Groundwater quality assessment of Chilanchil Abay watershed: the case of Bahir-Dar City waste disposal site

Improper dump sites have served many years as an ultimate disposal site for all types of waste; municipal solid waste, industrial sewage and hazardous waste in developing countries such as Ethiopia. Physical, chemical and biological processes interact simultaneously to bring about the overall decomposition of the wastes (chemically laden leachate).  If not, deal properly, such kind of dumping site can cause pollution to groundwater (because of Leachates) and surface water (through contaminant transportation by flooding and groundwater movements). Therefore, this study investigates the spatial and temporal variation of groundwater quality within the Chilanchil Abay watershed during dry and wet season due to the waste disposal site of the Bahir Dar city. Water samples were collected from 6 sampling points of groundwater from 30th March to 20th August by a monthly period. Over 10 water quality parameters such as pH, TDS, Electrical conductivity, Turbidity, Temperature, DO, BOD, COD, TC, NO3- and PO43–, were analyzed. Moreover, the overall status of the groundwater quality of the study area was evaluated by the Canadian Water Quality Index. Based on the result of this model the status of the groundwater sample points throughout the study area were raged from 42 to 46.2 (marginal status)

Major Insect Pests and their Associated Losses in Quantity and Quality of Farm-Stored Wheat Seed

አህጽሮትበተከዘነ ስንዴ ላይ በጎተራ ነፍሳት ሰበብ ጉልህ ብክነት ይደርስ ወይም አይደርስ እንደሆነ ብዙ ክርክር አሇ፡፡ የችግሩን አገር አቀፋዊ ይዘት ሇመረዳት ከአማራ፣ ከኦሮሚያ፣ ከደብብህ፣ እና ከትግራይ ክልሎች በተመረጡ አምስት የስንዴ አብቃይ ወረዳዎች ላይ የስንዴ ናሙናዎችን ከአርሶ አደር መጋዘኖች በመሰብሰብ የዳሰሳ ጥናት እ.አ.አ. በ2016 በሰኔ ወር ተከናውኗል፡፡ ከእናንዳንዱ አርሶ አደር ቤት አንድ ኪሎግራም በመውሰድ በድምሩ 150 ናሙናዎች ተሰብስበው ተፈትሸዋል፡፡ ከናሙናዎቹ ላይም የጎተራ ነፍሳት አይነቶች፣ በነፍሳት ምክንያት የደረሰ የክብደት መቀነስ በመቶኛ፣ በነፍሳት ምክንያት የደረሰ የመቦርቦር ችግር እና በመጨረሻም የዘር ብቅሇት ደረጃ መረጃዎች ተሰብስበው ተተንትነዋል፡፡ በተገኘው መረጃ መሰረት ከስድስት ያላነሱ የጎተራ ነፍሳት አይነቶች የታዩ ሲሆን በነፍሳት የተበሳ/የተቦረቦረ የስንዴ ፍሬ ቁጥር በየወረዳው በአማካይ በመቶኛ ከ3.6 እስከ 13.6 መሆኑ ታይቷል፡፡ በተመሳሳይ መልኩ በነፍሳት ምክንያት በዘር ላይ የደረሰ የክብደት መቀነስ በየወረዳው በአማካይ በመቶኛ 1.5 ነበር፡፡ በተጨማሪም አማካይ የዘር ብቅሇት በአማካይ በመቶኛ 72.3 ብቻ ሆኖ ታይቷል፡፡ በአሁኑ የዳሰሳ ጥናት ውጤት መሠረት በአርሶ አደሮች በተከዘነ የስንዴ ዘር ላይ በጎተራ ነፍሳት ምክንያት የሚደርሰው ጉዳት በዓይነትም በጥራትም ረገድ ከተጠበቀው በላይ መሆኑን ሇመረዳት ይቻላል፡፡ ስሇዚህም አግባብነት ያላቸው የተከዘነ ስንዴ መጠበቂያ አሰራሮች ሇአርሶ አደሮች መተዋወቅና በክዘና ደረጃ የሚደርሰውን ብክነት የመቀነስ ሥራ መሠራት አሇበት፡፡AbstractThere is considerable debate over the importance of losses associated with insect pests of stored wheat at the farm level in Ethiopia. A survey was conducted to assess the most significant insects and losses of farm-stored wheat in five districts in Amhara, Oromiya, Southern Nations, Nationalities and Peoples, and Tigray regional states of Ethiopia during 2016. One kg samples of stored wheat seed were collected over a period of eight months from 150 farmers. The samples were kept in the laboratory for approximately six weeks to allow the population of insects present to develop and emerge as adults. After adult emergence, the resultant weight loss, seed damage, and loss of seed germination were determined. Major primary insect pests identified were the granary weevil, Sitophilus granarius, Sitophilus spp., and the Angoumois grain moth, Sitotroga cerealella. Secondary pests such as Tribolium spp., the India meal moth, Plodia interpunctella, and Liposcelis spp. were detected in a few samples. Wheat experienced mean percentage kernel damage that ranged from 3.6 to 13.6%. Mean weight loss due to insects was 1.5%, while mean seed germination was only 72.3%. The present survey indicated that farmers are incurring a considerable loss in the quantity and quality of stored wheat due to insects. Hence, there is an urgent need to devise appropriate tactics for protecting the losses in farm-stored wheat in Ethiopia

Mortality of Sitophilus granarius (L.) and Rhyzopertha dominica (F.) Adults Exposed to Different Concentrations of Filter Cake in Stored Wheat

አህፅሮትየሲልከን ውሁድ ያሊቸው ግዑዝ ብናኞች የተከዘነ እህልን ከጎተራ ነፍሳት ከመከሊከል አንጻር ከኬሚካሎች ይልቅ ሇአካባቢ ተስማሚ ሇጤናም ጉልህ ጉዳት የማያስከትለ አማራጮች እየሆኑ መጥተዋል፡፡ ከዚህ ጋር ተያይዞ አንድ የሲሉከን ውሁድ ያሇው የማጣሪያ ኬክ ብናኝ በጎተራ ነፍሳት ሊይ የሚኖረውን የመቆጣጠር አቅም ሇመፈተሽ በጎተራ ነቀዝ እና በትንሹ እህል ቦርቧሪ ጥንዚዛ ሊይ ጥናት ተደርጓል፡፡ ጥናቱ የተከናወነው 1ኪ.ግ.፣ 0.75ኪ.ግ.፣ 0.5ኪ.ግ.፣ እና 0.25ኪ.ግ. የማጣሪያ ኬክ ብናኝ በአንድ ኩንታል ስንዴ ሊይ በመጨመር ሲሆን የብናኙን ውጤታማነት ሇመቆጣጠር ምንም ብናኝ ያልተደረገበት ስንዴ ከጎን ተጠንቷል፡፡ ጥናቱ ባጠቃሊይ ሇ14ቀናት የተከናወነ ሲሆን ብናኝ ባሇው ስንዴ ውስጥ የገቡ ጉልምስ ነፍሳት የደረሰባቸው የሞት መጠን ተገምግሟል፡፡ በዚህም መሠረት በጎተራ ነቀዞች ሊይ በሶስት ቀናት ብቻ ከ41.3% እስከ 70.0% የጉልምሶች ሞት የተከሰተ ሲሆን ይህ በትንሹ እህል ቦርቧሪ ጥንዚዛ ጉልምሶች ሊይ ከ73.3% እስከ 93.3% ሞት አስከትሏል፡፡ ከ14 ቀናት በኋሊ ሲታይ በጎተራ ነቀዝ ጉልምሶች ሊይ እስከ 98.7% ሞት ያስከተሇ ሲሆን በትንሹ እህል ቦርቧሪ ጥንዚዛ ሊይ ግን እስከ 100% ሞትን አስከትሏል፡፡ ስሇዚህ በዚህ ጥናት ሊይ የተካተቱ የነፍሳት ዝሪያዎችን በማጣሪያ ኬክ ብናኝ ከሞሊጎደል መቆጣጠር እንደሚቻል መመልከት ይቻሊል፡፡AbstractSilica based inert dusts are eco-friendly alternatives to control stored grain insect pests due to environmental and health concerns associated with use of synthetic insecticides. A study was conducted to determine the efficacy of filter cake (a silica-based inert dust) on the granary weevil, Sitophilus granarius (L.) and lesser grain borer, Rhyzopertha dominica (F.) in stored wheat. Filter cake dust of ≤0.4 mm particle size was admixed with 500 g of wheat seed to provide nominal rates of 10000, 7500, 5000, and 2500 ppm (mg/kg), while the control treatment consisted of wheat seeds that were untreated. The bioassays were carried out using a liter-sized plastic jars in completely randomized design with three replications. Experiments were maintained at 23.1±1.7oC and 61.0±4.3% relative humidity. Mortality data were collected at 3, 7, and 14 d after treatment. Results indicated that mean mortality rate at 3 d after treatment ranged from 41.3 to 70.0% in S. granarius and 73.3 to 93.3% in R. dominica. Mean mortality of S. granarius adults at 14 d in filter cake treatments was 84.0 to 98.7%, whereas that of R. dominica was 98.3 to 100%. The present results show that filter cake dusts can be used to control these two species in stored wheat. Filter cake has potential in protection of wheat from S. granarius and R. dominica infestations in storage

Occurrence of Mycotoxins in Stored Maize in Ethiopia

አህጽሮትበእህል ላይ በሚከሰቱ ሻጋታዎች ምክንያት የሚፈጠሩ መርዛማ ኬሚካሎች ሇምግብ ደህንነት፣ ሇምግብ አቅርቦትና ሇድንበር ተሻጋሪ የንግድ ሥርዓት ስጋት በመሆናቸው አሇምአቀፍ ትኩረት እየሳቡ ይገኛለ፡፡ በአገራችን የበቆሎ ምርት ላይ ያሇውን የእነዚህ መርዛማ ኬሚካሎች ክስተት ሇማጥናት ከአምስት የበቆሎ አምራች ወረዳዎች ከተውጣጡ አርሶ አደሮች ቤቶች የተሰበሰቡ 150 ናሙናዎች ላይ ፍተሻ ተደርጓል፡፡ በጥናቱ አራት ዓይነት ሻጋታ ወሇድ መርዛማ ኬሚካሎች የተገኙ ሲሆን ከእነዚህ ውስጥ አፍላቶክሲን የተባሇው መርዛማ ኬሚካል መጠኑ ቢሇያይም በሁለም ናሙናዎች ላይ ተገኝቷል፡፡ ስሇሆነም የእነዚህን ሻጋታ ወሇድ መርዛማ ኬሚካሎች ክስተት ሇመከላከል በአርሶ አደሮች ደረጃ አስፈላጊው የድህረ ምርት ክብካቤ እርምጃ መወሰድ አሇበት፡፡AbstractMycotoxins are attracting worldwide attention because of their implications for food safety, food availability, and international trading. A study was conducted to determine mycotoxin occurrences in stored maize in 150 samples collected from five major maize growing districts of Ethiopia: namely, Mer-Awi, Wenberma, Chelia, Halaba, and Toke Kutaye. Total aflatoxins (AFT), total fumonisins (FUM) and deoxynivalenol (DON) were measured using lateral flow immunoassay whereas the Enzyme-Linked Immunosorbent Assay was used for ochratoxin A (OTA). Results indicated that incidences of AFT, FUM, OTA, and DON were 100, 32.7, 24, and 7%, respectively (N=150). The average level of AFT was 14.7±11.6 ng/g ranging between 6.3 ng/g to 150 ng/g. Incidences of safe levels of AFT were 94.6%, 11.3%, and 0% when evaluated by the maximum tolerable level (MTL) of Food and Drug Administration (FDA), East African Community (EAC), and the European Commission, respectively. The average level of FUM in positive samples was 0.68±0.94 μg/g with a range between 0.2 μg/g and 6.52 μg/g. OTA positive samples had an average level of 8.2±30.6 ng/g and a range between 2 ng/g and 186.5 ng/g. Likewise, the average and range of DON in positive samples were 0.65±0.46 μg/g and 0.27−1.98 μg/g, respectively. Co-occurrences of mycotoxins were observed, and AFT-FUM co-occurrence incidence was the highest of all others (32.7%, N=150). The occurrence of mycotoxins in stored maize in Ethiopia is evident from the survey result

Optimization of process parameters for the synthesis of geopolymer binders

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Catalytic wet air oxidation of phenol over active carbon in fixed bed reactor: steady state and periodic operation

The fast world industrialization and urbanization creates a large number of water pollutants that are toxic and hazardous and in most cases too hard to amend naturally. Phenols are amongst those toxic compounds frequently found in many industrial effluents. A review of the specific literature points out that catalytic wet air oxidation using activated carbon can be a promising solution for the destruction of phenolic pollutants. However, it seems unlikely to achieve stable catalyst in fixed bed reactor under steady state operation due to the slow combustion of activated carbon. Within this context, the present work focus on three main aspects to extend the current state of art of catalytic wet air oxidation: establishing reactor start-up, kinetic measurements and periodic operation of fixed bed reactors. It has been shown that kinetic measurement can be conducted in trickle bed reactor without mass and heat transfer limitations. Most importantly, stable catalyst during catalytic wet air oxidation of phenol over active carbon was achieved in fixed bed reactor through dynamic reactor operation by optimizing periodic parameters.La rápida industrialización y urbanización mundial ha creado un sin número de contaminantes para los medios acuosos tóxicos y peligrosos, los cuales en su gran mayoría son difícil de degradar de forma natural. Los fenoles son algunos de estos compuestos tóxicos que se encuentran con frecuencia en muchos efluentes industriales. Revisión literaria específica que la oxidación catalítica en aire húmedo utilizando carbón activado podría ser una solución prometedora para la destrucción de estos contaminantes fenólicos. Sin embargo, parece difícil lograr la estabilidad del catalizador dentro del reactor de lecho fijo, en estado estacionario, debido a la combustión lenta de carbón activado. Dentro de este contexto, el presente trabajo se centró en tres aspectos principales para extender los conocimientos actuales sobre la oxidación catalítica del aire húmedo, los cuales son: el establecimiento de las condiciones de arranque del reactor, el estudio de la cinética de reacción y la evaluación de la operación periódica de reactores de lecho fijo. Se ha demostrado que la cinética de la reacción puede llevarse a cabo en un reactor por goteo de lecho fijo sin limitaciones de transferencia de masa y calor. Y más importante aún, el catalizador pudo mantenerse estable durante la oxidación catalítica del aire húmedo de fenol sobre carbón activo en un reactor de lecho fijo, a través de la operación de un reactor dinámico mediante la optimización de los parámetros periódicos

Synthesis and Characterization of 5-Hydroxymethylfurfural from Corncob Using Solid Sulfonated Carbon Catalyst

5-Hydroxymethylfurfural as a versatile organic compound is considered as a promising biomass-derived product via hydrolysis followed by dehydration of lignocellulosic biomass using solid catalysts. In this study, lignocellulosic materials (corncob) were utilized to synthesize 5-hydroxymethylfurfural via solid acid catalytic conversion. The precursor of the catalyst material was chemically impregnated with ZnCl2 prior to carbonization. The solid catalyst was prepared with three different acid concentrations of 98%, 96%, and 94% of sulfuric acid. The prepared catalyst was characterized by acid density elemental analysis, FTIR, XRD, and SEM. The maximum result of the total acid density and amount of SO3H group was recorded as 3.5 mmol/g and 0.61 mmol/g, respectively, with high sulfur content of 1.87%. The result from FTIR spectra of BC-SO3H−1 confirms the incorporation of -SO3H groups into the carbon material. BC-SO3H−1 was selected based on the acid density and elemental analysis of the catalyst. The activity of the selected catalyst (BC-SO3H−1) was studied on the transformation of corncob to 5-hydroxymethylfurfural using biphasic solvent (water: ethyl acetate) and NaCl in the reaction medium. The intermediate result in the hydrolysis\dehydration reaction was analyzed using FTIR and the functional groups observed confirm the occurrence of 5-HMF in the intermediate reaction result

Waste to resource: Utilization of waste bagasse as an alternative adsorbent to remove heavy metals from wastewaters in sub-Saharan Africa: A review

Heavy metals pollution of both surface and groundwater sources of sub-Saharan Africa is alarmingly increased due to unplanned urban populations. Inadequate policies for water management, political commitment, and financial resources forced 65% of rural communities of sub-Saharan Africa to live in economic water stress areas. Sugarcane bagasse (SCB) shows high heavy metals (HMs) adsorption capacity (20–700 mg/g) through chemical entrapments to carbon-oxygen containing functional group and interior pore filling of porous surface. Various modifications like a physical/thermal, chemical, and composite form of bagasse show better adsorption performance for HMs removal. Kinetic and isotherm studies of HMs adsorption equilibrium data over SCB show that both Langmuir and Freundlich adsorption isotherms (cooperative adsorption) as the main adsorption mechanism. In addition, SCB shows potential bio-adsorbent properties for the selective adsorption of target HMs based on their physicochemical properties and shows good repeatability in acid environments. It is believed that information on this review will shed light on the current and future prospects of raw and modified SCB for HMs adsorption removal capacity. Sugarcane bagasse shows a remarkable selectivity for HMs adsorption removals based on their physicochemical properties and shows good potential capability for future utilizations in real wastewaters of developing countries. HIGHLIGHTS Bio-adsorbent (e.g. sugarcane bagasse) can be regenerated.; Sugarcane bagasse has high adsorptive capacity for both anion and cation heavy metals.; Cooperative adsorptive mechanism is well explained by Freundlich and Langmuir isotherms.