Multiple fouling dynamics, interactions and synergistic effects in brackish surface water distribution systems

Dissolved salts, colloidal particles, and active microorganisms in brackish surface water distribution systems (BSWD) cause multiple fouling, poses potential threat to the environmental pollution, and raising technical and economic issues as well. So far, the co-occurrence and interactions of multiple fouling remains largely unknown. Multiple fouling behaviors were assessed in agriculture BSWD under different nitrogen (N) fertilizers. X-ray diffraction, Rietveld refinement analysis, 16S rRNA, and microbial network analysis were conducted to determine the fouling characteristics. Statistical analysis was applied to reveal the relative contributions and interaction of multiple fouling. Our results demonstrated, multiple fouling of precipitates, particulates and biofoulings were co-occurred. Fouling growth was largely attributed to the strong interactions of different fouling. The binary interactions of precipitates particulates contributed 51.1%, and ternary interactions of precipitates particulates biofouling contributed 25.4% to explain the decline of system performance, while the contribution of each single type fouling was minimal. Thereby indicating the significant role of calcium silica, biomineralization and bio-silicates in fouling. The lower acid N fertilizer broken the interaction of multiple fouling by increasing the precipitate crystal parameters and repulsive forces amongst particulates, as well as destroyed microbial interactions in biofouling. Overall, this study open frontier for multiple fouling in-depth profiling and antifouling guidance for effective utilization of BSWD.

Automated summary

This study revealed that multiple fouling in brackish surface water distribution systems is mainly caused by strong interactions between different types of fouling, with binary interactions between precipitates and particulates contributing 51.1%, and ternary interactions between precipitates, particulates, and biofouling contributing 25.4%. Calcium silica, biomineralization, and bio-silicates play significant roles in fouling. Moreover, the use of low acid nitrogen fertilizers can disrupt the interaction of multiple fouling by altering the crystal parameters of precipitates and increasing repulsive forces between particulates, as well as disrupting microbial interactions in biofouling.