Enhanced organics and Cu2+ removal in electroplating wastewater by bioaugmentation. (December 2018)

• Record Type: Journal Article
• Authors: Wen, Qinxue; Wang, Qiong; Li, Xinqi; Chen, Zhiqiang; Tang, Yingcai; Zhang, Chongjian
• Is Part Of: Chemosphere. Volume 212(2018)
• Page Start: 476
• Page End: 485
• Publication Date: 2018-12
• Subjects: Electroplating wastewater -- CuO nanoparticles (CuO NP) -- Resistant strain -- Adsorption -- Bioaugmentation; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2018.08.060
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: With the improvement of electroplating process and products requirement, refractory organics, heavy metals or even heavy metal nanoparticles (NP) exist simultaneously in electroplating wastewater inevitably, makes electroplating wastewater treatment effluent difficult to meet the discharge standard. In order to improve the organics removal under the exposure of CuO NP, strains (designated as L1–L5) that have both organics degradation and Cu 2+ tolerance capacities were isolated and employed in the electroplating wastewater bioaugmentation treatment using a hydrolytic/anoxic/oxic-membrane bioreactor. The Cu 2+ adsorption process followed pseudo-second order kinetics and the isotherms fit well to Langmuir isotherm model. L2, L3 and L4 showed higher Cu 2+ adsorption capacity than that of L1 and L5. Under the optimal condition, the maximum Cu 2+ adsorption capacity of L2, L3 and L4 was 34.15, 45.68 and 26.72 mg g −1, respectively. Their average COD removal efficiency achieved 65.7 ± 10.9%, 61.5 ± 6.7% and 71.6 ± 6.0%, respectively. The three isolates were used to construct consortia with the inoculum concentration of 400 mg L −1 . One-time and repeated inoculations were evaluated to find the applicable strategy. Repeated inoculation resulted in a better COD and Cu removal performance (76.2 ± 2.6% and 98.5 ± 0.3%, respectively) than those of one-time inoculation (69.0 ± 2.0% and 98.0 ± 0.3%, respectively). The most functionally stable, balanced and resistant bacterial community was formed in the one-time inoculation system while for fungal community it was formed in the repeated inoculation system. Highlights: First report on the bioaugmentation removal of refractory organics and CuO NPs. The selected strains exhibited excellent Cu 2+ adsorption and organics degradation capacities. Bioaugmentation system with repeated inoculation strategy was more efficient. The most desirable bacterial community was formed in one-time inoculation system. The most desirable fungal community was formed in repeated inoculation system.