摘要
Cellar water DOM presented LMW, low aromaticity and high nitrogen contents. • Toxicity of disinfected cellar water is nearly 2.5 times that of surface water. • UV/SPC-BAC reduced chlorinated cellar water toxicity by nearly 75%. • UV-SPC-BAC mitigates toxicity by lowering DOM unsaturation and unknown CHONCl. Cellar water harvested from rooftops is recognized as a valuable alternative source for alleviating global water scarcity. Nevertheless, accumulated multi-source pollutants pose a high risk of toxic disinfection by-product (DBP) formation during disinfection. In this study, a pilot-scale system was established to control DBP-associated toxic risks. Compared with local surface water, simulated rooftop-harvested cellar water contained elevated organic matter (3.18 ± 0.23 mg/L), with nitrogenous organics (CHONs, CHONSs) accounting for 49.94% of total organic molecules. Accordingly, chlorinated cellar water exhibited 2.85-fold higher cytotoxicity and 2.44-fold higher genotoxicity than chlorinated surface water. Conventional coagulation-sand filtration preferentially removed high-molecular-weight CHO fractions yet leaves abundant hydrophilic nitrogenous organics uneliminated. In contrast, the ultraviolet/sodium percarbonate-biological activated carbon (UV/SPC-BAC) process drastically reduced molecules from 6687 to 3113, with marked declines in CHONs and CHONSs. Separate UV/SPC oxidation or BAC filtration reduced DBP-related toxicity by only 20.2% - 30.6%, whereas the combined UV/SPC-BAC process achieved nearly 72.0% toxicity reduction. Significant declines also occurred in the calculated additive toxicity index of known DBPs and the abundance of unknown DBPs. Mass difference analysis revealed that UV/SPC-BAC preferentially eliminates unsaturated and nitrogenous fractions, suppressing oxygen addition during post-chlorination and mitigating nitrogenous DBP formation potential and toxicity. Download: Download high-res image (214KB) Download: Download full-size image
危险品化学品经营许可证（带存储）