A hydroponic vertical greening system for disposal and utilization of pre-treated Blackwater: Optimization of the operating conditions

A hydroponic vertical greening system (HVGS) for disposal and utilization of pre-treated blackwater was developed. Orthogonal experiment L9 (33) was applied to select the optimum operating conditions. Moreover, the microbial communities in each group were researched. Experimental results indicate that the highest treatment efficiency was obtained when using 3 cm zeolite as filler substrate for treatment of blackwater under 65 L/m2·d wastewater loading with 49, 34, 33, and 44% of COD, TN, TP, and NH4+-N, respectively. Significant microbial community diversity was observed between nine groups, which had a remarkable effect on the removal of pollutants. This system has good performance in low running cost, effective nutrients, wastewater reuse, and promoting positive ecological effects and landscape superiorities; it would be conducive to popularize this and apply it in the near future.