Adjoining Water Research Articles

Impact of slaughterhouse waste on adjoining water quality

Impact of slaughterhouse waste on adjoining water quality

Physicochemical attributes and bacteriome diversity of Lake Tunari, Taraba State, Nigeria

Physicochemical parameters of aquatic habitats can play an influential part in shaping the microbial communities of water bodies. In this study, water samples from Lake Tunari were analysed for its microbiome and physicochemical attributes, using spectrophotometric and culture-dependent methodologies respectively. The temperature of the lake ranged from 28.00 – 29.00 (°C), while the pH ranged from 6.50 – 7.20. Heavy metals such as Manganese (0.48 ppm), Lead (0.14 ppm) and Selenium (0.10 ppm) showed significantly high values in selected parts of the lake, surpassing limits set by the World Health Organisation. Microbiome analysis revealed the largest phylum across sample sites as Proteobacteria, Firmicutes, and Planctomycetota with peak relative abundance values of 64.13%, 45.29% and 16.11% respectively. Bacterial genera such as Exiguobacterium, Methylocystis and Rhodoferax were detected from designated sites. The presence of these genera capable of tolerating, utilizing or degrading metal ions in water samples of the Lake might be indicative of chemical and metal trickles into the water body. In addition, relatively new and understudied bacterial phyla such as Gemmatimonadota, as well as unknown bacterial clades were identified from water samples of the lake. This study has revealed that Lake Tunari is not impervious to pollution, caused by either anthropogenic activities or from adjoining water channels. Environmental health awareness programs can be introduced to enlighten the populace, while scheduled microbial and physicochemical surveillance can be adopted, to control microbial contamination and curtail toxic material inflow into the Lake.

Nafion: New and Old Insights into Structure and Function.

The work reports a number of results on the dynamics of swelling and inferred nanostructure of the ion-exchange polymer membrane Nafion in different aqueous solutions. The techniques used were photoluminescent and Fourier transform IR (FTIR) spectroscopy. The centers of photoluminescence were identified as the sulfonic groups localized at the ends of the perfluorovinyl ether (Teflon) groups that form the backbone of Nafion. Changes in deuterium content of water induced unexpected results revealed in the process of polymer swelling. In these experiments, deionized (DI) water (deuterium content 157 ppm) and deuterium depleted water (DDW) with deuterium content 3 PPM, were investigated. The strong hydration of sulfonic groups involves a competition between ortho- and para-magnetic forms of a water molecule. Deuterium, as it seems, adsorbs competitively on the sulfonic groups and thus can change the geometry of the sulfate bonds. With photoluminescent spectroscopy experiments, this is reflected in the unwinding of the polymer fibers into the bulk of the adjoining water on swelling. The unwound fibers do not tear off from the polymer substrate. They form a vastly extended "brush" type structure normal to the membrane surface. This may have implications for specificity of ion transport in biology, where the ubiquitous glycocalyx of cells and tissues invariably involves highly sulfated polymers such asheparan and chondroitin sulfate.

Flushing or mixing? Stable water isotopes reveal differences in arctic forest and peatland soil water seasonality

AbstractUnderstanding the relative importance of different water sources that replenish soil water storage is necessary to assess the vulnerability of sub‐arctic areas to changes in climate and altered rain and snow conditions, reflected in the timing and magnitude of water infiltration. We examine spatiotemporal variability and seasonal origin of soil water at the soil‐vegetation interface in Pallas catchment, located in northern Finland. The field study was conducted from May 2019 to June 2020 over two snowmelt seasons and one summer growing season. We sampled soil cores up to a 1‐m depth and stem water of dominant tree species at four sites located in forests and forested peatlands for stable water isotopes. Seasonal rainfall variation and late snowmelt events were well identifiable in the well‐drained soils of forested areas, while this input signal is heavily attenuated in wetter, forested peatland areas. Spatiotemporal variability of soil water in two forest sites was similar, whereas soil water storage in peatland sites was controlled by the extent of hydrologic connectivity to the adjoining water pools. A mixture of both summer and winter precipitation was present in peatlands during the entire study period, while forest mineral soils showed an ephemeral response to water input and got nearly fully flushed twice during the hydrological year. Meltwater signal in forest soils was dominant after snowmelt and in early spring but became displaced by isotopically enriched rainfall during the summer. Seasonal evolution of soil water pools was not reflected in tree stem dynamics but offset between soil and stem water isotopic signals was less pronounced in forested peatlands. This field data set uncovered seasonal changes of soil water isotopic signal at high depth‐resolution, quantifying the importance of snowmelt water in replenishing and sustaining soil water storage in sub‐arctic conditions.

A basin-scale inventory and hydrodynamics of floodplain wetlands based on time-series of remote sensing data

ABSTRACT The world is rapidly losing its wetlands. To contain the loss, the first and foremost requirement is to prepare an inventory of wetlands based on historical datasets. Individual wetlands in a catchment system are not standalone entitites, and together, they control the hydrological processes of the catchment. Therefore, it is essential to map the wetlands at the catchment scale to understand their relationship with the adjoining water bodies. This will further help to develop sustainable strategies for their revival and management. In the present work, we have formulated a simple yet robust method to (a) map the wetlands and (b) document surface dynamics of wetlands by applying pixel-scale binary logic (wet/not-wet) to the time-series Landsat dataset. We have applied this method to a large basin in the Ganga Plains and mapped a total of 3226 wetlands in the basin. The method can also be applied to map wetlands at a pixel scale to a basin scale.

Assessment of biannual seasonal variations in hydrochemistry of Kerwa reservoir located in hard rock formations of Central India

An investigation on the Kerwa reservoir water located in central parts of India (Bhopal, Madhya Pradesh) has been carried out to assess the hydrochemical variations in different seasons and possible influencing factors. Temporal chemical variations in reservoir water were evaluated for all the three seasons by analyzing two hundred forty surface water samples from ten different sites along the reservoir periphery covering inlet and outlet points. The analytical results indicate that Kerwa reservoir water is mildly alkaline, and the order of dominance for ions was found to be Ca2+ > Mg2+ > Na+ > K+ and HCO3− > Cl− > SO42−. The major chemical facies present are Ca-Mg-HCO3, Ca-Mg-Na-HCO3-Cl, Ca-Mg-HCO3-Cl, and Ca-Mg-Cl-HCO3. Piper and Chadha plots infer that seasonality exert a strong control on the water chemistry. Rainwater dominate the reservoir water chemistry during monsoon, evaporation dominates during summer, while multiple geochemical reactions control the reservoir water chemistry during winter. The extent of ion exchange was evaluated by chloro-alkaline indices as well as (Ca2+ + Mg2+)/(Na+ + K+) versus Na+-Cl− plot. Contribution of carbonate and silicate minerals was evaluated using characteristic ionic ratios and scatter plots. It is found that weathering of silicate rocks lead to higher Ca2+ and Mg2+ in the reservoir water, while evaporite dissolution and to a some extent ion exchange and base flows are found to control the Na+ and K+ concentrations. With the growing scenario of contamination in adjoining water bodies, the study on water quality and associated geochemical processes becomes necessary for Kerwa reservoir, which can form a potential freshwater reserve in this region for future generations.

Structure and Dynamics of Mollusk Communities of Small Oxbow Lakes and the Determining Factors (the Khoper River Valley, Penza Oblast)

The structure and dynamics of mollusk communities, as well as environmental factors influencing them, were analyzed in small oxbow lakes of the forest-steppe zone (a case of the Khoper river valley, Penza region, Russian Federation). 19 species of mollusks were found in the studied water bodies. The oxbow lakes were characterized by relatively low alpha-diversity (number of species 4 ± 2) and relatively high beta-diversity (Jacquard index 0.26 ± 0.18), which is typical for floodplain ecosystems. Lake communities were dominated by Planorbis planorbis (40%), Lymnaea stagnalis (15%), Anisus spirorbis (14%), Lymnaea saridalensis (9%), Anisus vortex (8%). The results of our analysis showed that the group of factors that determined the type of water body (stability, light intensity, water temperature, oxygen concentrations) had the greatest impact on the structure of malacocenoses. The seasonal dynamics of mollusk communities was determined by the number of adjoining water bodies, water temperature, and dissolved oxygen concentrations. The number of adjoining oxbows was the major factor influencing mollusk species diversity, as well as the total number and biomass of mollusks. Oxbow isolation was favorable for mollusk communities. The factors influencing the highest number of mollusks species (seven) were the light intensity and the presence of fish. Other significant factors were the stability of lakes (shown for five species of mollusks), the number of adjoining oxbows and water transparency (four species). Aquatic vegetation positively correlated with the abundance of only one species—Anisus vortex. Our data suggest that the presence of fish could influence the abundance of Lymnaea saridalensis. The mollusks, in their turn, apparently, had a positive effect on the abundance of leeches in water bodies. Mollusk species most sensitive to the external factors were Lymnaea stagnalis, Lymnaea saridalensis, Aplexa turrita, Anisus spirorbis and Anisus leucostoma, most tolerant were Bathyomphalus crassus, Anisus vortex, Planorbis planorbis and Planorbarius corneus.

Distribution and Interannual Changes of the Zooplankton of the Durgun Water Basin and Adjoining Water Objects (the Western Mongolia)

The article describes quantitative and structural characteristics of zooplankton of polytypic sites of a water system including a lake, canal, and a water reservoir. It is shown that in the littoral zone of lakes and water reservoirs, the number of species and communities is higher, and biomass, lower. However, in the littoral zone of shallow lake zooplankton in number, took priority due to Rotifera, in the deep part of the water body – Rotifera and Cladocera; in the center of the lake zooplankton dominated by biomass due to Cladocera and Copepoda, in the water reservoir—due to the Copepoda. The dam area of the water reservoir had the highest species richness of zooplankton among all studied sites. The greatest number and biomass of zooplankton within a waterbody are noted in upper part, where a sedimentation zone had formed, and as a whole for the system of the investigated waterbodies, the maximum quantity indices are typical of lake communities. It is revealed that the starkest interannual changes in zooplankton were observed in the shallow lake: the number of species decreased—in the littoral zone at the expense of Rotifera, and in the center, the biomass increased at the expense of Cladocera; in deep-water area of the dam area of the reservoir, conversely, the number of species, as well as the number and biomass of the community, increased due to Copepoda.

Extended spectrum beta-lactamase producing Shiga-toxin producing-Escherichia coli in piglets, humans and water sources in North East region of India.

Extended spectrum β-lactamases (ESBL) producing Shiga toxin producing E. coli (STEC) are posing a constant threat to public health throughout the world leading to serious infections and raising key therapeutic issues. A total of 219 fecal samples were collected from piglets with diarrheoa, pig farmers and water sources in North East India; and were processed for isolation of Escherichia coli. The isolates were screened for antimicrobial resistance and suspected isolates for ESBLs production by double-disk synergy test (DDST). Escherichia coli isolates positive for DDST were subjected for detection of selected ESBL/beta-lactamase genes and virulence associated genes by PCR. By DDST, 337 (67·94%) E. coli isolates were detected as ESBLs producer, of which 211 (66·98%), 117 (70·91%) and 9 (56·25%) isolates were from piglets, humans and water sources respectively. A total of 64 (12·90%) isolates were recorded as STEC, of which 48 (9·68%), 6 (1·21%) and 10 (2·02%) were from human, piglets and water respectively. Majority of the STEC isolates (64·06%) possessed multiple virulence genes, of which 59·38% also harboured ESBL/beta-lactamase genes with 32·81% STEC isolates being positive for multiple ESBL/beta-lactamase genes. SIGNIFICANCE AND IMPACT OF THE STUDY: Multidrug resistant (MDR) enteric bacteria are global concern. Association of MDR traits in STEC isolates are another rising issue in human and animal health perspective. The interaction of such organisms among the human, domestic animals and adjoining water sources require to be analysed systematically. The present study exhibited the possible transmission of MDR-STEC among the human, domestic animals and water sources in the North eastern states of India. To the best of our knowledge, this is the first report of such kind in India.

Novel, Repeated Surveys Reveal New Insights on Sediment Flux Through a Narrow Strait, Bohai, China

AbstractStraits are both a choke point and passage through which material and energy are exchanged between two adjoining water bodies. Understanding the mechanisms that drive these exchanges therefore is vital to quantifying the water and sediment budgets in regional and global oceans. Here we present a study in which a novel, phase‐averaging method was employed to better estimate the net‐suspended sediment fluxes through the entire Bohai Strait, the only passage for the massive Yellow River‐delivered sediment to leave the enclosed Bohai Sea for the open Yellow Sea. In winter, the transport through the strait was nearly barotropic in waters well mixed by the energetic winter monsoons. The transport became primarily baroclinic (opposite directions between upper and lower layers) in spring due to stratification, especially in the southern part of the strait. Intermittent but frequent southerly winds in northerly dominated winters were responsible for a net westward sediment transport into the Bohai Sea, a finding contrary to a status quo view. Hence, previous studies in which these intermittent southerly wind busts were not included are believed to have overestimated the sediments export from the Bohai Sea.

Studies of Electrochemical CO2 Reduction in Membrane-Electrode Assemblies

Gas-diffusion electrodes (GDEs) for electrochemical CO2 reduction allow for an order-of-magnitude increase in obtainable limiting current densities (~100 mA/cm2) compared to planar systems (~10 mA/cm2) due to the increase in CO2 flux, catalyst surface area, and reduction in diffusion length. Despite this improvement, aqueous GDE systems suffer from extensive catalyst dissolution/delamination and membrane degradation under operating conditions, as well as exhibit significant ohmic resistances stemming from their electrolyte layers. These characteristics limit the current densities that can be achieved at applied overpotentials and render them impractical for industrial implementation. Membrane-electrode assemblies (MEAs), consisting of humidified gaseous feeds at one or both electrodes and no aqueous electrolyte between the electrodes (i.e. only using a solid ion-conducting polymer or ionomer as an electrolyte), can overcome the limitations of the aqueous GDE. In this poster, two MEA cell designs will be addressed: Full-MEA (humidified gaseous feeds at both the anode and cathode) and Exchange-MEA (humidified gaseous feed at the cathode and an adjoining water or salt solution, e.g. KHCO3 or KOH, at the anode to provide hydration and a source of ions). The experimental performance results obtained from the near-optimized vapor-fed Full-MEA and H2O Exchange-MEA systems for CO2RR at ambient temperature and pressure conditions and the details of our ongoing work in building a fully integrated, tandem/cascade catalysis device are described. This poster also details plans for future investigations in exploring critical fabrication, operating conditions, and MEA properties. Acknowledgements This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC0004993. We would also like to thank Nemanja Danilovic, Kun Jiang, Julie Fornaciari, Yagya Regmi, Douglas Kushner, and Christianna Lininger for their help, discussions, and guidance in the course of this research project.

Gate-Controlled Sum-Frequency Vibrational Spectroscopy for Probing Charged Oxide/Water Interfaces.

The rich chemistry of oxide/aqueous interfaces originates from the interfacial layer formed by surface charges and adjoining water molecules. Yet not much is clear about such layers, because they are difficult to access, and measurements unavoidably collect signals from the diffuse layer nearby, which is perturbed by the surface potential extending into the bulk water. Here we show that gating of a semiconductor/oxide/water junction can effectively vary the surface charge density at the oxide/water interface but keep the surface potential low and barely varying, allowing effective removal of the diffuse layer contribution. With sum-frequency vibrational spectroscopy on a silicon/silica/deionized-water model junction, the variation of the bonded layer water structure in response to surface charging can be readily detected. This new scheme is generally applicable to all oxide/water interfaces, providing opportunities for future investigations at a deeper molecular level.

Optimization of salinity intrusion control through freshwater and tidal inlet modifications for the Indus River Estuary

Increasing salinity levels in the tidal rivers are becoming a significant challenge to inland water quality. Salinization of the adjoining water resources and agricultural lands have prompted the water managers to optimize the solutions for mitigation of adverse effects. Keeping this in view, a hydrodynamic model coupled with a water quality model was used to analyze the propagation of tides from the Arabian Sea into the Indus River and their subsequent effect over longitudinal salinity distribution. Field observations of hydraulic parameters and salinity were used for validation of the model predictions in dry (no river flow) and wet (specific river flow) hydrological conditions. Results suggest that the tidal amplitude dissipates landward; salinity intrudes about 58 km (near Dandari) into the Indus River Estuary (IRE) at spring tide. Salinity in the proximity of Dandari point is sensitive to variations in fresh water supplies. A complete neap-spring tidal cycle was chosen for scenario-based evaluation of the impact of fresh water over the longitudinal salinity distribution. A daily river discharge 250 m3/s was found optimum for limiting the salinity interface (≤1) up to 31 km from the estuary mouth. In addition, tidal inlet modifications based on the theoretical framework of stable channel design combined with the optimum river discharge were tested. The cross-sectional modifications based on the regime/Lacey theory proven better and salinity interface was further pushed back up to 27 km. Thus, it is maintained that synergic impact of the optimized freshwater quantity and the estuary mouth modifications are considered as one of the pragmatic solutions for control of salinity intrusion and achieving the specific environmental conditions along the alluvial estuary.

Chemical Characteristics of Buffer Zone Sediments And Implications on Adjoining Water in Diyawanna Lake

Diyawanna Lake is one of the major fresh water body located in the middle of Sri Jayewardenapura Kotte. Most of surrounding area of the lake consists of marshlands. During the recent past several reclamation and development activities going on around the lake. In addition, sediments from surface runoff are finally accumulating in the lake margin (buffer zone). However, there is no any study done on sediment quality and impacts of them on adjoining water, especially in the buffer zone of such a fresh water body. Therefore, main aim of this study is to investigate quality of the sediment accumulated in the buffer zone of the lake and also to study the possible impacts on lake water from the sediments due to biogeochemical reactions in the zone. Thirty three water samples were collected during dry period and samples were analysed for pH, electrical conductivity (EC), oxidation reduction potential (ORP), salinity, total dissolved solid (TDS), NO3 -, PO4 3-, SO4 2-, Cl-, alkalinity, hardness, Na, K, Ca, Mg, Cd, Cr, Cu, Fe, Pb, Mn, Zn and Ni. In addition, black organic sediment samples were collected from selected locations and tested for pH, ORP, EC, organic carbon, total organic matter, NO-3, PO4 -3, Na, K, Ca, Mg, Cd, Cr, Cu, Fe, Pb, Mn, Zn and Ni. Average values of pH, EC, ORP, TDS, NO3 -, PO4 3-, SO4 2-, Cl-, alkalinity, hardness, Na, K, Ca, Mg, Cu, Zn and Fe for the lake water are 7.4, 222 μS/cm, -37 mV, 222 mg/l, 0.11 ppm, 15.00 ppm, 1.43 ppm, 20.00 ppm, 0.0002 ppm, 772 ppm, 16 ppm, 10 ppm, 36 ppm, 21 ppm, 0.001 ppm, 0.009 ppm and 0.14 ppm respectively. However, element Cd, Pb, Mn and Ni were not detected. Piper classification for the lake water indicate CaSO4 type, which reflect typical gypsum type of waters with impact of mine drainage due to mineral pyrite in soil. Also, sulfur emitted by the vehicles may react with water to form sulfuric acid. In addition, gypsum type of water may also due to accumulation of building materials such as cement. Therefore reason for the CaSO4 type of water may be due to several sources in the area. In addition, compared to WHO guidelines only Cr (0.58 ppm) present in the water is considerably high, this may be due to direct discharge of urban dust into the lake. Average values of pH (6.1), ORP (54 mV), EC (122 μS/cm), organic carbon (3.1%), total organic matter (18%), nitrate (0.93 ppm), phosphate (12 ppm), Na (3.5 g/kg), K (11 g/kg), Ca (73 mg/kg), Mg (84 mg/kg), Cd (40 mg/kg), Cr (391 mg/kg), Cu (134 mg/kg), Fe (44 g/kg), Pb (833 mg/kg), Mn (157 mg/kg), Ni (196 mg/kg) and Zn (33 g/kg) in the sediments are considerably different value than the water. Compare with Canadian Environment Quality guidelines average values of Cd, Cr, Pb and Zn are higher in the sediments. This is mainly due to accumulation of those elements from runoff water. In general, it can be concluded that prevailing physical conditions of the lake water is controlling leaching of heavy metals from sediments to water. Conversely, anthropogenic sources seem to be increase accumulation of heavy metals in the buffer zone sediments. Keywords: Diyawanna Lake, Water quality, Sediment quality

Dissolved and solid-phase arsenic fate in an arsenic-enriched aquifer in the river Brahmaputra alluvial plain.

Dissolved arsenic mobility in the environment is controlled by its associations with solid-phase As and other minerals by chemodynamics of adsorptions and co-precipitation. Arsenic mobilization potential and mechanisms in the groundwater of a part of the river Brahmaputra alluvial plain in India were inferred from aqueous and solid-phase geochemical analyses of groundwater samples and sediment cores from various depths. Sediments were analyzed for key parameters, e.g., total and sequentially extracted Fe, As, and Mn; organic carbon content; carbonate phases; and specific surface area, while groundwater samples collected from close proximity of the drilled bore well were analyzed for major and trace element hydrogeochemistry. Result shows Mn- and Fe-oxyhydroxides as the major leachable As solid phases. Median total leachable solid-phase As was found to be ~9.50mg/kg, while groundwater As ranged between 0.05 and 0.44mg/L from adjoining water wells. Morphological and mineralogical studies of the aquifer sediments conducted using scanning electronic microscope energy-dispersive X-ray (SEM-EDX) and X-ray diffraction (XRD) analysis indicate the major presence of Fe- and Mn-oxyhydroxides. Sequential leaching experiments along with the mineralogical studies suggest that bacterially mediated, reductive dissolution of MnOOH and FeOOH is probably an important mechanism for releasing As into the groundwater from the sediments.

Baseline Environmental Impact Assessment of Phytodiversity in a Proposed Floor Sweeping Canalization of Abonnema Wharf Adjoining Water Ways and Aiteo Jetty Development Project

This report describes the results of an ecological baseline impact assessment study of the Aiteo operational area. This baseline has merit based on the context of a proposed canalization / floor sweeping of adjoining water ways, construction and development of a Jetty project in Abonnema Wharf Area, Port Harcourt, Rivers State. This study was aimed at establishing the existing conditions of the environment and envisaged degrees of potential impact on the area against which future changes may be assessed and secondly, reviewing the possible risks to the environment likely to arise from the canalization, construction and operation of the Jetty. A standard procedure of integrated field study was adapted to qualitatively and quantitatively assess floristic profile of the vegetation in the area. The result of the study has recorded climax mangrove forest vegetation, though with some levels of heterogeneity and discrete homogeneity as a result of imbalances in the local environmental conditions incursioned by both natural and human factors. However, the ecosystem still maintains the status of abundance, richness and evenness with obvious similarity in floristic composition and forest structure to that in tropical forest elsewhere in the world. It is obvious that the Abonnema wharf forest ecosystem is gradually being destroyed without proper articulation of its wealth of flora diversity. Its mangrove forest vegetation is variable in size, form and plant community structure. It is one of the most productive ecosystems with enormous benefits to the people in this part of Niger Delta, Nigeria, and the store house of bio- diversity providing suitable habitats for plants, important areas for rare and endangered wildlife. The application of phyto-sociological indices of assessment for the mangrove vegetation complex in terms of species diversity in richness and evenness, density, abundance, IVI, distribution pattern and defined vegetation structure has been highlighted, indicating the area to be of high conservation potential if protected from both natural and human perturbation.

Non-segregated municipal solid waste in an open dumping ground: a potential contaminant in relation to environmental health

The present article discusses an overview on the contamination of non-segregated open municipal solid waste (MSW) in and around a dumping site at Garchuk in Guwahati city, Assam, India. Analysis showed depth-wise variations in the concentrations of selected heavy metals in MSW and their subsequent accumulations with increasing depths. Zinc was the most abundant heavy metal in MSW. Six-step selective sequential extractions revealed that most of the heavy metals in MSW were in the residual phase except zinc. Analysis of the leachate from MSW showed high concentrations of fluoride, chloride, ammonium–nitrogen and the ratio of biological oxygen demand/chemical oxygen demand. Concentrations of all the heavy metals in the leachates were higher than the Indian national effluent standards. High amounts of biological oxygen demand, heavy metals, total and fecal coliforms in water samples from the adjoining water body (Deepor Beel, a Ramsar site) of the MSW dumping site indicated its unsuitability for domestic use. Principle component analysis showed that influence of MSW leachate was the major source of water contamination in Deepor Beel. Though accumulation of heavy metals in different vegetables growing in MSW dumping site did not exceed the recommended maximum intake, it was a significant additional source of heavy metals in cooked human diet.

Laboratory Evaluation of the Geotechnical Characteristics of Wastewater Biosolids in Road Embankments

An extensive suite of geotechnical laboratory tests were undertaken on wastewater biosolids to evaluate their sustainable usage as a fill material in road embankments. Geotechnical tests undertaken include particle size distribution, specific gravity, Atterberg limits, compaction, consolidation, hydraulic conductivity, California bearing ratio (CBR), field vane shear, direct shear, and triaxial shear. The geotechnical tests indicated that biosolids are equivalent to organic fine-grained soils of medium to high plasticity with high moisture content and liquid limit values. Consolidation tests indicate that biosolids have similar consolidation characteristics to that of organic soils. Shear strength tests on compacted biosolids samples indicated relatively high internal friction angles, comparable to that of inorganic silts. Compacted biosolids samples exhibit a modest cohesion comparable to organic clays. CBR tests results indicate high deformation potential of biosolids. Chemical and environmental assessment tests indicated that heavy metals, dichloro diphenyl trichloroethane (DDT) and organochlorine pesticides concentration along with pathogens (bacteria, viruses, or parasites) results were within acceptable limits for usage in geotechnical applications. With regards to contaminants containing nitrogen, phosphorus, and total organic carbon, the biosolids were found to require special protection in the event there is potential leaching/flow to adjoining water bodies. The geotechnical testing results indicate that untreated biosolids have insufficient bearing capacity to enable its usage as a fill material. The biosolids will have to be stabilized with an additive or blended with a high-quality material to enhance its geotechnical properties to enable it to be considered as an engineering fill material.

Responsiveness of Ada Sea Defence Project to salt water intrusion associated with sea level rise

The Ada peninsular in Ghana has suffered rapid coastal erosion and inundation for over half a century, accompanied by loss of property and livelihoods, economic stagnation and salt water intrusion. Government intervened to respond to these threats by implementing a sea defence project. A preliminary assessment indicates the project will deal with some urgent needs of property loss reduction and invigorate livelihood and economic opportunities. However, it will have minimal beneficial impacts on groundwater salinization, and may actually intensify salinity of surface water in the Volta River and adjoining water points by shifting salinity intrusion further upstream to affect hitherto salinity-free areas. The spatial reach of the salinity shift is uncertain. The potential for further sea level rise will aggravate and accentuate the region’s water scarcity dilemma if a coherent water management strategy is not sort sooner. The project demonstrates the limitations of employing static, narrow objectively designed sea defence project as a response to coastal erosion and inundation, because it lacks the capacity to deal with dynamism, complexity and multi-dimensional impacts associated with climate change related sea level rise.

The Genus Dinophysis Ehrenb. (Dinophyta) in the Ukrainian Black Sea Coastal Waters: Species Composition, Distribution, Dynamics

Results of long-term original researches and the literary data on species diversity of the genus Dinophysis of the Ukrainian coast of the Black Sea are generalized. This genus incorporates 25 species. Dinophysis is represented by 21 species in the Crimean coast, and for the northwestern portion of the Ukrainian Black Sea area 17 species of this genus were cited. Dinophysis acuminata, D. caudata, and D. rotundata are dominating species; they are most common in the northwestern Black Sea. Species of the genus occur in the plankton from May to November at water surface temperatures of 7.5-26.6 °С and salinity 9.7-17.6o/oo. The maximum values of species number were recorded in August, minimum values in November. Seasonal changes of a complex of species of the given genus and peculiarities of their spatial distribution in the Odessa Bay and adjoining water area are described. The obtained data present evidence for the necessity of permanent hydrobiological control in the development of potentially toxic microalgae of genus Dinophysis, which are indicators of high organic pollution of the water environment.