The aim of the study was to screen the waste wood biomass of 10 wood species as biosorbents for synthetic dye Congo Red (CR) removal from water and to single out the most efficient species for ...further batch biosorption experiments. Euroamerican poplar (EP), the most efficient species achieving 71.8% CR removal and biosorption capacity of 3.3 mg g−1, was characterized by field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR). Different factors affecting the biosorption process were investigated: initial biosorbent concentration (1–10 g dm−3), contact time (5–360 min), initial CR concentration (10–100 mg dm−3), and the initial pH (pH = 4–9). The results showed that CR removal efficiency increased with the increase of biosorbent concentration and contact time. Increase of initial CR concentration led to an increase of the biosorption capacity, but also a decrease of CR removal efficiency. The highest CR removal efficiency was achieved at pH = 4, while at pH = 9 a significant decrease was noticed. The percentage of CR removal from synthetic wastewater was 18.6% higher than from model CR solution. The Langmuir model fitted well the biosorption data, with the maximum biosorption capacity of 8 mg g−1. The kinetics data were found to conform to the pseudo-second-order kinetics model.
Since the synthetic dye Congo red and nitrate are notorious contributors to water pollution due to their persistent and potentially toxic nature, it is necessary to develop new efficient methods to ...remove them from water bodies. Native lignocellulosic materials as biosorbents are mostly inferior, i.e., the adsorption capacities of native materials are lower. Therefore, attempts have been made to improve the adsorption capacities of such materials by physical and/or chemical methods, including the production of biochar. In this study, adsorptive removal was investigated using a novel biosorbent (mPWS) obtained by modifying poplar (waste) sawdust through quaternisation. The characterisation of mPWS included SEM/EDX, FTIR, and MIP analysis. The adsorption of CR and nitrate onto mPWS was studied in a batch system, as a function of contact time (1–240 min), biosorbent concentration (1–8 g·dm−3), and initial adsorbate concentration (25–200 mg·dm−3). In all experiments, a high removal of both adsorbates, from 60 to over 90%, was achieved. Langmuir and Freundlich adsorption isotherm models were used in order to describe equilibrium adsorption data, while pseudo-first-order and pseudo-second-order kinetic models, and the intraparticle diffusion model, were used to describe possible adsorption mechanisms. The Langmuir model fit the adsorption data of CR well, while the nitrate adsorption process was better interpreted with the Freundlich isotherm model. The kinetics data for both CR and nitrate agreed with the pseudo-second-order kinetics model, while analysis using the intraparticle diffusion model indicated two rate-limiting steps during the adsorption process. Based on the results, it can be concluded that the tested novel biosorbent can be effectively used for the removal of CR and nitrate from water (with its adsorption capacities being 70.3 mg·g−1 and 43.6 mg·g−1, respectively).
Contaminants of emerging concern (CECs) are chemicals or materials that are not under current regulation but there are increasing concerns about their possible occurrence in the environment because ...of their potential threat to human and environmental health, with wastewater perceived as their primary source. Although various techniques for their removal from water have been studied, it should be emphasized that the choice should also consider the use of resources and energy within the removal processes, which must be minimized to avoid additional carbon footprints and environmental impact. In this context, the use of biomass-based sorbents might represent a cost-effective and environmentally friendly approach for the removal of CECs from water because they are based on preferably local renewable resources with lower negative impacts on the global carbon cycle through greenhouse gas emissions than the conventional nonrenewable ones. This paper provides an overview of the studies dealing with the application of such so-called biosorbents for the removal of CECs from water and discusses the use of their different forms: sorbents after a minimal pretreatment of the original lignocellulosic biomass; sorbents extracted from lignocellulosic biomass and/or modified; and biochar-based sorbents obtained after thermochemical conversion of biomass. It explains possible modifications of biosorbents and discusses the efficiency of various biosorbents for the removal of selected emerging compounds that belong to the classes of pharmaceuticals, personal care products, and pesticides and compares the adsorption capacities, kinetic models, and mechanisms reported in the relevant literature. Biochar-based sorption has been studied more often if compared to other considered biosorbents. In some cases, removal efficiencies of contaminants greater than 90% were achieved, but nonetheless a wide range of efficiencies for different CECs indicates that for successful simultaneous multicompound removal, a combination of different processes seems to be a more appropriate approach than the stand-alone use of biosorbents. Finally, this review discusses the reasons behind the limited commercial application of the considered biosorbents and provides directions for possible further research, in particular the use of spent biosorbents from a perspective of circular systems.
Blackberry wine is a natural source of bioactive phenolic compounds that have profound antioxidant potential. The objectives of the present research were to assess the phenolic compounds and ...antioxidant activity of blackberry wines (BW), and to use the chemometric analysis to differentiate among the two groups of samples, i.e., conventional and organic. Fifteen BW samples were analyzed for their total polyphenol index, total polyphenols, total flavonoids, total tannins, total monomeric anthocyanins and antioxidant activity by the appropriate spectrophotometric methods. The concentrations of individual phenolic acids (gallic acid, chlorogenic acid, caffeic acid, p-coumaric acid and cinnamic acid) and trans-resveratrol were determined by high-performance liquid chromatography. A comparison between the two groups of investigated BW samples revealed a statistically significant difference in the concentration of caffeic acid and p-coumaric acid, both being higher in the organic BW samples. Furthermore, the results showed a series of statistically highly significant relationships between the analyzed constituents (caffeic acid and p-coumaric acid). The antioxidant activity of the investigated wines was proportional to the concentrations of bioactive phytochemicals.
One of the major challenges in sustainable waste management in the agri-food industry following the "zero waste" model is the application of the circular economy strategy, including the development ...of innovative waste utilization techniques. The conversion of agri-food waste into carriers for the immobilization of enzymes is one such technique. Replacing chemical catalysts with immobilized enzymes (i.e., immobilized/heterogeneous biocatalysts) could help reduce the energy efficiency and environmental sustainability problems of existing chemically catalysed processes. On the other hand, the economics of the process strongly depend on the price of the immobilized enzyme. The conversion of agricultural and food wastes into low-cost enzyme carriers could lead to the development of immobilized enzymes with desirable operating characteristics and subsequently lower the price of immobilized enzymes for use in biocatalytic production. In this context, this review provides insight into the possibilities of reusing food industry wastes, namely, eggshells, coffee grounds, and brown onion skins, as carriers for lipase immobilization.
Morphological and biochemical responses were assessed in an iceberg (GIL) and butterhead (GBL) lettuce (Lactuca sativa var. capitata) treated with commercially available soluble preparation of ...mycorrhizal fungi and beneficial soil bacteria (MT) grown in three irrigation treatments considered in greenhouse (continental Croatia, 2022): I100—control treatment (100% volumetric water content—VWC); I80—80% VWC, moderate drought and I60—60% VWC, severe drought), in two growing cycles. MT was applied during lettuce drought-sensitive stages, i.e., transplanting and heading. Study results show that MT improved lettuce growth-related traits, yet the results are genotype and growing-cycle dependent. The beneficial effect of MT was also noted for root length, weight, and diameter which confirms the mycorrhizal role in improving the plant water uptake. Both lettuce genotypes responded to water deficit by overproduction of MDA and proline content, whereby the response of tested variables was growing cycle and genotype-specific. Both genotypes in severe drought treatment (MT-I60) responded with higher MDA in the first growing cycle and lower MDA content in the second growing cycle. MT-I60 treatment reduced proline accumulation in GBH in both growing cycles, while increased accumulation in GIL during the second growing cycle. The responses of lettuce to MT are genotype-specific and shaped by environmental conditions.
In this study, commercially available traditional blackberry products, namely blackberry wines and blackberry elixirs from Coastal Croatia and Bosnia and Herzegovina, were investigated as sources of ...bioactive compounds, essential nutrients and metals. Samples were analysed for pH, total polyphenols and monomeric anthocyanins content, individual phenolic acids (gallic acid, chlorogenic acid, caffeic acid and p-coumaric acid), antioxidant activity (DPPH and ABTS), reducing power (RPA), total nitrogen and phosphorus as well as metals (K, Na, Ca, Mg, Fe, Mn, Cu, Zn, Co, Cr, Cd). The results of this study showed that the studied traditional blackberry products are rich sources of polyphenols and their consumption could increase the daily intake of dietary antioxidants in humans. In addition, both groups of traditional blackberry products could be considered safe for health and good additional sources of essential minerals such as manganese and potassium. The concentrations of the analysed undesirable toxic and potentially toxic metals in the studied blackberry products were below the maximum allowable concentrations defined by various regulations for wines and fruit wines.
Background and Purpose: Wood and wood processing industries are generators of a substantial amount of waste wood biomass, such as wood chips, shavings and sawdust. Such waste is often unused and its ...disposal can be a serious environmental problem. Different lignocellulosic waste materials have been successfully used as low-cost adsorbents (biosorbents) for the removal of synthetic dyes, as well as other contaminants, from wastewater. The aim of this study was to valorise the waste wood biomass of ten tree species, out of which seven are the most represented species of the Croatian growing stock, as biosorbents for the removal of synthetic dye methylene blue (MB) from model solutions.
Materials and Methods: The waste wood biomasses (shavings or sawdust) of ten tree species, namely common beech, pedunculate oak, sessile oak, common hornbeam, narrow-leafed ash, poplar, European silver fir, Norway spruce, European larch and Douglas fir, were dried and milled prior to characterisation and adsorption experiments. Characterisation of the biosorbents was performed by chemical analysis and Fourier transform Fourier transform infrared spectroscopy (FTIR). Upon characterisation, batch adsorption experiments were conducted in order to survey waste wood biomass as potential adsorbents for the removal of synthetic dye MB. The colour removal was monitored spectrophotometrically at predetermined time intervals. Further adsorption experiments were performed using poplar sawdust. The effects of contact time, biosorbent concentration, initial dye concentration, and pH on the adsorption process were investigated. The experimental data obtained by batch adsorption experiments were analysed using adsorption isotherm models (Freundlich and Langmuir).
Results: All the tested biosorbents were found to be very effective for the removal of MB from model dye solution, achieving high removal percentages ranging from 93.25 to 98.50%. Poplar sawdust proved to be the most effective. It was shown that MB adsorption process onto poplar sawdust could be interpreted in terms of Langmuir and Freundlich adsorption isotherm models.
Conclusions: Taken together, these results suggest that waste wood biomass has the potential to be used as a low-cost biosorbent for MB removal from aqueous solutions.
The occurrence of arsenic in natural ground waters is due to geological composition of soil. There are several methods for removal of arsenic from drinking water, such as coagulation followed by ...filtration, membrane processes, ion exchange and adsorption. Adsorption methods proved to be effective, economic, easy to perform and construct. The objective of this study was to investigate the removal of arsenic from drinking water using adsorbents prepared by coating the surface of the following polymeric materials: natural alum silicate exchanger zeolite clinoptilolite and ionic exchanger Dowex Marathon C with hydrous ferric oxide. Modified adsorbents were saturated with Fe
3+ ions from the FeCl
3 solution in acetate buffer solution (pH 3.6) and then converted to hydrous ferric oxide by thermo chemical procedure (NaOH, NaCl, 50°C). Adsorption kinetics of arsenic was investigated as a function of initial arsenite and arsenate concentrations (ranging from 100 to 500 μg/L), contact time (from 15 to 360 min) and pH (6.4, 6.9, 7.4, 7.9). The results and sorption characteristics of the prepared hydrous ferric oxide/polymeric material adsorbents were determined using Freundlich and Langmuir adsorption isotherms.
The presence of heavy metals in an agricultural land is the primary cause of food product toxicity of a herbal and animal origin associated with a contaminated agricultural land. The anthropogenic ...sources of pollution, especially the fertilizers and pesticides in agriculture, are the primary sources of agricultural land contamination with heavy metals. The heavy metals whose monitoring is prescribed by the current legislation of the Republic of Croatia include cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb) and zinc (Zn). The aim of this paper is to provide a review of heavy metals that cause contamination of an agricultural land, as well as a review of remediation technologies applied to reduce contamination. Furthermore, the paper considers three groups of remediation technologies, i.e., the biological, chemical, and physical ones, analyzing the applicability, efficiency, cost-effectiveness and accessibility in Croatia to encourage their wider implementation. The biological remediation technologies, also known as phytoremediation, met the set criteria the most, which currently renders them most applicable to the mildly‐ and moderately‐contaminated agricultural land. The chemical and physical remediation technologies are generally more suitable for the remediation of a severely contaminated agricultural land, applied individually or in combination with the phytoremediation methods due to the high cost.
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