The polysaccharidic moieties of three biosorbents (Douglas fir and argan tree barks and argan endocarp) were selectively oxidized, and the subsequent modified materials were tested for their ability to bind Pb(II) or Cd(II) from aqueous solutions. Chemical modifications consisted in two selective oxidations, alone or in combination, of the following groups: primary alcohols with NaOBr catalyzed by (2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl, and vicinal diols with periodate/chlorite. The sodium chlorite oxidation step induced biosorbent degradation that led to a significant decrease of mass yield. Modified materials, characterized by FT-IR spectroscopy and measurement of surface acidity, were investigated for their adsorption capabilities of Cd(II) and Pb(II). Results were compared to the capabilities of crude materials using the Langmuir adsorption model in terms of affinity (b) and maximum binding capacity (q ₘₐₓ). Ion exchange properties were found better for lead than for cadmium before and after chemical modifications. Compared to crude barks, the best results were obtained for Douglas fir barks whose oxidation resulted in significant enhancements of q ₘₐₓ up to × 10 in the case of lead.

Reaeration coefficient (k), the rate of oxygen exchange between the atmosphere and water surface, is an important parameter for understanding water quality impairment and stream metabolism. We modified the propane injection method to measure gas exchange coefficients and evaluated its application for small streams. The tracer solution was prepared by solubilizing propane directly in a conservative solute solution, and it was injected as a constant-rate injection, a single slug, or an extended slug. Water samples were taken at four to five sampling stations along the study reach at the tracer concentration peak, and propane and conductivity were measured. The propane exchange rate (k ₚᵣₒₚₐₙₑ) was calculated using the regression method with the propane/conductivity ratio against solute travel time (in hours). The mixed tracer injection method was conducted in four streams, and all k ₚᵣₒₚₐₙₑ measurements (n = 8) were statistically significant (p < 0.05). The short-duration constant rate injection and extended slug injection provided k ₚᵣₒₚₐₙₑ estimates with higher r ² than the single slug injection. The k ₂₀ measured with propane injection ranged from 5.4 to 40.0 day⁻¹, and they were significantly correlated with empirically estimated k. The mixed tracer injection method with propane could potentially reduce field time, crew demands, and field equipment; thus, it would potentially lower the overall cost of gas exchange coefficient measurements and be an effective method in small, remote streams.

A series of aluminum oxyhydroxide-incorporated titania composites were prepared by a one-pot synthetic procedure using aluminum tri-sec-butoxide as a precursor. The as-synthesized samples were characterized by Fourier transform infrared spectrophotometer, X-ray diffraction, thermogravimetry and differential scanning calorimetry, nitrogen physisorption, and scanning electron microscopy. It was identified that aluminum oxyhydroxide (γ-AlOOH, or boehmite) was produced as aluminum matrix into which titania, commercially available P25, was incorporated. Photocatalytic activity of all nanocomposites was evaluated with respect to the photodecolorization of methyl orange under UV irradiation and almost complete decolorization was eventually achieved under optimum experimental conditions.

Alberta’s oil sands are located in the boreal forest where surface mining requires reconstruction of these landscapes using waste saline and sodic overburden (SSOB) piles. The impact of these SSOB materials, however, on root development of planted boreal species is unknown. The objective of this study was to examine the effect of SSOB material on the root distributions of planted boreal species. Root distributions for planted mixedwood stands were measured using soil cores and compared with soil physical and chemical properties on three reclaimed sites. Soil pH ranged from 6.1 to 7.5 across all three reclaimed sites. Sodium adsorption ratio ranged from <30 in the SSOB at the youngest site to <4 at the oldest site while soil electrical conductivity ranged from <12 and <4 dS m−1 in the SSOB at the youngest and oldest site, respectively. Root length distributions were concentrated in the upper 30 cm of the soil profile and ranged from 0.96 to 7.99 cm cm−3. The roots were observed in the SSOB and accounted for 1.3% to 2.2% of the total root length in the profile. The root length density was also negatively correlated with Na and EC at all sites. The root distributions on these young reclaimed sites were similar to those from undisturbed boreal forest stands overlying saline soils, suggesting that root distributions on these reclaimed sites appear to be unaffected by the SSOB; however, further monitoring will be required as the stand matures to determine future impacts of the SSOB on forest productivity.

Filamentous fungi derived from marine environments are well known as a potential genetic resource for various biotechnological applications. Although terrestrial fungi have been reported to be highly efficient in the remediation of xenobiotic pollutants, fungi isolated from the marine environment may possess biological advantages over terrestrial fungi because of their adaptations to high salinity and pH extremes. The present study describes the production of ligninolytic enzymes under saline and non-saline conditions and the decolorization of Remazol Brilliant Blue R (RBBR) dye by three basidiomycetes recovered from marine sponges (Tinctoporellus sp. CBMAI 1061, Marasmiellus sp. CBMAI 1062, and Peniophora sp. CBMAI 1063). Ligninolytic enzymes were primarily produced by these fungi in a salt-free malt extract and malt extract formulated with artificial seawater (saline condition). CuSO₄ and wheat bran were the best inducers of lignin peroxidase and manganese peroxidase activity. RBBR was decolorized up to 100% by the three fungi, and Tinctoporellus sp. CBMAI 1061 was the most efficient. Our results revealed the biotechnological potential of marine-derived basidiomycetes for dye decolorization and the treatment of colored effluent as well as for the degradation of other organopollutants by ligninolytic enzymes in non-saline and saline conditions that resemble the marine environment.

Increasing environmental pollution is connected with broad applications of dyes and imperfection of dyeing technology. Decolourization of triphenylmethane brilliant green and disazo Evans blue by bacterial and fungal strains and toxicity (phyto- and zootoxicity) of degradation by-products were investigated. Influence of incubation method on dyes removal was evaluated (static, semi-static, shaken). Dead biomass was used for sorption estimation. Toxicity of treated dyes was measured to estimate possible influence on aquatic ecosystems. The zootoxicity test was done with Daphnia magna and phytotoxicity with Lemna minor. Samples were classified according to ACE 89/BE 2/D3 Final Report Commission EC. The best results of removal for all tested strains were reached in shaken samples. In opposite to fungi, bacterial strains decolourized brilliant green more effectively than Evans blue. The most effective bacterial strain was Erwinia spp. (s12) and fungal strains were Polyporus picipes (RWP17) and Pleurotus ostreatus (BWPH and MB). Decolourization of brilliant green was connected with decrease of zootoxicity (D. magna) and phytotoxicity (L. minor). Removal of Evans blue was connected with no changes in zootoxicity and decrease of phytotoxicity in most of samples.

Water quality of Lake Okeechobee has been a major environmental concern for many years. Transport of dissolved organic matter (DOM) in runoff water from watershed is critical to the increased inputs of nutrients (N and P) and metals (Cu and Zn). In this study, 124 soil samples were collected with varying soil types, land uses, and soil depths in Lake Okeechobee watershed and analyzed for water-extractable C, N, P, and metals to examine the relationship between dissolved organic carbon (DOC) and water soluble nutrients (N and P) and metals in the soils. DOC in the soils was in 27.64–400 mg kg⁻¹ (69.30 mg kg⁻¹ in average) and varied with soil types, land uses, and soil depth. The highest water-extractable DOC was found in soils collected in sugar cane and field crops (277 and 244 mg kg⁻¹ in average, respectively). Water soluble concentrations of N and P were in the range of 6.46–129 and 0.02–60.79 mg kg⁻¹, respectively. The ratios of water-extractable C/N and C/P in soils were in 0.68–12.52 (3.23 in average) and 3.19–2,329 (216 in average), and varied with land uses. The lowest water-extractable C/N was observed in the soils from dairy (1.66), resident (1.79), and coniferous forest (4.49), whereas the lowest water-extractable C/P was with the land uses of dairy (13.1) and citrus (33.7). Therefore, N and P in the soils under these land uses may have high availability and leaching potential. The concentrations of water soluble Co, Cr, Cu, Ni, and Zn were in the ranges of < method detection limit (MDL)–0.33, <MDL–0.53, 0.04–2.42, <MDL–0.71, and 0.09–1.13 mg kg⁻¹, with corresponding mean values of 0.02, 0.01, 0.50, 0.07, and 0.37 mg kg⁻¹, respectively. The highest water soluble Co (0.10 mg kg⁻¹), Cr (0.26 mg kg⁻¹), Ni (0.31 mg kg⁻¹), and Zn (0.80 mg kg⁻¹) were observed in soils under the land use of sugar cane, whereas the highest Cu (1.50 mg kg⁻¹) was with field crop. The concentration of DOC was positively correlated with total organic carbon (TOC) (P <0.01), water soluble N (P <0.01), electrical conductivity (EC, P <0.01), and water soluble Co, Cr, Ni, and Zn (P <0.01), and Cu (P <0.05), whereas water soluble N was positively correlated with water soluble P, Cu, and Zn (P <0.01) in soils. These results indicate that the transport of DOC from land to water bodies may correlate with the loss of macro-nutrients (N, P), micro-nutrients (Cu, Zn, and Ni), and contaminants (Cr and Co) as well.

In remotely located watersheds or large waterbodies, monitoring water quality parameters is often not feasible because of high costs and site inaccessibility. A cost-effective remote sensing-based methodology was developed to predict water quality parameters over a large and logistically difficult area. Landsat spectral data were used as a proxy, and a neural network model was developed to quantify water quality parameters, namely chlorophyll-a, turbidity, and phosphorus before and after ecosystem restoration and during the wet and dry seasons. The results demonstrate that the developed neural network model provided an excellent relationship between the observed and simulated water quality parameters. These correlated for a specific region in the greater Florida Everglades at R ² > 0.95 in 1998–1999 and in 2009–2010 (dry and wet seasons). Moreover, the root mean square error values for phosphorus, turbidity, and chlorophyll-a were below 0.03 mg L⁻¹, 0.5 NTU, and 0.17 mg m⁻³, respectively, at the neural network training and validation phases. Using the developed methodology, the trends for temporal and spatial dynamics of the selected water quality parameters were investigated. In addition, the amounts of phosphorus and chlorophyll-a stored in the water column were calculated demonstrating the usefulness of this methodology to predict water quality parameters in complex ecosystems.

Slaughterhouse waste water (SHW) is discarded as unused disposals into the environment every day. The objective of the present study is to explore the possibility on the utilization of SHW for the preparation of culture media to produce mosquitocidal bacterium (Bacillus thuringiensis subsp. israelensis). This would help to overcome the problem of dumping SHW in to environment. A judicial combination of SHW with a mineral salt (MnCl2) was made to produce an enhanced level of bacterial production when compared with other culture media including conventional medium (Luria Bertani, LB). A complete degradation of SHW by the bacteria was observed. The biomass yield, bacterial growth, toxin production, and larvicidal activity against mosquito vectors were satisfactory. Cell mass yield of 4.55 gm l−1 (dry wt) and larvicidal activity of 0.006 mg ml−1 and 0.026 mg ml−1 at LC50 and LC90 levels were observed, respectively, against the filarial vector of Culex quinquefasciatus with bacteria grown in SHW + MnCl2. The B. thuringiensis subsp. israelensis also controlled the larvae in the field significantly for three weeks (>90% mortality) and the effect was comparable with LB. Cost-analysis for production of B. thuringiensis subsp. israelensis showed that it is more economical. Thus, this study suggested the dual benefit of efficient production of mosquitocidal toxin and management of slaughterhouse wastewater.

We performed a 2-year microcosm study to assess the effectiveness of red mud, a by-product of bauxite processing, in stabilizing contaminated mine waste and agricultural soil. Our study used red mud from a long-term disposal area in Almásfüzitő, Hungary with a pH of 9.0. A 5% (by weight) red mud addition decreased the highly mobile, water-extractable amount of Cd and Zn by 57% and 87%, respectively, in the agricultural soil and by 73% and 79%, respectively, in the mine waste. In a laboratory lysimeter study, the addition of red mud reduced the concentration of Cd and Zn in the leachate by about two third of the original. The metal content of the leachate was below the Maximum Effect Based Quality Criteria for surface water as determined by a risk assessment in the metal-contaminated area of the Toka valley near Gyöngyösoroszi, Hungary. The addition of red mud did not increase the toxicity of the treated mine waste and soil and decreased the Cd and Zn uptake of Sinapis alba test plants by 18–29%. These results indicate that red mud applied to agricultural soil has no negative effects on plants and soil microbes and decreases the amounts of mobile metals, thus indicating its value for soil remediation.