In recent years, human pharmaceutical substances have been increasingly detected in the aquatic environment. Specific attention has been drawn to the occurrence of pharmaceutical substances at bank filtration sites which are used for drinking water production. In the course of the authorisation application for new pharmaceutical compounds, an environmental risk assessment is required. Currently, the expected concentration of the human pharmaceutical compound in groundwater at bank filtration sites is calculated following the guideline Pre-Authorisation Evaluation of Medicines for Human Use issued by the European Medicines Agency (EMEA 2006). A simple estimation is applied: The predicted environmental concentration (PECGW) is the predicted environmental concentration in surface water (PECSW) multiplied with 0.25. A new approach considering the hydraulic and hydrogeological characteristics of bank filtration sites as well as transport processes is presented in this study. First, a numerical groundwater flow model was developed to simulate the groundwater flow processes at bank filtration sites in general. Flow times were calculated as a function of the hydraulic and hydrogeological parameters: hydraulic conductivity, shore-well distance, screen depth and extraction rate. In a second step, the PECGW was calculated based on the compound concentration in surface water and the modelled groundwater flow times considering linear sorption and first-order decay. Sorption and degradation can only be calculated based on the data provided by the pharmaceutical company in the course of the authorisation application. The current approach following the EMEA guideline invariably connects the PECGW with the PECSW without considering sorption and/or degradation processes. We introduce an approach that incorporates the hydraulic process bank filtration and the main transport processes sorption and degradation. The new approach is compound specific as well as aquifer, flow and transport specific resulting in a more realistic PECGW value compared to the old approach.

Retardation of tritium migration in the Chinese loess media was studied through column experiments by comparison of the migration velocity with other three “non-adsorptive” tracers of Br−, 99Tc, and 131I. Results showed that the transport peak of Br− was 1.25 times earlier than that of tritium when the tracers were simultaneously injected into the column, and the migration of 99Tc was even 1.60 times faster than 3H when the tracers were simultaneously injected. For iodine, it was only 1.02 times faster than that of tritium, but it should not be ignored. It reflected that the transport of 3H, compared to that of Br−, 99Tc, or 131I in the loess media, was retarded. In order to validate the adsorption behavior of tritium on loess, batch tests were carried out using Chinese loess soil. The experimental results indicated that the adsorption of tritium was actual existence, and the distribution coefficient of tritium is influenced by initial activity of tritium, pH, water/solid ratio, and the content of humic and fulvic acids.

A major input in intensive organic agriculture is nutrient-rich liquid fertilizers. Guano and other fowl manure are frequently digested in water extracts, and the supernatant is supplied as fertilizer. The resultant manure biowaste (MBW) is commonly disposed of to the environment, posing potential pollution and health risks. The study aims were to determine two types of fowl MBWs for their chemical properties before and after lime treatment and to test their reuse potential as soil amendment. Guano and layer manure were digested, and the residues’ chemical properties were analyzed before and after lime treatment. MBWs were then air-dried and used as a soil amendment in a parsley-growing experiment. The lime-treated MBW composition met the European standards for high-quality biowaste compost. Both digested and lime-treated MBWs had residual nitrogen, 3% and 1% in guano and layer manure, respectively. Parsley grown in soil amended with layer MBW had 100% survival, high yield, and good crop quality compared with controls. Plants grown with soil amended with guano biowaste exhibited lower yield and only 50% survival. These findings indicate that the current practice of disposing guano biowaste to the environment may pollute soil and water bodies, while the land spread of lime-treated layer MBW is safe and may improve soil fertility.

This paper explores the regulation of water quality protection downstream from the Ranger Uranium Project in the Alligator Rivers Region, an area of high conservation value which is both World Heritage- and Ramsar-listed. Available historical monitoring data for surface water quality in Magela Creek downstream of Ranger have been compiled and analysed with respect to hydrologic data and the Australian and New Zealand Environment and Conservation Council–Agricultural and Resource Management Council of Australia and New Zealand (ANZECC–ARMCANZ) regulatory guidelines, introduced in late 2000. The paper focuses on the underlying scientific basis for the current approach and examines the complex inter-relationships of minesite water management, hydrology, climate, monitoring design, implementation and interpretation which are used to differentiate between natural variability and potential mine-derived solutes. The research found that the application of the ANZECC–ARMCANZ guidelines has clearly improved the regulation of water quality protection downstream from the Ranger Uranium Project. The scientific basis is more coherent than the previous regulatory regime; however, for U (a key parameter of indigenous Mirarr-Gundjeihmi and public concern), higher downstream concentrations are permitted than those observed through natural variability, leaving open the potential for an influence of mine-derived U loads while still being within regulatory limits. Another improvement that could be made to the current regulatory regime, to provide enhanced protection of the water quality in Magela Creek downstream of Ranger, would be to explicitly link the water quality monitoring regime with hydrologic flow conditions. The paper makes a valuable case study for the application of water quality guidelines, especially for controversial projects such as uranium mining surrounded by a World Heritage- and Ramsar-listed region on indigenous land—a context of clear relevance for many places around the world.

The use of multiwall carbon nanotubes (MWCNT) as an efficient solid extractor in preconcentration/cleanup studies for tin determination in water samples by electrothermal atomic absorption spectrometry (ETAAS) is proposed. In the proposed method, tin adsorption onto MWCNT was carried out by percolating the solution previously buffered (pH 4.79 with 0.24 mol L−1 acetic acid/acetate buffer) at 4.0-mL min−1 flow rate, followed by elution with 1.0 mL of 2.7 mol L−1 HNO3. Factors such as sample pH, preconcentration/cleanup flow rate, type and concentration of eluent, and buffer concentration were appraised and optimized from chemometric tools based on fractional factorial design and Doehlert design. A limit of detection of 0.73 μg L−1 and precision (n = 8) assessed as relative standard deviation of 8.6% and 7.0% for tin concentration of 8.0 and 43.0 μg L−1, respectively, were achieved. Foreign metallic ions (Ni2+, Pb2+, Co2+, Zn2+, Cd2+, Mn2+, and Fe3+) were checked as potential interferents, and no interference was observed up to an analyte/interference ratio of 1:10 (m/v). Direct tin determination by ETAAS in water samples containing high salt amount is drastically affected by background signal. However, previous cleanup of sample by MWCNT has promoted a significant improvement and makes the method useful for tin monitoring in water samples (mineral, lake, mine, and natural waters) by ETAAS. Quantitative recovery values ranging from 91.5% to 103.0% attested the applicability of the proposed preconcentration/cleanup for tin determination in water samples.

The objective of this research was the evaluation of the effects of exogenous added surfactants on hydrocarbon biodegradation and on cell surface properties. Crude oil hydrocarbons are often difficult to remove from the environment because of their insolubility in water. The addition of surfactants enhances the removal of hydrocarbons by raising the solubility of these compounds. These surfactants cause them to become more vulnerable to degradation, thereby facilitating transportation across the cell membrane. The obtained results showed that the microorganism consortia of bacteria are useful biological agents within environmental bioremediation. The most effective amongst all, as regards biodegradation, were the consortia of Pseudomonas spp. and Bacillus spp. strains. The results indicated that the natural surfactants (rhamnolipides and saponins) are more effective surfactants in hydrocarbon biodegradation as compared to Triton X-100. The addition of natural surfactants enhanced the removal of hydrocarbon and diesel oil from the environment. Very promising was the use of saponins as a surfactant in hydrocarbon biodegradation. This surfactant significantly increases the organic compound biodegradation. In the case of those surfactants that could be easily adsorbed on cells of strains (e.g., rhamnolipides), a change of hydrophobicity to ca. 30-40% was noted. As the final result, an increase in hydrocarbon biodegradation was observed.

Mechanism of zinc iron removal by zero-valent iron was discussed through zinc removal responses to several operational conditions of a packed column reactor with zero-valent iron powder. The adsorption isotherm observed implied that a kind of chemisorption was responsible for zinc removal. Zinc removal by zero-valent iron was enhanced by dissolved oxygen and ferric ion addition. However, it was deteriorated under acidic pH. In addition, zinc adsorbed on zero-valent iron was eluted by a reducing agent such as citric acid, whereas the zinc was not eluted by diluted sulfuric acid. Consequently, the zinc removal mechanism by zero-valent iron was inferred to be as follows: Zero-valent iron was firstly corroded and oxidized into ferric ion by dissolved oxygen. The ferric ion was precipitated as iron hydroxide onto the surface of the zero-valent iron powder. Zinc ion was adsorbed on and/or coprecipitated with the iron hydroxide. The iron hydroxide was finally oxidized and transformed into iron oxides.

In this study, Gonium sp. was investigated for possible usage in dye-containing wastewater treatment. Trials were performed in media including triacontanol hormone, Reactive Orange 14, Reactive Red 120, Reactive Black 5, Remazol Brilliant Blue R (RBBR), and also hormone against the controls. Algae could remove RBBR with the highest dye removal percentage (56%) among the tested dyes. The optimum pH was 9 in removing 50 mg L−1 RBBR at a dye removal percentage of 47.1%. The role of laccase activity of Gonium sp. was also investigated. This first attempt in the literature showed the involvement of the enzyme in the algal growth and bioremoval process. In the presence of the plant growth hormone in the culture, the activity showed a steady and significant increase up to nearly sixfold between 5th and 14th days of incubation.

In the last 20 years, a new generation of materials was developed: the biodegradable plastics. They reduce the accumulation of plastic in the environment and the cost of waste management because they can be fed in composting plants or, if used in agriculture (mulch films), they are applied to the soil and left there. Ten monomers were chosen among the most used in the synthesis of biodegradable polymers (1,2-ethanediol, 1,4-butanediol, 1,6-hexanediol, adipic acid, azelaic acid, sebacic acid, terephthalic acid, glucose, lactic acid, and succinic acid) and tested according to ASTM 5988-96 (a standard test method for determining aerobic biodegradation in soil of plastic materials measuring the carbon dioxide evolution). Two sandy loam soils, collected in two different sites in Italy, were used to evaluate the mineralization rate of the monomers. Four tests (two replicates each) were carried out for 27–39 days. Experimental data show no relevant differences in the respirations of the two soils and in the carbon dioxide productions of the tested monomers. The final mineralization percent was 42–45% for glucose, succinic, and lactic acid and 50–56% for the other monomers.

Modeling reactive transport with chemical equilibrium reactions requires solution of coupled partial differential and algebraic equations. In this work, two formulations are developed to combine the method of lines (MOL) with the global implicit approach. The first formulation has a non-conservative form and leads to a nonlinear system of ordinary differential equations with a reduced number of unknowns. The second formulation presents better conservation properties but leads to a nonlinear system of differential algebraic equations with a large number of unknowns. In both formulations, the resulting systems are integrated in time using the DLSODIS time solver which adapts both the order of the time integration and the time step size to provide the necessary accuracy. Numerical experiments show that higher-order time integration is effective for solving the non-conservative formulation and point out the high benefit of the MOL for solving reactive transport problems.