Novel Composite Materials for Lake Restoration: A New Approach Impacting on Ecology and Circular Economy

Abstract

The purpose of this study is to promote a new way of application composite materials to restore eutrophic waters. A new sustainable way of application is based on the “teabag” method, in which materials were placed in water-permeable bags and immersed in the water column in order to sorb phosphate—one of the main contributory element for the eutrophication problem. Particularly, the two composites materials of Phoslock™ (lanthanum-modified bentonite, LMB) and Bephos™ (Fe-modified bentonite, f-MB) were tested and bench-scale batch experiments were employed to investigate their sorption efficiency in the forms of slurry and teabag. The adsorption kinetics and the relevant adsorption isotherms were deployed, while the effect of the materials on turbidity and their aging were also investigated. Experimental results showed that Phoslock™ and Bephos™ (as teabag), being applied at initial concentration range: 0.05–5 mg/L, they sustained a maximum adsorption capacity of 7.80 mg/g and 25.1 mg/g, respectively, which are considered sufficient rates for P concentrations reported at natural aquatic ecosystems. At the same time this new method did not cause turbidity in the water column, since the material was not released into the water, thus, preventing potential harmful consequences for the living organisms. Moreover, the “teabag” method prevents the material to cover the lake bottom, avoiding the phenomenon of smothering of benthos. Βy teabag method, the materials can be collected for further applicability as soil improver or crops fertilizer. Finally, it was argued that the possibility to recycle LMB and f-MB materials for agricultural use is of paramount importance, sustaining also positive impacts on sustainable ecology and on the routes of circular economy (CE).

Economic Valuation of Lake Tempe Area Resources in Wajo Regency; A Socio-Economic and Ecological Approach

“…However, agriculture around the lake holds great potential for the people around the lake. Source: Primary data output after processing, 2020; (Darsam, 2020) This is in line with previous findings that the ecological balance of the lake can be a trigger for the fertility of the land around the lake so that it can provide direct benefits for agricultural activities, which are able to support the surrounding community ( 2020; Barros et al, 2020;Jindo et al, 2020;Murphy, 2020;Ngondjeb and Ayuk, 2021;Panagopoulos and Dimitriou, 2020;Polontoh et al, 2019;Zamparas et al, 2020;Zheng et al, 2020).…”

“…Mainly, for fishery commodities. People's dependence on this is getting higher from time to time (Alaye et al, 2020;Barros et al, 2020;Jindo et al, 2020;Murphy, 2020;Ngondjeb and Ayuk, 2021;Panagopoulos and Dimitriou, 2020;Polontoh et al, 2019;Zamparas et al, 2020;Zheng et al, 2020).…”

Green productivity and undesirable outputs in agriculture: a systematic review of DEA approach and policy recommendations

“…However, resource use is distinguished into four categories: usage of material, water, land, energy, and climate change. Modern agriculture faces significant challenges, including extreme water supply and fertiliser impacts (Zamparas et al, 2019a), deforestation (Tsiantikoudis et al, 2019), GHG emissions (Kyriakopoulos & Chalikias, 2013, Kyriakopoulos et al, 2010, soil erosion, eutrophication (Zamparas et al, 2019b), and water pollution ( (Zamparas et al, 2020). Also, resource use efficiency means allocating and using various scarce resources to reach benefits.…”

Investigating the Human Impacts and the Environmental Consequences of Microplastics Disposal into Water Resources

“…It is also imperative that experimental results should be confirmed by model-based studies, investigating the extent to which MP concentrations are negligible, or not, for the overall pollutant uptake of freshwater indicators, such as zooplankton species, with water as an additional uptake pathway [50]. Such research paths can reveal the contradictions between the level and the severity of MPs presented in water sources, thus, encouraging future studies to: (a) further and fully investigate how MPs are considered as dominant anthropogenic pollutants of ecological risk, (b) support the primary scope of science and society in tackling such a global environmental issue in the future [45], (c) investigate the ways in which MPs pollution and sediment resuspension in shallow lakes are affecting climate change, eutrophication, and resuspension [63][64][65], emphasizing the role of MPs in intensifying the two environmental effects of climate change and eutrophication [66][67][68][69], (d) reinvent plastics production under the environmental considerations and the social provisions for radical modes of eco-design plastics production, biodegradable plastics production, as well as a circular thinking of manufacturing production, making the used plastic products able to undergo a second round of use after recovering and recycling. Moreover, legislative framework updating and WWTPs' adaptation to the aforementioned directions should be shown to be vital tools to endorse those safety regulations of MP pollution decrease in the contexts of circular economy and the employment of effective practices to control the plastic waste crisis [70,71].…”