Physico-Chemical and Bacteriological Analysis of Waste water from Hospital 'Case of Centre University Teaching Hospital of Kigali'
Abstract
Hospitals produce relatively huge amount of wastewater containing pathogenic microorganisms, toxic, laboratory and pharmaceuticals residuals, disinfectants, biodegradable, polluters and radioactive contaminants that are potentially threats to population health and the components of environment when they are discharged without proper treatment.
The purpose of the study was the assessment of water quality effluent from CHUK wastewater treatment plant (CHUK WWTP) by analyzing physico-chemical and bacteriological parameters. Sampling has been take place at different points and time better understanding of how hospital unit operations affect the effluent quality. A sum of twelve (12) samples were collected in three (3) trials at four (4) different points in Nyarugenge, Gitega and at the border with Kimisagara sector especially Mpazi stream where CHUKWWTP’seffluents are discharged. Samples collection, conservation, preparation and measurement took place at university of Rwanda-college of science and technology (CST) laboratory. The obtained results at WWTP outlet, at point of meeting with Mpazi stream, Mpazi stream and mixture of Mpazi stream with CHUK effluent were Cu (0.06, 0.07, 0.05 and 0.07mg/l); Fe (0.13, 0.037, 0.037 and 0.034mg/l); Pb (0.021, 0.024, 0.024, and 0.027mg/l); Hg (0.0015, 0.003, 0.003 and 0.004 mg/l) respectively. pH (7.25, 812,7.74 and 7.4); COD (215.5, 122.4, ,145.5 and 187.2mg/l); BOD5 (29.3, 30.85, 29.4 and 27.3 mg/l); TN (3.29, 2.97,3.2 and 3.46 mg/l); TP (1.05, 0.91, 0.92 and1.05mg/l); NH +(7.46, 8.5,7.5and 8.8 mg/l); TSS (77, 56.5,62.8 and 69.1mg/l); fecal (282, 263,270, and 273 CFU/ml) 4 and TC (233, 213, 224 and 210 CFU/ml). These parameters are prescribed within the reference limits of Rwanda Standard Board (RSB) and World Health Organization (WHO) standards, thus they have no negative side impact and effects on the receiving environments and their components.
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Introduction
Wastewater can be defined as any water, whose quality has affected or being abused by anthropogenic influence (petrovic, 2010). These are liquidious waste released from domestic homes, industries, hospitals, agricultural and commercial sectors (barchelo, 2010). Most of the liquid wastes from hospital are categorized as non-regulated “emerging pollutants (EPA, 2016). According to Amouiei, Barcelo and Petrovic2010: the exposure to hospital wastewater released without adequate treatment in surrounding environment and its components results to adverse effects on the biological balance of aquatic ecosystems, causing imbalance at different trophic levels possibly related to the action of toxic and genotoxic agents and indirectly lead to eutrophication on water bodies surface.
The quality, nature and risk assessment of released effluents are described by its flow, sources of generation, physico-chemical and microbiological characteristics (Galletti ,2010). Addition to this findings of miscellaneous research done on hospital effluent show that effluent discharged from hospitals usually contains certain harmful pollutants such as: pathogenic microbes and bacteria, residues of medicine, laboratory chemicals, pharmaceuticals residues, biodegradable organic materials, carcinogenic metals, and radiation emitting wastes which are danger to the life of the living organisms and environment (Verlicchi ,2010; Kanama,2018). Hospital effluents are released into water bodies (streams, rivers and lakes) through sewer and cause the deviation from baseline situation of the received environment which is negatively affecting the ecological balance and life if they left with its pathological, radioactive, product of pharmacy, chemical and infectious components lead to diseases, cancer epidemics, skin diseases and contaminate air, water and landholder components (kumar, 2007)
According to (Verlicchi,2015) effluent discharge from hospitals wastewater treatment with low capacities of pollutants removal create high demand for oxygen like BOD, COD in receiving water bodies and deviate the aesthetic value of aquatic ecosystems while research finding of Carraro,2016 state that: some hospital treatment facilities for liquid wastes (HWWTP) are not properly managed and slightly show low removal capacities for common parameters including BOD5, COD, TSS, heavy metals (mercury and lead), coliforms ,total nutrients (total nitrogen, phosphorus and ammonium). At the beginning of 1928, University teaching hospitals of Kigali (CHUK)located in Kigali City, Nyarugenge district, Nyarugenge Sector, in its daily activities requires large volume of water, the reason why more wastewaters are generated and use sewer passing through Nyarugenge, Gitega Sectors and meet with Mpazi stream passing through Kimisagara sector and this lead CHUK to be a particular example of hospital discharging effluents into surrounding environment. However, there is no known study done on CHUK hospital effluent and small effluents data exist in Rwanda on hospital effluents characteristics (Aurelian, Sylvie, 2013).
Currently, the statistics data from ministry of health show that the number of patients cared by CHUK hospital have increased at 45% in 10yesars ago while its treatment plant has not expanded and replaced. This cause to higher need of large volume of water and release to much wastewater which can surpass the existing capacity of treatment facilities leading to discharge of effluents which are not matching with required standards of receiving environment and aquatic ecosystems. The population of above stated sectors use Mpazi stream as source of water in their daily activities like watering, washing and cleaning while the quality, physicochemical and bacteriological composition of Mpazi stream water after mixing with the effluent from CHUK water treatment plant are not well already known.
According to water Aid report of 2013, department of water and sanitation report of 2017, Rwanda loses RWF32 billion annually due to poor sanitation and It’sapproximated that 7,200 Rwandans including 6,100 children under 5, die each year from poor sanitation related diseases, nearly 90% of which is directly attributed to poor water, sanitation and hygiene. Several research studies have done by analyzing the quality and composition municipal wastewater ’effluents but there is big gap about analyzing hospital wastewater ’effluents in Rwanda Where some parameters like mercury(Hg), Lead (Pb) and other heavy metals were left aside and Kigali city is apart of the above issues.
The aim of the research study was to assess the quality of the effluent from Centre university teaching hospital of Kigali wastewater treatment plant (CHUKWWTP) by analyzing the physical, chemical and bacteriological parameters and this overcame the gaps appeared on analysis of effluents generated from hospitals in Rwanda and showed the current data of CHUK hospital effluent discharged , and increase the safety of receiving environment, the report is supposed to be used by the ministry of health, water and environment regulating agencies and CHUK hospital to improve the quality of their effluents through regular maintenance of its WWTP.
Conclusion
5.1 Conclusion The physico-chemical and bacteriological parameters analyzed from CHUK WWTP effluents discharged in Mpazistream towards Nyabugogo River were measured, analyzed, interpreted in the research study. After data analysis and compared with the WHO standard, the effluents result of Cu, Fe, Pb,Hg, COD, BOD5, and TSS, total nitrogen, phosphorous ,ammonium and microbiological concentrations were all meet the limit of standard recommended WHO and RSB and have no negative effects on the receiving environment. The decrease in concentration for all parameters from initial point (point one) of sampling to Mpazi stream justified the performance and effectiveness CHUK WWTP with environmental treatment while the increment from effluent to Mpazi stream are suspected to be originated from other discharge of nearby institutions and anthropogenic activities carried around sewer system.
As stated in the hypothesis, the pollution was supposed to be evaluated based on comparison of effluents results with the standard, therefore comparison shows that as all results of CHUK effluent are prescribed within the limit of WHO and local standard from Rwanda standard board, thus CHUK Hospital is not polluting the environment and its component at all. 5.2 Recommendations After evaluating the quality effluents from CHUK WWTP and those received by Mpazi stream the following recommendations should be noted, acton that and take into account. CHUK should measure the effluents released from their wastewater treatment plant week per week because the results of the research are based on the samples taken weekly and show high variability. CHUK should offer trainings to their employees about cleaner production while ensuring maintenance of WWTP by regular replacing the oldest deteriorated equipment, this will reduce the volume wastewater generated and cut treatment cost. Interested parties should sensitize the people located in NYARUGENGE, GITEGA, and KIMISAGARA sectors that using Mpazi stream as source of water for drinking and washing is not allowed and forbidden. Rwanda environmental, health regulatory agencies should do surprise consultancy and inspections provide the reports to ensure that the obtained results are reliable and consistent. Discharge standards must be based on current scientific data. It supposed to be an obligation for the industries to have laboratories which can be used to prove whether their discharge are proportional to those required standards. The penalties should be increased to the extent of being a preventive mechanism. The technology about treatment of liquid wastes should be specific and the monitoring system should be improved indifferent institutions The polluter pay principle and cleaner mechanism should be applied in order to minimize the quantity of waste generated. More research should be done periodically indifferent season to support and update the current results. The last one, fences must be constructed nearby CHUK sewer system to avoid accident as it is crosscutting habitant area in Gitega sector.
