Evaluation of a constructed wetland for removal of some physicochemical and microbiological contaminants from wastewater in a residential tertiary institution in Nigeria

Authors

  • Felix A. Oginni
  • Solomon A. Isiorho

Keywords:

sewage, wastewater, influent, effluent, wetland, water hyacinth

Abstract

Covenant University is a residential tertiary institution in Canaan land, a large faith based facility, whose population can be more than 75,000 during Sundays religious activities in Ota, Ogun State, Nigeria.  Sewage from this community is treated by a series of constructed wetland located in the University, with its effluent discharging into a canal that empties into River Iju.  This river is used by several hundreds of thousands of people downstream.  The effluent flows through six sets of constructed wetlands, each with four chambers and the treatment process in the wetlands was evaluated by its adequacy and efficiency.  Input and output of the system were monitored.  Results indicated that the series of wetland reduced the total dissolved solids (TDS) by only 8% and conductivity by 11%, while the pH was constant at 6.8.  The microbiological test results indicated a 99% reduction in the most probable number of coliforms (MPN) from 1,600 cfu/100 mL.  The constructed wetland achieved 85%, 79%, 52%, 79%, 66% and 83% reduction for coliform, staphylococcus, salmonella, salmonella and shigella, total viable count, and fungi, respectively.  Results of the colony units/mL, cfu/mL, for these parameters, obtained at both upstream and downstream and at the point of discharge into the canal compared with those at the effluent point showed adequacy of removal of contaminants by the constructed wetland series.  The efficiency of the wetlands can be enhanced further by slowing the flow rate and increasing the number of wetland chambers.  Further work is required to determine the rate of recovery of the polluted canal water.

 

Keywords: sewage, wastewater, influent, effluent, wetland, water hyacinth

Author Biographies

Felix A. Oginni

Biographical Sketch                                                                                     

Felix A. Oginni began his career in research as the Agricultural Engineer for The Soil Water, Research and Development Sections of the Engineering Division of Oyo State Ministry of Agriculture and Natural Resources, MANR, Ibadan, Nigeria in August, 1976. Barely 3 months later he joined National Horticultural Research Institute at Idi-Ishin, Ibadan, Nigeria as Pupil Irrigation Officer. In 1978, he commenced Engineering Practice in the areas of Water Resources, Irriagation, Drainage, Flood Control, and Environmental Engineering at Osot Associates a Consulting Civil Engineering firm in Ibadan, Nigeria. This same year he began teaching on Part-Time basis at The Polytechnics, Ibadan. Since then Felix has been involved in the practice of Civil Engineering as Consultant carrying out field investigations, studies and design on team works and some teaching. On many occasions he has been the Team leader. He became more involved as faculty of University of Ado-Ekiti, Ado-Ekiti, Nigeria in 2003, IgbinedionUniversity, Okada, Benin, Nigeria in 2005 and Covenant University, Ota, Nigeria, in 2007. He is also on board of some Construction companies.

 

Educational Background

Oginni graduated from the University of Ife, now Obafemi Awolowo University, Ile-Ife, Nigeria in 1975 with a B.Sc.(Honours) in Agricultural Engineering. In 1982, he obtained Ph.D. in Civil Engineering from the UniversitySouthampton, Southampton, United Kingdom, (UK). He also obtained a Postgraduate Diploma in Management Studies from Portsmouth Polytechnic, Portsmouth in UK. He was a Western State Marketing Board, Nigeria Scholar, 1972/73 and British Commonwealth Scholar, 1979-1982. of

 

Professional Engineering Practice and Teaching.

Dr. Oginni, combined engineering practice in consulting and field investigation works with academics since 1978 at Osot Associates, a Consulting Engineering firm and rose to the position of a Partner in 1985. He was the Team Leader that carried out the Hydrographic Survey of River Rima Training, a 348km river stretch in 1983 In 1990, he joined DECS Associates, another Consulting Engineering firm, where he became the Principal Partner (Nigeria). He is the Chief Executive Officer, CEO, Kafnog Limited, a Construction Company, since 1993. He is also the Technical Director, AlphaPride Limited, a Design, Cost Management and Civil/Building Construction Company. His love for imparting knowledge took him to The Polytechnics, Ibadan as Part-Time Lecturer in the Department of Civil Engineering in 1977, Part-Time Senior Lecturer, University of Ado-Ekiti in 2003 to date. He was Head of Department, HOD, of Civil Engineering in Igbinedion University, Okada, Benin City in 2006 and Acting HOD (Civil Engineering), Covenant University, Canaan Land, Ota, Nigeria in 2007.

 

Field of Specialization

Dr. Oginni has carried out investigations on many aspects of water resources and environmental engineering. He is currently researching into modeling removal of microbiological contaminants in constructed wetlands, waste disposal and ‘pure water’ quality issues in Nigerian cities; appropriate maintenance schedules for Imhoff tank in waste disposal plants; variation of water quality within urbanized river stretches, and development of software for simulation of hydrological events. He is a Reviewer of The Covenant Journal of Science and Technology (CJST) Journal Articles.

Solomon A. Isiorho

Department of Geosciences, Indiana University – Purdue University, Ft. Wayne (IPFW),

    Fort Wayne, IN 46805, USA

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Published

2014-09-30

Issue

Vol. 16 No. 3 (2014): CIGR Journal

Section

I-Land and Water Engineering