Deji Reservoir is situated in the middle of Taiwan on the upstream catchment of the Dajia stream with an area of over 60,160 ha. The embankment stands 180 m high and is the tallest concrete arch dam in Taiwan. This dam stores 1.7 billion cubic meters of valid volume water. It provides over 370 million kilowatt-hours of electricity annually. It is also an important facility for operating flood control, hydroelectricity, irrigation, public water supply, etc. Seventy-two percent of the terrain is at 2,000- to 3,000-m altitude, and 5.2% is above 3,200-m altitude. More than 59% of the area is covered with steep topography of 55% slope. Only 7.9% of the area is shown with gentle slopes of less than 30% slope, which are located among the two banks of main streams with the altitudes ranging from 1,500 to 2,500 m. Most of the gentle slopes are used for temperate zone fruit, vegetable, and tea plantations. This land-use immediately adjoins a reservoir catchment region, resulting in an enormous impact on the mountainous environment. This study reviewed human-developed land-use area to properly address and evaluate norms for mitigating the impacts on the reservoir. The initial investigation brought up the parameters of gradient, slope movement types and processes, distance to the reservoir, location of developed area and distance with the farm road, etc. Local investigation and global information system technology were conducted in this research. We focused on segregating the terrain types of indisposed land-use. A different land-use management strategy is also analyzed.

This study investigated sludge granulation inoculated with various mixtures of aerobic and anaerobic sludge at low dissolved oxygen (DO; 0.3-0.6 mg/l) or aerobic (>2.5 mg/l) conditions in four parallel flow reactor systems. Formation of high-density coupled granules was achieved in the reactor system inoculated with anaerobic and aerobic sludge seeds (1:1 mass ratio) at low DO concentrations, with a mean size of 2.5 mm after only 27 days of cultivation. The highest ratio of protein (PN) to polysaccharide (PS; 3.3) was observed for the coupled sludge compared to granules cultivated under aerobic conditions. The PN/PS ratio correlated well with high hydrophobicity, low sludge volumetric index, and compact granular structure. Activity tests of the specific anaerobic and aerobic biomass confirmed that anaerobes and aerobes coexisted in the same coupled granule. Based on the optical microscopic and SEM observations, the process of coupled granule formation was proposed.

The decomposition of gaseous isopropanol (IPA) by UV/TiO₂ process in an annular photoreactor was studied under various conditions such as UV light intensity and inlet IPA concentrations. In order to impede the rapid electron/hole recombination during photoreaction, the Ag deposited on TiO₂ photocatalysts were prepared by a photodeposition process. This study was aimed at applying the photocatalytic oxidation using the Ag/TiO₂ and pure TiO₂ catalysts to remove gaseous IPA. The PL analyses indicated that the silver on the surface of TiO₂ could inhibit the electron/holes recombination. For experiments conducted with gaseous IPA under UV light irradiation, the photocatalytic activity of Ag deposited TiO₂ surface was significantly superior to that of TiO₂ only ones.

Information on tradeoffs among water quantity and quality attributes at a watershed scale is important in developing effective watershed conservation policies. Assessment of these multiattribute tradeoffs, a focus of this study, is often a low priority in policy design. A combination of simulation modeling and statistical assessment was used to evaluate the significance of relationships among runoff, sediment, nitrate, and phosphorus loading in 115 subwatersheds of the Blackstone River Watershed in southern New England. We observed high variability in rates of runoff, nitrate, phosphorus, and sediment loading among subwatersheds. Results of the regression analysis indicate a high correlation between nitrate and surface runoff, emphasizing the importance of stormwater management in mitigating nutrient loads. A significant relationship exists between mineral phosphorus and sediment yield in watersheds that could inform strategies to mitigate eutrophication problems in phosphorus-limited systems such as some inland water bodies. The tradeoff analysis proposed can be used in policy design and to assess the implications of various policies to address multiple pollutants.

Changes in deposition exert effects on forests. Some evidence for a slow recovery of strongly alkalised forest soils after a reduction in alkaline pollution exists, but the recovery rate is little known. The objective of this study was to estimate temporal soil reaction changes. For this purpose, measurements of soil reaction under a beech forest near magnesite works in Central Slovakia were taken in 1991 and 2006, following the alkaline pollution reduction in 1992. As a result, the mean active soil reaction decreased from pH 7.8 to 6.6. Beyond the range of beech stemflow, which amplifies water and acid pollution inputs into soils locally, soil reaction dropped from pH 7.8 to 6.8. The effect of stemflow on local exchangeable reaction minima was detected even before the pollution reduction. The logarithmic function fitted on the pH data indicates considerable differences between neutralisation rates within and outside the stemflow zone.

The main purpose of this work was to conduct a kinetic study on cell growth and hexavalent chromium [Cr(VI)] removal by Candida sp. FGSFEP in a concentric draft-tube airlift bioreactor. The yeast was batch-cultivated in a 5.2-l airlift bioreactor containing culture medium with an initial Cr(VI) concentration of 1.5 mM. The maximum specific growth rate of Candida sp. FGSFEP in the airlift bioreactor was 0.0244 h⁻¹, which was 71.83% higher than that obtained in flasks. The yeast strain was capable of reducing 1.5 mM Cr(VI) completely and exhibited a high volumetric rate [1.64 mg Cr(VI) l⁻¹ h⁻¹], specific rate [0.95 mg Cr(VI) g⁻¹ biomass h⁻¹] and capacity [44.38 mg Cr(VI) g⁻¹ biomass] of Cr(VI) reduction in the airlift bioreactor, with values higher than those obtained in flasks. Therefore, culture of Candida sp. FGSFEP in a concentric draft-tube airlift bioreactor could be a promising technological alternative for the aerobic treatment of Cr(VI)-contaminated industrial effluents.

Field measurements were conducted using one to three sheets of a poly-tetrafluoroethylene (PTFE) membrane resistance-type passive sampler (N type sampler) and diffusion length resistance-type sampler (O type sampler) to compare sampling resistance. Acidic gases such as nitric acid (HNO₃), hydrochloric acid (HCl), sulfur dioxide (SO₂), ozone (O₃), ammonia (NH₃), nitrogen dioxide (NO₂), and nitrogen oxides (NO X ) were sampled using five types of capturing filter paper: plain polyamide filter ([Greek Phi symbol]47 mm) and cellulose filters ([Greek Phi symbol]14.5 mm) impregnated with NaNO₂ + K₂CO₃, H₃PO₄, triethanolamine (TEA), and TEA + 3-oxo-2-phenyl-4,4,5,5-tetramethylimidazolin-1-oxyl (PTIO). Four sets of the samplers were exposed to the atmosphere for 4 or 5 weeks through four seasons in FY 2006. The amount of gas components captured occurred in the order of NO X > O₃ > NO₂ > NH₃ > SO₂ > HCl > HNO₃ for all of the filters in spring and autumn. However, the amount of NH₃ captured was large in summer and the amount of NO X was large in winter. The relative standard deviations (RSDs) were less than 10% except for NH₃ with the O type sampler in spring and autumn, and for HCl of both type samplers in winter. The RSDs were not dependent on the numbers of PTFE sheets for gas species and season. When the N type sampler mounted on one PTFE sheet was normalized to unit, the resistance values of two and three PTFE sheets for HNO₃ were 2.3-2.4 and 4.2-6.1, respectively, while the values of two and three sheets for SO₂, O₃, HCl, and NH₃, were 1.1-1.5 and 1.3-1.9, respectively. There was little variation in resistance for NO₂ and NO X , as shown by the values of 1.0-1.1 and 0.9-1.2, respectively. For comparison with the O type sampler, the resistances values for SO₂, O₃, HCl, NH₃, NO₂ and NOX were 4.9-5.8, 2.5-3.2, 2.7-4.5, 4.1-12.6, 1.4-1.9, and 1.2-2.4, respectively. The resistance values of the O type sampler were larger than those of the N type samplers. The collection of HNO₃ was decreased 25% per PTFE sheet, while the decreases for SO₂, O₃, HCl and NH₃ were moderate at 12-17%. In contrast, collection of NO₂ and NO X was minimally affected by the number of PTFE sheets. The concentration of HNO₃, SO₂, HCl and NH₃ in the N type passive sampling method was compared with that of the four-stage filter pack method. The passive method for HNO₃, SO₂ and HCl was in fair agreement with the filter pack method. For NH₃, the concentration by passive method was lower than that by the active method.

Short term influence of silica, palladium, gold and copper nanoparticles on a soil microbial community and the germination of lettuce seeds are investigated in this study at two different concentrations of nanoparticles. Results show a statistically insignificant influence of the nanoparticles in the soil on the number of colony forming units, peak areas of methyl ester of fatty acids in the FAME profile or on the total soil community metabolic fingerprint (P > 0.05). Also, all nanoparticles tested in the study influenced the growth of lettuce seeds as measured through shoot/root ratios of the germinated plant (P < 0.05).

In this paper a novel methodology for estimating the parameters for an extended biokinetic model (Peev, Schönerklee, and De Wever, Water Science and Technology, 2004) of micropollutant removal in wastewater treatment is presented. In particular, the work concentrates on parameter estimation of the micropollutant degradation sub-model by specialised microorganisms in the case when only substrate measurement data are available. We have proven the structural identifiability of the model and have developed a new approach allowing practical identifiability on the basis of multiple substrate degradation curves with different initial concentrations. Experimental and related numerical methods for unambiguous parameter estimation have been developed. Finally, by means of simulated pseudo-experiments we have found convincing indications that the proposed algorithm is stable and yields appropriate parameter estimates even in unfavourable regimes.