Removal of benzo[a]pyrene from soil in a novel permeable electroactive well system: Optimal integration of filtration, adsorption and bioelectrochemical degradation

Magnetic Covalent Organic Framework Composites for Wastewater Remediation

Covalent organic frameworks (COFs) with high specific surface area, tailored structure, easy functionalization, and excellent chemical stability have been extensively exploited as fantastic materials in various fields. However, in most cases, COFs prepared in powder form suffer from the disadvantages of tedious operation, strong tendency to agglomerate, and poor recyclability, greatly limiting their practical application in environmental remediation. To tackle these issues, the fabrication of magnetic COFs (MCOFs) has attracted tremendous attention. In this review, several reliable strategies for the fabrication of MCOFs are summarized. In addition, the recent application of MCOFs as outstanding adsorbents for the removal of contaminants including toxic metal ions, dyes, pharmaceuticals and personal care products, and other organic pollutants is discussed. Moreover, in-depth discussions regarding the structural parameters affecting the practical potential of MCOFs are highlighted in detail. Finally, the current challenges and future prospects of MCOFs in this field are provided with the expectation to boost their practical application.

Bio-electrical stimulation process on degradation of Phenanthrene from aqueous solution using a novel anode modified with carbon cloth: Operational performance, microbial activity and energy

Phenanthrene as the hazardous PAHs-component are extensively detected in industrial wastewater. However, the impacts of bioelectrostimulation process on Phenanthrene degradation in aerobic reactors remained unclear. Here, a novel bioelectrostimulation process equipped with carbon cloth as electrodes was developed to investigate the removal efficiency of Phenanthrene and ATPase enzyme activity in the synthetic wastewater. The results obtained from the present study indicated that a complete Phenanthrene degradation (100%) can be achieved using microbial electrostimulation systems steel mesh coated with carbon cloth (MES-CC) as anode under optimal operational conditions (electrical current: 4 mA, HA concentration: 15 mg L^-1) within 18 h. The conductive carbon cloth provides a biofilm carrier to easily transfer the electrons between electrodes and microbial communities. In addition, the highest ATPase enzyme activity (5176 U) was observed when the aerobic MES-CC reactors were operated with electrical current 4 mA. Furthermore, the COD removal efficiency in MES-CC increased from 49% to 96% when the C: N ratio decreased from 20 to 5. The highest value of V_max in MES-CC for suspended and attached growth were determined to be 2.87 and 0.54 g COD g^-1 biomass. Overall, the results demonstrated that MES equipped with carbon cloth and continuous electrical current mode has good potential for efficient Phenanthrene wastewater treatment.

Effects of water flow on performance of soil microbial fuel cells: Electricity generation, benzo[a]pyrene removal, microbial community and molecular ecological networks

Soil microbial fuel cells with water flow (W-SMFCs) as a driven force of substrate transport were constructed. Electricity generation, benzo[a]pyrene (BaP) removal, microbial communities and microbial molecular ecological networks were compared between W-SMFCs and their control reactors (without water flow, C-SMFCs) in 240 days of operation. The W-SMFCs started up faster than C-SMFCs (37 days vs. 50 days) and output higher startup voltage (148.45 mV vs. 111.90 mV). The water flow caused higher removal efficiency of BaP at sites >1 cm from the anode (S _{> 1 cm}) than at sites <1 cm from the anode (S _{< 1 cm}) in W-SMFCs, whereas in C-SMFCs, the removal efficiency of BaP at S_{< 1 cm} was higher than that at S_{> 1 cm}. The removal efficiency of BaP at S_{> 1 cm} in W-SMFCs was up to 1.7 times higher than that at S_{> 1 cm} in C-SMFCs on the 91^st day. After 240 days of operation, the biodegradation efficiency of absolute BaP amount was 45.95% in W-SMFCs, being 20% higher than that in C-SMFCs (38.17%). Moreover, the water flow caused highly tight interaction among the microbial species, which could be beneficial to BaP biodegradation. Conclusively, the water flow in soil was very beneficial for startup and biodegradation of BaP in SMFCs.