Synthetic colorants used for dye and mordant purposes in textile industries are currently causing environmental problems in the world. The usage of these synthetic colorants is a major health problem ...and harms the environment. For this reason, synthetic colorants should be replaced by natural colorants. Therefore, this study aimed to extract natural dye stuff from spent coffee ground and bio-mordant from mango bark. The raw materials were collected, washed, dried, crushed and their physico-chemical properties were determined. Finally, the samples were extracted by using the solvent extraction method. During the extraction process, the central composite design method (CCD) was used to analyze and optimize the effect of dosage (g/l), temperature (℃) and time (min). The maximum natural dye yield value of 18.41% was obtained at a dosage of 60 g/l, temperature of 70°C and time of 90 min. Also, the highest natural mordant yield of 19.03% was achieved at the value of 45 g/l, 70°C and 90 min. The fastness properties of dyed and mordanted cotton fabric results were within a range of acceptable standard values. Therefore, using spent coffee grounds for natural dyes and mango bark for natural mordant can be a feasible commercial alternative to synthetic dyes in textile and dyeing industries.
Background
Vegetables grown at contaminated sites can take up and accumulate toxic and potentially toxic elements at concentrations that are toxic to human health. The present study determined the ...levels of potentially toxic elements/PTEs in irrigation water, soil and vegetable samples grown along contaminated river and assessed the potential health risks to consumers.
Results
The average concentrations of Mn, Sr and Cr in the irrigation water were higher than the international guideline values. The levels of As, Cr, B and Ni in most of the farm soils were also found to be higher than the guideline values. Other PTEs, although not exceeding the recommended limits were relatively high in the soil and water samples. The study also revealed that the mean levels of Cr, Cd and Fe in most vegetables were higher than the maximum recommended limits. Swiss chard was maximally contaminated with PTEs followed by lettuce, cabbage, Ethiopian kale, carrot and potato. Hence, frequent consumption of lettuce and Swiss chard may cause serious health risks to consumers.
Conclusion
The levels of many elements were varied with location, suggesting localized inputs of the various contaminants related to industrial and other activities that generate wastewater.
The Akaki River and its tributaries, in the city of Addis Ababa, are polluted by potentially toxic elements (PTEs) (Sb, Zn, Cd, As, Hg, Cu, Pb, Fe, V, Ni, Co, Mn, Cr, B, Sr and Ba) in varying degrees ...due to the significantly fast urban expansion and the industrial activities. The water samples collected from twenty-six different locations or sampling sites along the River and some of its tributaries were analyzed by ICP-MS to determine PTEs. The multivariate component analysis was used to evaluate the relationship and interdependency among the PTEs. The results showed that the mean concentrations for most of PTEs exceeded the recommended limits of drinking and irrigation water quality guidelines. A strong and positive relationship was observed among many of PTEs in the river water indicating common sources. The concentrations of many PTEs in the study area exceeded those previously reported and also varied with site or location, signifying localized contributions of the different contaminants associated with municipal, domestic, industrial, hospitals, garages and other activities. These findings of this study should help highlight and focus water quality management on key PTEs of concern and prioritize efforts to mitigate their release into surface waters in the city. Given the potential health implications of the PTEs mitigation measures should be sought as a matter of urgency by the relevant authorities in Ethiopia.
Rapid urbanization, industrialization and population growth pose major threats to the ambient water quality, indicator 6.3.2 of the United Nations Sustainable Development Goal (SDG) 6, in African ...catchments. One example is the catchment of the Akaki Rivers that flow through Ethiopia's capital, Addis Ababa. The objective of this study was to demonstrate a monitoring approach for assessing the physico-chemical and ecological health status of African Rivers using locally available expertise and analytical capabilities. Representative water samples were collected from twenty-three different sampling locations in the Akaki catchment for various physico-chemical measurements. A biological assessment was conducted using the mini-stream assessment scoring system (miniSASS) tool. Principal component analysis (PCA) was applied to assess variations in water quality. The study revealed notable differences in water quality between the Little Akaki River, which flows through the city center of Addis Ababa, and the Big Akaki River, which flows mostly through the peri-urban fringe of Addis Ababa. PCA revealed higher levels of water quality parameters in the Little than in the Big Akaki River. For the Little Akaki River, except for pH, all of the measured parameters had significant seasonal variation. In contrast, for the Big Akaki River, no significant seasonal variation was observed in the measured parameters. Downstream of Addis Ababa, improvement in water quality was observed to most of the measured parameters and during all of the seasons where the Akaki Rivers pass through rural areas. There were no significant correlations between physico-chemical measurements and miniSASS scores. The study thus showed that monitoring physico-chemical parameters alone may be insufficient and biological monitoring should be included. Application of these methods and analysis of the results can help catchment scale monitoring of freshwater quality on the African continent.
Due to the significantly fast urban expansion and increased industrial activities, the soils in the farms in Addis Ababa are contaminated by some toxic and potentially toxic elements (As, V, Cr, Fe, ...Co, Ni, Cu, B, Ba, Sr, Zn, Mn, Pb and Cd) in varying degrees. The mean concentrations of Cr, Ni, As and B in most of the soil farms were found to be higher than the maximum recommended limits. The mean concentrations of Cd, Cu, Pb, Co, Ni and Mn were found to be higher than the background soil concentrations given for uncontaminated soils. Multivariate analyses coupled with correlation analysis were used to identify possible sources. The geo-accumulation index values for Cr, Mn and Pb indicated that the farm soils were unpolluted to moderately polluted as a result of anthropogenic activities. A comprehensive environmental management strategy should be formulated by the government to measure further pollution of the farmland soil.
Quantification of engineered nanomaterials in the environment has attracted researchers’ interest recently because of their increased release to the environment. In this study, a recyclable and ...easily accessible magnetized coffee residue (MCR) is proposed for magnetic solid-phase extraction (MSPE) of zinc oxide nanoparticles (ZnO-NPs) from water samples. The MCR was synthesized using a simple one-step chemical co-precipitation method from coffee residue and was characterized by state-of-the-art techniques. Various parameters affecting the MSPE efficiency of ZnO-NPs were optimized and 8.5 pH, 75 mg adsorbent, 120 min extraction time, 10 mL sample volume, 4 mL of 0.001 M HCl as an eluting solvent, and 30 min elution time were identified as the optimum conditions. Under these conditions, the method showed excellent linearity (R2 = 0.995) and good sensitivity (detection limit, 0.12 mg L-1, and quantification limit, 0.4 mg L-1). Intra and inter-day percent standard deviations were 1.4 and 2.2%, respectively, for the analysis of 6 mg L-1 ZnO-NPs. The practical applicability of the method for the extraction of ZnO-NPs in environmental samples was evaluated, and recovery values in the range of 93.0–98.2% were obtained, confirming its successful performance. Generally, the technique is easy, economical, and eco-friendly that can be considered for the extraction of metal oxide nanoparticles.
KEY WORDS: Zinc oxide nanoparticles, Magnetic coffee residue, Magnetic solid-phase extraction, Flame atomic absorption spectroscopy, Environmental waters
Bull. Chem. Soc. Ethiop. 2023, 37(4), 859-873.
DOI: https://dx.doi.org/10.4314/bcse.v37i4.5
The brewery industry is known for consuming a significant amount of water during beer production and releasing large quantities of wastewater into the environment. The Harar Brewery factory generates ...a substantial amount of wastewater, which is utilized for irrigation. However, there have been no comprehensive scientific studies assessing the physicochemical and bacteriological properties of the wastewater in relation to its suitability for irrigation. Therefore, this study aimed to evaluate the physicochemical and bacteriological properties of the wastewater to determine its suitability for irrigation. The analytical procedures were conducted following the APHA procedure and the results were compared with national and international standards. Various parameters were investigated, including, temperature (25.01 °C), TDS (848.88 mg/L), TSS (256.67 mg/L), TS (1107.92 mg/L), pH (8.06), EC (1253.42 µS/cm), DO (3.96 mg/L), COD (628.34 mg/L), BOD5 (12.29 mg/L), PO43—P (0.29 mg/L), NH3N (0.65 mg/L), NO3—N (1.52 mg/L), NO2−-N, TN (2.26 mg/L), Mn (0.04 mg/L), Zn (0.03 mg/L), Fe (0.27 mg/L), Cu (0.09 mg/L), Ca (0.51 mg/L), Mg (1.12 mg/L), Na (6.59 mg/L), K (0.68 mg/L), E. coli (4491.67) and TC (14,279.17 CFU/100 mL). Most of the physicochemical parameters and coliform counts met national and international standards. However, EC, TS, TSS, BOD, and COD exceeded Ethiopian standards and international limits. Despite this, farmers continued to use the wastewater for irrigation, potentially leading to long-term adverse effects on both life and the environment. In conclusion, this study highlights the importance of implementing advanced treatments to ensure that brewery wastewater meets specific parameters for irrigation suitability.
This paper draws upon previous and current research on the levels of various pollutants in the Awash River Basin. The research used high‐tech instruments to determine the levels of physio‐chemical ...parameters, potentially toxic elements, and other pollutants in wastewater, sediment, soil, vegetables, and fish samples collected from different sampling sites in the Akaki catchment. The results showed that the average concentration for most of the analyzed parameters exceeded the recommended limits stated by drinking and irrigation water quality guidelines. The concentrations varied with the sites significantly with trends of localized contributions of the different contaminants associated with industrial, municipal, domestic, medical centers, garages, petrol stations, and other commercial centers evident. Concentrations of contaminants were remarkably high in the catchment rivers and shallow groundwater reservoirs. Comparison with permissible standards showed poor environmental management by relevant regulatory bodies and industries. Despite having good laws and standards at the federal and regional levels, they are not effectively implemented or enforced to prevent environmental pollution. Given the potential health implications of the toxic substances, we recommended a range of mitigation measures as a matter of urgency to the relevant authorities.
摘要
本文借鉴了关于阿瓦什河流域不同污染物水平的以往研究及现有研究。本研究使用高科技工具测定了从阿卡基流域不同采样点收集的废水、沉积物、土壤、蔬菜和鱼类样本中的理化参数、潜在有毒元素以及其他污染物的水平。结果表明, 大多数分析参数的平均浓度超出了饮用水和灌溉水质指南规定的建议限值。不同地点的浓度差异很大, 与工业、城市、家庭、医疗中心、车库、加油站和其他商业中心相关的不同污染物的局部贡献趋势很明显。流域河流和浅层地下水库的污染物浓度非常高。与允许的标准相比, 相关监管机构和行业的环境管理不力。尽管联邦和地区层面制定了良好的法律和标准, 但这些法律和标准并未有效实施或执行以防止环境污染。鉴于有毒物质对健康的潜在影响, 我们向有关当局建议了一系列紧急的缓解措施。.
Resumen
Este artículo se basa en investigaciones anteriores y actuales sobre los niveles de diversos contaminantes en la cuenca del río Awash. La investigación utilizó instrumentos de alta tecnología para determinar los niveles de parámetros fisicoquímicos, elementos potencialmente tóxicos y otros contaminantes en muestras de aguas residuales, sedimentos, suelo, vegetales y peces recolectadas en diferentes sitios de muestreo en la cuenca de Akaki. Los resultados mostraron que la concentración promedio para la mayoría de los parámetros analizados excedió los límites recomendados por las pautas de calidad del agua potable y de riego. Las concentraciones variaron significativamente según los sitios, con tendencias evidentes de contribuciones localizadas de los diferentes contaminantes asociados con centros industriales, municipales, domésticos, médicos, garajes, gasolineras y otros centros comerciales. Las concentraciones de contaminantes fueron notablemente altas en los ríos de captación y en los embalses de aguas subterráneas poco profundas. La comparación con las normas permitidas mostró una gestión ambiental deficiente por parte de los organismos reguladores y las industrias pertinentes. A pesar de contar con buenas leyes y estándares a nivel federal y regional, no se implementan ni se hacen cumplir de manera efectiva para prevenir la contaminación ambiental. Dadas las posibles implicaciones para la salud de las sustancias tóxicas, recomendamos una serie de medidas de mitigación con carácter de urgencia a las autoridades pertinentes.
The concentrations of toxic and potentially toxic elements (As, V, Cr, Fe, Co, Ni, Cu, B, Ba, Sr, Zn, Mn, Pb and Cd) collected from benthic sediments in the water bodies of the city of Addis Ababa ...were investigated to evaluate their distribution and pollution levels. The average concentration of Cr, Mn, Pb, Ni, Fe, Cu, Zn and Cd exceeded the threshold effect level of the sediment quality guidelines. Many of the concentrations were higher than previously reported. The sediments were moderately to heavily polluted with Cr, non-polluted to severe with Cu, Zn and Pb elements, moderate to heavily polluted with Ni and non-polluted by As and Cd. The sediments were enriched with these elements in the increasing order As<Ba<V<Ni<Cu<Cd<Co<Zn<Mn<Pb<Cr. The geo-accumulation index values for Pb, Cu, Cr and Mn indicate that at some sites unpolluted to strongly polluted. The first three principal components represented about 79% of the total variance in the sediment data sets. The significant positive correlation between elements indicates their common anthropogenic origin most likely from industrial effluents, municipal wastes and domestic wastewater inputs to the river. Since the polluted environment significantly impacts the beneficial uses of the water body and has health implication, remedial actions (e.g. capping or removal of the sediments) need to be considered. A comprehensive environmental management strategy should be formulated to address the pollution of the sediments. In parallel, there should be a strict prohibition of discharges of contaminated wastewater into the river.
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