Photochemical transformation of pharmaceuticals plays an important role in their natural attenuation, especially in lagoon-based wastewater treatment plants and surface waters receiving substantial sunlight. In this study, the photodegradation of five important pharmaceuticals was studied in samples obtained from a wastewater treatment plant and surface water sources. Batch photodegradation studies for a mixture of pharmaceuticals (diclofenac, sulfamethoxazole, acetaminophen, carbamazepine and gemfibrozil) were carried out in a photochemical reactor. Multiple aliquots of samples removed from the reactor during the experiment were analyzed through high-performance liquid chromatography (HPLC) coupled to a photodiode array (PDA) detector. Intermediate products formed due to photodegradation were identified by ultra-high-performance liquid chromatography coupled with a time-of-flight mass spectrometry (UHPLC-MS/MS). Diclofenac and sulfamethoxazole were found to undergo direct photodegradation due to strong light absorption, whereas the indirect route of photosensitized degradation in the presence of dissolved organic matter (DOM) and model humic acid was significant for acetaminophen, carbamazepine, and gemfibrozil. The reactive radicals such as hydroxyl (OH•), singlet oxygen (1O2) and excited states of DOM (*DOM) were predominantly responsible for the indirect photodegradation of acetaminophen, gemfibrozil and carbamazepine, respectively. Computational analysis revealed that chlorine and carbon atoms belonging to the benzene ring of diclofenac were more reactive to radical attack. Sulfamethoxazole photodegradation occurred through oxidation of the NH2 group. Acetaminophen was more susceptible to electrophilic radical attack at the O-11, and N-7 positions and carbon atoms ortho to the phenolic oxygen and the amine group. The double bonds between C-7, C-8 and C-13 were the most reactive sites for carbamazepine that participated in the phototransformation pathway. Organic matter plays a critical role in the photodegradation of emerging contaminants. The coupling of DFT calculations with UHPLC-MS/MS analysis provided insights on key functional groups participating in the phototransformation pathway. Thus, both parent pharmaceuticals and the photodegradation intermediates should be considered during wastewater treatment.

Here, metal oxides/hydroxide (MO = (PdO)(n)center dot[Pd(OH)(2)](m), Co(OH)(2), and (PdO)(n)center dot[Pd(OH)(2)](m)/CoO, n > m) clusters were successfully co-loaded on the surface of acid-treated molten salt fluxed TiO2 nanorods (ATO-NRs) via conventional wet impregnation. The synergistic effect of palladium oxide/palladium hydroxide and cobalt oxide [((PdO)(n)center dot[Pd(OH)(2)](m)/CoO)] co-loading on ATO-NR demonstrated by the photocatalytic degradation of Orange II dye, bisphenol A and S. typhimurium inactivation under mimicked and unfiltered solar light (Xe arc lamp) radiation. Optimum [((PdO)(n)center dot[Pd(OH)(2)](m)/CoO)] co-loaded ATO-NRs exhibited significantly higher degradation efficiency (Orange II (91%) and BPA (97%) within 30 min of treatment) over (PdO)(n)center dot[Pd(OH)(2)](m) (n > m) and CoO/ATO-NRs under Xe arc lamp light radiation. Also, optimal sample showed higher inactivation efficiency for S. typhimurium than (PdO)(n)center dot[Pd(OH)(2)](m) (n > m)/ATO and CoO/ATO-NRs under UVA light radiation, however, the photocatalytic mechanisms for S. typhimurium inactivation was different than the BPA. Photoelectrochemical analyses demonstrated that the significantly accelerated charge-transfer process in metal oxides/hydroxide cluster [(PdO)(n)center dot[Pd(OH)(2)](m)/CoO] co-loaded ATO-NRs leading to higher degradation efficiency than other studied samples. Radical trapping supports h(+) and O-2(center dot-) as major reactive species, with OH center dot playing a secondary role in Orange II and BPA degradation. Cell membrane interruption by reactive oxygen species (ROS) and reactions of photocatalyst with the -NH and -COOH group of protein and metalloproteins, nucleic acid in bacterial cells could be the main cause in S. typhimurium disinfection. Plausible charge transport pathways were proposed for photocatalytic degradation of organic pollutants and bacterial inactivation over the (PdO)(n)center dot[Pd(OH)(2)](m)/CoO/ATO-NR's.

Bacillus bacteria have major utility in large-scale production of industrial enzymes, among which proteases have particular importance. B. subtilis B22, an aerobic and chemotrophic strain, was isolated from kimchi and identified by 16S rRNA gene sequencing. Extracellular protease production was determined in basic medium, with 1% (w/v) casein as substrate, by submerged fermentation at 37 °C under blue, green, red and white light-emitting diodes (LEDs), white fluorescent light and darkness. Fermentation under blue LEDs maximized protease production (110.79 ± 1.8 U/mL at 24 h). Various agricultural waste products enhanced production and groundnut oil cake yielded the most protease (334 ± 1.8 U/mL at 72 h). Activity and stability of the purified protease were optimum at pH 7–10 and 20–60 °C. Activity increased in the presence of Ca2+, Mg2+ and Mn2+, while Fe2+, Zn2+, Co2+ and Cu2+ moderated activity, and Ni2+ and Hg2+ inhibited activity. Activity was high (98%) in the presence of ethylenediaminetetraacetic acid (EDTA) but inhibited by phenylmethanesulfonyl fluoride (PMSF). The protease was unaffected by nonionic surfactants, tolerated an anionic surfactant and oxidizing agents, and was compatible with multiple organic solvents. These properties suggest utility of protease produced by B. subtilis B22 under blue LEDs for industrial applications.

Island populations are rarely studied for risk of arsenic (As) poisoning. As poisoning, multimetal contamination and people’s perceptions of health risks were assessed on India’s Majuli Island, the largest inhabited river island in the world. This holistic approach illustrated the association of groundwater contamination status with consequent health risk by measuring levels of inorganic arsenic (iAs) in groundwater, borehole sediment and biological samples (hair, nails and urine). Piper and Gibbs’s plots discerned the underlying hydrogeochemical processes in the aquifer. Demographic data and qualitative factors were evaluated to assess the risks and uncertainties of exposure. The results exhibited significant enrichment of groundwater with As, Mn and Fe along with significant body burden. Maximum Hazard Index values indicated severe non-carcinogenic health impacts as well as a significantly elevated risk of cancer for both adults and children. Most (99%) of the locally affected population did not know about the adverse health impacts of metal contamination, and only 15% understood bodily ailments and health issues. Various aspects of the island environment were used to elucidate the status of contamination and future risk of disease. A projection showed adverse health outcomes rising significantly, especially among the young population of Majuli, due to overexposure to not only As but also Ba, Mn and Fe.

A hydrothermally synthesized rhodium/antimony co-doped TiO2 nanorod and titanate nanotube (RS-TONR/TNT) composite was prepared for removal of heavy metals and organic pollutants from water under visible light irradiation. The composite provides the dual function of simultaneous adsorption of heavy metal ions and enhanced degradation of dissolved organic compounds. Acid treatment transformed titanate nanotubes to irregular tubular structures distributed homogeneously over untransformed RS/TONRs. Synergistic removal and degradation was studied with various heavy metals, Orange (II) dye, and Bisphenol A. The adsorption capacity of the composite for heavy metal ions was Pb(II) > Cd(II) > Cu(II) > Zn(II). The adsorbed metals enhanced photocatalytic degradation of the organic pollutants, but Cu was most effective, with degradation exceeding 70% for the dye and 80% for Bisphenol A after 5 h of treatment. Photocatalytic activity was enhanced more by adsorption than photodeposition of Cu ions. A decrease in XRD rutile peak intensity with adsorbed metal indicates a change in crystallinity which may enhance photocatalytic activity. Thick and bulging nanostructures in FE-SEM images signify ion adsorption within titanate pores. BET analysis indicated titanate nanotubes with adsorbed metal are mesoporous but their tubular structure persists. XPS showed more active Cu 2p3/2 states under light, supporting an active role of Cu+ in photocatalytic ROS generation. Detection of ROS and Cu species using methanol, EDTA, pCBA, and benzoic acid probes provided strong evidence for degradation via a charge transfer mechanism. Findings demonstrate the potential of the RS-TONR/TNT composite for simultaneous removal of heavy metals and degradation of organic pollutants.

The imprints of fireworks displays on the adjacent water body were investigated from the perspective of cogeneration of black carbon, metals and perchlorate (ClO4-). In particular, the mixing and dissipation of ClO4- were studied at Oak Lake, Lincoln, Nebraska, following fireworks displays in 2015 and 2016. Following the display, ClO4- concentration in the water increased up to 4.3 μg/L and 4.0 μg/L in 2015 and 2016, respectively. A first-order model generally provided a good fit to the measured perchlorate concentrations from which the rate of dissipation was estimated as 0.07 d-1 in 2015 and 0.43 d-1 in 2016. SEM images show imprints of soot and metal particles in aerosol samples. EDS analysis of the lake sediment confirmed the presence of Si, K, Ca, Zn and Ba, most of which are components of fireworks. The δ13C range of -7.55‰ to -9.19‰ in the lake water system closely resembles fire-generated carbon. Cogeneration of black carbon and metal with perchlorate was established, indicating that ClO4- is an excellent marker of fireworks or a burning event over all other analyzed parameters. Future microcosmic, aggregation and column-based transport studies on black carbon in the presence of perchlorate and metals under different environmental conditions will help in developing transport and fate models for perchlorate and black carbon particles.

A chemotrophic, aerobic bacterial strain, Bacillus subtilis B2, was used to produce amylase by submerged fermentation under different light sources. SDS-PAGE indicated that the 55 kDa enzyme belonged to the α-amylase group. B2 was incubated in basal media with 1% soluble starch (pH 7.0) under blue, green, red, and white light-emitting diodes (LEDs), and white fluorescent light. Fermentation under blue LEDs maximized amylase production (180.59 ± 1.6 U/mL at 24 h). Production at 48 h increased to 310.56 ± 1.6 U/mL with 5% glucose as a simple carbon source and to 300.51 ± 1.7 U/mL with 5% groundnut oil cake as an agricultural waste substrate. Activity and stability of the amylase were greatest at pH 7.0 and 45-55 °C. Na+, Ca2+, Mg2+, Co2+, Ba2+, and K+ increased activity, while Ni2+, Hg2+, Mn2+, Cu2+, Fe3+, and Zn2+ inhibited activity. EDTA, PMSF and DTNB reduced activity by 50% or more, while tetrafluoroethylene and 1,10-phenanthroline reduced activity by 30%. The amylase was highly tolerant of the surfactants, compatible with organic solvents, oxidizing agents and the reducing agents reduced activity. These properties suggest utility of amylase produced by B. subtilis B2 under blue LED-mediated fermentation for industrial applications.

For sustainable production, there is an urgent need to minimize the adverse environmental impacts of swine farming, which is a major contributor of the pollutants p-cresol and tylosin. Novel reactive composite alginate beads (CAB-MOACs) were fabricated by combining alginate with activated carbon (AC) and MnO2 recovered from spent battery waste and used for efficient removal of p-cresol and tylosin from water. Batch experiments were carried out under varying pH (3-11), temperature (15-50 degrees C), and agitation speed (50-200 rpm) to understand their effects on removal efficiency. The CAB-MOACs had better removal efficiency for p-cresol and tylosin than alginate beads alone or beads containing only AC or MnO2. Adsorption to CAB-MOACs followed pseudo-second-order kinetics (R-2 >= 0.98) and Langmuir isotherm models (R-2 >= 0.95). CAB-MOACs showed higher removal efficiency (similar to 99.9% after 10 h) compared to beads containing only immobilized MnO2 (60-70%) or AC (94-96%). Regeneration and reuse performance of the CAB-MOACs was excellent through five cycles, although slightly better for p-cresol than tylosin. With low-cost manufacturing and beneficial utilization of hazardous waste such as spent batteries, the newly developed composite beads show potential as an effective adsorbent for treating wastewater effluent containing emerging contaminants like p-cresol and tylosin. Future studies may focus on product refinement and large-scale testing on actual wastewaters.

Light and bacteria can be used in combination to enhance secondary metabolite production during fermentation. Red yeast rice powder (RYRP) was inoculated with Bacillus subtilis (B2) isolated from freshwater seafood and incubated under light-emitting diodes (LEDs) of different colors (blue, green, red, white), fluorescent white light, and in darkness. Blue LED-mediated fermentation with B2 significantly enhanced production of phenolic compounds (68.4 ± 1 mg GAE/g DW) and flavonoids (51.7 ± 1 mg QE/g DW) compared to white light and darkness. Total antioxidant activity of RYRP extract after fermentation with B2 was > 77%; hydroxyl radical and superoxide scavenging were > 66%. DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) and ABTS (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)) radical scavenging activities were 51% and > 67%, respectively. Reducing power was approximately twice that of extract from RYRP without B2. FTIR analysis showed a high content of hydroxyl, nitrile and carboxylic groups in the extract. Derivatives of cinnamic, benzoic and phophinodithioic acid, and quinazolinone were identified by GC–MS. Findings show that fermenting RYRP with B. subtilis B2 under blue LEDs enhances production of secondary metabolites, which should have applications in industrial fermentation processes.

Arsenic (As) and fluoride (F−) in groundwater are increasing global water quality and public health concerns. The present study provides a deeper understanding of the impact of seasonal change on the co-occurrence of As and F−, as both contaminants vary with climatic patterns. Groundwater samples were collected in pre- and post-monsoon seasons (n = 40 in each season) from the Brahmaputra flood plains (BFP) in northeast India to study the effect of season on As and F− levels. Weathering is a key hydrogeochemical process in the BFP and both silicate and carbonate weathering are enhanced in the post-monsoon season. The increase in carbonate weathering is linked to an elevation in pH during the post-monsoon season. A Piper diagram revealed that bicarbonate-type water, with Na+, K+, Ca2+, and Mg2+ cations, is common in both seasons. Correlation between Cl− and NO3 − (r = 0.74, p = 0.01) in the post-monsoon indicates mobilization of anthropogenic deposits during the rainy season. As was within the 10 µg L−1 WHO limit for drinking water and F− was under the 1.5 mg L−1 limit. A negative correlation between oxidation reduction potential and groundwater As in both seasons (r = −0.26 and −0.49, respectively, for pre-monsoon and post-monsoon, p = 0.05) indicates enhanced As levels due to prevailing reducing conditions. Reductive hydrolysis of Fe (hydr)oxides appears to be the predominant process of As release, consistent with a positive correlation between As and Fe in both seasons (r = 0.75 and 0.73 for pre- and post-monsoon seasons, respectively, at p = 0.01). Principal component analysis and hierarchical cluster analysis revealed grouping of Fe and As in both seasons. F− and sulfate were also clustered during the pre-monsoon season, which could be due to their similar interactions with Fe (hydr)oxides. Higher As levels in the post-monsoon appears driven by the influx of water into the aquifer, which drives out oxygen and creates a more reducing condition suitable for reductive dissolution of Fe (hydr)oxides. An increase in pH promotes desorption of As oxyanions AsO4 3− (arsenate) and AsO3 3− (arsenite) from Fe (hydr)oxide surfaces. Fluoride appears mainly released from F−-bearing minerals, but Fe (hydr)oxides can be a secondary source of F−, as suggested by the positive correlation between As and F− in the pre-monsoon season.

A Bacillus sp. strain (JH2-2), isolated from soil at an abandoned mine site, reduced Cr(VI) to Cr(III) under aerobic conditions. At pH 7, the strain reduced essentially all of the Cr(VI) in M9 minimal medium to Cr(III) at initial concentrations <= 50 mg Cr(VI) L-1 within 100 h. The X-ray diffraction pattern of the Cr(III) precipitate matched chromium (III) hydrogen phosphate (CrH2P3O10 center dot 2H(2)O). The JH2-2 strain showed high tolerance to other heavy metal(loid)s, with minimal inhibitory concentrations in liquid medium of (mg L-1): As (500), Cd (100), Cu (350), Ni (300), Zn (200), and Pb (1800). JH2-2 also promoted decolorization of methylene blue dye. Decolorization was faster in the presence of 10 mg Cr(VI) L-1 than in the absence of Cr(VI). A lag in decolorization at 30 and 50 mg Cr(VI) L-1 is likely due to initial toxicity and inhibition of bacterial growth. The chemistry of MB is complicated by its reduction to colorless leucomethylene blue, which can reoxidize to MB. However, aeration of the solution did not restore measurable MB, supporting removal of the dye via biosorption. Results indicate the bioremediation potential of Bacillus sp. JH2-2 for simultaneous Cr(VI) reduction and methylene blue removal from contaminated water.

The Barney M. Davis Power Plant in Corpus Christi, Texas, withdraws large quantities of water from the Laguna Madre for non-contact cooling. As a result, fish and shellfish may be harmed when impinged against screens intended to remove debris and wrack (floating sea grass). To reduce impingement it is important to understand related factors and their interrelationships. Several operational, water quality, and temporal factors were correlated with the total number of impinged organisms when the plant is pumping water. In this study, operational factors included hourly average flow and the number of screens in operation during sampling. Water quality factors included temperature, dissolved oxygen, pH, conductivity and salinity. Temporal factors included month and time of day of impingement sampling. Over the course of a year, fish and shellfish impinged on Passavant traveling drum screens were collected, classified, and counted. Multiple regression analyses were conducted and the number of organisms impinged was the response variable. Total impingement was most associated with dissolved oxygen concentration, sampling month and sampling time. For fish, sampling month and dissolved oxygen were most associated with impingement, while for shellfish, sampling month and sampling time were most important. Hourly flow and number of operating screens were not significant predictors of impingement.

The potential of a lead (Pb)-tolerant Pseudomonas sp. JH 51-2 strain to promote Pb stabilization was evaluated in mining site soil. The strain was isolated from soil containing multiple heavy metals. Transmission electron microscopy (TEM) showed that cell walls were surrounded by extracellular substances and scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) confirmed the presence of Pb on the surface of cell membrane. Fourier transform infrared spectroscopy (FTIR) revealed that amino acids, phospholipids and extracellular polysaccharides were involved in Pb complexation and biosorption. Sequential extraction and toxicity characteristic leaching procedure (TCLP) showed decreased Pb availability in mining site soil in the presence of Pseudomonas sp. JH 51-2. Results indicate that Pseudomonas sp. JH 51-2 is an efficient biological stabilizer of Pb in contaminated soil.

Endophytic bacteria have the potential to promote plant growth and heavy metal(loid) (HM) removal from contaminated soil. Pseudomonas koreensis AGB-1, isolated from roots of Miscanthus sinensis growing in mine-tailing soil, exhibited high tolerance to HMs and plant growth promoting traits. Transmission electron microscope (TEM) analysis revealed that AGB-1 sequestered HMs extracellularly and their accumulation was visible as dark metal complexes on bacterial surfaces and outside of the cells. DNA sequencing of HM resistance marker genes indicated high homology to the appropriate regions of the arsB, ACR3(1), aoxB, and bmtA determinants. Inoculating mining site soil with AGB-1 increased M. sinensis biomass by 54%, chlorophyll by 27%, and protein content by 28%. High superoxide dismutase and catalase activities, and the lower malondialdehyde content of plants growing in AGB-1-inoculated soil indicate reduced oxidative stress. Metal(loid) concentrations in roots and shoots of plants grown in inoculated soil were higher than those of the controls in pot trials with mine tailing soil. Results suggest that AGB-1 can be used in association with M. sinensis to promote phytostabilization and remediation of HM-contaminated sites.

Bacillus sp. strain JH 2‐2, isolated from the rhizosphere of plants at a multi‐metal contaminated mine site, has the potential to reduce Cr(VI) to Cr(III) and promote plant growth by reducing Cr toxicity and producing IAA. The minimum inhibitory concentration of Cr(VI) to Bacillus sp. JH 2‐2 was 1000 mg L−1 and the strain reduced 99% of 10 mg Cr(VI) L−1 to Cr(IV) within 24 h. Lower Cr(VI) stress (10 mg L−1) stimulated IAA production, but much less IAA was produced at 30 or 50 mg Cr(VI) L−1. Inoculation with Bacillus sp. JH 2‐2 increased the length of Brassica juncea L. roots by 364% and stems by 735% in the presence of 10 mg Cr(VI) L−1 from those of uninoculated control plants. These findings suggest potential use of Bacillus sp. JH 2‐2 to promote phytoremediation of soil contaminated with Cr(VI).

The wide use of cadmium (Cd) in batteries and semiconductors poses human and environmental health hazards when these materials are disposed. Citrobacter sp. JH 11-2, isolated from soil at an abandoned mining site, shows potential for use as a biosorbent for Cd removal from aqueous solution. A minimal inhibitory concentration of 300 mg L−1 indicated high tolerance of the strain to Cd. The strain effectively removed 47.7% of the Cd from a 100 mg L−1 solution within 160 h. Cell fractioning revealed that most of the Cd (43.5%) was in the membrane fraction, while 38.5% was in the peptidoglycan layer and 18.0% was in the cytoplasmic fraction. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of functional groups on dried Citrobacter sp. JH 11-2 cells that can adsorb or complex Cd ions. A Langmuir model provided a good fit to Cd removal by the cells, which followed pseudo-second-order kinetics. Results support further development of Citrobacter sp. JH 11-2 as a biosorbent for Cd removal.

Treating mixed contaminants with zerovalent iron (Fe-0) for environmental remediation requires a thorough understanding of the competition among electron acceptors. The authors conducted aqueous batch tests to determine competitive reduction of nitrate, nitrite, and nitrobenzene by Fe-0 under varying conditions. Results indicate that nitrate reduction by Fe0 was accompanied by substantial Fe-0 oxidation by water. Nitrite and nitrobenzene were concomitantly reduced by Fe-0, forming a lepidocrocite (gamma-FeOOH) coating on the Fe-0 grains. When present together, nitrite and nitrobenzene reduction proceeded without apparent interference from nitrate. Nitrate reduction, however, did not occur in the presence of nitrite or nitrobenzene. Adding aqueous Fe(II) facilitated nitrate reduction by Fe-0, but not until the lepidocrocite coating on the Fe-0 grains was transformed to magnetite (Fe3O4), a process that is significantly accelerated by surface-bound Fe(II). This study illustrates the relative reactivity of F(e)0 towards specific compounds and the related formation and compositional evolution of the iron oxide coating in Fe-0-water systems. (C) 2014 American Society of Civil Engineers.

•PDR-4 and PDR-16 had As, Cu, Pb and Zn tolerance and plant growth-promoting traits.•The fungi increased mobilization of P and heavy metals in mine tailing soil.•Soil inoculation promoted growth and As, Pb and Zn uptake by sorghum-sudangrass.•Co-inoculation was more effective than using single isolates.•The fungi can promote phytoremediation and biomass production on mine tailing soil.