Consequential study on different levels of C/N ratios used in biofloc-based aquaculture system

Biofloc technology is much highlighted these days because of its tremendous effects on aquaculture. Microbes were enriched on cheapest organic carbon source i. e., powdered banana peels and were incorporated in different aquaria rearing grass carp fingerlings under different C/N treatments (10:1, 15:1 and 20:1) and 10% water daily water exchange. The initial growth of fingerlings was recorded. The experiment was settled in triplicates for 60 days and run parallel to control group provided with commercial feed and daily water exchange. Its effect was evaluated by measuring the growth of fingerlings and water parameters of each aquarium. The average % gain in weight and length of fingerlings was obtained significantly highest (28.12 ± 0.30g and 17.29 ± 0.46cm respectively) in aquaria containing pure powdered banana peels with 10% water exchange and C/N ratio was adjusted at 20: 1 (T3) than other treatments and control. Ammonia and other water parameters were also under control in T3 than other experimental and control groups. By all counts, it was concluded that the highest C/N ratio in biofloc system had the potential to increment C. idella growth rate by reducing toxicity and could be used as fish meal substitute.

Experimental study on the analysis of nanocellulose treated water in Yola metropolis, Nigeria

In this study, cellulose from sugarcane bagasse and wood pulp were converted to nanocellulose and utilized to treat water from different sources within Yola Metropolis to study the efficacy of both methods. From the analysed water parameters, both nanocellulose materials were effective in treating contaminated water. They showed the capability of reducing the concentrations of the various tested parameters such as Total Dissolved Solids (TDS), Nitrate, Chloride, and Nephelometric Turbidity Units (NTU). Interestingly, analysis of the heavy metal concentrations before and after water treatment with the nanocellulose, showed very significant reduction of the heavy metals. This is encouraging as we explore more efficient methods of water treatment, in order to tackle rising cases of lead and other heavy metal poisoning in Nigeria due to illegal mining activities and deregulated industrial activities. Dans cette recherche, la cellulose de la bagasse de canne à sucre et de la pulpe de bois a été converties en nanocellulose et utilisées pour l’épuration d’eau de différentes sources au sein de Yola Metropolis afin d’étudier l’efficacité des deux méthodes. D’après les paramètres d’eau analysés avec les deux types de nanocelluloses étaient efficaces dans le traitement de l’eau contaminée. Ils ont considérablement réduit les concentrations des différents contaminants testés tels que le TDS, le nitrate, le chlorure et le NTU. En effet, l’analyse de la concentration en métaux lourds avant et après le traitement de l’eau avec la nanocellulose a montré une réduction très significative des métaux lourds. C’est une bonne chose car nous explorons des méthodes plus efficaces de traitement de l’eau, pour lutter contre l’augmentation des cas d’empoisonnement au plomb et à d’autres métaux lourds au Nigeria en raison d’activités minières illégales et d’activités industrielles non réglementées.

Проявление линии Видома при микроволновых измерениях увлажненных перекисью водорода сорбентов

For deeply supercooled bulk water, anomalies of thermodynamic values are known near the Widom line, the locus of increased fluctuations of entropy and density. In this work, we measured the reflected power of microwave radiation at a frequency of 18 GHz from a silicate sorbent sample moistened with a hydrogen peroxide solution. In the experiment, we observed variations in the recorded reflected radiation power in the range –46 – –47 °С, determined by structural changes in the liquid. Thus, it is shown that fluctuations of water parameters near the Widom line are manifested in changes not only in thermodynamic, but also in electrophysical quantities.

Dinaric karst intermittent rivers harbour some rare mayflies (Insecta, Ephemeroptera)

While investigating the aquatic macroinvertebrate fauna of four intermittent Dinaric karst rivers in Croatia, we confirmed or recorded new distribution data and ecological features for several mayfly species rare in Croatian freshwater habitats: Nigrobaetis niger (Linnaeus, 1761), Procloeon pennulatum (Eaton, 1870) and Paraleptophlebia werneri Ulmer, 1920. To our knowledge, this is the first record of N. niger in intermittent lotic habitats. We discuss their substrate preferences in the studied habitats as well as their relationships with measured physico-chemical water parameters. The newly obtained results confirm that our knowledge about Croatian mayfly fauna and species ecological requirements in intermittent Mediterranean rivers is still incomplete and is increasing with systematic studies.

Sustainable Development Indicators—Untapped Tools for Sustainability and STEM Education: An Analysis of a Popular Czech Educational Website

Environmental education has been included in Czech curricula since the 1980s, albeit without clear evidence of education for sustainable development (SD), which addresses complex socio-economic issues using SD indicators (SDIs), such as charts, single numbers, tables, maps, and (interactive) images. However, understanding such a comprehensive topic requires developing basic mathematical knowledge and skills. In this study, we aimed to analyse the nature, quality, and availability of teaching materials for SD, primarily using SDIs, which could be applied by Czech teachers. For this purpose, we performed a qualitative and basic quantitative content analysis of several descriptors of documents retrieved from a website for teachers, provided by the National Pedagogical Institute of the Czech Republic. A full-text search identified 1376 records, which were analyzed for SD pillars and SDIs. Our results showed that most records (95%) do not contain SDIs in teaching materials. Only 59 records mentioned (128) SDIs, mostly covering the environmental pillar, 26 of which contain a single SDI. The most frequent issues were waste production, treatment, savings, water parameters, and energy consumption. Mathematical skills were used in 56 SDIs, primarily for evaluating data sets and quantitative expressions of an amount. Overall, only a small number of SDIs are used in education for SD, economic and social SDIs are in the minority, and the STEM potential remains untapped.

A Study of Dispersed, Thermally Activated Limestone from Ukraine for the Safe Liming of Water Using ANN Models

Liming surface water is a fairly popular method of increasing the pH values and decreasing the concentration of phosphates and heavy metals. According to the Environmental Protection Agency (EPA) recommendations, the increase of water pH should not exceed 1.5. If surface water is the source of water supply, liming is a process that reduces water contamination. This should prevent the creation of an additional load for the water treatment plants in urban settlements. This article is an interdisciplinary research study aiming to (1) determine and compare the doses of new dispersed, thermally activated limestone and natural limestone, (2) find the relation between dose value and initial water parameters (pH, Eh and total mineralization), and (3) create an artificial neural network (ANN) model to predict changes in water pH values according to EPA recommendations. Recommended doses were obtained from experimental studies, and those of dispersed, thermally activated limestone were lower than the doses of natural limestone. Neural networks were used to predict the changes in water pH values when adding different doses of limestone with different initial water parameters using the ANN model. Four ANN models with different activation functions and loss function optimizers were tested. The best results were obtained for the network with the ReLU activation function for hidden layers of neurons and Adam’s loss function optimizer (MAPE = 14.1%; R2 = 0.847). Further comparison of the results of the loss function and the results of calculating the quality metric for the training and validation dataset has shown that the created ANN can be used to solve the set research issue.

Hydrological and Environmental Study on Surface Water Characterization in a Locality in North Eastern India

Rapid industrialization, road cutting, excavation and indiscriminate use of chemical fertilizers and pesticides in agriculture practices are causing varied pollution in aquatic environment, leading to deterioration of water quality and depletion of aquatic biota. Due to use of this contaminated water, human population suffers from various water borne diseases. It is therefore necessary to check water quality at a regular interval of time to determine whether it is good for consumption or other purpose such as irrigation, industrialization etc. In this study paper, hydrological and environmental characterization of surface water was done by different water quality parameters conducted in water samples at Kamle District of Arunachal Pradesh, India, reported for both pre- and post-monsoon periods. The physical and chemical water parameters such as pH, temperature, dissolved oxygen, turbidity, total dissolved solids, nitrate, and phosphate were analyzed and are studied. Water quality index was then determined by using National Sanitation Foundation (NSF) method. Based on these data, the surface water from different sources is classified as unacceptable, poor, medium, good and excellent.

Saving the endangered Native Victoria Tilapia, Oreochromis variabilis Boulenger (1906), in Upper Victoria Nile

This study investigated the catch estimates, mortality, growth, food and feeding habits, and water parameters of Oreochromis variabilis in Upper Victoria Nile (UVN) from 2008 to 2019. Catch rates ranged 0.32±0.08 to 3.42±1.13 kg, boat-1, day-1 with the length-weight relationship indicating Isometric growth. Growth parameters obtained were L∞=36.75, K=0.44 yr-1, t0=-0.4540, tmax=6.4years, ØL=2.774, ØW=-0.301. Total mortality (Z) was 1.74yr-1, natural mortality (M) =0.95yr-1 using riverine surface temperature (RST) of 26oC giving a fishing mortality F of 0.79 yr-1 and exploitation ratio (E) of 0.4504 showing that growth parameters concurs with annual estimates and yield (F=6.589; P±=0.05). Catch estimates correlated with water parameters that indicated a significant difference. Mortality parameters showed that the fishery could be experiencing exploitation pressure. Although growth rates revealed that the fish is a long-lived species, if managed properly, its population could recover. Therefore, culturing the species and restocking in rivers and lakes in which this specie was not observed in the East African region are recommended.

EVALUATION OF DELONIX REGIA SEEDS AS A NATURAL COAGULANT IN THE TREATMENT OF LOW TURBID WATER

This research aims at evaluating the effectiveness of Delonix regia as a natural coagulant in treating low turbid water. The active ingredient of the coagulant was extracted using Soxhlet Apparatus with Hexane as the solvent. The water sample was obtained from the famous Ala river in Akure, Ondo state. The water from this river is oftentimes used by the residents without treatment because it appears clean to them, this river had a turbidity of 18.4NTU which is above the standard (5NTU) required by the World Health Organization (WHO) for safe usage. After treating with different doses (0.03g/L to 0.4g/L) of the coagulant, an optimum value of 6.12NTU at an optimum dose of 0.03g/L and a turbidity reduction of was obtained 66.74%, alongside an improvement in other water parameters such as Conductivity, dissolved oxygen and total dissolved solids. This result proves the effectiveness of Delonix regia as a natural coagulant in treating low turbid water. However, treatment with Delonix regia is not sufficient to improve the quality of low turbid water to WHO acceptable limits for potable water.