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This study investigates the adsorption kinetics and removal conditions of copper by walnut tree sawdust from synthetic solutions in the batch and fixed bed reactors. The selected experimental parameters for the batch reactor were concentration, solution pH, adsorbent amount and temperature. The optimum batch reactor conditions were applied to the fixed bed reactor. The experimental parameters of the fixed bed reactor were flow rate, bed height, and concentration. The optimum removal conditions for copper removal in the batch reactor were determined as pH (5), temperature (25oC), concentration (25 mg/L), and adsorbent dosage (10 g/L). The kinetic data obtained from the batch reactor were analyzed by the pseudo-first-order and the pseudo-second-order kinetic models and the kinetic data were successfully correlated with the pseudo-second-order model. Activation energy of the process was calculated to be 15.79 kJ/mol. The optimum parameters for the fixed bed reactor were designated as 0.5 mL/min flow rate, 100 mg/L concentration and 15 cm bed height. The kinetic data obtained from the fixed bed reactor were analyzed with the Yoon-Nelson and Thomas kinetic models. The fixed bed kinetics could be described with the Thomas model. Maximum adsorption capacity was calculated as 6.24 mg/g in the fixed bed reactor.

The peculiarity of the lower atmosphere of south west region of Nigeria was explored using theoretical and experimental approach. In the theoretical approach, the reconstruction of 1D model as an extraction from the 3D aerosol dispersion model was used to examine the physics of the recirculation theory. The experimental approach which consists of obtaining dataset from ground instruments was used to provide on-site guide for developing the new recirculation theories. The data set was obtained from the Davis weather station, Nigeria Meteorological agency and Multi-angle Imaging Spectro-radiometer (MISR). We looked at the main drivers of recirculation and propounded that recirculation is a complex process which triggers a reordering of the mixing layer- a key factor for initiating the type of rainfall in this region.

This study was conducted to determine phytoextraction efficiency of Puccinellia distans (Jacq.) Parl. for Pb (450 mg kg-1 Pb(NO3)2) and the application of EDTA and DTPA (2.5DTPA, 5DTPA, 2.5EDTA, 5EDTA, 2.5EDTA+2.5DTPA, 2.5EDTA+5DTPA, 5EDTA+2.5DTPA, 5EDTA+5DTPA) on the Pb uptake and the potential for leaching of Pb during the phytoextraction process. Bioconcentration factor (BCF), translocation factor (TF) and tolerance index (TI) were calculated to determine Pb phytoextraction efficiency. Results showed that DTPA appeared to be more toxic to the plant than EDTA. Plants with combined treatments of EDTA and DTPA exhibited higher decrease in biomass compared to those that had received a treatment of EDTA and DTPA alone. 5DTPA and 5EDTA were the most efficient ratio for increasing concentrations of Pb in the shoots. DTPA showed much higher efficiency than EDTA. BCF of the shoot was relatively higher than the BCF of root. Thus, the plant would be applicable for Pb phytoextraction. Addition of chelates had virtually significant effect on Pb uptake by the plant and elevated Pb concentration in the soil and plant parts. Optimum phytoextraction was observed when 5mg kg−1 EDTA and DTPA was added alone in single dosage to reduce the Pb–chelates leaching risk.

Salinity is a key environmental factor for the successful application of anammox technology in wastewater treatment, because it impacts the activity and the community structure of anammox bacteria. In this study, the changes in activity and population shifts of an anammox system response to the elevated salt stress (0, 5, 10, 20, 30 and 40 g NaCl/L) were studied.

The results show that the anammox reactor performed effectively even at 30 g NaCl/L salinity after an appropriate acclimatization. The nitrogen removal rate maintained at 0.28 g N L-1d-1 with the nitrogen removal efficiency of 76%, though the high environmental salinity might inhibit the anammox growth in the long-term operation. 16S rRNA high-throughput sequencing results revealed that Ca. Brocadia, Ca. Jettenia and Ca. Kuenenia were the dominant anammox bacteria at all salinities. Ca. Brocadia and Ca. Jettenia were quite sensitive to salinity, and 5 g NaCl/L dosing could cause a sharp decline in their abundance. Nevertheless, these three anammox genus finally survived in the system with a steady specific anammox activity of 0.13 g N g VSS-1d-1. Specially, a novel cluster, Brocadiaceae_unclassified, which possibly belongs to anammox bacteria, became the dominant genus at the salinity over 20 g NaCl/L and likely contributed partially to the nitrogen removals. Our findings elucidated the inherent link between community dynamics and anammox system performance and stability under salty environment, and proved that anammox technologies can be an effective technology for treatment of saline ammonia-rich wastewater.