Cong-red dye is a precursor of various products of cotton industry and its toxicity in the aquatic environment is a great concern. Present study was highlighted on the efficacy of the fish scale char (FSC) towards removal of congo red from aqueous solution. The prepared FSC was characterized by zero point charge (pHZPC), scanning electron micrograph with elemental analysis (SEM-EDX) and fourier transform infrared (FTIR). Based in the equilibrium and kinetic study, the Langmuir (R2 = 0.967) and Pseudo-second-order (R2 = 1.00) models are appropriate to describe the dye adsorption process. The randomness and exothermic nature of the system were confirmed by the negative values of both entropy and enthalpy, respectively. Finally, optimization by Response Surface Methodology (RSM) study revealed that the experimental data were nicely fitted with central composite design with very high F value (F = 1596.24, p < 0.0001). Perturbation plot suggested that congo-red dye removal is more sensitive with respect to biosorbent dose, pH and initial concentration. The exhausted adsorbent was regenerated with 0.5(M) NaOH solution. Therefore, it can be concluded that fish scale char could be a valuable materials towards purification of industrial effluent.

Elevated level of fluoride (> 1.0 mg/L) in drinking water leads to both dental and skeletal fluorides. Present research is dedicated to check the efficacy of duck shell dust towards removal of fluoride. Various analytical tools (XRF, XRD, SEM-EDAX and zero point charge) were used to characterize the present adsorbent. The entire batch mode study results were further optimized by Response Surface Methodology (RSM). The results revealed that Langmuire isotherm is best fitted (R2 = 0.819) with adsorption capacity 4.894 mg/g. However, kinetic study suggest that the fluoride adsorption followed pseudo-second-order kinetic equation (R2 = 0.956). Similarly, thermodynamic study revealed that the fluoride adsorption by duck shell dust is endothermic and entropy driven process. Finally, optimization study demonstrated the optimized condition such as initial concentration, adsorbent dose, contact time and pH are 89.29 mg/L, 1.112 g/100 mL, 42.5 min and 9.91, respectively. Therefore, it may be concluded that duck shell dust could be a promising adsorbent for decontamination of fluoride from contaminated body.

Major part of implemented measures was aimed at early artificial forest regeneration and securing plantations, or protection of young forest stands against damage by bark beetles. Only exceptionally there were proposed measures with the aim to increase vitality, stability and improvement of the structure of forest stands by their tending. It was worked out a draft of procedures for forest managers to help them in deciding at which stocking it is necessary to reforest reduced or actual clearings, whether to fell down open stands or to leave them regarding their age, state and expected further development

The attention was focused on the diameter increment of beech timber forest growing on the partial plots with various stand density. The individual parts of the originally homogenous stand, were subjected to regeneration cutting of various intensity resulting in several partial plots. On the different partial plots we found different proportions of trees belonging to the individual diameter classes. We also found that the differences between the individual plots were statistically very significant. Beech is a tree species which is capable to continue creating considerable light increments even long after the stand opening

The main aims of the preparatory stands in air pollution areas are growth development, successfull dynamics of the plants and fast creation of the stand microclimate with favourable effect on soil conditions. This process is documented by height and diameter increment. The results confirm different growth dynamics of the particular species. Larch is the species with the best growth dynamics of selected species on experimental plots. On the other hand, beech is the worst species for reforestation in this condition. One of the causes could be damage by frost

The paper presents forest damage in Saxony, silvicultural treatment and the choice of tree species, base of the choice of tree species for areas damaged by air pollutants and solving the problems only on interdisciplinary basis

Spis region is due to long-term effect of air pollution one of the most polluted regions in Slovakia. Decline of trees, mostly of spruce, was recorded here altogether with disintegration of forest stands. Incidental felling and its volume is frequently connected with local source of air pollution from iron-ore works Rudnany and Kovohuty. Long-range transfer of air pollutants from Poland (Katowice) plays a certain role in air pollution as well. In the year 1994 the damaged stands were classified into the zones of endangerment, the period of the validity of forest management plan was shortened and there were proposed measures for forest regeneration

The presence of higher concentrations of heavy metals in water affects its quality with a concomitant adverse effect on its users thus their removal is paramount. A novel adsorbent, PN-Fe₃O₄-IDA derived from the chemical modification of peanut husk (a low-cost agricultural biomass produced in significant quantities globally) using magnetic nanoparticles (Fe₃O₄) and iminodiacetic acid was utilized for the remediation of heavy metals in aqueous solution. Analytical techniques vis-à-vis the Fourier-Transform Infrared, Scanning Electron Microscope, Brunauer–Emmett–Teller, X-ray photoelectron spectroscopy and X-ray Diffraction were applied for the characterization of PN-Fe₃O₄-IDA. Results from the characterization studies showed that PN-Fe₃O₄-IDA possessed a mesoporous structure, a heterogeneous surface and functional groups such as carboxylic acid and a tertiary nitrogen atom which enhanced its adsorption capacities as well as magnetic properties which ensured its easy removal from the solution using a magnet. The maximum uptake of Pb and Cu onto PN-Fe₃O₄-IDA was 0.36 and 0.75 mmol g⁻¹ (at 318 K) respectively with the chemisorption process being the major reaction pathway for the processes. The synthesized adsorbent exhibits significant adsorption capacity for the selected pollutants as well as some unique features which promotes its use as an adsorbent for wastewater remediation processes.

Sediment dredging is considered an effective restoration method to reduce internal loading of nitrogen (N) and phosphorus (P) in eutrophic lakes. However, the effect of dredging on N release from sediments to overlying water is not well understood. In this study, N exchange and regeneration across the sediment-water interface (SWI) were investigated based on a one-year simulated dredging study in Lake Taihu, China. The results showed low concentrations of inorganic N in pore water with low mobilization from the sediments after dredging. The calculated fluxes of NO3−-N from post-dredged sediments to overlying water significantly increased by 58% (p < 0.01), while those of NH4+-N dramatically decreased by 78.2% after dredging (p < 0.01). N fractionation tests demonstrated that the contents and lability of N generally declined in post-dredged sediments. Further high-throughput sequencing analysis indicated that relative abundance of the bacterial communities decreased, notably by 30% (compared with undredged sediments). The estimated abundance of Nitrospira enhanced, although the relative abundance of Thiobacillus, Sterolibacterium, Denitratisoma, Hyphomicrobium, Anaeromyxobacter and Caldithrix generally declined after dredging. Therefore, dredging reduced N mobilization from the sediments, which primarily due to decreases in N mobility, in organic matter (OM) mineralization potential and in the bacterial abundance of post-dredged sediments. Overall, to minimize internal N pollution, dredging is capable of effectively reducing N release from sediments. In addition, the negative side effect of dredging on removal of NO3−-N and NO2−-N from aquatic ecosystems should be paid much more attention in future.