JOURNAL OF APPLIED RESEARCH IN WATER AND WASTEWATER
Year:2023 | Volume:10 | Issue:2|Papers Count:12

Low-energy extraction wells fitted with filtration sleeves were numerically modeled to assess their capability to extract narrow contaminant plumes in a hypothetical unconfined aquifer beneath a lined landfill. After 2,000 days, the source was shut off and remediation simulations commenced. A sleeved submersible pump extracting 0.4 m3/day in a well near the downgradient edge of the plume, coupled with an upgradient well injecting the same rate, effectively contained and removed the plume. Adding non-pumped filtration wells upgradient of the extraction well marginally improved containment and remediation timeframe. At some sites, low-energy, sleeved extraction wells may be useful for extracting narrow plumes emerging from contemporary landfills.

Access to safe water and sanitation is a basic human right and is enshrined in the sustainable development goal 6. Consequently, resources have been channeled towards development and improvement of water sources. Unlike surface water, the demand for groundwater is increasing due to its preserved quality, affordable development capital and drought resilience. Population density has resulted into entry of pollutants into aquifers because of reduced distance between the pollutants and groundwater sources, human activities and hydrogeological conditions. The aim of this study was to carry out an assessment of groundwater vulnerability to contamination as a preventive approach. Webuye town is a service area of Nzoia Water Services which provides water and sewerage services. However, water and sanitation coverage in Webuye town still below 50%, a portion of residents rely on onsite sanitation systems and groundwater. This is due to costs of installation, topographical challenges and limited pipeline extensions. It was observed that areas where groundwater sources are predominantly used, human waste is managed onsite close to groundwater abstractions points. The methods used in this study included the application of DRASTIC model which was interfaced in ArcGIS version 10.3. Inverse distance weighted (IDW) interpolation technique was used to produce vulnerability maps. The model inputs were seven: depth, recharge, aquifer, soil properties, topography, impact of the vadose zone, hydraulic conductivity and Land use. The results show that North Eastern areas of the study area; Maraka (Township) and Muchi scored the highest DRASTIC-LU values, implying high chances of groundwater vulnerability to contamination. The shallow water table, groundwater recharge, the type of soil, slope and the land use activities in the study area resulted into increased vulnerability. The findings should inform the municipality management on water quality precautions to be undertaken while developing groundwater sources in the area and development of pollution control framework.

A total of 114 samples collected from hospital wastewaters and rivers in Addis Ababa, Ethiopia were tested for non-sorbitol fermenting bacteria and coliphages. Sorbitol MacConkey agar is mainly used in the detection of E. coli O157:H7. However, other emerging diarrhoeagenic enteropathogens such as Plesiomonas shigelloides, Edwardsiella tarda, Providencia alcalifaciens, Escherichia albertii, Escherichia vulneris and Escherichia fergusonii were detected in the samples using this medium. Information for most of the emerging enteropathogens is scarce in most countries including Ethiopia. A total of 20 different genera, 38 species of non-sorbitol fermenting bacteria were isolated. Escherichia coli O157 could not be detected from any of the samples. All these backgrounds may mask the detection of Escherichia coli O157. Even if sorbitol MacConkey agar has several background limitations, different emerging diarrhoeagenic non-sorbitol fermenting bacteria were detected in the majority of the rivers and hospitals` wastewaters samples. The correlation between coliphages and non-sorbitol fermenting bacteria were not significant. As several bacteria have been isolated on sorbitol MacConkey agar medium, it is essential that the most selective laboratory techniques will be desired for outbreak investigation of E. coli O157, but other non-sorbitol fermenting enteropathogens should also be detected using sorbitol MacConkey agar in low resources countries.

This research devised a cutting-edge artificial intelligence methodology to enhance flood forecasting in Quebec, Canada, an area frequently affected by floods. The core of this project was creating a novel artificial intelligence (AI) model (i.e., Generalized Structure of Group Method of Data Handling) dedicated to the early detection of potential flood events. Utilizing data from two key hydrometric stations, Saint-Charles and Huron, located within the region, the study aggregated data from 15-minute intervals into comprehensive hourly averages. An initial analysis sought to understand the relationship between river flow rates and the environmental factors of temperature and precipitation upstream and downstream. The investigation uncovered intricate relationships among these factors, presenting challenges in accurately predicting floods. To address this, a specialized AI model was developed to translate the flow data from the Huron station to predict potential flooding at the Saint-Charles station. This model, leveraging 48-hour lag data from upstream, was designed to forecast flood events at the Saint-Charles station with lead times ranging from one to eighteen hours. The model demonstrated significant predictive accuracy, with a correlation coefficient surpassing 0.9. Consequently, this innovative AI model emerges as a promising tool for improving Quebec's flood prediction and early-warning systems.

Hg and Pb metals are major concerns because of their high degree of toxicity in public environment, which also pollute aquatic systems. Nanocomposite adsorbents have been developed for cleaning polluted water at low. The study aims to determine the removal efficiency of magnetite carbon dots nanocomposite in case of Hg and Pb in the aqueous solution. In this paper, magnetite carbon dots (symbolized as Fe3O4/CDs) nanocomposite was synthesized through a two-step process of co-precipitation and pyrolysis methods. The synthesized nanocomposite was analyzed using Utraviolet visible (UV-vis), Fourier transform infrared spectroscopy (FTIR), scanning electron electron microscopy (SEM), electron dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD) and atomic absorption spectrophotometer (AAS). According to the results, the synthesized (Fe3O4/CDs) nanocomposites were found to be 20 nm in diameter, superparamagnetic property, surface roughness and deformations, important functional groups, iron-rich nanocomposite and favorable removal efficiency for Hg (82.70 %) and Pb (72.91 %), respectively. Therefore, the results indicated that these Fe3O4/CDs nanocomposites are potentially attractive agents for the removal of heavy metals ions, especially Hg and Pb from industrial wastewater.

The discharge of industrial waste containing organic pollutants like phenol has caused a surge in environmental complications in water, soil, and air. In recent years, the concentration of phenolic pollutants has risen due to their high toxicity and environmental persistence. This research used geotextile/activated carbon (GTX/AC) adsorbent to purify groundwater contaminated with phenol, owing to its easy availability. A low-cost geotextile carrier was utilized to avoid the dispersion of active carbon in the groundwater. Response surface method (RSM) was used in the present research to design and optimize experimental tests. The results indicate that the initial concentration, pH, and adsorbent dosage are the most significant parameters affecting the geotextile/activated carbon (GTX/AC) adsorbent performance. Maximum adsorption capacity was considered the highest desirability level for the response surface method optimization. The initial phenol concentration equal to 458.8 mg/L, the amount of pH equal to 7, and the dose of adsorbent equal to 5.5 gr were the best conditions for removing phenol from the water. Based on the result of this research, the response surface method can be used for modeling and optimizing phenol adsorption from groundwater, and geotextile/activated carbon (GTX/AC) adsorbent is a suitable choice for the treatment of water polluted with phenol.

The importance of water shortage in arid and semi-arid regions is more evident due to the limitation of water resources, and the preparation of water resources is necessary to protect and reduce the vulnerability of these resources. Therefore, in this study, considering the vulnerability of water and soil resources in arid and semi-arid regions and the geographical structure of Zagros inland basins, the Izadkhast plain from the south of Fars province was selected to investigate the vulnerability of water resources. For this purpose, six parameters of water depth, net feed, aquifer environment, soil texture, topography, and hydraulic conductivity of the aquifer were analyzed using the DRASTIC model. The results showed that almost 50% of the plains were in the high vulnerability class, and 28% were in the very high vulnerability class. In the east and center of the plain, places with high vulnerability to pollutants and contaminated water were found. The effect of the formations in the east of the basin can be seen because, at the outlet of the rivers in the east of the basin, the amount of sulfate has increased dramatically, which indicates the presence of evaporate formations with gypsum. In the center of the basin, the heavy texture of the soil, the low slope, and the accumulation of most of the water entering the basin, some of which have a lot of salts, have increased the vulnerability of this part. Another result of this study is that the DRASTIC model has high efficiency in evaluating vulnerabilities similar to this research.

Wetlands, as temporary or permanent water reservoirs, provide various benefits for the ecosystem, such as water supply, waste water treatment, and dust control. By the end of 2023, the Iranian government and the Ramsar Convention have registered 25 international and 226 national wetlands. West Azerbaijan and Mazandaran provinces have more wetland ecosystems than any other provinces. Semnan, Yazd, and Zanjan provinces have no wetlands. According to the Ramsar Convention of 1971, Iran has 32 aquatic ecosystems that have the potential to become wetland. In addition, according to the available data and the WHO standard, eight wetlands have the highest probability of producing dust and should be given more attention and care. We recommend the wetland management plan, which ensures their water requirements, protects them from degradation and pollution, and promotes their ecological restoration. Satellite image analysis can help explore how climate change affects dust intensity, considering the role of wetlands in dust control.

Fumarate-alumoxane nanoparticles (Fum-ANPs) incorporated PES nanofiltration membrane was fabricated via phase inversion to achieve favorable performance as the enhancement in the dye removal and antifouling capacity. FTIR spectra of the Fum-ANPs revealed that the carboxylate and hydroxyl functional groups were created on the surface of Fum-ANPs. The strong affinity of Fum-ANPs functional groups with water molecules made the membrane surface more hydrophilic. Hence, the modified membrane sample had a higher pure water flux than the bare one. Zeta potential data showed that the Fum-ANPs blended PES membrane was negatively charged at a pH value of 6, which is favorable for negatively charged solute rejection. The antifouling behavior of the membranes was analyzed using powder milk solution (8 g/L) in a dead-end filtration system. The obtained results demonstrated that the introduction of Fum-ANPs in the membrane matrix ameliorated the antifouling behavior of the resulting membrane. To further study the performance of the Fum-ANPs incorporated PES membrane, removal of Direct red 16 dye was tested. The removal efficiency of Direct red 16 with the Fum-ANPs blended PES membrane was 99% while it was 88.2% for the bare membrane sample.

This study explored the efficacy of a cost-efficient activated carbon (AC) derived from natural bitumen through chemical activation with phosphoric acid. The objective was to evaluate bitumen-based activated carbon (AC) potential as a novel adsorbent by integrating Cu (NO3)2.3H2O onto AC for the removal of harmful dyes from water-based solutions. Assessments of the adsorption capabilities of Cu@AC were conducted using representative samples of cationic and anionic dyes, namely methylene blue (MB) and methyl orange (MO). The incorporation of Cu onto the AC, leading to the formation of Cu@AC, resulted in a significant enhancement of the adsorption capacity of AC. The adsorption capacity of Cu@AC was measured using Brunauer–Emmett–Teller (BET) and iodine number measurements, with the most optimal Cu@AC sample exhibiting a BET surface area of 611 m2/g. Surface chemical properties were analyzed through FT-IR spectroscopy, while the microstructure of the produced Cu@AC was examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The efficiency of the adsorption process was influenced by factors such as pH, initial dye concentration, adsorbent dosage, and contact time. The most effective processing conditions for dye removal were determined as pH 11 for MB and pH 5 for MO, with an initial concentration of 25 mg/L, a 0.5 g/L adsorbent dosage, and a temperature of 333 K for a duration of 90 min. Under these optimized conditions, removal efficiencies exceeded 90% for MO and 80% for MB. The results demonstrated that Cu@AC has the potential to function as a cost-effective alternative to commercially available activated carbons for efficiently eliminating dyes from contaminated water.

Inexpensive and new adsorbents, which are produced by processing the abundant agricultural by-products, can provide an efficient solution for a cleaner environment. The occurrence of heavy metals in water may pose a significant threat to human health. In this work, the processed date kernels are used to remove chromium (VI) and iron (III) from water. The XRD, FTIR, SEM, VSM and EDX techniques are used to characterize the adsorbents. The equilibrium adsorbent dose for iron is 2 g/L while for chromium (VI) it is 4 g/L and the equilibrium time is 20 min. Moreover, acidic conditions favored the adsorption for both targets. The adsorption experiments showed that the kinetics of adsorption of chromium (VI) and iron (III) on date kernel powder fitted the pseudo-second-order model. The optimum adsorption capacities for iron (III) and chromium (VI) are 10.5 mg/g and 0.66 mg/g, respectively. In the meantime, the remarkable efficiency of the date kernel-based adsorbent for iron (III) removal paves the way for designing new magnetic adsorbents.

Agricultural product processing generates substantial quantities of agricultural waste and their disposal has become a critical concern, threatening human health and the environment. The pyrolysis process is an upgrading technology for producing valuable products from waste feedstocks. Hence, the potential of eco-friendly biochar derived from cotton waste was comprehensively investigated for methylene blue removal. The cotton-based biochar contained various pore sizes and functional groups on the surface verified by SEM and FTIR analyses. The impacts of adsorbent dose, methylene blue concentration, temperature, pH, and contact time on the adsorption of methylene blue were assessed to highlight the efficiency of the cotton-based biochar. The results revealed >90% removal under 10 mg/l methylene blue concentration, 0.7 g adsorbent dose, pH of 6, and contact time of 60 min at a temperature of 20 ⁰C. The adsorption isotherm was well-fitted with the Freundlich model, indicating the multilayer methylene blue adsorption. The adsorption process was chemisorption and endothermic based on kinetic and thermodynamic modeling. Summing up, it can be suggested that the cotton-based biochar can be easily and efficiently applied for methylene blue removal from aqueous solutions, and further investigations are required to modify its specific surface area by a green synthesis approach.