Wastewater Management of Korhogo City
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Asian Journal of Environment & Ecology 11(1): 1-11, 2019; Article no.AJEE.52131 ISSN: 2456-690X Wastewater Management of Korhogo City Kouakou Yao Salomon1*, Seyhi Brahima1, Gnamba Franck Maxime1, Kouassi N’guessan Martial1 and Kouame Nanan Audrey1 1Department of Geosciences, University Peleforo Gon Coulibaly of Korhogo, BP 1328 Korhogo, Cote d’Ivoire. Authors’ contributions This work was carried out in collaboration among all authors. Author KYS designed the study, performed the statistical analysis, wrote the protocol and wrote the first draft of the manuscript. Authors SB and GFM managed the analyses of the study. Authors KNM and KNA managed the literature searches. All authors read and approved the final manuscript. Article Information DOI: 10.9734/AJEE/2019/v11i130126 Editor(s): (1). Dr. Wen-Cheng Liu, Department of Civil and Disaster Prevention Engineering, National United University, Miaoli, Taiwan. Reviewers: (1). Hen Friman, H.I.T - Holon Institute of Technology, Israel. (2). Maria Antonietta Toscano, University of Catania, Italy. Complete Peer review History: https://sdiarticle4.com/review-history/52131 Received 12 August 2019 Accepted 26 October 2019 Original Research Article Published 06 November 2019 ABSTRACT The present study was conducted to provide more information on wastewater management in developing country cities, particularly in Korhogo a city in the north of Ivory Coast. Results showed that 23% of the residences discharge their wastewater either in rivers around the city, in pipes intended for storm water drainage, or on the way for laundry, crockery and/or bath water. 43% and 34% release their water through watertight and non-watertight facilities such as septic tanks and latrines, respectively. A factory evacuates its wastewater directly into the environment without any prior treatment. Only the Regional Hospital (CHR) has a lagoon system which is in a very advanced state of dysfunctioning. The city has a sludge treatment site that receives on average between 30 and 34 m3 per day, well below 100 m3 per day (sizing volume), leading to a significant algal development in the biological treatment basins and a fairly average yield of the plant below 55% at the end of treatment. Keywords: Wastewater; Korhogo; treatment; disposal; sludge. _____________________________________________________________________________________________________ *Corresponding author: E-mail: [email protected]; Salomon et al.; AJEE, 11(1): 1-11, 2019; Article no.AJEE.52131 1. INTRODUCTION 2. MATERIALS AND METHODS It is estimated that well over 80 per cent of 2.1 Presentation of Study Area wastewater worldwide (over 95 per cent in some Korhogo is the fourth largest city of Ivory Coast developing countries) is released directly into the (West Africa) in terms of population and economy. environment without treatment, resulting in Located in the north (Fig. 1), Korhogo (meaning increased water pollution in most rivers of the heritage in Senoufo people), is located about 635 world. In 2012, more than 800,000 deaths km from Abidjan and 356 km from Yamoussoukro, worldwide were caused by contaminated water the political capital. The administrative center of and sanitation services that were almost non- Savanes District, Poro Region and Department, existent or inadequate [1,2]. Sanitation services Korhogo covers an area of 12640.4 km2, involve significant investments in infrastructure, between latitude 9°59' N and longitude 6°49' W. including collection and disposal networks, and The population of the Department of Korhogo wastewater treatment plants. Developed and was 536,851 in 2014 [9]. emerging countries have a lead on this issue, un contrary to developing countries regarding 2.2 Materials the construction sanitation infrastructures. In Côte d’Ivoire, several studies have been The material used for this study consists of a carried out on wastewater in some cities, survey, a map of the city with its neighborhoods, specifically in Abidjan, the economical capital results of CIAPOL (Ivorian anti-pollution center) [3,4,5,6,7]. Some studies have been carried out analyzes and camera for pictures. For physico- in the southern part of the country, including [8] chemical parameters, HACH Multiparameter has works on wastewater management in forest been used to determine temperature and pH, areas. To date, there are almost no study on fiberglass filter for suspended solids, OxiTop wastewater in the northern part of the country. Control OC 110 for BOD, HACH The aim of this study is to provide information spectroph otometer DR 2010 for COD, Total on wastewater management northern part of phosphorus, nitrates and nitrites and total Ivory Coast, especially in the city of Korhogo, nitrogen. A sowing on an agar was used to through the existing sewage disposal and identify and quantify microorsganism. Excel 2016 treatment. and Origin 8.5 have been used for data analyses. Fig. 1. Area of study 2 Salomon et al.; AJEE, 11(1): 1-11, 2019; Article no.AJEE.52131 2.3 Methods phosphomolybdic acid then reduction by ascorbic acid and finally measurement at 875 nm of Wastewater volume data are registered every molybdenum blue. day at the treatment plant since its functioning date. Sampling for physico-chemical and The detection of microorganisms indicating fecal microbiological analyses were done in July 2017 contamination in the laboratory was carried out and May 2018. The methods included a survey by the solid culture method. This technique (May 2018) on sewage disposal ways and requires a step of bacteria cultivation in order to existing wastewater treatment systems in be able to identify them. This step was carried Korhogo. Survey was carried out in the 28 out by sowing on an agar containing the nutrients neighborhoods of Korhogo (Cocody, Quartier 14, and selective substances necessary for the Mongaha...) at residences, schools, guest rooms, growth and identification of the desired bacteria. hospitals and health centers, and factories, with The identification and quantification of indicator a total sample of 1,331, as follows: 1191 micro-organisms was carried out by direct count residences, 63 establishments, 42 hotels and of bacterial colonies. guest rooms, 18 hospitals and health centers, and 17 factories. A visit to the pilot site located in Statistic software Origin 8.5 was used to treat the village of Djigbe in the northern outskirts of data throught variance analysis Anova (One way) the city, let quantification and characterization of to see influence between factors. treated wastewater based on data provided by 3. RESULTS AND DISCUSSION the site services. Sampling and laboratory analysis carried out by CIAPOL. Analyzes 3.1 Wastewater Disposal concerning physico-chemical and biological parameters are summarized in Table 1 and Results of the survey show that autonomous described below. Water sampling was done at 3 sanitation is the mechanism used for sewage points: Inlet water from receiving tank, outlet disposal as in several cities in developing water from drying beds and treated effluent at countries as reported by Heinss et al. [10]. For discharge to environment point. Two types of example, in a city like Ouagadougou, which has measurement were carried out: in-situ about 2 million inhabitants, 97.5% of the measurements (temperature and pH) and population use non-collective sanitation facilities. laboratory measurements. Wastewater samples This kind of disposal is dominated by watertight to be analyzed were kept fresh and sent to the facilities (septic tanks 43%) while non-watertight laboratory. COD was determined by the facilities are represented at 34% for residences colorimetric method (HACH method) with a DR (Fig. 2). These non-watertight facilities would 2010 spectrophotometer after 1/10th samples pose a risk of microbiological contamination of dilution. groundwater, making the groundwater vulnerable Suspended Solids were quantified using to pollution [11], especially since the depth of pressure filtration apparatus. Samples were some structures may reach 10 m. The potential filtered on a fiberglass filter. The filter is then contamination of the water table depends mainly dried in the oven at 105ºC and the mass of the on the type of soil and distance between the residue retained on the filter is determined by bottom of the pit and the level of the water table weighing. during high level periods of water table. A soil layer of 1.5m to 3.0m is recommended between Determination of biochemical oxygen demand the bottom of pit and groundwater table, and a (BOD) was done by using an OxiTop Control OC distance of 30m (at the surface) between latrines 110. Manipulation is simple, easily controllable and a source of drinking water is recommended and non-toxic because mercury-free. After 5 days, to limit exposure to chemical and biological values are directly read in mg/l BOD because the contamination [12]. This water pollution has been measured pressure is automatically converted. demonstrated by several studies in developing countries [13, 14]. It should also be noted that To determine total phosphorus, a thermal 23% of residential sample discharges their digestion of the sample in acid and oxidizing wastewater either into rivers around the city, or conditions was carried out, before colorimetric into drainage canal for storm water, or on the measurement of released o-PO4 released. way for laundry, crockery and/or bath water (Fig. Organic and inorganic phosphate compounds 3A). These habits would not only pose risks of are oxidized by addition of