In this work, the removal of methylene blue by Bacillus thuringiensis (Bt) 016 was investigated through batch experiments and microscopic investigations. It was found that methylene blue could not affect the growth of B. thuringiensis 016 at the concentration ranging from 5 to 25 mg/L, and be removed with the increase of biomass. Further studies indicated that Bt 016 biomass possessed strong ability of methylene blue biosorption with a quick process. Twenty-five milligrams of methylene blue per liter could be completely biosorbed within 2 h. The pH value could affect the removal of methylene blue in a large extent. UV–visible, Fourier transform infrared (FT-IR) spectroscopy analyses, and microscopic investigations suggested that the removal of methylene blue could be divided into two steps as follows: (1) rapid biosorption of methylene blue on Bt 016 biomass through electrostatic attraction or chelating activity of functional groups; (2) methylene blue was further degraded by Bt 016 through enzyme-mediated or couple with the metabolism process.

Rhamnolipid is a biosurfactant produced by several Pseudomonas species, and can wet hydrophobic soils by lowering the cohesive and/or adhesive surface tension. Because of its biodegradability, rhamnolipid is believed to have minimal adverse impact on the soil and groundwater after usage. Applications of rhamnolipid to improve irrigation in agricultural soils thus have obvious advantages over other chemical wetting agents, especially under drought conditions. Due to global warming, soil amendment with biochar has been commonly practiced in agricultural soils to increase the soil water-holding capacity. As such, rhamnolipid transport in biochar-amended agricultural soils needs to be characterized. In this research, we found that rhamnolipid transport in biochar-amended agricultural soils was hindered by retardation (equilibrium adsorption) and deposition (kinetic adsorption), which was well represented by the advection-dispersion equation based on a local equilibrium assumption. A linear equilibrium adsorption was assumed in the advection-dispersion equation simulation, which was proved to be acceptable by studying the breakthrough curves. Both rhamnolipid equilibrium adsorption and kinetic adsorption increased with the increase of the biochar content in the agricultural soil.

Scallop shell-Fe₃O₄ nanoparticles were synthesized by co-precipitation and hydrothermal methods. The removal efficiency of RB5 was studied as a function of pH, adsorbent dosage, initial RB5 concentration, ionic strength, and temperature. Coating of Fe₃O₄ nanoparticles onto Scallop shell was identified by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) analysis. Maximum adsorption was obtained at pH 3. The removal efficiency of RB5 was increased with increasing adsorbent dosage. However, it was decreased with increasing initial RB5 concentration, temperature and in the presence of any anions. Adsorption kinetic study revealed that the pseudo-second order model better described the removal rate than the pseudo-first order model and intra-particle diffusion model. Adsorption isotherm was analyzed by both Langmuir and Freundlich equation. Experimental result was well described by the Langmuir equation. Maximum adsorption capacity was estimated to be 1111.11 mg/g. Thermodynamic studies indicated that the adsorption of RB5 onto Scallop shell-Fe₃O₄ nanoparticles was an endothermic (∆H = 178.14 KJ mol⁻¹) process. The negative values of free energy (∆G) for the adsorption indicated that adsorption of RB5 was spontaneous reaction. Adsorption activity of RB5 by Scallop shell-Fe₃O₄ nanoparticles was maintained even after six successive cycles.

The influence of long-term exposure to background pollution on the response and recovery of the invasive species Corbicula fluminea to ammonia stress was investigated using a multi-marker approach. Wild clams of the tidal freshwater areas of two estuaries of the NW Iberian coast with different levels of pollution, the estuaries of Minho river (reference) and of Lima river (contaminated), were collected and exposed individually to different treatments: 8 and 14 days in dechlorinated tap water (DTW), 8 and 14 days in 1 mg L⁻¹of ammonia (AM), and 8 days in AM followed by 6 days in DTW. After each defined time (0, 8, and 14 days), the clams were sacrificed and the activity of the enzymes glutathione S-transferase (GST), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), cholinesterase (ChE), octopine dehydrogenase (ODH), and the lipid peroxidation (LPO) levels were used as effect criteria. At the beginning of the bioassay, the clams from the polluted estuary presented significantly higher background levels of GST, CAT, GR, GPx, and LPO than those from the reference one indicating long-term exposure to oxidative stressors. In general, C. fluminea from both estuaries presented little sensibility to ammonia with no significant differences found between exposed and control clams for most of the biomarkers. That low sensibility of C. fluminea could be seen as advantageous for its invasion ability.

In the present work, the role of chemical compounds of one abundant vegetable waste, exhausted coffee, on Cr(VI), Cu(II), and Ni(II) sorption has been investigated. For this purpose, exhausted coffee was subjected to sequential extractions by using dichloromethane (DCM), ethanol (EtOH), water, and NaOH 1 %. The raw and treated biomass resulting from the extractions were used for metal ions sorption. Sorption results were discussed taking into consideration polarity and functional groups of raw and treated biomass. In general, the successive removal of extractives led to an insignificant increase in the studied metal ions sorption after DCM, EtOH, and water. The sorption results using free-extractive materials showed that metal sorption can be effectively achieved without this non-structural fraction of the sorbent. Alkaline hydrolysis destroyed in part the structural compounds of the sorbent resulting in an insignificant decrease of chromium removal while a significant increase of copper and nickel sorption was observed. The determination of elemental ratios of exhausted coffee and all treated biomass evidenced the involvement of oxygen functional groups in copper and nickel sorption. FTIR analysis confirmed the involvement of lignin moieties in the chromium sorption by exhausted coffee. As a final remark, this study shows that the sequential extraction opens new expectations to the total valorisation of lignocellulosic-based biomasses. The extractives can be removed and used as a biosource of valuable compounds, and the resulting waste can be used as a sorbent for metal ions keeping the same capacity for metal sorption as the non-extracted biomass.

Stir bar sorptive extraction (SBSE) and solid phase microextraction (SPME) are well-established sample preparation methods for the analysis of polycyclic aromatic hydrocarbons in aqueous samples. However, complex matrices especially characterized by slurry particles and dissolved organic matter (DOM) can hamper the extraction of PAH with both SBSE and SPME and lead to different results. Thus, we produced aqueous eluates from PAH-contaminated soils differing in particle size distribution and organic matter content and determined the PAH concentration in the eluates with both SBSE and SPME. Furthermore, we tested the influence of filtration on the PAH analysis. The excess finding of PAH with SBSE compared to SPME ranged from −16.6 to 24.5 %. The differences increased after filtration. We found a strong positive correlation of the excess finding to the total organic carbon content (TOC) and a negative one to the pH value. The results indicate that SBSE is less affected by complex matrices than SPME.

This study investigates the impacts on the Australian native eastern long-necked turtle Chelodina longicollis of wetland waters derived from (1) precipitation and groundwater flow and wetlands also supplemented with (2) irrigation runoff from agricultural lands, (3) tertiary-treated sewage effluent and (4) harvested stormwater. Influences of water quality parameters on population attributes of the turtle population are considered. A total of 951 C. longicollis were captured in a mark-recapture study over 8 months. Overall, a female sex ratio bias was observed, and a larger number of smaller turtles were found in wetlands not contaminated by recycled tertiary-treated effluent. Dissolved oxygen, temperature, surface area and emergent vegetation had the greatest impact on turtle population structure. The lower the dissolved oxygen, the smaller the surface area of the wetland, and the higher the percentage of emergent vegetation, the greater the number of juveniles present. Water quality parameters which would be detrimental to fish predators appear to provide a ‘safe haven’ for juvenile turtles at the most vulnerable life stage of turtles.

Integrating vegetation into architecture has become widely recognized as a multi-beneficial practice in architecture and engineering design to combat an array of environmental issues. Urban areas have microclimates that are different than the climates of their surrounding rural areas. Patterns in these differences over the years have shown that urban microclimates tend to be significantly warmer in comparison. This phenomenon is now recognized as the urban “heat island” effect. While the associated consequences of this urban heating are far reaching, excess energy expenditure, air pollution emissions, and threats to human health are among the most critical for evaluation. The integration of vegetative green space in urban planning, coupled with highly reflective materials in place of conventional paved surfaces on roads and rooftops have proven to be effective methods of urban heat island mitigation. While as separate entities these methods are effective, innovative technology has brought forth greening roofs which allows vegetation to compensate where other roof-cooling strategies fall short. Substantially, vertical greenery systems compensate where greening roofs fall short. This paper explores both integrated vegetation as an optimal mitigation strategy for urban heat islands and vertical plant walls as an optimal design.

Representative sediment samples rich in nitrogen and phosphorus (both continuous and intermittently submerged) were used to conduct dynamic water level (WL) regulation experiments with various WL velocity modes (0, 3, and 6 cm/day). The experiments lasted three WL regulating cycles (6 months), and each single cycle included four WL dynamic phases: decline, stable, ascend, and re-stable. During the experiment, a greater nutrient stock caused higher nutrient release fluxes for continuously submerged sediments when compared to corresponding intermittently submerged sediments regardless of WL regulation. Moreover, continuous submerged sediment nutrient release showed a similar “U” pattern to the intermittently submerged sediment, and nutrient concentrations within the water phase generally increased with rising WL and decreased with dropping WL. Rapid WL regulation such as 6 cm/day promoted nitrogen release, and slow WL regulation at 3 cm/day favored phosphorus leaching. When three WL regulation cycles were finished, WL regulation of 6 cm/day resulted in 18 and 25 % decline of sediment mean organic matter (OM) content for continuous and intermittently submerged sediment, respectively. However, increased WL regulation cycles impacted on sediment nitrogen and phosphorus stock in different manners. For example, a WL regulation of 6 cm/day led to a 582 mg/kg decline and 322 mg/kg increase for intermittently submerged sediment in terms of total nitrogen (TN) and total phosphorus (TP) content, respectively. Results indicated that direct WL regulation insignificantly affected sediment nutrient release, but changed the overlying water conditions such as pH and redox potential (redox), and then indirectly changed the nutrient release dynamics.

The reversible and resistant components of adsorption and desorption of munition constituents (MCs) on soils was studied to determine the environmental fate of these contaminants. The long-term desorption of MCs has applicability in formulating accurate risk assessments for operational military ranges. Batch experiments near 1:1 (w/v) soil-to-solution ratios reflecting field conditions using solutions containing mixtures of HMX, RDX, and nitroglycerine (NG) were conducted. The three soils used varied from 0.04 to 13.3 % organic matter. The experiment involved one adsorption step followed by four consecutive desorption steps. Adsorption times were 2, 5, 10, and 30 days. For each adsorption time, desorption times were carried out for 1, 12, 24 and 72 h and 30 days. The reversible/resistant component model was applied to the data. The model predicted the desorption concentrations of the MCs in the soil with root mean square errors of approximately 0.05 to 0.2 μg g soil⁻¹. The extent of desorption hysteresis is not changed by the length of desorption time, irrespective of the initial adsorption time.