Load In Water Research Articles

Influence of suspended particulates on phosphorus loading exported from farm drainage during a storm event in the Everglades Agricultural Area

Purpose The purpose of this study was to evaluate the influence of suspended particulates on P loading captured during a single storm event. The Everglades Agricultural Area of Florida comprises 280,000 ha of organic soil farmland artificially drained by ditches, canals, and pumps. Phosphorus (P)-enriched suspended particulates in canals are susceptible to transport and can contribute significantly to the overall P loads in drainage water.

Polymer infiltrated ceramic network structures for resistance to fatigue fracture and wear

ObjectiveTo investigate fatigue fracture resistance and wear behavior of a polymer infiltrated ceramic network (PICN) material (ENAMIC, Vita Zahnfabrik). MethodsAnatomically shaped ENAMIC monolithic crowns were milled using a CAD/CAM system. The crowns were cemented on aged dentin-like composite abutments (Z100, 3M ESPE) with resin-based cement (Vita DUO Cement, Vita). The specimens were subjected to 2 types of fatigue and wear tests: (1) accelerated sliding-contact mouth-motion step-stress fatigue test (n=24) in water; and (2) long-term sliding-contact mouth-motion fatigue/wear test using a clinically relevant load (P=200N, n=8) in water. Failure was designated as chip-off or bulk fracture. Optical and scanning electron microscopes were used to examine the occlusal surface and subsurface damage, as well as to reveal the material’s microstructure. In addition, wear volume and depth were measured by X-ray micro-computed tomography. ResultsFor accelerated mouth-motion step-stress fatigue testing, 3 out of the 24 ENAMIC crowns fractured following cyclic loading up to 1700N. Minor occlusal damage and contact-induced cone cracks were observed in all surviving specimens, but no flexural radial cracks were seen. For long-term mouth-motion fatigue/wear testing under a 200N load in water, a small wear scar without significant cracks was observed in all 8 tested ENAMIC crowns. SignificanceMonolithic CAD/CAM ENAMIC crowns showed superior resistance to sliding-contact fatigue fracture and wear.

Reducing pathogens in combined sewer overflows using performic acid.

Combined sewer overflows contribute significantly to pathogen loads in surface water. Some chemical disinfectants such as chlorine have proved to reduce the levels of microorganisms even in complex matrices such as wastewater in combined sewer systems; however, some of them release toxic by-products into water bodies and increase costs of plant maintenance and repair. In this study, we determined if performic acid (PFA) disinfection units can be operated at decentralized treatment facilities and reduce bacteria, viruses, and protozoan parasites in combined sewer overflows (CSOs). The PFA dosing unit at the inflow of a CSO storage tank dosed a fixed flow volume into the inflowing stormwater and, thus, concentrations varied between approximately 12-24mgl-1. The results showed a reduction of most hygienically relevant bacteria with mean removal efficiencies of 1.8log10 for Aeromonas spp. and 3.1log10 for E. coli. For viruses, however, reduction was only observed for somatic coliphages with 2.7log10. In this setting, PFA does not seem to be suitable to remove e.g. protozoan parasites such as Giardia lamblia. In terms of operation, dosing the substance is uncritical in decentralized facilities, but the PFA needs too much time to react with pathogens after being dosed into the overflow of CSO storage tanks and before dilution with surface water in most facilities.

Effect of sugarcane cropping systems on herbicide losses in surface runoff

Herbicide runoff from cropping fields has been identified as a threat to the Great Barrier Reef ecosystem. A field investigation was carried out to monitor the changes in runoff water quality resulting from four different sugarcane cropping systems that included different herbicides and contrasting tillage and trash management practices. These include (i) Conventional – Tillage (beds and inter-rows) with residual herbicides used; (ii) Improved – only the beds were tilled (zonal) with reduced residual herbicides used; (iii) Aspirational – minimum tillage (one pass of a single tine ripper before planting) with trash mulch, no residual herbicides and a legume intercrop after cane establishment; and (iv) New Farming System (NFS) – minimum tillage as in Aspirational practice with a grain legume rotation and a combination of residual and knockdown herbicides.Results suggest soil and trash management had a larger effect on the herbicide losses in runoff than the physico-chemical properties of herbicides. Improved practices with 30% lower atrazine application rates than used in conventional systems produced reduced runoff volumes by 40% and atrazine loss by 62%. There were a 2-fold variation in atrazine and >10-fold variation in metribuzin loads in runoff water between reduced tillage systems differing in soil disturbance and surface residue cover from the previous rotation crops, despite the same herbicide application rates. The elevated risk of offsite losses from herbicides was illustrated by the high concentrations of diuron (14μgL−1) recorded in runoff that occurred >2.5months after herbicide application in a 1st ratoon crop. A cropping system employing less persistent non-selective herbicides and an inter-row soybean mulch resulted in no residual herbicide contamination in runoff water, but recorded 12.3% lower yield compared to Conventional practice. These findings reveal a trade-off between achieving good water quality with minimal herbicide contamination and maintaining farm profitability with good weed control.

Holocene climatic events recorded in palaeoflood slackwater deposits along the middle Yiluohe River valley, middle Yellow River basin, China

Palaeohydrological investigations were carried out in the middle reaches of the Yiluohe River, a major tributary in the lower–middle Yellow River basin. Typical palaeoflood slackwater deposits (SWDs) were identified in the Holocene pedostratigraphy on the cliffy river banks. Analytical results, including magnetic susceptibility and grain-size distribution data, indicated that these SWDs were deposited from the suspended sediment load in flood water. These SWDs are different from eolian loess, soils and aeolian sands in the riverbank profile. They recorded several episodes of extraordinary palaeoflood events. In the Longmenxia reaches of the Yihe River valley, these flood events were dated at 3100–3000a, 1800–1700a, 770–610a, and 420–340a using the optically stimulated luminescence method in combination with the pedostratigraphic correlations. In the Longhutan reaches of the Luohe River valley, the palaeoflood events were dated at 1975–1466a, i.e., from the Han to Wei dynasties (AD 25–534), during which the capital city on the river banks was flooded many times, as recorded in the literature. These extraordinary flood events are well correlated chronologically with the known Holocene climatic events that occurred in the Northern Hemisphere. Thus, the monsoonal climate was highly variable with both floods and droughts occurring frequently during these episodes. These results are important for understanding the response of river systems in eastern Asia to global changes.

Improving estimates of N and P loads in irrigation water from swine manure lagoons

The implementation of nutrient management plans for confined animal feeding operations requires recording N and P loads from land-applied manure, including nutrients applied in irrigation water from manure treatment lagoons. By regulation, lagoon irrigation water nutrient records in Mississippi must be based on at least one lagoon water nutrient analysis annually. Research in Mississippi has shown that N and P levels in lagoon water, and the N:P ratio, vary significantly through the year. Nutrient estimates based on one annual analysis do not account for this variability and may overestimate or underestimate N and P loads. The present study reports an improved method to more precisely estimate N and P loads in irrigation water from swine manure lagoons. The method is based on predictable annual cycles of N and P levels in lagoon water and employs simple curve-fitting of lagoon-specific formulas derived by analyses of historical data. Similarity of curves from analyses of Mississippi lagoons and other lagoon studies suggests that the method can be applied using the often limited nutrient data for a lagoon to more precisely estimate seasonal shifts of N and P and to improve the precision of estimates for N and P in irrigation water. Although the present study focused on swine manure lagoons in the southern US, recognition that the annual N cycle in lagoon water is temperature driven, suggests that additional research incorporating temperature into future models could extend these models to other types of waste treatment lagoons and climates.

Dual permeability modeling of tile drain management influences on hydrologic and nutrient transport characteristics in macroporous soil

Summary Tile drainage management is considered a beneficial management practice (BMP) for reducing nutrient loads in surface water. In this study, 2-dimensional dual permeability models were developed to simulate flow and transport following liquid swine manure and rhodamine WT (strongly sorbing) tracer application on macroporous clay loam soils under controlled (CD) and free drainage (FD) tile management. Dominant flow and transport characteristics were successfully replicated, including higher and more continuous tile discharge and lower peak rhodamine WT concentrations in FD tile effluent; in relation to CD, where discharge was intermittent, peak rhodamine concentrations higher, and mass exchange from macropores into the soil matrix greater. Explicit representation of preferential flow was essential, as macropores transmitted >98% of surface infiltration, tile flow, and tile solute loads for both FD and CD. Incorporating an active 3rd type lower boundary condition that facilitated groundwater interaction was imperative for simulating CD, as the higher (relative to FD) water table enhanced water and soluble nutrient movement from the soil profile into deeper groundwater. Scenario analysis revealed that in conditions where slight upwards hydraulic gradients exist beneath tiles, groundwater upwelling can influence the concentration of surface derived solutes in tile effluent under FD conditions; whereas the higher and flatter CD water table can restrict groundwater upwelling. Results show that while CD can reduce tile discharge, it can also lead to an increase in surface-application derived nutrient concentrations in tile effluent and hence surface water receptors, and it can promote NO 3 loading into groundwater. This study demonstrates dual permeability modeling as a tool for increasing the conceptual understanding of tile drainage BMPs.

Chemical and Isotopic Characters of the Water and Suspended Particulate Materials in the Yellow River and Their Geological and Environmental Implications

AbstractThe chemical and isotopic characteristics of the water and suspended particulate materials (SPM) in the Yellow River were investigated on the samples collected from 29 hydrological monitoring stations in the mainstem and several major tributaries during 2004 to 2007. The δD and δ18O values of the Yellow River water vary in large ranges from −32‰ to −91‰ and from −3.1‰ to −12.5‰, respectively. The characters of H and O isotope variations indicate that the major sources of the Yellow River water are meteoric water and snow melting water, and water cycle in the Yellow River basin is affected strongly by evaporation process and human activity. The average SPM content (9.635 g/L) of the Yellow River is the highest among the world large rivers. Compared with the Yangtze River, the Yellow River SPM has much lower clay content and significantly higher contents of clastic silicates and carbonates. In comparison to the upper crust rocks, the Yellow River SPM contains less SiO2, CaO, K2O and Na2O, but more TFe2O3, Co, Ni, Cu, Zn, Pb and Cd. The abnormal high Cd contents found in some sample may be related to local industrial activity. The REE contents and distribution pattern of the Yellow River SPM are very close to the average value of the global shale. The average δ30SiSPM in the Yellow River (–0.11‰) is slightly higher than the average value (–0.22‰) of the Yangtze River SPM. The major factors controlling the δ30Sispm of the Yellow River are the soil supply, the isotopic composition of the soil and the climate conditions. The TDS in the Yellow River are the highest among those of world large rivers. Fair correlations are observed among CI−, Na+, K+, and Mg2+ contents of the Yellow River water, indicating the effect of evaporation. The Ca2+ and Sr2+ concentrations show good correlation to the SO42– concentration rather than HCO3− concentration, reflecting its origin from evaporates. The NO3− contents are affected by farmland fertilization. The Cu, Zn and Cd contents in dissolved load of the Yellow River water are all higher than those of average world large rivers, reflecting the effect of human activity. The dissolved load in the Yellow River water generally shows a REE distribution pattern parallel to those for the Yangtze River and the Xijiang River. The δ30Si values of the dissolved silicon vary in a range from 0.4‰ to 2.9‰, averaging 1.34‰. The major processes controlling the DSi and δ30Sidiss of the Yellow River water are the weathering process of silicate rocks, growth of phytolith in plants, evaporation, dissolution of phytolith in soil, growth of fresh water diatom, adsorption and desorption of aqueous monosilicic acid on iron oxide and human activities. The average δ30SiDiss value of the Yellow River is significantly lower than that of the Nile River, Yangtze River and Siberia rivers, but higher than those of other rivers, reflecting their differences in chemical weathering and biological activity. The δ34SSO4 values of the Yellow River water range from −3.8‰ to 14.1‰, averaging 7.97‰. There is some correlation between SO42– content and δ34Sso4. The factors controlling the δ34SSO4 of the Yellow River water are the SO4 in the meteoric water, the SO4 from gypsum or anhydrite in evaporite rocks, oxidation and dissolution of sulfides in the mineral deposits, magmatic rocks and sedimentary rocks, the sulfate reduction and precipitation process and the sulfate from fertilizer. The 87Sr/86Sr ratios of all samples range from 0.71041 to 0.71237, averaging 0.71128. The variations in the 87Sr/86Sr ratio and Sr concentration of river water are primarily caused by mixing of waters of various origins with different 87Sr/86Sr ratios and Sr contents resulting from water‐rock interaction with different rock types.

Distribution of Bacteria Load in Fish Tissues, Pond Water and Sediment in Oyo State, Nigeria

Consumption of fresh fish especially is increasing on daily basis based in Nigeria; meanwhile Fish has been reported to capable of harbouring pathogenic bacteria and the level of its prevalence depending on many factors. The load of bacteria may results to diseases and cause biological and economical losses. The study investigated the total bacterial and enterobacterecea count in water, pond sediment, fish flesh, liver, kidney, intestine and gill from fish farms across large, medium, and small scale farms in the zone.The study was carried out in Oyo State, using Oyo state into agro-ecological segment by Oyo State Agricultural Development Programme (OYADEP). Farms in each zones were sub-grouped into Large, Medium and Small scales using stratified method. A total number of thirty-six (36) farms (5 Large, Medium and Small scales farms) were selected. Water (in a plastic bottles), soil, and fish (in a sterile polythene) samples were collected aseptically and examined for bacteria load.The total viable count (TVC) and total enterobacteriacea (TEB) were expressed in mean (cfu/g) and Log10CFU/g.The mean data were compared using one way analysis of variance (ANOVA) and Duncan Multiple Range Test.The results show that water samples from Ogbomosho zone had highest TVC and TEB and 5.73±0.29 Log10cfu/ml and 5.25±0.31 Log10cfu/mlrespectively. Evaluation of pond sediment shows that Ibadan/Ibarapa zone had highest TVC (5.89±0.26Log10cfu/g)and TEB and (5.53±0.25Log10cfu/g). Fish from Ogbomosho zone had highest TVC in gill (128.04±51.57cfu/g), liver (78.22±33.93cfu/g), kidney (66.07±31.01cfu/g), intestine (98.81±52.36cfu/g), skin (232.67±77.62cfu/g) and spleen (31.70±25.25cfu/g) while Saki zone had highest TVC in flesh (41.56±21.13cfu/g). TEB were highest in fish from Ogbomosho zone in gill (72.67±43.9cfu/g 5), kidney (45.04±29.14cfu/g), intestine (54.44±39.74), skin (110.41±65.41cfu/cm2) and spleen (31.70±25.25cfu/g) while TEB were highest in liver (35.82±17.81cfu/g) from fish from Ogbomosho zone and flesh from fish from Saki zone (21.19±12.16cfu/g). Fish from most of agro-ecological zone of Oyo State are contaminated with enterobacteria higher than the recommended values opining consumer health risk therefore, effort should be put in place to prevent culture system contamination throughout the value production chain

偏光板と全反射接触顕微鏡を用いた固気液三相界面の観察

PVA (Polyvinyl acetal) brushes have been widely used for a wet cleaning in semiconductor device fabrication. To better understanding the lubrication condition between a PVA brush and cleaning surfaces, we observed gas-liquid-solid interface using a total reflection microscope with polarization plates. First we investigated the real contact area of a POM (Polyoxymethylene) ball by applying a normal load in air and water. Then we observed the contact condition of a PVA brush. As a result, the observed real contact areas of the POM ball were agreed with the estimation from the Hertzian contact theory. In addition, the real contact area between a PVA brush and a glass plate in water was also able to observe. The real contact areas were increased with increase the normal force acting on the PVA brush. We concluded that the part of a PVA brush is contact with a cleaning surface.

Antimicrobial Effect of Photosensitized Rose Bengal on Bacteria and Viruses in Model Wash Water

Peroxides and chlorite-based sanitizers are commonly used for washing procedures. The efficacy of these sanitizers is significantly reduced in the presence of organic content and may result in the formation of harmful secondary products. Therefore, new food-grade sanitizers with enhanced antimicrobial efficacy are needed. In this work, we tested a visible light-activated photosensitizer, Rose Bengal (RB), for the reduction of microbial load in simulated wash water. Escherichia coli BL21 and bacteriophage T7 were selected as model bacterial and viral targets, respectively. Effects of duration of illumination, growth phase of the bacterium, and the presence of organic matter on efficacy of inactivation were evaluated. Photosensitized RB was able to achieve 6 log colony-forming units (CFU)/mL reduction in the exponential-phase bacteria in the presence of high organic content (2000 ppm LB broth) within 45 min of treatment. The results also demonstrated that the stationary-phase microbes were significantly more resistant to photoinactivation as compared to the exponential-phase microbes at both low and high organic loads (200 and 2000 ppm). The results indicate that RB dye can be internalized in bacteria and induces damage to the cell membrane upon photoactivation. Viral inactivation studies demonstrated that photoactivation of RB can achieve 5 log PFU/mL reduction in viral load in the presence of 2000 ppm LB after 30 min of treatment. Overall, these results highlight the efficacy of RB as an antimicrobial against bacteria and viruses in simulated wash water and demonstrate its potential as an alternative sanitizer for the food industry.

Floating faeces for a cleaner fish production

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 7:223-238 (2015) - DOI: https://doi.org/10.3354/aei00147 Floating faeces for a cleaner fish production Julia Unger1,2, Mark Schumann1,2, Alexander Brinker1,* 1Fisheries Research Station of Baden-Württemberg, Argenweg 50/1, 88085 Langenargen, Germany 2Limnological Institute, University of Konstanz, 78457 Konstanz, Germany *Corresponding author: alexander.brinker@lazbw.bwl.de ABSTRACT: Recent developments in European recirculating aquaculture systems suggest expanding potential for this extremely water-efficient technique. However, the technology still faces challenges due to concerns over economic efficiency and system stability - both essential in minimizing the risk of financially and environmentally expensive failures. One key factor in maintaining stable production conditions in a recirculation loop is the effective removal of solid waste, i.e. fish faeces. This study tested a novel approach for solid control and demonstrates the value-adding potential of floating faeces under commercial conditions in a semi-recirculating fish farm in Germany. A commercial control diet was compared with an experimental diet in which the addition of 2.5% cork granules led to the production of floating faeces. Physiological assays indicated no pathologic tissue alterations associated with the experimental feed, and growth, survival and feed conversion were unaffected. Average single-pass removal by a specially developed surface separator accounted for 78.3% of floating solids which accounted for 35.4% of total system solids. Total ammonia nitrogen concentrations in production water were roughly halved, from about 0.95 mg l-1 in the control to 0.47 mg l-1 using the cork diet, an improvement that in practice allowed a doubling of production on the same available water flow. This study shows that the application of floating faeces facilitates rapid and cost-effective removal of suspended solids, resulting in a considerable decrease of nutrient load in system and discharge water of the investigated farm. KEY WORDS: Fish welfare · Functional feed · Cork · Biofilter · Effluent management · Solid waste · Recirculating system · Water use efficiency Full text in pdf format PreviousNextCite this article as: Unger J, Schumann M, Brinker A (2015) Floating faeces for a cleaner fish production. Aquacult Environ Interact 7:223-238. https://doi.org/10.3354/aei00147 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 7, No. 3. Online publication date: October 21, 2015 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2015 Inter-Research.

Nitrogen, Phosphorus, and Carbon Budgets in Polyculture Ponds of Indian Major Carps and Giant Freshwater Prawn in Orissa State, India

A nutrient budget was quantified for six polyculture ponds of giant freshwater prawn (Macrobrachium rosenbergii) and Indian major carps (Catla catla, Labeo rohita, and Cirrhinus mrigala). The initial stocking size of prawn postlarva was 16.50 ± 0.54 mm with a body weight of 0.05 ± 0.001 g. Body weight of major carps was 9.0 ± 0.89 g. The duration of culture was 280 days. Feed accounted for 82% of total nitrogen (N), 93% of total phosphorus (P), and 95% of organic carbon (OC) inputs. Harvest of prawn and carps recovered 44% N, 1% P, and 19% OC. N, P, and OC accumulated in sediment were 47%, 73%, and 69%, respectively. Nutrient load in the harvest water was 0.67 ± 0.21 kg inorganic N, 0.15 ± 0.01 kg P, and 7.72 ± 0.62 kg OC per ton of Indian major carps and prawn.

Comparison between ultrafiltration and nanofiltration hollow-fiber membranes for removal of natural organic matter–a pilot study

Increasing trends of natural organic matter (NOM) in surface water in Nordic countries may cause future problems for drinking water producers. Emerging membrane technology, such as ultrafiltration (UF) and nanofiltration (NF), has the potential to produce safe drinking water of good quality from sources with high organic concentrations. In the present pilot study, surface water from three sources was treated by direct filtration on a hollow fiber ultrafilter (HFUF) and/or a hollow fiber nanofilter (HFNF). UV-absorbance (UVA) and total organic carbon (TOC) showed a high percentage of NOM removal by HFUF/coagulation, with retentions of around 75% for UVA and 55% for the TOC. NOM removal was notably greater by HFNF; with 93% in UVA retention and 88% in TOC retention. Regrettably, the water treated with HFNF retained 20–35% of the desired hardness. HFUF achieved retention comparable to traditional flocculation and sedimentation steps, while HFNF achieved even better removal of NOM. Importantly, results indicate that a membrane process with only an additional polishing step would result in decreased concentrations of NOM in the drinking water, even with higher organic loads in the raw water.

Characteristics and Driving Factors of Drainage Water in Irrigation Districts in Arid Areas

arim Basin, the largest inland river basin in China, is facing declining runoff and deteriorating water quality due to agricultural reclamation. In this study, the spatial characteristics of drainage water in Tarim Irrigation District (which is in the upstream of Tarim Basin) are analyzed using long-term drainage, irrigation and agronomic data. The driving factors behind the spatial variations in total dissolved solids (TDS) are discussed along with the feasible approaches to reducing salt loads in the drainage waters. Cluster analysis reveals three distinct TDS clusters - Type-I (7436-9651 mg/l), Type-II (5899-7640 mg/l) and Type-III (3408-4084 mg/l) clusters. The spatial variations in TDS in the study area are not significantly influenced by irrigation water source, halide dissolution and ion exchange in soils or the wide use of water-saving technology. Reclamation of new arable lands, limitations on farmland areas or discharge canal lengths and the surrounding environmental conditions (such as reservoirs or wastelands) are the main factors driving the spatial variations in TDS in the region. It is suggested to reduce salt load in drainage waters by decreasing irrigation water amount, prohibiting reclamation of new farmlands, improving drainage systems and changing flow destination of drainage waters from rivers to deserts/wastelands. In-depth analysis of spatial variations in TDS along with the causes and countermeasures could benefit the optimization of agricultural drainage water and regional water management in the study area and other arid regions.

Large mammals in Ruaha National Park, Tanzania, dig for water when water stops flowing and water bacterial load increases

As water is essential for life, animals have adaptations that increase their ability to survive during periods of water shortage. Accessing water by digging is one behavioural adaptation to water shortage used by some African mammals. Digging might also provide access to higher quality water below ground when surface water quality is poor. We investigated the digging of waterholes by wildlife in the Ruaha National Park (NP), in central Tanzania, during three dry seasons (June to November from 2011 to 2013). We monitored surface water availability and water quality at 10 sites along the Great Ruaha River (GRR) and eight non-GRR sites. We used camera-traps and direct observations to determine when and where digging to access water occurred. Elephant (Loxodonta africana), plains zebra (Equus quagga), warthog (Phacochoerus africanus) and yellow baboon (Papio cynocephalus) dug waterholes and a further four species drunk from these holes. Waterholes were dug later in the dry season along the GRR (October) than at other sites (July). The likelihood of digging and drinking from waterholes was lower along the GRR than at non-GRR sites and did not depend on the absence of surface water but increased when surface water stopped flowing. Digging of waterholes was also significantly more likely when the bacterial load in available surface water increased but was independent of salinity levels. Escherichia coli load, indicative of faecal contamination, significantly increased with total aerobic bacterial load. Our results suggest that digging is an adaptation to avoid the ingestion of poor quality surface water highly contaminated with faeces, and thereby possibly also potentially pathogenic microbes, in addition to providing access to water when surface water is absent. Our findings also highlight (1) the essential role of the GRR as the key water source for wildlife in the Ruaha NP during the dry season, and (2) that maintenance of water flow throughout the dry season is essential to prevent deterioration of water quality in the GRR.

Ultraviolet photopolymerization and performances of fast‐water absorbing sodium polyacrylate

ABSTRACTA kind of fast‐water absorbing sodium polyacrylate was prepared by UV polymerization under no crosslinker or initiator condition. Influence of factors, such as exposure time, neutralization degree, polymerization temperature, and monomer concentration on the absorption rate of the resin, were investigated. Its pH sensitivity, average absorption rate in distilled water and saline under load were also studied, respectively. The obtained resin reached to considerably high absorption rate: 4.6 g/g min and 2.6 g/g min even under 8000 Pa load in distilled water and 0.9% NaCl solution, respectively. Simultaneously, the resin displayed excellent water absorbency and water retention capacity. The impact of pH value on absorption rate reflected that the absorption rate was greatly influenced by pH. Synthesized polymer was characterized by FTIR, 1H‐NMR, and SEM. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42787.

EFFECTS OF SOURCES OF IRRIGATION WATER AND PESTICIDES ON POSTHARVEST QUALITY OF THREE VEGETABLES IN THE WA MUNICIPALITY OF THE UPPER WEST REGION OF GHANA

The objectives of the study were to document sources of irrigation water, microbial load in the water and in vegetables, pesticides used and its residue in produce and postharvest treatments applied to produce. A survey and laboratory experiments were used in the study. One hundred (100) respondents were interviewed and the data analysed using SPSS 19. Data of microbial content and pesticides residue in produce were analysed using Statistix 9. Major source of irrigation water for vegetable production was dug out well (88%). Watering cans and buckets were the common aids for irrigation (82%) adopted during the dry season vegetable farming. Cypermethrin, dichlorodiphenyl trichloroethene (DDT), Lamda and Actelic 25 EC were the most common pesticides used in controlling pests and diseases. The major postharvest treatment applied to the produce was washing of vegetables in salted water (45%). Consumption of contaminated vegetables, resulted in, stomach ache (77.5%) and diarrhea (22.5%). Laboratory analysis of water for irrigation and the vegetables produced thereof, indicated the presence of total coliforms, faecal coliforms, E. coli and Salmonella. Heptachlor, Alpha Endosulfan, Endrin, 1,1-dichloro-2, 2-bis(4-chlorophenyl) ethylene (PP-DDE), 1,1,1-dichlo-2,2-bis (4-chlorophenyl) ethane (PP-DDT) and Permethrin were pesticides residues found exceeding the International Maximum Residue Level (MRL) allowed in vegetables.

SANITATION OF PROCESS WATER FROM FRESH-CUT LETTUCE PRODUCTION BY MEANS OF UV-C

During fresh-cut production, the process water represents a major source of cross-contamination, facilitating foodborne pathogen transfer. Therefore, the efficacy of UV-C disinfection to reduce the microbiological load of lettuce wash waters was investigated. Wash water of iceberg and oak leaf lettuce was subjected to different doses of UV-C ranging from 34.8-174.2 J L-1. As shown by the inactivation kinetics of total mesophilic viable counts, UV-C was highly efficient in reducing the microbial load of both lettuce wash waters. At 174.2 J L-1, the initial viable counts were reduced by 3.2 and 2.1 log10 cfu ml-1 in iceberg and oak leaf lettuce process water, respectively. At this highest UV-C dose, members of the Enterobacteriaceae family were even reduced by 3.5 log10 cfu ml-1 in oak leaf lettuce wash water, while they were not detected in washing water of iceberg lettuce processing. Microbial loads in oak leaf lettuce wash water were higher than in that of iceberg lettuce processing, which was also reflected by a higher chemical oxygen demand (COD), higher absorption and turbidity. In the second experiment, conducted with iceberg lettuce and endive, UV-C lamps were installed in an industrial tubular washing system. Highly contaminated shredded lettuce was circulated six times in the tubes. Water and lettuce samples were analysed throughout processing. Despite high turbidities of up to 34.5±0.7 NTU, UV-C illumination reduced the viable counts in the water by 2.0 (endive) and 1.9 log10 cfu ml-1 (iceberg lettuce) after the sixth cycle compared to untreated process water. Both experiments proved UV-C treatment to be a promising option for product quality enhancement and sanitation of water during fresh-cut lettuce production, thus reducing the consumption of fresh water and microbial hazards. However, the efficacy of UV-C disinfection was shown to depend on physicochemical parameters, e.g., absorption, turbidity and COD of the water.

Assessment of spatiotemporal variations in the fluvial wash-load component in the 21st century with regard to GCM climate change scenarios

For stream water, in which a relationship exists between wash-load concentration and discharge, an estimate of fine-sediment delivery may be obtained from a traditional fluvial wash-load rating curve. Here, we demonstrate that the remaining wash-load material load can be estimated from a traditional empirical principle on a nationwide scale. The traditional technique was applied to stream water for the whole of Japan. Four typical GCMs were selected from the Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble to provide the driving fields for the following regional climate models to assess the wash-load component based on rating curves: the Model for Interdisciplinary Research on Climate (MIROC), the Meteorological Research Institute Atmospheric General Circulation Model (MRI-GCM), the Hadley Centre Global Environment Model (HadGEM) and the Geophysical Fluid Dynamics Laboratory (GFDL) climate model. The simulations consisted of an ensemble, including multiple physics configurations and different Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5), which was used to produce monthly datasets for the whole country of Japan. The impacts of future climate changes on fluvial wash load in Japanese stream water were based on the balance of changes in hydrological factors. The annual and seasonal variations of the fluvial wash load were assessed from the result of the ensemble analysis in consideration of the Greenhouse Gas (GHG) emission scenarios. The determined results for the amount of wash load increase range from approximately 20 to 110% in the 2040s, especially along part of the Pacific Ocean and the Sea of Japan regions. In the 2090s, the amount of wash load is projected to increase by more than 50% over the whole of Japan. The assessment indicates that seasonal variation is particularly important because the rainy and typhoon seasons, which include extreme events, are the dominant seasons. Because fluvial wash-load-component turbidity appears to vary exponentially, this phenomenon has an impact on the management of social capital, such as drinking water services. Prediction of the impacts of future climate change on fluvial wash-load sediment is crucial for effective environmental planning and the management of social capital to adapt to the next century. CapsuleWe demonstrate that simulations comprise an ensemble of factors, including multiple physical configurations, associated with the wash-load component for the whole of Japan.