High-salinity industrial wastewater is difficult to treat. In this study, an evaporation process for use in cooling towers and seawater desalination was adapted to treating high-salinity wastewater under gentle operating conditions. Real wastewater and simulated wastewater containing sodium chloride and glucose were used in this study. An evaporation unit, with an evaporation rate of 5 L/h, was designed and installed in the laboratory. Analysis revealed the effects of operating factors on the quality of condensed water, as well as the relationship between the mass transfer coefficient and wastewater characteristics. The results showed that for the selected system, when the inlet air speed was below 2.5 m/s and the wastewater flow rate was below 1.0 m³/h, the total dissolved solids and the chemical oxygen demand removal efficiencies could reach up to 99.9%. The most significant difference between the mass transfer coefficients of the clean water and simulated wastewater was 30.9% under identical operating conditions. The equation of the mass transfer coefficient considering the density, viscosity, and saturated vapor pressure of wastewater was built to predict the mass transfer efficiency for this process. A case study using real wastewater from a pharmaceutical factory illustrated that the system performed well in practical situations. The predicted mass transfer coefficient agreed well with the measured value. In summary, the developed evaporation system has good prospects for the treatment of high-salinity industrial wastewater.

Background: Berberine (BBR) is a pharmaceutical chemical with a broad antibacterial spectrum, and its biological treatment has been of research and practical interest. In this study, a pure bacterial strain B16 was isolated from the activated sludge in a pharmaceutical wastewater treatment plant. The aim of the study is to characterize the properties of the strain B16, especially its BBR degradation capability. Methods: The identification of strain B16 was conducted by visual observation, as well as biochemical and phylogenetic analysis. The degradation kinetics of strain B16 was tentatively described by Haldane model. Results: The strain B16 was 100% determined as a Sphingopyxis sp. The kinetic parameters of BBR degradation by strain B16 were as follows: Vmax 54.73 ± 5.54 mg (g MLSS · h)⁻¹, Km 66.68 ± 8.95 mg L⁻¹, and Ki 43.16 ± 5.92 mg L⁻¹, with an R² of 0.996. Stain B16 exhibited considerable capability of BBR degradation. BBR of initial concentration 40 mg L⁻¹ could be completely degraded in 48 h under optimal conditions. Conclusions: strain B16 was the first pure culture found with the ability to totally mineralize BBR, indicating the potential of B16 application in real industrial processes.

Two novel multiple component carbon sources, mainly polybutylene succinate (PBS) and polylactic acid, were prepared by twin-screw extrusion to treat simulated groundwater. Both of the composites also contained high-density polyethylene and walnut shell (WS) to adjust the denitrification rate. The composites could release soluble organic carbon and be carriers for bacteria. The addition of foaming agent in the composite enriched the porous channels which increased the surface area for biofilm loading. The results indicated that the average N- removal efficiency in reactor 1 (filled with WS/PBS) was 83%. When the inflow concentration of nitrate changed from 50 to 55 mg L⁻¹, the reactor 1 had an acclimation time of 13 d to accept the high concentration. However, the N- removal efficiency in reactor 2 (filled with WS/PLA) decreased from 86 to 78% because of the propagation of blue-green algae which also led to a high COD value in effluent. WS/PBS was a stable carbon source releaser and could adapt to the environmental change easily. Therefore, it has the potential of using as carbon source of biological denitrification of groundwater.

The tailwater from wastewater treatment plants serves as an important water resource in arid regions, alleviating the conflict between supply and demand. However, the effects of different tailwater discharge proportions on microbial community dynamics remain unclear. In this study, we investigated the effects of different tailwater discharge proportions on the water quality and microbial community characteristics of sediments in receiving water bodies under controlled conditions (WF-1, WF-2, WF-3, WF-4, and WF-5, containing 0% tailwater + 100% natural water, 25% tailwater + 75% natural water, 50% tailwater + 50% natural water, 75% tailwater + 25% natural water, and 100% tailwater + 0% natural water, respectively). Microbial co-occurrence networks and structural equation model were used to unveil the relationship between microbial communities and their shaping factors. Results showed that distinct microbial community compositions were found in the sediments with low- (< 50%) and high- (> 50%) proportions of tailwater. Specifically, WCHB1-41 and g_4-29–1, which are involved in organic degradation-related functions, were the key genera in the high-proportion cluster. A total of 21 taxa were more abundant in the low-proportion (< 50%) cluster than that in high-proportion (> 50%). Moreover, higher modularity was observed in the low-proportion. Total phosphorus directly affected while ammonia nitrogen indirectly affected the microbial community structure. Our findings support the distinct heterogeneity of microbial communities driven by tailwater discharge in receiving water bodies, and further confirmed that high-proportion tailwater depletes sensitive microbial communities, which may be avoided through scientific management.