Sri Lankan Journal of Applied Sciences

Phosphorus Accumulation Rate (PAR) in Lake Sediments around Eppawala Phosphate Deposit (EPD): A Case Study for Prospecting New Phosphorus Sources

2023-08-07T18:29:51+0530

Currently, rock phosphate is predominantly used to produce phosphorus based mineral fertilizers for agricultural purposes. However, since rock phosphate is a finite and non-renewable resource, it leads the whole world vulnerable to a future phosphorus scarcity. Therefore, prospecting of new phosphorus sources is essential to address the phosphorus scarcity via a sustainable manner. In this regard, lake sediments around Eppawala phosphate deposit (EPD) in Sri Lanka is identified as a new area of interest. With respect to the location of EPD, there are two upstream lakes (Ihalahalmilla lake (L1) and Koon lake (L2)) and one downstream lake (Kiralogama lake (L3)) in the area which are fed by Jaya-Ganga. To access the potential of these lake sediments as a phosphorus source, core sediment samples were obtained and analyzed to determine average sedimentation rates (ASRs), mass accumulation rates (MARs) and phosphorus accumulation rates (PARs) based on P₂O₅%. The results reveal that L3 has the highest ASR (2.190 mm yr^-1), MAR (2935 g m^-2 yr^-1) and PAR (22.31 g m^-2 yr^-1) over the two upstream lakes. Therefore, it is evident that phosphate-bearing materials derived from the EPD have been continuously accumulated in the downstream lake sediment column with a high PAR. As a result, downstream lake sediments show the potential of being a secondary phosphorus source which can contributes to the phosphorus supply in local context. However, novel phosphorus extraction technique needs to be developed to get the maximum use of these lake sediments for a sustainable management of this secondary source.

Effects of functional groups in metal-organic frameworks of isoreticular UiO-66 topology in heavy metal removal: A Review

2024-01-23T22:35:38+0530

Wastewater treatment is a critical process for maintaining environmental sustainability and human health. Heavy metal pollution in wastewater poses a significant challenge due to its toxicity and persistence in the environment. Consequently, there is a growing endeavor to create efficient and reliable technologies for the elimination of heavy metals and, researchers have been driven to investigate emerging areas of material science due to their desire to create cost-effective, streamlined approaches. Metal-organic frameworks (MOFs) have emerged as promising materials for the removal of heavy metals from wastewater mainly due to high stability at aqueous medium, high surface area, tunable pore sizes, and exceptional adsorption capacities. Suitable synthesis or post-synthesis functionalization strategies can be employed to attain the desired characteristics in MOFs. Among the various MOFs, UiO-66 topology-based frameworks have demonstrated excellent performance in heavy metal removal, owing to their tailorable surface chemistry, selectivity, and regenerability. This review article aims to explore the effects of functional groups in heavy metal adsorption processes in MOFs of isoreticular UiO-66 topology in wastewater treatment. It provides an overview of the synthesis methods, structural properties, and surface modifications of UiO-66 MOFs. Furthermore, the article highlights the role of functional groups in enhancing the adsorption efficiency and selectivity of UiO-66 MOFs in heavy metal sorption and the stability of the MOFs in aqueous conditions.

Unlocking the Potential of Trichoderma: Exploring Its Role as a Beneficial Pesticide Agent and Unraveling the Intricacies of Signalling Pathways

2024-02-13T09:33:34+0530

In agricultural systems, insects are the primary pest, which results in considerable reductions in crop productivity and storage. Chemical insecticides are extremely hazardous to humans as well as to the environment and have been extensively used to manage insects during the past few decades. It is necessary to introduce an effective and eco-friendly alternative to minimize the usage of chemical insecticides. Trichoderma species are widely studied and used as a biocontrol agent in agriculture systems
due to their direct and indirect mechanisms involved in pest control. Direct and indirect pest management is mainly associated with mycoparasitism and activation of systemic plant defensive responses respectively. As mycoparasitic interactions are not merely a contact response, it is evident that Trichoderma recognizes signals from the host fungus and triggers the transcription of genes relevant to the biocontrol processes. Recent studies on the signalling pathways underlying Trichoderma biocontrol have revealed that heterotrimeric G-proteins, mitogen-activated protein (MAP) kinases and cAMP pathways have a crucial impact on processes that are involved in biocontrol. This review summarises the effect and the signalling pathways of Trichoderma as a biocontrol agent against pests.

Influence of Land Use on the Water Quality of the Upper Mahaweli River: A Comparative Analysis in Dry and Wet Weather Conditions

2024-01-23T22:33:47+0530

Understanding the relationship between land use and surface water quality is paramount for effective water management. A limited amount of research has been carried out focusing the effect of land use pattern and water quality of river basins in Sri Lanka, thus a study focused on the longest among all has not been traced in the literature up to data. As such this study has been carried out to investigate the, variations in water quality of Mahaweli River in relation to the different land use pattern. Water quality of the selected river stretch was examined for duration of four months and those were correlated with the land use data of watershed area of the river and the rainfall data of pertinent catchment. Study area was divided into three catchments based on their land uses. 15 water quality parameters at 10 sampling locations of study stretch were recorded. Analysis of land use data in three catchments revealed that there was a significant increment of urbanization from upper end to the lower end of the study area whereas agricultural and forest areas were prominent in the upper most catchments. Moreover, analysis portrayed that there was a significant impact from land use patterns on water quality. Ammonia-N, Turbidity, COD and BOD5 have observed to be dominant in urbanized catchments. Higher level of TSS has been observed with the increment of the agricultural/forest ratio. BOD5, EC, COD, Fecal coliform and TOC have been escalated with the increment of urban/forest ratio. Interestingly, most of the water quality parameters are not affected by the rainfall fluctuations in selected three catchments. Although the water quality parameters show significant variations with the impact of land use patterns, overall water quality classified as Water Quality Index (WQI) was similar for all three catchments.

Development of a Batter Using Cassava, Chickpea and Soy Starch for Deep-Fried Chicken

2024-02-13T09:36:08+0530

This study examined the effects of different flour-batter compositions (wheat, chickpea, cassava, and soy) on deep-fried chicken, evaluating both overall satisfaction and sensory preferences. The batter made with cassava flour was the most popular option, while the batter made with soy flour was the least popular. After several sensory evaluations with 100 panelists, it was discovered that the blend of 35.9% cassava flour and wheat flour had the highest level of general approval. Accepted batter and deep-fried chicken qualitatively analyzed over the time and it recorded that, the pH, water-holding capacity, and microbial count of this ideal composition decreased. The final batter's approximate analysis included 5.09g of moisture, 2.53g of proteins, 12.3g of fat, 1.86g of fiber, and 1.13g of ash. Important information about flour selection for deep-fried goods is provided by the study, which emphasizes water-holding capacity, pH variations, batter composition, sensory qualities, and microbiological dynamics. These results provide insightful direction for new culinary art, product development, guaranteeing.