scholarly journals Ecotoxic effects of Hexavalent Chromium on biochemical parameters of Lemna minor and its bioaccumulation by Lemna minor

Author(s):  
Neetu Tewari ◽  
P Vasudevan

Untreated effluents when discharged into the environment possess potential health hazards to almost all forms of life. Many plants are being used to study the toxic effects of heavy metal pollution on plants. However, aquatic plants like Lemna minor are widely used. Their wide distribution, small size, ease of culture and rapid reproduction rates are the attributes that have led to their use as a cost-effective test model. In the present study batch experiments were conducted to study the effects of Cr (VI) and Cr (III) on biochemical content of Lemna minor. Ecotoxic effect of Cr (VI) and Cr (III) on growth, amount of total chlorophyll, total soluble starch, total free sugar, total soluble proteins and total free amino acids was studied in the present research. It was found that Cr (III) at all the concentrations did not affect any of the study parameters significantly. However, Cr (VI) at and beyond 10 mg/l significantly affected the studied parameters. Bioaccumulation of Cr (VI) and Cr (III) by Lemna minor was also investigated. Substantial Cr (VI) accumulation was detected in Lemna minor while it accumulates very low amounts of Cr (III). Aquatic plant-like Lemna bioaccumulate high amounts of Cr (VI) thus it may help in the treatment of polluted water bodies.

2020 ◽  
Vol 12 (5) ◽  
pp. 1927 ◽  
Author(s):  
Shafaqat Ali ◽  
Zohaib Abbas ◽  
Muhammad Rizwan ◽  
Ihsan Zaheer ◽  
İlkay Yavaş ◽  
...  

Heavy-metal (HM) pollution is considered a leading source of environmental contamination. Heavy-metal pollution in ground water poses a serious threat to human health and the aquatic ecosystem. Conventional treatment technologies to remove the pollutants from wastewater are usually costly, time-consuming, environmentally destructive, and mostly inefficient. Phytoremediation is a cost-effective green emerging technology with long-lasting applicability. The selection of plant species is the most significant aspect for successful phytoremediation. Aquatic plants hold steep efficiency for the removal of organic and inorganic pollutants. Water hyacinth (Eichhornia crassipes), water lettuce (Pistia stratiotes) and Duck weed (Lemna minor) along with some other aquatic plants are prominent metal accumulator plants for the remediation of heavy-metal polluted water. The phytoremediation potential of the aquatic plant can be further enhanced by the application of innovative approaches in phytoremediation. A summarizing review regarding the use of aquatic plants in phytoremediation is gathered in order to present the broad applicability of phytoremediation.


2020 ◽  
Vol 6 (3) ◽  
pp. 180-191
Author(s):  
Kavitha Chandrasekaran

Background:: In the long run, synthetic tints were found to be harmful to the chemicals. As a result natural tints have come to be used for their many intrinsic values. The main reason being, then availability of local plants as the main source of natural colorants. Their easy availability in the country being zero cost – effective and planted for other purposes are the main reasons for utilizing them as natural tints. Almost all the parts of the plants, namely stem, leaves, fruits, seeds, barks etc. are used for extracting natural colour. In addition, they are antimicrobial antifungal, insect – repellant deodorant, disinfectant having medicinal values. Methods:: Sweet Indrajao leaves were cleaned by washing with water and dried under direct sunlight and ground as fine powder. A fine strainer was used to remove the wastages. After all these processes, 1-kilogram leaves weighed 318 grams. Then, it is put in 75% ethanol 25% water and heated in a breaker which in kept over a water bath for 2 hours. After this, the contents were filtered and kept in a separate beaker. Bleached fleece draperies stained with stain extract were made to become wet and put into different stain baths which contain the required amount of stain extract and water. Acetic acid was added to it after 20 minutes. The fleece drapery was stained for about one hour at 60oC. The draperies thus stained were removed, squeezed, and put to treatment with metal salts without washing. Different metal salts were used for the treatment using 3% of any one of the chemical mordants like alum, stannous chloride, potassium dichromate, ferrous sulphate, nickel sulphate, copper sulphate and natural mordants such as myrobolan, turmeric, cow dung, Banana sap juice at 60oC for 30 minutes with MLR of 1:30. The stained draperies were washed repeatedly in all the three methods in water and dried in air. At last, the stained draperies were put to soap with soap solution at 60oC for 10 minutes. The draperies were repeatedly washed in water and dried under the sun. Results:: Sweet Indrajao leaves discharged colour easily in alcoholic water. The fleece draperies were stained with chemical and natural mordants. It was observed that the stain uptake was found to be good in post-mordanting method. Ultrasonication has clearly improved the stainability of the draperies at pH 3 and 3.5 values. The pH decreases the stain ability under both Conventional and Ultrasonic conditions. The colour strength increases with an increase in staining temperature in both cases of US and CH methods. Conclusion:: Sweet Indrajao.L has been found to have good ultrasonic potential as a stain plant. The stain uptake as well as the fastness properties of the fleece drapery were found to enhance when metal mordant was used in conjugation with ultra-sonication for the extract of Sweet Indrajao. It was also found that the enhancement of staining ability was better without mordant draperies. The dye extract showed good antibacterial activity against the three bacterial pathogens. Among the three bacterial pathogens, dye extract showed more effective against Escherichia coli pathogens and dye extract showed more effective against Aspergillus pathogens. Hence, the ultrasonic method of drapery staining may be appropriate and beneficial for society at large in future.


2021 ◽  
Vol 11 (4) ◽  
Author(s):  
Theresa C. Umeh ◽  
John K. Nduka ◽  
Kovo G. Akpomie

AbstractDeterioration in soil–water environment severely contributed by heavy metal bioavailability and mobility on soil surface and sub-surface due to irrational increase in wastewater discharge and agrochemical activities. Therefore, the feasibility of adsorption characteristics of the soil is paramount in curbing the problem of micropollutant contamination in the farming vicinity. Soil from a farming site in a populated area in Enugu, Nigeria was collected and tested to measure the lead and cadmium contents using atomic absorption spectrophotometer (AAS). The adsorption potency of the ultisol soil was estimated for identifiable physicochemical properties by standard technique. The mean activity concentration of Pb2+ and Cd2+ was 15.68 mg/kg and 3.01 mg/kg. The pH, temperature, metal concentration and contact time adsorptive effect on the Pb2+ and Cd2+ uptake was evaluated by batch adsorption technique. The Langmuir, Freundlich and Temkin models were fitted into equilibrium adsorption data and the calculated results depict a better and satisfactory correlation for Langmuir with higher linear regression coefficients (Pb2+, 0.935 and Cd2+, 0.971). On the basis of sorption capacity mechanism of the soil, pseudo-second-order model best described the kinetics of both metal ions retention process. The results of the present study indicated that the soil being a low cost-effective adsorbent can be utilized to minimize the environmental risk impact of these metal ions.


Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 156
Author(s):  
Lorenzo Clemente ◽  
Sofia Mazzoleni ◽  
Eleonora Pensabene ◽  
Tomáš Protiva ◽  
Philipp Wagner ◽  
...  

The Asian box turtle genus Cuora currently comprises 13 species with a wide distribution in Southeast Asia, including China and the islands of Indonesia and Philippines. The populations of these species are rapidly declining due to human pressure, including pollution, habitat loss, and harvesting for food consumption. Notably, the IUCN Red List identifies almost all species of the genus Cuora as Endangered (EN) or Critically Endangered (CR). In this study, we explore the karyotypes of 10 Cuora species with conventional (Giemsa staining, C-banding, karyogram reconstruction) and molecular cytogenetic methods (in situ hybridization with probes for rDNA loci and telomeric repeats). Our study reveals a diploid chromosome number of 2n = 52 chromosomes in all studied species, with karyotypes of similar chromosomal morphology. In all examined species, rDNA loci are detected at a single medium-sized chromosome pair and the telomeric repeats are restricted to the expected terminal position across all chromosomes. In contrast to a previous report, sex chromosomes are neither detected in Cuoragalbinifrons nor in any other species. Therefore, we assume that these turtles have either environmental sex determination or genotypic sex determination with poorly differentiated sex chromosomes. The conservation of genome organization could explain the numerous observed cases of interspecific hybridization both within the genus Cuora and across geoemydid turtles.


2021 ◽  
Vol 277 ◽  
pp. 04003
Author(s):  
Ayu Widya Utami ◽  
Dwi Nowo Martono ◽  
Haruki Agustina

West Tarum Canal (WTC) is a canal that drains raw water from the Jatiluhur Dam. Nearly 81% of the raw water for drinking water used by Jakarta’s people comes from this canal. However, various land uses such as agriculture, industry, settlements, and infrastructure development impact WTC’s water quality. This research aims to assess WTC’s water quality in 2016-2020 based on water quality standards set by the Government and using the STORET method. The results of this research indicate that the concentrations of TDS (142-351 mg/L), Fe (0.1-0.15 mg/L), Mn (0.03-0.1 mg/L) are meet the standards, while DO (3.6-4.9 mg/L), BOD (4-10 mg/L), COD (13-30 mg/L) are not meet the standards. Almost all monitoring points have pH values between 5.75-7.68 that are meet the standards. The STORET score of WTC is from -26 to -38 with an average of -30, which indicates that WTC’s water quality is moderately polluted. Water contamination in WTC will burden the drinking water processing and ultimately affect the community’s ability to pay for drinking water. This research also shows the need for integrated management of WTC from upstream to downstream and the need to increase collaboration between stakeholders in carrying out this management.


2021 ◽  
pp. 218-245
Author(s):  
R. Jasrotia

The decreasing levels of consumable water on earth have been a serious issue and this issue makes the researchers and scientists develop new technologies for the purification of polluted water. Several reports have been carried on wastewater remediation by utilizing spinel ferrite-based nanoparticles and their composites. The spinel ferrites-based nanoparticles utilized for wastewater treatment was cost effective, chemically stable, easily retrieved and reusable. The present work addresses the various fabrication techniques for the preparation of spinel ferrite-based nanoparticles and their utilization for the removal of organic and inorganic pollutants through the adsorption paths.


2021 ◽  
Author(s):  
Hamed Azarbad ◽  
Julien Tremblay ◽  
Luke D. Bainard ◽  
Etienne Yergeau

AbstractNext-generation sequencing is recognized as one of the most popular and cost-effective way of characterizing microbiome in multiple samples. However, most of the currently available amplicon sequencing approaches are inherently limited, as they are often presented based on the relative abundance of microbial taxa, which may not fully represent actual microbiome profiles. Here, we combined amplicon sequencing (16S rRNA gene for bacteria and ITS region for fungi) with real-time quantitative PCR (qPCR) to characterize the rhizosphere microbiome of wheat. We show that the increase in relative abundance of major microbial phyla does not necessarily result in an increase in abundance. One striking observation when comparing relative and quantitative abundances was a substantial increase in the abundance of almost all phyla associated with the rhizosphere of plants grown in soil with no history of water stress as compared with the rhizosphere of plants growing in soil with a history of water stress, which was in contradiction with the trends observed in the relative abundance data. Our results suggest that the estimated absolute abundance approach gives a different perspective than the relative abundance approach, providing complementary information that helps to better understand the rhizosphere microbiome.


Author(s):  
Lorena Lanthemann ◽  
Sofia van Moorsel

Duckweeds (Lemnaceae) are increasingly studied for their potential for phytoremediation of heavy-metal polluted water bodies. A prerequisite for metal removal, however, is the tolerance of the organism to the pollutant, e.g., the metal zinc (Zn). Duckweeds have been shown to differ in their tolerances to Zn, however, despite them most commonly co-occurring with other species, there is a lack of research concerning the effect of species interactions on Zn tolerance. Here we tested whether the presence of a second species influenced the growth rate of the three duckweed species Lemna minor, Lemna gibba, and Lemna turionifera. We used four different Zn concentrations in a replicated microcosm experiment under sterile conditions, either growing the species in isolation or in a 2-species mixture. The response to Zn differed between species, but all three species showed a high tolerance to Zn, with low levels of Zn even increasing the growth rates. The growth rates of the individual species were influenced by the identity of the competing species, but this was independent of the Zn concentration. Our results suggest that species interactions should be considered in future research with duckweeds and that several duckweed species have high tolerance to metal pollution, making them candidates for phytoremediation efforts.


2020 ◽  
Vol 5 (4) ◽  
pp. 1237-1252
Author(s):  
Paul Pirrie ◽  
David Campos-Gaona ◽  
Olimpo Anaya-Lara

Abstract. Multi-rotor wind turbines (MRWTs) have been suggested in the literature as a solution to achieving wind turbine systems with capacities greater than 10 MW. MRWTs utilize a large number of small rotors connected to one support structure instead of one large rotor with the aim of circumventing the square cube law. Potential benefits of MRWTs include cost and material savings, standardization of parts, increased control possibilities, and improved logistics for assembly and maintenance. Almost all previous work has focused on mechanical and aerodynamic feasibility, with almost no attention being paid to the electrical systems. In this research eight different topologies of the electrical collection network for MRWTs are analysed to assess which are the most economically and practically viable options. AC and DC collection networks are presented in radial, star, cluster and DC series topologies. Mass, capital cost and losses are estimated based on scaling relationships from the academic literature and up-to-date commercial data. The focus of this study is the assessment of the type of electrical collector topology, so component type and voltage level are kept consistent between topology designs in order to facilitate a fair comparison. Topologies are compared in terms of four main criteria: capital cost, cost effectiveness, total mass and reliability. A comparison table is presented to summarize the findings of the research in a convenient way. It is found that the most cost-effective solutions are the AC radial and AC star topologies, with the least cost-effective being the DC series–parallel and DC cluster topologies. This is due to the high cost of DC–DC converters and DC switchgear along with the lower efficiency of DC converters. Radial designs perform best in terms of efficiency and annual energy capture. DC systems achieve a slightly lower nacelle mass compared to their equivalent AC systems. DC topologies are generally found to be more expensive when compared to their AC counterparts due to the high cost of DC–DC converters and DC switchgear. Star topologies are considered to have the best reliability due to having no shared equipment. The most suitable collection topology for MRWTs is shown to be of the star type, in which each turbine is connected to the step-up transformer via its own cable.


Author(s):  
Sergey Nogin ◽  
Jânio Monteiro ◽  
Sergio Gómez Melgar ◽  
José Peyroteo ◽  
António Mortal ◽  
...  

Tourists today are more likely to be concerned with the environment and greener lifestyle choices. In this context, a green flagship of some hotels can be an important selection criteria at the time of selecting one. In the near future, buildings should become nearly zero energy, consuming as low as possible and producing almost all the energy they need, using renewable energy sources. To achieve this goal, hotel buildings need to pass through a transformation process that will make them more efficient. In this process, a decision support platform would be important to help hoteliers monitor their energy consumption, identify which points are consuming more than expected, decide which investments are more cost effective and manage their equipment in an optimum way. This chapter describes the challenges involved in developing such a platform, covering several research and development fields, including Internet of Things networks, ICT, Smart Grids, Renewable Energy, Energy efficiency, as well as algorithms for machine learning and optimization.


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