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Understanding the spatial dynamics of soil loss (SL) and sediment yield (SY) from ungauged watersheds would have a profound importance to devise informed land resource and flood management strategies. Such information particularly substantial for rivers like Koshi, that typically causing severe land degradation and frequent devastating flood risks to large number of inhabitants in the basin. This study aimed to estimate the spatial heterogeneity of mean annual SL and SY in Triyuga river watershed (TRW) and delivers into Sapta-Koshi. The Revised Universal Soil Loss Equation (RUSLE) and Slope-based Sediment Delivery Ratio (SDR) models along with Geographic Information System (GIS) and remote sensing techniques were applied. The mean SL and SY were found to be 31 and 3.04 t/ha/year, respectively. Accordingly, an estimated 2.2 × 105 tons of sediment was delivered into the Sapta-Koshi river annually. In this watershed, nearly 62% of the area is under the category of high to very severe soil loss rate (SLR), which together accounted for 96% of the total SL in the TRW. The critical SLR was mostly distributed along the northern escarpment of the study area. Most of the sloping areas in the northwestern and some patches of the northeastern tip regions that accompany with slope class > 26.8% are particularly vulnerable to severe SL and SY in the TRW. In this regard, the RUSLE LS factor has played the significant (r = 0.88, p

Currently, vehicle-related particulate matter is the main determinant air pollution in the urban environment. This study was designed to investigate the level of fine (PM2.5) and coarse particle (PM10) concentration of roadside vehicles in Addis Ababa, the capital city of Ethiopia using artificial neural network model. To train, test and validate the model, the traffic volume, weather data and particulate matter concentrations were collected from 15 different sites in the city. The experimental results showed that the city average 24-hr PM2.5 concentration is 13%–144% and 58%–241% higher than air quality index (AQI) and world health organization (WHO) standards, respectively. The PM10 results also exceeded the AQI (54%–65%) and WHO (8%–395%) standards. The model runs using the Levenberg-Marquardt (Trainlm) and the Scaled Conjugate Gradient (Trainscg) and comparison were performed, to identify the minimum fractional error between the observed and the predicted value. The two models were determined using the correlation coefficient and other statistical parameters. The Trainscg model, the average concentration of PM2.5 and PM10 exhaust emission correlation coefficient were predicted to be (R2 = 0.775) and (R2 = 0.92), respectively. The Trainlm model has also well predicted the exhaust emission of PM2.5 (R2 = 0.943) and PM10 (R2 = 0.959). The overall results showed that a better correlation coefficient obtained in the Trainlm model, could be considered as optional methods to predict transport-related particulate matter concentration emission using traffic volume and weather data for Ethiopia cities and other countries that have similar geographical and development settings.

Currently, the depletion of natural resources and contamination of the surrounding environment demand a paradigm shift to resource recycling and reuse. In this regard, phosphorus (P) is a model nutrient that possesses the negative traits of depletion (will be exhausted in the next 100 years) and environmental degradation (causes eutrophication and climate change), and this has prompted the scientific community to search for options to solve P-related problems. To date, P recovery in the form of struvite from wastewater is one viable solution suggested by many scholars. Struvite can be recovered either in the form of NH

Metastasis includes tumor invasion and migration and underlies over 90% of cancer mortality. The metastatic effects of environmental carcinogens raised serious health concerns. However, the underlying mechanisms remained poorly studied. In the present study, an in vivo Ras

Wastewaters in textile industry are mainly characterized by higher pH, color, salt and chemical oxygen demand (COD) values, which are environmentally undesirable. Among these textile effluent characteristics, color removal is the most challenging task. In this study, the potential of Rift Valley halotolerant and thermo-alkaliphilic microbial consortia (collected from Shala hot spring located in Ethiopia) for azo dye biodegradation under anaerobic-aerobic conditions were evaluated. Optimization and microbial diversity analysis were done using Reactive Red 141. Under optimum conditions of pH (9), temperature (55 °C), salinity (0.5%), and nutrients, microbial consortia can remove98% color and 92.7 ± 7.3% COD under anaerobic and aerobic conditions, respectively. In addition, the consortia was capable of decolorizing initial dye concentrations of 100-1000 mg/L, and various dye types including Everzol Blue LX, RY 84, RR 239, RB 198 and RY 700. The 16S rRNA gene sequence results showed that Bacteroidetes (25.3%) Proteobacteria (21.0%) Chloroflexi (18.5%) Halobacterota (6.2%) dominant phyla. Based on the findings, non-color effluent adapted Rift Valley halotolerant and thermo-alkaliphilic bacterial consortia can be a potential candidate for bioremediation of textile and other industries characterized by higher salinity, temperature and pH.

Half of the world's population relies on biomass fuels for cooking and heating, which contributes to global forest depletion that leads to environmental and human health impacts. Although biomass consumption is unavoidable, using Mirt stoves save biomass fuel consumption and time for cooking. Currently, improved cooking stoves (ICS) are disseminating worldwide including sub-Saharan countries. However, studies on factors that influence the adoptions and fuel-saving performance of ICS were limited. This study was carried out to assess factors that determine the adoption and fuel use efficiency of Mirt stoves in Dilla district, Southern Ethiopia. Data were collected using questionnaires from 384 households. To test fuel use efficiencies a triplicate controlled cooking test (CCT) was made. The data gathered from questionnaires and CCT were analyzed using binary logistic regression and t-test statistical tools, respectively. The regression results revealed that marital status, household income and availability of stoves were significantly (P 0.05) difference in the length of time to bake a given amount of Injera and the amount of charcoal extracted. Our result suggested that improve cooking stoves like Mirt stove could ease the burden fuelwood collection of rural households and the efforts made to improve the adoption of Mirt stove could be successful when ICS dissemination programs consider socio-economic and market-related factors into account.

Bacterial wilt of enset caused by Xanthomonas campestris is a devastating disease in Ethiopia, where enset is domesticated and served as a staple food for about 20 million people in the country. While enset is infected by bacteria, it shows different wilting stages. However, the microbial community shifts at the different stages of enset infection and associated physicochemical parameter changes remain poorly understood. This study was aimed to visualize the proportion of enset wilt bacterium from other microbial community and its association with physicochemical parameter at different states of enset health. Soil and enset (zero, first, second and third stages) samples were collected from three districts in Gamo Highlands for physicochemical and biological (culture dependent and16S rRNA gene sequence) analysis. The results of culture dependent analysis which has been complemented by 16S rRNA gene sequence confirmed that increasing trends were observed for Xanthomonadaceae, Pseudomonadaceae, Lactobacillaceae and Flavobacteriaceae, while Bacillaceae and Enterobacteriaceae showed progressive decrease from zero to the third stage. Particularly, the 16S rRNA data showed that Xanthomonadaceae increased significantly from zero to different (2.5 × 102 times at the onset of disease and 1.0–2.0 × 104 times at the second and third) stages of enset infection. Most physicochemical results showed that a decreasing trends from zero to third stage, while few parameters are showing an increasing trend. Moisture content (R2 ≥ 0.951, P ≤ 0.049) of the soil and plant samples positively influenced Xanthomonas abundance, while this bacterium showed a strongly negative significant correlation with pH (R2 ≥ −0.962, P ≤ 0.038), temperature (R2 ≥ −0.958, P ≤ 0.042), OM (R2 ≥ −0.952, P ≤ 0.048), and TN (R2 ≥ −0.951, P ≤ 0.049). A strongly negative significant correlation (R2 ≥ −0.948, P ≤ 0.050) was also observed between Xanthomonas and nutrients (K, Mg, Ca, and Cu). Overall, this study implies that different environmental factors found a key driving force of Xanthomonas proportional increment from low abundance at zero stage to higher abundance at the last stage of enset infection suggesting that considering these factors help to design an effective enset disease management strategy, for which further studies will be needed.

This study investigated forest cover change and the driving forces behind it in Fagita Lekoma District of Ethiopia that resulted in increased forest cover, which might be uncommon outside this case study area. The LULC change analysis was made from 2003 to 2017 based on Landsat images. Socioeconomic analysis was carried out to identify the major driving forces that resulted in LULC change. A questionnaire survey, focused group discussion, key informant interviews and field observation were employed to analyze the link between LULC change and the driving forces. The 15-year period (2003–2017) image analysis revealed that the coverage of forest lands, built-up areas and grassland has increased by 256%, 100% and 96%, respectively, at the expense of cultivated lands and wetlands. The increased forest cover is due to the woodlots expansion of Acacia decurrens Willd, which are designed for sustainable livelihoods and a land revitalization strategy in the study area. Rapid population growth, an increasing demand for charcoal and subsequent market opportunities, preferred qualities of A. decurrens or black wattle to halt land degradation as well as to improve land productivity, have been identified as the major driving forces of forest cover change. Chi squared analysis revealed that: a comparative cash income from the sale of A. decurrens; a dependency on natural forests; the distance from the district administrative center; the size of the active labor force, and the area of land owned have significantly affected the cover change. The major forest cover change is due to the expansion of A. decurrens plantations that have socioeconomic and environmental implications to improve rural livelihoods and revitalize the land. Thus, the positive experiences identified in this study should be scaled-up and applied in other similar settings.

The present work provides the first attempt of using manganese dioxide loaded poly(sodium acrylate) hydrogel (MnO2@PSA) to address potential threats posed by oxytetracycline (OTC) antibiotics in aqueous environment. The MnO2@PSA was prepared via a facile approach and demonstrated enhanced removal performance even under extremely high concentrations of OTC. The outstanding performance exhibited by MnO2@PSA was attributed to synergetic effects of adsorption oxidative degradation. The synthesized composite was characterized evaluated under varying conditions. The adsorption pH was optimized at pH 5, at which the removal efficiency OTC was reached 91.46%. According to the kinetics study, the pseudo-second-order kinetic model was the best to explain the adsorption data, implying the interaction mechanisms were dominated by chemisorption. The Langmuir isotherm model was the best to explain the isotherm data, and the corresponding maximum adsorbed amount of OTC was 1150.4 mg g−1. The MnO2@PSA was highly selective for OTC adsorption and degradation under the presence of natural organic matter and common environmental metal ions. The oxidative degradation study indicated that OTC molecules were structurally degraded into 15 intermediate products via six reaction pathways. Both the theoretical models and spectroscopic methods demonstrated the removal mechanism of OTC onto MnO2@PSA was governed by ion exchange, cation-π bonding, hydrogen-bonding, and π-π electron donor-acceptor. Overall, MnO2@PSA is an excellent and environmentally sustainable material to remove OTC from water and wastewater via the combined effects of adsorption and oxidative degradation.

The increasing levels of nitrogen oxyanion pollution especially nitrate in water environments have become a critical issues of concern because of the potential risk on ecology and human health. Owing to its distinctive merits of sustainability, lesser operational and maintenance expenditure, the utilization of constructed wetland systems for the treatment of wastewater has turned out to be predominant worldwide. Its nitrogen oxyanion removal performance has received significant attention in the last two decades. This chapter presents a comprehensive outline of the application of constructed wetlands (CW) for nitrogen oxyanion removal from water and wastewater. The removal mechanisms and transformations of nitrogen are also discussed. In addition, the major factors that influence the removal performances in CWs are elucidated, especially the types of carbon sources commonly used, and how it affects the denitrification process. This chapter would be useful to engineers and researchers in the field of water and wastewater engineering.

Sulfur autotrophic denitrification (SAD) process, as an alternative to heterotrophic denitrification (HD) filter, receives growing interest in polishing the effluent from secondary sewage treatment. Although individual studies have indicated several advantages of SAD over HD, rare study has compared these two systems under identical condition and by using real secondary effluent. In this study, two small pilot scale filters (SAD and HD) were designed with identical configuration and operated parallelly by feeding the real secondary effluent from a WWTP. The results showed SAD filter can be started up without the addition of soluble electron donor, although the time (14 days) was about 3 times longer than that of HD filter. The nitrate removal rate of SAD filter at HRT of 1.4 h was measured as 0.268 ± 0.047 kg N/(m3∙d). Similar value was observed in HD filter with supplementing 90 mg/L COD. The COD concentration of effluent always kept lower than that of influent in SAD filter but not in HD filter. In addition, SAD filter could maintain a stable denitrification performance without backwash for 15 days, while decline of nitrate removal rate was observed in HD filter just 2 days after stopping the backwash. This different behavior was further confirmed as the SAD filter had a better hydraulic flow pattern. Analysis according to high-throughput 16S rRNA gene-based Illumina MiSeq sequencing clearly showed the microbial community evolution and differentiation among the samples of seed sludge, SAD and HD filters. Finally, the economic assessment was carried out, showing the operation cost of SAD filter was over 50% lower than that of HD filter.

Pyridine contamination poses a significant threat to human and environmental health. Due to the presence of nitrogen atom in the pyridine ring, the pi bond electrons are attracted toward it and make difficult for pyridine treatment with biological and chemical methods. In this study, coupling Fenton treatment with different biological process was designed to enhance pyridine biotransformation and further mineralization. After Fenton oxidation process optimized, pretreated pyridine was evaluated under three biological (anaerobic, aerobic and microaerobic) operating conditions. Under optimum Fenton oxidation, pyridine (30–75%) and TOC (5–25%) removal efficiencies were poor. Biological process alone also showed insignificant removal efficiency, particularly anaerobic (pyridine = 8.2%; TOC = 5.3%) culturing condition. However, combining Fenton pretreatment with biological process increased pyridine (93–99%) and TOC (87–93%) removals, suggesting that hydroxyl radical generated during Fenton oxidation enhanced pyridine hydroxylation and further mineralization in the biological (aerobic > microaerobic > anaerobic) process. Intermediates were analyzed with UPLC-MS and showed presence of maleic acid, pyruvic acid, glutaric dialdehyde, succinic semialdehyde and 4-formylamino-butyric acid. High-throughput sequencing analysis also indicated that Proteobacteria (35–43%) followed by Chloroflexi (10.6–24.3%) and Acidobacteria (8.0–29%) were the dominant phyla detected in the three biological treatment conditions. Co-existence of dominant genera under aerobic/microaerobic (Nitrospira > Dokdonella > Caldilinea) and anaerobic (Nitrospira > Caldilinea > Longilinea) systems most probably play significant role in biotransformation of pyridine and its intermediate products. Overall, integrating Fenton pretreatment with different biological process is a promising technology for pyridine treatment, especially the combined system enhanced anaerobic (>10 times) microbial pyridine biotransformation activity.

Hydrogen-entangled electron transfer has been verified as an important extracellular pathway of sharing reducing equivalents to regulate biofilm activities within a diversely anaerobic environment, especially in microbial electrosynthesis systems. However, with a lack of useful methods for in situ hydrogen detection in cathodic biofilms, the role of hydrogen involvement in electron transfer is still debatable. Here, a cathodic biofilm was constructed in CH(4)-produced microbial electrosynthesis reactors, in which the hydrogen evolution dynamic was analyzed to confirm the presence of hydrogen-associated electron transfer near the cathode within a micrometer scale. Fluorescent in situ hybridization images indicated that a colocalized community of archaea and bacteria developed within a 58.10-μm-thick biofilm at the cathode, suggesting that the hydrogen gradient detected by the microsensor was consumed by the collaboration of bacteria and archaea. Coupling of a microsensor and cyclic voltammetry test further provided semiquantitative results of the hydrogen-associated contribution to methane generation (around 21.20% ± 1.57% at a potential of −0.5 V to −0.69 V). This finding provides deep insight into the mechanism of electron transfer in biofilm on conductive materials. IMPORTANCE Electron transfer from an electrode to biofilm is of great interest to the fields of microbial electrochemical technology, bioremediation, and methanogenesis. It has a promising potential application to boost more value-added products or pollutant degradation. Importantly, the ability of microbes to obtain electrons from electrodes and utilize them brings new insight into direct interspecies electron transfer during methanogenesis. Previous studies verified the direct pathway of electron transfer from the electrode to a pure-culture bacterium, but it was rarely reported how the methanogenic biofilm of mixed cultures shares electrons by a hydrogen-associated or hydrogen-free pathway. In the current study, a combination method of microsensor and cyclic voltammetry successfully semiquantified the role of hydrogen in electron transfer from an electrode to methanogenic biofilm.

Available freshwater scarcity significantly affects sustainable food production for the rapidly growing population. This problem has forced people in most parts of the world to use wastewater as a viable solution. However, wastewater reuse has some deleterious effects on human and environmental health. This study was designed to investigate the health risks (HRs) of heavy metals (HMs) from vegetables irrigated with untreated and treated wastewater. The composite wastewater was collected at various sites in Arba Minch town and subjected to aerobic-anoxic treatment. Treated and untreated wastewater (UTW) was used to irrigate vegetables (lettuce, cabbage and tomato), and HM results were compared with the control (tap water) and standards. Water, soil and vegetables were investigated for various physical and chemical properties. Human health effects due to vegetable consumption were analyzed using HR- index (HRI), target hazard quotient (THQ) and hazard index (HI). The results revealed that most of the water quality indexes were significantly enhanced after aerobic-anoxic treatment, suggesting that wastewater collected from different sites was suitable for biodegradation. Soil physicochemical analyses also showed that pH, cation exchange capacity, organic carbon and organic matter were higher for UTW irrigated soil. Heavy metal concentrations were relatively greater in soils than water used for irrigation purposes and vegetables. The HM concentration in vegetables was higher for UTW than for treated and tap water irrigated vegetables. In vegetables, the order of HM content was Fe > Mn > Zn > Pb > Cu > Cd. Tomato followed by cabbage and lettuce accumulated significant amount of HMs (Fe > Mn > Zn > Pb > Cu > Cd) in their different organs (fruit/leaf>root>stem). The individual and combined health indexes (HRI, THQ and HI) showed that Pb and Cd have values greater than unity for wastewater irrigated vegetables, which could result in non-carcinogenic disease for short/lifetime exposure in adults and children. Overall, consumption of vegetables can be safer when grown with treated effluent than with UTW.

Phosphorus recovery from urine is a sustainable approach. However, the challenge of this process is the accessibility of economically feasible magnesium sources. This study aimed to investigate the potential of low-cost Rift Valley Lake magnesium (RVL-Mg) source for phosphorus recovery from urine, where data is deficient in the source area. The effect of various operational conditions such as storage, Mg:P ratio (0.8-2.0), pH (5.5-10.5), mixing speed (30-180 rpm), urease enzyme addition (50-700 μL), urine dilution (0.11-9.0) and Ca:Mg ratio (0.3-2.5) was investigated. Under optimum operating conditions (M:P = 1.6, pH = 9, urease enzyme = 500 μL, mixing speed = 120 rpm, 60 min precipitation), the phosphorus removal efficiencies were96% for actual and98% for synthetic urine. During storage, spontaneous phosphorus losses were observed from synthetic (24.0%) and actual (32.0%) hydrolyzed urine due to precipitation with calcium and magnesium. The phosphorus recovery efficiency was reduced at higher (0.11:1) and lower (9:1) urine to RVL-Mg dilution, which is related to lower supersaturation of phosphorus and magnesium ions, respectively. Addition of calcium did not affect phosphorus removal efficiency, but the effect was significant on crystal product. With low (1.0) Ca:Mg ratio, the crystal chemical analysis showed that the product has to be pure struvite (99%), which was further identified by scanning electron microscope and X-ray diffraction to be quality struvite that might be used for agricultural purpose. Overall, low-cost magnesium ion collected from Rift Valley Lake can be a potentially candidate for sustainable phosphorus recovery from urine and any other phosphorus containing waste stream.

Background: Gastrointestinal helminths (GIH) are widespread in developing countries including Ethiopia. The prevalence and distribution of GIH infection in Ethiopia varies from place to place due to different exposing risk factors. This study aimed to identify the prevalence and associated factors of GIH infection among primary school children in Dembi district, southwest Ethiopia, where data for helminths infections are previously unpublished. Methods: A cross-sectional study involving 291 school children in Dembi district were included. Fresh stool samples were collected from each student and examined by direct wet mount using both normal saline and Lugol's iodine preparation and concentration techniques using salt and formol-ether solutions. Questioners and observation were also used to identify socio-demographic and associated risk factors. Data were analyzed using SPSS 20.0 statistical software. p-value Results: Six parasite species of gastrointestinal helminth with an overall prevalence of 30.9% were identified. The predominant parasites were found soil transmitted helminth (STH) type including Ascaris lumbricoides (43.3%), hookworm (26.7%), Ttrichuris trichiura (8.9%) and Strongliodes stercoralis (3.3%). Teania species (6.7%) and Hymanolepis nana (3.3%) were also the gastrointestinal parasites detected from the stool samples. The highest prevalence of GIH infection has been observed in the age of 5 8 years children (36.7%) followed by 9 12 (33.3%) and ≥13 (30.0%) years. Sex, age, source of water supply and latrine usage has a significant association with GIH infection. Male (37.9%) students were two times more likely to have parasite infection (COR= 2.0, 95% CI= 1.17 3.22, p=0.011) than female (24%) students. Comparing age groups, 5 8 years were more likely to have higher parasite infection (COR=1.23, 95% CI=0.233 0.797, p=0.007) than older age groups ( 13 years). Those students used stream as a source of water supply and latrine sometimes were also 1.4 (p=001) and 2.7 (p=0.001) times more likely to have helminthic infection than students used pipe water and latrine, respectively. Conclusions: The results of this study showed that GIH infection are important public health problem among primary school children in Dembi district which needs an integrated health control program including periodic de-worming, improving sanitation and safe water provision.

Considering the saline-alkaline nature of textile wastewater and treatment requirements, microbial samples were collected from Ethiopian Rift Valley Soda Lakes. A large number of bacteria (121) were isolated from dye-uncontaminated Lakes Chitu (81.0%), Abijata (15.7%) and Arenguadie (3.3%), of which 95 isolates (78.5%) were found dye decolorizer. Many dye decolorizer from Lake Chitu positively correlated with higher pH (10.3 ± 0.1), salinity (64.6 ± 2.0%), conductivity (6.1 ± 0.3 mS cm − 1 ) and Na+ (18.4 ± 0.6 g L − 1 ) values observed than Abijata and Arenguadie Lakes. Through subsequent screening mechanism, strain A55 was selected to investigate the effect of nutrient (carbon and nitrogen), dissolved oxygen and dye concentration using Reactive Red 184 (RR 184). Based on morphological, biochemical and 16S rRNA gene sequence analysis, the strain was identified as Halomonas sp. Decolorization efficiencies were significantly enhanced with carbon (≥98%) and organic nitrogen (∼100%) than non-carbon/nitrogen (both

The need for an effective and efficient removal method for the combined pollution of antibiotics and heavy metals has attracted increasing attention. In this study, a novel manganese ferrite-loaded swine manure hydrochar was utilized to deal with chlortetracycline and lead in water. The SMHC was produced via the hydrothermal carbonization method and then modified with manganese ferrite (MnFe2O4) nanoparticles using the coprecipitation method. The hybrid adsorbent (MnFe2O4-SMHC) exhibited high specific surface area, abundant functional groups, and excellent magnetic properties. The CTC adsorption data were fitted to both the Freundlich and Langmuir isotherm models, while that of Cd(II) was better fitted to the Langmuir isotherm model. The maximum removal capacities corresponding to CTC and Cd(II) adsorptions were 752.96 and 62. 16 mg g−1, respectively. The removal of CTC was slightly promoted in the presence of low concentrations of Cd(II), while the presence of CTC showed antagonistic effects on the uptake of Cd(II). The spent MnFe2O4-SMHC was collected after adsorption using an external magnetic field for subsequent regeneration and reuse, and the result showed its excellent recyclability. In summary, MnFe2O4-SMHC exhibited excellent adsorption performance for CTC and Cd(II) removal in single and binary conditions, suggesting its potential application in water and wastewater remediation.

The environmental spread of antibiotic resistance genes (ARGs) from the direct application of traditional biological treatment systems for antibiotics in water is a potential public health threat. UV photolysis has been proved to be an efficient pretreatment method for antibacterial activity elimination, but the fate of antibiotic resistome in subsequent bioreactors fed with pretreated florfenicol (FLO) in synthetic wastewater is still unknown. Antibacterial activity in synthetic wastewater was effectively eliminated by UV irradiation pretreatment, and the diversity and abundance of detected ARGs in both aerobic and anaerobic bioreactors were significantly lower than those without pretreatment. Meanwhile, UV irradiation pretreatment shaped the structure and composition of sludge microbial communities in the subsequent bioreactors closer to those of the FLO-free groups. The relative abundances of Pseudomonas and Escherichia-Shigella working as the potential hosts of ARGs were significantly reduced in aerobic and anaerobic bioreactors, respectively. The significantly positive correlation between floR and intI1 and the decrease of intI1 abundance in UV photolytic pretreatment groups indicated that the horizontal transfer of floR was decreased. The study provides new insights into the effect of preferential UV photolysis as a pretreatment method on the source control of antibiotic resistome in subsequent biological treatment process.

In this study, hydrous manganese dioxide (HMO) modified poly(sodium acrylate) (PSA) hydrogel was produced for the first time to remove tetracycline(TC) and lead(Pb(II)) from water. The as-prepared composite was characterized using various techniques, such as SEM-EDS, FTIR, XRD, BET, and XPS, to elucidate the successful loading of HMO and analyze subsequent sorption mechanisms. Different influencing parameters such as adsorbent dose, initial concentration of adsorbates, reaction time, solution pH, and temperature were also investigated. The adsorption kinetic studies of both TC and Pb(II) removal indicated that equilibrium was achieved within 12 h, with respective removal rates of 91.9 and 99.5%, and the corresponding adsorption data were fitted to the second-order kinetics model. According to the adsorption isotherm studies, the sorption data of TC best fitted to the Langmuir isotherm model while the adsorption data of Pb(II) were explained by the Freundlich isotherm model. The maximum adsorption capacities of both TC and Pb(II) were found to be 475.8 and 288.7 mg/g, respectively, demonstrating excellent performances of the adsorbent. The uptake capacity of PSA-HMO was significantly influenced by the level of solution pH, in which optimum adsorption amount was realized at pH 4.0 in the TC and Pb(II) systems, respectively. Thermodynamic studies showed the process of TC and Pb(II) adsorptions were endothermic and spontaneous. Overall this study elucidated that PSA-HMO composite can be a promising candidate for antibiotics and heavy metal removal in water treatment applications.

Graphical abstract, Highlights • Bacillus sp. strain CH12 is a potential candidate for dye removal. • Strain CH12 needs alkaline pH (9–10) to bring complete dye removal efficiency. • Organic carbon and nitrogen supplements enhance dye decolorization efficiency. • Sodium nitrite and sodium nitrate lead to lower decolorization efficiency. • Under oxygen tension conditions, dye can be used as a final electron accepter., Textile azo dye decolorizing bacteria were isolated from alkaline Lakes Abaya and Chamo using Reactive Red 239 (RR239) dye. Through subsequent screening process, strain CH12 was selected to investigate the effects of nutrient supplement, DO, pH, temperature, dye concentration and types on decolorization. Based on 16S rRNA gene sequence analysis, strain CH12 was identified as Bacillus sp. Decolorization efficiencies were significantly enhanced with carbon (≥98%) and organic nitrogen (∼100%) supplements. Complete decolorization was also observed under anoxic and anaerobic conditions, and at the temperature of 30 °C and the pH of 10. However, the azo dye decolorization efficiency of strain CH12 was significantly reduced when NaNO3 (1–8%) was supplemented or under aerobic culturing condition (≤6%), indicating that RR239 was less preferred electron acceptor. Overall, strain CH12 can be a promising candidate for decolorization applications due to its potential to effectively decolorize higher RR239 concentrations (50−250 mg/L) and six additional dyes.

The agricultural sector requires a large volume of water (∼70 % of global water), which makes this sector difficult to produce enough food for the rapidly growing population demand with the existing scarce available freshwater source. As a viable alternative water source, urban wastewater reuse is a potential candidate. However, wastewater reuse and disposal before treatment pose a significant threat to human health and ecological systems. This study was aimed to treat urban wastewater using aerobic-anoxic system and then effluent evaluated to grow different vegetables. Wastewater samples collected (Arba Minch town) at nine sites during different seasons were used to characterized water quality (physicochemical and biological) parameters and feed aerobic-anoxic reactors. Health risk as a result of vegetable ingestion was investigated using HRI, THQ, and HI. Statistically significant (p 96, 92, 88, and 58 %, respectively. The order of heavy metals concentration in raw wastewater was Fe > Pb > Zn > Mn > Cu > Cd, which is lower than corresponding heavy metals in vegetables having the order Fe > Mn > Zn > Pb > Cu > Cd. The phytotoxicity effect was significantly higher for cabbage followed by lettuce and tomato. The HRI, THQ, and HI values for Cd and Pb >1.0 (exceeded WHO and FAO limits) for vegetables irrigated with wastewater, which could result in health risk in adults and children. Overall, results confirmed that wastewater after aerobic-anoxic treatment is a sustainable approach to maintain safe environmental and human health.

Biochar was utilized to intensify constructed wetland (CW) for further organic and nitrogen removal from secondary wastewater. Four sets of non-aerated biochar amended vertical flow CW (VFCW) were developed to investigate the synergistic effects of biochar and microbes on pollutant removal. Results showed that the average COD and nitrogen removal efficiencies of VFCW1 (with 1% w/w biochar with microbe and plants) achieved 89.1 ± 5.6% and 90.2 ± 3.1% respectively, and their corresponding removal rates of 10.2 ± 0.8 mg-COD/(m3.d) and 3.57 ± 0.3 mg-TN/(m3.d) which were 35 and 52.3% higher than control. The biochar’s dissolved organic carbon release in VFCWs indicated that water and acidic media portray the optimum conditions for nitrogen removal. The 16S RNA gene sequencing analysis indicated that in the biochar-amended VFCWs, bacterial phylum Proteobacteria (24.13–51.95%) followed by Chloroflexi (5.64–25.01%), Planctomycetes (8.48–14.43%), Acidobacteria (2.29–11.65%) were abundantly enhanced. Conclusively, incorporating biochar in non-aerated VFCWs is an efficient technique for enhancing nitrogen removal from secondary effluent.

Tetracyclines are extensively used to treat human and animal infectious diseases due to its effective antimicrobial activities. About 70-90% of its parent materials are released into the environment through urine and feces, implying they are the most frequently detected antibiotics in the environment with high ecological risks. Adsorption and photocatalysis have been promising techniques for the removal of tetracyclines due to effectiveness and efficiency. Graphene-based materials provide promising platforms for adsorptive and photocatalytic removal of tetracyclines from aqueous environment owning to distinctive remarkable physicochemical, optical, and electrical characteristics. Herein, we intensively reviewed the available literatures in order to provide comprehensive insight about the applications and mechanisms of graphene-based materials for removal of tetracyclines via adsorption and phototocatalysis. The synthesis methods of graphene-based materials, the tetracycline adsorption and photocatalytic-degradation conditions, and removal mechanisms have been extensively discussed. Finally concluding remarks and future perspectives have been deduced and recommended to stimulate further researches in the subject. The review study can be used as theoretical guideline for further researchers to improve the current approaches of material synthesis and application towards tetracyclines removal.

Carbon coated stainless-steel (SS) electrode has been suggested to be a powerful composite electrode with high conductivity, excellent biocompatibility and good mechanical strength, which is promising for scaling up the bioelectrochemical systems (BESs). However, the already reported carbon coating methods were independent on the production of SS material. Additional steps and investment of equipment for carbon coating are costly, and the industrialization of these carbon coating processes remains challenging. In this study, we report an industrializable carbon coating approach that was embedded into the production line of the SS wire, which was realized through a wire-drawing process with graphite emulsion as the lubricant and carbon source. We found the slide of SS wire through the dies was essential for the graphite coating in terms of loading amount and stability. When the graphite coated SS wire was prepared as the anode and operated in a BESs, the current density reached 1.761 ± 0.231 mA cm−2, which was 20 times higher than that without graphite coating. Biomass analysis was then conducted, confirming the superior bioelectrochemical performance was attributed to the improvement of biocompatibility by the graphite coating layer. Furthermore, graphite coating by the wire-drawing process was systematically compared with the existing methods, which showed a comparable or even better bioelectrochemical performance but with extremely low cost (0.036 $·m−2) and seconds level of the time consumption. Overall, this study offers a cost-effective and industrializable approach to preparing graphite coated SS electrode, which may open up great opportunities to promote the development of BESs at large scale.

The aim of the present study was to evaluate macular vascular density (MVD) variation after uneventful cataract surgery using optical coherence tomography angiography (OCTA) in patients with high myopia. Patients with cataracts scheduled for cataract surgery were divided into a high-myopia group [spherical equivalent (SE)≤-6.0 diopter (D) and axial length (AL)≥25 mm] and a low-myopia group (SE>-6.0 D and AL

This study was designed to investigate the antibacterial activity of selected medicinal plants used by the Genta Meyche community in Southern Ethiopia. Ethnomedicinal data was collected from 25 herbalists through semi-structured interviews and observations. Based on the highest use value (UV), plants were selected to be tested on pathogenic bacteria. A total of 26 ethnomedicinal plant species belonging to 17 families were collected and identified. The extraction of active compounds from the selected plants was carried out using five solvents. Roots (30.8 %) and leaves (26.9 %) were the plant parts most frequently used for the treatment of gastrointestinal disorders (GIDs). Herbalists mostly prepared medicinal plants as juice (57.7 %) and administered the juice through oral routes (92.3 %). Solanum incanum L. (UV = 0.44), Harrisonia abyssinica Oliv. (UV = 0.36), Hydnora abyssinia A.Br. (UV = 0.36) and Leucas aspera (Willd.) Link. (UV = 0.32) were found to be the most frequently used medicinal plants in the study area. These plants showed a promising broad spectrum of activity against Gram-positive and Gram-negative test bacteria with growth inhibition zone and minimum inhibition concentration (MIC) values ranging from 7.40 ± 0.60 - 16.81 ± 2.03 mm and 156 - 2500 μg/mL, respectively. Among solvents, ethanol and ethyl acetate extracts showed significantly greater antibacterial activity than aqueous, acetone and chloroform extracts. Steroids, tannins, saponin, flavonoids, alkaloids and terpenoids were identified as bioactive compounds in most of the tested plants. Unused parts of Solanum incanum L. and Harrisonia abyssinica Oliv. were investigated and results exhibited potential candidacy with inhibition zones of 7.1 - 13.7 and 10.2 - 15.3 mm, respectively. Overall, the results of this study provide evidence for the treatment of GIDs by using traditional medicinal plants used by the Genta Meyche community to act against pathogenic bacteria.

Polycyclic aromatic hydrocarbons (PAHs) are regarded as priority pollutants owing to their toxic, mutagenic and carcinogenic characteristics. Perylene is a kind of 5-ring PAH with biological toxicity, and classified as a class III carcinogen by the World Health Organization (WHO). Nowadays, some of its derivatives are often used as industrial pigments. Hence, urgent attention is highly needed to develop new and improved techniques for PAHs and their derivatives removal from the environment. In this study, Fenton oxidation process was hybridized with the biological (anaerobic and aerobic) treatments for the removal of perylene pigment from wastewater. The experiments were carried out by setting Fenton treatment system before and between the biological treatments. The biological results showed that COD removal efficiency reached 60% during 24 h HRT with an effluent COD concentration of 1567.78 mg/L. After the HRT increased to 48 h, the COD removal efficiency was slightly increased (67.9%). However, after combining Fenton treatment with biological treatment (Anaerobic-Fenton-Aerobic), the results revealed over 85% COD removal efficiency and the effluent concentration less than 600 mg/L which was selected as the better treatment configuration for the biological and chemical combined system. The microbial community analysis of activated sludge was carried out with high-throughput Illumina sequencing platform and results showed that Pseudomonas, Citrobacter and Methylocapsa were found to be the dominant genera detected in aerobic and anaerobic reactors. These dominant bacteria depicted that the community composition of the reactors for treating perylene pigments wastewater were similar to that of the soil contaminated by PAHs and the activated sludge from treating PAHs wastewater. Economic analysis results revealed that the reagent cost was relatively cheap, amounting to 10.64 yuan per kilogram COD. This study vividly demonstrated that combining Fenton treatment with biological treatment was efficient and cost-effective.

Bietti crystalline dystrophy (BCD) is a rare autosomal recessive inherited disorder characterized by crystals in retinal pigment epithelium. The purpose of this study was to identify the genetic defect in Chinese families with BCD and analyze their clinical features. The clinical examination and genetic studies were performed in three BCD families at Tongji University Hospital. Eye examination included fundus fluorescein angiography, slit lamp, fundus photograph, optical coheres tomography and visual acuity examination has been carried out. Blood samples were collected from three pro-bands and their family members. Genomic DNA extracted from whole blood used for polymerase chain reaction (PCR) to identify genetic defect. Fundus examination revealed that the presence of tiny yellowish-sparkling crystals at the posterior pole of the fundus and atrophy of the retinal pigment epithelium in some patients. The PCR results also showed that three different mutations in the three families including Family C with compound heterozygous mutations of deletion c.802-8_810del17bpinsGT and insertion c.1062dupA, Family B with compound heterozygous mutations of a splicing mutation c.1091-2A>G and deletion mutation c.802-8_810del17bpinsGC and Family A with homozygous deletion mutation c.802-8_810del17bpinsGC. In this study, the PCR result also identified CYP4V2 as the disease causative gene in three Chinese families with BCD. Overall, these findings broaden the spectrum of CYP4V2 mutations that cause BCD and characterize phenotypic features of the disease in Chinese families.

Effect of intermittent aeration cycle (IAC=15/45-60/60min) on nutrient removal and microbial community structure was investigated using a novel fluidized bed reactor-membrane bioreactor (FBR-MBR) combo system. FBR alone was found more efficient for removing PO4-P (>85%) than NH4-N (98%). Efficient nitrification, stable mixed liquor suspended solid and reduced transmembrane pressure was also achieved. Quantitative real-time polymerase chain reaction results of total bacteria 16S rRNA gene copies per mL of mixed-liquor varied from (2.48±0.42)×109 initial to (2.74±0.10)×108, (6.27±0.16)×109 and (9.17±1.78)×109 for 15/45, 45/15 and 60/60min of IACs, respectively. The results of clone library analysis revealed that Proteobacteria (59%), Firmicutes (12%) and Bacteroidetes (11%) were the dominant bacterial group in all samples. Overall, the combo system performs optimum nutrient removal and host stable microbial communities at 45/15min of IAC. © 2014 Elsevier Ltd.

A FBR-MBR combo system was designed as a novel approach for simultaneous phosphorus and nitrogen removal from sewage. The combo system was evaluated more than 7 months under variable pH (7.5-9.5), hydraulic retention times (HRT=2-10h), intermittent aeration cycles (IAC) (on/off=60/60-15/45 min) and sludge retention times (SRT=10-60 d). Prior recovery of phosphorus as struvite in the FBR enhanced nitrogen and COD removal efficiency in MBR. Under optimum operating conditions (pH=9, HRT=6h and IAC=45/15 min), PO4(3-)-P, NH4(+)-N and COD removal efficiencies were 92.6 ± 4.2, 98.7 ± 1.2 and 99.3 ± 0.5%, respectively. Stable mixed liquor suspended solid concentration (3.0-5.0 g/L); enhanced nitrification-denitrification activity (78-92%) and reduced transmembrane pressure were also achieved. Compared to soluble microbial products, extracellular polymeric substances (EPS) showed strong correlation with fast membrane fouling. Among EPS components, carbohydrate rather than protein was associated with membrane fouling. Except HRT, all parameters considered (pH, IAC, SRT) showed a significant effect on removal efficiency.

The feasibility of struvite recovery at low (12.5 mg/L) and high (120 mg/L) phosphorus concentrations was studied by constructing a novel fluidized bed reactor with cones (FBRwc) and without cones (FBRwoc). The crystallization process was continuously operated for 133 days under different hydraulic retention times (HRT = 1–10 hr), pH (7.5–10), and molar ratios of Mg/P (0.75–1.75), N/P (1–10) and Ca/Mg (0–2). The optimum operating conditions of HRT, pH, Mg/P and N/P molar ratios were found to be 2 hr, 9, 1.25, and 7.5, respectively. Under these optimum conditions, the phosphorus precipitation efficiencies of FBRwc were 93% for low and 98% for high phosphorus influent; however, the efficiencies were 78% and 81% for FBRwoc, respectively. Due to crystal losses at each junction (17%–31%), the crystal recovery efficiency of FBRwoc was relatively low (47%–65%) for both influent concentrations. However, the losses were minimal in FBRwc, which showed 75% and 92% crystal recovery for low and high phosphorus concentrations, respectively. At low calcium concentration, crystal chemical analysis showed the product to be pure struvite (> 99%). The scanning electron microscope and X-ray diffraction results further confirmed that the crystal recovered from FBRwc contained pure struvite, which could be considered a high quality fertilizer. Except HRT, all parameters (pH, Mg/P, N/P and Ca/Mg) were found to be influencing factors for FBRwc performance. Overall, inserting cones in each part of the reactor played a significant role in enhancing struvite recovery from a wide range of phosphorus-containing wastewater.