•Water pollution has become a worldwide concern because the demand for fresh water is increasing exponentially, while its availability is under threat. There is a societal need to treat the ...wastewater to save our freshwater bodies from becoming polluted.•This review mainly delves into recent developments in heavy metal ions detection via nanosensor and natural remediation technologies for wastewater treatment.•The review begins with an introduction to heavy metal pollution, nanotechnology and its role in water treatment, and the green synthesis of nanoparticles. Then it covers the detection of toxic metal ions using green synthesized nanosensors.
Water pollution has become a worldwide concern because the demand for fresh water is increasing exponentially, while its availability is under threat. There is a societal need to treat wastewater to save our freshwater bodies from becoming polluted. Although several techniques are acquirable in the market to purify polluted water, such as reverse osmosis, ion exchange, membrane process, etc., they are expensive. This review delves into recent developments in heavy metal ions detection via nanosensors and natural remediation technologies for wastewater treatment. Current trends of plant utilization in NPs synthesis for heavy metal ions sensing and natural remediation processes are focused on and addressed ahead. A hypothetical model using first nanosensor to detect heavy metal ions and later natural remediation techniques for wastewater treatment has been put forward. The proposed model facilitated by further research inputs may pave the way for potential and efficient wastewater treatment. This review begins with an introduction to heavy metal pollution, nanotechnology, its role in water treatment and green synthesis of nanoparticles. Then, it covers the detection of toxic metal ions using green synthesized nanosensors. Followed by recent advancements in natural remediation technologies such as waste stabilization ponds, floating rafts, phytoremediation, phytofilters and dendroremediation.
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Composite materials have become a research hotspot in the field of vibration and noise reduction for their high strength, high damping, and other outstanding mechanical properties in recent years. In ...this paper, the effect of laminated materials on the dynamic performance of floating rafts is investigated based on modal superposition theory using the finite element method. The detailed derivation of the modal superposition theory was made, and taking T700 fiber-reinforced composite material as an example the damping effect of the floating raft structure in three cases was discussed: whether the composite material is laid or not, different layup angles, and different layup positions. The research shows that laying composite materials can improve damping effect of the floating raft and the changes in both the laying angle and the laying position will affect its dynamic performance. Moreover, the damping performance of the structure is inversely correlated with its stiffness within a certain range.
Artificial nesting sites with floating platforms may effectively support local breeding populations of waterbirds (enhancing productivity and survival) when natural sites are unavailable. In this ...study, we installed three artificial floating nest platforms (one in 2017, two in 2020) and we evaluated their use as a conservation measure for the common tern Sterna hirundo breeding at a RAMSAR site in Northern Poland with limited natural nesting habitat. We analyzed local population dynamics based on direct census in the study area from 2013 to 2021 and using data from literature dating back to 1925, with emphasis on the effects of three artificial nest platforms. We found that the local common tern population exhibited steep decline during the period 1999-2021 (−92%). Birds accepted artificial nesting platforms in the first year of their installation. The number of pairs breeding in artificial nests in 2017-2021 made up 53-100% of the breeding population in the study area. The nest density, clutch size and mean breeding output were similar in all platforms during all seasons. In 2020, the water level in the lake rapidly increased (ca 50 cm in 24 h) and completely destroyed common tern nests in the natural islets, while the floating platforms were the only places in the nature reserve where common terns were able to nest and breed successfully. We conclude that artificial breeding platforms may be a good conservation measure for common terns in natural areas with limited access to breeding habitat (but with optimal foraging areas). Based on our experiences from the present case study and on experience of other authors we propose recommendations for constructing, placing, and maintenance of nest platforms for common terns.
The American mink (
) was introduced to Italy for the fur farming industry during the 1950s. The first feral mink were observed in the 1980s in the northern regions of Veneto, Friuli Venezia Giulia ...and Emilia Romagna. In this work, we investigated the distribution of mink in Friuli Venezia Giulia, more than 10 years after the last extensive release of farmed animals which happened in this region in 2003. Results indicate that American mink has naturalized in the region and populations are still localized along some tributaries of the upper Tagliamento catchment.
Identifying and mapping new sites of establishment of alien species is a research priority as it helps to provide timely management actions. In Italy, feral populations of the American mink Neovison ...vison, a semi-aquatic mustelid native to North America, have been present since the 1980s in the north of the country and on the island of Sardinia. Recently, mink sightings were reported also in central Italy, in the Lazio region. However, no information existed on the consistency and distribution of this population. The aims of this study were to (1) assess the presence and distribution of the American mink in the Lazio region, (2) identify the possible sources of individuals and (3) provide a evaluation of the efficacy of the different techniques adopted. Data on the distribution of the American mink were obtained during 2008 by gathering bibliographical data, by interviewing the stakeholders, and by carrying out field surveys using camera traps, hair tubes, floating rafts and surveying for signs of presence. Floating rafts proved to be the most successful field method amongst the ones adopted in this study. We recorded the American mink at several sites within the Aniene River catchment and its presence seemed restricted only to this catchment within the Lazio region. We found 12 mink farms in the Lazio region, one of which is still active; occasional escapes or liberations have taken place in 11 of these farms. Given the presence of mink farms and the restricted distribution of the feral mink population in the Lazio region, there are at least two management actions that should be undertaken rapidly: (1) minimising escapes from the remaining mink farm through actions with the farmer and the regional authorities; (2) implementing an eradication program for the Aniene population.
The commercial cultivation of Kappaphycus alvarezii is the main source of raw material for the carrageenan industry. Brazilian commercial farming uses floating rafts that serve as substrata for ...fouling organisms that may affect production of the carrageenophyte seedlings. The aim of this work was to identify and quantify the biofouling on floating rafts at Sepetiba Bay, Rio de Janeiro State (23° 02′ 25″ S and 43° 53′ 39″ W), and to evaluate seedling damage caused by epibionts and endobionts. Samples were collected from August 2006 to August 2007. In each assessment, organisms contained in random sampling areas of 18 quadrats of 0.10 m2 (n = 18) were removed from floating rafts. K. alvarezii seedling samples were collected to verify the presence of epibionts or endobionts (n = 30). Twenty-four taxa belonging to seven groups of animals and three groups of seaweed were found. The percentage occurrence estimated 13 dominant organisms and amphipod tubes: e.g., Chondracanthus tedii, Cladophora vagabunda, Gracilariopsis tenuifrons, Hypnea spinella, Hypnea musciformis, Hincksia mitchelliae, Spyridia spp., Ulva spp., Bowerbankia sp., Bugula neritina, Botryllus sp., Haplosclerida sp., and Perna perna. Richness, equitability, diversity, and total biomass varied significantly during the study period (p < 0.001). There was a tendency for higher biomass values in August 2007. After 6 months, epibionts (i.e., Chlorophyta, Rhodophyta, Chordata, Cnidaria and Ectoprocta) were found on K. alvarezii seedlings. Endobionts were not found in this study. The biofouling biomass was not found to have a significant effect on K. alvarezii daily growth rate, carrageenan yield, or quality (gel strength and viscosity; p > 0.05).
The possibility of effective treatment of storm-and-industrial wastewater has been shown in principle by using microorganisms, hydrobiocenoses and higher aquatic plants attached to installations in ...the form of floating rafts equipped with VIYA type carriers submerged into water with hydrobionts–water purifiers immobilized on these carriers.
•The HSI-FRA (Hyperspectral remote sensing index for floating-raft aquaculture) has been constructed.•The decision tree model is designed by combining MNDWI and prior knowledge.•The proposed method ...is suitable for extracting floating-raft aquaculture in coastal areas of high suspended matter.
The accurate extraction and mapping of floating raft aquaculture (FRA) is significant to the scientific management and sustainable development of coastal zones. However, the current relevant methods rely on large sample size and complex classifiers, which have poor generalization ability and thus are not suitable for large-scale application. To address these issues, this study proposes a new hyperspectral index based on remote sensing images, namely hyperspectral index for floating raft aquaculture (HSI-FRA). Based on the analysis of the spectral information, the HSI-FRA utilizes four bands at 580 nm, 740 nm, 1040 nm, and 1290 nm, respectively, to enhance the spectral difference between the floating raft aquaculture and the seawater through band calculation, and constructs the extraction index of the floating raft aquaculture. Using the HSI-FRA, a decision tree classification process is carried out to realize the extraction of floating raft aquaculture information. The extraction accuracy in the three study areas of Dayu Bay of Zhejiang Province, Fengwei Town of Fujian Province and Chao'an Bay of Guangdong Province is 94.3%, 95.5% and 91.44%, respectively, which has Larger advantage than those of traditional methods. The experimental results show that the proposed method is simple, fast and accurate at separating the floating raft aquacultures in an offshore complex marine environment.
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