Background: Uniquely synthesised titanium dioxide (TiO2) with high-energy {001} exposed facets denoted HF8 was used for the photocatalytic degradation of microcystin-LR (MC-LR) under ultraviolet irradiation at 365 nm. Methods: The influence of various conditions including environmental pH, nutrient anions, TiO2 dose, and MC-LR concentration was studied, and concentration of MC-LR measured using liquid chromatography-tandem mass spectrometry. Results: Within 120 min, 72.6% of an environmentally relevant MC-LR concentration (120 µg/L) was degraded under pH conditions ranging from 3 to 11. Stability tests revealed no loss of TiO2 activity after four applications of the same dose, indicating its stability, reusability, and potential to be re-used for sustainable remediation of MC-LR in eutrophic waters. Mechanism studies suggested that the reaction obeyed the pseudo-first-order equation and that hydroxyl radicals are the major reactive intermediate contributing to the reaction. The structure elucidation of intermediates suggested that hydroxylation and bond cleavage between the Adda chain and Mdha site could be the initiation of reactions in the degradation of MC-LR by HF8 TiO2. Conclusion: The results present a fast, sustainable, and practical method using modified TiO2 to improve MC-LR remediation. Keywords: Degradation, Microcystin-LR, Photocatalysis, Titanium dioxide

Methane (CH4) and Nitrous Oxide (N2O), being potent greenhouse gases (GHG) contribute largely to global warming and climate change. The association of plant factors of rice plants on Global Warming Potential (GWP) and Greenhouse Gas Intensity (GHGI) are not well documented. To address the problem of climate change, global warming need to be mitigated by cutting down the emission of CH4 and N2O at its source. A 02 year field experiment was conducted during April-September of 2016 and 2017 which includes 08 pre monsoon (Ahu) rice varieties: Dikhow, Disang, Jaya, Kolong, Kopilee, Lachit, Swabhagi and Abhishek to estimate their GWP, GHGI and Carbon Equivalent Emission (CEE). CH4 and N2O flux throughout the cropping season were measured using static chamber technique. Investigation shows significant differences in seasonal GHG emission, GWP, GHGI, photosynthetic efficiency, transpiration rate and grain productivity among the rice varieties. A good correlation of CH4 and N2O emission was recorded with GWP, GHGI, CEE and transpiration rate of the varieties. GWP and GHGI of the varieties Abhishek and Lachit were relatively low while grain productivity was high during both the years of experimentation. The results from this study suggest that cultivation of rice varieties with lower GHG emission efficiency accompanied by higher grain productivity can be an effective environment friendly biological mitigation strategy for emission reduction of GHG and global warming. Key words: Methane, Nitrous Oxide, global warming potential, greenhouse gas intensity, carbon emission efficiency, photosynthetic efficiency.

Clays are used widely for cosmetics and pharmaceutical purposes because of their physical properties and chemical components. In addition, they contain some heavy metals which are significant toxicants and carcinogens. In this study, 8 Nigerian clays from 2 communities in Abia State, Southeastern Nigeria, were analysed for their heavy metal content. The samples were digested using aqua regia (HNO3 and HCl). Cu, Co, Pb, Cd, and Zn were determined in the digested samples using atomic absorption spectrophotometer, Perkin Elmer Analyst 200. The physicochemical properties of the clays such as pH, EC and CEC were also investigated. The concentration of Zn ranged from 14.42 to 41.28mg/kg; Cd ranged 0.06 to 0.11mg/kg as it was detected in only three out of the eight samples. Pb was detected in only one of the samples (4.92mg/kg); Co range from 0.02 to 0.5mg/kg; Cu showed the highest concentration (80.66 to 683.34mg/kg). The CEC of the clay samples were also determined (Na+, K+, Mg2+, Ca2+) and were found to be low in the range of 0.038 to 2.558meq/100g. The pH ranged from 6.58 to 8.08 while EC ranged from 1.41 to 2310 µs/cm. The use for cosmetics and pharmaceuticals of the clay samples that contains Pb and Cd should be discouraged since they represent important exposure source to these carcinogens.

The terrain segmentation to zones of high to low landslide risk is key issue in urban and technical works planning in western Greece where landslide hazard is a key factor in loss of properties while significant damages to road network take place. The study area includes the prefecture authority of Achaia where landslide hazard is amplified by the lithology (flysch and alluvial deposits), fracture systems, down-cutting erosion, severe rainfalls, and earthquakes. The landslide database of the Institute for Geology and Mineral Exploration of Greece is used to derive the occurrence of landslides within the study area. Totally 82 sites of landslide occurrence were considered within the study area. The innovative idea in this research effort is to use terrain attributes: (a) That apply to each grid point of a digital elevation model and (b) They refer to an extended neighbor that is relevant to each grid point under consideration. So in this approach an extended neighbor that varies per grid point per terrain attribute as well as shape terrain attributes are used to characterize the geomorphometry of the study area. Under a trial and error procedure 13 terrain attributes (Channel Network Distance, Profile Curvature, Length Slope Factor, Valley Depth, Downslope Curvature, Convergence Index, Flow Path Length, Plan Curvature, Positive Openness, Topo Wetness Index, Total Catchment Area, Mass Balance Index, Upslope Curvature) presenting the minimum correlation between them were selected. K-means clustering defined 8 terrain classes. Each terrain class is represented by the centroid vector and its spatial extent. The percent landslide occurrence within the percent area occupied by each terrain class, is used to define a new landslide susceptibility index that is useful for hazard/risk assessment, land use and land cover studies as well as rural and urban planning within the study area. Keywords: landslides, digital elevation model, geomorphometrical characterization, urban planning.