No abstract

This study was conducted to assess water quality variations and identify potential pollution sources in two lakes namely Begnas and Rupa, Lesser Himalayas Pokhara, Nepal during monsoon season in June 2016. A total of 18 water samples (n= 9, from each lake) were collected and major physicochemical parameters were analyzed: pH, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), biological oxygen demand (BOD), nitrate-nitrogen (NO3-N), phosphate- phosphorus (PO4-P), ammonia, chloride, free CO2 and total hardness (TH).The results revealed that the water of both lakes were relatively pure with very less TDS as compared to other lakes considered for the comparison with this study. However, the concentrations of CO2 and phosphates were found to be higher than WHO guidelines for drinking water and also indicated the problem of rapid eutrophication in both of the lakes. Thus, the higher concentrations of organic pollutants and the rapid eutrophication process could be the serious threats that should be considered by the concerned authorities for the sustainability of the lakes in future.

Kathmandu, the capital city of Nepal is one of the most populated destinations of the country. The water pollution remains a challenging issue for the sustainable development in the valley despite several pollution control devices, awareness-raising and policy measures. During monsoon period 2018, surface water samples were collected from 10 sites of the Bagmati River and its tributaries within the valley to evaluate the water quality. The different physico-chemical parameters were determined to assess pollution along a 26.5 km stretch between Sundarijal Dam to Balkhu Bridge of the Bagmati River and its selected tributaries. The Electrical Conductivity (EC) ranged from 33-816μS/cm while turbidity ranged from 0.3- 981 NTU and Total Dissolved Solids (TDS) ranged from 16 to 612 mg/l. The ionic concentrations were higher in the lower sections where the population density is high compared to the head waters. The high value of TDS and low value of Dissolved Oxygen (DO) in the lower belts of rivers were due to large inputs of waste water, uncoordinated rapid urban expansion, inadequate waste water treatment facilities and organic loads caused by anthropogenic activities. A comparative study for the water quality variables in the urban areas showed that the main river and its tributaries were equally polluted. From water analysis, downstream sites showed contamination and comparatively polluted among the tributaries and Bagmati River. There is a need to take action plan against polluted site for sustainability of aquatic health of the riverine environment and to address the river for its longer life both by public and government sectors.

Traditional herbal medicines have been consumed in Nepal and other parts of the eastern hemisphere since ancient times. Many of these plants reportedly have been effective against ailments as well. This study aims to analyze the phytochemical constituents from the extracts of ten such plants and evaluate their antimicrobial, cytotoxicity, and antioxidant properties. In addition, the study aims to study the correlation of cytotoxicity and antioxidant activities with the total phenolic, flavonoid, and tannin contents. The plants investigated were Oroxylum indicum, Kalanchoe pinnata, Phragmites vallatoria, Ehretia acuminata, Cirsium wallichii, Ampelocissus tomentosa, Dichrocephala integrifolia, Boenninghausenia albiflora, Cynoglossum zeylanicum, and Clerodendrum serratum. Phytochemical analyses were performed to evaluate secondary metabolites, such as glycosides, flavonoids, terpenoids, saponins, alkaloids, and fats. The total phenolic contents of the extracts ranged from 14.94 to 229.89 mg GAE/g, the total flavonoid contents varied from 66.67 to 900 mg QE/g, and the total tannin contents were 42 to 168 mg GAE/g. The results of the antioxidant studies showed that the highest antioxidant activity was exhibited by the extract of A. tomentosa (IC50 = 7.89 µg/mL) followed by E. acuminata (IC50 = 24.82 µg/mL) and C. serratum (IC50 = 32.91 µg/mL). The extracts from P. vallatoria and A. tomentosa exhibited substantial antimicrobial activity. The extracts of A. tomentosa and B. albiflora showed lethality against brine shrimp with LC50 values of 33.11 µg/mL.

No abstract