Ecotoxicological evaluation of pig slurry

Long-Term Effect of Pig Slurry and Mineral Fertilizer Additions on Soil Nutrient Content, Field Pea Grain and Straw Yield under Winter Wheat–Spring Barley–Field Pea Crop Rotation on Cambisol and Luvisol

Different fertilizers have different effects on soil chemistry and crop yields. In this paper, we analyzed how long-term and regular application of mineral fertilizers, pig slurry and their combinations (15 fertilizer treatments totally) affect soil pH, nutrient content and yield of field pea at two sites with different soil (cambisol and luvisol) and climatic conditions. The long-term trials evaluated in this paper were established in 1972 at Pernolec and Kostelec, Czech Republic. Results of the soil analyses (evaluated period) are from the years 2015–2020, covering two sequences of crop rotation (winter wheat–spring barley–field pea). The fertilizer treatments significantly affected the soil reaction; application of mineral fertilizers and their combinations resulted in the lowest pH values. On the other hand, the same treatments provided the highest yields and left the highest pool of nutrients in the soil. Pig slurry can provide the same yields of field pea as mineral NPK fertilizers, without a negative effect on soil reaction. Analyzing the mineral fertilizers only, a reasonable dose of N (according to the linear-plateau model) can range from 73 and 97 kg ha−1 N in Pernolec, according to the weather conditions.

Assessment of phytotoxicity of leachates from landfilled waste and dust from foundry

The study assesses the contamination, classification and phytotoxicity of foundry waste. The presented results are a part of the research on the agrotechnical use of foundry waste. Landfilled foundry waste (LFW) and dust samples were taken from one of the Polish foundries. An analysis of the waste and its leachate composition was conducted. Phytotoxicity tests were carried out using Lepidium sativum. The aim of the phytotoxicity study was to evaluate germination and root growth after 72 h and the accumulation of heavy metals after 7 days. LFW was least contaminated with heavy metals and metalloids compared to dust. The composition of the foundry dusts depended on the unit of the foundry, from which it was collected. It was found that electric arc furnace dust (EAFD) was the most polluted by heavy metals among the dust samples. According to the requirements of Polish regulations most of tested waste were classified as non-hazardous, and EAFD as hazardous waste due to high Pb concentration in leachate. Phytotoxicity tests have shown a low phytotoxicity of the leachate from most of the tested waste. The results of the accumulation test showed that an excess of metal and metalloids in leachate was not directly related to its accumulation in plants. A negative correlation between EC, Cu, Co, Fe, Pb, Cr, K, Na, sulfate, fluoride, ammonia, phenol and formaldehyde concentration in leachate and GI was found. It was stated that the Fe, Mn, As and Se in plants was significantly correlated with concentrations in leachate.

Sulfide and arsenic compounds removal from liquid digestate by ferric coagulation and toxicity evaluation

The liquid digestate has been regarded as a potential organic fertilizer for its benefit in nutrients recovery. However, the potential risk of hazardous substances remaining in the wastewater was still one of the main obstacles for the wastewater application in the circular agriculture. The pretreatment is important to remove pollutants with relatively satisfied results. Ferric coagulation was a feasible way to simultaneously remove various contaminants in the wastewater with few residuals of ferric ions under alkaline and neutral conditions. In special, it could reduce the residues of sulfide and arsenic compounds. We gained insights into the mechanism of ferric coagulation in removing sulfide and arsenic compounds. Redox reaction and precipitation were the reasons resulting in removing sulfide. The formation of precipitate by combining with iron(III) contributes to the removal of arsenic compounds. Toxicity tests using Scenedesmus obliquus and Chlorella pyrenoidosa showed an obvious reduction of toxicity for the liquid digestate after ferric coagulation. Besides, ferric coagulation could efficiently remove turbidity, reduce COD, and eliminate dissolved organic matters correlated with the fate of heavy metal and antibiotics. Therefore, this paper could give basic data and technique supports for the secure utilization and pollution control of liquid digestate. PRACTITIONER POINTS: Most sulfide and arsenic compounds were removed by 0.01 M ferric coagulation. Mechanisms on removing hazardous substances by ferric coagulation were discussed based on analysis of X-ray photoelectron spectroscopy and FTIR. The evaluation by two algae showed the toxicity of liquid digestate could be reduced obviously after ferric coagulation.

Indole Degradation in a Model System and in Poultry Manure by Acinetobacter spp

Indole degradation in a model system and in poultry manure was studied using an enrichment culture of two Acinetobacter species; Acinetobacter toweneri NTA1-2A and Acinetobacter guillouiae TAT1-6A. Degradation of indole was quantified using reverse phase high performance liquid chromatography (HPLC). The two strains were capable of degrading initial concentrations of indole ranging from 58.58–300 mg/L. The degradation efficiency was 66.36% (NTA1-2A), 94.87% (TAT1-6A), and 96.00% (mix) in 6 days when the initial concentration <300 mg/L. The strains were tested for enzymatic activity using 120 mg/L indole. The enzyme extracts of NTA1-2A and TAT1-6A from culture medium degraded indole completely, and no appreciable change of indole concentration was witnessed in the control group. The NTA1-2A, TAT1-6A, and the mix of strains were also used for in vivo poultry manure fermentation and removed 78.67%, 83.28%, and 83.70% of indole, respectively in 8 d. The strains showed a statistically significant difference (p < 0.05) in indole removal efficiency compared with the control, but no significant difference between the two strains and the mix in indole removal capacity. We concluded that A. toweneri NTA1-2A and A. guillouiae TAT1-6A are promising strains to remove indole and its derivatives to control the notorious odor in poultry and other livestock industries.

Evaluation of the dynamics of microalgae population structure and process performance during piggery wastewater treatment in algal-bacterial photobioreactors

The dynamics of microalgae population during piggery wastewater (PWW) treatment in four open photobioreactors operated at 27days of hydraulic retention time, and inoculated with Chlorella sp. (R1), Acutodesmus obliquus (R2), Oscillatoria sp. (R3) and in the absence of inoculum (R4), were evaluated for 6months. In addition, the algal-bacterial biomass concentration, removal of organic matter, nutrients and heavy metals were also assessed. The results revealed a high diversity and rapid variations in the structure of microalgae populations, Chlorella sp. being dominant in R4 throughout most of the operational period. Steady state average biomass concentration ranged from 2445-2610mg/L in R1-R3 to 3265mg/L in R4. No significant differences were recorded in the removal efficiencies (REs) of total organic carbon (86-87%), inorganic carbon (62-71%), total nitrogen (82-85%) and total phosphorous (90-92%). Finally, Zn-REs accounted for 26% in R3, 37% in R2, and 49% in R1 and R4.

Properties of the filtrate from treatment of pig manure by filtration method

This paper presents properties of filtrate obtained from pig manure using the AMAK treatment process, which includes the mineralization of macro- and microfertilizer components by the hydrolyzing of organic matter into forms that are bioavailable to plants. Filtration produced two products, sediment and filtrate. The quality of the filtrate allowed for its use as a substitute of water to irrigate crops. Concentrations of heavy metals are very low and therefore the quality of the filtrate fully complies with European standard concerning fertilizers. The used mineralization process practically eliminated odors from the filtrate. The reduction of specific odor emission by 99.1-99.5% in samples taken from above the filtrate, respectively compared to the odor concentration found in samples taken from above raw pig manure. Sediment could be used as raw material for production of mineral-organic fertilizer. Filtrate and filtration sediments analyses show that the majority of nitrogen and other fertilizing compounds included in raw pig manure remains in sediment.

Sedimentary record and anthropogenic pollution of a complex, multiple source fed dam reservoirs: An example from the Nové Mlýny reservoir, Czech Republic

While numerous studies of dam reservoirs contamination are reported world-wide, we present a missing link in the study of reservoirs sourced from multiple river catchments. In such reservoirs, different point sources of contaminants and variable composition of their sedimentary matrices add to extremely complex geochemical patterns. We studied a unique, step-wise filled Nové Mlýny dam reservoir, Czech Republic, which consists of three interconnected sub-basins. Their source areas are located in units with contrasting geology and different levels and sources of contamination. The aim of this study is to provide an insight into the provenance of the sediment, including lithogenic elements and anthropogenic pollutants, to investigate the sediment dispersal across the reservoir, and to assess the heavy metal pollution in each basin. The study is based on multi-proxy stratigraphic analysis and geochemistry of sediment cores. There is a considerable gradient in the sediment grain size, brightness, MS and geochemistry, which reflects changing hydrodynamic energy conditions and primary pelagic production of CaCO₃. The thickness of sediments generally decreases from proximal to distal parts, but underwater currents can accumulate higher amounts of sediments in distal parts near the thalweg line. Average sedimentation rates vary over a wide range from 0.58cm/yr to 2.33cm/yr. In addition, the petrophysical patterns, concentrations of lithogenic elements and their ratios made it possible to identify two main provenance areas, the Dyje River catchment (upper basin) and the Svratka and Jihlava River catchments (middle and lower basin). Enrichment factors (EF) were used for distinguishing the anthropogenic element contribution from the local background levels. We found moderate Zn and Cu pollution (EF ~2 to 5) in the upper basin and Zn, Cu and Pb (EF ~2 to 4.5) in the middle basin with the peak contamination in the late 1980s, indicating that the two basins have different contamination histories.

Ecotoxicological effects of pig manure on Folsomia candida in subtropical Brazilian soils

The effects of pig manure, from diets incorporating veterinary pharmaceuticals, on survival and reproduction of Folsomia candida were evaluated. Manures derived from the following diets: corn and soymeal (CS); 85% CS diet+15% wheat meal (TR); CS diet+100ppm doxycycline+50ppm colistin+2500ppm Zn oxide (CSa); TR diet+100ppm doxycycline+50ppm colistin+2500ppm Zn oxide (TRa). Manures were tested in two subtropical soils representative of southern (Oxisol and Entisol). Despite the antibiotics no significant differences were found between the four manures within each soil. However, strong differences were found on the toxicity between soils. In Oxisol, LC50 values were around 100m(3)ha(-1), and EC50 values around 80m(3)ha(-1). In Entisol these were much lower, with LC50 values oscillating around 20m(3)ha(-1) and EC50 values between 10-15m(3)ha(-1). The observed toxicity on both soils was attributed to excess of nitrogen, Cu and Zn in the highest doses. The strong difference between soils could be explained by soil properties, namely CEC, organic matter, and clay contents that were lower in Entisol, indicating a poor ability to retain contaminants increasing their availability in soil. Results suggest that the application of these residues should be regulated not only using a volume-based criterion, but should incorporate data on soil properties, complemented by an ecotoxicological assessment.

Is digestate safe? A study on its ecotoxicity and environmental risk on a pig manure

Digestate represents a precious by-product in particular in agriculture, however its impact on the environment and human health is still unexplored. In this work, the toxicity of a pig slurry digestate was assessed through 7 ecotoxicity tests and considering 10 different endpoints. Besides, a synthetic index was applied to the outputs of the battery of tests for the environmental risk assessment, in order to evaluate the opportunity to use directly this kind of digestate in agriculture or to introduce an additional treatment. All the organisms were sensitive to digestate toxicity (EC50 ranged from 14.22% for Cucumissativus to 0.77% for Raphidocelis subcapitata). The physical-chemical features at the base of this toxicity seem to be the high content of ammonium, salinity, COD, phosphate and colour. The synthetic index showed that the digestate was very toxic and associated to an extremely high environmental risk. Thus, a pre-treatment is needed to reduce its toxicity and environmental impact, whatever could be its exploitation.

Ecotoxicological assessment of the potential impact on soil porewater, surface and groundwater from the use of organic wastes as soil amendments

This study aimed to assess the potential impact on soil porewater, surface and groundwater from the beneficial application of organic wastes to soil, using their eluates and acute bioassays with aquatic organisms and plants: luminescence inhibition of Vibrio fischeri (15 and 30 min), Daphnia magna immobilization (48 h), Thamnocephalus platyurus survival (24 h), and seed germination of Lolium perenne (7 d) and Lactuca sativa (5 d). Some organic wastes' eluates promoted high toxic responses, but that toxicity could not be predicted by their chemical characterization, which is compulsory by regulatory documents. In fact, when organisms were exposed to the water-extractable chemical compounds of the organic wastes, the toxic responses were more connected to the degree of stabilization of the organic wastes, or to the treatment used to achieve that stabilization, than to their contaminant load. That is why the environmental risk assessment of the use of organic wastes as soil amendments should integrate bioassays with eluates, in order to correctly evaluate the effects of the most bioavailable fraction of all the chemical compounds, which can be difficult to predict from the characterization required in regulatory documents. According to our results, some rapid and standardized acute bioassays can be suggested to integrate a Tier 1 ecotoxicological evaluation of organic wastes with potential to be land applied, namely luminescence inhibition of V. fischeri, D. magna immobilization, and the germination of L. perenne and L. sativa.

Effects of long term raw pig slurry inputs on nutrient and metal contamination of tropical volcanogenic soils, Uvéa Island (South Pacific)

In small Polynesian islands, family pig breeding is usually conducted without recovery of pig slurry. Raw pig slurry is spread onto the soil without any treatment. So far, most of the studies were carried out in temperate climate and for industrial digested pig slurry applications on agricultural lands. In the present case study, conducted in Uvéa Island, the aim is to determine if long term application of raw pig slurry on tropical soils, naturally rich in heavy metals has a significant influence on elements concentrations and mobility. Two types of tropical soils and two pig breeding systems, pig enclosure on small concrete pens or pig enclosure in large land pens, were investigated. Here we demonstrate that raw pig slurry inputs on soils can lead to an increase of total nitrogen and phosphorus content with high Contamination Factors. The Pollution Load Index values (1.3; 5.3; 2.5; 2.3) were indicative of multi-heavy metals pollution (Fe, Mn, Al, Cu, Zn, Cr and Ni) in mixed calcareous soils of the coastal area and they are exchangeable while they are immobilized or less mobile in inland pure ferralitic soils. For mixed calcareous soils of the coastal area, family pig breeding represents a drainage risk of soluble species (phosphorus, inorganic nitrogen, Fe, Mn, Al, Cu, Zn, Cr and Ni). For inland ferralitic soils, family pig breeding is more compatible with a sustainable management of the environment in Uvéa Island and by extension in volcanic tropical islands with respect to the investigated chemical elements.

Aerobic biotransformation of 3-methylindole to ring cleavage products by Cupriavidus sp. strain KK10

3-Methylindole, also referred to as skatole, is a pollutant of environmental concern due to its persistence, mobility and potential health impacts. Petroleum refining, intensive livestock production and application of biosolids to agricultural lands result in releases of 3-methylindole to the environment. Even so, little is known about the aerobic biodegradation of 3-methylindole and comprehensive biotransformation pathways have not been established. Using glycerol as feedstock, the soil bacterium Cupriavidus sp. strain KK10 biodegraded 100 mg/L of 3-methylindole in 24 h. Cometabolic 3-methylindole biodegradation was confirmed by the identification of biotransformation products through liquid chromatography electrospray ionization tandem mass spectrometry analyses. In all, 14 3-methylindole biotransformation products were identified which revealed that biotransformation occurred through different pathways that included carbocyclic aromatic ring-fission of 3-methylindole to single-ring pyrrole carboxylic acids. This work provides first comprehensive evidence for the aerobic biotransformation mechanisms of 3-methylindole by a soil bacterium and expands our understanding of the biodegradative capabilities of members of the genus Cupriavidus towards heteroaromatic pollutants.

Toxicity evaluation of pig slurry using luminescent bacteria and zebrafish

Biogas slurry has become a serious pollution problem and anaerobic digestion is widely applied to pig manure treatment for environmental protection and energy recovery. To evaluate environmental risk of the emission of biogas slurry, luminescent bacteria (Vibrio fischeri), larvae and embryos of zebrafish (Danio rerio) were used to detect the acute and development toxicity of digested and post-treated slurry. Then the ability of treatment process was evaluated. The results showed that digested slurry displayed strong toxicity to both zebrafish and luminescent bacteria, while the EC₅₀ for luminescent bacteria and the LC₅₀ for larvae were only 6.81% (v/v) and 1.95% (v/v) respectively, and embryonic development was inhibited at just 1% (v/v). Slurry still maintained a high level of toxicity although it had been treated by membrane bioreactor (MBR), while the LC₅₀ of larvae was 75.23% (v/v) and there was a little effect on the development of embryos and V. fischeri; the results also revealed that the zebrafish larvae are more sensitive than embryos and luminescent bacteria to pig slurry. Finally, we also found the toxicity removal rate was higher than 90% after the treatment of MBR according to toxicity tests. In conclusion, further treatment should be used in pig slurry disposal or reused of final effluent.

Genotoxicity in Astyanax bimaculatus (Twospot Astyanax) exposed to the waters of Engano River (Brazil) as determined by micronucleus tests in erythrocytes

Changes in aquatic environments are potentially large, and effects on biota are highly variable. In Santa Catarina State, Brazil, the main sources of pollution in headwaters are wastewater, pesticides, and animal waste, which contain chemical and organic additives, and there is little knowledge about their effects on aquatic organisms. This study was aimed at investigating the possible genotoxic effects of the waters of the Engano River through the micronucleus (MN) test in Astyanax bimaculatus erythrocytes. Samplings were performed at two sites on the river, and there were six temporal repetitions with collection of blood from six individuals per site/repetition. For the negative-control treatment, we used fish from organic culture; cyclophosphamide was inoculated to constitute the positive-control treatment. MN was obtained in 3,000 erythrocytes/individual. Kruskal-Wallis analysis of variance, Scott-Knott test, and Spearman correlation were employed for data analysis. We found 124 MN in fish from the river, with 70 and 54 MN, respectively, for each site and 16 and 59 MN in negative and positive controls, respectively. The results showed a statistical difference for the formation of MN between river fish and fish in the positive-control treatment. Considering the average MN, we found the formation of three distinct groups: (1) fish from site no. 1 and those in the negative-control group, (2) fish from site no. 2, and (3) fish in the positive-control group. The greater values of chromosomal damage were found during periods of lower rainfall. The test used indicated the presence in the water of substances likely to cause clastogenic and aneugenic effects.

Toxicity identification evaluation of anaerobically treated swine slurry: a comparison between Daphnia magna and Raphanus sativus

Anaerobic digestion does not efficiently reduce ionic compounds present in swine slurry, which could present a potential risk to aquatic ecosystems (surface runoff) and terrestrial ambient (irrigation). The objective of this study was to evaluate the ecotoxicological characteristics of anaerobically treated swine slurry using acute and chronic (epicotyl elongation) toxicity tests with Daphnia magna and Raphanus sativus and identification of suspected toxic compounds using the Toxicity Identification Evaluation (TIE) method. The evaluation was performed in three phases: physicochemical characterization of the slurry; acute/chronic toxicity testing with Daphnia magna and Raphanus sativus for each fraction of the TIE (cation and anion exchange columns, activated carbon, pH modification/aeration and EDTA) and identification of suspected toxic compounds. The anaerobically treated slurry contained concentrations of ammonium of 1,072 mg L(-1), chloride of 815 mg L(-1) and metals below 1 mg L(-1) with a D. magna acute toxicity (48h-LC50) of 5.3% and R. sativus acute toxicity (144h-LC50) of 48.1%. Epicotyl elongation of R. sativus was inhibited at concentrations above 25% (NOEC). The cation exchange reduced the toxicity and free ammonia by more than 90% for both bio-indicators. Moreover, this condition stimulated the epicotyl growth of R. sativus between 10% and 37%. In conclusion, the main compound suspected of causing acute toxicity in D. magna and acute/chronic toxicity in R. sativus is the ammonium. The findings suggest the need the ammonium treatment prior to the agricultural reuse of swine slurry given the high risk to contaminate the aquatic environment by runoff and toxicity of sensitive plants.

Investigation of copper speciation in pig slurry by a multitechnique approach

It is now well-known that copper (Cu) can accumulate on the surface of soils upon which pig slurry has been applied. This is due to the high quantity of Cu in pig slurry resulting from its use as a growth promoter in animal feeds. The mobility and bioavailability of Cu from pig slurry spreading can be better predicted by determining the speciation of this element in addition to its total concentration. The aim of this study was to present a multitechnique approach to investigate Cu speciation in pig slurry. First, size fractionation and chemical characterization of each size fraction were performed to complement results obtained in raw samples. Micro X-ray fluorescence spectroscopy (μXRF) highlighted the colocalization of Cu and sulfur (S). Finally, X-ray absorption near-edge structure spectroscopy (XANES) showed that Cu speciation in raw pig slurry and size fractions could be described by Cu(2)S and that its oxidation state is Cu(I). In addition, geochemical calculation demonstrated that chalcocite (Cu(2)S) was the major Cu species present under pig slurry lagoon physical-chemical conditions. This Cu speciation in pig slurry may be the main reason for the observed Cu accumulation at the soil surface.

A comparative evaluation of microalgae for the degradation of piggery wastewater under photosynthetic oxygenation

Two green microalgae (Scenedesmus obliquus and Chlorella sorokiniana), one cyanobacterium (Spirulina platensis), one euglenophyt (Euglena viridis) and two microalgae consortia were evaluated for their ability to support carbon, nitrogen and phosphorous removal in symbiosis with activated sludge bacteria during the biodegradation of four and eight times diluted piggery wastewater in batch tests. C. sorokiniana and E. viridis were capable of supporting the biodegradation of four and eight times diluted wastewater. On the other hand, while S. obliquus and the consortia isolated from a swine manure stabilization pond were only able to grow in eight times diluted wastewater, S. platensis and the consortium isolated from a high rate algal pond treating swine manure were totally inhibited regardless of the dilution applied. TOC removal efficiencies (RE) ranging from 42% to 55% and NH(4)(+)-RE from 21% to 39% were recorded in the tests exhibiting photosynthetic oxygenation. The similar oxygen production rates exhibited by the tested microalgae under autotrophic conditions (from 116 to 133mgO(2)L(-1)d(-1)) suggested that factors other than the photosynthetic oxygenation potential governed piggery wastewater biodegradation. Microalgal tolerance towards NH(3) was hypothesized as the key selection criterion. Further studies in a continuous algal-bacterial photobioreactor inoculated with C. sorokiniana, S. obliquus and S. platensis showed that C. sorokiniana, the species showing the highest NH(3)-tolerance, rapidly outcompeted the rest of the microalgae during the biodegradation of eight times diluted wastewater, achieving TOC and NH(4)(+)-RE comparable to those recorded in the batch biodegradation tests.

Combining size fractionation, scanning electron microscopy, and X-ray absorption spectroscopy to probe zinc speciation in pig slurry

Zinc occurs in high quantity in pig slurry since it is used as an essential micronutrient at high concentrations in animal feeds despite the low Zn assimilation by pigs. Zinc accumulation was measured in soil surface layers that had been amended with pig slurry, while also determining the phytotoxicity as well as the extent of groundwater quality degradation. To accurately predict the mobility and bioavailability of Zn derived from pig slurry spreading, the speciation of this element has to be assessed since the total concentration is not sufficient. This study involved a combination of techniques to investigate Zn speciation in pig slurry. Size fractionation was first performed to account for the complexity of pig slurry, and 75% of total Zn was detected in the 0.45- to 20-mum particle-size range. Then X-ray diffraction, scanning electron microscopy, coupled with energy dispersive spectrometer, and extended X-ray absorption fine structure analyses were combined to assess Zn speciation. The findings highlighted the presence of 49% Zn bound to organic matter, 37% amorphous Zn hydroxides [Zn(OH)(2)], and 14% sphalerite (ZnS).

Accumulation, subcellular distribution and toxicity of copper in earthworm (Eisenia fetida) in the presence of ciprofloxacin

Land application of wastes from concentrated animal feeding operations results in accumulation of copper (Cu) and antimicrobials in terrestrial systems. Interaction between Cu and antimicrobials may change Cu speciation in soil solution, and affect Cu bioavailability and toxicity. In this study, earthworms were exposed to quartz sand percolated with different concentrations of Cu and ciprofloxacin (CIP). Copper uptake by earthworms, its subcellular partition, and toxicity were studied. An increase in the applied CIP decreased the free Cu ion concentration in external solution and mortalities of earthworm, while Cu contents in earthworms increased. Copper and CIP in earthworms were fractionated into five fractions: a granular fraction (D), a fraction consisting of tissue fragments, cell membranes, and intact cells (E), a microsomal fraction (F), a denatured proteins fraction (G), and a heat-stable proteins fraction (H). Most of the CIP in earthworms was in fraction H. Copper was redistributed from the metal-sensitive fraction E to fractions D, F, G, and H with increasing CIP concentration. These results challenge the free ion activity model and suggested that Cu may be partly taken up as Cu-CIP complexes in earthworms, changing the bioavailability, subcellular distribution, and toxicity of Cu to earthworms.

Phytotoxic effects of sewage sludge extracts on the germination of three plant species

In order to evaluate the ability of three types of extracts to explain the ecotoxicological risk of treated municipal sewage sludges, the OECD 208A germination test was applied using three plants (Lolium perenne L., Brassica rapa L., and Trifolium pratense L.). Three equivalent batches of sludge, remained as dewatered sludge, composted with plant remains and thermally dried, from an anaerobic waste water treatment plant were separated. Samples from these three batches were extracted in water, methanol, and dichloromethane. Plant bioassays were performed and the Germination Index (GI) for the three plants was evaluated once after a period of 10 days. Germination in extracts was always lower than the respective controls. The germination in composted sludge (GI 40.9-86.2) was higher than the dewatered (GI 2.9-45.8), or thermally dried sludges (GI 24.6-64.4). A comparison of the germination between types of extracts showed differences for dewatered sludge with the three plants, where the water and methanol extracts had significantly lower germination than the dichloromethane extract. A higher half maximal effective concentration (EC50) in composted extracts was established, mainly in the water extract (EC50 431-490 g kg(-1)). On the contrary, the germination was strongly inhibited in the water extract of the dewatered sludge (EC50 14 g kg(-1)). The germination was positively correlated with the degree of organic matter stability of the parent sludge, and an inverse correlation was detected for total nitrogen, hydrolysable nitrogen and ammonium content. It is concluded that the phytotoxic effect of the water extract is more closely related to hydrophilic substances rather than lipophilic ones, and care must be taken with dewatered sludge application, especially with their aqueous eluates. Results obtained in this work show the suitability of the use of sludge extracts in ecotoxic assays and emphasize the relevance of sewage sludge stabilization by post-treatment processes.

Toxic effects of digested, composted and thermally-dried sewage sludge on three plants

In order to evaluate potential toxic effects of stabilized sewage sludge that are currently applied to agricultural soils, three types of municipal sewage sludge and one pig slurry were subjected to phytotoxicity assays using three plants (Brassica rapa, Lolium perenne and Trifolium pratense). Equivalent batches of aerobically and anaerobically-digested sludge (F) from two municipal wastewater treatment plants, were composted (C) or thermally dried (T). In addition, one anaerobically-digested and thermally-dried pig slurry (P) was tested. A seedling growth test was performed in accordance with the OECD Guideline 208A, using seed emergence and shoot length as endpoints to identify the inhibition of plants growing in increasing doses of sludge. A correlation analysis between EC50 and physico-chemical parameters or the pollutant burden of the biosolids was also calculated. In all tests, lower germination rates were observed for T. pratense than for L. perenne and B. rapa. A moderate stimulatory effect on shoot length at low doses was observed for the three plants. In these wastes, a strong positive correlation was found between higher values of EC50 (less toxicity) and the stability degree of their organic matter, and a negative correlation between EC50 and total N, hydrolysable N or NH4-N content. No correlations were found with heavy metal or organic pollutant content in those wastes. Results indicate that digested sludge, thermally-dried sludge and thermally-dried pig slurry have non-negligible short term phytotoxic effects, and confirm that composting is an effective sludge treatment for the reduction of phytotoxicity.

Dissolved and particulate fluxes of copper through the Morlaix river estuary (Brittany, France): mass balance in a small estuary with strong agricultural catchment

Dissolved and particulate copper were measured over an annual cycle (12 surveys between February 1998 and January 1999) in the Morlaix Estuary (Brittany, France). These variations were investigated in both the water column and the benthic compartment in order to calculate fluxes of copper within estuary. In the water column, dissolved and particulate copper concentrations ranged from 0.6 to 19.0 nM and from 0.03 to 2.3 micromol g(-1), respectively. In the benthic compartment, copper concentrations in superficial sediment varied from 0.04 to 0.32 micromol g(-1) and from 7.6 to 80.5 nM in the pore waters. The results show that copper contents in the water column reached levels commonly observed in estuaries affected by heavy industrial activities. Agricultural activities, extensively developed on the drainage basin, may be responsible for the copper excess. Mass balance of copper indicates that the metal accumulated within the estuary with a rate ranging from 97 to 119 kg yr(-1).

Determination of oxytetracycline and its degradation products by high-performance liquid chromatography-tandem mass spectrometry in manure-containing anaerobic test systems

This paper describes the development of a HPLC-MS-MS (ESI) method with baseline separation of oxytetracycline, 4-epi-oxytetracycline, alpha-apo-oxytetracycline and beta-apo-oxytetracycline using an XTerra column and an MeOH-MilliQ-water (containing 8 mM formic acid) mobile phase. Limits of quantification for aqueous standards were in the range of 0.004 to 0.008 microM. The linear range tested was 0.003 to 0.5 microM and in one case up to 17 microM. An experiment simulating the degradation of oxytetracycline in manure was set up and free concentrations of the four antibiotics were determined during 6 months. Oxytetracycline (>0.02 microM) was observed up till 6 months after spiking. No important increase in free concentrations of the degradation products was observed.

Sequestration of priority pollutant PAHs from sediment pore water employing semipermeable membrane devices

Semipermeable membrane devices (SPMDs) were employed to sample sediment pore water in static exposure studies under controlled laboratory conditions using (control pond and formulated) sediments fortified with 15 priority pollutant polycyclic aromatic hydrocarbons (PPPAHs). The sediment fortification level of 750 ng/g was selected on the basis of what might be detected in a sediment sample from a contaminated area. The sampling interval consisted of 0, 4, 7, 14, and 28 days for each study. The analytical methodologies, as well as the extraction and sample cleanup procedures used in the isolation, characterization, and quantitation of 15 PPPAHs at different fortification levels in SPMDs, water, and sediment were reported previously (Williamson, M.S. Thesis, University of Missouri-Columbia, USA; Williamson et al., Chemosphere (This issue--PII: S0045-6535(02)00394-6)) and used for this project. Average (mean) extraction recoveries for each PPPAH congener in each matrix are reported and discussed. No procedural blank extracts (controls) were found to contain any PPPAH residues above the method quantitation limit, therefore, no matrix interferences were detected. The focus of this publication is to demonstrate the ability to sequester environmental contaminants, specifically PPPAHs, from sediment pore water using SPMDs and two different types of fortified sediment.

HPLC-PFD determination of priority pollutant PAHs in water, sediment, and semipermeable membrane devices

High performance liquid chromatography coupled with programmable fluorescence detection was employed for the determination of 15 priority pollutant polycyclic aromatic hydrocarbons (PPPAHs) in water, sediment, and semipermeable membrane devices (SPMDs). Chromatographic separation using this analytical method facilitates selectivity, sensitivity (ppt levels), and can serve as a non-destructive technique for subsequent analysis by other chromatographic and spectroscopic techniques. Extraction and sample cleanup procedures were also developed for water, sediment, and SPMDs using various chromatographic and wet chemical methods. The focus of this publication is to examine the enrichment techniques and the analytical methodologies used in the isolation, characterization, and quantitation of 15 PPPAHs in different sample matrices.

Determination of the distribution coefficient (log Kd) of oxytetracycline, tylosin A, olaquindox and metronidazole in manure

Olaquindox (log Kow = -2.3) and metronidazole (log Kow = -0.1) both have low tendencies to sorp to particles in manure. This corresponds with the negative log Kow values of these antibiotics. Tylosin (log Kow = 1.63) and oxytetracycline (log Kow = -1.12) sorp relatively strongly to the manure particles and have log Kd values between 1.5 and 2.0. The tendency to bind to manure was ranked after increasing binding as follows: metronidazole < olaquindox << tylosin A and oxytetracycline. This order of ranking is consistent with results of sorption in soil. Our experiments illustrate that for some antibacterial agents estimation of the partitioning coefficients, Kd, cannot be made from Kow and f(oc) alone. Sorption of oxytetracycline to manure is much higher than expected from the negative log Kow value of the compound. It is believed that sorption of oxytetracycline to manure is influenced by ionic binding to divalent metal ions as such Mg2+ and Ca2+ as well as other charged compounds in the matrix. Binding of oxytetracycline to soil is stronger than the binding to manure. This is most likely due to the strong mineral related metal complexes formed between soil, metal ion and oxytetracycline. These complexes are not known to exist in manure. The relatively strong sorption of tylosin A to manure corresponds with data found for soil sorption of tylosin. Tylosin has a log Kow value of 2.5, thus it is not surprising that this drug binds strongly to manure.

Evaluation of the application of pig slurry to an experimental crop using agronomic and ecotoxicological approaches

The agronomic and ecotoxicological effects of the application of pig (Sus scrofa) slurry during a maize (Zea mays L.) crop cycle under conditions of forced irrigation were evaluated. The 0.2-ha experimental area, of typical xerofluvent soil and of known vulnerability to nitrate (NO3-) contamination, was divided into 12 plots and provided with water measurement instruments (TDR-probes, vertical tensiometers, and ceramic candles). Samples of soil, water, soil organisms, and the crop were subjected to analytical, agronomic, and biological test procedures. The following fertilizer treatments were applied to triplicate plots: urea (U;170 kg N ha(-1)), and an optimized (P1; 162 kg N ha(-1)) and triple (P3; 486 kg N ha(-1)) dose of pig slurry. Unfertilized plots (P0) served as controls. Calculation was made of seasonal drainage and leached NO3- and sodium losses during the experimental period. Conductivity, heavy metal concentration, hardness, pH, and redox potential were determined in soil solutions. The ecotoxicological evaluation of the soil solution and matrix was based on ecotoxicity bioassays and the quantification of organic and inorganic compounds [phenols, indols, polychlorinated biphenyls (PCBs)]. The results suggest that the P3 treatment is highly contaminating due to the leaching of nitrates and increased soil salinity. Despite the fact that a Folsomia candida reproduction test indicated chronic ecotoxicological effects on the soil in plots treated with P1 and P3, the absence of organic compounds suggests that these effects may be attributable to contaminants not considered in this study.