bluuebunny/crossref_metadata_2025 huggingface dataset:
Pollution sources identification in the “land-sea” system
Authors: Dachev D. , Zlatanova S.
Published: May 2018

It is our opinon that the new scientific thinking and education in the 21st century will increase the significance of the multidisciplinary nature knowledge. The nature of the marine sediments as well as the biochemical features of the littoral organisms appear to be in close relation to the geochemical impact of the coastal onshore. The biogeochemical analysis of the terrestrial and marine biocenosis is still fragmental, without balance between the casual and sequential relationships. Along the Bulgarian Black Sea coast the latter necessitates the geological pattern clarification of the areas south of Bourgas. Even a superficial overview of the geological features of the region highlights the impact of the geochemical anomalies related to Rosen and Zidarovo volcanic apparatuses and intrusions, other ore deposits south and south-west as well. However, the intensive anthropogenic impact on the geochemical haloes should be pointed out in the complex of ecological damage to the coast. Through complementary geoecological studies a significant updating of the knowledge is suggested. The geoecological mapping is needed to present the ratio of the lands saturated with geonoxes, and anthropogenically polluted ones. The new methodology recommended was applied to make the distinction of such lands in the regions of Pirdop and Kardjali. Another key element appears to be the ecologicalÐeconomic characteristics in the offshore-onshore balance. The marine resources will be studied in the alternative context: benefit-damage from the onshore polluters, and the biogeochemical characteristics of the littoral zone. The coastal areas environmental status should make a distinction between the environmentally undamaged, environmentally damaged by nature, anthropogenically damaged and complex damaged lands. Each ecological study or analysis presenting the ecological condition of the environment in a status quo (at a certain moment and at a certain location) is described in this work as a Status Geoecological System. For environmental management and protection of the Black Sea we refer to an indispensable Data File representing the Dynamic Geoecological System.
Design of SBR systems for nutrient removal from wastewaters subject to seasonal fluctuations
Authors: Artan N. , Orhon D. , Tasli R.
Published: May 2018

Designing SBR systems for simultaneous biological nitrogen and phosphorus removal is evaluated and defined for wastewaters from small coastal areas subject to seasonal fluctuations in quantity and quality. A design procedure is developed using basic process stoichiometry and significant operating parameters. A stepwise approach was utilized to secure full nitrification, available nitrate limitation for denitrification, a mixed phase with enough anaerobic fraction for P removal. A fundamental relationship between the effective sludge age, the recycle ratio and the cycle time was developed and used for the determination of physical design parameters.
Phosphorus reductions following riparian restoration in two agricultural watersheds in Vermont, USA
Authors: Meals D.W. , Hopkins R.B.
Published: May 2018

Achievement of management goals for Lake Champlain (Vermont/New York, USA and Quebec, Canada) will require significant reductions of phosphorus (P) loads from agriculture, the dominant diffuse source in the basin. Cost-effective P reduction strategies must be based on reliable treatment techniques beyond basic erosion control and animal waste storage practices. The Lake Champlain Basin Agricultural Watersheds National Monitoring Program (NMP) Project evaluates the effectiveness of low-cost livestock exclusion, streambank protection, and riparian restoration practices in reducing concentrations and loads of diffuse-source pollutants from grazing land at the watershed level. Treatment and control watersheds in northwestern Vermont have been monitored since 1994 according to a paired-watershed design. Monitoring includes continuous stream discharge recording, flow-proportional sampling for total P and other pollutants, and documentation of land use and agricultural management activities. Strong statistical calibration between the control and treatment watersheds has been achieved. Landowner participation in the land treatment program was entirely voluntary and all treatments were 100% cost-shared by the project and cooperators. Installation of riparian fencing, alternative water supplies, protected stream crossings, and streambank bioengineering was completed in 1997 at a cost of less than US$40,000. The paired-watershed design was effective in controlling for the influence of extreme variations in precipitation and streamflow over six years of monitoring. Two years of post-treatment data have documented significant reductions in P concentrations and loads from both treated watersheds. Reductions of ∼20% in mean total P concentration and ∼20–50% in mean total P load have been observed, with greater reductions occurring in the watershed receiving more extensive treatment. The effectiveness of riparian zone restoration in P reduction tended to be lower during periods of very high runoff, especially outside the growing season.
Potential toxicity of pesticides measured in midwestern streams to aquatic organisms
Authors: Battaglin W. , Fairchild J.
Published: May 2018

Society is becoming increasingly aware of the value of healthy aquatic ecosystems as well as the effects that man’s activities have on those ecosystems. In recent years, many urban and industrial sources of contamination have been reduced or eliminated. The agricultural community also has worked towards reducing off-site movement of agricultural chemicals, but their use in farming is still growing. A small fraction, estimated at <1 to 2% of the pesticides applied to crops are lost from fields and enter nearby streams during rainfall events. In many cases aquatic organisms are exposed to mixtures of chemicals, which may lead to greater non-target risk than that predicted based on traditional risk assessments for single chemicals. We evaluated the potential toxicity of environmental mixtures of 5 classes of pesticides using concentrations from water samples collected from ∼50 sites on midwestern streams during late spring or early summer runoff events in 1989 and 1998. Toxicity index values are calculated as the concentration of the compound in the sample divided by the EC50 or LC50 of an aquatic organism. These index values are summed within a pesticide class and for all classes to determine additive pesticide class and total pesticide toxicity indices. Toxicity index values greater than 1.0 indicate probable toxicity of a class of pesticides measured in a water sample to aquatic organisms. Results indicate that some samples had probable toxicity to duckweed and green algae, but few are suspected of having significant toxicity to bluegill sunfish or chorus frogs.
Comparative study on microbial removal in immersed membrane filtration (IMF) with and without powdered activated carbon (PAC)
Authors: Ujang Z. , Au Y.L. , Nagaoka H.
Published: May 2018

This paper describes an investigation on the effect of microbial removal using IMF for high quality drinking water production. The comparison of IMF and IMF-PAC configuration was carried out in the study to highlight the importance of PAC in the system. The specific objective of this study was to study the effect of PAC adsorption in the IMF-PAC system particularly in removing microbial substances from contaminated raw water. A bench scale IMF-PAC configuration using a flat sheet microfiltration membrane was set up for experimental purposes. Experimentally, the result has shown high removal of microbial substances with the IMF-PAC system compared to IMF. The result of E.coli removal achieved was below the detectable level due to the microbial size, which is bigger than membrane pore size. The addition of PAC has shown a direct effect on total microbial removal. The adsorption of microbial onto PAC surfaces reduced the amount of smaller microbial present in permeate samples. As a conclusion, the configuration of IMF is a promising separation process in removing microbial substances, especially when the system is combined with PAC.
Model studies on granular activated carbon adsorption in fixed bed filtration
Authors: Jusoh A.B. , Noor M.J.M.M. , Piow S.B.
Published: May 2018

The removal of natural organic matter (NOM) using a continuous flow fixed bed granular activated carbon (GAC) column was studied and the results were then fitted with the AdamsÐBohart, Bed-Depth-Service-Time and Clarks models. The GAC, KI-6070 and KI-8085 used in the study had external surface areas of 277 m2/g and 547 m2/g, respectively. Adsorption of NOM by the GAC was complex and involved more than one rate-limiting step. The critical bed depths for KI-6070 and KI-8085 were 0.24 m and 0.3 m, respectively. The Clark model was more effective in simulating the absorbent breakthrough process as compared to the AdamsÐBohart model. The lower empty bed contact time (EBCT) i.e. 15 minutes gave a better fit to the Clark Model as compared to EBCT of 20 and 30 minutes.
Predicting pesticide concentrations in river water with a hydrologically calibrated basin-scale runoff model
Authors: Matsui Y. , Itoshiro S. , Buma M. , Matsushita T. , Hosogoe K. , Yuasa A. , Shinoda S. , Inoue T.
Published: May 2018

Hydrological diffuse pollution models require calibration before they can be used to make accurate long-term predictions for a range of hydrological and meteorological conditions. As such, the applicability of the models to the dispersion of new pesticides is limited due to the lack of calibration data. In this study, the performance of a GIS-based basin-scale runoff model for predicting the concentrations of paddy-farming pesticides in river water was examined when calibrated using hydrological data alone, without optimization based on empirical pesticide concentration data. The prediction accuracy on a daily or hourly scale was somewhat unsatisfactory due to inevitable compromises concerning rice farming schedules. However, the month-averaged pesticide concentrations were satisfactorily accurate; more than 50% of predicted values were between half and twice the observed values, considering the deficiencies of the input data, particularly for pesticide usage, which may include up to 50% error.
Search for the northwest passage: the assignation of NSP (non-point source pollution) rights in nutrient trading programs
Authors: Collentine D.
Published: May 2018

The search for solutions to the problem of non-point source pollution (NSP) includes alternatives based on theories associated with the use of tradable pollution permits. Tradable permit programs have received significant support as a promising policy for the reduction of effluent discharges but programs in practice have not been regarded as successful. The lack of success is ascribed to the design of the programs. However, this may be a design problem which is insurmountable due to the nature of the NSP problem. Tradable permit solutions are based on an assumption that the assignation of quantifiable rights to both point and nonpoint sources, based on some predetermined ambient water quality measure, is possible. The conclusion here is that there are significant features particular to NSP that hinder the introduction of rights and significantly decrease the utility of tradable permit solutions.
Arsenic removal efficiency and mechanisms by electro-chemical precipitation process
Authors: Pinisakul A. , Polprasert C. , Parkpian P. , Satayavivad J.
Published: May 2018

This research was conducted to investigate the efficiency and mechanisms of arsenic (As) removal from a contaminated water by using the electro-chemical precipitation (ECP) process, with the operating conditions as follows: initial As concentration of 0.5-5 mg/L, 0.1 M KCl, electrical gradient of 200 V/m and initial pH higher than 3. The laboratory-scale ECP unit was able to reduce As to within the WHO drinking water standard of 0.01 mg/L in 20 min. The ClÐ salt was found to yield better As removal efficiencies than the NO3− salt probably because NO3− ions interfered with the production of OH− and Fe(OH)3, important for As removal. X-ray fluorescence and X-ray diffractometric analysis revealed maghemite (Fe2O3) and angelellite (Fe4As2O11) to be the major compounds present in the precipitated sludge. The percent Fe2O3 and Fe4As2O11 contents of the dried ECP sludge were 98.29% and 0.26%, respectively. From a mass balance analysis, As removal in the ECP process was due to: incorporation in and adsorption on the ECP sludge - 64.9-94.9%, conversion to arsine (AsH3) gas - 10.5-15.6%, adsorption on the electrode plates and reactor walls - 0.03-1.1%, residual in the supernatant - 0.2-0.4%, and unaccounted for - 1.2-19.8%.
Pilot-scale study of an anaerobic baffled reactor for the treatment of domestic wastewater
Authors: Dama P. , Bell J. , Foxon K.M. , Brouckaert C.J. , Huang T. , Buckley C.A. , Naidoo V. , Stuckey D.
Published: May 2018

Large proportions of South Africans live in areas with inadequate sanitation and a poor infrastructure for waterborne sanitation. Service providers are looking for alternative wastewater treatment options. The anaerobic baffled reactor is being considered as a decentralised sanitation option in these areas. A 3,200 L reactor was built and is currently being evaluated at a wastewater treatment works. The reactor was built based on experiences gained from working with a laboratory reactor (10 L) and predicted flow patterns observed on a computational fluid dynamics model. The design and construction of the reactor will be discussed in this paper. The feed to the reactor consists of screen degritted sewage and the flow to the reactor is maintained by means of a programmable logic controller. The pilot-plant layout is discussed in this paper. Samples are analysed for chemical oxygen demand, pH, alkalinity, ammonia, phosphorus, solids and ash content. Reductions of between 70 and 80% are obtained for COD and the pH values for the effluent samples are within the discharge limits.
Evaluation of land use/land cover datasets for urban watershed modeling
Authors: Burian S.J. , Brown M.J. , McPherson T.N.
Published: May 2018

Land use/land cover (LULC) data are a vital component for nonpoint source pollution modeling. Most watershed hydrology and pollutant loading models use, in some capacity, LULC information to generate runoff and pollutant loading estimates. Simple equation methods predict runoff and pollutant loads using runoff coefficients or pollutant export coefficients that are often correlated to LULC type. Complex models use input variables and parameters to represent watershed characteristics and pollutant buildup and washoff rates as a function of LULC type. Whether using simple or complex models an accurate LULC dataset with an appropriate spatial resolution and level of detail is paramount for reliable predictions. The study presented in this paper compared and evaluated several LULC dataset sources for application in urban environmental modeling. The commonly used USGS LULC datasets have coarser spatial resolution and lower levels of classification than other LULC datasets. In addition, the USGS datasets do not accurately represent the land use in areas that have undergone significant land use change during the past two decades. We performed a watershed modeling analysis of three urban catchments in Los Angeles, California, USA to investigate the relative difference in average annual runoff volumes and total suspended solids (TSS) loads when using the USGS LULC dataset versus using a more detailed and current LULC dataset. When the two LULC datasets were aggregated to the same land use categories, the relative differences in predicted average annual runoff volumes and TSS loads from the three catchments were 8 to 14% and 13 to 40%, respectively. The relative differences did not have a predictable relationship with catchment size.
Struvite precipitation from anaerobically treated municipal and landfill wastewaters
Authors: Altinbaş M. , Yangin C. , Ozturk I.
Published: May 2018

A two-stage treatment system including upflow anaerobic sludge blanket reactor pre-treatment combined with a chemical post treatment system such as magnesium ammonium phosphate (MAP) precipitation was proposed as a comparable alternative to conventional biological treatment. In this study, anaerobically pre-treated domestic wastewater, domestic wastewater mixed with 2% and 3% of leachate by volume and raw leachate were further treated chemically with MAP precipitation. MAP precipitation was both applied at the stoichiometric ratio (Mg:NH4 = PO4; 1:1:1) and above the stoichiometric ratio (1.1:1:1 and 1.1:1:1.1) on domestic wastewater +3% leachate mixture. Maximum NH4-N removal of 68% was achieved at the pH of 9.2 at the stoichiometric ratio, whereas at the same pH value 70 to 72% NH4-N removal was obtained above the stoichiometric ratio. Additional ammonia recovery studies were conducted on Fenton's oxidation applied effluents before MAP precipitation and no significant additional ammonium removal was achieved. However, by the application of Fenton's oxidation high additional COD removals were obtained. Consequently, chemical treatment by MAP precipitation and/or Fenton's oxidation after anaerobic treatment yielded very effective removals for COD and NH4-N in domestic wastewaters + leachate mixtures.
Advanced treatment of high strength opium alkaloid industry effluents
Authors: Aydin A.F. , Altinbas M. , Sevimli M.F. , Ozturk I. , Sarikaya H.Z.
Published: May 2018

The purpose of this study was to investigate an effective treatment system which can be applicable to treat opium alkaloid industry (OAI) effluents characterised with high COD, TKN, dark color and non-biodegradable organic pollutants. In the first phase of the study, lab-scale anaerobic (UASBR) + aerobic (SBR) treatability studies were carried out on opium processing industry effluents. Effluent CODs from the two staged biological treatment system were relatively high (∼700 mgl−1) and additional post treatment was required. Physico-chemical treatability studies previously carried out on the effluent of opium alkaloid wastewater treatment plant, were not effective in removing residual COD and color. In the second phase of the study, the refractory organics causing higher inert COD values in the SBR effluent were additionally treated by using Fenton's Oxidation. The batch tests were performed to determine the optimum operating conditions including pH, H2O2 dosage, molar ratio of Fe2+/H2O2 and reaction time. It was found that removal efficiencies of COD and color for 30 minutes reaction time were about 90% and 95%, respectively. The ratio of H2O2/FeSO4 was determined as 200 mgl−1/600 mgl−1 for the optimum oxidation and coagulation process at pH 4. Experimental results of the present study have clearly indicated that the Fenton's oxidation technology is capable to treat almost all parts of the organics which consist of both soluble initial and microbial inert fractions of COD for opium alkaloid industry effluents. Effluents from the Fenton's Oxidation process can satisfy effluent standards for COD and color in general.
Strategies for augmenting the pentachlorophenol degradation potential of UASB anaerobic granules
Authors: Guiot S.R. , Tartakovsky B. , Lanthier M. , Lévesque M.-J. , Manuel M.F. , Beaudet R. , Greer C.W. , Villemur R.
Published: May 2018

Anaerobic degradation of pentachlorophenol (PCP) is an example of a process that may benefit from enrichment or bioaugmentation. In one approach, enrichment acceleration was attempted by applying an on-line control-based selective stress strategy to a native anaerobic upflow sludge bed (UASB) system; this strategy linked PCP loading rate to methane production. As a result, the reactor biomass potential for PCP complete dechlorination reached a rate of 4 mg g−1 volatile suspended solid (VSS) day−1 within a period of 120 days. In another approach, a pure culture, Desulfitobacterium frappieri PCP-1, a strictly anaerobic Gram-positive bacterium, was used to augment the granular biomass of the UASB reactor. This also resulted in a specific degradation rate of 4 mg PCP g−1 VSS day−1; however, this potential was attained within 56 days. Fluorescent in situ hybridization (FISH) showed that the PCP-1 strain was able to rapidly attach to the granule and densely colonize the outer biofilm layer.
Microbial cycling of volatile organic sulfur compounds in anoxic environments
Authors: Lomans B.P. , Pol A. , Op den Camp H.J.M.
Published: May 2018

Microbial cycling of volatile organic sulfur compounds (VOSC) is investigated due to the impact these compounds are thought to have on environmental processes like global temperature control, acid precipitation and the global sulfur cycle. Moreover, in several kinds of industries like composting plants and the paper industry VOSC are released causing odor problems. Waste streams containing these compounds must be treated in order to avoid the release of these compounds to the atmosphere. This paper describes the general mechanisms for the production and degradation of methanethiol (MT) and dimethyl sulfide (DMS), two ubiquitous VOSC in anaerobic environments. Slurry incubations indicated that methylation of sulfide and MT resulting in MT and DMS, respectively, is one of the major mechanisms for VOSC in sulfide-rich anaerobic environments. An anaerobic bacterium that is responsible for the formation of MT and DMS through the anaerobic methylation of H2S and MT was isolated from a freshwater pond after enrichment with syringate as a methyl group donating compound and sole carbon source.

In spite of the continuous formation of MT and DMS, steady state concentrations are generally very low. This is due to the microbial degradation of these compounds. Experiments with sulfate-rich and sulfate-amended sediment slurries demonstrated that besides methanogens, sulfate-reducing bacteria can also degrade MT and DMS, provided that sulfate is available. A methanogen was isolated that is able to grow on DMS as the sole carbon source. A large survey of sediments slurries of various origin demonstrated that both isolates are commonly occurring inhabitants of anaerobic environments.
Use of lysis and recycle to control excess sludge production in activated sludge treatment: bench scale study and effect of chlorinated organic compounds
Authors: Nolasco M.A. , Campos A.L.O. , Springer A.M. , Pires E.C.
Published: May 2018

The most widely used treatment system in the pulp and paper industry - the activated sludge - produces high quantities of sludge which need proper disposal. In this paper a modified activated sludge process is presented. A synthetic wastewater, prepared to simulate the effluent of bleached and unbleached pulp and paper plant wastewater, was submitted to treatment in a bench scale aerobic reactor. The excess sludge was lysed in a mechanical mill - Kaddy™ mill - and totally recycled to the aeration tank. In the first phase the synthetic wastewater, without the chlorinated compounds, was fed to the reactor. In the second phase increasing dosages of the chlorinated compounds were used. Total recycle of excess sludge after disintegration did not produce adverse effects. During the first phase average COD removal efficiency was 65% for the control unit, which operated in a conventional way, and 63% for the treatment unit, which operated with total recycle. During the second phase the COD removal efficiency increased to 77% in the control unit and 75% in the treatment unit. Chlorinated organics removal was 85% in the treatment unit and 86% for the control unit. These differences are not significant.
Modelling the competition between sulphate reducers and methanogens in a thermophilic methanol-fed bioreactor
Authors: Spanjers H. , Weijma J. , Abusam A.
Published: May 2018

Sulphate can be removed from wastewater by means of biological anaerobic reduction to sulphide. The reduction requires the presence of a substrate that can serve as an electron donor. Methanol is a suitable electron donor for sulphate reduction under thermophilic conditions. In an anaerobic system containing methanol and sulphate, acetogenic bacteria (AB) and methanogenic archaea (MA) compete with sulphate reducing bacteria (SRB) for methanol or its degradation intermediates. Previously obtained results indicate that at 65°C SRB and MA mainly compete for the intermediate hydrogen instead of methanol. For efficient use of methanol as electron donor for sulphate reduction it is important that for the treatment of sulphate wastewater in an anaerobic reactor SRB out-compete MA. The mechanisms that determine the outcome of the competition are, however, not well understood. This paper describes a model based on growth kinetics of methanol-oxidising AB, and hydrogen-consuming SRB and MA, that can describe the competition between SRB and MA in a methanol-fed bioreactor. We present the model and its calibration using experimental data, and we discuss its shortcomings and suggest possible improvements.
Key parameters in sludge dewatering: testing for the shear sensitivity and EPS content
Authors: Mikkelsen L.H. , Mascarenhas T. , Nielsen P.H.
Published: May 2018

The fraction of extractable extracellular polymeric substances (EPS) and the shear sensitivity (kSS) are key parameters with respect to sludge dewatering, affecting the dry matter content of dewatered sludge and the dewatering rate and conditioner demand, respectively. Methods are described for determination of the two key parameters by use of the same laboratory test reactor. The implications of such characterisation with respect to dewatering are discussed based on examples of application to sludge processing and novel process development for sludge minimisation.
Polymer conditioning of alum sludge and discrepancies between estimates of the optimum dosage
Authors: Zhao Y.Q. , Papavasilopoulos E.N. , Bache D.H. , Mackinnon P.A.
Published: May 2018

The paper outlines the effects of polymer conditioning on alum sludge properties, such as floc size, density, fractal dimension (DF) and rheological properties. Experimental results demonstrate that polymer conditioning of alum sludge leads to: larger floc size with a plateau reached in higher doses; higher densities associated with higher doses; increased degree of compactness; and an initial decrease followed by an increase of supernatant viscosity with continued increase in polymer dose. The secondary focus of this paper dwells on a comparison of the estimates of optimum dose using different criteria that emanate from established dewatering tests such as CST, SRF, liquid phase viscosity and modified SRF as well as a simple settlement test in terms of CML30. Alum sludge was derived from a water works treating coloured, low-turbidity raw waters.
On-line measurements of COD, TOC, VFA, total and partial alkalinity in anaerobic digestion processes using infra-red spectrometry
Authors: Steyer J.P. , Bouvier J.C. , Conte T. , Gras P. , Harmand J. , Delgenes J.P.
Published: May 2018

This paper describes the use of a Fourier Transform Infra-Red (FT-IR) spectrometer as an on-line sensor to measure Chemical Oxygen Demand (COD), Total Organic Carbon (TOC), Volatile Fatty Acids (VFA), and Partial and Total Alkalinity (PA and TA) in anaerobic digestion processes for the treatment of industrial wastewaters. Comparison with manual off-line analysis and with an on-line industrial TOC analyser and an on-line titrimetric sensor (for the measurements of VFA, TA and PA) are provided to demonstrate the interest of spectral analysis in the mid infra-red domain for the monitoring of anaerobic digestion processes. In order to further illustrate the advantages of using such a technique, on-line measurements recorded during an accident of the pH regulation in the input (pH in the reactor went above 11 and biomass activity stopped) are shown. They demonstrate that, if carefully performed, the calibration can be extended outside its range while being still compatible with requirements of wastewater treatment processes.
Volatile organic compound emissions during the composting of biosolids from a domestic wastewater treatment plant
Authors: Ramos C.X. , Estévez S.L. , Giraldo E.
Published: May 2018

VOCs emitted by two composting static piles of biosolids coming from the “El Salitre” wastewater treatment plant (Bogotá, Colombia) were analysed during the composting process. Each pile in its sampling time was maintained with a different aeration system. The sampling was made using Solid Phase Microextraction (SPME); separation and identifications were made using Gas Chromatography (GC) coupled to Mass Spectrometry (MS). Aliphatic and aromatic hydrocarbons, chlorinated compounds, ketones, mercaptans, alcohols and amines were identified in concentrations greater than the norms stipulated by the EPA for inhalation in humans beings. The emission behavior varied according to the aeration system used.
Impact on crops, plants and soils of metal trace elements transfer and flux, after spreading of fertilizers and biosolids
Authors: Maisonnave V. , Montréjaud-Vignoles M. , Bonnin C. , Revel J.-C.
Published: May 2018

In France, the yearly production of sludge from wastewater treatment plants is 900,000 metric tons dry matter and 60% of this is reused for land application. Today, the sustainability of this pathway is open to question. Among the different arguments cited are the levels of metal trace elements and the risks of accumulation in soils. With the ultimate aim of agronomic sludge recycling, the transfer of metal trace elements has been studied using vegetation containers planted with rye-grass under controlled conditions of temperature and humidity. Samples of a domestic sludge, an industrial sludge and a fertilizer have been mixed with the soil. By monitoring the growth of the rye-grass, we have been able to observe that the addition of sludge increases production of plant matter. It appears that the roots absorb higher quantities of metal trace elements and form a barrier to their transfer to the above ground parts of the rye-grass. For the group of metal trace elements studied, no significant differences have been observed between the rye-grass grown on soil alone and that on soils amended with fertilizer or urban sludge. For the majority of the vegetation containers studied, there has been no significant modification in the soil metal distribution over time, as a result of the addition of urban sludge, and no significant difference between fertilizers and sludges.
Simultaneous production of biopesticide and alkaline proteases by Bacillus thuringiensis using sewage sludge as a raw material
Authors: Tyagi R.D. , Sikati Foko V. , Barnabe S. , Vidyarthi A.S. , Valéro J.R. , Surampalli R.Y.
Published: May 2018

The simultaneous production of Bacillus thuringiensis (Bt) based biopesticide and proteases was studied using synthetic medium and wastewater sludge as a raw material. The studies were conducted in shake flask and computer controlled 15-L capacity fermentors. Measuring viable cell and spore counts, entomotoxicity and protease activity monitored the progress of the biopesticide production process. A higher viable cell count and spore count was observed in synthetic Soya medium, however, higher entomotoxicity and protease activity were observed in wastewater sludge medium. Thus, the wastewater sludge is a better raw material than commercial Soya medium for the biopesticides and enzyme production. The maximum entomotoxicity and protease activity observed in the fermentor was 9,332 IU/μL and 4.58 IU/mL, respectively. The proteases produced by Bt were also characterised. Two types of proteases were detected; neutral proteases with pH optimum 7.0 and alkaline proteases with pH optimum 10-11. Further, two types of alkaline proteases were detected; one having a pH and temperature optimum at 10 and 50°C while the other at 11 and 70°C. The protease thermal stability was found to increase in the presence of CaCl2, indicating the proteases were metalloproteases.
Effect of extracellular polymers on freeze-thaw conditioning of activated sludge
Authors: Örmeci B. , Vesilind P.A.
Published: May 2018

In this study, the effects of extracellular polymers on freeze-thaw conditioning of activated sludge are investigated. Various physical and chemical extraction methods including centrifugation, blending, heat, EDTA, EGTA, and NaOH extraction were used to remove extracellular material from sludge matrix. The improvements in freeze-thaw conditioning were evaluated by commonly used measures of sludge dewaterability. The results of this study indicate that removal of extracellular polymers using relatively gentle extraction methods before freeze-thaw conditioning improves the sludge dewaterability after the freeze-thaw. In addition to extracellular polymers, cations also play an important role in determining the freeze-thaw effectiveness on activated sludge. Best dewaterability is achieved when both extracellular polymers and cations are removed from activated sludge before freeze-thaw conditioning.
Sulfate disinfection, stabilisation and heavy metal removal from sewage sludge – process description and preliminary results
Authors: Lowrie D. , Hobson J. , Stuckey D.C.
Published: May 2018

A new, closed loop process for the disinfection, stabilisation and removal of heavy metal from sewage sludge (consisting of a sludge/sulfuric acid reactor, hybrid H2S generator and H2S bioscrubber) is described. Preliminary results for total solids (TS), volatile suspended solids (VSS), chemical oxygen demand (COD), acetate and propionate destruction in the hybrid H2S generator have shown that digestion efficiency is not compromised in a hybrid reactor generating H2S compared to a methanogenic reactor. 70% of the electron flow in the hybrid H2S generator was diverted to methane at a COD:SO4 ratio of 5.45:1. Enough H2SO4 could be generated from the H2S emitted at this ratio to effect sufficient metal solubilisation and pathogen removal from primary sludge.
An inventory of riverine biodiversity in monsoonal Asia: present status and conservation challenges
Authors: Dudgeon D.
Published: May 2018

There are few parts of the planet where human impacts on riverine biodiversity are more apparent than in monsoonal Asia. Flow regulation, drainage-basin degradation and conversion of riverine wetlands to agriculture have been occurring for centuries, while pollution and over-harvesting have become important in recent decades. Concomitant species loss appears both ongoing and rampant. Uncertainty over rates of loss is imposed by the fact that the extremely rich biodiversity of Asian rivers has not been inventoried adequately. It is nevertheless evident that some taxa are gravely threatened. Specialist riverine birds have declined, turtles are highly endangered, and over-harvesting has severely impacted fishes - an effect that is exacerbated by pollution and flow regulation. A particular conflict that constrains biodiversity conservation is the tendency for dam construction, which damages river ecosystems, to produce tangible benefits for humans through hydropower generation and relief from floods and droughts. Resolution of such conflicts requires changes in perception: for instance, realistic economic valuations of the ecosystem goods and services provided by rivers, and promotion of flagship species as conservation icons to increase citizen awareness. Translation of awareness and knowledge to action, however, remains the essential prerequisite for societal commitment to the conservation of freshwater ecosystems.
Downstream flow event sampling of acid mine drainage from the historic Mt Morgan Mine
Authors: Taylor G. , Howes R. , Dulvenvoorden L. , Vicente-Beckett V.
Published: May 2018

Numerous scientific reports concur that the Dee River is heavily impacted by acid mine drainage from the historic gold and copper mine at Mt Morgan, Central Queensland. The water quality along the Dee River, for 18 km downstream of the mine site to its junction with Fletcher Creek, is characterised by low pH, typically 2.8 to 4.2. With respect to metal concentrations, the Dee River has been described as one of Australia's most polluted rivers. Measurements of pH along the Dee River clearly demonstrated the movement of a slug of acidic water down the river during each of the four flow events between November 2000 and February 2001. Laboratory analysis of water samples collected during November indicated Al, Cu and Zn concentrations orders of magnitude above ANZECC guidelines. Fish kills occurred with each flow event and killed an estimated total of 26,000 fish.
Opportunities for sustainable riverine management in the Queensland Murray-Darling Basin
Authors: Ellway C. , Murphy G. , Merton L. , Baumgartner D. , Hempseed A.
Published: May 2018

The RiverReach program has provided significant material, planning and educational resources to communities throughout the QMDB over the last three years. The devolved granting process has proven to be a valuable mechanism for the initiation of on-ground works and as a platform for the delivery of educational and awareness raising activities. The range of riverine management projects developed among riparian communities reflects both the socio-economic and the environmental circumstances. An increasing knowledge of riverine management issues among both the community and practitioners and a growing acceptance of the need for riverine management within the community has increased opportunities for sustainable riverine management in the region. While the range of riverine management issues is diverse, and their integration complex, the combination of all three aspects (financial assistance, technical advice, and awareness raising) has enabled significant management outcomes to be achieved.
Faecal contamination over flood events in a pastoral agricultural stream in New Zealand
Authors: Nagels J.W. , Davies-Colley R.J. , Donnison A.M. , Muirhead R.W.
Published: May 2018

Faecal bacterial dynamics during flood events were studied in the Topehaehae Stream near Morrinsville, New Zealand, in a catchment used for grazing dairy and beef cattle. During the rising limb of a natural flood event, E. coli bacterial concentration rose by more than 2 orders of magnitude and peaked at 41,000 cfu/100 mL. E. coli correlated closely with turbidity over the flood event, and both variables peaked close to the time of maximum flow acceleration rather than peak flow. An artificial flood on the same stream, created by releasing water from a supply reservoir during fine weather with no wash-in from the catchment, produced a broadly similar pattern of faecal contamination (peak E. coli = 12,500 cfu/100 mL). This and other evidence suggests that direct deposition of faecal matter by cattle in the stream channel may be of similar or greater importance than wash-in from land. The flood experiments have been useful for constructing a model of faecal bacterial yields, and they imply that exclusion of livestock from stream channels may appreciably improve water quality.
Optimization of nitrogen removal from piggery waste by nitrite nitrification
Authors: Eum Y. , Choi E.
Published: May 2018

The piggery waste characteristics greatly vary with types of manure collections and the amount of water used. If solids are separated well, the waste strength will be greatly reduced resulting in lower TCOD/TKN ratio of 4 (average). If solids are separated by a mechanical scraper, some solids will remain and the waste strength will be increased with a TCOD/TKN ratio of 7. This study was conducted to find an optimum operating condition for nitrogen removal with these two ratios. Nitrite nitrification was targeted because it could be a short cut process for savings in oxygen for nitrification and carbon requirements for denitrification. The study results indicated that nitrogen loading rate and pH were the most important factors to be considered for stable nitrite nitrification. The applicable nitrogen loads were estimated to be 0.3 to 2.0 kgTKN/oxic m3/d for high TCOD/TKN ratio without pH control. With higher pH > 8, NO2N/NOxN ratios in oxic stages even with lower nitrogen loads were increased. The SBR with low TCOD/TKN ratio less than 4 required additional alkalinity. For a complete denitrification, the influent TCOD/TKN ratio must exceed 6 with oxic/total reactor volume ratio of 0.5. Nitrite nitrification and denitrification could save about 35% in tank volume and 50% in carbon requirement, respectively. However, 9.5% oxygen saving could be expected during the operation with low TCOD/TKN ratio. The elevated temperature due to the heat released from COD removal also enhanced microbial activities for nitrification and denitrification as well as ammonia stripping. However, careful attention must be provided for the reactor temperature not to inhibit the nitrification process.
Isolation and characterization of the ethynylestradiol-biodegrading microorganism Fusarium proliferatum strain HNS-1
Authors: Shi J.H. , Suzuki Y. , Lee B.-D. , Nakai S. , Hosomi M.
Published: May 2018

We cultivated hundreds of sediment, soil, and manure samples taken from rivers and farms in a medium containing ethynylestradiol (EE2) as the sole source of carbon, so that microorganisms in the samples would acclimatize to the presence of EE2. Finally, we isolated an EE2-degrading microorganism, designated as strain HNS-1, from a cowshed sample. Based on its partial nucleotide sequence (563 bp) of the 28S rRNA gene, strain HNS-1 was identified as Fusarium proliferatum. Over 15 days, F. proliferatum strain HNS-1 removed 97% of EE2 at an initial concentration of 25 mg.L−1, with a first-order rate constant of 0.6 d−1. Unknown products of EE2 degradation, which may be more polar compounds that have a phenolic group, remained in the culture medium.
Ammonia recovery from high strength agro industry effluents
Authors: Altinbas M. , Ozturk I. , Aydin A.F.
Published: May 2018

The aim of the study was to investigate ammonia recovery from high strength agro industry effluents involving significant amounts of ammonia, by applying magnesium ammonium phosphate (MAP) precipitation technology. Two types of industrial effluents have been tested in the study. The first plant was an opium alkaloid processing industry and the second one was a baker`s yeast industry. High chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and unacceptable dark brown color characterized effluents from both industries. Effluents from the biologically treated opium alkaloid and baker's yeast industries were both applied at the stoichiometric ratio (Mg:NH4:PO4 =1:1:1) and above the stoichiometric ratio (Mg:NH4:PO4 =1.1:1:1.1) to MAP precipitation. NH4 removals of 61-80% were achieved at the pH of 9.2 at the stoichiometric ratio, whereas 83% NH4 removal was obtained at the pH of 9.2 above the stoichiometric ratio. Experimental studies performed on both anaerobically and/or aerobically treated baker`s yeast and opium alkaloid industry effluents have clearly indicated that MAP precipitation was an appropriate treatment option for NH4 removal or struvite recovery from high ammonia content agro industry effluents. Additional ammonia recovery studies were conducted on ozonated and Fenton's oxidation applied effluents and these have also indicated that the amounts of struvite and the quality of MAP precipitate was increased significantly. In this framework, MAP sludge recovered from combined biological and Fenton's oxidation treatment effluents were considered as a more valuable slow release fertilizer for agricultural use.
Ultimate azo dye degradation in anaerobic/aerobic sequential processes
Authors: Sponza D.T. , Işik M.
Published: May 2018

The treatability of Remazol Black-5 was studied in an anaerobic/aerobic sequential process. Laboratory scale UASB/CSTR reactors were used and operated at different organic loadings and HRTs to investigate the COD, color removal, and methane gas production efficiencies. The effect of both sludge age and HRT on the color and COD removal efficiencies were also investigated. The reactive dye used in this study contains the groups N = N, −SO3, S = O and is in use in some of the textile industries in Turkey. The studies were carried out in continuous mode and the effluent of the UASB reactor was used as feed in the CSTR reactor. COD removal efficiencies decreased from 56 to 27% with increases in COD loadings from 5 kg COD/m3.day and 25 kg COD/m3.day in the anaerobic UASB reactor. The color removals were 92 and 87%, respectively, for the aforementioned organic loadings. The methane percentages were found to be 50 and 76% at organic loading rates of 2.49 kg COD/m3.day and 14.8 kg COD/m3.day, respectively. 28, 42, and 90% COD removal efficiencies were obtained at sludge retention times of 1.7, 5.7 and 11 days in the aerobic CSTR reactor. Optimum sludge age was 11 days in aerobic reactor and 67 and 28% COD removal efficiencies were obtained at F/M ratios of 0.05–0.17 and 0.30–1.4 kg COD/kg MLSS.day. 90–95% color and 40–60% COD removal efficiencies were obtained depending on the applied organic loadings in the UASB reactor. The remaining COD was removed with a treatment efficiency of 85–90% in the aerobic CSTR reactor.
Biological and chemical treatment of solid waste from soy sauce manufacture
Authors: Nagai H. , Kobayashi M. , Tsuji Y. , Nakashimada Y. , Kakizono T. , Nishio N.
Published: May 2018

To reduce the solid waste in soy sauce refuse (SSR) that is a by-product of soy sauce fermentation, both biological and chemical treatment were examined. When anaerobic digestion of SSR was carried out at the amounts of 25 g/l under 30% (v/v) inocula of thermophilic methanogenic sludge at 50°C, 120 mM of CH4 was produced and 50% (w/v) of mixed-liquor suspended solids in SSR was decreased after 35 days. Although in this culture 30 days' cultivation was required to get 100 mM of CH4, when the same amounts of SSR (25 g/l) were repeatedly added to the culture, the time requirement to get 100 mM of CH4 could be reduced to 20 days and 15 days at second and third batch cultures, respectively. When SSR was treated with 5% (w/v) NaOH for 24 h, the supernatant contained 98% (w/v) of protein that were alkaline-solubilized and insoluble in the intact refuse, and the residual pellet contained insoluble fiber.
Treatment of winery wastewater in a sequencing batch biofilm reactor
Authors: Andreottola G. , Foladori P. , Ragazzi M. , Villa R.
Published: May 2018

Pilot-scale experiments were carried out applying the SBBR process (Sequencing Batch Biofilm Reactor) for the treatment of winery wastewater. The aim was the evaluation of the SBBR performance and the development of a control strategy based on dissolved oxygen (DO) for the optimisation of the SBBR treatment cycle and the minimisation of the energy supply. The results of the experimentation have confirmed the applicability of the SBBR process pointing out high COD removal efficiencies between 86% and 99%, with applied loads up to 29 gCOD m−2 d−1, corresponding to 8.8 kgCOD m−3 d−1. The on-line monitoring of DO concentration appeared as a good indicator of the progress in the COD biodegradation. The control strategy for the ending of the SBBR cycles was based on the time derivative of the DO concentration. The optimised control strategy makes it possible to obtain a steady quality of the effluent wastewater with an average daily applied load of 6.3 kgCOD m−3 d−1 rather than 3.5 kgCOD m−3 d−1 for the non-optimised SBBR cycle. The possibility of optimising the SBBR cycle through a simple control of the DO in the mixed liquor could be an interesting solution for the biological pre-treatment of winery wastewater to be discharged into sewerage or as a single-stage of a combined treatment plant for the discharge into surface water.