactivation rate constant Kmax of E. coli were 0.63 % and 0.11 % h−1 respectively. Compared with the photoreactivation, the dark repair of E. coli was insignificant. The full-scale application of the MDEL equipment was conducted in two WWTPs (10,000 m3/d and 15,000 m3/d). Generally 2–3 log inactivation rates of fecal coliforms in secondary effluent were achieved within 5–6 s contact time, and the disinfected effluent met the emission standard (1000 CFU/L). This study successfully applied MDEL for disinfection in WWTPs for the first time and demonstrated that MDEL has broad application prospects.

Microbial evaluation of borehole water used by selected bakeries in Ijebu-North, Ogun State, Nigeria

Water is one of the most important components of dough systems used to produce bread and other bakery products. Water could serve as a direct or indirect source of microbial contamination during baking, handling, or packaging, thereby affecting the quality and safety of bakery products. This study investigated the presence of faecal coliforms in water sources of selected bakeries in Ijebu North Local Government Area. Water samples were collected from the main sources of three bakeries located in the Ijebu North Area. Physical and microbiological parameters were then investigated and compared to the WHO guidelines. The average temperature and pH ranged between 24.30 and 25.27oC and between 6.40 and 6.73, respectively. The average total bacterial and coliform counts of the water samples collected from the three bakeries were in the ranges of 1.80-3.60 x 104 CFU ml−1 and 1.60-2.70 x 104 CFU ml–1, respectively (p < 0.0001). Twenty-nine isolates comprising four species (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Salmonella spp.) were observed in this study. The study showed that all water samples under analysis were tainted with faecal coliform, which makes the water unsafe for use in bakeries.

Microwave Treatment of Three Different Types of Sewage Sludge Based on Their Solar Drying Exposure Time: Effect on Microorganisms, Water Content and Agronomic Aspects

This study aimed to treat sewage sludge through microwave irradiation at a laboratory scale. The objective was to investigate the effect of microwave irradiation on microorganisms, water content, organic matter, and agronomic nutrients present in sewage sludge. Three types of sewage sludges obtained from a full-scale wastewater treatment plant were considered: Sludge A (raw sludge), Sludge B (subjected to 15 days of solar exposure, achieving 48% dryness), and Sludge C (exposed to solar conditions and left open to the air for 23 months, reaching 94% dryness). These diverse sludges were exposed to microwave irradiation at various power levels (analysed variables: ε (Watts/g), θ (°C), T (min)). The specific exposure powers and temperature levels for the water reduction analysis were: 555, 955, 1355, and 1500 Watts/g and 55, 75, 95, and 105 °C, respectively. On the other hand, microbiological and agronomic nutrient analyses were conducted at 75 °C–1355 W and 95 °C–1355 W. After microwave exposure experiments, the results demonstrated the high effectiveness of microwave technology in eradicating indicator microorganisms of faecal contamination and reducing sludge volume while not affecting trace elements of significant agricultural value. The reduction in Escherichia Coli revealed that 4 min of irradiation was necessary to completely eliminate it to 0 ulog, indicating a 100% reduction, in Sludge A. In Sludges B and C, an additional 1 min was needed under conditions of 75 °C and 1355 W for a mass of 50 g. Moreover, Sludge A (46.27 × 105 or 4.80 ulog of dry matter), Sludge B (1.29 × 106 or 6.11 ulog of dry matter), and Sludge C (8.77 × 104 or 4.94 ulog of dry matter) were heavily contaminated with faecal coliforms. It took 6 min to reduce faecal coliforms to below the detection threshold.

A potential solution for clean water supply: multi-effect solar still and water quality analysis

Abstract Access to clean and safe drinking water is a significant challenge for individuals residing in suburban and remote regions of Pakistan. This study aimed to design, fabricate, and test a multi-effect solar still with four U-shaped condensing stages as a low-cost solution to this problem. The solar still was evaluated for its efficacy in removing common pollutants found in contaminated water sources. The results revealed an impressive 99% efficacy in eliminating various water pollutants, including conductivity, total hardness, pH, fluoride, and nitrate using the solar still. Water quality tests conducted for conductivity, total hardness, pH, fluoride, and nitrate revealed complete elimination of these parameters in most samples. Microbiological pollutants were also assessed through the presence/absence tests for fecal coliform and Escherichia coli, showing no presence in the distillate. In addition, the solar still effectively removed organic parameters, including alachlor, lindane, and endrin, within acceptable international standards. Thus, the proposed solar still has the potential to serve as an alternate method for producing safe drinking water in areas where access to clean potable water is limited. The findings of this study provide valuable insights for policymakers and researchers interested in addressing water scarcity in remote and suburban areas of Pakistan.

Assessing resilience of natural treatment system to variable contaminant loads in an urbanizing catchment

Constructed wetlands (CWs) offer solution to increasing wastewater concerns. Long term monitoring data (six years) provides information on robustness and life time of such systems. The CW system examined in this study was deployed to serve as a polishing stage for the sewage treatment plant (STP) effluent, however, it also receives raw sewage through stormwater drains. The hydraulic loading rate (HLR) of system increased from 215.5 ± 6.7 mm/day to 466.9 ± 21.6 mm/day in 6 years thereby reducing the hydraulic retention time (HRT) of the system. The effluent quality complied with the discharge standards except for ortho-P and fecal coliforms. Corresponding to HLR, the organic and nutrient loading rate also displayed significant variation during the period 2015 to 2020. Despite this, the organic load removal efficiency was comparable with only small variation. The nitrogen removal efficiency displayed significant fluctuation with occasional decline followed by improvement in the year 2020. The system released ortho-P into the water column increasing its load at the outlet, the ortho-P removal efficiency reduced from 19 to −44 % during the study period. Desilting, regular macrophyte harvesting, aeration and pre-treatment of raw sewage from open storm water drain can further enhance the system performance and robustness.

Antimicrobial resistance, virulence profile, and genetic analysis of ESBL-producing Escherichia coli isolated from Nile tilapia in fresh markets and supermarkets in Thailand.

This study investigated the prevalence and antimicrobial resistance (AMR) of Escherichia coli (E. coli) in Nile tilapia from fresh markets and supermarkets. A total of samples (n = 828) were collected from Nile tilapia including fish flesh (n = 276), liver and kidney (n = 276), and intestine (n = 276). Overall prevalence of fecal coliforms (61.6%) and E. coli (53.0%) were observed. High prevalence of E. coli was found in the intestine (71.4%), followed by the liver and kidney (45.7%). The highest prevalence of resistance was commonly found against tetracycline (78.5%), ampicillin (72.8%), and sulfamethoxazole (45.6%) with resistance to only tetracycline (15.2%) as the most common antibiogram. The prevalence of multidrug resistance (MDR) (54.4%) and Extended-spectrum beta-lactamases (ESBLs) (5.7%) were examined. The predominant virulence genes (n = 158) were st (14.6%), followed by eaeA (0.6%). The blaTEM (73.4%), tetA (65.2%), and qnrS (57.6%). There is statistical significance between Nile tilapia from fresh markets and supermarkets. Based on logistic regression analysis, ampicillin-resistant E. coli was statistically associated with the phenotypic resistance to tetracycline and trimethoprim, and the presence of blaTEM and tetA (p < 0.05). Further investigation of AMR transference and their mechanisms is needed for AMR control.

Effectiveness of wastewater treatment plant at the removal of nutrients, pathogenic bacteria, and antibiotic-resistant bacteria in wastewater from hospital source.

This study is aimed at assessing the effectiveness of hospital's wastewater treatment plant (WWTP) in removing nutrients, pathogenic bacteria, and addressing antibiotic resistance using a case study of a tertiary hospital in Ibadan, Nigeria. During the dry and wet seasons in the month of July and December, respectively, samples were collected, and analyzed using standard guidelines to examine significant physicochemical parameters of the WTTP; to evaluate the removal efficiency of biological oxygen demand (BOD) and chemical oxygen demand (COD), and to examine the prevalence of pathogenic and antibiotic-resistant bacteria. The results of this study showed that during the dry season, certain parameters exceeded acceptable limits, including temperature, total suspended solids (TSS), total dissolved solids (TDS), phosphate, and nitrate. Although there were reductions in BOD (1555mg/L to 482mg/L) and COD levels (3160mg/L to 972mg/L), they remained above acceptable limits by World Health Organization. In the wet season, the level of COD (20mg/L) in the effluent was within acceptable limit, while the BOD (160mg/L) was above the acceptable limit. The WWTP effectively removed nutrients and reduced the microbial load, as evident from the absence of fecal coliforms in the effluent in both seasons. In respect to BOD removal efficiency, the level of purification of wastewater by the WWTP was 69% during the dry season, while the removal efficiency of COD was 83.54% which showed the efficiency of the WWTP at the removal of COD. However, antibiotic resistance was still present. The study concludes that while the WWTP effectively addressed nutrients and microbial load, additional measures such as tertiary treatment methods like chlorination and UV radiation are necessary to tackle antibiotic resistance. This is crucial to prevent the release of antibiotic-resistant bacteria into the environment, safeguarding human health, animals, plants, and overall environmental well-being.

Leveraging aquatic-terrestrial interfaces to capture putative habitat generalists.

Habitat type is a strong determinant of microbial composition. Habitat interfaces, such as the boundary between aquatic and terrestrial systems, present unique combinations of abiotic factors for microorganisms to contend with. Aside from the spillover of certain harmful microorganisms from agricultural soils into water (e.g. fecal coliform bacteria), we know little about the extent of soil-water habitat switching across microbial taxa. In this study, we developed a proof-of-concept system to facilitate the capture of putatively generalist microorganisms that can colonize and persist in both soil and river water. We aimed to examine the phylogenetic breadth of putative habitat switchers and how this varies across different source environments. Microbial composition was primarily driven by recipient environment type, with the strongest phylogenetic signal seen at the order level for river water colonizers. We also identified more microorganisms colonizing river water when soil was collected from a habitat interface (i.e. soil at the side of an intermittently flooded river, compared to soil collected further from water sources), suggesting that environmental interfaces could be important reservoirs of microbial habitat generalists. Continued development of experimental systems that actively capture microorganisms that thrive in divergent habitats could serve as a powerful tool for identifying and assessing the ecological distribution of microbial generalists.