Mahendra Aryal

• Ph.D.
• PostDoc at Aristotle University of Thessaloniki

Water quality monitoring is a fundamental component of sustainable management of water resources. This review outlines the progression of water quality assessment, transitioning from traditional methodologies to advanced technologies such as remote sensing, nanotechnology, sensor networks, and artificial intelligence. It emphasizes the transformati...

In natural environments, persistent pollutants such as heavy metals and organic compounds, are frequently sequestered in sediments, soils, and mineral deposits, rendering them biologically unavailable. This study examines phytoremediation, a sustainable technology that uses plants to remove pollutants from soil, water, and air. It discusses enhanci...

This study is a comprehensive assessment of the waste management system in Besisahar municipality. Information and some data have been collected from the municipality of Besisahar, followed by interviews with municipal officials responsible for waste management, stakeholders, waste workers, and residents. A total of 230 households, 20 schools, 10 g...

Nepal has a high annual rainfall, but it still faces numerous challenges in ensuring good water quality. A total of 20 water samples were collected from five springs, seven rivers, one borehole, and seven reservoir tanks. pH, electrical conductivity, total dissolved solids, turbidity, total hardness as CaCO 3 , and residual chlorine in the water sa...

Enteric fever is one of Nepal's most serious public health problems. An investigation was conducted to determine the prevalence of Salmonella species in enteric fever patients and the patterns of antibiotic susceptibility. In a study of 675 cases, only 22 Salmonella species were isolated. There was a low positivity rate of 3.25 % among the isolates...

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants that are considered toxic, carcinogens, and mutagens. One of the major concerns of environmental problems is the presence of PAHs due to the various natural and anthropogenic activities. The presence of PAHs in the environment creates problems since their presence has...

The main aim of this study was to maximize tartaric acid recovery, and to optimize total phenolics, sugars, and antioxidant activity present in industrial red and white tartar wastes. Total tartaric acid contents were determined at 4.87 and 3.98 g/100g-dry mass of red and white tartar wastes using ion chromatography. Based on chemical precipitation...

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous micro-organic pollutants that originate primarily from natural and anthropogenic activities. Water pollution due to such micro-organic contaminants is a serious problem because of their acutely toxic, carcinogenic, and mutagenic nature. Therefore, a sustainable remediation technique is essentia...

Discharges of waste containing heavy metals (HMs) have been a challenging problem for years because of their adverse effects in the environment. This article provides a comprehensive review of recent findings on bacterial biosorption and their performances for sequestration of HMs. It highlights the significance of HM removal and presents a brief o...

This study assessed the process of managing the health care wastes and their disposal in one of the major hospital in Lamjung district, Nepal. It was found that the hospital does not quantify solid wastes and segregation of the different types of wastes is not so well practiced. Average awareness of the magnitude of hospital waste management of hos...

A novel biosorbent, Eupatorium adenophorum Sprengel-alginate beads was used for chromium(VI) biosorption from aqueous solutions. Biosorption process was optimized at pH 2.0, biomass concentration 1.0 g/L, contact time 60 min, and temperature 30 oC respectively. Maximum uptake capacity of Cr(VI) was calculated at 28.011 mg/g. It was found that the o...

A novel biosorbent, Eupatorium adenophorum Sprengel was used for biosorption of chromium (VI) from aqueous solutions. Optimum pH, biomass concentration and contact time were estimated at 2.0, 1.0 g/L and 60 min respectively. Data obtained from batch studies confirmed well to the Langmuir model. It was found that the overall biosorption process was...

Heavy metals are among the most common pollutants found in the environment. Health problems due to the heavy metal pollution become a major concern throughout the world, and therefore, various treatment technologies such as reverse osmosis, ion exchange, solvent extraction, chemical precipitation, and adsorption are adopted to reduce or eliminate t...

This paper discusses the biosorption of Ni(II) ions from aqueous solutions by Bacillus sphaericus biomass. The biosorption process was affected by the solution pH, biomass concentration, contact time, temperature and initial Ni(II) concentration respectively. The sorption kinetics and equilibrium data were described well with the pseudo-second orde...

Evaluation of wine wastes for isolation of added value products with applications in food and pharmaceutical industries, cosmetology etc was carried out. Samples of different wine wastes from red and white vinification were examined for their content in tartaric acid as well as in total phenolics and sugars. Based on chemical precipitation and sepa...

Batch experiments were performed for different initial phenol concentrations in the presence of glucose to observe cell growth and associated phenol degradation using Pseudomonas sp. cells. It was observed that phenol degradation increases with increasing the tolerance of the cells to phenol inhibition using glucose in the growth medium. The maximu...

Grapes are among the largest fruit crop in the world, of which ~80% is used for wine making. The recovery of natural antioxidants from wine industry by-products is of great importance, not only because of their aforementioned significant properties, but also because it could exploit a large amount of the wine industry wastes, which are mainly used...

BACKGROUND Mycobacterium sp. biomass was used for removal of Cr(III) and Cr(VI) species from aqueous systems. Experimental results were processed with different kinetic, isotherm and thermodynamic models. Studies of the effect of co-ions, biomass characterization and desorption were also undertaken. RESULTSCr(III) and Cr(VI) sorption on Mycobacteri...

Surfactant-enhanced solubilization and subsequent biodegradation of phenanthrene and pyrene from aqueous solutions by Arthrobacter strain Sphe3 was investigated. The results show that growth of Arthrobacter strain Sphe3 was increased upon increase in concentration of Tween 20 and Tween 80. Inhibition of bacterial growth was observed with increasing...

Pseudomonas sp. biomass was used to remove Fe(III) ions from aqueous solutions. Optimum values including pH, biomass concentration and biomass-Fe(III) contact time were determined at 2.5, 1.0 g/L, and 25 min respectively. The maximum uptake capacity of Pseudomonas sp. biomass for Fe(III) was calculated at 86.206 mg/g using Lang-muir isotherm model....

Arthrobacter sp. Sphe3 and Bacillus sphaericus cells were used for Cu(II) biosorption. The effect of contact time, biosorbent dose, equilibrium pH, temperature and the presence of other ions on the efficiency of the process were extensively studied. Optimum pH value and biomass concentration were determined at 5.0 and 1.0 g/l, whereas contact time...

The non-metals as well as heavy metals and polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment. The common sources of inorganic and organic toxic substances are from industrial, agricultural, household, municipal and medical wastes. Remediation of these toxic substances from the contaminated sites is very important, since they...

The biosorption of phosphate from aqueous solutions using Fe(III)-treated Staphylococus xylosus cells was investigated. Langmuir and Freundlich isotherm models were applied to describe the adsorption equilibrium and found that Langmuir isotherm model fitted the equilibrium data better than Freundlich isotherm model. The biosorption capacity of Fe(I...

Chromium(VI) and arsenic(V) biosorption in single and binary mixtures using Fe(III)-treated Staphylococcus xylosus were investigated and compared. In single biosorption experiments, the maximum uptake capacity of both Cr(VI) and As(V) was observed at pH 3.0 and biomass dosage 2.0g/L. Langmuir isotherm model described the adsorption equilibrium for...

As(III) and As(V) biosorption using Staphylococus xylosus biomass pretreated with Fe(III) solutions were investigated here. Biomass at initial concentration of 7.0 g·l−1 was treated with 900 mg·l−1 of Fe(III) at pH 3.0, and contact time 1.0 h. Optimum values including pH, biomass concentration and biomass-arsenic contact time, were first investigat...