This study was performed to evaluate the ability of white-rot fungi to decolorize dye effluents. A total of 222 isolates of white-rot fungi were initially investigated to assess their ability to decolorize chemically different synthetic dyes in solid medium, resulting in selection of 25 isolates including four isolates of Berkandera adusta, five isolates of Ceriporia lacerata, three isolates of Irpex lacteus, one isolate of Perenniporia fraxinea, ten isolates of Phanerochaete spp., one isolate of Phlebia radiata, and one isolate of Porostereum spadiceum. Of the 25 isolates, B. adusta KUC9065, C. lacerata KUC8090, P. calotricha KUC8003, and P. spadiceum KUC8602 were finally selected on the basis of their ability to decolorize synthetic dyes in liquid medium, and were used to decolorize industrial effluents. B. adusta KUC9065 increased the transmittance of visible light by 71–92 %. Decolorization of wastewater by B. adusta KUC9065 was probably caused by the lignin-modifying enzymes produced by the fungus. In addition, the acute toxicity to Daphnia magna decreased from 2.5 to 2.1 and from 3.5 to 2.6 toxic units over 24 and 48 h, respectively.

Clay minerals have been utilized for the remediation of heavy metal-polluted soil. However, information on the remediation stability of various clay minerals with different performances is limited. In this study, a kind of palygorskite (PAL) with a sorption amount for Cd²⁺about 40 mg/g, which is much larger than common minerals, was selected as amendment for in situ immobilization field demonstration. Besides, sorption stability which is essential for remediation was investigated in an ideal solid solution system by sorption and desorption behaviors of Cd²⁺on PAL, including isotherms, kinetics, and various stimulated environmental factors such as pH, temperature, and background electrolytes. The calculated thermodynamic parameters confirmed the sorption process was endothermic and driven by entropy changes. Only minimal desorption was caused by stimulated irrigation or runoff and acid rain. The temperature, pH, and background electrolyte dependence confirmed that the sorption of Cd²⁺on PAL was stable. Various characterization results including X-ray photoelectron spectroscopy (XPS), scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) mapping, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) confirmed the sorption mechanisms were surface precipitation of CdCO₃and surface complexation with hydroxyl groups.

Bauxsol is a chemico-physically modified product of red mud and is a promising material for the removal and recovery of phosphorus from wastewater. In this study, response surface methodology (RSM) and artificial neural network (ANN) were employed to develop prediction models and also to investigate the interactions of independent experimental factors for phosphorus adsorption onto acid-activated Bauxsol. The experimental results indicated that HCl activation was effective to improve the adsorption capacity of Bauxsol. The maximum adsorption capacity of acid-activated Bauxsol was 55.72 mg/g (as P) with HCl concentration of 10.20 mol/L, temperature of 41.00 °C, and time of 5.60 h, which increased by 10.53 and 6.62 times compared with the raw red mud and Bauxsol before acid activation, respectively. The relative importance of HCl concentration in RSM and ANN models was 51.78 and 54.25 %, respectively, which illustrated that HCl concentration played the predominant role on improving the adsorption capacity of Bauxsol. The predictive capability of RSM and ANN models was compared, and the results showed that both models provided excellent predictions with R² > 0.93. However, the ANN model showed the superiority over RSM for estimation capability.

Sorption–desorption behavior of the antibiotic tetracycline (TET) and the synthetic estrogen hormone 17α-ethinylestradiol (EE2) with wastewater sludge and sludge-derived humic substances [humic acid (HA) and humin] was investigated. From acidic functional group capacity and elemental analyses, HA had higher polarity, aromaticity, and acidity than humin; humin contained aliphatic chains with high mineral content. The different physicochemical properties of the pharmaceuticals and sludge components yielded different kinds of sorption–desorption interactions. Partitioning coefficients (Kd) of TET to sludge were higher (1,552 ± 41–4,667 ± 41 L/kg) than EE2 (534 ± 52–609 ± 47 L/kg). TET sorption was highly pH-dependent and maximal at pH 9. Ca²⁺ions enhanced sorption, emphasizing the role of polyvalent metal ions in forming TET–sludge complexes. Humin was the dominant component for TET sorption due to its high inorganic matter content. In contrast, EE2 sorption was independent of solution pH, forming mostly hydrophobic interactions with sludge organic matter. EE2 had a high affinity for HA due to its chemical structure. Desorption of the two pharmaceuticals differed as well. The amount of desorbed TET (18.7 ± 1.3–29.8 ± 2 %) was lower than that of EE2 (60.6 ± 3–62.3 ± 2 %), and the hysteresis index was higher for TET than EE2. While TET desorption tended to be delayed in the solid matrix, EE2 desorbed easily and in accordance with the aqueous equilibrium concentration. The conclusions emphasize the need for further research into frequently used pharmaceuticals with different physicochemical properties and the recognition of sludge application as an important source of distribution for these contaminants in the environment.

This paper reports about the modification of sand and fumed silica with titania in order to obtain a photocatalytic active material for the degradation of pollutants. The coating process was performed based on the sol–gel method. Tetrapropylorthotitanate was used as the titania precursor to apply a nanoscaled layer on sand grains. For silica fume, the coating process was varied. Various amounts of tetrapropylorthotitanate were used to obtain different coating thicknesses and to identify the maximum amount of titania that could be loaded on the material. All samples showed high photonic efficiencies in the degradation of nitrogen monoxide despite their low titania quantities, which were identified via x-ray fluorescence analysis. Some samples showed higher photonic efficiencies than commercial Degussa P25. Due to the preparation method, calcination of the sand composites was not necessary to yield a crystalline coating which was responsible for the high photocatalytic activity. However, silica fume composites had to be calcined possibly due to variation in the preparation method. Scanning electron micrographs revealed the structured morphology of all specimens. Energy dispersive x-ray analysis identified nanoscaled titania particles on the sand surface that could not be observed only via SEM. The results of this research are especially interesting for large scale applications of photocatalysts. As industrial sand and silica fume used are low cost materials, this new kind of photocatalyst can be applied in higher quantities and distributed onto larger areas, while saving costs at the same time.

Stressed communities show changes in energetics and nutrient demand and recovery. The evaluation of microbial communities energy demand can be measured by enzyme activities. Thus, by using such approaches, it might be possible to determine the microbial response to metal contaminations. Guanabara Bay surface sediments were sampled in 20 stations. Grain size, bioavailable metals, total organic carbon, total sulfur, dehydrogenase activity, esterase activities, viable bacterial cells, carbohydrates, lipids, and proteins were determined in all samples. Bioavailable metal concentration ranges from below detection limit in sandy stations in the entrance of the bay by up to the same order of magnitude as total concentrations obtained by other authors. Biopolymers were mainly lipids and carbohydrates, and minimum concentrations were also observed in sandy sediments. C:S ratio of 4.4 ± 1.3 (mean ± standard deviation) expresses the reduced tendency conditions of the bay, negatively correlated to viable bacteria cells (in order of 10⁷ cell g⁻¹). Esterase enzyme activities positively correlated with organic and fine sediment content. Stations with the highest metals and organic contents also have the highest esterase activities and dramatic decline of bacterial cells. In these locations occur better water renewal and subsequent aeration, which increases the efficiency of the organic matter oxidation and decreases matrix geochemical sequestration of metals and renders them bioavailable.

The aim of the present study was the decolourisation of mixture of two dyes belonging to different groups by two Pseudomonas fluorescens strains (Sz6 and SDz3). Influence of different incubation conditions on decolourisation effectiveness was evaluated. Dyes used in the experiment were diazo Evans blue (EB) and triphenylmethane brilliant green (BG). Another goal of the experiment was the estimation of toxicity of process by-products. Incubation conditions had a significant influence on the rate of decolourisation. The best results were reached in shaken and semistatic samples (exception Evans blue). After 24 h of experiment in semistatic conditions, BG removal reached up to 95.4 %, EB 72.8 % and dyes mixture 88.9 %. After 120 h, all tested dyes were completely removed. In most cases, dyes were removed faster and better by strain Sz6 than SDz3. At the end of the experiment, in majority of the samples, decrease of phyto- and zootoxicity was observed.

The effect of anaerobic digestion (AD), coarse solids removal, and a manure additive More Than Manureᵀᴹ (MTMᵀᴹ) on ammonia (NH₃) emission from raw (Non AD) dairy manure and AD manure was studied during 110 days of storage. The study consisted of eight treatments in duplicate: AD manure and non AD manure, with and without coarse solids, and with and without MTMᵀᴹ additive. These studies were conducted in a naturally ventilated barn. The nitrogen content of manure, especially the ammoniacal nitrogen, played an important role in NH₃ emission. During the first 11 weeks of the storage, AD manure had significantly greater peak (33 to 38 ppm) concentrations of NH₃, and NH₃ fluxes (94 to 130 μg min⁻¹ m⁻²) compared to raw manure (14 to 25 ppm and 55 to 81 μg min⁻¹ m⁻², respectively). From the 11th week until the end of storage, there was no significant difference in NH₃ emissions across the manure treatments. The presence of course solids resulted in significanlty less peak NH₃ for non AD manure when data were evaluated for the whole storage period. The manure additive MTMᵀᴹ did not have a significant effect on NH₃ emissions during storage, however, temperature was positively related to NH₃ emissions. Total ammoniacal nitrogen and solids concentration in manure was the most important factors affecting NH₃ emissions during storage.

Many of municipal wastewater treatment plants (WWTPs) are operated by biological process with their excellent performances. However, the early warning system in the influent line is required to avoid the process malfunction because the biological wastewater treatment system has serious drawback to toxic chemicals in the influent. In order to develop a new type of biosensor using anaerobic granules in an online device for rapid detection of toxic inhibitory to the biological process, a porous pot reactor and an anaerobic granule biosensor (AGB) were demonstrated as an upset early warning device (UEWD) in this study. In the first group of toxic loading tests, the prepared cupric chloride solutions were separately injected into both the porous pot and AGB systems at six different concentrations, and phenol solutions were used at three different concentrations in the second group of tests. The results showed the chemical oxygen demand (COD) and ammonia nitrogen (ammonia-N) removal efficiency from porous pot reactor decreased dramatically in response to the addition of Cu²⁺and phenol with the variation of the oxidation-reduction potential (ORP) in AGB. The response of AGB system was 6 to 20 h in advance of porous pot reactor performance response, which suggests that the AGB could potentially be used as an online UEWD.

A novel method of acid orange 7 (AO7) removal has been developed via the deposition of plasma-polymerized allylamine (ppAA) films on quartz particles. ppAA films were deposited at a power of 25 W, allylamine flow rate of 4.4 sccm and polymerization time of 5 to 60 min. Polymerization time had a significant effect on surface chemistry where the XPS nitrogen concentration, XPS C-O, C-N concentration, isoelectric point and the number of positively charged groups per nm²all increased with increasing polymerization time. Increasing polymerization time increased AO7 adsorption due to greater concentrations of positively charged amine groups on the surface. The pH and initial AO7 concentration were varied to investigate their effect on AO7 adsorption. Increasing the initial AO7 concentration increased adsorption for all polymerization times. pH had a significant effect on AO7 adsorption with maximum adsorption at pH 3 and significantly less at pH values of 5–9. Regeneration of ppAA-coated quartz particles for up to 4 cycles using pH 12 Milli-Q water resulted in only slight losses in adsorption capacities. ppAA-coated particles have shown to successfully remove AO7 dye from solution and therefore demonstrate potential for use in the treatment of industrial dye wastestreams.