Nutrient Dynamics in Jiaozhou Bay

Three cruises were carried out in Jiaozhou Bay (JZB) in the neap tide in October 2002 (fall) and in both neap and spring tides in May 2003 (spring) to understand the relative importance of external nutrient inputs versus physical transport and internal biogeochemical processes. Nutrients (, , , , silicic acid, total dissolved nitrogen (TDN) and phosphorus (TDP), dissolved organic nitrogen (DON) and phosphorus (DOP)) were measured. The concentrations of nutrients were higher in the northern part than in the southern part. High concentrations of and DON in JZB demonstrated the anthropogenic input. Ambient nutrient ratios indicated that the potential limiting nutrients for phytoplankton growth were silicon, and then phosphorus. Nutrients showed an obvious tidal effect with low values at flood tide and high values at ebb tide. Nutrient elements were transported into JZB in the north and output in the south (i.e., into the Yellow Sea), which varied with season, tidal cycle and investigation sites. Water exchange between JZB and the Yellow Sea exports , and DON out of JZB, while it inputs , silicic acid and DOP into JZB. Nutrient budgets demonstrate that riverine input and wastewater discharge are major sources of nutrients, while residual flow is of minor importance in JZB ecosystem. JZB is a sink for the nutrient elements we studied except for DON. Stoichiometric calculations demonstrate that JZB is a net autotrophic system.     

Nitrogen Saturation of Terrestrial Ecosystems: Some Recent Findings and Their Implications for Our Conceptual Framework

The consequences of nitrogen (N) enrichment for terrestrial and freshwater ecosystems are of increasing concern in many areas due to continued or increasing high emission rates of reactive N. Within terrestrial ecosystems various conceptual frameworks and modelling approaches have been developed which have enhanced our understanding of the sequence of changes associated with increased N availability and help us predict their future impacts. Here, some recent findings are described and their implications for these conceptual frameworks and modelling approaches discussed. They are: (a) an early loss of plant species that are characteristic of low N conditions as N availability increases and a loss of species with high N retention efficiencies (so called N ‘filters’), (b) suppression of microbial immobilisation of deposited due to increased availability in the early stages of N saturation, (c) the early onset of leaching due to these changes (a and b above) in both plant and microbial functioning, (d) reduced sensitivity of vegetation to N additions in areas with high historical N deposition, (e) delayed changes in soil C:N changes due to increased net primary productivity and reduced decomposition of soil organic matter. Some suggestions of early indicators of N saturation are suggested (occurrence of mosses; ratio in surface soils) which indicate either a shift in ecosystem function and/or structure.     

Acid Rain in Downtown São Paulo City, Brazil

During the period from July 2002 to June 2004, the chemical characteristics of the rainwater samples collected in downtown São Paulo were investigated. The analysis of 224 wet-only precipitation samples included pH and electrical conductivity, as well as major ions (Na⁺, $ \rm NH^{ + }_{4} During the period from July 2002 to June 2004, the chemical characteristics of the rainwater samples collected in downtown S?o Paulo were investigated. The analysis of 224 wet-only precipitation samples included pH and electrical conductivity, as well as major ions (Na⁺, , K⁺, Ca²⁺, Mg²⁺, Cl⁻, , ) and carboxylic acids (acetic, formic and oxalic) using ion chromatography. The volume weighted mean, VWM, of the anions , and Cl⁻ was, respectively, 20.3, 12.1 and 10.7 μmol l⁻¹. Rainwater in S?o Paulo was acidic, with 55% of the samples exhibiting a pH below 5.6. The VWM of the free H⁺ was 6.27 μmol l⁻¹), corresponding to a pH of 5.20. Ammonia (NH₃), determined as (VWM = 32.8 μmol l⁻¹), was the main acidity neutralizing agent. Considering that the H⁺ ion is the only counter ion produced from the non-sea-salt fraction of the dissociated anions, the contribution of each anion to the free acidity potential has the following profile: (31.1%), (26.0%), CH₃COO⁻ (22.0%), Cl⁻ (13.7%), HCOO⁻ (5.4%) and (1.8%). The precipitation chemistry showed seasonal differences, with higher concentrations of ammonium and calcium during autumn and winter (dry period). The marine contribution was not significant, while the direct vehicular emission showed to be relevant in the ionic composition of precipitation.     

Acidification at Plastic Lake,Ontario: Has 20 Years Made a Difference?

In response to reduced sulphur emissions, there has been a large decrease in sulphate (; −0.97 μeq l⁻¹ year⁻¹) and hydrogen (−1.18 μeq l⁻¹ year⁻¹) ion concentration in bulk precipitation between 1980 and 2000 at Plastic Lake in central Ontario. The benefit of this large reduction in deposition on stream water chemistry was assessed using the gauged outflow from a conifer-forested catchment (PC1; 23.3 ha), which is influenced by a small wetland located immediately upstream of the outflow. Sulphate concentrations declined, but not significantly due to large inter-annual variation in concentration. Between 1980 and 2000, there were significant increases in dissolved organic carbon, ammonium and potassium concentration likely reflecting increased mineralisation in the wetland. Calcium concentrations in PC1 decreased during the two decade period (−2.24 μeq l⁻¹ year⁻¹), as a consequence there was no improvement in stream pH and the Ca:Al ratio in PC1 continued to decline. A similar response was noted in an upland-draining sub-catchment of PC1-08 that has been monitored since 1987. Despite large reductions in deposition and almost complete retention of nitrogen in soil, there has been no improvement (in terms of pH) in stream water at PC1 due to a combination of soil acidification and climatic (droughts, increased mineralisation) perturbations.     

Size Distribution of Inorganic Species and Their Inhaled Dose in a Detergent Industrial Workplace

Aerosol particles in the workplace of a detergent industry were sampled during July 2005 by a Berner low-pressure impactor. The samples were analyzed by atomic absorption spectrometry and ion chromatography in order to determine the size distribution of metallic elements and water-soluble inorganic ions. The size distributions of some characteristic metallic elements (Cu, Fe, Al) were unimodal with their maximum found in coarse particles. Among the water-soluble aerosol components , , Cl⁻, and Ca⁺⁺ were the major contributors to total particle mass. The lung deposition resulting from the partially hygroscopic aerosol is estimated. The calculated lung deposition reveals the impact of separate chemical aerosol compounds on the levels of the inhaled dose. The differences observed between the total and regional deposition of the different compounds appear mainly due to their different size distributions. An erratum to this article can be found at     

Can Nutrient Spiralling be Used to Detect Seasonal Nutrient Uptake in a Forested Stream?

Nutrient spiralling measurements were conducted in Lyrebird Creek, a forested stream in the Dandenong Ranges, Victoria, Australia. Spiralling indices from several nutrient (, ) enrichment experiments were correlated with seasonal variation in factors thought to control nutrient uptake, i.e., temperature, light and algal biomass. It was hypothesized that nutrient uptake would be higher in summer as increased temperatures would promote both biotic and abiotic processes and higher light levels in summer would stimulate photosynthesis. However, results did not support this hypothesis. Uptake length for and and uptake velocity were not correlated with chlorophyll-a, light or temperature (r ² < 0.30, P > 0.1) despite the seasonality of these biophysical factors (r ² > 0.42, P < 0.02). Lyrebird Creek might had no seasonal trend in nutrient uptake and/or nutrient spiraling measurements only appears suitable for contrasting streams with large differences in biophysical factors that supports biotic and abiotic nutrient processing. In addition, small errors in measuring a nutrient concentration can result in a large range in the estimated S _w and increased difficulty in determining significant differences in nutrient spiralling indices.     

Trends in Chemical Composition of Wet-only Precipitation at Rural French Monitoring Stations Over the 1990–2003 Period

The long-term monitoring of precipitation and its chemical composition are important for identifying trends in rain quality and for assessing the effectiveness of pollution control strategies. A statistical test has been used to the atmospheric concentrations measured in the French rural monitoring network (MERA) in order to bring out spatio-temporal trends in precipitation quality in France over the period 1990–2003. The non-parametric Mann–Kendall test which has been developed for detecting and estimating monotonic trends in the time series was used and applied in our study at annual values of wet-only precipitation concentrations. The emission data suggest that SO₂ and NO _x emissions decreased (−3.3 and −2.0% year⁻¹, respectively) contrary to NH₃ emissions that increased slightly (+0.2% year⁻¹) over the period 1990–2002 in France. On the national scale, the pH values have a significant decreasing trend of −0.025 ± 0.02 unit pH year⁻¹. and concentrations in precipitation have a significant decreasing trend, −3.0 ± 1.6 and −3.3 ± 0.6% year⁻¹, respectively, corresponding with the downward trends in SO₂ emissions in France (−3.3% year⁻¹). A good correlation (R ² = 0.84) between SO₂ emissions and concentrations was obtained. The decreasing trend of was more significant (−5.4 ± 5.2% year⁻¹) than that of (−1.3 ± 2.4% year⁻¹). Globally, the concentration of the major ions showed a clear downward trend including marine and alkaline ions. In addition, the relative contribution of HNO₃ to acidity precipitation increased by 51% over the studied period.     

Long-term Trends in Surface Water Quality of Five Lakes in Japan

Since 1983, the Ministry of the Environment of Japan has conducted nation-wide acid deposition surveys. To investigate the effects of acid deposition on surface water, we used the nonparametric Mann–Kendall test to find temporal trends in pH, alkalinity, and electrical conductivity (EC) in more than 10 years of data collected from five lakes and their catchments (Lake Kuttara: northernmost; Lake Kamakita: near Tokyo; Lake Ijira: central; Lake Banryu: western; and Lake Unagiike: southernmost). The pH of Lake Ijira water has declined slightly since the mid-1990s, corresponding with the downward trends seen in the pH and alkalinity of the river water flowing into the lake. There were significant upward trends in the EC of both the lake and stream water; the same trends were also found for concentrations. These trends show evidence of acidification due to atmospheric deposition, and this is the first such finding in Japan based on significant long-term trends. Lake Ijira is located about 40 km north of the Chukyo industrial area near Nagoya. The annual depositions of H⁺, nss-, and in Lake Ijira were among the highest of all deposition monitoring sites, suggesting that this is the main cause of the significant acidification observed in Lake Ijira. No significant trends suggesting acidification were observed in any of the other lake catchments in spite of the significant upward trends in EC. Upward trends in pH and alkalinity at Lake Banryu and upward trends in alkalinity at Lake Kamakita were detected, but no change in pH or alkalinity at Lake Kuttara and Lake Unagiike was observed.     

Synthesis of a block copolymer of poly(3-hydroxybutyrate) and poly(ethylene glycol) and its application to biodegradable polymer blends

A block copolymer {P[(R,S)-HB-b-EG]} of atactic poly[(R,S)-3-hydroxybutyrate] {P[(R,S)-HB]} and poly(ethylene glycol) (PEG) was prepared by the ring-opening polymerization of -butyrolactone in the presence of a macroinitiator (PEG/ZnEt₂/H₂O) which had been produced by the reaction of ,-dihydroxy PEG ( _n=3000) with ZnEt₂/H₂O (1/0.6) catalyst. The block copolymer ( _n=10,500, _w/ _n=1.2) was an A-B-A triblock copolymer comprising atactic P[(R,S)-HB] (A) and PEG (B) segments. The miscibility, physical properties, and biodegradability of binary blends of microbial poly[(R)-3-hydroxybutyrate] {P[(R)-HB]} with the block copolymer P[(R,S)-HB-b-EG] has been studied. The glass-transition temperature (T _g) data showed that the P[(R)-HB]/P[(R,S)-HB-b-EG] blend was miscible in the amorphous state. The P[(R)-HB] film became flexible and tough by means of blending with P[(R,S)-HB-b-EG] block copolymer. The enzymatic degradation of blend films was carried out at 37°C and pH 7.4 in a 0.1M phosphate solution of an extracellular PHB depolymerase fromAlcaligenes faecalis. The enzymatic degradation took place solely on the surface of the blend films.     

Modeling Acidification Recovery on Threatened Ecosystems: Application to the Evaluation of the Gothenburg Protocol in France

To evaluate the acid deposition reduction negotiated for 2010 within the UNECE LRTAP Gothenburg Protocol, sulphur and nitrogen deposition time-series (1880–2100) were compared to critical loads of acidity on five French ecosystems: Massif Central basalt (site 1) and granite (2); Paris Bassin tertiary sands (3); Vosges mountains sandstone (4) and Landes eolian sands (5). The SAFE model was used to estimate the response of soil solution pH and ratio to the deposition scenario. Among the five sites, critical loads were exceeded in the past at sites 3, 4 and 5. Sites 3 and 4 were still expected to exceed in 2010, the Protocol year. Further reduction of atmospheric deposition, mainly nitrogen, would be needed to achieve recovery on these ecosystems. At sites 3, 4 and 5, the delay between the critical load exceedance and the violation of the critical chemical criterion was estimated to be 10 to 30 years in the top soil and 50 to 90 years in the deeper soil. At site 5, a recovery was expected in the top soil in 2010 with a time lag of 10 years. Unexpectedly, soil pH continued to decrease after 1980 in the deeper soil at sites 2 and 5. This time lag indicated that acidification moved down the soil profile as a consequence of slow base cation depletion by ion exchange. This delayed response of the soil solution was the result of the combination of weathering rates and vegetation uptake but also of the relative ratio between base cation deposition and acid compounds.     

Distributions,Land-source Input and Atmospheric Fluxes of Methane in Jiaozhou Bay

CH₄ concentrations in both the surface and bottom waters of Jiaozhou Bay were determined during four surveys in 2003, which showed variability with both seasons and tidal cycles. Atmospheric fluxes of CH₄ in Jiaozhou Bay showed obvious seasonal and spatial variations, with the highest values occurring in summer and the lowest in winter. The annual emission of CH₄ from Jiaozhou Bay was estimated to be . CH₄ in the water column of Jiaozhou Bay was found to come from several land-sources including riverine water input, sewage water input and groundwater input. The spatial and temporal variation in distributions and atmospheric fluxes of CH₄ in Jiaozhou Bay was influenced mainly by the input of polluted river waters and the sewage effluents along the eastern coast, which highlights the effects of human impacts on CH₄ emission rates.     

Contribution to the Study of Fungal Attack on Some Plasticized Vinyl Formulations

The objective of this study was to develop new vinyl flooring formulations with increased resistance to fungi and microorganisms attack, by using plasticizers having a chemical composition different from that of common di-ethylhexyl phthalate (DOP). It is suspected that during the vinyl flooring life service, the attack of fungi and microorganisms leads to the degradation of DOP and the release of some volatile organic compounds (VOC). For this reason the new materials were formulated with plasticizers having chemical composition different of that of DOP i.e.: diethyleneglycol dibenzoate (2–45), tricresyl phosphate (Lindol) and phenol alkylsulphonic ester (Mesamoll). For the same reason in the new flooring formulations the vinyl polymer, vinyl chloride-vinyl acetate copolymer (VC-VAc), was partially replaced with lignin (L) a natural polymer and major component of wood and vascular plants. Besides its other functions in wood, L imparts resistance to the most microorganisms attack. An organosolv lignin Alcell lignin (AL) was utilized as partial replacement of VC-VAc copolymer.The influence of the new plasticizers, as well as the influence of the partial replacement of VC-VAc copolymer with L on the resistance of the new formulations to fungal attack was evaluated following a standard procedure given in ASTM G 21–2002 “Determining Resistance of Synthetic Polymeric Materials to Fungi”. The evaluation has been undertaken for controls (formulated without AL) and blends (formulated with 20 parts AL) specimens. Test specimens were inoculated with a mixture of five fungi. Following 28 days of incubation at 28°C and 95% relative humidity, the specimens were examinated visual and under the microscope and rated for fungal growth. Weight loss, changes in mechanical properties and changes in glass transition temperature due to the effect of biodeterioration were also determined.Although each plasticizer has a specific resistance to hydrolysis due to differences among ester groups, the visible effects of fungal attack, in formulations without AL, is similar for all plasticized controls, with the exception of formulations incorporating diethyleneglycol dibenzoate (2–45) in which a higher degree of biodegradation was always present. Based on the weight loss of specimens formulated without AL, their resistance to fungal attack can be rated as follows: . The same rating is applicable for blend specimens. The results have demonstrated that each particular AL-plasticizer-additives formulation has its specific mechanism of biodegradation.     

Photo-/Bio-degradability of Agro Waste and Ethylene–Propylene Copolymers Composites Under Abiotic and Biotic Environments

Composites were prepared by two methods, (i) graft copolymerization (GFC) of isotactic polypropylene (PP) with maliec anhydride, (MAH) followed by esterification with coir fiber and (ii) by direct reactive mixing (DFC) of polypropylene (PP) and ethylene–propylene (EP) copolymers with MAH and peroxide with coir fiber. These composites, after molding in films (5×5 cm, m thickness) were examined for susceptibility to biological attack by measuring the percentage weight loss in compost upto 6 months, periodically, and fungal colonization on surface of the samples, when kept as sole carbon source for the growth of Aspergillus niger in culture medium upto 40 days. Photodegradation was evaluated by monitoring the variations in FT-IR spectrum and crack formation after successive treatment with UV light (≥290 nm) for 0, 20, 50 and 100 h at 60°C in the presence of air. Specimens of virgin PP were taken as a reference during all period of photo and biodegradation studies. Significant changes were observed depending on the preparation methods during photodegradation and biodisintegration of composites. DFCs samples were disintegrated faster than GFCs during the composting whereas, in culture, GFCs were covered highly in well uniform way by fungi. It was observed that photo-oxidative ageing directly enhanced the biodegradability of composites as the increase in fungal growth rate and decrease in weight during composting were found. It was concluded that extent of compatibilization had a profound effect on photo-oxidation and biodisintegration of composite material; consequently ester bonds were main units during fungal consumption. Composition of monomers in copolymers was also showing significant effect on the degradability which decreased with increasing content of ethylene in ethylene–propylene (EP) copolymers.     

Modelling Phosphorus Retention in Lakes and Reservoirs

Steady-state models for the prediction of P retention coefficient (R) in lakes were evaluated using data from 93 natural lakes and 119 reservoirs situated in the temperate zone. Most of the already existing models predicted R relatively successfully in lakes while it was seriously under-estimated in reservoirs. A statistical analysis indicated the main causes of differences in R between lakes and reservoirs: (a) distinct relationships between P sedimentation coefficient, depth, and water residence time; (b) existence of significant inflow–outflow P concentration gradients in reservoirs. Two new models of different complexity were developed for estimating R in reservoirs: , where τ is water residence time (year), was derived from the Vollenweider/Larsen and Mercier model by adding a calibrated parameter accounting for spatial P non-homogeneity in the water body, and is applicable for reservoirs but not lakes, and , where [P_in] is volume-weighted P concentration in all inputs to the water body (μg l⁻¹), was obtained by re-calibrating the OECD general equation, and is generally applicable for both lakes and reservoirs. These optimised models yield unbiased estimates over a large range of reservoir types.     

Assessing Aerobic Biodegradability of Plastics in Aqueous Environment by GC-Analyzing Composition of Equilibrium Gaseous Phase

Testing biodegradability of plastics under varied conditions of the environment as well as under laboratory conditions in accordance with valid international standards is very laborious, lengthy and often also economically demanding. For this reason, applicability was verified of gas chromatography to analyze gaseous phase when investigating the biodegradation course of plastics in an aqueous environment as an alternative to customary employed methods. A mathematical model of acid–basic CO₂ equilibrium in a gas–liquid system was worked out, enabling to determine quantity of produced CO₂ through chromatographic analysis of gaseous phase, in dependence on ratio of liquid and gas phase volumes (V _l/V _g) and on actual pH of liquid phase. Experimental conditions for organizing the tests were optimized. A ratio that proved suitable was V _l/V _g ≅ 0.1 at pH ≈ 7.1 of liquid phase. Under these test conditions, biodegradability of model samples, PHB, Gellan gum and Xanthan gum, was explored; course of biodegradation was studied through produced CO₂ (values ) determined by analyzing gaseous phase through gas chromatography on the one hand, and through customary “titration” procedure on the other. With water-soluble polymers, the decrement in dissolved organic carbon (values D _DOC) was also studied. Difference between values does not exceed 5%. The procedures in question are alternative “substituting” procedures for observing course of aerobic biodegradation of substances in an aqueous environment.     

Molecular Weight Changes and Polymeric Matrix Changes Correlated with the Formation of Degradation Products in Biodegraded Polyethylene

The molecular weight changes in abiotically and biotically degraded LDPE and LDPE modified with starch and/or prooxidant were compared with the formation of degradation products. The samples were thermooxidized for 6 days at 100°C to initiate degradation and then either inoculated with Arthobacter paraffineus or kept sterile. After 3.5 years homologous series of mono- and dicarboxylic acids and ketoacids were identified by GC-MS in abiotic samples, while complete disappearance of these acids was observed in biotic environments. The molecular weights of the biotically aged samples were slightly higher than the molecular weights of the corresponding abiotically aged samples, which is exemplified by the increase in from 5200 g/mol for a sterile sample with the highest amount of prooxidant to 6000 g/mol for the corresponding biodegraded sample. The higher molecular weight in the biotic environment is explained by the assimilation of carboxylic acids and low molecular weight polyethylene chains by microorganisms. Assimilation of the low molecular weight products is further confirmed by the absence of carboxylic acids in the biotic samples. Fewer carbonyls and more double bonds were seen by FTIR in the biodegraded samples, which is in agreement with the biodegradation mechanism of polyethylene.     

Influences of chemical activators on incinerator bottom ash

This research has applied different chemical activators to mechanically and thermally treated fine fraction (<14 mm) of incinerator bottom ash (IBA), in order to investigate the influences of chemical activators on this new pozzolanic material. IBA has been milled and thermally treated at 800 degrees C (TIBA). The TIBA produced was blended with Ca(OH)(2) and evaluated for setting time, reactivity and compressive strength after the addition of 0.0565 mole of Na(2)SO(4), K(2)SO(4), Na(2)CO(3), K(2)CO(3), NaOH, KOH and CaCl(2) into 100g of binder (TIBA+Ca(OH)(2)). The microstructures of activated IBA and hydrated samples have been characterized by X-ray diffraction (XRD) and thermogravimetry (TG) analysis. Thermal treatment is found to produce gehlenite (Ca(2)Al(2)SiO(7)), wollastonite (CaSiO(3)) and mayenite (Ca(12)Al(14)O(33)) phases. The thermally treated IBA samples are significantly more reactive than the milled IBA. The addition of Na(2)CO(3) can increase the compressive strength and calcium hydroxide consumption at 28-day curing ages. However, the addition of Na(2)SO(4), K(2)SO(4), K(2)CO(3), NaOH and KOH reduces the strength and hydration reaction. Moreover, these chemicals produce more porous samples due to increased generation of hydrogen gas. The addition of CaCl(2) has a negative effect on the hydration of TIBA samples. Calcium aluminium oxide carbonate sulphide hydrate (Ca(4)Al(2)O(6)(CO(3))(0.67)(SO(3))(0.33)(H(2)O)(11)) is the main hydration product in the samples with activated IBA, except for the sample containing CaCl(2).     

Enhanced methane production from ultrasound pre-treated and hygienized dairy cattle slurry

The effect of hygienization (70 °C, 60 min) and ultrasound (6000 ± 500 kJ/kg total solids (TS)) pre-treatments on hydrolysis and biological methane (CH(4)) potential (BMP) of dairy cattle slurry was studied. The BMP of the untreated slurry (control) was 210 ± 10 Nm(3) CH(4)/ton volatile solids (VS) added; after ultrasound pre-treatment it was 250 ± 10 Nm(3) CH(4)/ton VS(added) and after hygienization 280 ± 20 Nm(3) CH(4)/ton VS(added). The specific methanogenic activity (SMA) of the inoculum increased from 22 (untreated) to 26 (ultrasound treated) and up to 28 N ml CH(4)/g VS d, after hygienization. However, only hygienization achieved a positive net energy balance. Both pre-treatments increased the VS-based hydrolysis of slurry (10-96%), soluble nitrogen (N(sol)) content in digestates (20 ± 5%) and biodegradability of the slurry (8 ± 3%) as estimated via elevated VS removal.     

Analysis of methanogenic activity in a thermophilic-dry anaerobic reactor: use of fluorescent in situ hybridization

Methanogenic activity in a thermophilic-dry anaerobic reactor was determined by comparing the amount of methane generated for each of the organic loading rates with the size of the total and specific methanogenic population, as determined by fluorescent in situ hybridization. A high correlation was evident between the total methanogenic activity and retention time [-0.6988Ln(x)+2.667] (R(2) 0.8866). The total methanogenic activity increased from 0.04x10(-8) mLCH(4) cell(-1)day(-1) to 0.38x10(-8) mLCH(4) cell(-1)day(-1) while the retention time decreased, augmenting the organic loading rates. The specific methanogenic activities of H(2)-utilizing methanogens and acetate-utilizing methanogens increased until they stabilised at 0.64x10(-8) mLCH(4) cell(-1)day(-1) and 0.33x10(-8) mLCH(4) cell(-1)day(-1), respectively. The methanogenic activity of H(2)-utilizing methanogens was higher than acetate-utilizing methanogens, indicating that maintaining a low partial pressure of hydrogen does not inhibit the acetoclastic methanogenesis or the anaerobic process.     

Case study: Conducting an accelerated cleanup at a superfund site in a mixed residential and industrial area

This article presents a case study of an accelerated cleanup conducted by EPA at the Adams Plating Company (APC) Superfund site near Lansing, Michigan. The APC site remediation was a Superfund EPA-lead project under the remedial program in Region 5. An accelerated cleanup was possible at the APC site by consistently identifying, evaluating, and implementing opportunities to streamline the remedial investigation (RI) and remedial design (RD) process. Streamlining opportunities were discovered and implemented in both the technical and administrative aspects of the project. Streamlining components used to accelerate the remedial process included: (1) extensive use of field screening techniques during the Phase II RI; (2) a focused feasibility study (FS) that evaluated only practical alternatives; (3) maintaining project momentum by initiating the RD concurrent with the issuance of the Record of Decision (ROD); (4) a highly accelerated RD with limited predesign work; (5) elimination of the transition period between RD and remedial action (RA) project phases; (6) frequent and effective communication, coordination, and cooperation between all parties involved (EPA, Michigan Department of Natural Resources (MDNR), technical contractor, PRC Environmental Management, Inc. (PRC), and the public); (7) maintaining a consistent project team throughout project duration; and (8) the setting of aggressive project goals.