Removal of Physicochemical and Microbial Impurities of Water Using Modified Homemade Filter

Background: There are many different methods, which are used to purify water. Some are conventional and expensive, while others are traditional and small scale, still having interesting results in killing pathogenic organisms and reducing the concentration of some chemicals and other impurities, especially for rural communities of developing countries who are suffering from water borne diseases. But because conventional water treatment methods are not affordable in rural communities of developing countries, other small-scale methods are needed. An experimental study was conducted to test the effect of modified homemade filter in reduction of turbidity, fecal coliform, fluoride and its effect on pH and temperature. Method And Materials: Representative water samples were taken from’ kochi’ stream and laboratory analysis was done both for the raw water samples and the filtrates in school of environmental health laboratory, Jimma University. Filter tanks fitted with half-inch pipe were constructed and filled with stone (10 cm), gravel (9 cm), sand (40 cm) and crushed brick (10 cm) for fluoride test and local charcoal (10 cm), instead of the crushed brick for physical and biological test. Filter tanks without crushed brick, and without local charcoal were used as control. For the determination of fecal coliform, pH and temperature, turbidity and fluoride, MPN technique, pH meter, turbidimeter and Alizarin spectrophotometry method were used, respectively. Results: With a flow rate adjusted initially to 0.35 L/min the test resulted an average concentration of fluoride 1.42 mg/l (71.6%) from 5mg/l after filtered in a Modified Homemade Filter (MHMF1) with crushed brick. After a month operation the MHMF2 (with local charcoal) reduced the faecal coliform to 1 /100ml (99.95%) and turbidity to 0.13 FTU (99.83%), which was improved as the time of filter run increased and the flow rate decreased. CONCLUSION: The study showed that filtration of raw, fluoridated water with the study media could remove physical, chemical and biological impurities up to significant values for developing countries. The filter unit is very light in weight for easy transportation and costs 210 Ethiopian Birras of March 2004. Communities who have no access for treated water supplies can have this method as alternative, appropriate and cost effective technology with careful handling and timely cleaning.Ethiop J Helath Sci. Vol. 16, No.2 July 200

Indoor air bacterial load and antibiotic susceptibility pattern of isolates at Adare General Hospital in Hawassa, Ethiopia

BackgroundAir is the agent of pathogenic microbes that cause significant problems in the hospital environment. Multidrug resistance poses a major therapeutic challenge to these airborne microorganisms in hospital indoor environments.Method and materialsThis study was conducted at Adare General Hospital in Hawassa City, Sidama, Ethiopia. A cross-sectional study was conducted. The proportional allocation method was used to select the sampled 50 rooms from the total available rooms in each category of wards and staff offices. A total of 100 indoor air samples were collected using settle plates in all units twice a day, morning (9:00–4:00 a.m.) and afternoon (3:00–4:00 p.m.). The types and number of colonies were determined in the laboratory, and the pathogenic bacteria were isolated by appropriate bacteriological techniques. Antimicrobial susceptibility testing was performed on Mueller-Hinton agar for each potentially pathogenic bacterium isolated. For each bacterium, a total of 12 antibiotics were tested using the Kirby-Bauer disk diffusion method. The test organism was adjusted to McFarland turbidity standards of 0.5. Data were entered and analyzed using the SPSS version 25 window. Descriptive analysis and one-way analysis of variance were performed.ResultsThe indoor air bacterial load of Adare General Hospital was found in the range between 210 and 3,224 CFU/m3. The highest indoor air bacterial load was identified from the gynecology ward with a mean of 2,542.5CFU/m3 at p < 0.05. From 100 indoor air samples, a total of 116 bacterial pathogen isolates were obtained. Gram-positive isolates predominated at 72.4%, of which 37.1% were Staphylococcus aureus, 26.7% were coagulase-negative Staphylococci, and the rest 8.6% were Streptococcus pyogenes. The isolation of pathogenic bacteria Staphylococcus aureus and coagulase-negative Staphylococci showed a high level of resistance to ampicillin.ConclusionA high bacterial load was found in the study area as compared to different indoor air biological standards. Staphylococcus aureus and coagulase-negative Staphylococci were the isolated predominant bacteria. Attention should be given to preventing and minimizing those environmental factors that favor the multiplication of bacteria in the indoor environment of a hospital for the safe health of patients, visitors, and staff

Chromium Remediation from Leather Tanneries

The use of leather articles is growing worldwide from time to time. Due to this leather tanning becomes an important manufactoring for economy of developing. However leather tanning causes environmental and human health problems due to the chromium mainly used for the tanning process. The main aim of this project is to reduce chromium pollution to the environment from tanneries. The study will focus on reducing the amount of chromium discharged from tanneries by increasing the chromium uptake on the leather. By applying ultrasound technology during chrome tanning process the diffusion problem of the tanning process by reducing the mass transfer boundary and increasind diffusion. This will also has an economical benefit by decreasing the cost to be invested on chromium and increasing the quality of the leather product as well. Moreover, the project is also focused on finding a low cost, locally available adsorbent to remove the possibly oxidized chromium leftover from the waste stream by using ultrasound.Table of Contents Acknowledgement V Abstract VII Samenvatting XI 1. Introduction - 1 - 1.1 History of leather making - 1 - 1.2 Current leather making in Ethiopia and its challenges - 1 - 1.2.1 Chromium uptake - 2 - 1.2.2 Chromium removal - 3 - 1.3 Research objectives - 4 - 1.4 Thesis outline - 5 - 1.5 References - 6 - 2. A review of chromium remediation options for leather tanneries - 9 - Abstract - 9 - 2.1 Introduction - 10 - 2.2 The leather tanning process - 11 - 2.2.1 Pre-tanning [beamhouse operation] - 12 - 2.2.2 Tanning [Treatment process] - 14 - 2.2.3 Finishing - 16 - 2.3 Chromium and chrome tanning chemistry - 17 - 2.3.1 Chromium chemistry - 17 - 2.3.2 Chrome tanning chemistry - 21 - 2.4 Chromium remediation options - 23 - 2.4.1 Source reduction - 23 - 2.4.2 Toxicity reduction - 27 - 2.4.3 Recovery and separation - 30 - 2.5 Conclusion - 44 - 2.6 References - 45 - 3. Impact of tannery effluent on the self-purification capacity and biodiversity level of a river - 59 - Abstract - 59 - 3.1 Introduction - 60 - 3.2 Method and Materials - 61 - 3.3 Results and Discussion - 64 - 3.4 Conclusion - 68 - 3.5 References - 69 - 4. Ultrasound assisted chrome tanning: towards a clean leather production technology - 73 - Abstract - 73 - 4.1 Introduction - 74 - 4.2 Material and Methods - 77 - 4.2.1 Experimental setup - 77 - 4.2.2 Analysis methods - 79 - 4.3 Results and discussion - 81 - 4.3.1 US before tanning - 81 - 4.3.2 US during tanning - 87 - 4.4 Conclusion - 93 - 4.5 References - 93 - 5. Effect of ultrasound on adsorption-desorption efficiency of Cr(VI) from skin powder: from a waste treatment to a clean production technology - 97 - Abstract - 97 - 5.1 Introduction - 98 - 5.2 Materials and methods - 101 - 5.2.1 Adsorbent preparation - 101 - 5.2.2 Experimental setup - 102 - 5.2.3 Adsorbent characterization - 105 - 5.3 Result and discussion - 111 - 5.3.1 Characterization of the adsorbents - 111 - 5.3.2 Effect of pH - 114 - 5.3.3 Effect of contact time - 116 - 5.3.4 Effect of adsorbent dose - 117 - 5.3.5 Adsorption isotherm and kinetic models - 118 - 5.4 Test using synthetic wastewater - 125 - 5.5 Desorption study - 127 - 5.6 Conclusion - 132 - 5.7 References - 133 - 6. Cost-benefit analysis on the use of ultrasound in chrome tanning and chromium remediation processes - 141 - Abstract - 141 - 6.1 Introduction - 142 - 6.2 Method and materials - 144 - 6.2.1 Process description - 144 - 6.2.2 US in chrome tanning - 144 - 6.2.3 US in adsorption - 144 - 6.2.4 Measurement and indicators - 145 - Direct costs and benefits - 145 - Indirect costs and benefits - 145 - 6.3 Result and discussion - 147 - 6.3.1 Costs and benefits of US tanning - 147 - 6.3.2 Costs and benefits of US adsorption - 152 - 6.4 Conclusion - 155 - 6.5 References - 155 - 7. Conclusions and future perspectives - 157 - 7.1 Conclusions - 157 - 7.2 Future perspectives - 161 - List of publications and CV - 163 -status: publishe

Ultrasound assisted chrome tanning: Towards a clean leather production technology

Nowadays, there is a growing demand for a cleaner, but still effective alternative for production processes like in the leather industry. Ultrasound (US) assisted processing of leather might be promising in this sense. In the present paper, the use of US in the conventional chrome tanning process has been studied at different pH, temperature, tanning time, chrome dose and US exposure time by exposing the skin before tanning and during tanning operation. Both prior exposure of the skin to US and US during tanning improves the chrome uptake and reduces the shrinkage significantly. Prior exposure of the skin to US increase the chrome uptake by 13.8% or reduces the chrome dose from 8% to 5% (% based on skin weight) and shorten the process time by half while US during tanning increases the chrome uptake by 28.5% or reduces the chrome dose from 8% to 4% (half) and the tanning time to one third compared to the control without US. Concomitantly, the resulting leather quality (measured as skin shrinkage) improved from 5.2% to 3.2% shrinkage in the skin exposed to US prior tanning and to 1.3% in the skin exposed to US during the tanning experiment. This study confirms that US chrome tanning is an effective and eco-friendly tanning process which can produce a better quality leather product in a shorter process time with a lower chromium dose.publisher: Elsevier articletitle: Ultrasound assisted chrome tanning: Towards a clean leather production technology journaltitle: Ultrasonics Sonochemistry articlelink: http://dx.doi.org/10.1016/j.ultsonch.2016.03.002 content_type: article copyright: © 2016 Elsevier B.V. All rights reserved.status: publishe

Impact of tannery effluent on self-purification capacity and biodiversity level of rivers

This research investigates the impact of tannery effluent on the self purification capacity of natural streams by biodegradation and on sustaining macroinvertebrates. Water samples were collected from upstream (US) and downstream (DS) of the discharge point of four tanneries along the course of the Tinishu Akaki river (Ethiopia) for physicochemical parameters and macroinvertebrate analysis. As the concentration of chromium and sulfide increases from US to DS of the river, the removal of SS (Suspended Solids), and reduction of BOD5 (Biological Oxygen Demand) and COD (Chemical Oxygen Demand) by the self purification process decreases from 71%, 59% and 50%, respectively, to 10%, 30% and 28%, respectively, while also the nitrification capacity becomes severely hampered. The macroinvertebrate %EPT (ratio of total number of individuals classified as Ephemeroptera, Plecoptera, and Trichoptera to the total number of individuals), which is a measure of the presence of pollution sensitive macroinvertebrates decreased from 24% to zero, starting downstream from the third tannery, indicating severe pollution. The diversity index and correlation values between the concentration of physicochemical parameters, BOD5 reduction, the macroinvertebrate count and the chromium concentration further support these findings. The conclusion from this study is that, although the physicochemical parameters might indicate that, given enough distance between the tanneries, self recovery of the river can be gained for a while, the biodiversity and general health of the river is severely compromised such that aquatic life can hardly be sustainedstatus: accepte

Impact of Tannery Effluent on the Selfpurification Capacity and Biodiversity Level of a River

The present study investigates the impact of tannery effluents on the self-purification capacity and the local macroinvertebrate community of one natural stream. As the concentration of chromium and sulfide increased from up- to downstream sites, the reduction of suspended solids, 5-days biological oxygen demand (BOD5), chemical oxygen demand and nitrification capacity decreased by 61 %, 21 %, 30 % and 74 %, respectively. Similarly, the share of Ephemeroptera, Plecoptera, and Trichoptera on the macroinvertebrate community decreased from 24 % to 0 %. Also the diversity (Simpson’s) index and the correlation between the physicochemical parameters, BOD5 reduction, the macroinvertebrate abundance and the chromium concentration underpin the importance of the contamination by tannery effluents for the degradation of the stream habitat quality. In conclusion, although the physicochemical parameters indicate that the self-purification of the river can be maintained for a certain stream section, the biodiversity of the river is severely compromised.status: publishe

Mental health of healthcare professionals during the early stage of the COVID-19 pandemic in Ethiopia

Background The coronavirus (COVID-19) pandemic causes healthcare professionals to suffer mental health problems such as psychological distress, anxiety, depression, denial and fear. However, studies are lacking related to Ethiopia and to Africa in general. Aims To study the mental health of healthcare professionals during the COVID-19 pandemic in Ethiopia. Method A hospital-based cross-sectional study was conducted at Jimma University Medical Center among 249 healthcare professionals. The data were collected using self-administered questionnaires between 22 and 28 March 2020. The psychological impact was assessed using the Impact of Event Scale - Revised (IES-R) and symptoms of insomnia were measured using the Insomnia Severity Index (ISI). Social support was evaluated using the three-item Oslo Social Support Scale. Data were analysed using logistic regression to examine mutually adjusted associations, expressed as adjusted odds ratios. The psychosocial status of the healthcare professionals was predicted using a classification tree model supported by the genetic search method. Results The prevalence of psychological distress among healthcare professionals was 78.3%. The mean IES-R score was 34.2 (s.d. = 19.4). The ISI score indicated that the prevalence of insomnia was 50.2%. Higher psychological distress was associated with younger age, having insomnia, not having a daily update on COVID-19, and feeling stigmatised and rejected in the neighbourhood because of hospital work. Conclusions This study indicates that, in Ethiopia, the prevalence of psychological distress among healthcare professionals is high and associated with specific sociodemographic risks

The contents of essential and toxic metals in coffee beans and soil in Dale Woreda, Sidama Regional State, Southern Ethiopia

Background For developing countries such as Ethiopia, coffee is a commodity of great economic, social, and environmental importance. No detailed investigations have been performed on the contents of essential and toxic metals in coffee beans and soil in this study area. Methods The levels of essential metals (Na, K, Ca, Zn, Mn, Cu, Co, Cr, Ni) and toxic elements (Pb and Cd) were investigated in coffee beans (coffee growing farmland and coffee washed plants) and soil samples (from farmland) using flame atomic absorption spectrometry (FAAS) and flame emission atomic spectroscopy. We selected six (20%) administrative units (kebele) with purposive sampling techniques based on their coffee production capacity in Dale Woreda for soil testing. After coffee sample preparation in a microwave system with HNO3and H2O2 reagents, the accuracy of the optimized procedure was evaluated by analysing the digest of the spiked samples. Soil samples were abridged with a slight revision of the EPA 3050B acid digesting method. ANOVA was used to determine the significant differences in the mean concentration of metal within coffee beans from farmland at the various sampled sites at the p Na>Ca >Mn>Cu> Ni>Zn. Metal levels were found to be K>Na>Ca >Mn>Cu> Zn>Ni in coffee beans from the washed plants. Co, Cr, Pb and Cd were no detected in all coffee bean samples. Except for calcium, potassium and manganese, the levels of metals in coffee beans from farmland and washed plants were not significantly different at the 95% confidence level within a kebele. Conclusions We observed permitted levels of macro- and trace elements in coffee beans from farmlands and washed plants. Only in the soil samples are cadmium concentrations higher than those permitted for agricultural soil recommended by the WHO and FAO. Overall, there is no health danger linked with the use of coffee beans due to detrimental and trace heavy metals

Challenges to surface water quality in mid-sized African cities: conclusions from Awetu - Kito rivers in Jimma, SW Ethiopia

Rapid urbanization and industrialization, uncontrolled population growth, indiscriminate waste discharge and poor infrastructure are problems that African cities are facing. This paper describes an exemplary case study from Jimma, south-west Ethiopia. A cross-sectional study was conducted along the Awetu-Kito drainage system in Jimma town to assess the level of pollution from urban dwellers and related activities. The study indicates that the Environmental Protection Agency (EPA) norms for biochemical oxygen demand (BOD), dissolved oxygen (DO) and orthophosphates are not met downstream of the major industrial and institutional activities. Small-scale industries, Jimma University and residential areas contributed 50, 15 and 23% pollution load on the river, respectively. It can be concluded that the pollution effect in Jimma town is mainly as a result of the growing (uncontrolled) industrial activities and not to discharge of household wastewater. Given the same trends of urbanization and population growth, similar development (socio-economic) indicators and similar climatic conditions, the key findings for Jimma are transferable to other mid-sized African cities. © 2012 CIWEM.status: publishe

Traditional Medicinal Plants

Despite recent scientific advancement and globalization, the system of traditional medicine and complementary/alternative medicine is considered as a primary health care modality in the resource-constrained health care settings. Herbal medicinal system has been postulated and established through empirical observation and trial and error experiments since time immemorial to maintain good health and alleviate ailments and diseases. Earlier, the importance of traditional medicinal plants and phytotherapy have often been disregarded and undervalued. Presently revitalization and renewed interest on traditional medicinal plants has been observed among the public and scientific community. However, several daunting challenges need to be flagged effectively and immediately for the promotion of traditional medicinal plants. The collaborative efforts of ethnobotanists, anthropologists, pharmacists, and physicians could be a workable strategy to evaluate and validate the usage of traditional medicinal plants with the modern scientific methods and innovative techniques. Furthermore, conducting clinical trials to assess their efficacy and human safety is imperative and inevitable