bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transient Responses of Wastewater Treatment and Biomass Development in a Methanogenic Fluidized Bed
Authors: Furumai Hiroaki , Kuba Takahiro , Imai Tsuyoshi , Kusuda Tetsuya 
Published: May 2018

The objectives of this study are to develop a model which can express the characteristics of anaerobic treatment in a methanogenic fluidized bed reactor in non-steady states, and evaluate the usefulness of the model in which “active” biomass concentration is used as an index of bacteria concentration instead of traditional ones such as volatile suspended solids.
The treatment in the fluidized bed reactor started with biocoated synthetic zeolite as support material. The reactor was supplied with synthetic wastewater, a mixture of volatile fatty acids. An experiment on response was conducted according to changing stepwise the influent concentration. Batch experiments on activity were carried out under several steady state conditions, using a kind of volatile fatty acid as a substrate. Transient responses of water quality are investigated in relation to the growth of bacterial groups which decompose volatile fatty acids. Based on the results, a dynamic model is proposed, in which attached biomass is categorized into “active” biomass and inert organic matter. The transient response of substrate concentrations was clearly expressed by considering the growth of “active” biomass. It was impossible to explain the responses when VSS was regarded as the biomass concentration in the model.
A Basic Study of the Efficiency of Spiral Flow Aeration
Authors: Kasakura Tadao , Tomita Yoshiho , Matsubara Kiwamu , Kubo Atsushi 
Published: May 2018

The oxygen transfer efficiency of spiral flow aeration is affected by many factors, for example, the shape of aeration tank, the type of diffuser, the air flow rate and so on. The authors tried to determine the relationship between these factors and the efficiency of aeration. We found these factors were restricted by some independent variables, so we analyzed quantitatively the relationship between these variables and the efficiency of aeration based on data from the full scale experiments on spiral flow aeration using porous ceramic diffusers.
Regression equations show that the efficiency of the spiral flow aeration would be higher with a reduction of the air feed rate per tank volume and an increase of the total bubbling area of the diffusers. Other variables would not so greatly affect efficiency.
Wastewater Reuse Case Studies in the Middle East
Authors: Banks P. A. 
Published: May 2018

Within the past few decades the accelerating demand on natural resources to provide water for urban use, and the associated cost of meeting that demand, has led to an increased interest in the reuse of waste waters for municipal, agricultural, industrial and groundwater recharge purposes.
This paper reports upon the use made of effluent in some of the oil economies of the Middle East. It discusses the features of reuse in this particular context, the processes used and the standards adopted. Tabulated information and operational results are compared and the effect of reuse upon the local environment is commented upon.
Characterization of Polycyclic Aromatic Hydrocarbons (PAHs) by the Kinetics of Depuration in Bivalve Molluscs, Mercenaria mercenaria
Authors: Sato C. , Kim H. , Tanacredi J. T. 
Published: May 2018

The objectives of this study were to examine depuration aspects of polycyclic aromatic hydrocarbons (PAHs) in a hard-shell clam Mercenaria mercenaria, and to characterize PAHs by the depuration kinetics. In this investigation, clams were exposed to artificial sea water containing a mixture of eight PAHs (i.e., naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[a]pyrene) for 48 hours. The clams were then transferred into clean (PAH-free) artificial seawater for release, and sampled at predetermined intervals. The target PAHs were extracted from the clam tissue and quantified by a gas chromatograph equipped with a capillary glass column and FID.
The results revealed single- and multi-component release mechanisms which were described by single- and multi-stage first-order kinetics, respectively. Benz[a]anthracene and benzo[a]pyrene exhibited the single-stage depuration, while naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and chrysene showed the two-stage depuration.
Integrated Refinery Waste Management
Authors: Shieh Y.-S. , Sheehan W. J. 
Published: May 2018

In response to the RCRA land ban regulations and TC rule promulgated by the U.S. Federal Environmental Protection Agency (EPA) in 1988-1990, an Integrated Refinery Waste Management (IRWM) program has been developed to provide cost-effective solutions to petroleum industry customers. The goal of IRWM is to provide technology based remediation treatment services to manage sludges and wastewaters generated from the oil refining processes, soils contaminated with petroleum distillates and groundwater contaminated with fuels.
Resource recovery, volume reduction and waste minimization are the primary choices to mitigate environmental problems. Oil recovery has been performed through phase separation (such as centrifugation and filtration) and heating of heavy oils. Volume reduction is achieved by dewatering systems such as centrifuges and filter presses, and low temperature thermal treatment. Waste minimization can be accomplished by bioremediation and resource recovery through a cement kiln. In-situ vapor extraction has been applied to remove volatile organic compounds from the vadose zone in contaminated sites. Stabilization has been effective for soils contaminated with heavy metals and nonvolatile substances.
For the listed hazardous wastes generated from the refining process, a combination of liquid/solids separation and thermal treatment has been successfully applied. The sludge from the on-site ponds or continuous operations is pumped to a surge tank before heating, phase separation and volume reduction by a two-stage centrifuge system. The first stage horizontal centrifuge has effectively separated the solids from the liquid phase containing oil and water. The oil in the liquid phase is separated from the water in the second stage vertical centrifuge and is recycled back to the refinery for re-use. The water will be sent back to the wastewater treatment system for further treatment. Pretreatment of the wastewater may be required.
Photocatalyzed Degradation of Adsorbed Nitrophenolic Compounds on Semiconductor Surfaces
Authors: Dieckmann M. S. , Gray K. A. , Kamat P. V. 
Published: May 2018

Using semiconductor materials as photocatalysts to degrade hazardous organics has gained much attention in recent years. Colored compounds adsorbed onto semiconducting surfaces such as TiO2 or ZnO have been shown to be excited by visible light and to readily undergo degradation (Gopidas and Kamat, 1989). This same principle can be applied to the photo-induced destruction of colored pollutants such as nitrophenols. Since visible light can be used to initiate the photodegradation of colored pollutants, this type of semiconductor system offers a potentially efficient treatment process. The purpose of this research is to study the mechanisms involved in the photodegradation of nitrophenols by semiconductors.
Steady state diffuse reflectance photolysis studies indicate that TiO2, which exhibits semiconducting properties, gave the smallest half-life for photodegradation of 2,5-dinitrophenol. The metal oxides which acted only as support materials produced little photodegradation. Various nitrophenols are compared to study the effect of substituent nitro groups on rate of reaction. For example, 4-nitrophenol degradation has a half-life of 10 minutes while the half-life of 3-nitrophenol is 70 minutes. Also, an increase in the number of nitro groups decreases the rate of reaction. The half-life of mononitrophenols is on the order of an hour and dinitrophenols on the order of two hours while trinitrophenol still does not degrade to its half-life even after 8 hours of irradiation. Flash photolysis experiments with 4-nitrophenol in ethanol indicate the presence of a 420 nm transient species. Experiments in aerated and deaerated conditions show that the transient is an oxidation product and that it is not a triplet. Pulse radiolysis studies indicate that the transient is most likely a hydroxyl adduct of the parent compound. The presence of ZnO quenched the 420 nm transient.
Evaluation of Sludge Properties at an Activated Sludge Plant
Authors: Eriksson Leif , Steen Inga , Tendaj Marta 
Published: May 2018

Composition of pre-settled water, sludge properties in two different lines of an activated sludge plant, and suspended solids (SS) content in outgoing water were followed three times a week during one year. Sludge characteristics were: settling properties, residual turbidity, floc strength, filtration resistance, amount of extracellular polymers, microscope appearance and total length of filamentous organisms.
The outgoing SS could be related to residual turbidity and sludge volume. These factors depended on the floc structure and the filament length. These were determined by sludge load or sludge age, water composition and the hydrodynamic history of the sludge. On basis of these and earlier findings a general model for properties of flocs built by floc-forming organisms in activated sludge is proposed.
Kinetic Studies on a UASB Reactor Subjected to Increasing COD Concentration
Authors: Paula D. R. , Foresti E. 
Published: May 2018

This paper shows the response of a UASB reactor subjected to increasing influent COD concentrations.
The study was carried out using a 10.5 1 UASB reactor continuously operated during ten months, and fed with synthetic wastes prepared daily using glucose, ammonium acetate, methanol and nutrient solution. The. flow rate of 16 l.d−1 was held constant throughout the experiment, corresponding to a hydraulic retention time (θ) of 15.6 h. Four intermediate sampling ports besides the influent and effluent ones allowed a study of the reactor behaviour along its vertical profile.
For average values of the initial COD concentrations ranging from 1780 to 9700 mg.l−1, corresponding to volumetric loading rates (BV) of 2.7 to 14.8 kg COD.m−3. d−1, COD removal efficiencies varying from 98 to 80% were achieved.
It could be concluded that the step-increase of the influent COD affected the reactor performance in two different ways. First, the reactor could assimilate the shock loads due to the step-increase of the influent COD and BV beyond the transient periods following changes in the operation parameters. Second, the overall efficiency decreased gradually with the step-increase of the initial COD and BV.
Kinetic studies indicate that the overall kinetic parameters are probably affected by the step-increase of influent COD concentrations.
Anaerobic Treatment of Synthetic Sulfate-Containing Wastewater under Thermophilic Conditions
Authors: Visser A. , Gao Y. , Lettinga G. 
Published: May 2018

The anaerobic treatment of a sulfate-containing waste water using a UASB reactor was studied at 55 °C. As substrate, acetate and a mixture of acetate, propionate and butyrate were used. With acetate as substrate it was shown that sulfate reducers are capable of using acetate as substrate at 55 °C, and that, under the conditions applied, they even outcompete acetoclastic methanogens. Batch-activity measurements with the sludge revealed temperature optima for acetate, propionate and butyrate degradation of ± 56-59, &lt; 40 and 52-54 °C respectively.
After switching the substrate to a mixture of acetate, propionate and butyrate, the reactor pH dropped from 8.3-8.6 to 7.6-7.9 and the methane production recovered. After the establishment of a pseudo-steady state situation the part of COD removed by methane production and sulfate reduction was ± 60 and 40 %. Results of batch activity experiments showed that the methanogenic activity dropped sharply at pH ≥ 8 and ≤ 6 causing a predominance of sulfate reducers at pH ≥ 8.
Sediment Deposition in Storage Tanks
Authors: Saul A. J. , Ellis D. R. 
Published: May 2018

The use of storage tanks in sewerage systems has increased in recent years. The primary functions of such tanks are to attenuate flow and to retain pollutants within the sewer system. The size of the required storage volume is dependent on the purpose for which the tank is to be used but the end product of any design analysis is the definition of fixed volume of storage which has to be included as part of the sewerage system. The main problem is to provide storage and effective separation of gross and suspended solids without incurring poor self cleansing and associated high maintenance costs.
The work outlined in this paper involved the development of a laboratory computer controlled monitoring system for the purpose of flow visualisation and for the comparative assessment of the sediment deposition and removal performance of different geometric configurations of storage tank. These systems used sophisticated control procedures and the latter had the facility to generate a flow hydrograph of any shape and duration and to superimpose on this hydrograph a pollutograph of synthetic sediment, in this case crushed olive stone wood flour. Particular attention was focused on the optimum length to breadth ratio for a given storage volume, the configuration of the chamber floor - number, shape and gradient of dry weather flow channels and benching (gradient; the type of roof support and the effect of multiple storms on the redistribution of deposited sediment.
The results of the work illustrated that very complex flow patterns were established within the storage tanks as the flow hydrograph was discharged through the system and that these flow patterns governed the sediment settlement, re-entrainment and transport processes in the tank. The velocity distribution within each chamber was a function of tank geometry, the shape, volume, and duration of the inflow hydrograph and the throughflow setting.
The paper is concluded by a series of recommendations to aid the design of storage tanks.
Industrial Wastewater Treatment with Membranes - A United States Perspective
Authors: Cartwright P. S. 
Published: May 2018

Since the establishment of the U.S. Environmental Protection Agency more than 20 years ago, protection of the environment has steadily been moving up on the priority list of the American public. Concern over issues such as the ozone hole, the greenhouse effect, overflowing landfills, acid rain, destruction of the rain forests and over population have created an attitude of conservation and environmental responsibility throughout the country.
The united States Congress has passed the Pollution Prevention Act of 1990 which emphasizes “point-of-source” reduction, recycle or recovery.
The membrane separation technologies of microfiltration, ultrafiltration and reverse osmosis possess characteristics which make them attractive as recycle and recovery processes.
This paper details the testing requirements dictated by the specific applications and describes a number of case histories where membrane technologies have been evaluated for industrial wastewater treatment.
Genotoxicity of Organic Substances in Municipal Sewage and Its Ozonated Products
Authors: Ono Y. , Somiya I. , Kawamura M. , Uenishi K. 
Published: May 2018

Some organic substances contaminated in industrial wastewaters are not easily decomposed through biological treatment plant. In order to investigate the genotoxicity of the substances which remain in effluent from a municipal sewage treatment plant receiving industrial wastewaters, bacterial and mammalian assays were applied to the concentrated samples of secondary effluent. Ozonation was applied to decompose hard-biodegradable organic matters and to decrease its genotoxic intensity.
Genotoxicity was surveyed for the concentrated samples using umu test system which can detect the umuDC genes that are known to cause error-prone repair. Positive results were observed in the case of Sep-pak-methanol extracts of secondary effluents with microsomal activation. Results of umu test showed negative in the ozonated samples of the effluent. Genotoxic substances in secondary effluents were decomposed by ozone into non-genotoxic substances.
The concentrated sample was fractionated by gel chromatography using Sephadex LH-20 which can separate the molecule in the range from 100 to 5,000. A fraction of the effluent was determined as positive in umu test. The substances were detected in the range of over 5,000 molecular size.
A UV/Oxidation Technology Demonstration to Treat Ground Water Contaminated with VOCs
Authors: Topudurti K. 
Published: May 2018

This paper presents the field demonstration results of the ultraviolet radiation (UV)/oxidation technology developed by Ultrox International, Santa Ana, California. The technology was demonstrated at the Lorentz Barrel and Drum (LB&D) site in San Jose, California, under the United States Environmental Protection Agency's Superfund Innovative Technology Evaluation program.
The UV/oxidation technology uses UV radiation, ozone, and hydrogen peroxide to oxidize organic contaminants present in water. At the LB&D site, this technology was evaluated in treating groundwater contaminated with volatile organic compounds (VOCs). The Ultrox system achieved VOC removals greater than 90 percent. The majority of VOCs were removed through chemical oxidation. However, for a few VOCs, such as 1,1,1-trichloroethane (1,1,1-TCA) and 1,1-dichloroethane (1,1-DCA) stripping also contributed toward removal. The treated groundwater met the applicable discharge standards for disposal into a local waterway at 95 percent confidence level. There were no harmful air emissions from the Ultrox system into the atmosphere.
Behaviour of Micropollutants in Soils Amended with River Cleaning out Sludge in Northern France
Authors: Gandais V. , Marchandise P. 
Published: May 2018

Thisstudyis aimed at determining the fate of some heavy metals and hydrocarbons in soils amended with sludge from river cleaning out. Northern France has been chosen for the experiment because it is a heavily industrialized region where contamination by micropollutants has been very acute for many years. Several French laboratories are associated in this joint project which is partly sponsored by the Ministry of Environment and Artois-Picardie Water Agency.
The parcel of land studied has a surface area of 100m2. It has been instrumented with Chamberland candles in order to get water for micropollutants analysis, tensiometers and a neutronic probe so as to collect informations on the hydric state of the soil. Once instrumented the parcel has been spread with sludge from river cleaning out.
The main objective is to obtain an estimation of the fluxes of micropollutants and to evaluate the respective proportions of infiltration and drainage.
A lab study based on lysimeters is carried out together with the field study. The field study will last at least 2 years while the lab study will be going on for a year.
Sludge Disposal from an Island Community
Authors: Gross T. S. C. , Cohen R. R. 
Published: May 2018

The small island of Jersey is served by a single wastewater treatment plant at Bellozanne. Since its inception some 30 years ago the sludge produced has been used on agricultural land.
Inevitably there are circumstances which prevent this happening without interruption, eg, poor weather, or seasonal demand. On these occasions, the island has no other disposal option to fall back on. Furthermore, concerns over the practice have created a perception that it might be doing harm to the ‘quality' of the farm produce.
The responsible body, the Public Services Department, formulated a flexible, multiple option solution and commissioned Halcrow to engineer the capital works. The works centre around a thermal drying plant using biogas produced by the digestion process as the main fuel. Waste heat is recovered for digester heating making the total process potentially self sufficient in energy. At the same time, the bulk of the product is reduced considerably, providing an easily transported material with potential for use directly on the land as a fertilizer substitute or as a low grade fuel.
Farfrom being a disposal problem requiring manpower and expense, sludge will soon be regarded by the States of Jersey as a valuable resource with a revenue potential.
Bathing in the Rain - The Use of Mathematical Models for Storm Water Management to Achieve Bathing Water Quality (The Fylde Coast-NW England)
Authors: Head P. C. , Crawshaw D. H. , Dempsey P. , Hutchings C. J. 
Published: May 2018

One of the major problems in trying to design wastewater treatment schemes to protect bathing water for coastal communities with combined sewerage systems, is to ensure that discharges of storm water do not prejudice compliance with the requirements of the EC Bathing Water Directive. In order to develop an appropriate storm water management strategy for the Fylde coast it was necessary to integrate a number of mathematical models simulating the hydraulic behaviour of the sewerage system and the dispersion of discharges in the receiving waters.
From the sewerage system modelling it was apparent that frequent discharges of storm water to the bathing waters could only be avoided by the provision of considerable additional storage in the system. By means of a suitably calibrated simplified sewer model it was possible to investigate the volumes of storm water generated by a 15 year record of local rainfall when different amounts of extra storage and different pumping regimes were employed. The results from these investigations were used to determine the probable concentrations of faecal bacteria in the coastal waters for each of the 15 bathing seasons and determine the percentage of time for which faecal coliform concentrations exceeded the Bathing Water directive standards for the model grid cells representing the identified bathing waters. As a result of the extensive integrated modelling programme for the Fylde coast it has been possible to design a base flow and storm water management system which should maximize the flow passed forward for treatment whilst also ensuring that there is just sufficient storage to ensure protection of the towns from flooding and the compliance of the beaches with the Bathing Water Directive standards.
Biological Phosphorus Removal in Fixed Films Reactors
Authors: Franci Gonçalves R. , Rogalla F. 
Published: May 2018

Possible procedures to achieve biological phosphorus removal in a fixed film reactor are discussed and the feasibility of phosphorus removal process in a fixed film reactor under continous flow is demonstrated. The behaviour of an upflow aerated filter operating under continuous feed and alternate aerobic/anaerobic conditions is analyzed. The influence of the duration of anaerobic and aerobic contact periods and of organic substrate loadings on the phosphorus removal process is verified. During the anaerobic state, the longer the duration, or the higher the substrate load, the better the phosphorus release and consequently the higher the uptake in the aerobic phase. The excess of accumulated phosphorus in the aerobic phase over released phosphorus in the anaerobic phase approaches 33 %. For each mg of phosphorus released, 5 mg filtered COD are consumed.
Continuous phosphorus removal on two biofilters in series was performed by alternating aeration conditions, always introducing the influent to the anaerobic reactor.The tests carried out on laboratory scale showed that this system carrys out complete nitrification and removal of 80% of the phosphorus with a maximum hydraulic retention time of 5 hours. The hydraulic retention time and the residence time of the biomass in the reactor are independent and, therefore, the time the bacteria are exposed to alternate A/O conditions can be optimized. The very low concentrations of suspended solids in the effluent of the biofilter enable residual levels below 1 mg PO4-P/l to be obtained. Further investigations are carried out on full scale and to introduce denitrification in the same reactor.