Cheng Di Dong

Evaluation of Sediment Toxicity in Kaohsiung Harbor, Taiwan

The contamination and toxicity levels of sediments in Kaohsiung Harbor, Taiwan, were evaluated using different sediment quality guidelines (SQGs). Twenty dredged sediment samples were collected from various locations in the harbor. Distribution of polycyclic aromatic hydrocarbons (PAHs), heavy metals, nutrients, and total organic carbons in the sediment samples were investigated. Results from the sediment analyses show that the sediments contained significant amounts of organics, nutrients, metals, and PAHs. Based on the analyses using the SQGs, sediments dredged from Kaohsiung Harbor were moderately contaminated and most samples have a low and medium-low probability of toxicity pollution. Results show that industrial activities and urban sewage effluents are the major sources of contamination in the harbor sediments.

Evaluation of Cadmium Contamination in the Sediments of Northern Kaohsiung Harbor, Taiwan

The distribution, enrichment, accumulation, and potential ecological risk of Cadmium (Cd) in the surface sediments of northern Kaohsiung Harbor, Taiwan were investigated. Sediment samples from 12 locations of Kaohsiung Harbor were collected and characterized for Cd, aluminum, water content, organic matter, total nitrogen, total phosphorous, total grease, and grain size. Results showed that the Cd concentrations varied from 0.25–2.28 mg/kg with an average of 0.58±0.58 mg/kg. The spatial distribution of Cd reveals that the Cd concentration is relatively high in the river mouth region, and gradually diminishes toward the harbor entrance region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of Cd pollution. Results from the enrichment factor and geo-accumulation index analyses imply that the sediments collected from the river mouth can be characterized between moderate and severe degree enrichment and between moderate and moderate to strong accumulation of Cd, respectively. Results of potential ecological risk index indicate that the sediment has higher to high ecological potential risk. Therefore, a strategy for effective controlling and managing river upstream pollution needs to be immediately implemented in order to improve the sediment quality and alleviate the ecological risk.

Evaluation of Mercury Contamination in Surface Sediments of Southern Kaohsiung Harbor, Taiwan

Total mercury (T-Hg) concentration was determined to evaluation the distribution, enrichment, accumulation and potential ecological risk of mercury contamination in the surface sediments of southern Kaohsiung Harbor, Taiwan. Sediment samples from 12 locations located between the river mouths (i.e., Jen-Gen River and Salt River) and harbor entrance of southern Kaohsiung Harbor were collected and characterized for T-Hg, aluminum, water content, organic matter, and grain size. Results showed that the T-Hg concentrations varied from 0.190.45 mg/kg with an average of 0.28±0.09 mg/kg. The spatial distribution of T-Hg reveals is relatively high in the river mouth region, and gradually diminishes toward the harbor entrance region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of Hg pollution; and Hg may drift with sea current to be dispersed into open sea. Results from the enrichment factor (EF) and geo-accumulation index (Igeo) analyses imply that the sediments can be characterized between moderate and moderately severe degree enrichment and between none to medium and moderate accumulation of Hg, respectively. Results of potential ecological risk index indicate that the sediment has higher to high ecological potential risk.

Evaluation of Zinc Contamination in the Sediments of Salt River Mouth, Taiwan

The distribution, enrichment, and accumulation of Zinc (Zn) in the surface sediments of Salt River mouth, Taiwan, were studied. Results show that samples collected from nine stations near the mouth of Salt River contain 440–1,820 mg/kg of Zn with average of 951±811 mg/kg. The spatial distribution of Zn reveals is relatively high in the river mouth region, and gradually diminishes toward the harbor region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of pollution. Enrichment factor analysis indicates that the sediments of Salt River mouth were moderately severe enrichment with Zn. Geo-accumulation index analysis indicates that the sediments of Salt River mouth were strongly accumulated with Zn. Base on the comparison with sediment quality guidelines (SQGs), the concentrations of Zn in the sediments of Salt River mouth may cause acute biological damage.

Cadmium Contamination in the Sediments of Love River Mouth, Taiwan

Major objectives of this study are to evaluation the enrichment, accumulation, and potential ecological risk of cadmium (Cd) in the sediments of Love River mouth, Taiwan. Ten monitoring stations were installed near the mouth of Love River to collect sediment samples for analyzing Cd. Results of laboratory analyses show that contents of Cd in the sediments are between 0.27 and 1.25 mg/kg with an average of 0.74±0.33 mg/kg. The spatial distribution of Cd reveals that the Cd concentration is relatively high near the boundary of the river mouth, and gradually diminishes toward the harbor region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of pollution. Results from the enrichment factor analysis imply that the sediments can be characterized as minor to severe degree of Cd enrichment. Results of geo-accumulation index analysis indicate that the sediments can be characterized as none to moderately strong degree of Cd accumulation. Results of potential ecological risk index indicate that the sediments at Love River mouth has moderate to high ecological potential risk.

Evaluation of Chromium Contamination in the Surface Sediments of Canon River Estuary, Taiwan

This study was conducted using the data collected at the Canon River estuary, Taiwan to investigate and analyze Chromium (Cr) contained in the sediments, and to evaluate the enrichment and accumulation of Cr. Results of laboratory analyses show that concentrations of Cr in the sediments are between 27 and 192 mg/kg with an average of 111±52 mg/kg. The spatial distribution of Cr reveals is relatively high in the boundary of the river estuary region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of pollution. Results from the enrichment factor and geo-accumulation index analyses imply that the sediments collected from the river estuary can be characterized between no enrichment to moderate degree enrichment and between none to medium accumulation of Cr, respectively. Base on the comparison with sediment quality guidelines, the sediments Cr concentrations may cause acute biological damage. The results can provide regulatory valuable information to be referenced for developing future strategies to renovate and manage river estuary and harbor.

Cu-ACF Composite Catalyst: Synthesis, Characterization, and Electrocatalytic Properties toward Ammonia Oxidation in Acid Solution

AbstractOxidation of ammonia (NH3) using electrocatalyst is highly important because of its usage in fuel cells. In this study, a Cu-ACF composite catalyst was synthesized by the liquid phase deposition (LPD) method with immobilizing copper serving as the active component onto activated carbon fiber (ACF) matrix for the electrochemical oxidation (ECO) of inorganic compounds exemplified by NH3. The electrochemical behavior and surface characteristics of the catalyst, including its redox and corrosion properties, were assessed using cyclic voltammetry (CV), fluorescence spectroscopy (FS), UV-Vis absorption spectroscopy, zeta potential measurements, environmental scanning electron microscopy (ESEM), and transmission electron microscopy–energy dispersive X-ray spectrometer (TEM-EDX). Results demonstrated that applying the CV reversible redox capability could illustrate the catalytic activity of the Cu-ACF catalysts, and the NH3 oxidation current density on the Cu-ACF catalyst increases with increasing scan ra...

Chromium Contamination in Sediments of Anping Harbor, Taiwan

The distribution, enrichment, accumulation, and potential ecological risk of chromium (Cr) in the surface sediments of Anping Harbor, Taiwan, were investigated. Sediment samples from ten locations were collected and characterized for Cr, aluminum, water content, organic matter, and grain size. The results show that samples collected at all monitoring points contain 23.3–881.3 mg/kg of Cr with an average of 250.0±265.4 mg/kg. The spatial distribution of Cr reveals that the Cr concentration is relatively high in the Bamboo River mouth region, and gradually diminishes toward the harbor region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of pollution. Results from the enrichment factor and geo-accumulation index analyses imply that the Bamboo River mouth sediments can be characterized as severe enrichment and moderate to strong accumulation of Cr, respectively. However, results of potential ecological risk index indicate that the sediment has low ecological potential risk. The results can provide valuable information to developing future strategies for the management of river mouth and harbor.

Zinc Contamination in Sediments of Southern Kaohsiung Harbor, Taiwan

Major objectives of this study are to evaluation the enrichment, accumulation, and potential ecological risk of zinc (Zn) in the surface sediments of southern Kaohsiung Harbor, Taiwan. Twelve sampling locations were installed of southern Kaohsiung Harbor to collect sediment samples for analyzing Zn. Results showed that the Zn concentrations varied from 731–946 mg/kg with an average of 323±525 mg/kg. The spatial distribution of Zn reveals that the Zn concentration is relatively high in the river mouth region, and gradually diminishes toward the harbor entrance region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of Zn pollution. Results from the enrichment factor and geo-accumulation index analyses imply that the sediments collected from the Salt River mouth can be characterized very severe degree enrichment and strong to very strong accumulation of Zn, respectively. Results of potential ecological risk index indicate that the sediment has low ecological potential risk.

Distribution and Potential Risk of Copper in Surface Sediments of Anping Harbor, Taiwan

This study was conducted using the data collected at the Anping Harbor, Taiwan to investigate and analyze Copper (Cu) contained in the sediments, and to evaluate the accumulation of Cr and the degree of its potential risk. The results show that samples collected at ten monitoring points contain 23380 mg/kg of Cu with an average of 114±101 mg/kg. The spatial distribution of Cu reveals that the Cu concentration is relatively high in the Bamboo River mouth region, and gradually diminishes toward the harbor region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of pollution. Results from the enrichment factor and geo-accumulation index analyses imply that the Bamboo River mouth sediments can be characterized as severe enrichment and moderate to strong accumulation of Cu, respectively. However, results of potential ecological risk index indicate that the sediment has low ecological potential risk. The results can provide valuable information to developing future strategies for the management of river mouth and harbor.