Development Method for Extracting and Analyzing Antibiotic and Hormone Residues from Treated Wastewater Sludge and Composted Biosolids

Extraction and analysis methods have been developed for the detection of the following four antibacterial agents and two natural estrogens in treated municipal wastewater sludge and commercial compost: sulfamethoxazole (SMX), sulfadimethoxine (SDM), tetracycline (TET), oxytetracycline (OXY), estrone (E1), and 17??-estradiol (E2). The antibiotics and estrogens were extracted from secondary sludge and mixed compost using ultrasonic solvent extraction. Citric acid (pH?4.7) and methanol were used as extraction buffer, followed by tandem-solid-phase extraction cleanup, strong anion exchange?+?hydrophilic?Clipophilic balance for antibiotics and CarboPrep/NAX for estrogens. For quantification, two different methods were employed, using HPLC?CMS/MS, with an electrospray ionization source for antibiotics and an atmospheric-pressure chemical ionization source for estrogens. Recoveries were 11?C31% for the sulfonamides (SMX and SDM) and tetracyclines (TET and OXY) and 30?C59% for the estrogens (E1 and E2) over the entire method. Limits of detection for the extraction method were in the nanogram per gram range for dry weight sludge and compost samples. Neither of the two sulfonamide antibiotics was detected in secondary sludge or mixed compost samples. Estrogens were found in compost in amounts of 160?±?65?ng/g (E1) and 21?±?3?ng/g (E2), but not in sludge. The tetracyclines, as well as what is believed to be the 4-epimer of OXY, were found in both sludge and compost in amounts of 1.57?±?0.67 and 2.95?±?0.42???g/g (TET), 0.56?±?0.12 and 6.51?±?0.52???g/g (OXY), and 7.60?±?1.68 and 1.35?±?0.24???g/g (4-epi-OXY), respectively. These results indicate that sorption-prone compounds are not removed during the wastewater treatment process and can persist through sludge digestion and that the composting process does not sufficiently eliminate these particular contaminants. Thus, biosolids (even composted) are an additional source of drug residues leaching into the environment, and it must be considered while using biosolids as fertilizer.     

Occurrence of Emerging Contaminants in Brazilian Drinking Waters: A Sewage-To-Tap Issue

The goal of this work was to investigate the occurrence of emerging contaminants in drinking water of the city of Campinas, Brazil. Tap water samples were analyzed using SPE-GC-MS for 11 contaminants of recent environmental concern. Six emerging contaminants (stigmasterol, cholesterol, bisphenol A, caffeine, estrone, and 17β-estradiol) were found in the samples. The latter two were detected only during the dry season, with concentrations below quantification limits. Stigmasterol showed the highest average concentration (0.34?±?0.13?µg L^?1), followed by cholesterol (0.27?±?0.07?µg L^?1), caffeine (0.22?±?0.06?µg L^?1), and bisphenol A (0.16?±?0.03?µg L^?1). In Campinas, where surface drinking water supplies receive large amounts of raw sewage inputs, the emerging contaminants levels in drinking waters were higher than median values compiled for drinking and finished water samples around the world.     

Wet and Dry Deposition Fluxes of Polychlorinated Biphenyls (PCBs) in an Urban Area of Turkey

Atmospheric polychlorinated bihenyls (PCBs) deposit by dry and wet deposition mechanisms, and therefore they constitute a significant polluting source for lands and surface waters. Various samplers have been used to determine the PCB pollution level resulting from deposition. In the presented study, a modified wet deposition sampler (WDS) was used for sampling both wet and dry deposition samples with the same instrument by which wet deposition reservoir of the WDS is opened and dry deposition reservoir is closed when rain starts. Wet and dry deposition samples were collected between June 2008 and June 2009. In the samples taken from BUTAL which is known as an urban area with heavy traffic, ??PCB dry deposition fluxes were determined as 18?±?10 ng/m²??day, and wet deposition fluxes for dissolved and particle phase were measured as 480?±?1,185 and 475?±?1,000 ng/m²??day, respectively. The dissolved and particle-phase PCB concentrations in rain were 10?±?13 and 13?±?14 ng/l, respectively. The contribution of wet deposition to total PCB deposition was determined as 52%. PCB concentrations in the ambient air were measured to be 370?±?200 and 20?±?20 pg/m³ for gas and particle phases, respectively. Washout ratio was determined by proportioning rain concentration to concentration in air. The washout ratios of the samples were between 1,675?C311,800 and 12,775?C2,511,120 for dissolved and particulate phases, respectively.     

Removal of Zinc from Tidal Water by Sediments of a Mangrove Ecosystem: A Radiotracer Study

The removal of ⁶⁵Zn from tidal water by underlaying sediment cores collected in a mangrove forest and a tidal creek that drains this forest in Sepetiba Bay (SE Brazil) was investigated. After 30-h experiments in laboratory microcosms, the ⁶⁵Zn half-removal times from tidal creek and mangrove forest sediments were 8.7?±?1.8 and 9.2?±?0.9 h respectively. Depth penetration of ⁶⁵Zn was mainly restricted to the upper 3 cm in mangrove forest cores, while detectable ⁶⁵Zn activities were found in all layers (0–7 cm depth) of tidal creek cores. An unexpected ⁶⁵Zn release back to the overlaying water was observed for one of the tidal creek experiments in the 12–18 h interval (corresponding to a return of 17% of the initial ⁶⁵Zn activity in overlaying water), suggesting a reversibility of the ⁶⁵Zn removal process (e.g., by adsorption) in tidal creek sediments. The results indicate that mangrove-vegetated sediments allowed a lower vertical mobility of Zn than observed in creek sediments and mangrove sediments appear to be less susceptible to a reversion in the process of zinc removal from overlaying water, suggesting a greater capacity to retain this metal near the water–sediment interface. This first radiotracer approach on the mangrove sediments removal of Zn from tidal waters supports earlier experimental studies employing stable Zn, contributing for a better understanding of the metal uptake kinetics by such sediments and suggesting that these sediments act as active sinks for trace metals.     

Transport of Escherichia coli and F-RNA Bacteriophages in a 5-M Column of Saturated, Heterogeneous Gravel

The relative transport and attenuation of bacteria, bacteriophages, and bromide was determined in a 5?m long?×?0.3?m diameter column of saturated, heterogeneous gravel. The average pore velocity (V), longitudinal dispersivity (?? _x ), and total removal rate (??) were derived from the breakthrough curves at 1, 3, and 5?m, at a flow rate of 24.8?L?h^?1. The experiments largely confirmed the differences in transport and attenuation patterns among bacteria, phages, and bromide, and between colloid-associated and ??free?? microorganisms, previously observed in a study using homogeneous pea gravel. Cultured Escherichia coli J6-2 cells were transported faster than phage MS2 and bromide, consistent with velocity enhancement of the larger particles. The evidence for velocity enhancement of phage MS2 compared with bromide was less conclusive, with some evidence of retardation of the phage as a result of adsorption?Cdesorption processes in the finer media. On average, phage in sewage and adsorbed to kaolin particles were transported faster than free phage, suggesting that most sewage phage are adsorbed to colloids. However, average velocities of cultured and sewage E. coli differed far less, suggesting that most E. coli in sewage exist as individual (non colloid-associated) cells. There was no conclusive evidence that the wider pore size range in the heterogeneous mixture compared with pea gravel increased velocity enhancement effects. Removal rates of free phage were far higher than in the pea gravel, and were attributed to adsorption in the finer materials. Equivalent increases in removal of cultured and sewage E. coli and colloid-associated phage were attributed to straining in finer materials and settling in quiescent zones. Inactivation (??) rates (determined in the pea gravel study) indicated little contribution to removal of either free or attached microorganisms. The results showed the importance of association with colloids in determining the relative transport of bacteria and viruses in alluvial gravels.     

Microbially Mediated Degradation of Common Pharmaceuticals and Personal Care Products in Soil Under Aerobic and Reduced Oxygen Conditions

Biological degradation rates of estrogen compounds and common pharmaceutical and personal care products (PPCPs) were examined in soils with a long history of exposure to these compounds through wastewater effluent and in soil not previously exposed. Biological degradation rates over 14 days were compared under aerobic and anaerobic conditions. Estrogen compounds including estrone, 17??-estradiol, estriol, and 17??-ethinylestradiol exhibited rapid degradation by soil microorganisms in both aerobic and anaerobic conditions. Rapid degradation rates for estrone, estriol, and 17??-ethinylestradiol occurred in pre-exposed soil under aerobic conditions; half-lives calculated under these conditions were 0.6, 0.7, and 0.8 day, respectively. Unexposed soil showed similar or slightly longer half-lives than pre-exposed soil under aerobic conditions. The exception was 17??-estradiol; in all treatments, degradation in unexposed soil resulted in a shorter half-life (2.1 versus 2.3 days). Anaerobic soils exhibited high biological degradation of estrogens as well. Half-lives of all estrogens ranged from 0.7 to 6.3 days in anaerobic soils. Triclosan degraded faster under aerobic conditions with half-lives of 5.9 and 8.9 days in exposed and unexposed soil. Under anaerobic conditions, triclosan half-lives were 15.3 days in unexposed and 28.8 days in exposed soil. Ibuprofen showed the least propensity toward biological degradation than other chemicals tested. Biological degradation of ibuprofen was only observed in unexposed soil; a half-life of 41.2 days was determined under anaerobic conditions and 121.9 days under aerobic conditions. Interestingly, unexposed soil exhibited a greater ability under anaerobic conditions to biologically degrade tested compounds than previously exposed soil.     

Degradation of 17β-Estradiol and its Metabolites by Sewage Bacteria

Natural estrogens (e.g., 17β-estradiol or 1,3,5[10]-estratriene-3,17β-diol) have been suggested as one of the major groups of substances that cause endocrine disruption in wildlife. There is little information in the open literature on the fate of natural estrogens in the environment, a fact thathinders the assessment of their ultimate impact on the ecosystem. Aerobic and anaerobic batch experiments involving a 17β-estradiol-degrading culture and a supernatant of activated sludge from a local sewage treatment plant (Burlington, Ontario) were undertaken to assess the persistenceof 17β-estradiol (E₂) and its 5 metabolites. The batch experiments showed that E₂ and the metabolites werenot persistent and could be rapidly degraded by sewage bacteria.Biodegradation of E₂ by sewage bacteria appeared to initiate at the D ring of E₂, leading to the formation of the major metabolite estrone (E₁). No other major degradation products were noted. However, during the very earlystages of E₂ degradation by sewage bacteria, a previouslyunreported metabolite, X1 (5-hydroxy-15-methyl-13-oxatetracyclo[8.7.0.0 <2,7> .0. <11,15>]-heptadeca-2(7),3,5-trien-14-one), was observed. X1 appeared to be a labilemetabolite with a lactone structure, but its significance in thebiodegradation of E₂ remained to be elucidated. With theobservation of the new metabolite X1, a metabolic pathway of E₂ by sewage bacteria was proposed. Conditions (e.g., aerobic and anaerobic environment) governing the persistence of E₂ in sewage were also investigated. Results in this study suggest that the risk of extensive accumulation of natural estrogens normally found in sewage effluents in theenvironment is small, due to their ready biodegradation.     

Nitrogen dynamics of anaerobically digested slurry used to fertilize paddy fields

To determine nitrogen (N) fate and environmental impact of applying anaerobic digestion slurry (ADS) to rice paddy (Oryza sativa L.), a field experiment was established using three treatments based on contrasting N application rate. The ADS (with ammonium-N accounting for >80 % of total N) treatment at a conventional application rate of 270 kg N?ha^?1 was compared to a negative control (no N fertilizer) and a positive control of urea applied at 270 kg N?ha^?1. The N budget showed the following distribution of applied N from ADS and urea: 41.3?±?5.1 % for ADS and 36.6?±?4.4 % for urea recovered by the rice plant (including straw, grain, and root), 16.4?±?3.7 % for ADS and 7.4?±?1.8 % for urea lost via ammonia volatilization, 0.26?±?0.15 % for ADS and 0.15?±?0.12 % for urea lost by direct N₂O emission, 1.9?±?0.5 % for ADS and 2.3?±?0.8 % for urea leached downward, 0.70?±?0.15 % for ADS and 0.67?±?0.12 % for urea discharged with floodwater drainage, and 39.4?±?8.4 % for ADS and 53.0?±?9.1 % for urea retained by soil or lost by N₂ emission. Compared to urea application, ADS application impacts the environment mainly through gaseous N losses rather than water N losses. ADS application had a positive impact on rice grain yield and reduced chemical fertilizer use. Considering the wide distribution of paddy fields and the ever-increasing quantities of ADS, ADS may serve as a valuable N source for rice cultivation, although mitigating ammonia and N₂O losses should be further investigated.     

Soil carbon stocks and their primary origin at mature mangrove ecosystems in the estuary of Fukido River,Ishigaki Island,southwestern Japan

ABSTRACT

Mangrove ecosystems play an important role in carbon (C) accumulation in tropical and subtropical regions. Below-ground deep anoxic soil is especially important for C accumulation. However, quantitative data on below-ground soil C stocks in mangrove ecosystems are lacking compared with data on above-ground biomass. In addition, soil C accumulation processes in mangrove ecosystems have not been sufficiently clarified. In this study, we quantified soil C stocks and focused on the mass of fallen litter and below-ground roots, which are produced by tree and that may directly influence soil C stocks in a mature subtropical mangrove in the estuary of Fukido River, Ishigaki Island, southwestern Japan. The principal species in this study site were Bruguiera gymnorhiza and Rhizophora stylosa, and total above-ground biomass at the site was 80.7 ± 1.3 (mean ± SD) Mg C ha^?1 over the period from 2014 to 2016. Litter was collected in six litter traps from May 2013 to November 2016, it ranged from 7.8 to 11.5 Mg C ha^?1, with the major proportion of litter being from foliage (leaves and stipules). The root C density at 90-cm depth was 27.1 ± 11.3 Mg C ha^?1. The soil C stock in the mangrove forest at a depth of 90 cm at the study site was 251.0 ± 34.8 Mg C ha^?1, and it seems to be lower value in the tropical region but it to be higher in subtropical East Asian mangrove sites. Dead roots, especially dead fine roots, but not fallen litter, were significantly positively correlated with soil C stocks. The δ¹³C values obtained from soils ranged from ?29.3‰ to ?27.0‰; these values are consistent with those for below-ground fine roots. These results strongly suggest that dead fine roots could be a main factor controlling soil C stocks at this study site.     

Kinetic and Product Studies of the Reactions of NO2, with Hg0 in the Gas Phase in the Presence of Titania Micro-Particle Surfaces

As global mercury emissions from coal fire power plants increase with the continuing rise of coal consumption, mercury capture methods are being developed to prevent mercury??s escape into the atmosphere. Titanium dioxide (TiO₂) in the presence of ultra violet light (UV-A; ?? _max ??360?nm) and oxygen will capture mercury as the solid product HgO_(s). Testing the effects of TiO₂ in the presence of other pollutants has so far been limited. We have performed kinetic and product studies of mercury adsorption in the presence of the gaseous flue co-pollutant NO_2(g). We extensively studied the gas-phase reaction of NO₂(g) with Hg _(g) ⁰ . We compared the gas-phase reaction to the same reaction performed in the presence of thin TiO₂ particle surfaces from 0 to 100?% relative humidity. The second-order rate constant was measured to be k?=?(3.5?±?0.5)?×?10^?35?cm⁶ molecules^?2?s^?1, independent of the presence of titania or the total surface area available for adsorption. Exposure of NO_2(g) to titania surfaces that were already saturated in captured mercury (HgO_(s)) increased total mercury uptake onto the surface. We discuss the implications of this study to the capture of mercury emissions prior to release to the atmosphere.     

Atmospheric Total Suspended Particulate Trace Element Identification by XRF at Ilha Grande, State of Rio De Janeiro, Brazil

Phosphorus, manganese, sulfur (S), lead, and strontium of atmospheric total suspended particulate matter, sampled during the rainy season and the dry season 2002 at the Ilha Grande Island (Rio de Janeiro State, Brazil) have been analyzed by XRF techniques. The results showed total mean concentrations of 27?±?16 ng P m^-3, 11?±?7 ng Mn m^-3, 159?±?126 ng S m^-3, 4.3?±?2.6 ng Pb m^-3, and 208?±?148 ng Sr m^-3. Generally, there is no clear influence of the two different climatic periods on the concentrations of most analyzed trace elements, with exception of sulfur the mean concentration of which, during the dry season, is about 60% higher than during the rainy season. This is probably due to biomass burning, a common practice in the Brazilian Southeast and Amazon region and/or to the presence of marine aerosols. The linear correlation coefficients strongly suggest the same source for P, Pb, and Mn. Some Pb, Mn, and P concentrations are in the range of typical values of urban areas. Potential sources of such elements are the urban and industrial emissions from the States of Rio de Janeiro and/or São Paulo.     

Phosphorus Release and Equilibrium Dynamics of Canal Sediments within the Everglades Agricultural Area, Florida

High phosphorus (P) in surface drainage water from agricultural and urban runoff is the main cause of eutrophication within aquatic systems in South Florida, including the Everglades. While primary sources of P in drainage canals in the Everglades Agricultural Area (EAA) are from land use application of agricultural chemicals and oxidation of the organic soils, internal sources from canal sediments can also affect overall P status in the water column. In this paper, we evaluate P release and equilibrium dynamics from three conveyance canals within the EAA. Incubation and flux experiments were conducted on intact sediment cores collected from four locations within the Miami, West Palm Beach (WPB), and Ocean canal. After three continuous exchanges, Miami canal sediments reported the highest P release (66?±?37 mg m^?2) compared to WPB (13?±?10 mg m^?2) and Ocean (17?±?11 mg m^?2) canal over 84 days. Overall, the P flux from all three canal sediments was highest during the first exchange. Miami canal sediments showed the highest P flux (2.4?±?1.3 mg m^?2 day^?1) compared to WPB (0.83?±?0.39 mg m^?2?d^?1) and Ocean canal sediments (0.98?±?0.38 mg m^?2 day^?1). Low P release from WPB canal sediments despite having high TP content could be due to carbonate layers distributed throughout the sediment column inhibiting P release. Equilibrium P concentrations estimated from the sediment core experiment corresponded to 0.12?±?0.04 mg L^?1, 0.06?±?0.03 mg L^?1, and 0.08?±?0.03 mg L^?1 for Miami, WPB, and Ocean canal sediments, respectively, indicating Miami canal sediments behave as a source of P, while Ocean and WPB canal sediments are in equilibrium with the water column. Overall, the sediments showed a significant positive correlation between P release and total P (r?=?0.42), Fe_ox (r?=?0.65), and Al_ox (r?=?0.64) content of sediments. The contribution of P from the three main canals sediments within the EAA boundary corresponded to a very small portion of the total P load exiting the EAA. These estimates, however, only take into consideration diffusive fluxes from sediments and no other factors such as canal flow, bioturbation, resuspension, and anaerobic conditions.     

DDT in Biota of Paranagu�� Bay, Southern Brazil: Recent Input and Rapid Degradation

The presence of recent dichlorodiphenyltrichloroethane (DDT) inputs is established for Paranaguá Bay biota, i.e. bivalves, fish and one sponge. Values ranged from 6.9 to 156.2 ng ??DDT/g dry weight. Three fish species analysed showed ??DDT values from 36.8 to 92.1 ng/g dry weight. The highest contents (up to 156.2 ng ??DDT/g dry weight) were found for mangrove oysters (Crassostrea rhizophorae) at locations affected by sewage discharge from Paranaguá City. Turtles as herbivores were not affected by this input with values of 0.7 and 2.2 ng ??DDT/g dry weight. The areal distribution of samples suggests that usage of DDT is widespread around the bay. Fresh DDT input is degraded to DDE and DDD within approximately 5 months.     

Influence of a Marine Diatom on the Embryonic Toxicity of 17α-Ethynylestradiol to the Abalone Haliotis diversicolor supertexta

The embryos of a marine abalone, Haliotis diversicolor supertexta, were exposed to a typical environmental estrogen, 17??-ethynylestradiol (EE2), for 96?h, to examine the acute toxicity of EE2 to the embryogenesis of the abalone. A marine diatom, Navicula incerta, was used in the test media as settlement substrate and food for the abalone larvae. During the embryo culture, more than 30?% of EE2 could be removed from the test media by the diatom, mainly via biodegradation, leading to a decrease of water-borne exposure dose. Further, the exposure concentrations of EE2 around the living microenvironment of the abalone larvae could be magnified 350?C468 times after the larvae settled on the diatom, as indicated by the bioconcentration factors of EE2 in the diatom. Increased bioaccumulation of EE2 in the diatom caused greater inhibition on the metamorphosis of the abalone larvae by enhancing the uptake of EE2 in the larvae via dietary exposure, while declined water-borne exposure dose did not affect the embryonic toxicity of EE2 and its uptake in the abalone larvae. The 96-h median effective concentration of EE2 to the metamorphosis of the abalone larvae was 10.01???g?L^?1, when the exposure doses in both the test media and the diatom were controlled stable. The 96-h hazard concentration for 5?% of the species was 1.20???g?L^?1, which was still higher than but close to the reported upper contamination level of EE2 and could be employed as the safety threshold for the metamorphosis of the abalone embryos.     

Fluxes and production pathways of nitrous oxide in different types of tropical forest soils in Thailand

Nitrous oxide (N₂O) emissions from the soil surface of five different forest types in Thailand were measured using the closed chamber method. Soil samples were also taken to study the N₂O production pathways. The monthly average emissions (±SD, n?=?12) of N₂O from dry evergreen forest (DEF), hill evergreen forest (HEF), moist evergreen forest (MEF), mixed deciduous forest (MDF) and acacia reforestation (ARF) were 13.0?±?8.2, 5.7?±?7.1, 1.2?±?12.1, 7.3?±?8.5 and 16.7?±?9.2?µg N m^?2 h^?1, respectively. Large seasonal variations in fluxes were observed. Emission was relatively higher during the wet season than during the dry season, indicating that soil moisture and denitrification were probably the main controlling factors. Net N₂O uptake was also observed occasionally. Laboratory studies were conducted to further investigate the influence of moisture and the N₂O production pathways. Production rates at 30% water holding capacity (WHC) were 3.9?±?0.2, 0.5?±?0.06 and 0.87?±?0.01?ng N₂O-nitrogen (N) g-dw^?1day^?1 in DEF, HEF and MEF respectively. At 60% WHC, N₂O production rates in DEF, HEF and MEF soils increased by factors of 68, 9 and 502, respectively. Denitrification was found to be the main N₂O production pathway in these soils except in MEF.     

Concentrations of Free and Conjugated Estrogens at Different Landscape Positions in an Agricultural Watershed Receiving Poultry Litter

Animal hormones can enter the aquatic environment along with runoff as a result of manure or litter application on agricultural landscapes. Our understanding of the transport of these hormones and their concentrations at various points along the watershed drainage is however limited. We investigated the transport of naturally produced poultry hormones in an agricultural watershed located on coastal plain soils of Delaware receiving land application of raw poultry manure. The objective of this study was to determine the concentrations of free and conjugated forms of estrogens in agricultural runoff at selected landscape positions in the agricultural watershed. Estrogen concentrations were determined for surface water, soil water, and runoff sediment. Estrogen forms that were analyzed were: Estrone (E1), Estradiol (E2?? and E2??), Estriol (E3), and their sulfate and glucuronide conjugates. Poultry litter application occurred at a rate of 9 Mg ha^?1 in early spring (April 2010). Sampling was performed for surface runoff, subsurface drainage, and sediment for nine storm events extending over 187 days before and after manure application (March?COctober 2010). Runoff was collected from the field edge, upland and lowland riparian positions and from the stream. Samples were analyzed by for liquid chromatography with tandem mass spectrometry (LC-MS/MS). Concentrations of estrogens were low (<20 ng l^?1) for most of the samples and decreased from the field edge into the riparian zone. Estrogens were not detected in soil water and runoff sediments. Overall, this study suggests that manure application practices at our sites in Delaware such as incorporation of litter into the soil likely reduced the concentrations of estrogens in runoff and reduced the threat posed to aquatic ecosystems.     

Analysis and Occurrence of Endocrine Disruptors in Brazilian Water by HPLC-Fluorescence Detection

A method for simultaneous analysis of bisphenol A (BPA) and 17α-ethinylestradiol (EE2) in water supply was developed using solid-phase extraction and high-performance liquid chromatography with fluorescence detection. The linearity was evaluated between 2.5 and 200 μg L^?1 (r> for the analytes. The limits of quantification were 1.5 and 2.1 ng L^?1 for BPA and EE2, respectively. The extraction was made with C18 cartridges, and recoveries obtained varied between 70 and 102 % for the strengthening of 5 μg L^?1. After the validation, the method was applied in the determination of pollutants in surface water and water supply of Sao Luis, Brazil, where BPA was found in two of the eight samples analyzed, with concentrations of 1.11 and 3.61 μg L^?1.     

Ammonia,Nitrous Oxide,Carbon Dioxide and Methane Emissions from Commercial Broiler Houses in Mediterranean Portugal

Limited data are available on ammonia (NH₃), nitrous oxide (N₂O), carbon dioxide (CO₂) and methane (CH₄) emissions from poultry housing in Mediterranean countries. The aim of the present study was to assess the NH₃, N₂O, CO₂ and CH₄ emission rates from commercial breeding hen and broiler houses under Mediterranean climate conditions. Research was conducted at one commercial breeding hen house and in two commercial broiler houses located in central Portugal. The environmental conditions, gas concentrations and ventilation rates were measured in the cold (8.0?±?2.1 °C) and hot (20.7?±?1.9 °C) season for the breeding hen house, whereas for the two broiler houses, measurements were made during one fattening cycle in the fall (17.3?±?1.7 °C) season. Results showed that the annual average emission rates for breeding hen and broiler houses were 0.52?±?0.27 and 0.06?±?0.01 for NH₃, 0.030?±?0.042 and 0.006?±?0.001 for N₂O, 169.6?±?56.2 and 58.0?±?15.1 for CO₂ and 0.092?±?0.131 and 0.0113?±?0.0002 g day^?1 bird^?1 for CH₄, respectively. The N₂O emission rates observed in breeding hen houses may have been overestimated, being higher than previously reported for Mediterranean countries.     

Fluoride Removal from Aqueous Solutions by a Carbonaceous Material from Pyrolysis of Sewage Sludge

Contact time, pH, fluoride concentration, and sorbent dose effects on the removal of fluoride ions by a carbonaceous material obtained from pyrolysis of sewage sludge (CM) were evaluated. Equilibrium was reached after 18?h of contact time and the maximum sorption was found at pH_eq?=?7.06?±?0.08, which corresponds to the zero charge point of the CM. The highest efficiency in the sorption system for fluoride removal (2.84?±?0.03?mg?F^?? $ g_{{CM}}^{{ - 1}} $ ) was found with 0.4?g_CM?L^?1 and with 20?g_CM?L^?1, 82.2?±?0.5% of fluoride was removed. The kinetic data of the process could be fitted to the pseudosecond order and the intraparticle mass transfer diffusion models, whereas isotherm to the Langmuir?CFreundlich equation. These results indicate that the mechanism is chemisorption on a heterogeneous material. Fluoride ions were best partially desorbed using a bicarbonate ions solution and the material was partially regenerated by using a solution of HCl (pH?=?1).     

Spatiotemporal Variations in Nitrous Oxide Emissions from an Open Fen on the Qinghai–Tibetan Plateau: a 3-Year Study

To understand spatial and temporal variations of nitrous oxide (N₂O) fluxes, we chose to measure N₂O emissions from three plant stands (Kobresia tibetica, Carex muliensis, and Eleocharis valleculosa stands) in an open fen on the northeastern Qinghai?CTibetan plateau during the growing seasons from 2005 to 2007. The overall mean N₂O emission rate was about 0.018?±?0.056?mg?N?m^?2?h^?1 during the growing seasons from 2005 to 2007, with highly spatiotemporal variations. The hummock (K. tibetica stand) emitted N₂O at the highest rate about 0.025?±?0.051?mg?N?m^?2?h^?1, followed by the hollow stands: the E. valleculosa stand about 0.012?±?0.046?mg?N?m^?2?h^?1 and the C. muliensis stand about 0.017?±?0.068?mg?N?m^?2?h^?1. Within each stand, we also noted significant variations of N₂O emission. We also observed the significant seasonal and inter-annual variation of N₂O fluxes during the study period. The highest N₂O emission rate was all recorded in July or August in each year from 2005 to 2007. Compared with the mean value of 2005, we found the drought of 2006 significantly increased N₂O emissions by 104 times in the E. valleculosa stand, 45 times in K. tibetica stand, and 18 times in the C. muliensis stand. Though there was no significant relation between standing water depths and N₂O emissions, we still considered it related to the spatiotemporal dynamics of soil water regime under climate change.