Sorptive removal of phenolic endocrine disruptors by functionalized biochar: Competitive interaction mechanism, removal efficacy and application in wastewater

© 2017 Elsevier B.V. Sorptive removal of six phenolic endocrine disrupting chemicals (EDCs) estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethynylestradiol (EE2), bisphenol A (BPA) and 4-tert-butylphenol (4tBP) by functionalized biochar (fBC) through competitive interactions was investigated. EDC sorption was pH dependent with the maximum sorption at pH 3.0–3.5 due to hydrogen bonds and π-π interactions as the principal sorptive mechanism. Sorption isotherm of the EDCs was fitted to the Langmuir model. Sorption capacities and distribution coefficient values followed the order E1 > E2 ≥ EE2 > BPA > 4tBP > E3. The findings suggested that EDC sorption occurred mainly through pseudo-second order and external mass transfer diffusion processes, by forming H-bonds along with π-π electron-donor–acceptor (EDA) interactions at different pH. The complete removal of ∼500 μg L−1 of each EDC from different water decreased in the order: deionised water > membrane bioreactor (MBR) sewage effluent > synthetic wastewater. The presence of sodium lauryl sulphonate and acacia gum in synthetic wastewater significantly suppressed sorption affinity of EDCs by 38–50%, hence requiring more fBC to maintain removal efficacy

SURVEY OF THE PRESENT STATUS OF STREET TREE PLANTING IN COLOMBO MUNICIPAL COUNCIL AREA and SOME RECOMMENDATIONS FOR IMPROVEMENTS

Urban Forestry embraces parks, avenue planting or street trees, boulevards, cemeteries,parking places etc. It plays an important role by providing aesthetic beauty andenvironmental pollution by absorbing vehicular emission. Colombo, which is thecommercial capital of Sri Lanka, is plaqued with high population density and highcommercial activities. Urban forestry has II significant potential in improving aesthetic &environmental aspects of the city.Objectives of this research project were to identify the existing situation of the street treeplanting in the 15 sub divisions of the Colombo Municipal Council Area and to give somerecommendations for improvements. 2 trunk roads were selected per division randomlyand the status of trees in these roads was recorded. Measurements of crown size, height,diameter at breast height, height of the first branching, widths of roads, sidewalks, andcenter medians were measured and recorded. Observations done in status of maturity, pestdiseaseattack, root pattern, foliage characteristics such as whether easily decayable ormoderately decayable and small or large leaves, land use patterns such as commercial,service & administration, residential and recreational land use & recorded.According to the results, a difference in the status of street trees in the 15 sub divisions inthe Colombo Municipal Council Area was identified. The sub divisions can be rankedaccording to the total crown area per kilometer as follows: sub divisions 7, 14, 3, 11, I, 2,5, 10,6, 13, 12, 15,8,9 & 4. The sub divisions can be ranked according to the number oftrees per kilometer as follows: sub divisions 7,10,14,1,13,2,5,6,12,11,3,15,8,9 & 4. The subdivisions can be ranked according to the number of species diversity per kilometer asfollows sub divisions 7,13,12,14,'1,5,2,11,15,8,10,6,3,4 and 9. Terminalia Catappa(Kottang), Polyalthya longifolia (Willow) Samanea Saman (paramara), Delonix regia(Maimara), Casia fistula (Ehala) & Plumer.ya spp. ( Araliya) represent 5 or more than 5 %in the sample survey. 56 tree species were identified in the study area.Out of 30 selected street SItes, 7 were identified as sites, which need immediate planting programsand another 17 sites needs planting program. <) street sites need immediate pruning operations asthey have trees with first branching height of less than 2.00 meters, which may interrupt the trafficnow. 6 street sites were identified as site" which need immediate removal and replacementoperauons as they have over-matured trees, which may become hazardous trees if necessary actionsare not taken. Out of 15 sub divisions surveyed, 7 were identified as affected with pest-diseaseattack. Further, some recommendations are Identified as to improve the existing situation of thestreet tree planting in the study area and a draft action plan for 5 years was drawn. Further scientificstudies such as species, which can reduce soi' erosion, pollutants absorbers, etc. are needed forbetter management of urban trees.

Nano-Fe⁰ immobilized onto functionalized biochar gaining excellent stability during sorption and reduction of chloramphenicol via transforming to reusable magnetic composite

© 2017 Elsevier B.V. The widely used nanosized zero-valent iron (nZVI or nFe0) particles and their composite material lose reductive nature during application, and the stability of transformed composite material for repeatable application is not addressed to date. To shed light on this, nZVI was synthesized from scrap material and immobilized on functionalized biochar (fBC) to prepare nZVI-fBC composite. Comparative study between nZVI and nZVI-fBC composite on the removal of chlorinated antibiotic chloramphenicol from different water types was conducted. The results suggested that nZVI was solely responsible for reduction of chloramphenicol. Whereas nZVI-fBC could be applied once, within a few hours, for the reduction of chloramphenico (29–32.5%) and subsequently sorption (67.5–70.5%) by transforming to a fully magnetic composite (nFe3O4-fBC) gaining stability with synergistic sorption performance. In both cases, two reduction by-products were identified namely 2-chloro-N-[1,3-dihydroxy-1-(4-aminophenyl)propan-2-yl]acetamide (m/z 257) and dechlorinated N-[1,3-dihydroxy-1-(4-aminophenyl)propan-2-yl]acetamide (m/z 223). The complete removal of 3.1 µM L−1 of chloramphenicol in different water was faster by nZVI-fBC (∼12–15 h) than by stable nFe3O4-fBC composite (∼18 h). Both nZVI-fBC and nFe3O4-fBC composites removed chloramphenicol in the order: deionized water > lake water > synthetic wastewater. nFe3O4-fBC showed excellent reusability after regeneration, with the regenerated nFe3O4-fBC composite (after 6 cycles of application) showing significant performance for methylene blue removal (∼287 mg g−1). Therefore, the transformed nFe3O4-fBC composite is a promising and reusable sorbent for the efficient removal of organic contaminants

Single and competitive sorption properties and mechanism of functionalized biochar for removing sulfonamide antibiotics from water

© 2016 Elsevier B.V. Single and competitive sorption of ionisable sulphonamides sulfamethazine, sulfamethoxazole and sulfathiazole on functionalized biochar was highly pH dependent. The equilibrium data were well represented by both Langmuir and Freundlich models for single solutes, and by the Langmuir model for competitive solutes. Sorption capacity and distribution coefficient values decreased as sulfathiazole > sulfamethoxazole > sulfamethazine. The sorption capacity of each antibiotic in competitive mode is about three times lower than in single solute sorption. The kinetics data were best described by the pseudo second-order (PSO) model for single solutes, and by PSO and intra-particle diffusion models for competitive solutes. Adsorption mechanism was governed by pore filling through diffusion process. The findings from pH shift, FTIR spectra and Raman band shift showed that sorption of neutral sulfonamide species occurred mainly due to strong H-bonds followed by π+-π electron-donor-acceptor (EDA), and by Lewis acid-base interaction. Moreover, EDA was the main mechanism for the sorption of positive sulfonamides species. The sorption of negative species was mainly regulated by proton exchange with water forming negative charge assisted H-bond (CAHB), followed by the neutralization of –OH groups by H+released from functionalized biochar surface; in addition π-π electron-acceptor-acceptor (EAA) interaction played an important role

Photodegradation of estrogenic endocrine disrupting steroidal hormones in aqueous systems: Progress and future challenges

© 2016 Elsevier B.V. This article reviews different photodegradation technologies used for the removal of four endocrine disrupting chemicals (EDCs): estrone (E1), 17β-estradiol (E2), estriol (E3) and 17α-ethinylestradiol (EE2). The degradation efficiency is greater under UV than visible light; and increases with light intensity up to when mass transfer becomes the rate limiting step. Substantial rates are observed in the environmentally relevant range of pH7-8, though higher rates are obtained for pH above the pKa (~10.4) of the EDCs. The effects of dissolved organic matter (DOM) on EDC photodegradation are complex with both positive and negative impacts being reported. TiO2 remains the best catalyst due to its superior activity, chemical and photo stability, cheap commercial availability, capacity to function at ambient conditions and low toxicity. The optimum TiO2 loading is 0.05-1gl-1, while higher loadings have negative impact on EDC removal. The suspended catalysts prove to be more efficient in photocatalysis compared to the immobilised catalysts, while the latter are considered more suitable for commercial scale applications. Photodegradation mostly follows 1st or pseudo 1st order kinetics. Photodegradation typically eradicates or moderates estrogenic activity, though some intermediates are found to exhibit higher estrogenicity than the parent EDCs; the persistence of estrogenic activity is mainly attributed to the presence of the phenolic moiety in intermediates

Measurements of hydrocortisone and cortisone for longitudinal profiling of equine plasma by liquid chromatography-tandem mass spectrometry.

The conventional detection of exogenous drugs in equine doping samples has been used for confirmation and subsequent prosecution of participants responsible. In recent years, alternative methods using indirect detection have been investigated due to the expanding number of pharmaceutical agents available with the potential of misuse. The monitoring of endogenous biomarkers such as hydrocortisone (HC) has been studied in equine urine with an international threshold of 1 μg/ml established; however, there is no current threshold for equine plasma. The aim of this research was to investigate plasma concentrations of HC and cortisone (C) in race day samples compared to an administration of Triamcinolone Acetonide (TACA). The reference population (n = 1150) provided HC (6 to 145 ng/ml) and C (0.7 to 13 ng/ml) levels to derive the HC to C ratio (HC/C). Population reference limits (PRLs) were proposed for HC/C values at 0.2 (lower) and 61 (upper). Administration of TACA resulted in down-regulation of HC/C values below the estimated PRLs for up to 96 h post-administration. This indirect detection period was longer than the detection of TACA for 72 h. The use of individual reference limits (IRLs) for HC/C values was investigated to support the Equine Biological Passport (EBP), an intelligence model developed by Racing NSW for longitudinal monitoring of biomarkers

Photocatalysis of estrone in water and wastewater: Comparison between Au-TiO<inf>2</inf> nanocomposite and TiO<inf>2</inf>, and degradation by-products

© 2017 Elsevier B.V. Gold-modified TiO2 (Au-TiO2) photocatalysts were utilised for the degradation of estrone (E1), a major endocrine disrupting chemical in water and wastewater. Au-TiO2 catalysts were synthesised by a deposition-precipitation method with gold loadings of 0–8% (wt%). The Au-TiO2 nanocomposite exhibited superior activity compared to P25 TiO2 under UVA (λ = 365 nm), cool white (λ > 420 nm) and green (λ = 523 nm) light emitting diodes (LEDs), for treating 1 mg l− 1 of E1. The 4 wt% Au loading was found to produce the best photocatalytic activity with a rate constant of 2.44 ± 0.36 h− 1, compared to 0.06 ± 0.01 h− 1 for P25 TiO2, under visible light. In total 4 by-products were identified, one from negative ionization mode (m/z = 269) and three from positive ionization mode (m/z = 287) during photocatalysis, which were also degraded with time by Au-TiO2. For different water matrices, the photodegradation rate of E1 decreased in the order: ultrapure water > synthetic wastewater ≈ wastewater effluent from membrane bio-reactor. Overall, 4 wt% Au-TiO2 demonstrated superior performance compared to P25 TiO2 in water and wastewater

Photolytic and photocatalytic degradation of organic UV filters in contaminated water

© 2017 Elsevier B.V. UV filters as emerging contaminants are of great concern and their wide detection in aquatic environments indicates their chemical stability and persistence. This review summarized the photolytic and photocatalytic degradation of UV filters in contaminated water. The findings indicated that limited research has been conducted on the photolysis and photocatalysis of UV filters. Photolysis of UV filters through UV irradiation in natural water was a slow process, which was accelerated by the presence of photosensitisers e.g. triplet state of chromaphoric dissolved organic matter (3CDOM*) and nutrients but reduced by salinity, dissolved organic matter (DOM) and divalent cations. UV Photocatalysis of 4-methylbenzylidene camphor and 2-phenylbenzimidazole-5-sulfonic acid was very effective with 100% removal within 30 min and 90 min using medicated TiO2/H2O2 and TiO2, respectively. The radiation source, type of catalyst and oxygen content were key factors. Future research should focus on improved understanding of photodegradation pathways and by-products of UV filters

Photocatalysis of 17α-ethynylestradiol and estriol in water using engineered immersible optical fibres and light emitting diodes

© 2019 Elsevier Ltd This research aims to promote photocatalysis of endocrine disrupting chemicals (EDCs) in water. Two reactor setups with (i) modified air-clad optical fibres and (ii) waterproof LED strips were utilised to transmit light to photocatalysts P25 TiO2 and gold-modified TiO2 (Au-TiO2). The performances to photodegrade 17α-ethynylestradiol (EE2) and estriol (E3) under Cool White and UVA high efficacy LEDs were examined. Au-TiO2 showed superior photocatalytic activity for EE2 removal over P25 TiO2. The pseudo first-order rate constants for EE2 photocatalysis under UVA were 0.55 h−1 and 0.89 h−1 for TiO2 and Au-TiO2, respectively. E3 was effectively degraded by Au-TiO2 in the immersible LED strip reactor (0.13 h−1)

Chloramphenicol interaction with functionalized biochar in water: sorptive mechanism, molecular imprinting effect and repeatable application

© 2017 Elsevier B.V. Biochar and functionalized biochar (fBC-1 and fBC-2) were prepared and applied to remove antibiotic chloramphenicol from deionized water, lake water and synthetic wastewater. Results showed that chloramphenicol removal on biochar was pH dependent and maximum sorption occurred at pH 4.0–4.5. The sorption data of chloramphenicol fitted better with the Langmuir isotherm model than the Freundlich isotherm model with the maximum Langmuir sorption capacity of 233 μM g− 1 using fBC-2. Chloramphenicol sorption on fBC-2 followed the trend: deionized water > lake water > synthetic wastewater. The presence of humic acid decreased the sorption distribution coefficient (Kd) while the presence of low ionic strength and soil in solution increased Kd value significantly. The mechanism of sorption on fBC mainly involved electron-donor-acceptor (EDA) interactions at pH  7.0. Additionally, solvent and thermal regeneration of fBC-2 for repeatable applications showed excellent sorption of chloramphenicol under the same condition, due to the creation of a molecular imprinting effect in fBC-2. Consequently, fBC-2 can be applied with excellent reusability properties to remove chloramphenicol and other similar organic contaminants