To evaluate the effects of water velocity and artificial substratum characteristics on the growth rate and biomass accumulation of periphyton, an artificial stream mesocosm experiment was conducted using alternative water sources collected from the Mangwall Stream (MW), the Han River (HR), and bank filtration water (BFW) from the Han River in the Republic of Korea. The measured concentrations of organic matter and inorganic nutrients in the MW were higher than in the HR and BFW. The surface of tile is relatively smooth and nonporous, whereas the surfaces of concrete and pebble are rough with numerous isolated pores in which filamentous periphyton become immobilized against hydrodynamic shear stress and mat tensile strength. Compared with the periphyton biomass of the HR and BFW, the peak biomass in the MW was significantly higher due to higher nutrient concentrations in the MW. Reasonable linear relationships (R² ≥ 0.69) between water velocity and total periphyton biomass/growth rate were obtained, indicating that water velocities above critical values can cause a reduction in biomass accrual. In addition, reasonable relationships (R² ≥ 0.58) between specific surface area and total periphyton biomass were obtained for the HR and BFW, indicating that an increase in the specific surface area of the substratum can lead to an increase in periphyton biomass in a nutrient-poor water body. Principal components analysis (PCA) results indicate that nutrient concentrations were the first dominant limiting factor for the growth and accumulation of periphyton, and water velocity and the specific surface area of the substratum were determined to be potential limiting factors. Consequently, the growth rate and biomass accumulation of periphyton were considered to be a complex function of nutrient concentrations, water velocities, and substratum characteristics.

After the construction of waterworks automated meter reading (AMR) systems with a 15-mm diameter smart water meter developed in this study, both the feasibility of field application of waterworks AMR and the patterns of household water consumption were evaluated. Average reception rate was 94.1% due to the communication blackout, and one-to-one communication with RF UHF and Internet (i.e. TCP/IP) was found to be more stable in AMR systems than multiple-to-one communication with RF UHF, DCU, and Wibro. Household water consumption clearly showed seasonal periodicity due to weather factors. Based on the analysis of liters per capita day (LPCD) for 80 households, the LPCD values were found to decrease gradually as the number of residents increased due to the saving effects through common consumption (i.e. washing, cooking, cleaning, irrigation, etc.). Relative to LPCD values of 100 control households without AMR systems, the LPCD values of 80 pilot households with AMR systems were reduced by 5.3%. Consequently, the deployment of developed waterworks AMR systems integrating smart water metering and end-use water consumptions should be encouraged to conserve both water and energy for smarter cities.

The use of a calibrated two-component model with a single blocking parameter for both adsorption onto mineral surfaces and partitioning into soil organic matter of two nonpolar sorbates (i.e., 1,2,4-trichlorobenzene and benzene) was evaluated by using several humic acid (HA)-coated sands with different fractions of organic carbon (f_oc ) ranging from 0.006 to 0.154%. Sorption of nonpolar sorbates to both untreated and heated sands was nearly linear due to the reduction of heterogeneous adsorption potential by strongly adsorbed vicinal water molecules over hydrophilic mineral surfaces. Sorption of nonpolar sorbates to the HA-coated sands was also essentially linear, and resulted from a combination of adsorption onto mineral surfaces and partitioning into soil organic matter, with the dominance of either contribution depending on the properties of the sorbents (e.g., f_oc ) and the sorbates (e.g., K_ow ). Contrary to the previous studies suggesting that surface area is the only variable affecting the magnitude of the adsorption coefficient onto modified high-surface-area clay minerals, the difference in adsorptive affinity of nonpolar sorbates onto modified mineral surfaces (i.e., K_S,c ) relative to that for pure mineral surfaces (i.e., K_S ) also may be important for low-surface-area, coarse-grained model aquifer sands. However, the improvement in predicted sorption behavior by incorporating the blocking effect is insignificant for low-surface-area, coarse-grained model aquifer sands.

The roles of mineral-bound humic acid (HA) and mineral surfaces in the sorption of six nonpolar neutral organic compounds with relatively high aqueous solubility, S_w , (1,2,4-trichlorobenzene, 1,4-dichlorobenzene, chlorobenzene, m-xylene, toluene, and benzene) to low-surface-area (i.e., ≤ 1.2 m²/g) metal (hydr)oxide- and HA-coated sands with low organic carbon fractions (i.e., 0.006% ≤ f_oc ≤ 0.044%) were investigated using well-characterized mineral surfaces [i.e., α-FeO(OH)- or Al₂O₃- coated sands], terrestrial HA, and solutions with relatively constant pH and ionic strength. Sorption isotherms of all six compounds to low-surface-area metal (hydr)oxide-and HA-coated sands were practically linear (i.e., 0.898 ≤ n ≤ 1.06), and resulted from a combination of sorption to both mineral-bound HA and mineral surfaces, with the dominance of either contribution depending on the properties of the sorbents (e.g., f_oc ) and organic compounds (e.g., S_w and K_ow ). Compared to HA-associated high-surface-area, pure metal (hydr)oxides or clay minerals illustrating that loading levels of HA significantly impacted sorption affinity (i.e., K_oc ) and linearity (i.e., n) for particularly hydrophobic compounds (i.e., phenanthrene, anthracene and pyrene) due to the changes in fractionation, and structural and chemical properties of mineral-bound HA, the subsequent changes of sorption affinity and linearity appeared to be insignificant for the sorption of organic compounds with relatively high S_w to low-surface-area metal (hydr)oxide- and HA-coated sands with low f_oc values. Thus, the predictive models for the sorption of organic compounds with relatively high S_w to low-surface-area metal (hydr)oxide- and HA-coated sands may not be remarkably improved by incorporating the complex changes of sorption affinity and linearity caused by the changes in fractionation, and structural and chemical properties of mineral-bound HA, although the mineral surfaces apparently caused physical and chemical changes of HA, and vice versa during adsorption onto mineral surfaces.