Plans of using constructed wetlands for wastewater treatment and reuse of the wastewater from the dormitory in the campus

ABSTRACT

   This project was proposed based on the mid-term project of ¡§Building sustainable development of green school¡¨ and Challenging 2008 of National major programs as ¡§Water and green construction program¡¨ and ¡§Promoting program of green campus¡¨ revealed by Ministry of Education.

The main goal of this project is using constructed wetland technology to treat discharged water from the wastewater treatment plant for treating wastewater from dormitory area in campus as well as to setup reclaimed water system. So as to accomplish basic design blueprint as a model for community reorganization, general application, and promoting related technologies.

The working items in this plan include ¡§Monitor and estimation of the discharged water from a wastewater treatment plant¡¨, ¡§Design of constructed wetland system for the further treatment of the discharged water¡¨, ¡§Design of the constructed wetland merged into the ecological and scenic conditions in a campus¡¨, and ¡§Design of the reclaimed water system.¡¨ The complete concept of this plan is hoping to merge constructed wetland into the teaching and extracurricular activities in a school. Ultimately, the wastewater from the campus can be treated directly by a system combined with constructed wetlands, scenic pond, and water tank so as for further reuse.

   The quantity of wastewater from the dormitory area estimated to be 800 CMD. The concentrations of biological oxygen demand (BOD), ammonia nitrogen (NH3-N), and total suspended solids (TSS) were 63, 24, and 70 mg/L, respectively. These measures are used for functional estimation of the design of the constructed wetland system. The planned area is about 10,000 m2 and includes four sections as subsurface flow wetland (SSF), free water surface wetland (FWS), scenic pond, and horticultural area. The areas of these sections are 1,500, 3,500, 1,000, and 4,000 m2. Another water storage tank will be built for collecting final treated water and used for irrigation of the near plants. The concentrations of BOD, NH3-N, and TSS of discharged water were estimated as 16, 9, 12 mg/L, respectively. The detailed design charts for constructed wetlands include whole area distribution, cross sections of SSF and FWS, top view and detailed structures of scenic platform, plane view of wooden bridge, sign board and trail, diagrams of water and electrical systems, plane views of automatic irrigation system and impermeable liner and educating board design, design diagram of bricks, detailed diagram of standard steal, and design budge and standard of constructed wetlands.

    In the ¡§Designs of scenic and reclaimed water system¡¨, other than the scenic pond four 3-dimension diagrams: wooden bridge, trail, sign-boards, and educating boards are also included. Furthermore, fourteen courses contents about constructed wetlands on campus, ¡§Construction standards of constructed wetland on campus¡¨, ¡§Environmental effects by campus constructed wetland¡¨, and some possible problems and the solutions were also planned in this project. The achievements of this project include accomplishments of ¡§Plan of using constructed wetlands for dormitory wastewater treatment and reclaimed water system¡¨, ¡§Suggested plan of sustainable university¡¨, ¡§Solutions of difficulties occurred on operating the wastewater treatment plants on campus during summer and winter vacations¡¨, ¡§Proposed plan for energy saving for operating reclaimed water system¡¨, ¡§Extension of research work on practical application¡¨, and ¡§Achievement of joint effect of academic and application.¡¨

The accomplishments concerning the sustainable campus program of Ministry of Education are providing on-site teaching facility for the teachers and students from all schools and people from near communities; the cumulative information and experiences from this project can be used as reference for other school in similar rebuilt work; practical application of research results of constructed wetland and further reclaiming treated water; providing ¡§General operation and maintenance manual for constructed wetland treatment system¡¨; providing information of theoretical and practical training programs.