Phycoremediation potential and agar yield of red macroalgae (Gracilaria corticata) against HEDP (hydroxyethylidene diphosphonic acid) and CAPB (cocoamidopropyl betaine) detergents and the heavy metal pollutants

The discharge of raw industrial, agricultural, and domestic wastes leads to an increase in heavy metal (HM) burden and detergents in aquatic environs, which can have destructive effects on aquatic organisms. Agarophyte Gracilaria corticata, a major component of seaweed flora of the southern coast of Iran (Bushehr) that contains agar and red pigments, is one of the economically valuable red marine algae. Agar is one of the important polysaccharides with high economic value, widely used in pharmaceutical, medicinal, and cosmetic product manufacturing industries. The aim of this work was to investigate the effect of 5 HMs and two common surfactants in household and industrial detergents on the agar yield, appearance color, and the red algae's phycoremediation potential against HMs. The metal ions were Zn(II), Cu(II), Ni(II), Mn(II), and Cr(VI), and the surfactants were HEDP and CAPB. The analysis results of samples cultured for 60 days in seawater and polluted environments showed that G. corticata can accumulate copper and nickel. In the presence of detergents without HMs, the amount of extracted agar significantly increased compared to the control sample with no change in algae color. But with increasing concentration of HMs, the amount of agar in seaweed samples decreased significantly, and the algae discolored from red to dark green or yellowish-green color (signs of death in the algae). These results show that increasing of HM pollution and detergents can lead to toxicological effects and reduce the species diversity of red seaweeds in the future.

Assessment of tea saponin and citric acid-assisted phytoextraction of Pb-contaminated soil by Salvia virgata Jacq

The present study, investigated the influence of the natural tea saponin (TS) obtained by microwave-assisted extraction and citric acid (CA) by commercially enhancing lead ion (Pb(II)) uptake by Salvia virgata Jacq. The Pb(II) tolerance was compared, and the growth of plants and Pb(II) accumulation characteristics of S. virgata with chemical agents TS and CA were studied for their phytoextraction potential of Pb(II) from artificially contaminated soil of 0-100 mg kg^-1 different concentrations under pot conditions. The different morphophysiological parameters of S. virgata such as growth, biomass, chlorophylls, and carotenoids were significantly changed under different Pb(II) stress and TS and CA concentrations. To evaluate the removal efficiency of the studied plant, the bioconcentration factor (BCF) or enrichment coefficient (EC), translocation factor (TF), and tolerance index (TI) values were also calculated and compared with the control. Phytotoxic effects were observed at 100 mg kg^-1; added Pb(II) treatments caused significant decreases of 33.05% in the biomass of S. virgata compared to the control. All the obtained results showed that the concentrations of Pb(II) being compared revealed a highest uptake (286 ± 5.2 mg kg^-1) of 100 mg kg^-1. The concentration of available Pb(II)-assisted TS and CA increased by 9.1-28.4% compared to the control. Based on these findings, S. virgata might be cultivated and used as a hyperaccumulator in the removal of Pb(II) from the contaminated soils, and appropriate application of TS and CA can enhance phytoremediation of Pb(II)-contaminated soil by other hyperaccumulator plants.

Multielement Determination in Turmeric (Curcuma longa L.) Using Different Digestion Methods

The antioxidant, anti-inflammatory and antiseptic properties of turmeric (Curcuma longa L.) derive from its rich nutritional composition making it interesting for medicinal uses, besides being used as spice in cooking. To complete the picture on the composition of turmeric, not only the organic compounds need to be known, but also the elemental composition covering essential and potentially toxic elements. The samples were digested in a microwave assisted digestion system using different reagent mixtures. The best digestion mixture was semi-concentrated nitric acid combined with hydrogen peroxide. After optimization of the sample preparation method, the contents of Ag, Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Se, Sr, Te, Tl, V and Zn in curcuma were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), as well as by inductively coupled plasma mass spectrometry (ICP-MS). Even if the general composition found is in line with the scarce data in literature, clear differences can be seen between the analyzed samples, considering provenience, production procedures, and harvesting year as potential influencing factors. Whereas all samples contained less As and Pb than regulated by WHO, one limit exceeding was found for Cd.

Fabrication of silk sericin-anthocyanin nanocoating for chelating and saturation-visualization detection of metal ions

Silk sericin (SS) is a natural water-soluble protein with the potential to chelate metal ions via its polar groups. However, the difficulty of identifying the saturation of SS limits its application as filter films. One solution is to construct SS filter films with an indicator to reflect the degree of saturation of silk sericin. Hence, the nanocoating consisting of co-assembled SS protein and anthocyanin (C3G) nanoparticles is designed, constructed, and characterized to chelate metal ions with a saturation-visualization detection behavior. Here, metal ions Zn²⁺ and Al³⁺ are chosen as models to explore the chelating ability of SS and indicator behaviors of C3G, which could indicate the saturation degree of SS. Interestingly, after the saturation of SS in the solution and filter film situations, the visible color progressively shifts from pink to blue (Zn²⁺) or violet (Al³⁺), with the corresponding redshift of UV-Vis absorbance of C3G. Remarkable removal effectiveness of Zn²⁺ and Al³⁺, namely 93.16% and 53.97%, as well as an evident saturation-visualization detection, were identified by filter paper films with the nanocoating. Our research provides a fresh viewpoint for designing SS filter films that could effectively remove metal ions while enabling real-time viewing.

The Effect of Paper on the Detection Limit of Paper-Based Potentiometric Chloride Sensors

While paper is an excellent material for use in many other portable sensors, potentiometric paper-based sensors have been reported to perform worse than conventional rod-shaped electrodes, in particular in view of limits of detection (LODs). Reported here is an in-depth study of the lower LOD for Cl^- measurements with paper-based devices comprising AgCl/Ag transducers. Contamination by Cl^- from two commonly used device materials─a AgCl/Ag ink and so-called ashless filter paper─was found to increase the concentration of Cl^- in paper-contained samples far above what is expected for the spontaneous dissolution of the transducer's AgCl, thereby worsening lower LODs. In addition, for the case of Ag⁺, the commonly hypothesized adsorption of metal cations onto filter paper was found not to significantly affect the performance of AgCl/Ag transducers. We note that in the context of chemical analysis, metal impurities of paper are often mentioned in the literature, but Cl^- contamination of paper has been overlooked.

Adsorption of N,N,N′,N′-Tetraoctyl Diglycolamide on Hypercrosslinked Polysterene from a Supercritical Carbon Dioxide Medium

The work considers for the first time the preparation of sorbents based on hypercrosslinked polysterene (HCP) and chelating agent N,N,N′,N′-tetraoctyl diglycolamide (TODGA) by impregnation in the supercritical (SC) CO₂ medium. Such sorbents can be applied for further isolation and separation of lanthanides, actinides and other metals. They are usually prepared by impregnation in toxic organic solvents (e.g., methanol, dichloromethane). Our study shows that application of SC CO₂ instead of organic solvents can significantly speed up the impregnation, perfom it in one stage and make the process more eco-friendly. At the same time, the obtained sorbents are close in their parameters to the classical ones. This article presents the results of measuring the TODGA adsorption isotherms on two HCP sorbents (MN202 and MN270) on a wide range of SC fluid parameters. Adsorption measurements were carried out using on-line supercritical fluid chromatography and gravimetry. Based on the sorption capacity parameter, MN202 sorbent was selected as the better carrier for TODGA. An impregnation temperature increase within the range 313–343 K in isochoric conditions (ρ = 0.780 g/mL) reduces the maximum of TODGA adsorption from ~0.68 mmol/g to ~0.49 mmol/g.

Enhancement of cadmium uptake by Amaranthus caudatus, an ornamental plant, using tea saponin

In this study, tea saponin (TS) was extracted from tea camellia seed by microwave-assisted extraction. The potential of TS was compared with ethylenediaminetetracetic acid (EDTA), which is used as a common chemical agent to enhance uptake of cadmium (Cd) by Amaranthus caudatus, an ornamental plant in the natural vegetation of Turkey under pot conditions. The enrichment coefficient (EC) and translocation factor (TF) values were calculated to evaluate the removal efficiency of the TS and EDTA. The results showed that an increase in both TS and EDTA concentration significantly increased Cd uptake by A. caudatus, accumulating Cd in different parts of the plant. Higher EC and TF values obtained from stems, leaves, and inflorescences of A. caudatus showed that this plant might be cultivated and used as a hyperaccumulator in the uptake of Cd from the Cd contaminated soils. Thus, the present technique can efficiently reduce the metal load in the food chain; hence, it could be applied in catchment areas of urban cities where Cd contamination has become an unavoidable factor.

Accumulation of heavy metals in water, sediments and wetland plants of kizilirmak delta (samsun, Turkey)

In this study, concentrations of heavy metals (Fe, Mn, Ni, Co, Zn, Cu, and Pb) were measured in water bodies including streams, bottom sediments and various wetland plants of Kızılırmak Delta. Kızılırmak Delta is one of the largest and the most important natural wetlands in Turkey and has been protected by Ramsar convention since 1993. The heavy metal concentrations in water were found lower than that of national standards for protected lakes and reserves. In bottom sediments and wetland plants, however, the accumulated amounts of different heavy metals varied in the following order: Fe>Mn>Zn>Ni>Co>Cu>Pb, and Fe>Mn>Zn>Ni>Co respectively. Heavy metal uptake of Hydrocharis morsus-ranae and Myriophyllum verticillatum plants among others were found far above the toxic levels and they might be used as bio-indicators and heavy metal accumulators in polluted natural areas.

Effect of EDTA and Tannic Acid on the Removal of Cd, Ni, Pb and Cu from Artificially Contaminated Soil by Althaea rosea Cavan

In this study an ornamental plant of Althaea rosea Cavan was investigated for its potential use in the removal of Cd, Ni, Pb and Cu from an artificially contaminated soil. Effect of two different chelating agents on the removal has also been studied by using EDTA (ethylenediaminetetracetic acid) and TA (tannic acid). Both EDTA and TA have led to higher heavy metal concentration in shoots and leaves compared to control plants. However EDTA is generally known as an effective agent in metal solubilisation of soil, in this study, TA was found more effective to induce metal accumulation in Althaea rosea Cavan under the studied conditions. In addition to this, EDTA is toxic to some species and restraining the growth of the plants. The higher BCF (Bio Concentration Factor) and TF (Translocation Factor) values obtained from stems and leaves by the effects of the chemical enhancers (EDTA and TA) show that Althaea rosea Cavan is a hyper accumulator for the studied metals and may be cultivated to clean the contaminated soils.