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The adsorption of Pb ions, on high-density polyethylene (PE) microplastics (MPs) with the diameter of 48-500 μm, was examined in this study. According to the Langmuir isotherm, MP of the smallest size, 48 μm, had the greatest adsorption capacity of 0.38 μmol g

Bismuth, a heavy metal which is found to be inexpensive and at a reduced cost, is utilized in the synthesis of different nanomaterials with novel structure, remarkable physical and chemical properties, adjustable bandgap, notable efficiency for photothermal conversion. These characteristics have made this element desirable for various applications such as storage and conversion of energy, electronics, sensors, photocatalysis, and other biomedical applications. These review papers are the vital points for the students, this report guides them to the research papers which focus on the impressive development in the area of bismuth and similar nanostructures. The purpose of the present review is to discuss the various synthesis routes of bismuth-based nanomaterials along with green synthesis, different nanostructures of bismuth, their significant properties, diverse applications and directions for the upcoming research. Therefore, with these different tuneable synthesis methods of bismuth-based nanomaterials combined with their novel properties, would elucidate on the future devices based on various nanostructures of bismuth.

Phthalate esters (PAEs) are fat soluble synthetic chemicals, usually regarded as plasticizers for being added in numerous plastic products. Thus, environmental and health hazards of PAEs are associated with increasing plastic pollution. In this study, PAEs from sludge samples collected from water, sewage, and industrial treatment plants (N = 17) were analyzed using Gas Chromatography/Mass Spectrometry. Microplastics (MPs) were also quantified and correlated with PAEs. Results showed the highest average PAE concentrations in sewage treatment plants. The greatest ΣPAEs concentration were found in sewage treatment plant (STP4) with 32,414 μg/kg dw, while the lowest found in water treatment plant (WTP3) with 2062 μg/kg dw. Among different PAEs, di-(2-ethyl hexyl) phthalate (DEHP) contributes the highest. Similarly, DEHP, di-n-octyl phthalate (DnOP) and diisononyl phthalate (DiNP) significantly correlated with the total PAEs indicating their large contribution to sludge contamination. The abundance of microplastics in sludge ranged between 1 and 7 MP/g, highest at ITP6, but not detected in some stations. While microplastics may potentially increase PAEs, there was no significant relationship between ΣPAEs and MP abundance. The estimated human daily intake of DEHP and di-n-butyl phthalate (DnBP) when contaminated sludge be used showed low toxicological risks to exposed adults. This research presents the sludge characteristics, PAEs, and microplastic concentrations in different wastewater treatment plants in Taiwan. PAE contamination was highly contributed by domestic and industrial wastes shown by their significant amounts in STP and ITP. Results further provide evidence for potential sludge recycling (WTP sludge) and application to soil.

Phthalate esters (PAEs) have known widely being used in plastic products leading to being ubiquitous in the environment by easy to release from those products. This study aims to understand the impact of heavy rainfall on the concentration of PAEs in surface sediments of the Salt River in Kaohsiung, Taiwan, and its potential ecological risks on aquatic organisms. The potential ecological risk assessment of sediment PAEs is based on the total risk quotient (TRQ) method. The total concentration of 10 PAEs (∑PAE10) in sediments of the Salt River is 333-13,615 ng/g dw, with an average of 4212 ± 3753 ng/g dw. Before the rainy season, the ∑PAE10 concentration in sediments at the outlets of domestic sewage in upstream was 9768-13,615 ng/g dw, which were relatively higher than other sites (542-3721 ng/g dw). During the rainy season, the ∑PAE10 concentration was 2820-12,041 ng/g dw, which was 1-11 times higher than that determined before the rainy season. After the rainy season, the ∑PAE10 concentration recorded was 530-6652 ng/g dw, which is 1-11 times lower than the value obtained during the rainy season. PAEs in sediments of the Salt River may have low to moderate potential risks to algae, crustaceans, and fish. Bis(2-ethylhexyl) phthalate (DEHP) and diisobutyl phthalate (DiBP) are the main PAE that poses a potential risk to algae and crustaceans, and to fish respectively, whose values of risk quotient accounts for 40-69% of the TRQ value. The distribution of TRQ values for these aquatic organisms show a decreasing trend of PAEs level with respect to the rainy season: during the rainy season after the rainy season before the rainy season. Heavy rainfall may cause more serious pollution in sediments and increase the exposure risk of PAEs to aquatic organisms.

In this study, biochar derived from spent coffee grounds (SCGB) was used to adsorb norfloxacin (NOR) in water. The biochar properties were interpreted by analysis of the specific surface area, morphology, structure, thermal stability, and functional groups. The impacts of pH, NOR, and ion's present on SCGB performance were examined. The NOR adsorption mode of SCGB is best suited to the Langmuir model (R2 = 0.974) with maximum absorption capacity (69.8 mg g−1). By using a Response Surface Method (RSM), optimal adsorption was also found at pH of 6.26, NOR of 24.69 mg L−1, and SCGB of 1.32 g L−1. Compared with biochars derived from agriculture such as corn stalks, willow branches, potato stem, reed stalks, cauliflower roots, wheat straw, the NOR adsorption capacity of SCGB was 2–30 times higher, but less than 3–4 times for biochars made from Salix mongolica, luffa sponge and polydopamine microspheres. These findings reveal that spent coffee grounds biochar could effectively remove NOR from aqueous solutions. Approaching biochar derived from coffee grounds would be a promising eco-friendly solution because it utilizes solid waste, saves costs, and creates adsorbents to deal with emerging pollutants like antibiotics.

The present report investigates the various MoO

Although the pollution of coral reefs by microplastics (MPs) is an environmental problem of global significance, the effects of MP concentration on scleractinian corals remain largely underexplored. Herein, we exposed a representative scleractinian coral (Goniopora columna) to different concentrations (5-300 mg L

Dyes are hazardous compounds commonly found in industrial wastewaters. Efficient and inexpensive removal of dye molecules from the water matrix has been demonstrated by adsorption processes. Magnetic nano-adsorbents, such as metal ferrites, can be efficiently recovered from the reaction mixture after treating the pollutant. Herein, MFe2O4@GO (M = Cu, Co or Ni) was synthesized via solution combustion method for the removal of dye molecules from aqueous solutions. The characteristics of the MFe2O4@GO, including surface area and pore diameter, surface functional groups, and elemental composition, were examined. Methylene blue was used as representative dye pollutant. Batch adsorption results conformed to the Langmuir isotherm. Maximum adsorption capacities of the MFe2O4@GO (M = Cu, Co or Ni) were 25.81, 50.15 and 76.34 mg g−1, respectively. Kinetics of methylene blue adsorption fitted the pseudo-second-order model. Overall, NiFe2O4@GO exhibited the highest adsorbent performance among the graphene-metal ferrites investigated, primarily because of its high specific surface area and presence of mesopores.

Contamination by microplastics (MPs) and the associated organic pollutants has caused potential threats to the ecological environment of global waters. In this study, MPs were sampled by trawling from the surface waters of the estuary, fishing port entrance and harbor entrance areas connected to the southwestern coast of Taiwan. Moreover, the abundance, morphological characteristics, composition, and associated polycyclic aromatic hydrocarbons (PAHs) of MPs were analyzed. The abundance of MPs was 0.36 ± 0.21 items/m3, which was 6.4 ± 10.7% of the abundance of zooplanktons. The average abundance of MPs was the highest in the estuary area, indicating that river transport was the primary way for MPs to enter the ocean. The most dominant MPs were small (0.33–2 mm; 78.8 ± 8.1%), colored (60.0 ± 12.8%), fragments (66.1 ± 10.6%), comprising PE (52.6 ± 7.6%), and PP (38.7 ± 9.4%). The decomposition of various plastic products and disposable plastic packaging may be the most significant source. The total concentration of PAHs in MPs ranged from 104 to 3595 ng/g dw, with an average of 818 ± 874 ng/g dw. The diagnostic ratios and the results of principal component analysis (PCA) and multiple linear regression of the absolute principal component scores (MLR-APCS) indicated that the PAHs were mainly contributed from sources related to petrogenic (71.4%) and vehicles (28.6%). Most likely due to MPs on the sea surface coming into contact with floating oil spills from ships or floating tar particles.

Shellfishes can easily accumulate metals via water and sediment and which may pose a human health risk by consumption. This study assessed the distribution of metals, including Cd, Cr, Cu, Pb, Ni, Zn, and Hg, in soft tissues of hard clam (Meretrix lusoria), surrounding water body, and sediment in the southwest coast of Taiwan. Hard clams contained the relatively higher concentration of the essential element, such as Zn, Cu, and Ni, and the metal concentration from high to low was Zn > Cu > Ni > Cd > Cr > Pb > Hg. However, the metal concentrations found in hard clam all were lower than the Sanitation Standard for Aquatic Animal of Taiwan. Results of bioaccumulation factors indicated that hard clam shows the ability of metal accumulation from water was higher than that from sediment. Moreover, the metal concentrations in hard clam were negatively correlated with body size except for Hg, which could be presented by the significant power function. Generally, hard clams from the aquaculture pond located on the southwest coast of Taiwan would not be harmful to adult consumers, except for people that consume shellfish more than 100 g. Besides strengthening the management of seafood safety and aquaculture, adjusting the eating and purchasing habits of the consumer could be a practical and feasible way for decreasing health risks. These results can assist the government in determining seafood safety and its implementation in Taiwan.

4-Nonylphenol (4-NP), a phenolic endocrine disruptor chemical (EDC), is known to have high toxicity to aquatic organisms and humans. The remediation of 4-NP-contaminated marine sediments was studied using red algae-based biochar (RAB) thermochemically synthesized from Agardhiella subulata with simple pyrolysis process under different temperatures of 300–900 °C in CO2 atmosphere. The RAB was characterized by XRD, Raman, FTIR spectroscopy, and zeta potential measurements. The calcium in RAB efficiently activated sodium percarbonate (SPC) to generate reactive radicals for the catalytic degradation of 4-NP at pH 9.0. The oxygen-containing functional groups reacted with H2O2, which increased the generation of reactive radicals under alkaline pH condition. Ca2+ ion was the active species responsible for 4-NP degradation. CaO/CaCO3 on RAB surface enhanced direct electron transfer, increased HO production, and 4-NP degradation in marine sediments. Langmuir‒Hinshelwood type kinetics well described the 4-NP degradation process. Remediation of contaminated sediments using RAB could be a sustainable approach toward closed-loop biomass cycling in the degradation of 4-NP contaminants.

Biohydrogen and biosyngas are among the sustainable bioenergy products from biomass resources through gasification. Microwave-assisted gasification (MAG) is still a novel technology, but it is definitely a promising conversion technology to achieve a sustainable bioeconomy. Although this technology shows a massive potential to be fully implemented in the near future, the selectivity and efficiency of biohydrogen and syngas production still need enhancements and further research to secure a cost-effective and energy-efficient industrialization. This article comprehensively reviews the regular, microwave-induced plasma, and catalytic MAG systems in relation to their biohydrogen and biosyngas production, carbon conversion efficiency, and tar removal while discussing the significance of optimal operating conditions and considerations in the gasification system design. Several perspectives such as benefits, challenges, numerical simulations, and scalable opportunities are also explored to provide factual insights for further research and industrial application.

The present report investigates the various MoO3 morphologies prepared via different approaches such as morphologies are cubic sheet, ribbon, and hexagonal sheet. These prepared nanostructures are modified as a MoO3/Ni–F electrode used to detect hydrogen peroxide (H2O2). The influence of the morphology on the microstructural, morphological, electronic state, optical and electrochemical properties of MoO3 nanostructures are systematically studied. The recorded XRD spectra confirmed that the good crystalline nature with the orthorhombic crystal structure. The FESEM analysis shows that preparation approaches strongly influenced the MoO3 morphology. The elemental mapping and XPS analysis confirm the formation of MoO3. The obtained optical band gap values show that the MoO3 morphology-based bandgap values are 3.38, 3.17, and 2.94 eV. The modified MoO3/Ni–F electrode electrochemical impedance spectra show the CP-MoO3 has good conductivity. Moreover, the CP-MoO3/Ni–F electrode has a wide detection window, long-term stability, reproducibility, and a low detection limit is 1.2 μM. Hence, the CP-MoO3/Ni–F electrode electrochemical results suggest that the modified electrode has offered a good matrix for toxic contaminants sensing applications.

The Love River and Ho-Jin River, two major urban rivers in Kaohsiung City, Taiwan, are moderately to heavily polluted because different types of improperly treated wastewaters are discharged into the rivers. In this study, sediment and river water samples were collected from two rivers to investigate the river water quality and accumulation of polycyclic aromatic hydrocarbons (PAHs) in sediments. The spatial distribution, composition, and source appointment of PAHs of the sediments were examined. The impacts of PAHs on ecological system were assessed using toxic equivalence quotient (TEQ) of potentially carcinogenic PAHs (TEQcarc) and sediment quality guidelines. The average PAHs concentrations ranged from 2161 ng/g in Love River sediment to 160 ng/g in Ho-Jin River sediment. This could be due to the fact that Love River Basin had much higher population density and pyrolytic activities. High-ring PAHs (4-6 rings) contributed to 59-90% of the total PAHs concentrations. Benzo(a)pyrene (BaP) had the highest toxic equivalence quotient (up to 188 ng TEQ/g). Moreover, the downstream sediments contained higher TEQ of total TPHs than midstream and upstream sediment samples. The PAHs were adsorbed onto the fine particles with high organic content. Results from diagnostic ratio analyses indicate that the PAHs in two urban river sediments might originate from oil/coal combustion, traffic-related emissions, and waste combustion (pyrogenic activities). Future pollution prevention and management should target the various industries, incinerators, and transportation emission in this region to reduce the PAHs pollution.

Kaohsiung Ocean Dredged Material Disposal Site (KODMDS) that located in the southwest offshore of Taiwan, has been annually disposed about 500,000 ton dredged sediments of Kaohsiung Harbor from 2003 to 2012. Five sediment cores collected from KODMDS and three from nearby reference sites were analyzed to evaluate their sedimentation rates, vertical profiles of heavy metal, and heavy metal pollution indices to assess the impact of dumping harbor dredged sediments into the ocean on the sediment quality in KODMDS. The sedimentation rate of 0.24 cm/y was estimated by the 210 Pb method, which means that the effected depth of the top layer of a core of D1 was affected in the period of dumping dredging sediments. The vertical distribution of heavy metals in the sediment cores from KODMDS showed the concentrations of most heavy metals were slightly elevated in the top layers of the sediment cores, which may be affected by the dumping of harbor dredged sediments. According to the analyzed results of the heavy metal pollution indices, the level of heavy metal pollution, the potential eco-toxicity and the potential ecological risk of the sediments in KODMDS exhibited only a slight increase, which indicated that the increase in concentration of heavy metals may potentially pose the insignificant impact on benthos inhabiting the disposal site.

Six sediment cores collected at the Kaohsiung Harbor of Taiwan were analyzed to evaluate their vertical profiles, enrichments, accumulations, and source apportionments of heavy metals. This was performed to investigate any potential ecological risks posed by heavy metals. Results indicated that the mean heavy metal content (mg kg−1) in the six sediment cores was as follows: Hg (0.4–6.4), Cd (

The characteristics of nanoparticles (NPs) uptake may fundamentally alter physicochemical effects of engineered NPs on aquatic organisms, thereby yielding different ecotoxicology assessment results. The adsorption behavior of nano-TiO2 (P-25) on zebrafish embryos in Holtfreter's medium (pH 7.2, I ∼ 7.2 × 10(-2) M) and the presence of sodium alginate (100 mg/L) as dispersant was investigated. Zebrafish embryos (total 100) were exposed to nano-TiO2 at different concentrations (e.g., 0, 10, 20, 60, 120 mg/L) in batch-mode assay. The adsorption capacity of nano-TiO2 on fish eggs was determined by measuring the Ti concentration on the egg surface using ICP-OES analysis. Results showed that the adsorption capacity increased rapidly in the first hour, and then declined to reach equilibrium in 8 h. The adsorption characteristics was visualized as a three-step process of rapid initial layer formation, followed by break-up of aggregates and finally rearrangement of floc structures; the maximum adsorption capacity was the sum of an inner rigid layers of aggregates of 0.81-0.84 μg-TiO2/#-egg and an outer softly flocculated layers of 1.01 μg-TiO2/#-egg. The Gibbs free energy was 543.29-551.26 and 100.75 kJ/mol, respectively, for the inner-layer and the outer-layer aggregates. Adsorption capacity at 0.5-1.0 μg-TiO2/#-egg promoted egg hatching; but hatching was inhibited at higher adsorption capacity. Results clearly showed that the configuration of TiO2 aggregates could impact the hatching efficiency of zebrafish embryos.

Various chemical oxidation techniques, such as potassium permanganate (KMnO4), sodium persulfate (Na2S2O8), Fenton (H2O2/Fe(2+)), and the modified persulfate and Fenton reagents (activated by ferrous complexes), were carried out to treat marine sediments that were contaminated with polycyclic aromatic hydrocarbons (PAHs) and dredged from Kaohsiung Harbor in Taiwan. Experimental results revealed that KMnO4 was the most effective of the tested oxidants in PAH degradation. Owing to the high organic matter content in the sediment that reduced the efficiencies of Na2S2O8 and regular Fenton reactions, a large excess of oxidant was required. Nevertheless, KH2PO4, Na4P2O7 and four chelating agents (EDTA, sodium citrate, oxalic acid, and sodium oxalate) were utilized to stabilize Fe(II) in activating the Na2S2O8 and Fenton oxidations, while Fe(II)-citrate remarkably promoted the PAH degradation. Increasing the molecular weight and number of rings of PAH did not affect the overall removal efficiencies. The correlation between the effectiveness of the oxidation processes and the physicochemical properties of individual PAH was statistically analyzed. The data implied that the reactivity of PAH (electron affinity and ionization potential) affected its treatability more than did its hydrophobicity (Kow, Koc and Sw), particularly using experimental conditions under which PAHs could be effectively oxidized.

Various surfactants, such as nonionic Triton X-100 and Simple Green™ (SG), and anionic sodium dodecylsulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) were utilized to remove polycyclic aromatic hydrocarbons (PAHs) from heavily contaminated harbor sediments dredged from Kaohsiung Harbor in Taiwan. Desorption/re-sorption equilibrium, kinetics, and washability of PAHs using the selected surfactant were evaluated under different critical micelle concentrations (CMC). Experimental results revealed that the desorption rate of high molecular weight PAHs was greater than those of low molecular weight PAHs, and the anionic SDS was relatively effective in the removal of total PAHs (>50%) compared to the other surfactants. The correlation between the effectiveness of the surfactant washing processes and the physicochemical properties of individual PAH was statistically analyzed. The resulting data suggested that hydrophobic factors (Kow, Koc and Sw) affected PAH treatability more than the reactivity of PAH (electron affinity and ionization potential). Since the adsorption of anionic surfactant altered the hydrophobicity of organic matter in the sediment, PAHs preferred transferring from the sediment to the hydrophobic core of micelles in aqueous solution. Nevertheless, the nonionic surfactant enhanced the PAH partition in the aqueous phase, thus increasing the micellar solubilization of PAH.

We used discarded oyster shells to prepare vaterite calcium carbonate microparticles and explored the removal effects and the underlying mechanism toward several heavy metal ions. The removal efficiency for each ion type was: Pb2+ (99.9%), Cr3+ (99.5%), Fe3+ (99.3%), and Cu2+ (57.1%). With the exception of Cu2+, vaterite calcium carbonate particles exhibited excellent removal performance on all tested heavy metal ions, with exceptional results for Pb2+. The factor affecting the removal efficiency of heavy metal ions is shown to involve an ion exchange reaction between calcium and the heavy metal ions resulting in recrystallization. Vaterite calcium carbonate particles prepared by this method have the advantage of low price, easy synthesis, and reduction of environmental waste. Thus, this procedure for synthesizing vaterite CaCO3 provides an environmentally responsible method for preparing materials that can be economically incorporated into common consumer products such as household drinking water filtration systems.

Due to its toxicity and persistence, pesticide pollution poses a serious threat to human health and the environment. Imidacloprid or IMD is an archetypal neonicotinoid insecticide commonly used to protect a variety of crops worldwide. The present study examines the applicability of two numerical tools -- artificial neural network (ANN) and response surface methodology – Box Behnken design (RSM-BBD) -- to model and optimize oxidative IMD degradation by sodium percarbonate (SPC). The influences of SPC dose, Fe2+ catalyst dosage, and solution pH on IMD removal were evaluated. An ANN composed of an input layer with three neurons, a hidden layer with eight optimum neurons, and an output layer with one neuron was developed to map the complex non-linear process at different levels. Seventeen designed runs of different experimental conditions were derived from RSM-BBD. These experimental conditions and their response values showed to be best fitted in a reduced cubic model equation. Sensitivity analyses revealed the relative importance of the various components: Fe2+ (40.4%) > pH (31.1%) > SPC dose (28.5%). The two model were highly predictive with overall coefficients of determination and root-mean-square errors of 0.9983 and 0.31 for ANN, while 0.9996 and 0.20 for RSM-BBD. Overall, the present study established ANN and RSM-BBD as valuable and effective tools for catalytic SPC oxidation of IMD contaminants. SPC is a cleaner alternative to other oxidants for pesticide degradation as it is non-toxic, safe to handle, and produces by-products that inherently exist in the natural water matrix.

Activated carbon (AC), prepared from dried loofah sponge, was supported on nickel foam to fabricate AC/Ni electrodes. The characteristics of ammonium electrosorption on AC/Ni electrodes was studied. Results showed that AC prepared in one-step activation (without pre-pyrolysis), i.e., OAC, had relatively low crystallinity, high mesoporosity, and high specific capacitance compared to those made in two-step carbonation followed by activation. Adsorption and desorption density of NH4+ were measured at constant potential of −1.0 V (vs. Hg/HgO) and +0.1 V (vs. Hg/HgO), respectively. Non-faradaic charging contributed to the electrochemical storage and adsorption of ammonium ions on the AC surface with a maximal charge efficiency of 80%, at an applied potential of −1.0 V (vs. Hg/HgO). Multiple-layer adsorption isotherm better described the electrosorption of ammonium ion on OAC/Ni electrodes yielding a maximum adsorption capacity of 6 mg-N g−1, which was comparable with other similar systems. Overall, results clearly demonstrated the effect of synthesis strategy on the capacitive charging behaviors of AC/Ni electrodes and its relationship to NH4+ electrosorption.

The accumulation of halogenated organic contaminants in estuaries near harbor areas has been receiving increasing attention. This work demonstrates the reductive treatment of trichloroethene (TCE) within seawater and freshwater using a polymeric surfactant (polyvinyl alcohol-co-vinyl acetate-coitaconic acid) modified nanoscale zero-valent iron (GnZVI). Experimental parameters included the ratio of seawater to freshwater, reaction pH, dosage of GnZVI and initial TCE concentration. It was found that the rate of TCE reduction decreased with increasing weight ratio of seawater to freshwater (ka = 0.075 min−1 in freshwater and 0.01 min−1 in seawater); however, the rate substantially improved by increasing the dosage of GnZVI. A consecutive reaction model of adsorption/desorption and reductive dechlorination was established to assess the chemical kinetics of TCE and the intermediates over the GnZVI. The experimental results suggested that both the amount of free sites on the reductant and reactivity of iron to TCE dominated the degradation efficiency. Desorption was a rate-limiting step for the intermediates that evolved (DCE, VC and ethene) in the bulk solution. Under conditions: GnZVI = 5 g/L, reaction pH around 8 and initial TCE = 10 mg/L, the removal efficiency attained 95%, while the decline in the removal rate of TCE from the seawater could be simply improved by increasing GnZVI dosage (10 g/L). As a role of electron donor for water and TCE, ZVI might passivate with contact time, leading to formation of the main crystalline phase magnetite (Fe3O4) by the coprecipitation of oxidized iron (Fe(II)/Fe(III)) over the surfaces of ZVI particles.

The 4-nonylphenol (4-NP) and 4-tert-octylphenol (4-t-OP) were investigated in the surface sediments of Kaohsiung Harbor, Taiwan. The concentrations were between 18 and 27 882 ng g−1 dw (average 101 ± 3580 ng g−1 dw) and 1.1 and 1150 ng g−1 dw (average 44 ± 174 ng g−1 dw) for 4-NP and 4-t-OP, respectively. The concentrations of 4-NP and 4-t-OP in the river mouths’ sediments are apparently higher and gradually decrease nearer the Harbor. The results showed that the river mouths’ alkylphenol (AP) concentration in the wet season was higher than that in the dry season; in the channels and Harbor entrances, the AP values in the dry season were similar or even higher than those in the wet season. The correlation analysis indicated that total organic carbon (TOC) and organic matter (OM) played an important role in controlling the concentration level of 4-NP and 4-t-OP in the sediments. However, in the pollution hotspot, the direct inflow of pollutants would be the crucial factor that determines the concentration and distribution of organic pollutants in sediments. According to the evaluation of the potential ecological risk, the 4-NP concentration in the harbor had an 87% probability of exceed PNEC (39 ng g−1, predicted no effect concentration) which means that the sediments of Kaohsiung Harbor probably pose a potential ecological risk to aquatic life, as is especially the case with those in the river mouths with relatively high EEQ values (estrogen equivalent concentration).

The distribution, enrichment, and accumulation of heavy metals in the sediments, especially those at the vicinity of tributary estuaries of Kaohsiung Harbor, Taiwan were investigated. Sediment samples from six locations in the Kaohsiung Harbor were collected quarterly in the period from 2002 to 2005 and characterized for metal content (e.g., Hg, Pb, Cd, Cr, Cu, Zn and Al), water content, organic matter, total nitrogen, total phosphorous, total grease, and grain size. Results showed that metal concentrations varied from 0.58 mg kg(-1) for Cd to 596 mg kg(-1) for Zn. Metal concentrations at the vicinity of river mouths were higher than those at other locations. All heavy metals studied, except Cr, had relatively high enrichment factors and geo-accumulation indices in the estuaries. Moreover, metal concentrations correlated closely to the physical-chemical properties of the sediments, which strongly suggested the influence of industrial and municipal wastewaters discharged from the neighboring industrial parks and river basins. Results would help develop strategies for pollution control and sediment remediation of Kaohsiung Harbor.

The Cheng-Ching Lake Water Treatment Plant (CCLWTP) is the main supplier of domestic water for the Greater Kaohsiung area, the second largest metropolis in Taiwan. Biological activated carbon (BAC) filtration is one of the major treatment processes in CCLWTP. The objectives of this study were to evaluate the effectiveness of BAC filtration on water treatment in the studied advanced water treatment plant and its capability on pollutants [e.g., AOC (assimilable organic carbon), bromide, bromate, iron] removal. In this study, water samples from each treatment process of CCLWTP were collected and analyzed periodically to assess the variations in concentrations of AOC and other water quality indicators after each treatment unit. Moreover, the efficiency of biofiltration process using granular activated carbon (GAC) and anthracite as the fillers was also evaluated through a column experiment. Results show that the removal efficiencies for AOC, bromide, bromate, and iron are 86% 100%, 17%, and 30% after the BAC filter bed, respectively. This indicates that BAC filtration plays an important role in pollutant removal. Results also show that AOC concentrations in raw water and effluent of the CCLWTP are approximately 143 and 16 microg acetate-Cl(-1), respectively. This reveals that the treatment processes applied in CCLWTP is able to remove AOC effectively. Results of column study show that the AOC removal efficiencies in the GAC and anthracite columns are 60% and 17%, respectively. Microbial colonization on GAC and anthracite were detected via the observation of scanning electron microscopic images. The observed microorganisms included bacteria (rods, cocci, and filamentous bacteria), fungi, and protozoa. Results from this study provide us insight into the mechanisms of AOC removal by advanced water treatment processes. These findings would be helpful in designing a modified water treatment system for AOC removal and water quality improvement.