Molecularly Imprinted Polymer Microspheres Enhanced Biodegradation Of Bisphenol A By Acclimated Activated Sludge

Bisphenol A (BPA) is a widely used intermediate in the production of polycarbonate plastics and epoxy resins. As one of the most ubiquitous environmental estrogen disruptors, BPA can cause adverse health effects on ecosystems and on human being by mimicking or interfering hormonal activities to affect growth, development, and reproduction. The health impacts of BPA may be cumulative and are irreversible, endangering the sustainable development of humans. Even trace BPA produces adverse effects on aquatic life.These trace phenolic environmental estrogens are stable and poor biodegradability. As a result, no effective treatment is available currently for phenolic environmental estrogen pollutants.Molecularly imprinted polymers (MIPs) are a class of smart sorbents for separation procedures and chemical analyses. MIPs exhibit high affinity and selectivity for template and its closely related analogues. Nowadays, MIPs have been widely used in biological, pharmaceutical and environmental research.In this study, BPA was chosen as the template to synthesize imprinted polymeric microspheres (MIPMs) by precipitation polymerization method. Then BPA-imprinted MIPMs were mixed with activated sludge to evaluate the potential impacts of MIPMs on biodegradation. The main contents are described as follows:1. Bisphenol A imprinted polymeric microspheres (BPA-MIPMs) were synthesized by precipitation polymerization. Polymer morphology, selectivity and binding characteristics were evaluated. Achieved particles were globular and narrowly dispersible with diameters of 0.7μm. The B_max(the maximum number of binding sites)for the MIPMs and nMIPMs used in this study were 5.33 mg/g and 0.96 mg/g respectively. IPB (imprinting-induced promotion of binding) values were 318, 221, 214 and 183% respectively for BPA, BPC, BPZ and HAP.2. The activated sludge was acclimated to degrade BPA effectively. L₁₆(4³) table including three factors (shaking speed of water bath incubator, pH, temperature) and four levels were used to explore the optimal BPA degrading conditions. From orthogonal test, Shaking speed 150 rpm, 35℃and pH=7 were the optimized degradation conditions.3. Due to the selective adsorption of MIPMs to BPA and its analogues, addition of MIPMs to activated sludge increased levels of BPA and its metabolites, higher substrates (BPA and its metabolites) level promoted biodegradation efficiencies of activated sludge. The enhancement of MIPMs in degradation efficiencies was more significant in environmental water containing low level of pollutants, and water containing interferences such as heavy metals and humic acid. Furthermore, MIPMs were more suitable than non-selective sorbents such as active carbon to be used as enhancer for BPA biodegradation.