Asian Journal of Environment & Ecology

Engineering structures are constantly subject to damage caused by biological activities such as the action of insects, penetration of roots and fluids. Because of this, we conducted a critical study on how these activities contribute to the collapse of these structures in Nigeria. The damage caused by biological activities was evaluated in fifteen buildings in Cross River State, of these buildings six showed damage caused by termites, two of the failed engineering structures were linked to development of roots of plants, and the remaining seven were linked to poor quality building materials, poor compaction, lack of supervision, poor engineering design. Others ten structurally failed buildings were examined in the Federal Capital Territory Abuja, Nigeria, of these four were linked to biological activities of termites, with subsurface porosity showing evidence of surface water discharge zones, two of the failed structures were linked to the growth activities of roots of trees, and four to poor construction design. The road that links Cross River State to Abuja had more than 80 points of failure, the majority of which were linked to poor compaction of road foundation, root of plants and fluid interference. Such damage could be prevented through: thorough investigation of biological activities existing and likely to exist around the environment before the establishment of the engineering structure and over the years; use of bio-resistant materials, such as nano materials incorporated coatings with novel functionalities should be used in the construction of structures; protection of engineering structures from fluid penetration into foundations; and engineering structures must follow the global best practices guide lines, provided by ‘Society of Structural Engineers’.

The effectiveness of three different extractants soil mixtures—HCl, HCl + H₂S0₄, and DTPA-TEA, in order to determine Si from soil and the forms of Silicon as influenced by different parent materials under acidic medium.

Seven forms of Silicon; namely water soluble, specifically adsorbed, oxides bound, organic matter bound, exchangeable, residual, total viz sequential fractionation.

Extractable Si value established in this study was (50.0 mg kg^-1), indicating negative effect on plant physiology. The physico-chemical properties decreased significantly with increase in soil depth vs soil parent materials. In addition, the forms of Si in the parent materials decreased in the pattern RES, bound residual fractions > EXC, soluble & exchangeable fractions > OM, organic matter fraction.

Among the properties the silt fraction, pH & OM significantly and positively correlated with the forms of silicon, with negative correlation vs clay which maybe due to silicon adsorption by clayey fraction of the soil (redox). Therefore the soil maybe be maintained and conserved for farming activities.

This study evaluated air pollution tolerance plants as well as anticipated performance indices of some medicinal plants growing in the Lokpaukwu rock quarrying area in order ascertain their suitability for green belt development. Two quarry locations A which is older and has a higher level of activity, and B were used for the study with a control location at Abia State University, Uturu. Out of the sixteen dominant plant species identified, five species; Alchornea cordifolia, Baphia pubescens, Napoleona imperialis, Nauclea latifolia and Vitex doniana. were randomly selected for the study. Leaf samples were randomly collected in triplicate from the lowest branch of each selected plants with similar characteristics. Relative water content of plants was significantly higher (p<0.05) at the study area suggesting stomatal occlusion by dust while chlorophyll content was significantly lower at the quarry sites, a clear indication of pollution stress. Chlorophyll content was also lower in all plants at site B, being significant in N. imperialis and V. doniana. N. imperialis had the highest APTI of 19.15 at the quarry site suggesting suitability for green belt development at the quarry site. Based on API, V. doniana is the most suitable for green belt development among the five plant species.

Diatoms are mostly aquatic plants, growing in various environmental conditions and habitat. Because of their high sensitivity to environmental variations and rapid response to degradation, they are used as biological indicators. This study aimed to analyses the physicochemical parameters and diatoms assemblages of waterfalls. This will allow determining the key environmental factors that are responsible for both diatoms and Podostemaceae spatial and temporal distribution in the studied area.Water and diatoms samples were taken respectively for the physicochemical and biological analysis. Diatoms samples were collected by scraping the bedrocks and submerged plants; diatoms were subsequently identified to the species level using a light microscope. For physicochemical data analysis, a principal component analysis approach was used while diatom’s data were submitted to a correspondence trophic analysis. A total of 169 diatom species were identified in both waterfalls. Podostemaceae poor waterfalls were more species-rich (127) than the rich ones (110). Podostemaceae poor and Podostemaceae rich waterfalls were characterized with low mineralization, low values of pH and oxygen saturated water. The observed assemblages were composed of oligotrophic to eutrophic species, acidophilic, neutrophilic and high to moderate oxygen saturated water taxa. The ecology of different species revealed that dissolved oxygen was the main parameter which controls the distribution of diatoms, and probably the Podostemaeceae one in the two type of waterfalls Podostemaceae poor waterfalls are characterized by Fragilariacapucina and Gomphonema gracile. Podostemacea rich waterfalls were characterized by Eunotiafaba, Eunotiarhomboïdea, Pinnularia microstauron, Gomphonema procerum and Gomphonema clavatum.

Hydrochemical characterization of groundwater quality in Nkalagu District, southeastern Nigeria was carried to determine the main factors controlling the chemistry of groundwater and its suitability for drinking and irrigation purposes. Sixty (60) groundwater samples collected from boreholes and hand-dug wells in different parts of the area were analyzed for a range of physiochemical parameters and heavy metal constituents. The results show that concentration of the major ions were in the order Cl^->HCO₃^->SO₄^2->NO₃^- and Na>Ca²⁺>Mg²⁺>K⁺. The groundwater samples are slightly acidic with pH of 5.28 to 8.04; moderately hard with TH of 112.88 to 467.78 mg/l. The district is mainly controlled by carbonate and silicate mineral weathering based on the available result. Three main flow regimes were identified with Q-mode cluster analysis. Based on the WQIanalysis results, the groundwater quality in the district was classified, generally as ‘poor’ to ‘excellent’ for drinking purpose. Groundwater quality for drinking purpose were noted to deteriorates as one move from west towards the east of the district, while the north and south part pf the study area indicated the best quality in the district. Groundwater quality for irrigation purpose showed excellent quality based on the United States Salinity Laboratory and Wilcox diagrams. For future use of groundwater resource in the district we recommend implementation rules and guidelines in the area to enhance health and preserve groundwater sources in the district.