bluuebunny/crossref_metadata_2025 huggingface dataset:
Iron Forms That Influence the Growth and Musty Odor Production of Selected Cyanobacteria
Authors: Nakashima S. , Yagi M.
Published: May 2018

In order to clarify the mechanism of growth of musty-odor producing cyanobacteria, the effects of iron forms on growth and musty-odor production in four species of cyanobacteria, Oscillatoriabrevis, Anabaenamacrospora, Phormidiumtenue and Oscillatoriatenuis were studied using laboratory batch cultures. The former two cyanobacteria produce geosmin and the latter two produce 2-methylisoborneol (MIB). The growth of A. macrospora, P. tenue and O. tenuis was suppressed in the EDTA (chelating agent)-free CT medium. However, O. brevis grew well and produced geosmin in this medium as well as in the presence of EDTA. Thus, O. brevis showed an ability to utilize colloidal iron and even iron oxides for its growth. This suggests that O. brevis would be expected to produce a specific high affinity iron chelator (siderophore) in the chelator-free medium. In the presence of bathophenanthroline disulfonate (BPDS), a strong Fe(II) chelating agent, O. brevis and P. tenue were able to grow, but A. macrospora and O.tenuis did not. Furthermore, O.brevis was capable of growing in the medium containing a microbial siderophore, desferrioxamine B(DESF), instead of EDTA, but the other three cyanobacteria did not grow. These results show that O. brevis has an excellent ability to utilize a variety of iron forms including Fe (II I)-EDTA, Fe (II)-BPDS,.Fe (III)-DESF chelates, colloidal ferric hydroxide and more thermodynamically stable crystalline iron oxides (Fe2O3 and Fe3O4) in comparison with the other three musty-odor producing cyanobacteria isolated from Lake Biwa.
Removal of Musty-Odorous Compounds in Water and Retained in Algal Cells through Water Purification Processes
Authors: Ando A. , Miwa M. , Kajino M. , Tatsumi S.
Published: May 2018

Musty-odorous compounds, metabolites of some species of blue-green algae, are usually contained in both the water and algal cell bodies. The compounds in the latter solid phase were found to be easily removed by coagulation and sedimentation without breakpoint prechlorination (intermediate chlorination used instead). Chlorination of the algae results in an artificial release of the metabolite content into the surrounding water. When a large fraction of the compounds was present in the algal cell bodies, more than 60% of these compounds were removed in the intermediate-chlorination treatment. Powdered activated carbon treatment is effective in removing the compounds in the aqueous phase. However, the effectivness was usually limited in practical treatment to high concentrations of musty odor. On the other hand, the ozonation and granular activated carbon (GAC) treatment was found to be an effective method for removal. It was observed that the musty-odorous compounds were completely removed through the ozonation and GAC treatment system, which included coagulation and sedimentation without prechlorination.
The Use of Sodium Carbonate Peroxyhydrate to Treat Off-Flavor in Commercial Catfish Ponds
Authors: Martin J. F.
Published: May 2018

Sodium carbonate peroxyhydrate (SCP) was applied to seven commercial catfish ponds in Mississippi to study the effects of treatment on fish flavor and pond ecology. The seven ponds were treated on alternate days in the morning with two doses of SCP at 55 kg hectare−1 (average depth 1-1.6 m). In three of the ponds, a potent 2-methylisoborneol (MIB) producing planktonic Oscillatoria chalybea-like species that was initially present was absent from the water column after treatment. In addition, the fish from two of these ponds were judged on-flavor 7 to 10 days after treatment. The off-flavor chemicals in three other ponds were diminished when measured seven days after treatment and fish were harvested from two of these ponds 10-14 days after treatment. The fish from the other two ponds were harvested 21 days after treatment. In the sixth pond, the predominant algal species was a 2-methylisoborneol producing O. chalybea-like species at 380 cells ml−1 and the treatment was ineffective. The treatment was most successful when off-flavor was less than two months duration and where application of the chemical was accomplished uniformly over the entire pond surface.
Accidental Road Spilling of Polychlorobiphenyls – A Case History
Authors: Liberti L. , Petruzzelli D. , Tiravanti G.
Published: May 2018

Approx. 1,400 kg of Apirolio, an extremely toxic insulating oil mixture, containing polychlorobiphenyls (75.6%) and polychlorobenzenes (24.2%) with traces of dioxins and furans, were accidentally spilled by a truck transporting an electric transformer, along 12 kms of SS 16 bis speedway on Dec. 7th, 1988. After immediate off-limiting of the accident area, a reclamation strategy was adopted that, based on accurate analytical survey of the contaminated environments (asphalt, agricultural soil, trees, produce, groundwater), allowed safe decontamination of the area.
Incorporation of Oil Base Mud Cuttings from Drilling Wells within the Manufacture of Clay Bricks
Authors: Jordao E. P. , de Oliveira A. R.
Published: May 2018

The incorporation of oil base mud cutting from drilling operations within the manufacture of clay bricks, is considered as one alternative for reuse and final disposal of the OBMC. To evaluate such alternative, on site OBMC amended bricks were produced (15000 bricks at Plant “A”, in Rio Bonito, RJ, and 4000 bricks at Plant “B”, in Jundiai, SP). Plant “A” produces 100000 bricks per day, and Plant “B” 40000; in both plants the cuttings were added in controlled amounts to the normal clay used in the manufacture process.

The on-site experiments included the production of conventional bricks, 2.5% and 5% amended bricks. The laboratory tests included:–properties, leachate, and solubilization tests of the cuttings;–leachate and solubilization tests of the normal and OBMC bricks;–compression strength of the normal and OBMC bricks.

The paper describes the process employed in the brick manufacture and the laboratory experiments. It also presents the properties of the OBMC bricks, and the benefits to both the manufacturer and to environmental control programs.
Comparison of Biocenoses from Continuous and Sequencing Batch Reactors
Authors: Wanner J.
Published: May 2018

Sequencing batch reactors (SBR) are often used for research on nutrient removal systems. A model anaerobic-oxic SBR was compared with a compartmentalized continuous-flow system. The levels of COD, phosphorus, and nitrogen removal in both systems were comparable but the biocenoses differed significantly. The SVI values of activated sludge from the continuous reactor ranged between 100 and 200 ml/g although no significant occurrence of filamentous microorganisms was observed. The sequencing batch reactor produced activated sludge with the SVIs below 100 ml/g and with high settling velocities. Filamentous microorganisms were frequently observed in the biocenosis of the SBR. The differences in settling properties and filamentous growth in both reactors are discussed and explained.
The Stability of Anaerobic Digesters Operating on a Food-Processing Wastewater
Authors: Hawkes F. R. , Rozzi A. , Black K. , Guwy A. , Hawkes D. L.
Published: May 2018

The response to step overloads of laboratory-scale contact process and UASB reactors and a pilot-scale anaerobic filter is examined. The reactors were operated on ice-cream waste water and changes in operational parameters including VFA levels and COD reduction were monitored. In the laboratory-scale experiments, feed strength was increased from 4500 to 22,000 mg [O] per litre for periods of 2 to 12 hours in contact process and one and two-stage UASB reactors. UASB stability was improved by supplementing with trace metals. Two-stage UASB's gave better COD removals under shock loading than single-stage UASB's or contact process reactors. In an 8 hour step overload experiment on the pilot-scale reactor, bicarbonate alkalinity was shown to be a good indicator of instability.
Performance of the 5 MLD UASB Reactor for Sewage Treatment at Kanpur, India
Authors: Draaijer H. , Maas J. A. W. , Schaapman J. E. , Khan A.
Published: May 2018

The present paper describes the performance of a 1200 m3 UASB reactor treating 5000 m3 municipal waste water per day at Kanpur, India. The reactor was constructed in three parallel compartments of 600, 300 and 300 m3 respectively to study the influence of various design and operational parameters on process performance. The 600 m3 compartment is the reference unit. In one of the 300 m3 compartments the effluent overflow gutters are provided with baffles to prevent overflow of floating material. The other 300 m3 compartment is provided with a double amount of inlet pipes at the bottom of the reactor to assess the effect of a more dense distribution of the influent.

The start-up of the reactor was carried out without addition of seed sludge since the influent contained the necessary seeding material.

Data collected over a period of twelve months showed that there was an average reduction in COD, BOD, and TSS concentrations of respectively 74, 75, and 75 % at a hydraulic retention time of 6 hours. Excess sludge production was 0.2 kg TSS/m3 waste water, having 60-70 percent ash. It could be dried in six days on open sludge drying beds. The biogas yield was 0.05 to 0.10 m3/kg COD removed. The gas had 75 to 80 percent methane. Also during winter time the treatment efficiency and process stability remained good. The compartment provided with baffles showed better removal efficiencies for COD, BOD, and TSS than the other compartments. A double number of inlet points did not show an increase in removal efficiency. A density of one inlet point per 3.7 m2 is sufficient to provide a properly distributed influent in the reactor.
Full-Scale Application of the UASB Technology for Sewage Treatment
Authors: Schellinkhout A. , Collazos C. J.
Published: May 2018

In recent years, many pilot-scale investigations were reported on the application of the UASB concept for sewage treatment. Information about large-scale experience is scarce, however. This paper describes the experience obtained with the design, construction and initial operation of a 160,000 PE (31,000 m3/day, 8 MGD) plant in Colombia, consisting of UASB reactors and a facultative pond in series. It describes the possibilities and limitations of the use of prefab concrete as a building material for UASB reactors. The real cost of erection of the plant was USD 17 per capita; the cost for operation and maintenance amounted to USD 1.50 per capita.
Treatment of Wastewater with a Low Concentration of Organics Using an Anaerobic Fluidized Bed Reactor
Authors: Maragno A. L. F. C. , Campos J. R.
Published: May 2018

In this work performed in the Laboratory of Sanitation of São Carlos Engineering School- University of São Paulo, the results obtained from the operation of a laboratory scale anaerobic fluidized bed reactor are presented for the treatment of a synthetic wastewater with a mean COD of 557 and 700 mg/l during the two phases in which the reactor was studied. In the first phase (Phase A) the mean hydraulic residence time () was maintained at 1.0 h and in the second phase (Phase B), 1.5 h. The duration of each phase, counted from the initial startup period, was 197 days and 108 days, respectively. The reactor was constructed using an acrylic tube of 1.50 m height and a total volume of 10.5 1. The support material consisted of sand with the grains retained between sieves with openings of 0.210 mm and 0.149 mm. The total height of the fluidized bed was maintained at 1.40 m throughout the experiment. The reactor was operated at ambient temperature (13°C to 31°C), and was fed with synthetic wastewater composed mainly of bovine liver extract, glucose, sodium bicarbonate and ammonium acetate. The results of physical and chemical analyses: pH, alkalinity, temperature, volatile acids, COD, nitrogen and phosphorus are presented. An evaluation was also made during the experiment of the thickness of the biofilm gathered on the sand grains collected over the whole height of the reactor. The mean efficiency of COD removal attained was 62% for the first phase and 71% for the second phase.
Anaerobic Treatment of a Petrochemical Wastewater from a Terephthalic Acid Plant
Authors: Macarie H. , Noyola A. , Guyot J. P.
Published: May 2018

Anaerobic treatment of terephthalic acid plant wastewater was tested using two UASB reactors (T and U) and a downflow tubular fixed film reactor. UASB T was inoculated with sludge sampled from an anaerobic stabilization pond receiving waste activated sludge from a petrochemical industry treatment plant. UASB U and the fixed film reactor were inoculated with anaerobically adapted activated sludge from a municipal plant. Raw effluent had to be settled and neutralized before reactor feeding. Sedimentation resulted in 70% TSS and 37% COD removal. UASB digesters presented comparable treatment efficiencies with rather low COD removals: the best results were 46.4% for UASB T at 2.6 kg COD/m3.d and a hydraulic retention time (θ) of 2.7 days and 43.9% for UASB U at 2.2 kg COD/m3.d and θ of 3.2 days. The performance of the tubular reactor was much higher, 74.5% COD removal at 1.89 kg/m3.d and θ of 3.4 days. The better efficiencies of this last digester are explained mainly by a higher VSS content and a better resistance to toxicity caused by the aromatics present in the wastewater. A primary settling-anaerobic-aerobic process is proposed as an alternative to the conventional aerobic process for treating terephthalic wastewater, but disposal of solids from primary sedimentation and cost of neutralization have to be considered before application.
Acclimatization of a Methanogenic Consortium to Polychlorinated Compounds in a Fixed Film Stationary Bed Reactor
Authors: Modesto Filho P. , Amerlynck P. , Nyns E.-J. , Naveau H. P.
Published: May 2018

With the objective of destruction of organic toxic or recalcitrant compounds by a microbial anaerobic mixed population, a new concept has been devised : the Destox concept. It has been applied here to the destruction of a toxic mixture of about 30 polychlorinated aliphatic compounds (PAC-MIX 1), including 51 % of hexachloro-l,3-butadiene. The basic step for initiating the degradation is thought to be reductive dechlorination by microbial interspecies hydrogen transfer in a system using at all times a non-toxic co-substrate as major source of carbon and energy. In an upflow laboratory-scale reactor with a fixed-film stationary-bed, fed with a co-substrate, amounts of 48 mg/litre working volume per day of PAC-MIX 1 have been added during intermittent periods of time. This paper presents, over a period of 421 days, the evolution from a situation of complete inhibition of all microbial activity, from fermentative to methanogenic, into a situation of partial acclimatization, the fermentative and hydrogenotrophic methanogenic bacteria having become resistant to the action of the toxic mixture while acetogenic bacteria seem in the process of acclimatization. The methane production rate was maintained at 30% of the reference value, together with continuous accumulation of mainly acetate and to a lesser extent propionate.
Anaerobic Digestion of Distillery Wastewater in a Two-Phase UASB System
Authors: Shin H.-S. , Bae B.-U. , Lee J.-J. , Paik B.-C.
Published: May 2018

A two-phase UASB system was operated for high-rate treatment of concentrated distillery wastewater. The phase separation was obtained by adjusting pH in each reactor. When influent SS concentration was 4.1 g/l, the first phase UASB reactor was effectively operated up to the loading rate of 16.5 kg COD/m3.day, producing 3.9 g HAc/l.day. In the methanogenic UASB reactor, loading rates up to 44 kg COD/m3.day could be applied while removing 80 % of influent COD with a specific gas production of 16.5 l/l.day. After the formation of granular sludge in both reactors, it was possible to maintain the appropriate pH in the first phase only by recirculating the effluent from the methanogenic phase without the addition of alkaline chemicals. The morphological study on the granular sludge consortia was made with both scanning and transmission electron microscopes. It was interesting to find the granules of different color and shape in the acidogenic phase in 90 days and in the methanogenic phase in 120 days after start-up. The acidogenic granular sludge mainly consisted of long chains of large rods, short plump rods, and various size of cocci, which have a different shape and cytoplasmic appearance from common methanogenic bacteria. Whereas the long multicellular filaments of Methanothrix spp. were prevalent in the methanogenic granule, diverse bacteria were entrapped therein.
Sediment Origins, Deposition and Build-Up in Combined Sewer Systems
Authors: Ashley R. M. , Crabtree R. W.
Published: May 2018

The origins of sediments and associated pollutants found in sewers are clear, and demonstrable temporal and spatial variations have been found. It is likely that these variations are such that it is not possible to formulate general rules for the rates and nature of surface wash-in to sewers. Sanitary sources, however, are more amenable to deterministic assessment. The rates of build-up of sediments in sewers vary widely, and whilst it is possible to estimate the build-up in small-sized collector sewers, no general rules are yet available to predict the rate of deposition in larger sewers. There are broad similarities in the nature of sediments found in sewers in terms of particle size and pollutant characteristics. It is possible to formulate a pragmatic taxonomy for distinct classes of these sediments in order to facilitate understanding of sediment effects and to assist engineers with developing control strategies.
Input and Characterization of Sediments in Urban Sewer Systems
Authors: Xanthopoulos C. , Augustin A.
Published: May 2018

This paper discusses informative data on the particle size distribution in sewer sediments including data on the contamination of the individual fractions with micropollutants. For this purpose, two low-gradient sewer systems, a combined and a separate system, were sampled. This paper will show the differences between the two systems' sediments characteristics. Furthermore the sewer sediments will be compared to settleable solids introduced by street runoff into the sewer system and deposits found in a detention basin of the combined sewage. Finally, we will propose a simplified analysis method based on the observed data to describe the cohesivity of the sewer sediments.
Field Investigations on Sediment Occurrence and Behaviour in Brussels Combined Sewers
Authors: Verbanck M.
Published: May 2018

Although sewer sediments are now widely recognized as a major source of misfunction of urban drainage systems (for both hydraulic and environmental considerations), it is still too infrequent that priority of research activities in this area is given to field studies. The measuring campaigns conducted since 1986 in the drainage system of Brussels-North have been focused on sedimentation processes in the major sewer lines. There is an obvious distinction to be made between solids constituting the sediment bed of a man-entry sewer, which are relevant for its hydraulic capacity, and the ones contributing to the pollutional impact of CSOs upon receiving waters.

The material which is removed several times a year from the main trunk sewer of Brussels is coarse, granular and has a low environmental impact, notably because of its limited mobility. This appears to be due to a very efficient granulometric grading, as a result firstly of the retention of the coarsest solids in highly selective gully-pot inlets, and secondly of an elutriation process removing from the sediment bed all fine organic-rich particles during daily peak flows.

There is evidence to show that the build-up of the sediment bed in these large-sized sewers is driven by a bed-load process (active even during dry spells), while the solid material responsible for the detrimental effects of CSOs (which is much finer) is primarily transported through wash-load and suspended-load.
Presence of Indicators and Salmonella in Natural Waters Affected by Outfall Wastewater Discharges
Authors: Moriñigo M. A. , Muñoz M. A. , Cornax R. , Martinez-Manzanares E. , Borrego J. J.
Published: May 2018

The presence of the pathogenic microorganism Salmonella as well as indicator microorganisms (total and faecal coliforms, faecal streptococci, Clostridium perfringens, and coliphages) was investigated in three different aquatic environments affected by sewage discharges. The relationships between indicators and Salmonella depended mainly on the source of faecal discharges and on the survival capability of the microorganisms in aquatic environments. The microorganisms most closely related to Salmonella spp were faecal coliforms and C. perfringens, the latter yielding also the highest linear regression slope value. Detection percentages of Salmonella spp were high even at a low level of pollution, which allowed detection of the pathogens in the absence of classical indicator microorganisms in the sample.

The results obtained in the present study showed that there were no differences in survival rates between the serotypes of Salmonella tested. Moreover, Salmonella spp exhibited a similar persistence to E. coli in aquatic ecosystems, particularly in marine environment.
Plume Dispersion of Dilute Suspensions: A Model of Barge Overflow Adapted for Use in a Personal Computer
Authors: Vieira M. E. C. , Subramanian A. , Bokuniewicz H. J.
Published: May 2018

A practical method was developed to estimate the areal extent of the plume associated with the overflow of dredged material during barge filling operations in shallow waters. The predictive model is based on the Okubo-Pritchard relationship for horizontal diffusion; it solves the transport equation which governs the distribution of total suspended solids or dissolved species. The model runs in a Personal Computer and provides the spatial distribution of particulate concentrations in the plume from minimum information on local hydrography, the intensity of advective and dispersive processes and the characteristics and discharge rate of the dredged material. The extent of the plume is defined as the isoline of acceptable concentration of a specified material. The rate of decay of the plume once the overflow terminates is also computed.
Debate on Uncertainty in Estimating Bathing Water Quality
Authors: Larsen T.
Published: May 2018

Estimating the bathing water quality along the shore near a planned sewage discharge requires data on the source strength of bacteria, the die-off of bacteria and the actual dilution of the sewage. Together these 3 factors give the actual concentration of bacteria on the interesting spots on the shore. Each of the 3 factors varies with time and can only be estimated roughly with significant uncertainty. The author wants to debate the necessity of accepting these uncertainties and accordingly taking the uncertainty into the modelling of the consequence of a particular discharge.
Marine Disposal of Waste Water from Combined Sewerage Systems - Problems, Politics, Practicalities
Authors: Head P. C. , Crawshaw D. H.
Published: May 2018

Since 1986 North West Water (NWW) has been involved in planning and designing major coastal sewerage and sewage treatment schemes to improve the quality of some 65 km of its extensive coastline. These schemes, notably those for the Fylde Coast, the Ribble Estuary and the Cumbria Coast, involve improvements for a population of around 555 000. Determining the appropriate treatment scheme for each of these areas during a period of changing national and international attitudes towards discharges to the environment in general, has caused a number of problems. In particular, the general movement towards a more precautionary approach to discharges to all sectors of the environment, resulted in extensive local debate about the adequacy of some of the early proposals, put forward to meet much more limited objectives. It is no longer acceptable for decisions to be based almost entirely on the technical merits of proposals but necessary to ensure that the requirements of local and national political opinion are taken fully into consideration. This can only be done by setting up suitable consultation mechanisms, with local interests and regulatory authorities, to ensure that the full environmental and economic implications of various alternative solutions are explored before any decision to adopt any particular scheme.
Anaerobic Biofiltration versus Aerobic Membrane Filtration: Comparison on a Difficult Substrate
Authors: Sauvegrain P. , Tazi-Pain A. , Rogalla F. , Valter F.
Published: May 2018

Several methods were compared to treat heat treatment liquor on a municipal wastewater treatment plant, to reduce loading and allow upgrading.

To ensure low suspended solids in the return flows, granular anaerobic filters were chosen in parallel with membrane treatment:–an upflow wood-based charcoal anaerobic filter–an upflow floating polystyrene anaerobic filter–an aerobic reactor (activated sludge) coupled with microfiltration.

Very similar loading rates and removal efficiency was obtained with the anaerobic filters; they allow to treat highly concentrated effluents in a detention time of 10 h but COD removal efficiency was limited to 60%.

The higher contact time of up to 7 days in aerobic treatment, coupled with microfiltration, achieves elimination of 85% of COD and 95% of BOD. Nevertheless, loading rates and biomass concentrations remained low and flux on the membranes was heavily restricted.
Biological Denitrification System with Membrane Separation for Collective Human Excreta Treatment Plant
Authors: Magara Y. , Nishimura K. , Itoh M. , Tanaka M.
Published: May 2018

In Japan there are about 1200 collective night-soil treatment plants which treat about 42,700,000 population equivalent of night soil and 30,000,000 population equivalent of on-site treatment tank sludge. A sophisticated night-soil treatment system has been developed which uses ultramembrane filtration for the solid-liquid separation stage in a biological denitrification process devised by a joint research and development project between the governmental research institute and a number of private industries.

The effluent from the new system can be anticipated to have levels of BOD, SS, COD, T-N and T-P of about 5 mg/l, 0 mg/l, 35 mg/l, 20 mg/l and less than 0.3 mg/l, respectively. The investment and operational cost of the new system is less than or equivalent to a conventional biological denitrification plant. Furthermore the new system has the advantage of requiring less land and fewer operators. Because of these advantages the new system, i.e. a high-rate biological denitrification process with ultramembrane filtration, is going to be the major system for collective night-soil treatment plants in Japan.
Application of Electrochemical Membrane Processes to the Treatment of Aqueous Effluent Streams
Authors: Voortman W. J. , Simpson A. E. , Kerr C. A. , Buckley C. A.
Published: May 2018

Electrolysis cellss incorporating ion-exchange membranes are used in the chlor-alkali industry. Similar cells may also be used for selective concentration, purification or chemical conversion of aqueous effluents. The Pollution Research Group, University of Natal has applied electrochemical membrane processes to the recovery of sodium hydroxide from textile scour and bottle wash effluents, the removal and neutralisation of sulphuric acid from underground mine water and the removal of ammonium nitrate from effluents arising in a nitrogen chemicals manufacturing complex.
Ground Water Pollution by Volatile Organochlorines in Japan and Related Phenomena in the Subsurface Environment
Authors: Hirata T. , Nakasugi O. , Yoshioka M. , Sumi K.
Published: May 2018

The groundwater pollution by volatile organochlorines has been increasingly becoming a major environmental issue in many developed nations. In particular, trichloroethylene and tetrachloroethylene were widely detected in regional groundwaters of Japan. The paper describes the characteristics of groundwater pollution of Japan on the basis of the nationwide survey results, and introduces an incident in industrial site and subsequent counter-measures. In this site detailed investigations of 26 monitoring wells surrounding the pollutant source have continued to date since remedial operation in 1984, and cis-l,2-dichloroethylene was discovered to be created as intermediate product from trichloroethylene during the biodegradation process. Furthermore, the long-term continuous surveys reveal two types of organochlorine behavior in ground-water, that is, (l)cis-l,2-dichloroethylene concentration is proportional to that of trichloroethylene and (2)cis-l,2-dichloroethylene concentration is nearly constant in no relation with trichloroethylene behavior, in seasonal variation of individual well-water.
Distribution of DDTs in the Sediment of Lake Biwa
Authors: Kawabe K. , Maegawa A. , Yamanaka S. , Nomura K.
Published: May 2018

An investigation was carried out to determine the residual tendency of DDT and its derivatives in the sediment of Lake Biwa, Japan, where the banning of DDT took effect some 15 years ago. Of the two basins shaping Lake Biwa, the frequency of detection of DDT was higher in the Northern Basin than in the Southern Basin. In the Southern Basin, the area of DDT detection was more confined than that of DDE detection. Therefore, it is reasonable to assume that DDT has been decomposing more rapidly in the Southern Basin than in the Northern Basin. Based on the profile obtained for the vertical distribution of DDTs, it can be inferred also that the amount of DDT and DDE flowing in from land has been decreasing in the past years. DDT has hardly been decomposing into DDE at the deeper part of the Lake.
Alternative Options for Atrazine: Incidence on Water Treatment Device
Authors: Montiel A. , Weité B.
Published: May 2018

In recent years, triazine residues are often evidenced in surface waters as well as in underground waters. The European standards for the maximal level of each pesticide in water for human consumption is 0.1 µg.l−1 which raises problems for triazines such as atrazine or simazine.

New molecules have been designed to replace atrazine and the aim of our study is to evaluate on a pilot plant the outcome of two triazines wich could be used instead of atrazine and simazine; these two triazines are cyanazine and terbuthylazine. These triazines are not removed by coagulation, floculation, decantation. Cyanazine is well eliminated by slow sand filtration. Ozonation has no effect on cyanazine but eliminates 40 % of terbuthylazine. Mechanism of elimination of terbuthylazine on slow sand filters seems to be reversible adsorption which can lead to re-release of this pesticide in case of variation of concentration in the influent water.
Influence of the Drainage Basin input on a Pathogenic Bacteria (Salmonella) Contamination of a Mediterranean Lagoon (The Thau Lagoon - France) and the Survival of This Bacteria in Brackish Water
Authors: Galès P. , Baleux B.
Published: May 2018

Research has been carried out over a 10 month period with the aim of identifying potential sources of Salmonella contamination in a Mediterranean lagoon (the Thau Lagoon). Two types of source have been sampled, permanent ones which are checked monthly, and incidental ones.

The highest occurrence of Salmonella is linked to episodic events brought on by rainfall. After summer low water levels, the rising of river water brings back into circulation water from pools previously formed by waste water from sewage treatment plants and sediments, thus creating a significant source of bacteria. The sewer system can also supply the Thau Lagoon with varying quantities of Salmonella when the system breaks down, and also when it is overloaded by an excess of rainwater following a storm. Monthly checks reveal that discharges of Salmonella occurred occasionally in permanent inputs, whereas the outflow from the Mèze pond provides a quasi-permanent, but negligible, source of contamination. The major risk of shellfish breeding contamination is thus associated with rainfall, and the occasional overflow of raw wastewater.The survival of Salmonella in the lagoon waters varies in function with the seasons, and the risk is greatest at those times of the year when autopurification can be affected.
Validation of Computer Models for High Rate Algal Pond Operation for Wastewater Treatment Using Data from Mediterranean and Scottish Pilot Scale Systems: Implications for Management in Coastal Regions
Authors: Fallowfield H. J. , Mesple F. , Martin N. J. , Casellas C. , Bontoux J.
Published: May 2018

The High Rate Algal Pond (HRAP) is an efficient treatment system for controlling wastewater pollution by reducing the organic matter and the inorganic nutrient content. Deterministic modelling of algal growth could provide a rational basis for pond design and management. This study compares two deterministic models for algal growth in HRAP s. The Montpellier model predicts the chlorophyll a concentration in the HRAP s, based on daily observed irradiance, calculated temperature, observed chlorophyll a content, zooplankton and grazable phytoplankton numbers. The Auchincruive model predicts algal dry matter and oxygen production at 1 cm intervals throughout the pond depth, based on daily irradiance, day length, temperature minima and maxima and the chlorophyll a or dry matter content. Both models correlate well with weekly measurements of chlorophyll a contents in HRAP s treating rural sewage at Mèze, France. The Montpellier model also correlated well with daily measurements of chlorophyll a contents in an HRAP treating an artificial sewage at Auchincruive, Scotland. The correlation was less good for the Auchincruive model. Reason for these discrepancies and the relative advantage and disadvantage of each model are discussed.
Estuarine Management from a Global Economic Perspective
Authors: Bundy M. M.
Published: May 2018

It has been man's excessive use of natural resources for industrial raw materials, his misuse of the environment as a place to discard waste and unwanted materials, and the high rates of consumption of commercially valued resources that is causing serious local and global consequences. Many of our environmental problems are the result of exceeding the constraints imposed by this inherent finiteness of the environment. Now and in the future, local and global decisions will have to be made which recognize that environmental resources are finite and that the assimilative capacity of the ecosystem is limited. In addition to providing estuarine managers with a conceptual understanding of environmental problems, economics has provided decision makers with practical analyses of potential solutions. This paper provides an overview of these issues. The basis of the historic relationship between environmental impacts and man's activities is presented followed by a discussion of how future problems can be prevented. Some examples of the contribution of economic research is also presented.
Status and Future Perspective of Hazardous Waste Management in Korea
Authors: Cho K.-M. , Yoon S.-S. , Koo J.-K. , Yoo H.-C.
Published: May 2018

In this paper, classification and generation of hazardous wastes, related laws, and the hazardous waste management system currently employed in Korea are introduced. Recently, rapid and sustaining increase of generation rate, unsatisfactory reuse and recycle, inaccurate analysis and testing, and illegal treatment and disposal have been pointed out as major problems of hazardous waste management in Korea. In order to resolve these problems, the future directions and priorities in hazardous waste management in Korea are suggested.
Biodegradation of Ethylene Glycol in Simulated Subsurface Environments
Authors: McGahey C. , Bouwer E. J.
Published: May 2018

Ethylene glycol is regularly used as an industrial solvent and in vehicular anti-freeze and de-icing compounds. Significant quantities of it are released into treatment streams and onto land. The aim of this study was to establish rates of biodegradation of ethylene glycol in simulated subsurface environments. The utilization of ethylene glycol as substrate by microorganisms naturally occurring in soil and groundwater was monitored over time while substrate concentration, soil type, temperature and nutrient level were varied. Batch studies at 100 and 1000-ppm ethylene glycol demonstrated that increasing substrate concentration decreased the rate of its biotransformation as the first-order kinetic rate constant decreased from 1.01 to 0.95 days−1. Further increase in initial concentration to 10,000-ppm resulted in minimal substrate disappearance from solution which was likely due to oxygen limitation. Studies with two different soils under identical environmental conditions and substrate concentrations indicated soil type had a clear effect on biodegradation rate. Lowering the temperature from 25° to 10°C for a given soil retarded the degradation rate by a factor of 2.44, but at each temperature greater than 99% removal was achieved in less than 7 days. Removal of nutritional amendments from the microbial population had only a slight impact on biotransformation rate. Unamended microcosms still exhibited nearly complete ethylene glycol transformation in 3 days as compared to 2 days for amended microcosms. Groundwater served as a satisfactory bacterial inoculum and generated a rate constant only slightly lower (0.76 days−1) than that found for the soils. All results were comparable to those found by others for the biotransformation of linear alkylbenzene sulfonates (LAS) or of ethylene glycol by activated sludge.
Interactions Between Nonionic Surfactant Monomers, Hydrophobic Organic Compounds and Soil
Authors: Edwards D. A. , Liu Z. , Luthy R. G.
Published: May 2018

Nonionic surfactant at aqueous-phase concentrations less than the CMC can affect the distribution of hydrophobic organic compounds (HOCs) in soil/aqueous systems. Sub-CMC levels of nonionic surfactant can enhance the apparent aqueous-phase HOC solubility, increase the soil organic carbon content due to surfactant sorption, and modify the value of the HOC soil/aqueous distribution coefficient. Experimental data quantifying these effects are presented for several HOCs and nonionic surfactants. A method is proposed for predicting the distribution of HOC between soil and bulk solution with sub-CMC aqueous-phase concentrations of nonionic surfactant.
Chelating Resin versus Ion-Exchange Resin for Heavy Metal Removal in Toxicity Fractionation
Authors: Mazidji C. N. , Koopman B. , Bitton G.
Published: May 2018

A chelating resin (Chelex 50-100) and ion-exchange resin (Dowex 50W-X8) were evaluated for removal of heavy metals in toxicity fractionation. Microtox and β-galactosidase activity were employed as toxicity endpoints. The resins were packed into 4 raL glass Pasteur pipettes for use. Chelating resin provided complete removal of toxicity due to polyvalent heavy metal cations (Cd, Cu, Hg, Pb, Zn). Ion-exchange resin was ineffective in removing mercury toxicity. Neither resin provided complete removal of Ag+ toxicity. Toxicity of organic compounds was, at most, partially removed. Performance of the ion-exchange and chelating resins was insensitive to hardness and pH. Based on these results, chelating resin is recommended for heavy metal removal as part of a toxicity fractionation procedure.
Removal of Chromium (VI) and Other Heavy Metals from Groundwaters in Neutral and Alkaline Media
Authors: Zotter K. , Licskó I.
Published: May 2018

A method has been developed for removing the dissolved chromium(VI) and nickel compounds from groundwaters polluted as a consequence of uncontrolled solid wastes disposal. The chromium(VI) compounds (4-25 mg/L)were reduced in both neutral and alkaline media (10.0-11.0 pH range) with the help of FeSO4.7H2O. The partly colloidal, poorly water-soluble chromium(III) hydroxides developed in the course of the oxidation-reduction processes and the nickel compounds precipitated in an alkaline medium are coagulated by the iron(III) hydroxides produced. The addition of an anionic flocculant promoted the flocculation processes, so that in the effluent from conventional solid-liquid phase separation (settling and sand filtration) the chromium (and nickel) concentration was lowered to below the 100 µg/L level. The effluent can thus be recharged safely into the soil, or discharged into a recipient.
Stimulation of Biological Uptake of Heavy Metals
Authors: Ghosh S. , Bupp S.
Published: May 2018

This research was conducted to investigate the relative capabilities of unacclimated, acclimated, and cysteine-cystine-stimulated aerobic cultures to remove heavy metals. Loss of organism viability was observed at metal concentrations above 30 mg/L, however, loss of cell viability did not affect metal uptake. Metal-complexing capacities from 0.041 to 2.13 mg/mg protein were observed. Metal removal from binary and ternary mixtures exceeded those of single metals. Surprisingly, culture acclimation resulted in reduced metal uptake. However, a cysteine-cystine-stimulated culture had substantially increased metal-removal capabilities possibly due to the synthesis of metallothionein-like proteins. Biopolymers of the unacclimated organisms had an affinity for metal binding of the order: Cu > Pb > Cd. This research points to the feasibility of in-vitro detoxification of high metal-content hazardous wastes by cell materials derived from cysteine-cystine-stimulated chemostat cultures. Coupling in-vitro metal complexation with metal leaching from biosolids could provide an opportunity for recycling hazardous heavy metals.
Sensitized Photo-Degradation of Chlorophenols in a Continuous Flow Reactor System
Authors: Li X. , Fitzgerald P. , Bowen L.
Published: May 2018

A dye-sensitized photo-oxidation process has been developed in a continuous flow reactor system. Chlorophenols from mono- to penta- in synthetic solutions were successfully degraded in the presence of visible light radiation, methylene blue and air aeration. Investigation on some relations between reduction ratio of chlorophenol and dose number, air flow rate, and volumetric rate of light absorption shows that dose number as the combination of light intensity and retention time is a critical factor for optimum design. The amount of the air demand per unit of reduced chlorophenol is estimated as about 50 - 80 L.g−1. The residue of methylene blue in wastewater can be removed by passing through an adsorption column filled by natural zeolite (clinoptilolite). Some real wastewaters from coke plant, paper mill and machinery factory were treated in the system. After 1 hour treatment, chlorophenol can be degraded from 90 to 99% and COD was reduced from 30 to 60% depending on the composition and characteristics of the wastewaters.
AOX Removal from Bleached Kraft Mill Wastewater: A Comparison of Three Biological Treatment Processes
Authors: Hall E. R. , Randle W. G.
Published: May 2018

Laboratory scale activated sludge (AS), facultative stabilization basin (FSB) and aerated stabilization basin (ASB) processes were operated under controlled parallel conditions to assess the AOX (adsorbable organic halogen) removal efficiencies attainable in each. A comparison of the results obtained under a variety of operating conditions indicated that higher removal efficiencies of total and filterable AOX were achieved in the FSB and ASB processes than in the AS system. Data are also presented to indicate the extent to which influent AOX was removed by biodegradation, biosorption and off-gas stripping.
The Removal of Chlorinated Organics from Conventional Pulp and Paper Wastewater Treatment Systems
Authors: Bryant C. W. , Avenell J. J. , Barkley W. A. , Thut R. N.
Published: May 2018

A two-year survey of adsorbable organic halide (AOX) removals was conducted for eight full-scale wastewater treatment systems operated at pulp mills in North America. The resulting AOX database, one of the most comprehensive currently available, supports several significant findings.

AOX removals averaged 46% for the two activated sludge systems and 34% for the five aerated stabilization basins (ASBs). Both the activated sludge facilities and ASBs averaged removing over half of the influent low molecular weight AOX. The average removal of high molecular weight AOX varied among mill sites from 1% to 47% and was not correlated with the type of treatment process used. The best-performing treatment facility, located at a sulfite mill receiving nearly 100% hardwood furnish and using an activated sludge treatment system, was able to consistently remove 53% of the AOX, 62% of the low molecular weight AOX, and 47% of the high molecular weight AOX in bleaching wastewaters. Factors responsible for this high performance are not currently understood. Effluent AOX was strongly correlated (R2 = 0.90) to the influent loading for ASBs. In-mill improvements such as the use of oxygen and peroxide as well as chlorine dioxide substitution reduce influent AOX loading, apparently with minimal impact on treatment plant removal efficiency.
Biological and Advanced Treatment of Sulfate Pulp Bleaching Effluents
Authors: Çeçen F. , Urban W. , Haberl R.
Published: May 2018

Spent bleaching effluents (from chlorination (C) and extraction (E) stages) of a sulfate pulp mill were subjected to bench-scale biological and advanced treatment.

Although > 90 % of the influent BOD5 could be removed in an activated sludge process, the effluent still contained high amounts of resistant substances. The maximum COD removal was about 50 %; the removal rates achieved in the parameters TOC, DOC, AOX, SAK (254 nm) were even lower. The biological treatment led to an increase in color (436 nm) up to 40 %.

The biologically pretreated effluent was further treated by ozone or ozone/irradiation. The DOC, COD, color (436 nm), SAK (254 nm) and AOX removal rates amounted to 61 %, 81 %, 98 %, 92 % and 92 %, respectively. These methods led simultaneously to an increase in biological biodegradability as reflected by an increase in BOD5. A comparison of the results obtained for raw and biologically pretreated wastewaters showed that biodegradable substances should first be removed from the wastewater since otherwise the effectiveness of these methods decreased.

The coagulation/flocculation of biologically pretreated effluent showed that FeCl3 was the most effective coagulant and that removal rates > 90 % could be achieved. The treatment with various powder activated carbons showed that a dosage of 10 g/l was required to achieve elimination rates > 90 % in the parameters DOC, COD, color (436 nm) and SAK (254 nm). Adsorption isotherms were developed for every activated carbon and adsorption constants were calculated.
Improved Biological Nitrification Using Recirculation in Rotating Biological Contactors
Authors: Klees R. , Silverstein J.
Published: May 2018

The effect of recirculation on biological nitrification in rotating biological contactors (RBCs) was examined in an on-site pilot-scale RBC system which simulated full-scale plant RBC operations at the Longmont, Colorado, Wastewater Treatment Plant (LWWTP). Two LWWTP wastewater streams were used as pilot RBC influent. One wastewater stream, designated the “fresh” influent, was first stage trickling filter effluent. The second stream, designated the “recirculation” influent, was clarified secondary effluent. Three recirculation ratios, defined as the ratio of the recirculation influent to the fresh influent, were examined: 0 (no recirculation), 1 (50% of the flow is recirculation), and 3 (75% of the flow is recirculation). Each recirculation ratio was studied at three hydraulic loading rates.

Recirculation improved nitrification at all hydraulic loading rates. Improved nitrification with recirculation was due to the dilution of influent biodegradable organic carbon (BOD5) which occurs as a result of mixing secondary plant effluent with first stage effluent. An unexpected and operationally significant result was that extremely low concentrations of influent organic carbon did not improve nitrification.