Br⁻and nitrogen-containing organic pollutants, such as amino acids, protein, etc., were often detected in water and wastewater treatment plants using advanced oxidation technologies. All these technologies have one common characteristic, that is, the removal processes involve ·OH. Therefore, it is necessary to study the different reaction pathways among ·OH, Br⁻, and amino acids. In this research, glycine was chosen as the representative of amino acids and H₂O₂was selected as ·OH precursor. Results showed that Br⁻had a shielding effect on H of α-carbon in glycine, when it was abstracted by ·OH. The main reaction pathway in the system containing Br⁻was the abstraction of H from amino group in glycine by ·OH, contributing 85 % of total abstracted H. This system had a prominent phenomenon of decarboxylation and performed as alkali production dominating. However, in the system not containing Br⁻, the main reaction pathway was the abstraction of H from α-carbon in glycine by ·OH, contributing 97 % of total abstracted H. This system performed as acid production dominating. By laser flash photolysis, the second-order rate constants of abstraction of H from both α-carbon and amino group in glycine by ·OH were obtained as (3.3 ± 0.5) × 10⁷M⁻¹·s⁻¹and (8.2 ± 0.8) × 10⁸ M⁻¹·s⁻¹, respectively. The second-order rate constants of the reaction between H₂NCH₂COO⁻, HṄCH₂COO⁻ and H₂O₂ were (1.5 ± 1.1) × 10⁷ M⁻¹·s⁻¹and (4.4 ± 0.3) × 10⁷ M⁻¹·s⁻¹, respectively. In addition, Br⁻was found to play a catalytic role in the decomposition of H₂O₂under UV radiation. The results mentioned above were significant for the application of advanced oxidation technologies for water containing both amino acids and Br⁻in water and wastewater treatment plants.

Photocatalytic degradation of 17α-ethynylestradiol (EE2) using TiO₂photocatalysts incorporated with foam concrete (TiO₂/FC) was investigated for the first time. Scanning electron microscopy (SEM) study of the samples revealed a narrow air void size distribution on the surface of FC cubes on with 5 wt% addition of P25 TiO₂, and TiO₂particles were distributed heterogeneously on the surface of TiO₂/FC samples. The sorption and photocatalytic degradation of EE2 with UV-light irradiation by TiO₂/FC cubes were investigated. Adsorption capacity of EE2 by the TiO₂/FC and blank foam concrete (FC) samples were similar, while the degradation rates showed a great difference. More than 50 % of EE2 was removed by TiO₂/FC within 3.5 h, compared with 5 % by blank FC. The EE2 removal process was then studied in a photoreactor modified from ultraviolet disinfection pool and constructed with TiO₂/FC materials. An integrated model including a plate adsorption-scattering model and a modified flow diffusion model was established to simulate the photocatalytic degradation process with different radiation fields, contaminant load, and flow velocity. A satisfactory agreement was observed between the model simulations and experimental results, showing a potential for the design and scale-up of the modified photocatalytic reactor.

The effects of two formulations (emulsifiable concentrate (EC) and granule (G)) on the distribution, degradation, sorption, and residue risk of chlorpyrifos (CHP) were investigated in two producing areas of bamboo shoot. The results showed that CHP was mainly distributed in the topsoil (0–5 cm, P < 0.05), with the proportion of CHP in the total quantity ranging from 76.0 to 100.0 % (G) and 12.0 to 98.1 % (EC), respectively. The degradation of CHP-EC in soils (half-life 27.7–36.4 days) was faster than that of CHP-G in soils (half life above 120–150 days). The main metabolite of CHP, 3,5,6-trichloro-2-pyridinol (TCP), was found in soil samples. CHP showed good sorption ability in the two tested soils, with the sorption coefficient (KF) of 43.76 and 94.43 mg/kg. The terminal residues of CHP in bamboo shoots were in the range of 15.2–75.6 (G) and 10.4–35.7 μg/kg (EC), respectively. The soil type had a notable effect on the CHP behaviors in soil (P < 0.05, especially for CHP-G), but it did not affect the metabolite of CHP. Although some positive bamboo shoot samples (CHP residue exceeding maximum residue limits) were found, the hazard quotients did not exceed 7 %, which meant there was a negligible risk associated with the exposure to CHP via the consumption of bamboo shoots.

In the present study, the concentrations of trace and alkali metals in leaves of four common helophytes, Sparganium erectum, Glyceria maxima, Phalaris arundinacea, and Phragmites australis, as well as in corresponding water and bottom sediments were investigated to ascertain plant bioaccumulation ability. Results showed that Mn and Fe were the most abundant trace metals in all plant species, while Co and Pb contents were the lowest. Leaves of species studied differed significantly in respect of element concentrations. The highest concentrations of Mg, Na, Fe, Mn, Cu, Pb, and Ni were noted in S. erectum while the highest contents of Co, Ca, Zn, and Cr in Phalaris arundinacea. Phragmites australis contained the lowest amounts of most elements. Concentrations of Co, Cr, Fe, and Mn in all species studied and Ni in all except for Phragmites australis were higher than natural for hydrophytes. The leaves/sediment ratio was more than unity for all alkali metals as well as for Cu and Mn in Phragmites australis; Cr, Co, and Zn in Phalaris arundinacea; Cr and Mn in S. erectum; and Cr in G. maxima. High enrichment factors and high levels of toxic metals in the species studied indicated a special ability of these plants to absorb and store certain non-essential metals and, consequently, their potential for phytoremediation of contaminated aquatic ecosystems.

Workplace exposure to persistent organic pollutants is a concern for human health. This study examined the presence of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in the indoor dust from two major e-waste recycling sites and a university electronic equipment repair workshop in Durban, South Africa, in order to evaluate the implication of dust for occupational exposure. The mean ∑₍ₙ ₌ ₈₎PBDEs and ∑₍ₙ ₌ ₃₎PCBs were 20,094 and 235 ng g⁻¹, respectively. The levels of PBDEs and PCBs obtained in one of the recycling sites (123–27,530 and 161–593 ng g⁻¹) were significantly higher than the levels obtained (91–7686 and <DL–42 ng g⁻¹, respectively) in the same site after site cleanup/maintenance. Occupational exposure was assessed for different exposure scenarios by using the 5th and 95th percentile, and the median and mean concentrations measured at the sites. By assuming a mean and a high dust intake rate, the average and 95th percentile daily exposure doses (∑DED/ng kg⁻¹ bw day⁻¹) of PBDEs were 3.98, 8.52 and 7.58, 16.19, respectively, and of PCBs were 0.047, 0.094 and 0.089, 0.179, respectively. The ∑DEDs of PBDEs and PCBs were lower than the reference (RfD) values for BDE 47, BDE 99, BDE 153 and BDE 209, and Aroclor 1254 and 1016. Nevertheless, continual exposure to high levels of these pollutants is a concern; but as shown, the exposure can be significantly reduced if the e-waste facilities are cleaned thoroughly regularly.

Silicon (Si) is as an important fertilizer element, which has been found effective in enhancing plant tolerance to variety of biotic and a-biotic stresses. This study investigates the Si potential to alleviate zinc (Zn) toxicity stress in cotton (Gossypium hirsutum L.). Cotton plants were grown in hydroponics and exposed to different Zn concentration, 0, 25, and 50 μM, alone and/or in combination with 1 mM Si. Incremental Zn concentration in growth media instigated the cellular oxidative damage that was evident from elevated levels of hydrogen peroxide (H₂O₂), electrolyte leakage, and malondialdehyde (MDA) and consequently inhibited cotton growth, biomass, chlorophyll pigments, and photosynthetic process. Application of Si significantly suppressed Zn accumulation in various plant parts, i.e., roots, stems, and leaves and thus promoted biomass, photosynthetic, growth parameters, and antioxidant enzymes activity of Zn-stressed as well unstressed plants. In addition, Si reduced the MDA and H₂O₂production and electrolyte leakage suggesting its role in protecting cotton plants from Zn toxicity-induced oxidative damage. Thus, the study indicated that exogenous Si application could improve growth and development of cotton crop experiencing Zn toxicity stress by limiting Zn bioavailability and oxidative damage.

Response surface methodology (RSM) and central composite design (CCD) were used to develop models for optimization and modeling of a gas sparging assisted microfiltration of oil-in-water (o/w) emulsion. The effect of gas flow rate (Q G), oil concentration (C ₒᵢₗ), transmembrane pressure (TMP), and liquid flow rate (Q L) on the permeate flux and oil rejection were studied by RSM. Two sets of experiments were designed to investigate the effects of different gas–liquid two-phase flow regimes; low and high gas flow rates. Two separate RSM models were developed for each experimental set. The oil concentration and TMP were found to be the most significant factors influencing both permeate flux and rejection. Also, the interaction between these parameters was the most significant one. At low Q G , the more the gas flow rate, the higher the permeate flux; however, in the high gas flow rate region, higher Q G did not necessarily improve the permeate flux. In the case of rejection, gas and liquid flow rates were found to be insignificant. The optimum process conditions were found to be the following: Q G = 1.0 (L/min), C ₒᵢₗ = 1,290 (mg/L), TMP = 1.58 (bar), and Q L = 3.0 (L/min). Under these optimal conditions, maximum permeate flux and rejection (%) were 115.9 (L/m²h) and 81.1 %, respectively.

We present here observations on diurnal and seasonal variation of mixing ratio and δ¹³C of air CO₂, from an urban station—Bangalore (BLR), India, monitored between October 2008 and December 2011. On a diurnal scale, higher mixing ratio with depleted δ¹³C of air CO₂ was found for the samples collected during early morning compared to the samples collected during late afternoon. On a seasonal scale, mixing ratio was found to be higher for dry summer months (April–May) and lower for southwest monsoon months (June–July). The maximum enrichment in δ¹³C of air CO₂ (−8.04 ± 0.02‰) was seen in October, then δ¹³C started depleting and maximum depletion (−9.31 ± 0.07‰) was observed during dry summer months. Immediately after that an increasing trend in δ¹³C was monitored coincidental with the advancement of southwest monsoon months and maximum enrichment was seen again in October. Although a similar pattern in seasonal variation was observed for the three consecutive years, the dry summer months of 2011 captured distinctly lower amplitude in both the mixing ratio and δ¹³C of air CO₂ compared to the dry summer months of 2009 and 2010. This was explained with reduced biomass burning and increased productivity associated with prominent La Nina condition. While compared with the observations from the nearest coastal and open ocean stations—Cabo de Rama (CRI) and Seychelles (SEY), BLR being located within an urban region captured higher amplitude of seasonal variation. The average δ¹³C value of the end member source CO₂ was identified based on both diurnal and seasonal scale variation. The δ¹³C value of source CO₂ (−24.9 ± 3‰) determined based on diurnal variation was found to differ drastically from the source value (−14.6 ± 0.7‰) identified based on seasonal scale variation. The source CO₂ identified based on diurnal variation incorporated both early morning and late afternoon sample; whereas, the source CO₂ identified based on seasonal variation included only afternoon samples. Thus, it is evident from the study that sampling timing is one of the important factors while characterizing the composition of end member source CO₂ for a particular station. The difference in δ¹³C value of source CO₂ obtained based on both diurnal and seasonal variation might be due to possible contribution from cement industry along with fossil fuel / biomass burning as predominant sources for the station along with differential meteorological conditions prevailed.

Pollution control initiatives in Greater Sudbury, Ontario, Canada, resulted in the decommissioning of the Coniston Smelter in 1972. The last assessment of the effects from the smelter on the surrounding lichen biota was in 1990, which showed an overall improvement in richness following these initiatives, but still few species were present close to the smelter. We examined five sites along this gradient to determine if this pattern is still present on the landscape. Sixty-four macrolichen species in 15 genera were found. Lichen richness and Shannon diversity increased at all sites, but the increase was no longer linear with distance from the smelter. There was no significant difference between lichen richness and diversity at sites at increasing distances from the smelter. We show that past air pollution from the Coniston Smelter is no longer restricting lichen growth and development in the Greater Sudbury area as it was historically. Lichen populations are, therefore, now shaped by other environmental variables.

Trichoderma asperellum H15, a previously isolated strain characterized by its high tolerance to low (LMW) and high molecular weight (HMW) PAHs, was tested for its ability to degrade 3–5 ring PAHs (phenanthrene, pyrene, and benzo[a]pyrene) in soil microcosms along with a biostimulation treatment with sugarcane bagasse. T. asperellum H15 rapidly adapted to PAH-contaminated soils, producing more CO₂than uncontaminated microcosms and achieving up to 78 % of phenanthrene degradation in soils contaminated with 1,000 mg Kg⁻¹after 14 days. In soils contaminated with 1,000 mg Kg⁻¹of a three-PAH mixture, strain H15 was shown to degrade 74 % phenanthrene, 63 % pyrene, and 81 % of benzo[a]pyrene. Fungal catechol 1,2 dioxygenase, laccase, and peroxidase enzyme activities were found to be involved in the degradation of PAHs by T. asperellum. The results demonstrated the potential of T. asperellum H15 to be used in a bioremediation process. This is the first report describing the involvement of T. asperellum in LMW and HMW-PAH degradation in soils. These findings, along with the ability to remove large amounts of PAHs in soil found in the present work provide enough evidence to consider T. asperellum as a promising and efficient PAH-degrading microorganism.