Physico-chemical and Microbiological Qualities of Abattoir Wastewater in Egbu, Imo State, Nigeria

Abbattoir waste water is of a complex composition. When discharged without being treated, poses a threat to human health and the environment. This is the practice common in Nigeria, and is worrisome.Objective: The aim of this study was to assess the physico-chemical and microbiological qualities of waste water from Egbu abattoir discharged into ‘Otamiri’ river in Owerri North local government area, Imo State, Nigeria.Methods: The microbial quality of abattoir wastewater was studied. The duration of the study was three months, from June to September, 2019. Sample collection was done in the morning (8-10am) and in the evening (4-6pm). A total of thirty samples (30) were collected from two sampling points, at the place of generation of the wastewater (Effluent source) and at the point of discharge into the river (POE). Standard methods were employed to assess the microbiological and physiochemical quality of the effluent. The microorganisms isolated from the samples included Escherichia coli, Salmonella, Staphylococcus, Aspergillus, Mucor, Listeria, Micrococcus and Candida species. The Total Heterotrophic Count (THC) of effluent samples, at source and POE were 8.51log10 cfu/ml and 6.15log10cfu/ml respectively, Total Coliform Count (TCC) for same samples were 6.77log10 cfu/ml and 4.56log10 cfu/ml respectively. The Total Fungal Count (TFC) of the effluent samples at source and at POE was 5.19log10 cfu/ml and 4.18log10 cfu/ml respectively. Results further revealed that the pH of the effluent at source was 6.58 while that at Point of Entry into the river was 7.30. The temperature of both samples was 25oC. The Total Dissolved Solid values of the effluent collected at source was higher, having a value of 1400mg/L against 1000mg/L at Point of Entry. Also the Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) values of the effluent at source were 5.10mg/L and 8.58mg/L respectively, while the BOD and COD of the water at the POE were 4.3mg/L and 7.9mg/L respectively.Conclusion: Abattoir wastes are becoming a major environmental health challenge and being discharged into the Otamiri River indiscriminately is of public health concern. The potential public health implications associated with discharging untreated abattoir wastewater into the environment and thus, the need for adequate treatment to ensure decontamination as well as providing wastewater treatment facility is imperative.

"Ensamblaje" de macroinvertebrados acuáticos y su relación con variables fisicoquímicas en un río de montaña en Colombia

Debido a la influencia de diferentes actividades humanas, los ríos y su biodiversidad están bajo tensión. El objetivo de este estudio fue evaluar la diversidad de los macroinvertebrados acuáticos del río Jordán (Valle del Cauca) y su relación con variables fisicoquímicas. En el tramo evaluado (5 650 m) se realizan actividades de minería, captación de agua, ganadería, agricultura, recreación y ocupación ilegal del territorio. Se ubicó una estación de muestreo a 1 173 m.s.n.m. (E1), con vertimientos de agua residual doméstica. La segunda a 1 069 m (E2) se ubicó antes de la bocatoma del acueducto, y la tercera a 1 019 m (E3) después de la bocatoma. Se midieron las concentraciones de variables fisicoquímicas (n = 15). Los organismos fueron recolectados usando redes surber (0.36 m2, 500 µm), de pantalla (1.6 m2, 350 µm) y D-net (0.9 m2, 500 µm), evaluando la estructura del ensamblaje mediante categorías de abundancia. El ensamblaje de macroinvertebrados acuáticos se relacionó con las variables fisicoquímicas mediante un análisis de correspondencia canónica (ACC). Las variables fisicoquímicas mostraron que E3 fue la estación más contaminada. Se registraron 9 órdenes, 23 familias y 31 taxa. E3 presentó la menor riqueza y en E2 Rhagovelia fue dominante. El ACC mostró que las variables que mayor influencia tienen sobre el ensamblaje de macroinvertebrados son el oxígeno, la DBO5, los sólidos disueltos totales y la turbidez. Se concluye que la diversidad de macroinvertebrados acuáticos disminuye con el aumento de la materia orgánica posiblemente debido a los vertimientos residuales y disminución del caudal.

Because of the influence of different human activities, rivers and their associated biodiversity are under stress. The aim of this study was to evaluate the diversity of aquatic macroinvertebrates of the Jordán River and its relation to water quality. Mining, water harvesting, livestock, agriculture, recreation and illegal occupation of the territory; take place in the evaluated section (5 650 m). A sampling site was established at 1 173 m.a.s.l. (E1), here the river receives wastewater. The second, at 1 069 m.a.s.l. (E2) was set up before the intake of an aqueduct. And the third, at 1 019 m.a.s.l. (E3) after the inlet pipe. Concentrations of physicochemical variables (n = 15) were measured. Aquatic macroinvertebrates were collected in gravel, pebbles and macrophytes using Surber nets (0.36 m2, 500 µm), a screen net (1.6 m2, 350 µm) and a D-net (0.9 m2, 500 µm). The assemblage structure was assessed using abundance categories. The diversity of aquatic macroinvertebrate and physicochemical variables were associated using canonical correspondence analysis (CCA). The physicochemical variables showed that E3 was the most contaminated site. There were 9 orders, 23 families and 31 taxa. E3 had the lowest richness and in E2 Rhagovelia was dominant. The CCA showed that variables that have the greatest influence on the diversity of macroinvertebrates are oxygen, BOD5, Total Dissolved Solids (TDS) and turbidity. It is concluded that the diversity of macroinvertebrates decreases with increasing organic matter possibly due to sewage and flow decrease.

Modelagem da progressão da DBO obtida na incubação de esgoto doméstico sob diferentes temperaturas / Modeling of BOD progression obtained in sewage incubated under different temperatures

RESUMO Confiável quantificação da demanda bioquímica de oxigênio exercida (DBO exercida) poderá ser obtida com incubação das amostras sob temperaturas diferentes, desde que o valor da demanda bioquímica de oxigênio última (DBOU) não seja alterado nessas condições. Alguns autores têm relatado aumento no valor da DBOU com a elevação da temperatura de incubação das amostras, o que pode ser decorrente da ocorrência da nitrificação, da aclimatação diferenciada ou do mau ajuste dos modelos de progressão da demanda bioquímica carbonácea de oxigênio (DBO exercida). Neste estudo, objetivou-se avaliar o efeito da temperatura sobre a progressão da DBO exercida e o valor da DBOu em amostras de esgoto doméstico bruto, avaliando-se qual modelo melhor se ajusta aos dados obtidos. Os resultados indicaram pequena influência da temperatura de incubação das amostras nos valores da DBOU do esgoto sanitário e que os modelos de primeira e segunda ordens descreveram adequadamente a progressão da DBO exercida.

ABSTRACT Reliable quantification of biochemical oxygen demand exerted (exerted BOD) can be obtained by incubating samples at different temperatures, since the amount of ultimate biochemical oxygen demand (UBOD) does not change in these conditions. Some authors have found increased UBOD values with rise in temperature of incubating samples, which could be due to the occurrence of nitrification, the acclimatization or the inadequacy of modeling of carbonaceous oxygen demand (exerted BOD) progression. This study aimed to evaluate the effect of temperature on the progression of exerted BOD and UBOD values in samples of raw domestic sewage, checking which model best fits the data. The results indicated low influence of incubating sewage samples temperature on UBOD values, being that both models, first and second order, described properly the exerted BOD progression.

Two Rapid Ana1ysis Methods of BOD5 / 环境与健康杂志

Biochemical oxygen demand of 5 days (BOD 5) was a very important parameter of monitoring ofwater quality. The classical method presented some shortcomings,such as complexity, long period, requirementof high technology and not promptly reflecting the pollution levels of water body, so it was of no significance fortreatment of industrial waste water. In this paper, two rapid methods for determination of BODs, raising incubation temperature and correlative estimation method, were introduced and their advantages, such as short period and simplicity of operation were verified by experiments. Modification of classical method was of certain instructive significance for the practical application to treatment of industrial waste water and forecast of pollutionlevels of water body.