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As salicylic acid (SAC) is an extensively used pharmaceutical, discharge of SAC into the environment has caused serious threats to ecology in view of its toxicity. Therefore, SO4•−-involved chemical oxidation methods have been employed for eliminating SAC. Since monopersulfate (MPS) has become a popular reagent for producing SO4•−, an alternative heterogeneous Co-based catalyst is proposed by using a Co-coordinated covalent organic polymers (Co-COP) as a precursor. Via carbonization, Co-COP is transferred by conversion of Co ions to Co/CoO nanoparticle and conversion of COP to N-doped carbon nanocapsules (CNC), respectively, to form a unique composite of Co NPs embedded into carbon nanocapsule (CoCNC). CoCNC exhibits a higher catalytic activity than Co3O4 nanoparticle for activating MPS to degrade SAC because of synergistic effects between Co NPs and the N-doped CNC which not only acts as the support but also provides active sites. Hence, CoCNC+MPS could afford a much lower Ea value (25.4 kJ/mol) of SAC degradation than the reported values. Moreover, CoCNC is still efficient for removing SAC even in the presence of high-concentration NaCl and SDS. CoCNC can be also recyclable over many cycles and maintain its catalytic activities, confirming that CoCNC is an advantageous catalyst for MPS activation.

Metal Organic Frameworks (MOFs) receive increasing attention for 4-nitrophenol (4-NP) reduction; however the existing studies of using MOFs for 4-NP reduction all involve with noble metals. Moreover, the reported MOFs are very fine powders which are inconvenient for realistic implementation. Thus, the present study proposes to develop a MOF foam which exhibits macroscale features of foam and microscale functionalities of MOFs. Specifically, a Cu foam is selected as the macroporous substrate which serves as a porous support and the metal source for synthesizing Cu-based MOF, HKUST-1, via an one-step electrochemical method. The resulting HKUST-1 foam can act as a convenient catalyst for reduction of 4-NP to 4-AP in either batch-type or flow-thru-type reactions. The corresponding activation energy (Ea) of 4-NP reduction (43.3 kJ/mol) is also significantly lower than Ea values of reported catalysts, including noble metal catalysts, whereas the corresponding TOF (48.3 min−1) is higher than many other catalysts. HKUST-1 foam can also efficiently catalyze reduction of methylene blue (MB) to fully decolorize its color. In addition, HKUST-1 foam could be reused over multi-cycles and retain its activity for reduction of 4-NP and MB. These features validate that HKUST-1 foam is a practical, convenient, and reusable catalyst for reduction of 4-NP.

Wetland biomass has potentials for bioenergy production and carbon sequestration. Planted with multiple species macrophytes to promote biodiversity, the 3.29 ha constructed wetland has been treated 4000 cubic meter per day (CMD) domestic wastewater and urban runoff. This study investigated the seasonal variations of aboveground biomass of the constructed wetland, from March 2007 to March 2008. The overall aboveground biomass was 16,737 kg and total carbon content 6185 kg at the peak of aboveground accumulation for the system emergent macrophyte at September 2007. Typhoon Korsa flood this constructed wetland at October 2007, however, significant recovery for emergent macrophyte was observed without human intervention. Endemic Ludwigia sp. recovered much faster, compared to previously dominated typha. Self-recovery ability of the macrophyte community after typhoon validated the feasibility of biomass harvesting. Incinerating of 80% biomass harvested of experimental area in a nearby incineration plant could produce 11,846 kWh for one month.

Typhoons and hurricanes in subtropical/tropical regions can induce significant environmental changes (e.g., mass flooding and inundations). However, the damage to the pollutant removal efficiencies of constructed wetlands brought about by these natural disturbances has been neglected in major studies conducted in temperate climates. Therefore, this study compares the pollutant removal performance of a constructed wetland in the Danshui River Basin, before and after the system was inundated with flooding from Typhoon Krosa in 2007. The pollutant removal performance of the free water surface (FWS) constructed wetland was investigated monthly from September 2006 to April 2008. Results of the study demonstrated that this FWS wetland effectively removed 64.3% BOD, 98.9% NH(4)-N, and 39.5% Total-P before Typhoon Krosa. However, the extensive flooding caused by Typhoon Krosa swept over most of the aboveground plant community and deposited the sediment onto the bottom of each compartment. Subsequently, reduced pollutant removal efficiencies were observed. Only 37.7% BOD, 35.1% NH(4)-N, and 31.8% Total-P were removed after this event, although the flow regime was immediately restored. Comparing the water quality data for the FWS wetland before and after Typhoon Krosa revealed the immediate, quantitative damage to the pollutant removal performance caused by the typhoon's inundation. Consequently, a high-flow bypass and additional preventive measures would protect any constructed wetland in areas subject to typhoons.