This study investigates removal of total nitrogen (TN) in moving bed biofilm reactor (MBBR) supported with high-density polyethylene for biofilm formation and ibuprofen (IBU) as a carbon source. At first, the microorganisms have been acclimated for 45 days. In the optimum condition, TN removal of more than 80 % was reached. Optimization results of simultaneous removal of IBU and TN showed that the obtained removal efficiencies for IBU and TN are close together and the correlation coefficients have high values. The obtained results show that MBBR bioreactor could remove 72.03 % IBU and 81.1 % TN at 145.15 h and TN concentration of 156.37 mg/L. Biodegradation constant (k bᵢₒₗ) values were varying from 0.4 to 0.009 L/g biomass.d, which represents that IBU is a hard biodegradable or persistent substance. This study demonstrated that the proposed MBBR is highly effective for the simultaneous removal of IBU and TN in wastewater.

Due to their metal removal ability, bacterial biosorbents can be effectively used for the treatment of wastewaters containing heavy metals. Searching for bacterial biosorbents for hazardous heavy metals like cadmium is a pivotal for remediation efforts. The gene cadA, that mediates resistance to cadmium over an ATP-dependent efflux mechanism, provides a good target for the selection of potential cadmium biosorbents. For this reason, in this study, a 36-mer-oligonucleotide DNA probe based on the entire 3.5-kb BglII-XbaI fragment of cadA operon from staphylococcal plasmid pI258 was prepared by using Vector NTI Express software. Under the hybridization conditions of 46 °C, 50 % formamide, and 0.028 M NaCl, the designed cadA probe appeared to be highly specific to the cadA-positive Staphylococcus warneri and Delftia acidovorans isolates tested. The results indicated that the newly designed cadA-targeted DNA probe has potential as a specific, sensitive, and quantitative tool in selecting and in situ screening of potential cadmium biosorbents.

Phosphorus (P) associated with minerogenic particles delivered from watersheds can interfere with the common use of total P (TP) concentration as a trophic state metric in lacustrine systems, particularly proximate to tributary entries, because of its limited bioavailability. The concentration of unavailable minerogenic particulate P (PPₘ/ᵤ), where it is noteworthy, should be subtracted from TP in considering primary production potential and trophic state levels. A first mass balance model for PPₘ/ᵤ is developed and tested here for Cayuga Lake, New York. This is supported by a rare combination of detailed information for minerogenic particle level dynamics for the tributaries and lake, the bioavailability of tributary particulate P (PP), and previously tested hydrothermal/transport and minerogenic particle concentration submodels. The central roles of major runoff events and localized tributary loading at one end of the lake in driving patterns of PPₘ/ᵤ in time and space are well simulated, including (1) the higher PPₘ/ᵤ concentrations in a shallow area (“shelf”) adjoining the inputs, relative to pelagic waters, following runoff events, and (2) the positive dependence of the shelf increases on the magnitude of the event. The PPₘ/ᵤ component of P was largely responsible for the higher summer average TP on the shelf vs. pelagic waters and the exceedance of a TP water quality limit on the shelf. The effective simulation of PPₘ/ᵤ allows an appropriate adjustment of TP values to avoid overrepresentation of potential primary production levels.

As major endocrine disruptors, natural estrogens such as 17β-estradiol (E2) have been found with adverse effects on animals and humans. How to control E2 pollution as well as that of other estrogens in the environment is a worldwide concern. A novel E2-degrading bacterium (strain JX-2) was isolated from the activated sludge of a sewage treatment plant and was identified as Rhodococcus sp. Strain JX-2 grew well and metabolized up to 94 % of the substrate E2 added (30 mg L⁻¹) within 7 days at 30 °C. The optimal environmental conditions for E2 degradation by JX-2 were pH 7.0 and 30 °C. Strain JX-2 was immobilized in sodium alginate. The optimal conditions for strain JX-2 immobilization were 4 % sodium alginate, 1:1 bacteria/sodium alginate ratio, 5 % CaCl₂⋅2H₂O, and 6 h crosslinking time. The degradation performance of immobilized strain JX-2 was apparently superior to that of the free strain, particularly under pH <6.0 or >8.0 either below 20 or above 35 °C. Immobilized strain JX-2 removed E2 in natural sewage and cow dung with removal efficiency of more than 64 and 81 %, respectively. This is the first report of utilizing immobilized bacteria to remove estrogens in sewage and livestock manure. The results suggest that strain JX-2 could be used to remove E2 from the environment efficiently.

Amaranthus hybridus L. has great potential for use in phytoremediation of soils contaminated with cadmium (Cd). In this study, we found higher absorption of Cd by the roots of A. hybridus than by its other organs. To understand the mechanism of Cd accumulation in A. hybridus roots, a comparative proteomic approach was used to differentiate the two-dimensional electrophoretic profiles of root proteins in Cd-free and Cd-treated plants. Twenty-eight differentially expressed proteins were successfully identified using matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry. Of these, 10 were specifically expressed under Cd stress, and another 11 were upregulated and 7 downregulated by >2.5-fold under Cd stress. We observed increased expression of proteins involved in energy metabolism, protein metabolism, stress and defense, and signal transduction. These changes likely enhanced Cd tolerance and enrichment in A. hybridus. The downregulated proteins were mainly involved in the synthesis of microRNAs, cell walls, and other structural components. These observations were further confirmed by quantitative fluorescence PCR. The resulting differences in protein expression patterns suggest that redirection of root cell metabolism might be an important survival mechanism for A. hybridus under Cd stress.

The As(V) extraction in the pH-dependent As(V)-Fe(III) precipitates and the corresponding interaction mechanism of As(V) with ferric iron coagulant were systematically investigated in this study. Generally, As(V) removal by coagulation was more susceptible to the influence of the solution pH than that of the coagulant dosage. There was a distinctively bell-shaped pattern for As(V) removal with increasing the solution pHᵢₙᵢ from 4.6 to 9.4 with varied mass ratios of Fe/As. Specifically, the removal efficiencies of As(V) were enhanced progressively with increasing pH from 4.6 to 6.2. However, As(V) removal declined appreciably as pH further increased to 9.4. The maximum uptake capacities of As(V) by the precipitates were 1.21, 1.10, and 0.95 mg As per mg Fe at pHᵢₙᵢ 6.2 with the Fe/As mass ratio of 0.6, 0.8, and 1.0, respectively. Approximately 99 % of sorbed amorphous hydrous and crystalline hydrous oxide-bound As(V) were extracted in bearing-As(V) precipitates at relevant pHᵢₙᵢ values (i.e., 5.0, 7.0, and 9.0), implying that the main mechanism governing As(V) removal process was forming the inner sphere complexes, which can cause much more powerful forces than chemical compounds. Moreover, it has been accounted well with the performances of floc coagulation for As(V) removal evidenced by the characterizations of the floc size distribution, the floc fractal dimension, and the Fourier transform infrared spectroscopy (FT-IR) spectra, respectively. Considering that As extraction can provide insights for understanding As speciation and mobility in settled precipitates, this study will definitely count much in predicting the long-term risks of As-Fe sediments to the natural environment.

Porous asphalt (PA), porous concrete (PC), and permeable inter-locking pavers (PICP) with sub-surface layers consisting of different gravel sizes (63, 40, and 12 mm) commonly used in the bedding, base, and sub-base layers of permeable pavements were investigated for their ability to remove total suspended solids (TSS), total phosphorous (TP), and total nitrogen (TN). The investigation focused on the individual surface and sub-surface layers of the three permeable pavements to “treat” these pollutants and how the physical design of these layers influences their water quality treatment performance. This assessment was conducted with a laboratory study, but performances were also compared to data obtained from a field-scale study of pollutant removal in PA, PC, and PICP. Pollutant removal by a sub-surface layer and the particle size distribution of outflow are dependent on both the thickness of the layer and the gravel size. Superior performance in removing pollutants was found in PC’s surface layer compared to the surface layers of PA and PICP. The lab-scale pavements and the field-scale pavements have similar performance in removing pollutants for TSS (87–95 %) and TP (75–89 %) but not for TN (3–10 % for lab-scale and 2–40 % for field-scale pavements). A simple mathematical model based on these results was developed to provide estimates of performance in the field.

The Orcia River basin lies north of the Mt. Amiata mining district and may receive potentially harmful/toxic elements such as mercury (Hg) and arsenic (As) therefrom. The Orcia River eventually flows to the Ombrone River, which in turn flows to the Tyrrhenian Sea. The analysis of stream sediments collected in the Orcia River and its main tributaries, as well as in the Ombrone River, indicates moderate concentrations of both Hg and As (median values, Hg 118 μg/kg and As 5.25 mg/kg), rarely exceeding Italian environmental quality standards. Exceptionally high values for both elements are observed only in close proximity to the former Pietrineri Hg mine (Hg 195 mg/kg and As 35 mg/kg). Travertine and unconsolidated deposits associated with thermal springs in the area generally exhibit low Hg concentrations (4–320 μg/kg), with a significant exception of 23 mg/kg at Bagni San Filippo. Arsenic concentration in the same deposits is more variable with a peak level of 358 mg/kg. Surface waters collected at the same sites as stream sediments show Hg and As concentrations below the Italian mandatory limits for drinking waters (1 μg/L for Hg and 10 μg/L for As). Likewise, in thermal springs, Hg concentrations are low, whereas As concentrations are relatively high (up to 23.4 μg/L), which is in agreement with previous studies. At present, the input of toxic elements from the mining district into the Orcia and Ombrone watersheds is lower than inputs documented in the Paglia and Tiber catchments south of Mt. Amiata and does not pose an immediate environmental threat. However, the possible remobilization of Hg-contaminated sediments during flash flood events cannot be dismissed.

Traffic-based pollution causes accumulation of some elements in plant tissues and damages anatomical and physiological processes of plants. Nutrient use proficiency and litter decomposition are two basic processes of nutrient dynamics. This study aimed to determine the effects of traffic-based pollution on N and P use proficiency and litter decomposition in Malus domestica Borkh. (Rosaceae) which is a commonly cultivated fruit tree worldwide. The study was carried out in Amasya, Turkey, where the apple is the symbol of the city. Leaf samples were collected from apple trees at 0-, 100-, and 200-meter distances from the highway. N, P, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn concentrations were measured in the collected samples. All of the element concentrations varied according to the distance from the road. Traffic-based heavy metal pollution increased N and P use proficiency. It may be said that M. domestica reabsorb more N and P from senescent leaves due to the high heavy metal concentrations in their leaves. The decomposition rate was highest at 0 m and lowest at 100 m. The variations in the remaining dry weight, mass loss (%), and k value due to traffic-based pollution were not statistically significant. A significant negative relationship was determined between the initial N concentration and the litter decomposition rate. It was thought that this negative relationship resulted from recalcitrant condensation products that are formed by lignin and N.

Ecological light pollution occurs when artificial lights disrupt the natural regimes of individual organisms or their ecosystems. Increasing development of shoreline habitats leads to increased light pollution (e.g., from cottages, docks, automobile traffic), which could impact the ecology of littoral zones of lakes and rivers. Smallmouth bass (Micropterus dolomieu) engage in sole paternal care, guarding their nest continually, day and night, to protect their developing offspring. Any alterations to their behaviour—either directly because of the response to light or indirectly due to changes in nest predator activity and associated response of the bass—could lead to increased energetic demands for fish that have a fixed energy budget and ultimately reduce reproductive success. To examine this issue, tri-axial accelerometer biologgers were externally attached to nesting smallmouth bass during the egg stage to determine whether light pollution (i.e., dock lights with low levels of continuous light and spotlights with high intensity irregular light simulating automobile traffic) altered behaviour of nesting males relative to control fish. Our study revealed that both types of light pollution increased overall bass activity level compared with the control group. The intermittent light treatment group had the highest activity and exhibited large fluctuations between night and day activity levels. Fish in the continual light treatment group displayed statistically higher activity than the control fish but showed limited fluctuations between day and night activity levels. Our results suggest that continuous or intermittent light sources, common in shoreline habitats that have been developed, have the potential to alter the behaviour and thus energy use of nest-guarding fish. This study contributes to the growing body of literature on the ecological consequences of light pollution in aquatic ecosystems.