The effects of application of biosolids, at four rates, to an alkaline (pH 8.4), neutral (pH 7.0) and acidic (pH 4.0) soil on concentrations of Cu, Zn, Pb, Cd and dissolved organic C in soil solution were measured over a 170-day period in a laboratory incubation study using Rhizon pore water samplers. Applications of biosolids decreased solution pH in the alkaline soil, increased it in the acidic soil and had little effect in the neutral soil. In general, increasing application rates of biosolids progressively increased EC and concentrations of dissolved organic C (DOC), Cu, Zn, and to a lesser extent Cd and Pb, in soil solution. Concentrations of DOC and concentrations of solution Cu, Zn, and to a lesser extent solution Cd and Pb, decreased over the incubation period. In all three soils, concentrations of solution Cu and Zn were closely positively correlated with DOC concentrations and similar positive but weaker correlations were found for solution Cd and Pb. For the alkaline and neutral soils, concentrations of solution Cu, Zn, Cd and Pb were generally negatively correlated with solution pH but for the acidic soil, positive correlations for Cu and Zn were recorded. The percentage reduction in solution Cu and Zn, between 0 and 170 days incubation, increased with increasing rates of biosolids in the acid soil (where biosolids applications increased pH) but the reverse was the case for the alkaline soil (where pH fell following biosolids applications). Greatest percentage reduction in soluble Cu and Zn occurred in the neutral soil which had the greatest BET surface area, clay and organic matter contents and therefore the greatest capacity to adsorb heavy metal cations. It was concluded that solution pH, dissolved organic C and the intrinsic capacity of the soil to remove metals from solution, were the main factors interacting to regulate heavy metal cation solubility in the biosolids-amended soils.

A multiphase model based on the Mackay-type level II fugacity model has been used to predict the behaviour and final environmental concentrations of some of the more consumed pharmaceuticals in Spain. The model takes into account the mean rate of consumption of pharmaceuticals, the percentage of pharmaceutical metabolised, the formation of the corresponding glucuronide, which is assumed to be hydrolysed back to the parent molecule, the partial degradation of each pharmaceutical in a conventional sewage treatment plant, and the fate of these substances in a regional model environmental system. Predicted environmental concentrations in air, water, soil, sediments and suspended matter, and the corresponding residence time for each pharmaceutical have been obtained by application of the model. The predicted concentrations of pharmaceuticals in the water phase are of the same order than the measured experimentally, showing that the simple model used to predict the environmental concentrations is suitable for modelling the environmental fate of high water soluble and low volatile organic compounds such as pharmaceuticals products.

Typical controlled drainage structures in drainage ditches provide drainage management strategies for isolated temporal periods. Innovative, low-grade weirs are anticipated to provide hydraulic control on an annual basis, as well as be installed at multiple sites within the drainage ditch for improved spatial biogeochemical transformations. This study provides evidence toward the capacity of low-grade weirs for nutrient reductions, when compared to the typical controlled drainage structure of a slotted riser treatment. Three ditches with weirs were compared against three ditches with slotted risers, and two control ditches for hydraulic residence time (HRT) and nutrient reductions. There were no differences in water volume or HRT between weired and riser systems. Nutrient concentrations significantly decreased from inflow to outflow in both controlled drainage strategies, but there were few statistical differences in N and P concentration reductions between controlled drainage treatments. Similarly, there were significant declines in N and P loads, but no statistical differences in median N and P outflow loads between weir (W) and riser (R) ditches for dissolved inorganic phosphate (W, 92%; R, 94%), total inorganic phosphate (W, 86%; R, 88%), nitrate-N (W, 98%; R, 96%), and ammonium (W, 67%; R, 85%) when nutrients were introduced as runoff events. These results indicate the importance of HRT in improving nutrient reductions. Low-grade weirs should operate as important drainage control structures in reducing nutrient loads to downstream receiving systems if the hydraulic residence time of the system is significantly increased with multiple weirs, as a result of ditch length and slope.

Identifying the factors responsible for the diversity of responses of biota to industrial pollution is crucial for predicting the fates of polluted ecosystems. A meta-analysis based on 49 field studies conducted around 47 point polluters demonstrated that the individual (growth and reproduction) and community (abundance and species richness) characteristics of bryophytes in polluted habitats are reduced to about a half of the values observed in unpolluted sites. Non-ferrous smelters cause a stronger reduction in species richness and larger changes in species composition than other types of polluters. The magnitudes of the effects of pollution on the abundances of individual bryophyte species are not linked with their taxonomic position, life form or Ellenberg indicator values for light, moisture and nitrogen. The variation in species’ responses to pollution is mostly explained by differences in their reproductive characteristics; bryophyte species that possess special forms of vegetative reproduction and those that produce abundant sporophytes are more successful in polluted habitats. Ranking of bryophyte species according to their sensitivity to pollution is independent of the type of the polluter. Changes in bryophyte cover follow changes in tree cover, but not changes in the cover of the vascular field layer in the same pollution gradients. Pollution impacts cause stronger adverse effects on bryophytes in warmer climates.

The toxicities of three synthetic surfactants to the marine macroalga, Ulva lactuca, have been examined by monitoring chlorophyll a fluorescence quenching. The anionic surfactant, sodium dodecyl sulphate (SDS), exerted no measurable toxicity over the concentration range 0–10 mg L−1, while presence of the non-ionic surfactant, Triton X-100 (TX), elicited a small reduction in photochemical efficiency that was independent of concentration. The cationic surfactant, hexadecyltrimethylammonium bromide (HDTMA), incurred a dose-dependent response to ∼3 mg L−1 (EC50 = 2.4 mg L−1), but a reduction in toxicity thereafter. Presence of TX had little effect on the toxicity of HDTMA but an equimolar concentration of SDS directly offset the impact of HDTMA on photochemical efficiency. Relative toxicities of the surfactants are attributed to differences in affinity for the algal surface and tendencies to disrupt cell membranes and interact with intracellular macromolecules. Non-linear dose responses and antagonistic effects are attributed to non-specific interactions between molecules of the same surfactant and electrostatic interactions between molecules of different amphiphilic character.

Limnologists have regarded temporal coherence (synchrony) as a powerful tool for identifying the relative importance of local-scale regulators and regional climatic drivers on lake ecosystems. Limnological studies on Asian reservoirs have emphasized that climate and hydrology under the influences of monsoon are dominant factors regulating seasonal patterns of lake trophic status; yet, little is known of synchrony or asynchrony of trophic status in the single reservoir ecosystem. Based on monthly monitoring data of chlorophyll a, transparency, nutrients, and nonvolatile suspended solids (NVSS) during 1-year period, the present study evaluated temporal coherence to test whether local-scale regulators disturb the seasonal dynamics of trophic state indices (TSI) in a giant dendritic reservoir, China (Three Gorges Reservoir, TGR). Reservoir-wide coherences for TSICHL, TSISD, and TSITP showed dramatic variations over spatial scale, indicating temporal asynchrony of trophic status. Following the concept of TSI differences, algal productivity in the mainstream of TGR and Xiangxi Bay except the upstream of the bay were always limited by nonalgal turbidity (TSICHL−TSISD <0) rather than nitrogen and phosphorus (TSICHL−TSITN <0 and TSICHL−TSITP <0). The coherence analysis for TSI differences showed that local processes of Xiangxi Bay were the main responsible for local asynchrony of nonalgal turbidity limitation levels. Regression analysis further proved that local temporal asynchrony for TSISD and nonalgal turbidity limitation levels were regulated by local dynamics of NVSS, rather than geographical distance. The implications of the present study are to emphasize that the results of trophic status obtained from a single environment (reservoir mainstream) cannot be extrapolated to other environments (tributary bay) in a way that would allow its use as a sentinel site.

Polymeric quaternary ammonium salts or polyquaterniums used in cosmetics have been categorised as chemicals of concern in wastewater treatment plant (WWTP) effluent largely on the basis of emerging evidence of toxicity to aquatic organisms. However, little is known of their environmental fate and behaviour due to analytical difficulties with sample matrices. Their properties of negligible volatilisation and biotransformation enable the common fugacity-based model for WWTPs to be simplified to an equifugacity one where a compound has the same fugacity regardless of phase or position in the plant’s process train. To gain an appreciation of their fate, this approach is used to calculate removal efficiencies in WWTPs. These can be determined without calculating phase-specific fugacity capacity constants. To predict effluent concentrations however, an aquivalence approach is necessary because of the lack of volatility of these compounds. Using previously measured biosolids/water distribution coefficients for common polyquaterniums found in cosmetics and flow rate data from a local municipal WWTP in South East Queensland, Australia, the removal efficiencies of the polyquaterniums of interest are predicted to be only 25% or less, meaning relatively little attenuation in the WWTP. A Monte Carlo simulation shows a roughly normal distribution in the model output of polyquaternium removal efficiency, with a mean and mode of approximately 26%. A sensitivity analysis confirms that the model output is most sensitive to the magnitude of the biosolids/water distribution coefficient compound and shows WWTP data such as biosolids removal efficiency have only a relatively small effect.

Excitation–emission matrix fluorescence spectroscopy, combined with parallel factor analysis and measurements of UV absorption and dissolved organic carbon (DOC) concentrations, was used to trace the footprints of industrial effluents discharged into the lower Kishon River (Israel). The lower Kishon River typifies streams that are affected by seawater tidal intrusion and represents an extreme case of severe long-term pollution caused mainly by a variety of industrial effluents. The industrial effluents may contribute about 90%, in terms of biochemical oxygen demand, of the total organic carbon discharged into the lower Kishon River. Water samples were collected along the river, including the points of effluent discharge from industrial plants, between November 2005 and September 2006. Two types of fluorescent components characterized the fluorescence of the lower Kishon River water: component I corresponded to humic-like matter and component II spectrally resembled material known to be associated with biological productivity, but different from typical tryptophan-like fluorophore. These fluorescent components and other substances that absorbed light at 254 nm contributed to the DOC pool that resisted riverine microbial degradation under laboratory conditions, and that constitutes up to 70% of the overall riverine DOC. The variations in DOC concentration, absorbance at 254 nm, and concentration of humic-like matter (characterized by component I) correlated with the distance from the sea and the water electrical conductivity, and were linked to seawater tidal intrusion. The increased concentration of component II, as well as its enlarged fraction in the overall riverine DOC pool, was found to be associated with the location of major inputs of the industrial effluents. These findings support the use of this fluorescent component as an indicator of industrial pollution in such severely contaminated riverine systems.

Phosphorus losses in runoff from sugarcane fields can contribute to non-point source pollution of surface and subsurface waters. The objective of this study was to evaluate the effects of three different management practices on P losses in surface runoff and subsurface leaching from sugarcane (Saccharum officinarum L.) fields. Field experiments with treatments including conventional burning (CB), compost application with burning (COMB), and remaining green cane trash blanketing (GCTB) treatments were carried out to assess these management practice effects on P losses from sugarcane fields. In the CB treatment, sugarcane residue was burned after harvest. The COMB treatment consisted of compost applied at “off bar” with sugarcane residue burned immediately after harvest. Compost was applied in the amount of 13.4 Mg ha−1 annually, 8 weeks before planting. In the GCTB treatment, sugarcane residue was raked off from the row tops and remained in the wheel furrow after harvest. Surface runoff was collected with automatic refrigerated samplers, and subsurface leachate was collected with pan lysimeters over a period of 3 years. Measured concentrations of total P (TP), dissolved reactive P (DRP), and particulate P (PP) in surface runoff from the COMB treatment were significantly higher than concentrations from the CB and GCTB treatments. The mean losses of P (TP and DRP) after burning (postharvest, years 2 and 3) were significantly greater than the no-burn treatment (preharvest, year 1) in the CB, COMB, and CB/COMB/GCTB combined options. Additionally, the mean losses of total suspended solid and total combustible solids in residue burning were, on average, 2.7 and 2.2 times higher than the no-burn practices, respectively (preharvest and GCTB treatment). Annual P losses from surface runoff in the third year of study were 12.90%, 6.86%, and 10.23% of applied P in CB, COMB, and GCTB treatments, respectively. However, the percent of annual DRP losses from applied P in COMB and GCTB treatments was similar magnitude, and their values were less than 50% compared to the value from CB treatment. In the leaching study, percent of monthly mean TP and DRP losses in the COMB and GCTB treatments were greatly reduced. Based on these results, the COMB and GCTB procedures were equally recommended as sugarcane management practices that improve water quality in both surface runoff and subsurface leachate.

The present paper aims at planning the treated municipal wastewater reuse in fragile ecosystems of Messolonghion lagoon and Acheloos estuary, which are protected as a Natura wetland under the Ramsar Treaty. The need for environmental protection of the wetlands became necessary due to the continuing anthropogenic intervention, as well as to the climate changes that have been occurring in recent years. Relevant studies have shown that the lagoon of Messolonghion and Acheloos estuary are ecosystems that have been burdened by anthropogenic activities (pesticides, fertilizers, overexploitation of underground aquifers, intrusion and land use change), as well as by climatic changes (temperature, precipitation, sea level), which altogether have adversely affected the hydrodynamic and ecological balance of the entire ecosystem. The Messolonghion lagoon and Acheloos estuary are also the recipients of the wastewater processing plant effluents, operating locally, which have over-enriched the waters with macronutrients N, P and K, favouring eutrophication. The municipal wastewater reuse for crop irrigation grown in the protected area appears to be an environmentally acceptable solution for alleviating the natural water shortage, since it could save significant amounts of irrigation water as well as it could reduce the adverse effects of the treated effluents discharge into the aquatic ecosystem. This study describes the planning of the treated wastewater reuse in this ecologically sensitive area, on the basis of the geomorphologic and geotechnical characteristics, climatic factors, and crop irrigation water requirements grown in the area.