Ozone pollution, which can be caused by photochemical reactions, has become a serious problem. The ozone formation potential (OFP) is used to describe the photochemical reactivity. Volatile organic compounds (VOCs) are main precursors of ozone formation, and wastewater treatment plants (WWTPs) are important sources of VOCs. Therefore, it is necessary to study the concentration level and OFP of VOCs from WWTPs. In this work, a coking WWTP with anaerobic-oxic-oxic (A/O/O) processes in Shaoguan city, Guangdong province, China, was selected to investigate the characteristics of VOCs at wastewater treatment areas and office areas. The OFP of VOCs was estimated by the maximum incremental reactivity (MIR) coefficient method. Results showed that 17 VOCs were detected, and the total concentration of VOCs was the highest at the raw water tank (857.86 μg m⁻³). The benzene series accounted for 69.0%–86.9% and was the main component of VOCs in the WWTP. Based on OFP data, the top six VOCs contributing most to the OFP were m-xylene, toluene, p-xylene, o-xylene, styrene, and benzene. This study provides field data and information on the environmental risk of VOCs for coking companies and environmental departments. We found that the priority control sources of VOCs were wastewater treatment units because of their larger OFP contributions.

Facing the current gaps with regard to the momentum effect in Chinese securities market, a momentum strategy was constructed to compare the securities market price under the effective market theory with under the non-effective market theory by the Hushen 300 index from 2006 to 2015 and a stock price residual measurement model. An important result was that the root cause of the momentum effect was systematic irrational behavior. On this basis, a new momentum strategy was constructed based on RSP (Residual of Stock Price), and the performance of that strategy was tested in different ranking and holding periods. The new momentum strategies were obtained positive average cumulative abnormal returns in the super short-term, short term and medium term. This finding confirmed the significant existence of the momentum effect in China’s stock market and the validity of the RSP momentum strategy. Therefore, this finding can be contributed to effectively addressed the current gaps and examine the applicability of classic asset pricing theory and behavioral finance theory in China's stock market. Finally, after considering the transaction costs, the momentum strategy is effective in both theory and practice.

Dye wastewater is a typical refractory organic wastewater. Advanced oxidation processes have been proven to be an effective way for treating high concentration dye wastewater. This method, which activates peroxymonosulfate (PMS) with cobalt-based catalysts and produces sulfate radicals, has garnered significant research interest. This study developed a highly efficient and environmentally friendly cobalt-based catalysts Co–Ce–Ru/γ-Al₂O₃ via an impregnation method for enhanced activation of PMS to degrade rhodamine B (RhB) in wastewater. The innovative incorporation of rare-earth metal Ce and precious metal Ru into Co/γ-Al₂O₃ significantly reduced cobalt loading while improving catalytic activity and stability. The decolorization rate of RhB in dye wastewater was used as the degradation performance index. Results showed that the decolorization rate of RhB using Co–Ce–Ru/γ-Al₂O₃ catalyst was close to 100% when the system temperature was 25 °C, the amount of catalyst was 0.5 g/L, the amount of PMS was 0.5 g/L, and the concentration of RhB was 50 mg/L. Importantly, the catalyst exhibited exceptional durability with minimal metal leaching (< 1.0 mg/L) over multiple cycles, complying with environmental standards. This work provides deep insights into the catalytic mechanism and kinetics of PMS activation, offering a practical and sustainable solution for the treatment of dye-contaminated wastewater.