Agricultural reuse of treated sewage effluent (TSE) is an environmental and economic practice; however, little is known about its effects on the characteristics and microbial function in tropical soils. The effect of surplus irrigation of a pasture with TSE, in a period of 18 months, was investigated, considering the effect of 0% surplus irrigation with TSE as a control. In addition, the experiment consisted of three surplus treatments (25%, 50%, and 100% excess) and a nonirrigated pasture area (SE) to compare the soil microbial community level physiological profiles, using the Biolog method. The TSE application increased the average substrate consumption of the soil microbial community, based on the kinetic parameters of the average well color development curve fitting. There were no significant differences between the levels of surplus irrigation treatments. Surplus TSE pasture irrigation caused minor increases in the physiological status of the soil microbial community but no detectable damage to the pasture or soil.

Analytical procedures for the determination of pharmaceuticals from different therapeutic groups were proposed. These groups included the corticosteroids prednisolone and dexamethasone; the β-blockers sotalol, metoprolol, propranolol, and carvedilol; and the analgesic nonsteroidal anti-inflammatory drugs paracetamol, aspirin, metamizole, and ketoprofen. Reversed-phase ultrahigh performance liquid chromatography with an ultraviolet detector, different columns, different mobile phases, and gradient elution programmes were used to obtain the best separations within the shortest possible time. Solid-phase extraction was examined as a preconcentration step. The Oasis HLB column, with the highest recoveries (over 90% for most of the drugs), was chosen for the analysis of surface waters. Limits of detection ranged from 0.06 to 0.39 μg L⁻¹ for all drugs after optimisation of all analytical steps.

Reductive dechlorination of tetrachloroethylene (PCE) by green rust modified with copper (GR(Cu)) was investigated using a batch reactor system. Four different forms of GRs (GR-Cl, GR-SO₄, GR-CO₃, and GR-F) were synthesized by partial air oxidation of Fe(OH)₂ and used in reductive dechlorination. The addition of Cu(II) into GRs produced 100-nm particles on the surface of GRs, which were considered to be metallic Cu and transformed a portion of GR to magnetite. Concentration of Fe(II) in the liquid phase increased and concentration of Fe(II) in the solid phase decreased during the modification process and the extent of these changes was dependent on the amount of Cu(II) added. The most reactive of the modified GRs was GR-F(Cu), which reacted with PCE at a rate that was 80 times faster than that of GR-Cl(Cu). The rate of PCE degradation by GR-F(Cu) was strongly dependent on pH with higher rates at higher pH over the range of pH 7.5-11. Increasing concentrations of Cu(II) over the range of 0 to 5 mM increased rate constants. The rate of dechlorination of PCE by GR-F(Cu) showed surface saturation behavior with respect to PCE concentration.

Diverting the infiltrating water away from the zone of N application can reduce nitrate-nitrogen (NO₃-N) leaching losses to groundwater from agricultural fields. This study was conducted from 2001 through 2005 to determine the effects of N-application methods using a localized compaction and doming (LCD) applicator and spoke injector on NO₃-N leaching losses to subsurface drainage water and corn (Zea mays L.)-soybean (Glycine max L.) yields. The field experiments were conducted at the Iowa State University's northeastern research center near Nashua, Iowa, on corn-soybean rotation plots under chisel plow system having subsurface drainage ‘tile' system installed in 1979. The soils at the site are glacial till derived soils. The N-application rates of 168 kg-N ha⁻¹ were applied to corn only for both the treatments each replicated three times in a randomized complete block design. For combined 5 years, the LCD N-applicator in comparison with spoke injector showed lower flow weighted NO₃-N concentrations in tile water (16.8 vs. 20.1 mg L⁻¹) from corn plots, greater tile flow (66 vs. 49 mm), almost equivalent NO₃-N leaching loss with tile water (11.5 vs. 11.3 kg-N ha⁻¹) and similar corn grain yields (11.17 vs. 11.37 Mg ha⁻¹), respectively, although treatments effects were found to be non-significant (p = 0.05) statistically. The analysis, however, revealed that amount and temporal distribution of the growing season precipitation also affected the tile flow, NO₃-N leaching loss to subsurface drain water, and corn-soybean yields. Moreover, the spatial variability effects from plot to plot in some cases, resulted in differences of tile flow and NO₃-N leaching losses in the range of three to four times despite being treated with the same management practices. These results indicate that the LCD N-applicator in comparison with spoke injector resulted in lower flow weighted NO₃-N concentrations in subsurface drain water of corn plots; however, strategies need to be developed to reduce the offsite transport of nitrate leaching losses during early spring period from March through June.

Polycyclic aromatic hydrocarbons (PAHs); their derivatives nitro, and methyl-PAHs; n-alkanes; and organic acids were investigated in the aerosol samples collected during two field campaigns conducted at three sampling stations in an industrialized city in southern Italy. The main sources affecting the atmosphere and its toxicity were investigated by means of the diagnostic ratios of: specific particulate-phase PAHs, marker compounds among nitro-PAHs, alkanes, and acids, the dominant wind direction, daily and seasonal abundance of carcinogenic organic substances. The potential importance of the non-regulated pollutants to assess the air quality was confirmed; in fact the carcinogenic organic compounds showed to have scarce correlation with particulate matter (PM) concentration. An exceptionally high variability of toxic compounds at a daily scale was due to meteorological condition causing periods of extremely high pollution levels.

There is evidence in the literature that the ratio of mass of sorbent (M) to volume of solution (V) affects the results of batch tests with soils and sediments. This restricts the use of such data to conditions with the same M/V ratio they were derived with, unless its influence is corrected. To find a correction, we conducted batch tests with soil and zinc solution using four M/V ratios. For each ratio, the experiments produced a different relationship between the mass of zinc sorbed per unit mass of soil (a s) and the zinc concentration in the solution after shaking and removal of the solid phase (C det), which is usually taken as the equilibrium concentration (C eq). A theoretical analysis revealed that the M/V effect can be accounted for by dividing C det by the M/V ratio, if it is caused by the presence of a “third phase”. The relationship between a s and C det×V/M is the same for all ratios then.

The current study investigated the sorption of sulfadimethoxine (SMT), sulfamethoxazole (SMX), tetracycline (TET), and oxytetracycline (OTC) to Na-rich montmorillonite clay in synthetic effluent (SE) and field wastewater effluent (FE). Both SMT and SMX showed a low sorption capacity and are therefore likely to be highly mobile in the environment, while the sorption of TET to clay in environmental pH range (6.5-7.5) showed similarly high adsorption capacity. Differences in sorption capacities of TET and OTC to SE or FE were attributed to the various concentrations of divalent cations in the effluents. In addition, differences in sorption of OTC or TET to SE were attributed to their different molecular structure. Moreover, the adsorption of TET in SE and FE showed linear adsorption isotherms and fitted to Freundlich model. Further experiments showed that addition of humic acid or SE to TET sorbed to clay did not enhance or suppress the sorption of TET to clay.

Thermogravimetry (TG) was used to investigate the pollution on marine sediments close to urban and industrial sites. Sediment weight loss when heated (TG) was performed under oxidizing conditions from 250°C to 900°C. The first derivative of TG curves was used to generate a Cartesian diagram for sediments cataloging, in a quick way, according to their organic matter and grain size contents. Thus, sediment placed at the right of the diagram were characterized by a prevalence of the thin fraction and high organic matter content, while on the left side, samples were characterized by large sandy fractions, and, in general, low organic matter contents. Two references materials and metal pollution index were used to validate the Cartesian diagram obtained.

In order to observe the spatial phosphorus (P) fractions transformations in sediments in relation to bacterial abundance and enzyme hydrolysing organic P-alkaline phosphatase (APA), samples from 35 stations from eutrophic Sulejow Reservoir were taken in spring after flood and in summer after cyanobacterial bloom breakdown. The results show pronounced fluctuations: decrease of average total P in sediments, despite organic matter delivery after cyanobacterial bloom, in parallel with increase of labile P (8.3%) and Ca-bounded P (16.6%) fractions and decline of organic P fraction (28.5%). Higher alkaline activity in sediments in the spring delivered nutrients to water column and supported cyanobacterial bloom development during the summer. Positive correlation between APA and organic P (r = 0.37, p < 0.01, n = 70) and negative with labile inorganic P (r = −0.44, p < 0.01, n = 70) in sediments proved significant role of the APA in phosphorus transformation in sediments and internal loading in the reservoir. During summer, APA was significantly related to bacterial number (r = 0.36, p < 0.01, n = 35) and bacterial abundance was correlated to organic matter content (r = 0.36, p < 0.01, n = 35). Such pattern of temporal variations of P transformation in sediments indicates order of solutions for enhancement of recultivation effects of eutrophic dam reservoirs: (1) reduction of organic matter supply in spring and (2) sediment inactivation during summer.

The effects of cadmium (Cd) and/or paraquat (PQ) toxicity on photosynthesis in maize leaves were examined by measurement of gas exchange and chlorophyll content in hydroponically cultured plants. It was found that growth rate was distinctly influenced only by 100 µM Cd treatment. Chlorophyll a and chlorophyll b decreased along with the increase of Cd concentration, while PQ spraying, alone and combined with Cd, increased chlorophyll a content on the third and seventh experimental days. Generally, carotenoid content increased in response to Cd and PQ and reached the highest levels at 100 µM Cd. Rate of photosynthesis in maize decreased after Cd treatment. CO₂ assimilation was approximately 60% reduced at 50 µM Cd and 70% reduced in the presence of 100 µM Cd. PQ toxicity was partly overcome after the third day of exposure. Transpiration and stomatal conductance in maize leaves decreased on the third day along with Cd concentration and PQ spraying, except for the 25-µM Cd-treated plants. On the tenth day, the 25-µM Cd-treated plants and those from PQ-treated variants showed an increase of transpiration and stomatal conductance. Maize exhibited an ability to accumulate Cd in high quantities, especially in the roots—over 4,500 mg Cd/kg dry weight.