Environmental Engineering
F.M. Muvea; G.M. Ogendi; S.O. Omondi
Abstract
The use of constructed wetlands for purifying pre-treated wastewater is a cost effective technology that has been found to be more appropriate for many developing countries. The technology is also environmentally friendly with the wetlands being habitats for many water birds and other aquatic organisms. ...
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The use of constructed wetlands for purifying pre-treated wastewater is a cost effective technology that has been found to be more appropriate for many developing countries. The technology is also environmentally friendly with the wetlands being habitats for many water birds and other aquatic organisms. This study assessed nutrient removal efficiency of two floating macrophytes (Lemna minor and Azolla pinnata). The data generated was analyzed using both descriptive and inferential statistics. The significance level was maintained at 0.05. The results showed that the wastewater physicochemical parameters did not vary during the study period. The concentrations of nitrites and nitrates increased over the experimental period in all the treatments (Azolla pinnata, Lemna minor and control), and the increase between the sampling occasions was statistically significant for the two nutrients (Nitrates: F=24.78, P= 0.00; Nitrates: F=198.26, P= 0.00). To the contrary, in all the treatments the concentrations of ammonia, total phosphorous, soluble reactive phosphorous and total nitrogen, decreased over the experimental period. The decrease in concentration for these nutrients between the sampling occasions was statistically significant (ammonia: F=195.57, p= 0.00; total phosphorous: F= 56.50, p= 0.00; soluble reactive phosphorous: F= 37.11, p= 0.00; total phosphorous: F= 104.025, p= 0.00). Azolla pinnata proved to be better than Lemna minor in the uptake of the nutrients particularly for the soluble reactive phosphorous (F= 35.18, P= 0.044). We conclude that the two macrophytes are good for wastewater treatment. It is recommended introduction and/or multiplication of Azolla pinnata in the constructed wetlands meant for wastewater treatment especially within the tropics.
Environmental Engineering
S. Łęgowik-Świącik
Abstract
In this study, the relationships between two variables: the strategy of sustainable development and the efficiency of waste management in the commercial power industry company have been subjected to discussion. The basis for the explanation of the aforementioned relationships is the assumption that the ...
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In this study, the relationships between two variables: the strategy of sustainable development and the efficiency of waste management in the commercial power industry company have been subjected to discussion. The basis for the explanation of the aforementioned relationships is the assumption that the level of implementation of the strategy of sustainable development is expressed through capital expenditures incurred on the implementation of modern tools of waste management. On the other hand, the efficiency of waste management in the commercial power industry company is reflected by the level of costs incurred on the storage, transport, and sales of this waste. The whole of the presented considerations has been divided into two basic parts, theoretical and empirical. The first part of the paper exposes the strategic dimension of the concept of sustainable development taking into account the economic and environmental efficiency of waste management achieved due to the use of modern management tools. The considerations presented in the second part constitute the response to the research question. The empirical part includes the identification of waste in the commercial power industry company in Poland and the research aiming at the cognition and assessment of relationships between the efficiency of waste management and the implementation of the strategy of sustainable development in the surveyed company. The publication increases the understanding of the coexistence of the strategy of sustainable development and the efficiency of waste management in the company of the commercial power industry operating in Poland, with particular emphasis on waste reduction and the possibility of its redevelopment. The research methods applied to accomplish the objective are literature studies, case study, descriptive analysis, trend analysis, and the Pearson correlation coefficient.
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