The Copper Removal Mechanism In The Presence Of Periphyton Bioreactor Under Wastewater

As the development of social and economy in China, water heavy metal pollution becomes more serious, especially the inflow of large amounts of heavy metal by industrial waste water causing eutrophication and bringing adverse effects on environment and social benefits. How to solve negative problems of low ecological engineering efficiency and unstable running, and how to exploit new ecological technology of high efficiency, environmentally friendly, stability and low price in eutrophic water body, have to be urgently solved in water heavy metal treatment. The core components – periphyton bioreactor in ecological engineering, not only can effectively remove pollutants, and periphyton can indicate changes of environmental quality. However, periphyton bioreactor for heavy metal removal effect and the mechanism is still relatively vague. Therefore, studying the effect and mechanism of copper removal in the presence of periphyton bioreactor under wastewater is conducive to cultivation special periphyton biofilms on different wastewater conditions, increase environmental benefits, the optimization design of ecological engineering and improvement of processing efficiency in ecological engineering.This study carried out research in the following areas: To establish a periphyton accumulation method and characterization techniques; Differences morphological structure and functional diversity of periphyton under different seasons; The copper removal effect and mechanism of periphyton bioreactor in wastewater; the changes of Periphyton biological community composition changes and its own ecosystem stability under copper stress environment; Using optical microscope, environmental scanning electronic microscope(SEM) and Confocal Laser Scanning Microscopy(CLSM) to investigate the periphyton biological community in our study; Using Biolog technology analysis the periphyton biological community functional diversity; Using MiSeq sequencing analysis the changes of periphyton biological community composition.The results show that:(1). Using the fiber material cultivate periphyton can significantly increase microbial diversity; Using WC medium can accelerate the growth rate of periphyton, promote photosynthetic microorganisms as the dominant species, and can meet the needs of ecological engineering and scientific experiment.(2). The morphological structure and functional diversity of periphyton under different seasons were exist significant differences, showing different ability of using carbon source. Reasons to the difference is that the different of main environment driving factors, such as temperature, light, etc. Periphyton can adjust itself to quickly adapt to the environment according to the changes of environment, it indicate that periphyton biotechnology has a good application and prospect in wastewater treatment.(3). the in-situ periphyton bioreactor are efficient in removing different copper concentration from wastewater. Results showed that copper removal by in-situ periphyton bioreactor adsorption dominate. Cu adsorption process followed pseudo-second-order kinetic model and fitted the Freundlich, Langmuir and Dubinin-Radushkevich Isotherms, indicating that it was thermodynamically spontaneous. Therefore, the Cu adsorption process by periphyton in this study could be divided into three steps: external mass transfer at the beginning(0-12 h), intra-particle diffusion in the middle period(12-24 h), and equilibrium during the last period(24-48 h). These results suggest that periphyton can be used as a biological adsorbent for in situ water pollution restoration.(4).Designing a independent bioreactor to research the response process of periphyton under copper stress. The accumulation of periphyton bioreactor not only has a better effect to cultivate periphyton, but also has a copper removal rate as high as 99%. Periphyton can adjust itself to quickly adapt to the environment changes according to change its dominant species or community composition. Periphyton bioreactor main depend on the Specific functions of microorganisms to achieve Wastewater purification. This study can provides some theoretical basis for the development of technology for purifying water quality based on periphyton.