pH monitoring data for public water bodies in Niigata and Gifu prefectures in central Japan were tested by the nonparametric seasonal Mann-Kendall method to evaluate long-term acidification. A significant long-term declining trend in river water pH was found in several watersheds in Niigata and Gifu prefectures. In Niigata, the declining trend was observed only in areas receiving drainage from granitic rocks, and the acid neutralizing capacity of the river waters was in fact low in those areas. In Gifu, a declining trend was observed in some remote watersheds, where there was no clear relationship between the geology and the long-term trends. Since Niigata and Gifu receive the highest level of acid loading from the atmosphere in Japan, river water acidification in several watersheds may be attributable to the effects of the acid deposition. Other factors, such as hot spring drainage, changes in land use, and natural sea salt deposition, cannot adequately explain the acidification phenomena observed in this study.

To evaluate the phytoremediation capability of some poplar and willow clones a hydroponic screening for cadmium tolerance, accumulation and translocation was performed. Rooted cuttings were exposed for 3 weeks to 50 μM cadmium sulphate in a growth chamber and morpho-physiological parameters and cadmium content distribution in various parts of the plant were evaluated. Total leaf area and root characteristics in clones and species were affected by cadmium treatment in different ways. Poplar clones showed a remarkable variability whereas willow clones were observed to be more homogeneous in cadmium accumulation and distribution. This behaviour was further confirmed by the calculation of the bio-concentration factor (BCF) and the translocation factor (Tf). Mean values of all the clones of the two Salicaceae species showed that willows had a far greater ability to tolerate cadmium than poplars, as indicated by the tolerance index (Ti), calculated on the dry weight of roots and shoots of plants. As far as the mean values of Tf was concerned, the capacity of willows to translocate was double that of poplars. On the contrary, the mean values of total BCF in poplar clones was far higher with respect to those in willows. The implications of these results in the selection of Salicaceae clones for phytoremediation purposes were discussed.

An investigation of radioactivity and some heavy metal distribution in soil and sediment of the river basin (Bendimahi River, Van-Turkey) was conducted in two seasons of 2005. The samples of soil and sediment were collected from the basin and investigated for concentrations of some heavy metal and natural radioactivity. Concentrations of Pb, Cr, Mn, Fe, Co, Cu, Zn and Cd have been determined by Atomic Absorption Spectrometry (AAS), gross-alpha and gross-beta activity concentrations have been obtained by using gas-flow proportional counter in nuclear spectroscopic system. Correlation analysis was made for radioactivity and heavy metal concentrations and the Pearson correlation coefficients between gross-alpha and gross-beta radioactivity and heavy metal were determined.

This study was conducted to evaluate the environmental fate processes of the herbicide (4-chloro-2-methylphenoxy)acetic acid (MCPA) in agricultural soils in the presence and absence of ash originating from the burning of wheat residue. The ash-amended soils (1% ash by weight) were approximately 8-16 times more effective than the ash-free soils in sorbing MCPA. The desorption results showed that 40-78% of initially sorbed MCPA were desorbed in both soils, depending on the initial MCPA concentration in solution. Addition of ash to soils decreased the desorption of MCPA by approximately 20%. Degradation of MCPA was substantially reduced in the presence of the ash. A 6-week incubation resulted in 50-85% of MCPA microbially degraded in ash-amended soils, as compared to >85-100% in ash-free soils under the same conditions.

As part of the Rain In Cumulus over the Ocean Experiment (RICO) and the Puerto Rico Aerosol and Cloud Study (PRACS), cloud water was collected at East Peak (EP) in Puerto Rico. The main objective of this study was to determine the concentrations of water-soluble species (Cl⁻, NO₃ ⁻, SO₄ ²⁻, NH₄ ⁺, Ca²⁺, H⁺, Mg²⁺, K⁺, and Na⁺) in water samples taken from clouds influenced by tropical trade winds. The most abundant inorganic species were Na⁺ (average 465 μeq l⁻¹) and Cl⁻ (434 μeq l⁻¹), followed by Mg²⁺ (105 μeq l⁻¹), SO₄ ²⁻ (61 μeq l⁻¹), and NO₃ ⁻ (25 μeq l⁻¹). High concentrations of nss-SO₄ ² (28 μeq l⁻¹), NO₃ ⁻ (86 μeq l⁻¹), and H⁺ (14.5 μeq l⁻¹) were measured with a shift in air masses origin from the North Atlantic to North American continent, which reflected a strong anthropogenic influence on cloud chemistry at EP. Long-range transport of particles and acid gases seems to be the factor responsible for fluctuations in concentrations and pH of cloud water at East Peak. When under trade wind influences the liquid phase concentrations of all inorganic substances were similar to those found in clouds in other clean maritime environments.

The delafossite CuCrO₂ is a promising candidate for the visible light driven catalysis. The NO₂ ⁻ removal by photoelectrochemical process is studied under mild conditions, close to that encountered in the natural environment. CuCrO₂ exhibits a long term chemical stability with a corrosion rate of 0.34 μmol m⁻² year⁻¹ in KCl (0.5 M). A forbidden band of 1.3 eV has been evaluated from the diffuse reflectance spectrum. The flat band potential (-0.07 V SCE) determined from the Mott-Schottky plot is close to the photocurrent onset potential (0 V SCE). Hence, the conduction band is positioned at -1.08 V SCE and thus lies below the NO₂ ⁻ level leading to a feasible reduction upon visible illumination. The conversion occurs in less than ~5 h with a quantum efficiency of ~0.5%. The possibility of identifying the reaction products via the intensity-potential characteristics was explored by using standard solutions. The decrease of the conversion rate over time is attributed to the competitive water reduction. In absence of catalyst, NO₂ ⁻ is oxidized to NO₃ ⁻ in air equilibrated solution and the reaction follows a first order kinetic with a half life of 21 h, NO₃ ⁻ has been identified by iodometry through copper titration.

The adsorption of Cu(II) ions by sodium-hydroxide-treated Imperata cylindrica (SoHIC) leaf powder was investigated under batch mode. The influence of solution pH, adsorbent dosage, shaking rate, copper concentration, contact time, and temperature was studied. Copper adsorption was considered fast as the time to reach equilibrium was 40-90 min. Several kinetic models were applied and it was found that pseudo-second-order fitted well the adsorption data. In order to understand the mechanism of adsorption, spectroscopic analyses involving scanning electron microscope (SEM) coupled with energy-dispersive spectroscopy (EDS) and Fourier transform infrared (FTIR) spectrophotometer were carried out. Ion exchange was proven the main mechanism involved as indicated by EDS spectra and as there was a release of light metal ions (K⁺, Na⁺, Mg²⁺, and Ca²⁺) during copper adsorption. Complexation also occurred as demonstrated by FTIR spectra involving hydroxyl, carboxylate, phosphate, ether, and amino functional groups. The equilibrium data were correlated with Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. Based on Langmuir model, the maximum adsorption capacity was recorded at the highest temperature of 310 K, which was 11.64 mg g⁻¹.

In this work, the potential removal of Cd, Cu, and Zn ions by non-living macrophytes Egeria densa has been studied. The adsorption kinetic and equilibrium experiments of these three metals on E. densa were performed in batch systems with controlled temperature and constant shaking. It was observed that all metal adsorption rates have increased when the pH was increasing. A pH threshold of 5 was established for use in adsorption experiments in order to avoid the metal precipitation. For adsorption kinetic tests, the equilibrium times for all metals were around 45 to 60 min. The equilibrium data at pH 5 were better described by the Langmuir isotherm than the Freundlich one, with the adsorption rate and maximum metal content values of 0.43 L g⁻¹ and 1.25 mequiv g⁻¹ for Cd, 4.11 L g⁻⁻¹ and 1.43 mequiv g⁻¹ for Cu, and 0.83 L g⁻¹ and 0.93 mequiv g⁻¹ for Zn. These adsorption parameters for E. densa resemble or are better than those for other biosorbents already studied, suggesting that the macrophytes E. densa as a biosorbent has a good metal removal potential for applications in effluent treatment systems.

For upper-division undergraduate or beginning graduate courses in civil and environmental engineering, this text has been revised and modernised to meet the needs of today's environmental engineering students who will be engaged in the design and management of water and wastewater systems.

Inkjet printing of metal nanoparticles is an attractive method for front-side metallization of silicon solar cells. It is owing to noncontact, low-cost, low-waste, and simple process. In this work, we proposed the ink-jet printing and electroless technology to fabricate the seed layer and electrode layer, respectively. Furthermore, we used electroplating method to increase the electrode conductivity. In this way, the energy conversion efficiency up to 12.22% without AR coating can be obtained on 100 × 100 mm c-Si cell.