Synergistic Removal of Nutrient Pollutants and Pharmaceutical and Personal Care Products (PPCPs) from Contaminated Groundwater: Macro- and Microelements and Microorganisms

Abstract

The synergistic removal performance of nutrient pollutants and pharmaceutical and personal care products (PPCPs) from contaminated groundwater, and the biogeochemical interactions of macro- and microelements–contaminants–microorganisms were further studied. The electrolysis-zeolite/basalt system proved to achieve better synergistic removal performance than all other purification systems considered, reaching average removal efficiencies of 85.8% for nutrient pollutants and 74.7% for PPCPs. Electrolysis not only enhanced the abundance and distribution of MOB and DNB, but also promoted the production of microelements Fe3+ (0.1 ± 0.1 mg/L) and Zn2+ (0.3 ± 0.3 mg/L). Macroelements Ca2+ and Mg2+ increased by 27.8 ± 2.7 and 16.5 ± 9.6 mg/L, respectively, which significantly stimulated the activities of function microbials. Microelements Fe3+ exchanged from zeolite, Mn2+ from basalt, and Cu2+ from groundwater itself were crucial for enzyme activity. Meanwhile, Mn2+ was co-regulated by oxidation–reduction processes and ion-exchange strength. Thus, the electrolysis-zeolite/basalt system is a promising technology for synergistic nutrient pollutant and PPCP removal from contaminated groundwater, especially in dispersive water supplied in the countryside of China.