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Photocatalytic membrane reactors (PMRs) are a promising technology for micropollutant removal. Sunlight utilization and catalyst surface sites limit photodegradation. A poly(vinylidene fluoride) (PVDF) nanofiber composite membrane (NCM) with immobilized visible-light-responsive g-C 3 N 4 /Bi 2 MoO 6 (BMCN) were developed. Photodegradation of steroid hormones with the PVDF-BMCN NCM was investigated with varying catalyst properties, operating conditions, and relevant solution chemistry under solar irradiation. Increasing CN ratio (0-65 %) enhanced estradiol (E2) degradation from 20 ± 10 to 75 ± 7 % due to improved sunlight utilization and photon lifetime. PVDF nanofibers reduced self-aggregation of catalysts. Hydraulic residence time and light intensity enhanced the photodegradation. With the increasing pH value, the E2 removal decreased from 84 ± 4 to 67 ± 7 % owing to electrical repulsion and thus reduced adsorption between catalysts and E2. A removal of 96 % can be attained at environmentally relevant feed concentration (100 ng.L -1 ) with a flux of 60 L.m -2 .h -1 , irradiance of 100 mW.cm -2 , and 1 mg.cm -2 BMCN65 loading. This confirmed that heterojunction photocatalysts can enhance micropollutants degradation in PMRs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

3-Nitro-l-tyrosine (3NT) is an oxidative stress metabolite associated with neurodegenerative diseases such as Parkinson's disease and rheumatoid arthritis. In this study, the N, S-co-doped graphene quantum dots (NSGQDs) derived from nitrogen-doped Ti 3 C 2 T x MXene nanosheet via the hydrothermal method in the presence of mercaptosuccinic acid was synthesized as an optical sensing probe to detect 3NT in human serum. Tetramethyl ammonium hydroxide, the nitrogen source and delamination agent, was used to prepare nitrogen-doped MXene nanosheets via one step at room temperature. The as-prepared NSGQDs are uniform with an average size of 1.2 ± 0.6 nm, and can be stable in aqueous solution for at least 90 d to serve as the fluorescence probe. The N atoms in N-MXene reduce the restacking and aggregation of MXene nanosheets, while the sulfur dopant in NSGQDs increases the quantum yield from 6.2 to 12.1 % as well as enhances the selectivity of 3NT over the other 12 interferences via coordination interaction with nitro group in 3NT. A linear range of 0.02-150 μM in PBS and 0.05-200 μM in human serum with a recovery of 97-108 % for 3NT detection is observed. Moreover, the limit of detection can be lowered to 4.2 and 7 nM in PBS and 1 × diluted human serum, respectively. Results obtained clearly indicate the potential application of the N-Ti 3 C 2 T x derived NSGQD for effective detection of 3NT, which can open a window for the synthesis of doped GQDs via 2D MXene materials for ultrasensitive and selective detection of other biometabolites and biomarkers of neurodegenerative diseases in biological fluids., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this work, a NiCo bimetallic ZIF (BMZIF) dodecahedron material has been synthesized by the precipitation approach and then used for simultaneously photoelectrocatalytic degradation of sulfamethoxazole (SMX) and hydrogen production. The combination of Ni/Co loading in ZIF structure increased the specific surface area 1484 (m 2  g -1 ) and photocurrent density (0.4 mA cm -2 ), which can facilitate the good charge transfer efficiency. In presence of peroxymonosulfate (PMS, 0.1 mM), the complete degradation of SMX (10 mg L -1 ) was achieved at initial pH of 7 within 24 min, with the pseudo-first-order rate constants of 0.18 min -1 and TOC removal efficiency of 85 %. Radical scavenger experiments affirm that • OH radicals were the primary oxygen reactive species to drive the SMX degradation. Along with SMX degradation at the anode, the H 2 production was observed at the cathode (140 μmol cm -2  h -1 ), which was 1.5 and 3 times higher than that of Co-ZIF and Ni-ZIF, respectively. The superior catalytic performance of BMZIF was assigned to the distinctive internal structure and synergistic effect between ZIF and Ni/Co bimetals, which improves light absorption and charge conduction efficiency. This study may provide insight into the new way to treat polluted water and simultaneously produce green energy using bimetallic ZIF in a PEC system., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Biochar made from agricultural waste is gaining more attention in energy field due to its sustainability, low cost, apart from having high supercapacitance performance. Also, it has a wide range of environmental applications, including wastewater treatment, upgrading soil fertility, contaminant immobilization, and in situ carbon sequestration. The existing thermo-chemical methodologies for converting agricultural waste into a sustainable material i.e. biochar and the role of activation agents in enhancing the performance of these materials were critically analyzed and discussed. An overview of recent trends in agricultural waste-derived biochar for supercapacitor electrodes is highlighted in this review that emphasizes green circular economy for encouraging net-zero utility of agriculture waste biomass. The roles of various newly prepared "green" electrolytes in reducing the negative consequences of supercapacitor is also reviewed. The trashing of agricultural waste and the depletion of energy supplies has become a global concern, hurting the world's ecosystem and economy through pollution and a fuel crisis and hence the concept of a green circular economic model is also highlighted., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The development of an efficient protein-inorganic nanohybrid with superior nanozyme activity for highly sensitive detection of glutathione (GSH) is essential for early diagnosis of human diseases. Herein, a rapid and highly sensitive colorimetric assay using self-assembled bovine serum albumin-hydrated manganese phosphate nanoflowers (MnPNF) as a biomimic oxidase is developed for GSH detection in human serum. The BSA can complex with Mn 2+ to serve the nucleation center to produce MnPNF in the presence of phosphate-buffered saline (PBS). The morphology and surface characterization results show that the MnPNF is assembled with hierarchical nanoplates to form 500 nm nanoflowers. The oxidase-like activity of MnPNF is based on the redox reaction with 3,3',5,5'-tetramethylbenzidine. However, the addition of GSH can reduce MnPNF to Mn 2+ , and subsequently supresses the oxidase-like activity and a yellow color at 450 nm is observed in the presence of H 2 SO 4 . The MnPNF-based nanozyme exhibits excellent sensing ability toward GSH detection, and a good linear relationship between the change in absorbance at 450 nm and the added amounts of GSH at 50 nM-10 μM with low limits of detection of 20 and 26.6 nM in the PBS and diluted human serum, respectively, is observed. Moreover, the sensing probe shows a superior selectivity over the other 16 interferences, which drive the determination of GSH feasible in real human serum. Since the MnPNF can be simply prepared at room temperature and no functionalization is required, this assay can be used to design the highly efficient biomimic oxidase for effective sensing of GSH and other disease-related biomolecules in biological fluid samples., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A facile impregnation method was used to fabricate a hybrid CoO-3D ordered mesoporous carbon nitride (CoO@mpgCN) catalyst that effectively activated peroxymonosulfate (PMS) for the degradation of pharmaceutical chemical, exemplified by antibiotic sulfamethoxazole (SMX) in aqueous solutions. The CoO@mpgCN/PMS system exhibited high catalytic reactivity and SMX removal efficiency over a wide pH range with an observed rate constant (k obs ) of 0.314 min -1 . Furthermore, CoO@mpgCN was stable with consistently high degree of SMX degradation without having cobalt dissolution and loss of catalytic activity for at least five consecutive cycles. The significant catalysis performance of CoO@mpgCN was due to its uniformly distributed mesopores, large specific surface area, and high electron transfer ability at the active CoO sites. Both quenching experiments and electron paramagnetic resonance (EPR) analysis verified the yield, in abundance, of highly active species, specifically SO 4 - and OH from the CoO@mpgCN activation of PMS, primarily. Hence, SMX degradation followed a radical chain reaction mechanism. The result of this study revealed a novel prospective of CoO@mpgCN composite as PMS activator for the remediation of recalcitrant pollutants in water., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A simple and facile synthesis method is developed for the fabrication of CoO loaded ordered mesoporous carbon nitride (CoO@meso-CN) composites, at various CoO loadings, and used, for the first time, to activate persulfate (PS) for methylene blue (MB) degradation. The interfacial interaction between the ultrafine CoO nanoparticles, immobilized by high surface area, regular mesopores, and graphitic nature of the meso-CN support can further enhance the catalytic activation of PS for methylene blue (MB) degradation. Among all catalysts studied, the 5-wt% CoO@meso-CN exhibits the best catalytic performance with a k obs of 0.264 min -1 . High initial pH, especially at pH-11, is more beneficial for PS activation. Furthermore, the CoO@meso-CN nanocatalyst is highly stable with a consistently high degree of MB degradation and negligible cobalt leaching for at least 5 consecutive catalytic cycles. Both SO 4 - and OH are the major reactive species based on results of EPR and quenching experiments. The degradation intermediates of MB are also identified by HPLC/MS/MS and the possible degradation pathway is proposed. Results clearly demonstrate that CoO@meso-CN is a promising green catalyst with enormous potential for the remediation of hazardous chemicals using PS., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The recycling of the huge amount of thin film transistor liquid crystal display (TFT-LCD) glass wastes has become one of the worldwide environmental issues. Herein, a novel and cost-effective synthesis method for the fabrication of mesoporous aluminosilicate composite (M-ANC) from the TFT-LCD waste has been developed to serve as the environmentally benign adsorbent for the removal of metal ions including Cu 2+ , Zn 2+ and Ni 2+ . After melting at 1000 °C in the presence of Na 2 CO 3 for phase separation, nanoparticles with average particle size of 12 nm appear on the surface of M-ANC, and subsequently results in the production of mesoporous structure with a surface area of 175 m 2  g -1 . The tailored M-ANC shows negatively charged and functional groups, which exhibits an excellent adsorption capacity toward metal ion removal in the pH range of 1.5-7.0. The maximum Langmuir adsorption capacity of Cu 2+ , Zn 2+ and Ni 2+ are determined to be 64.5, 34.0 and 23.1 mg g -1 , respectively, at pH 3.5. Moreover, the environmental applicability of M-ANC is evaluated by column experiment in the presence of real electroplating wastewater. M-ANC can effectively remove Ni 2+ in the electroplating wastewater with the adsorption capacity of 18.7 mg g -1 . Results obtained in this study clearly indicate that M-ANC recycled from TFT-LCD is a novel environmentally friendly adsorbent toward metal ion removal, which can open a gateway to fabricate mesoporous aluminosilicate materials through the recycling of other electronic wastes for real environmental application to remove metal ions and other emerging pollutants in the contaminated water and wastewater., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Conventional photocatalytic nanomaterials are not environmentally sustainable since these are usually produced from scarce mineral and metal precursors. Moreover, high pollutant removal efficiencies by conventional photocatalysts are only attained after several hours of reaction with light. In this study, novel visible light-active photocatalysts were synthesized from environment-friendly carbon precursors and applied for the rapid degradation of sulfamethoxazole (SMX) in aqueous solutions. The photocatalysts were prepared via the co-pyrolysis of urea with varying doping temperature and dopant amount. These variations played a vital role in improving the performance of the photocatalysts and resulted in up to >99% SMX removal within 45 min of visible light irradiation. Characterization of the photocatalysts showed that potassium and iodine dopants were responsible in the red shift and broadening of the light absorption spectrum to the visible region. In addition, the band gap energy narrowed by 0.23 eV resulting in faster charge transfer but slower recombination of the photo-generated electron and hole pairs. Effects of varying concentrations of inorganic salts (NO 3 - , SO 4 2- , Cl - , PO 4 3- ) on SMX removal were also examined. Lastly, the mechanism of SMX photodegradation was elucidated., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A ZnFe 2 O 4 -TiO 2 nanocomposite combining p-type ZnFe 2 O 4 and n-type TiO 2 was successfully fabricated. The ZnFe 2 O 4 -TiO 2 nanocomposite greatly enhanced the bisphenol A (BPA) photodegradation under visible light irradiation at 465 ± 40 nm. Loading TiO 2 with 1 wt% of ZnFe 2 O 4 produced high photocurrent and low charge transfer resistance. The photodegradation rate of BPA by ZnFe 2 O 4 -TiO 2 , which was highly dependent on the water chemistry including pH, anions, and humic acid, was 20.8-21.4 times higher than that of commercial TiO 2 photocatalysts. Chloride and sulfate ions enhanced BPA photodegradation mostly due to the production of more radical species; whereas nitrate, dihydrogen phosphate, and bicarbonate ions decreased the photodegradation rate of BPA due to the scavenge of hydroxyl radicals. The photoactivity and recyclability of ZnFe 2 O 4 -TiO 2 in lake water was also assessed. A near complete BPA removal from lake water was observed under visible light irradiation. Furthermore, >90% of photocatalytic activity toward BPA degradation was achieved in 5 cycles of continuous addition of BPA to the lake water. The BPA degradation intermediates were identified by HPLC/MS/MS and possible reaction pathways were proposed. Results clearly demonstrate the excellent visible-light-sensitive photocatalytic degradation of BPA over ZnFe 2 O 4 -TiO 2 composite which has a great application potential for the decomposition of emerging contaminants in impaired waters., (Copyright © 2018. Published by Elsevier B.V.)

Multifunctional nanocomposites containing intrinsic property for serving as the sensing elements as well as targeted nanoconjugates are highly preferred in various therapeutic applications. In this work, nanocomposites of graphene quantum dots (GQDs) and Fe 3 O 4 with conjugation of lectin protein, concanavalin A, to form GQD-ConA@Fe 3 O 4 nanocomposites are developed for both detection of cancer cell and release of drugs to HeLa cells. The GQD-ConA@Fe 3 O 4 nanocomposites deposited on Pt electrode can detect cancerous HeLa cells over normal endothelial cells with a dynamic linear range of 5 × 10 2 to 1 × 10 5  cells mL -1 with a detection limit of 273 cell mL -1 . The GQD-ConA@Fe 3 O 4 also can serve as nanocarriers for loading and delivering doxorubicin (Dox). The in vitro cell images show that the Dox concentration in HeLa cells is enhanced more than double in the presence of external magnetic field due to the incorporation of Fe 3 O 4 in the nanocarrier. The cytotoxicity assay indicates that the susceptibility of cancerous HeLa cells to Dox is 13% higher than that of normal cells, confirming the selective role of ConA in nanocarriers. Results clearly indicate the GQD-ConA@Fe 3 O 4 nanocomposites as a promising material for cancer cell detection and targeted Dox release toward HeLa cells which can serve as the multifunctional platform for novel cancer cell diagnostic and therapeutic applications., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Environmental applications of nanoparticles (NP) increasingly result in widespread NP distribution within porous media where they are subject to various concurrent transport mechanisms including irreversible deposition, attachment/detachment (equilibrium or kinetic), agglomeration, physical straining, site-blocking, ripening, and size exclusion. Fundamental research in NP transport is typically conducted at small scale, and theoretical mechanistic modeling of particle transport in porous media faces challenges when considering the simultaneous effects of transport mechanisms. Continuum modeling approaches, in contrast, are scalable across various scales ranging from column experiments to aquifer. They have also been able to successfully describe the simultaneous occurrence of various transport mechanisms of NP in porous media such as blocking/straining or agglomeration/deposition/detachment. However, the diversity of model equations developed by different authors and the lack of effective approaches for their validation present obstacles to the successful robust application of these models for describing or predicting NP transport phenomena. This review aims to describe consistently all the important NP transport mechanisms along with their representative mathematical continuum models as found in the current scientific literature. Detailed characterizations of each transport phenomenon in regards to their manifestation in the column experiment outcomes, i.e., breakthrough curve (BTC) and residual concentration profile (RCP), are presented to facilitate future interpretations of BTCs and RCPs. The review highlights two NP transport mechanisms, agglomeration and size exclusion, which are potentially of great importance in controlling the fate and transport of NP in the subsurface media yet have been widely neglected in many existing modeling studies. A critical limitation of the continuum modeling approach is the number of parameters used upon application to larger scales and when a series of transport mechanisms are involved. We investigate the use of simplifying assumptions, such as the equilibrium assumption, in modeling the attachment/detachment mechanisms within a continuum modelling framework. While acknowledging criticisms about the use of this assumption for NP deposition on a mechanistic (process) basis, we found that its use as a description of dynamic deposition behavior in a continuum model yields broadly similar results to those arising from a kinetic model. Furthermore, we show that in two dimensional (2-D) continuum models the modeling efficiency based on the Akaike information criterion (AIC) is enhanced for equilibrium vs kinetic with no significant reduction in model performance. This is because fewer parameters are needed for the equilibrium model compared to the kinetic model. Two major transport regimes are identified in the transport of NP within porous media. The first regime is characterized by higher particle-surface attachment affinity than particle-particle attachment affinity, and operative transport mechanisms of physicochemical filtration, blocking, and physical retention. The second regime is characterized by the domination of particle-particle attachment tendency over particle-surface affinity. In this regime although physicochemical filtration as well as straining may still be operative, ripening is predominant together with agglomeration and further subsequent retention. In both regimes careful assessment of NP fate and transport is necessary since certain combinations of concurrent transport phenomena leading to large migration distances are possible in either case., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this study, a rapid and effective microwave-assisted hydrothermal method was developed for the synthesis of Cu, N-codoped titanate nanotubes (Cu, N-TNTs) to enhance the photocatalytic degradation efficiency and rate of bisphenol A (BPA) under UV and visible light irradiations. The TNTs were first synthesized at 150°C for 3h under microwave heating conditions followed by the calcination at 450°C in the presence of 6wt% Cu ions and N 2 /NH 3 to fabricate Cu, N-TNTs composites. The Cu, N-TNTs exhibited excellent photocatalytic activity toward BPA degradation under UV and visible light irradiations. The X-ray photoelectron spectra indicated that Cu species in Cu, N-TNTs were mainly in zerovalent form and could serve as the electron donors as well as shuttling species to accelerate the photodegradation of BPA. In addition, the nitrogen atoms were incorporated into the anatase lattices to increase the visible-light-responsive capability. The surface normalized reaction rate constants for BPA degradation were 4.3 and 1.5 times higher than those of Degussa P25 TiO 2 under UV and visible light irradiations, respectively. The electron spin resonance spectra showed that Cu, N-codoped TNTs prolonged the generation of oxygen-containing radicals for at least 5min, resulting in the significant enhancement of photodegradation efficiency and rate of BPA. Results obtained in this study open a new avenue by using simple and effective microwave-assisted hydrothermal method to fabricate low dimensional codoped TNTs which can be potentially applied in a wide variety of fields of purification, green chemistry and photocatalysis., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In this study, the microwave-assisted sol-gel method and chemical reduction were used to synthesize Cu-TiO2 nanorod composites for enhanced photocatalytic degradation of bisphenol A (BPA) in the presence of UV and visible lights. The electron microscopic images showed that the Cu nanoparticles at 4.5±0.1nm were well-deposited onto the surface of TiO2 nanorods after chemical reduction of Cu ions by NaBH4. The X-ray diffractometry patterns and X-ray photoelectron spectroscopic results indicated that Cu species on the Cu-TiO2 nanorods were mainly the mixture of Cu2O and Cu(0). The Cu-TiO2 nanorods showed excellent photocatalytic activity toward BPA photodegradation under the irradiation of UV and visible lights. The pseudo-first-order rate constant (kobs) for BPA photodegradation by 7wt% Cu-TiO2 nanorods were 18.4 and 3.8 times higher than those of as-synthesized TiO2 nanorods and Degussa P25 TiO2, respectively, under the UV light irradiation. In addition, the kobs for BPA photodegradation by 7wt% Cu-TiO2 nanorods increased by a factor of 5.8 when compared with that of Degussa P25 TiO2 under the irradiation of 460±40nm visible light. Results obtained in this study clearly demonstrate the feasibility of using one-dimensional Cu-TiO2 nanorods for photocatalytic degradation of BPA and other pharmaceutical and personal care products in water and wastewater treatment plants., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The photoassisted reduction of metal ions and organic dye by metal-deposited Degussa P25 TiO(2) nanoparticles was investigated. Copper and silver ions were selected as the target metal ions to modify the surface properties of TiO(2) and to enhance the photocatalytic activity of TiO(2) towards methylene blue (MB) degradation. X-ray powder diffraction (XRPD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) were used to characterize the crystallinity, chemical species and morphology of metal-deposited TiO(2), respectively. Results showed that the particle size of metal-deposited TiO(2) was larger than that of Degussa P25 TiO(2). Based on XRPD patterns and XPS spectra, it was observed that the addition of formate promoted the photoreduction of metal ion by lowering its oxidation number, and subsequently enhancing the photodegradation efficiency and rate of MB. The pseudo-first-order rate constant (k(obs)) for MB photodegradation by Degussa P25 TiO(2) was 3.94 x 10(-2) min(-1) and increased by 1.4-1.7 times in k(obs) with metal-deposited TiO(2) for MB photodegradation compared to simple Degussa P25 TiO(2). The increase in mass loading of metal ions significantly enhanced the photodegradation efficiency of MB; the k(obs) for MB degradation increased from 3.94 x 10(-2) min(-1) in the absence of metal ion to 4.64-7.28 x 10(-2) min(-1) for Ag/TiO(2) and to 5.14-7.61 x 10(-2) min(-1) for Cu/TiO(2). In addition, the electrons generated from TiO(2) can effectively reduce metal ions and MB simultaneously under anoxic conditions. However, metal ions and organic dye would compete for electrons from the illuminated TiO(2)., (Copyright 2010 Elsevier B.V. All rights reserved.)

The transformation of carbon tetrachloride (CT) by biogenic iron species produced from the bioreduction of various Fe(III) oxides in the presence of Geobacter sulfurreducens and electron shuttles were investigated. Cysteine and anthraquinone-2,6-disulfonate (AQDS) at concentrations of 0.5mM and 10microM, respectively, were added as the electron shuttles. Addition of electron shuttles enhanced the extent of reduction and rate of ferric oxide reduction. The bioreduction extents of ferric oxides by G. sulfurreducens in the presence of electron shuttles were 22.8-48.3% for ferrihydrite, 6.5-17.2% for hematite, and 3.0-11.3% for goethite. After normalization to the surface areas, a higher rate of CT reduction was observed per unit of adsorbed Fe(II) on crystalline oxides. The produced biogenic Fe(II) from crystalline iron oxides was 2.8-7.6 times lower than that obtained from ferrihydrite, while the surface area-normalized rate constant for iron-mediated CT transformation in the presence of goethite and hematite were, by factors of 2-21, higher than that obtained using ferrihydrite. These results clearly depict that G. sulfurreducens drove the reduction of CT primarily through the formation of biogenic iron species in the presence of electron shuttle under iron-reducing conditions and that it is a surface area dependent process.

The objective of this study was to determine the concentrations and possible sources of heavy metals and persistent organic pollutants (POPs) in water and estuarine sediments from Gao-ping River in order to evaluate the environmental quality of aquatic system in southern Taiwan. High concentrations of heavy metals including Cr, Zn, Ni, Cu and As, ranging from 10.7 to 180 mg/kg-dry weight (dw), were detected in sediments from Gao-ping River. When normalized to the principal component analysis (PCA), swinery and electroplating wastewaters were found to be the most important pollution sources for heavy metals. Of various organochlorine pesticide (OCP) residues detected, aldrin and total-hexachlorocyclohexane (HCH) were frequently found in sediments. The total concentrations of OCPs were in the range 0.47-47.4 ng/g-dw. Also, the total-HCH, total-cyclodiene, and total-dichlorodiphenyltrichloroethane (DDT) were in the range 0.37-36.3, 0.21-19.0, and 0.44-1.88 ng/g-dw, respectively. The polychlorinated biphenyl (PCB) concentrations in sediments from Gao-ping River ranged between 0.37 and 5.89 ng/g-dw. The PCB concentrations are positively correlated to the organic contents of the sediment particles. alpha-HCH was found to be the dominant compound of HCH in the sediments, showing that long-range transport may be the possible source for the contamination of HCH in sediments from Gao-ping River. In summary, trace amounts of POPs in estuarine sediments from Gao-ping River were detected, showing that there still exist a wide variety of POP residues in the river sediments in Taiwan. These POP residues may be mainly from long-range transport and weathered agricultural soils, while heavy metal contamination is primarily from the swinery and industrial wastewaters.

An optical array biosensor encapsulated with hydrolase and oxidoreductase using sol-gel immobilization technique has been fabricated for simultaneous analysis and screening of multiple samples to determine the presence of multianalytes which are clinically important in relation to renal failure. Urease and creatinine deiminase were used to detect urea and creatinine, while glucose oxidase and uricase were coimmobilized with horseradish peroxidase to quantify glucose and uric acid. Moreover, the concentrations of analytes in fetal calf serum were measured and quantified using the developed sensing system. The array biosensor showed good specificity for the simultaneous analysis of multiple samples for multianalytes without obvious cross-interference. The analytical ranges of the four analytes were between 0.01 and 10mM with detection limits of 2.5-80 microM. High precision with relative standard deviations of 3.8-9.2% (n=45) was also demonstrated. The reproducibility of array-to-array in 3 consecutive months was 5.4% (n=3). Moreover, the concentrations of analytes in fetal calf serum were 5.9 mM for urea, 0.13 mM for creatinine, 3.3mM for glucose, and 0.15 mM for uric acid, which were in good agreement with results obtained using the traditional spectroscopic methods. These results demonstrate the first use of a sol-gel-derived optical array biosensor for simultaneous analysis of multiple samples for the presence of multiple clinically important renal analytes.

The solubilization and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a soil system amended with different surfactants was examined. Mineralization experiments were conducted with the addition of [14C]pyrene. An inoculum of the PAH-degrading microorganism, Pseudomonas putida, was investigated for its sensitivity towards four non-ionic and one anionic surfactants with different polyoxyethylene (POE) chain lengths. The addition of surfactant was found to enhance the bioavailability of naphthalene, phenanthrene and pyrene with efficiencies ranging from 21.1 to 60.6%, 33.3 to 62.8% and 26.8 to 70.9%, respectively. The enhanced efficiency followed the order of Brij 30, Triton X-100, Tween 80, and Brij 35, which is correlated with the polyoxyethylene chain of the surfactants. Brij 35 and Tween 80 inhibited the growth of P. putida. However, microorganisms can utilize Triton X-100 and Brij 30 as the sole carbon and energy sources at concentrations above CMC values. In the aqueous system without the addition of surfactants, microorganisms could mineralize [14C]pyrene to 14CO(2) which corresponds to 28% of mineralization. The addition of surfactants decreased the mineralization rate of pyrene. Also, the fraction of the micellar-phase pyrene that can be directly biodegraded decreased as the concentration of micelle increases. However, the mineralization rate can be enhanced by the amendment of Brij 30 when soil was applied to the cultures. This suggests that biodegradable surfactants can be applicable for increasing the bioavailability and mineralization of PAHs in soil systems.

The contamination of organochlorine pesticides (OCPs) in sediments from the Wu-Shi River estuary was investigated to evaluate the pollution potentials and distribution of OCPs in central Taiwan. A total of 19 sediment samples were collected at five sampling stations along the River estuary. The concentrations of OCPs were in the range of 0.99-14.5 ng/g-dry weight (dw) for sigmaHCH (alpha-, beta-, gamma-, delta-HCH), 0.46-13.4 ng/g-dw for sigma cyclodiene and 0.53-11.4 ng/g-dw for sigmaDDT (p,p'-DDD, p,p'-DDE, p,p'-DDT). The mean concentrations of sigmaHCH, sigma cyclodiene and sigmaDDT were 3.79, 4.87 and 2.51 ng/g-dw, respectively. The total concentrations of OCPs correspond to 1.73-71.9 microg/g-OC when normalized to TOC contents. Among the organochlorine pesticides, endosulfan sulfate, beta-HCH, and p,p'-DDD were the most dominant compounds in the sediments with the average concentrations of 1.97, 3.43 and 2.08 ng/g, respectively. Also, different contamination patterns among sampling seasons were observed. The measured concentrations of OCPs collected in spring were higher than those in autumn and winter. A linear relationship between sediment characteristics and OCP residues was also demonstrated. The results obtained in this study show that there still exist a variety of organochlorine pesticide residues in the sediments from the near shore of central Taiwan.