bluuebunny/crossref_metadata_2025 huggingface dataset:
Solidification of Metal Finishing Slurry with Cement
Authors: Cláudio J. R.
Published: May 2018

From July, 1986 to March, 1987, the author developed laboratory, tests on cementation of electroplating wastewater treatment sludges. Perfomed at the laboratories of Escola Politécnica of the University of São Paulo and of CETESB, tests were conducted with three types of cement produced in Brazil: CPC - Portland Cement, POZ pozzolanic cement and CAF - blast furnace cement. The tests had the following steps:–characterization of electroplating industry wastewater treatment sludge and study of the sludge - cement mixtures;–preparation of sludge - cement mixtures with 3 different water/cement ratios;–measurements of mixture consistency with Casagrande soil mechanics equipment;–determination of leaching quality and resistance to compression of solidified specimen at 3 ages;–analytical determination in the sludge-cement mixture;–test for solubility in water;–analytical determination of cyanide and heavy metals in the cure water of specimen.

Results showed that solidification with cement is an efficient technology for the fixation of toxic metal ions such as Cd, Hg and Pb and other metals such as Cr, Ni, Cu or Zn present in large concentrations in electroplating wastewater treatment sludges. With the only exception of Al+++ the other metallic ions determined in the leachate showed concentrations below drinking water standards. As to mechanical resistance after 90 days, the sludge - cement mixtures presented a performance similar to that of structural concrete.
Rhineland on the Way to its Thousandth Anniversary or Water-Administration in the Next 100–200 Years
Authors: baron van Tuyll van Serooskerken E. H.
Published: May 2018

An inventory is made of the effects of sea level rise and expected climatic change on the level of the district water authorities in the Netherlands and especially the “hoogheemraadschap” of Rhineland in the next 100-200 years. Special attention is paid to the effects on land utilization, coastal defence and water control.

The first is hard to describe by lack of research, the second can already be determined in terms of cost; the third can be described in its effects on brackishness and water provision with indication of policies and measures to be taken.

Preliminary conclusions are that larger efforts on coastal defence - even with present techniques - will be a realistic answer in terms of cost. The foreseen increase of brackishness in area and salt concentration, will give a significant extra need for fresh water.

High cost and even higher risks have to be expected with regard to measures to neutralize the effects of a water surplus in winter and a growing water shortage in (late) summer, while the cost will further grow. Because of the effect a larger area must be drained off and water has to be raised higher as the Netherlands will sink in relation to the North Sea.
A Study of the Eutrophication of North Lake, Western Australia
Authors: McDougall Bryn K. , Ho Goen E.
Published: May 2018

North Lake is an urban freshwater wetland, and like other wetlands in the Perth metropolitan region, Western Australia, has become nutrient enriched, with the accompanying problems of algal blooms, decay, odour, infestation with midges and aesthetic deterioration. A study of the water quality of the lake was undertaken to quantify the variation of phosphorus, nitrogen and chlorophyll-a, and the sediments store of nutrients and their release with pH. The dominant algae in the lake, Microcystis, was found to be limited in growth by nitrogen because of the high availability of phosphorus (> 0.1 mg/l), and likely by light because of self-shading (chlorophyll-a > 0.3 mg/l). Sediments released a substantial amount of nutrients as pH rose above 8.5. Together with a parallel study of the nutrient budget of the lake, a management strategy has been derived to overcome the problem of nutrient enrichment that could be applied to other wetlands in the metropolitan region.
Sewage-Related Impact on Kuwait's Marine Environment – A Case Study
Authors: Al-Muzaini S. , Samhan O. , Hamoda M. F.
Published: May 2018

This paper overviews the marine environmental impacts associated with Kuwait's liquid wastes, whose volume has grown considerably over the last two decades and is expected to grow further. The characteristics of local sewage, its collection, handling and treatment practices, and routes of input into the local marine environment are described. Realized or potential environmental impacts are discussed.

Sewage discharge has been found to exert different impacts on Kuwait's marine environment, ranging from fish kills and localized smothering of benthic organisms and microbial pollution to potential wider impacts on overall marine productivity. These impacts are due to a combination of unique local environmental conditions (e.g., high ambient air temperatures, high rates of dust fallout and creeping sands, and prevalence of wide intertidal flats) and specific problems in the sewage works (high strength and anaerobicity of sewage, lack of alternative routes from peripheral pumping stations to a central treatment plant that is biochemically overloaded, emergency discharge through short outfalls onto wide intertidal flats, and discharges from premises that are not connected to a sewerage scheme). Recommendations to alleviate these impacts are summarized.
Heavy Metal Removal Using Bound Macrocycles
Authors: Izatt R. M. , Bruening R. L. , Borup M. B.
Published: May 2018

Aza macrocycles bound to silica gel beads were found to selectively remove heavy metal cations such as Pb2+, Cd2+, Ag+, and Hg2+ from aqueous solutions. These bound macrocycles have a virtually infinite selectivity of binding with heavy metals over alkali and alkaline earth cations. The material is very stable and can be reused hundreds of times. Columns may be regenerated using an acidic eluent solution. Equilibrium constants were determined by column tests. Removal of heavy metals was demonstrated in bench scale tests using a synthetic contaminated water and in pilot scale tests using a naturally contaminated river water. Heavy metal concentrations could be effectively reduced to the µg/L level using the process.
Present Situation and Problems Related to Marine Oily-Water Separating Techniques
Authors: Watanabe K. , Yamanouchi H. , Ueta Y. , Nagata O.
Published: May 2018

Merchant ships are required to be provided with oily-water separating equipment that meets the requirements of the International Performance Testing Standard A. 393 (x) prescribed by the International Maritime Organization (IMO), where the discharged oil contents of the effluent measured at the outlet of the equipment are controlled to 15 ppm or 100 ppm according to the classification of ships by gross tonnage. However, investigations are being undertaken to find international solutions centring on the Marine Environment Protection Committee (MEPC) of IMO to improve the not-necessarily-satisfactory-service-performance of oily-water separating equipment, as is evident in cases reported overseas. In this study, the actual service performance of the existing oily-water separating equipment in Japan was investigated and a study on new oily-water separating techniques was conducted with expertise acquired as outlined below.

In view of the fact that the engine room bilge in an actual ship contains suspended solids (SS), detergents and other materials in addition to fuel oil and lubricating oil, it is difficult to clear the discharged oil control requirement of 15 ppm at all times, inasmuch as the existing oily-water separating system relies only on a gravitational separation system comprising multiple parallel plates and a filter-type coalescer. The newly developed oily-water separating mechanism relying on oil flocculation and froth flotation has displayed its usefulness for oily water containing oil particles and suspended solids with a particle size smaller than 10 µm, and thus is promising for application to oily-water separating equipment to be designed for clearing the 15 ppm discharge requirements.
Identification of Non-Biodegradable, Hydrophilic, Organic Substances in Industrial and Municipal Waste Water Treatment Plant-Effluents by Liquid Chromatography-Tandem Mass Spectrometry (LC/MS/MS)
Authors: Schröder H. Fr.
Published: May 2018

Effluents of biological waste water treatment plants containing high concentrations of non-biodegradable substances measured as COD (chemical oxygen demand) were analyzed by gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). GC/MS could detect any relevant compound because of involatility of these substances. LC/MS/MS was able to give molecular weight information without any separation bypassing analytical column. Daughter- and parent-ions formed by MS/MS gave structural information by fragmentation under CID-conditions (collisionally induced dissociation) even for UV-non-detectable chromophor missing substances.

Metabolites and anthropogenic, non-biodegradable substances such as polyether, nonionic alkyl-and arylsurfactants and benzene-sulfonic acid could be detected and identified after C 18 column separation and without any prior separation, bypassing column.

Analysis without any separation could be done within a few minutes up to an hour, column separation lasted 10 to 100 fold longer.
A Stationary Packer System for Layerwise Groundwater Sampling in Monitoring Wells – Technique and Results
Authors: Rödelsperger M. , Rohmann U. , Frimmel F.
Published: May 2018

A sampling device was designed as a stationary equipment for deep monitoring wells in order to obtain representative groundwater samples from different layers of the aquifer. The device consists of several packer units which can be combined at variable distances, allowing adaption to the local conditions of the aquifer and of the well. The pumps are situated below the groundwater table. Each of the drawing tubes ends between two packers at the concerning depth. Experimental results demonstrate the importance of the application of a stationary packer system instead of a mobile doublepacker in deep aquifers of inhomogeneous structure. Examples of concentration profiles obtained from layerwise groundwater sampling are given and a technique for selective groundwater discharge is described.
Regulatory Requirements for Pulp and Paper Mill Effluent Control: Scientific Basis and Consequences
Authors: Folke J.
Published: May 2018

The Ministers' Declaration from the 2nd North Sea Conference recommended a goal to be set to diminish the discharge of hazardous substances via rivers by 50% over the next 10 years, e.g. to diminish the discharge of persistent halogenated compounds from pulp and paper mill effluents. The Paris Convention adopted this recommendation later.

Based on a study conducted for the EEC Commission, we have arrived at the following conclusions to fulfil this goal.

For historic reasons the regulation of the pulp and paper industry includes some parameters which may not be the most appropriate ones, e.g. BOD5 and AOX. To regulate the bleached pulp mills by AOX/TOC1 is not recommendable. PCDD/PDDFs are very difficult to regulate at present. Regulation of polychlorinated phenolics (PoCPs) in the effluent may prove to be a valid indirect measure of TCDD-equivalents, but this has yet to be proven. To ensure sufficient removal of hazardous compounds, we recommend that standards for TSS be stringent, as the major fraction of hazardous compounds is associated with suspended solids (including PoCPs and PCDD/PCDFs). Effluent control should be based on pH, COD (Chemical Oxygen Demand using dichromic acid), TSS (total suspended solids) and PoCPs.

At present there are not sufficient data available to establish a regulation based on these parameters. So, further data should be obtained.
Effect of NSSC Spent Liquor on Granule Formation and Specific Microbial Activities in Upflow Anaerobic Reactors
Authors: Guiot S. R. , Lavoie L. , Hawari J. A. , Samson R.
Published: May 2018

This study was conducted to evaluate the capability of sulfonated lignin (S-lignin) to induce the flocculation of anaerobic sludge in upflow wastewater treatment. Two upflow anaerobic sludge bed-filter (UBF) reactors fed with a synthetic sugar waste were operated at a specific loading rate of 0.6 to 1.8 g of chemical oxygen demand (COD) per g of volatile suspended solid (VSS) per day (d). One of these reactors was stepwise supplemented with a spent liquor rich in S-lignin from a neutral sulfite semi-chemical (NSSC) pulping plant to reach an addition rate of 0.17 g S-lignin/g VSS d; 50 % of the S-lignin was adsorbed onto the biomass. This resulted in pre-granulation of the anaerobic sludge: 50 to 60% of the biomass was in particles > 0.3 mm versus 70 to 80% with a size < 75 µm in the control reactor. In addition, the S-lignin supplementation slightly enhanced the specific metabolic activities of the biomass. Calcium ion addition following the S-lignin treatment enhanced the stability and the density of the aggregates.
Treatment of Bleach-Plant Effluents with Membrane Filtration and Sorption Techniques
Authors: Ekengren Ö , Burhem J.-E. , Filipsson S.
Published: May 2018

Laboratory experiments have been run with the combination of ultrafiltration (UF) and sorption techniques/reverse osmosis (RO).

The use of negatively charged membranes improved both the filtration capacity (flux) and the rejection of organochlorine compounds.

The combination of UF and RO used to treat retention in the caustic extraction stage showed high removal of COD, AOX and chloride ions (98.8 - 99.9 %). The content of AOX in the RO-permeate was 0.08 g per ton pulp.

The ultrafiltration of three different total bleachery effluents showed a COD removal of 55-60 % and a AOX removal of 65-75 %. The decrease in toxicity was about 50 % and the removal of substances with a bioaccumulation potential was around 90 %.

The treatment of this UF-permeate with a weak-base anion exchanger gave even higher removal efficiencies especially for the chlorophenolic compounds (>93 %), and the toxicity decreased 5 times (Microtox). The sorbent did not show any remarkable loss in removal efficiency during the 48 loading and reactivation cycles.

When treating the total bleachery effluents the combination of UF and RO also showed high removal efficiencies.

It is not meaningful to make a cost estimation before these combinations have been studied for longer periods, on larger scales and with a wide range of effluents.

The problem of the final destruction of the pollutants which have been removed remains to be solved.
Practical Experience with Biological Removal of Phosphorus from Pulp and Paper Mill Effluents
Authors: Meloni E.
Published: May 2018

The nutrient situation and nutrient removal policy in Finland are discussed and the principles of biological phosphorus removal are outlined.

The approach of Metsä-Serla Oy to the nutrient problem is described: Metsä-Serla has been studying biological phosphorus removal since 1987. At the beginning of 1989 plant-scale experiments were started at the Kirkniemi paper mill. The results have been promising, the highest removal rates obtained being over 90 %.

Experimenting with biological phosphorus removal will be started at all Metsä-Serla's activated sludge plants (five in all) in the near future.
Treatment Technologies for Organochlorine-Containing Sludges and Concentrates from External Treatment of Pulp and Paper Wastewaters
Authors: Almemark M. , Finnveden G. , Frostell B.
Published: May 2018

Literature data and results from current Swedish research have been used to compile characteristics of and disposal methods for sludges and concentrates from external treatment of wastewaters from the pulp and paper industry. Very little sludge from aerobic lagoon treatment in Sweden is handled, and most of the solids are deposited in the receiving waters. In North America, Finland and Japan, where activated sludge treatment is used to a great extent, sludge handling is an important part of kraft mill effluent treatment. Typically, 5-15 kg of dry solids has to be handled per ton of pulp with a process discharge of 15-20 kg of BOD5/t90- For chemical coagulation, the amounts of sludges produced are higher, typically 40-80 kg dry solids/t90. Especially in Japan, chemical coagulation is used to a great extent. Laboratory and pilot- plant experiments with Ultrafiltration of alkaline stage and total bleach plant effluents suggest that concentrates with a total solids content of approximately 20 and 50 kg dry solids/t90 are produced. The concentrations of organochlorine compounds in sludges and concentrates have not hitherto been well documented, and nor have environmental effects of different disposal methods. Chlorinated phenols, catechols and guaiacols have been found in variable concentrations; chlorinated dibenzodioxins and furans have also been detected.

Vacuum filters and especially belt filter presses have been used to dewater sludges. Typical dry solids concentrations achieved vary from 20-35 % for primary sludges to 15-20 % for secondary sludges. Anaerobic digestion may be applied before dewatering of sludges, and methane yields of 200-400 1 CH4/kg VSrem have been reported. Sludge has been disposed of in landfills or incinerated. Leachates from landfilling of pulp and paper industry sludges may contain high levels of soluble organic material, but available information suggests that organochlorine compounds do not leach to a substantial extent. Incineration of pulp mill sludges and concentrates seems to be an increasingly attractive method.
Kinetics of Nitrification Denitrification Biological Excess Phosphorus Removal Systems–A Review
Authors: Wentzel M. C. , Ekama G. A. , Marais G. v. R.
Published: May 2018

This paper reviews developments in the kinetics of biological excess phosphorus removal (BEPR) in nitrification denitrification BEPR (NDBEPR) activated sludge systems – development of polyp organism enhanced cultures, their kinetics, simplification of the kinetics for enhanced cultures under constant flow and load conditions, extention of the simplified model to mixed culture NDBEPR systems under constant flow and load conditions. The next stage will be the development of a general NDBEPR kinetic model valid for cyclic flow and load. Before such a model can be established, an important problem needs to be resolved – the kinetics of denitrification in NDBEPR systems; recent studies show that the specific denitrification rate due to slowly biodegradable COD is significantly higher in NDBEPR than in nitrification denitrification (ND) systems.
Combined Chemical and Biological Removal of Phosphate in Activated Sludge Plants
Authors: Lötter Laurraine H.
Published: May 2018

Biological phosphate removal has been achieved in nutrient removal plants in Johannesburg by generating the required substrate for the process. Substrate generation has taken place by primary fermentation and subsequent elutriation. This technique, coupled with control of nitrate return to the anaerobic zone, has allowed phosphorus to be removed almost exclusively by biological means in plants designed for nutrient removal. However, operational problems with primary sedimentation tanks being used for fermentation, for which they were not designed, necessitated the occasional use of chemicals in the Northern Works plant.

Contrary to current literature, the addition of ferric sulphate to this plant resulted in inhibition of polyphosphate storage; the cornerstone of the biological process.

Laboratory batch studies revealed that iron-treated activated sludge showed a lower propensity for ferric phosphate precipitation than an untreated sludge. These laboratory studies were borne out by practical experence on two extended aeration plants, not designed for nutrient removal. The performance of these plants with different chemicals is discussed and possible reasons are advanced for some of the plant observations.
Phosphorus Fractionation of Activated Sludges from Modified Bardenpho Processes with and without Chemical Precipitant Supplementation
Authors: de Haas David W. , Greben Harma A.
Published: May 2018

The natural occurrence of chemically precipitated phosphate in activated sludge (AS) has been hypothesized for over two decades and deserves fresh attention in view of the increasingly common practice of chemical addition to modified AS systems to achieve P removal. In this study, orthophosphate extracted from AS of modified Bardenpho plants could not be accounted for on the basis of polyphosphate interferences. In a plant not dosed with chemicals at least 14 mg P/g VSS were therefore formed by natural precipitation reactions while an identical plant dosed with ferric sulphate showed at least 37 mg P/g VSS to be of this fraction. A plant dosed with alum and receiving wastewater of mainly industrial origin contained up to 8 mg P/g VSS as chemical precipitate which was over half the total P content of that sludge. Restraint in dosing chemicals is suggested to prevent unnecessary suppression of the biological mechanism of P removal. Ferrous sulphate dosing may be superior to that with ferric sulphate Since the latter apparently causes poly P hydrolysis. Complex interactions between iron, ortho P and biomass are indicated. Furthermore, iron-ortho P complexes in mixed liquor supernatant may be unreactive in the colorimetric ortho P assay.
Development of New Nitrogen Removal System Using Nitrifying Bacteria Immobilized in Synthetic Resin Pellets
Authors: Tanaka Kazuhiro , Tada Minoru , Kimata Takashi , Harada Shouji , Fujii Yuhko , Mizuguchi Tamotu , Mori Naomichi , Emori Hiroyoshi
Published: May 2018

A newly developed process applying a technique of microorganism immobilization to biological nitrogen removal is reported. Nitrifiers immobilized in 2 to 3 mm diameter polyethylene-glycol resin (Nitrifying pellets) are mixed with activated sludge in the nitrification tanks to promote quick nitrification. Due to the high nitrifying activity of the pellets, nitrification of municipal wastewaters is completed within a few hours. This paper introduces the synthetic polymer and immobilization method suited to nitrifiers, the conditions for pellet fluidization, the activity of nitrifying pellets and its treatment performance as a nitrogen removal process.
Enhanced Nutrient Removal in Porous Biomass Carrier Sequencing Batch Reactor (PBCSBR)
Authors: Shin Hang-Sik , Park Hung-Suck
Published: May 2018

An investigation was made theoretically and experimentally on the porous biomass carrier sequencing batch reactor (PBCSBR) for enhanced nutrient removal. Biomass hold-up increased with incoming organic substrate concentration and held in attached and entrapped conditions. The behavioural patterns of organic carbon, nitrogen and phosphorus in PBCSBR were similar to the control SBR reactor. Nitrogen transformation and/or removal was simultaneous and stoichiometric and could be quantified by the stoichiomelric relationship of nitrification/denitrification based on the consumed alkalinity. Phosphorus removal increased with biomass concentration and phosphorus release. Higher biomass and favorable operation mode in PBCSBR were conducive to enhanced nutrient removal.
First Practical Experiences with Submerged Rope-Type Bio-Film Reactors for Upgrading and Nitrification
Authors: Lessel T. H.
Published: May 2018

The upgrading and nitrification was required for the waste water treatment plant in Geiselbullach. As space for more aeration tanks was not available, the possibility of increasing the MLSS by the use of submerged bio-film reactors was tested in a half technical scale pilot plant with three different reactor materials. Each tested reactor material caused a significant increase of MLSS and the nitrification reaction. The rope-type material was selected for the practical application, as it had not the same disadvantages of the other tested systems, which proved operational problems.

After one year of continuous operation for nitrification in the full scale plant the influences on the biomass characteristics were investigated. Design criterias and details and operational data are reported.
A Knowledge-Based Framework for the Diagnosis of Sludge Bulking in the Activated Sludge Process
Authors: Chan W. T. , Koe Lawrence C. C.
Published: May 2018

Despite advances in the understanding of the activated sludge process for treating wastewater, the operation of an activated sludge process plant - in particular, the detection, diagnosis and remedy of operational problems - still involves a significant amount of qualitative knowledge derived from empirical observations. Expert systems can be of assistance to plant operators in problem diagnosis by automating the problem-solving behavior of human experts and retrieving the appropriate chunks of qualitative knowledge from a large collection of such knowledge as the context of the problem dictates. A new generation of expert systems shell delivers better performance by providing (i) an object-centred framework with interesting computational properties to organize the considerable amounts of information about the physical world, (ii) flexible, context-dependent and programmable inference strategies to better model the problem-solving behavior of human experts, (iii) a reliable means of integrating numeric and symbolic computation, and (iv) a means for the expert system application to couple its inference procedure with its ability to interact with events in the real world through sensors and actuators. A prototype expert system employing a new generation expert system shell has been developed for diagnosing the sludge bulking problem in the activated sludge process. The paper discusses the knowledge representation scheme employed in the prototype, which is general enough to be extended to cover other operational problems occurring in sewage treatment plants. A study was performed to validate the knowledge in the prototype by comparing the conclusions of a panel of human experts reported in the literature with those of the prototype in response to a wide range of operating conditions. The study shows close agreement between the two sets of conclusions.
Role of Glycogen as an Intracellular Carbon Reserve of Activated Sludge in the Competitive Growth of Filamentous and Non-Filamentous Bacteria
Authors: Matsuzawa Y. , Mino T.
Published: May 2018

Activated sludge mixed cultures were cultivated with a glucose containing substrate in order to investigate the relationship between the feeding pattern (continuous or intermittent feeding) and the glycogen reservation capacity of activated sludge. An experimental method to measure the maximum capacity of glycogen reservation in the sludge was developed. Sludge with higher glycogen reservation capacity has an ability to synthesize glycogen faster, which ensures the higher glucose uptake. Therefore, sludge which has high glycogen reservation capacity becomes predominant in intermittently fed reactors. When the feeding pattern was changed from continuous feeding to intermittent feeding, a filamentous bacterium, Type 1701, started to decrease and a gram positive tetrad coccus became predominant. When the feeding pattern was returned to continuous feeding, Type 1701 re-appeared. Type 1701 has lower glycogen reservation capacity than the tetrad coccus. Therefore, the former cannot dominate over the latter in intermittently fed reactors.
Isolation of Microorganisms Capable of Lysing the Filamentous Bacterium, “Type 021N” (Studies on Lytic Enzyme against the Filamentous Bacterium, “Type 021N”, Screening Studies)
Authors: Yaguchi J. , Chigusa K. , Ohkubo Y.
Published: May 2018

A study was carried out to isolate the microorganisms capable of lysing the filamentous bacterium “type 021N” from activated sludge, compost, soil, and bark samples. The first screening for the lytic microorganisms was achieved on the agar plates containing heat-killed 021N filaments. The colonies which were surrounded by clear lytic zones were picked up and incubate further on the plates containing living 021N filaments. 67 strains capable of forming lytic zones against living 021N filaments were obtained and assayealytic activities by a turbidity method. Of these strains, No. 504 strain from soil, which was identified as Xanthomonas maltophilia, exhibited the most active and widest lysis range on any strain of 021N. No inducing substrate like 021N filaments was needed for the production of a lytic enzyme by No. 504 strain. The strain No. 504 may be expected to be a useful bacterium for the prevention and control of the filamentous bulking caused by 021N.
Population Dynamics of Phenol Degrading Microorganisms in Activated Sludge Process under the Stress of Phenolic Wastewater
Authors: Okada M. , Nakamura T. , Ito H. , Murakami A.
Published: May 2018

The process to gain and lose phenol degrading activity of activated sludge under different stress of phenol was studied by three types of operations, i.e. continuous flow reactor, aerobic SBR, and anaerobic/aerobic SBR under two types of loads, i.e. elevating and constant loads. The higher activity and tolerance under the higher concentration of phenol was gained in activated sludge of aerobic SBR under the constant high load. The higher phenolic stress, i.e. mixed liquor concentration of phenol, at the beginning of batch cycles seemed to increase the activity. Constant and low phenolic stress in continuous flow reactors and elevating load in SBR, however, could not build up tolerance and the higher degrading activity under the higher concentration of phenol. SBR operations which are able to give appropriate phenolic stress on activated sludge, even under the same daily loading of phenol as continuous flow reactor, would be preferable to build up and maintain the activity and to ensure stable operation of wastewater treatment even under shock loading. The degrading activity of activated sludge may be gained mainly by the increase in the ability of bacteria to degrade and tolerate phenol and not by the increase in population.
Denitrification Kinetics in Biological Nitrogen and Phosphorus Removal Activated Sludge Systems Treating Municipal Waste Waters
Authors: Clayton J. A. , Ekama G. A. , Wentzel M. C. , Marais G. v. R.
Published: May 2018

Using plugflow anoxic reactors and batch tests, an experimental investigation was undertaken into the kinetics of denitrification in nitrification denitrification biological excess phosphorus removal (NDBEPR) systems. It was found that (1) in the primary and secondary anoxic reactors, the specific rate constant for denitrification associated with the utilization of slowly biodegradable COD (SBCOD) was respectively 2½ and 1½ times higher than in these reactors in nitrification denitrification (ND) systems and (2) in the primary anoxic reactor, the rapid rate of denitrification attributable to readily biodegradable COD was absent. The increased rate is hypothesized to be due to a stimulation in the active sludge mass of an increased rate of hydrolysis of SBCOD in these anoxic reactors of the NDBEPR system apparently induced by the presence of the anaerobic reactor in these systems.
Computer Aided Design of Sequencing Batch Reactors Based on the IAWPRC Activated Sludge Model
Authors: Oles J. , Wilderer P. A.
Published: May 2018

A modified version of the IAWPRC activated sludge model was developed to describe the performance of laboratory and pilot scale Sequencing Batch Reactors (SBR). Changes of COD, ammonia and NOx during the SBR process cycle could be reliably predicted after the model parameters were adapted to SBR conditions. Most promising process strategies could be identified with the aid of a simulation program.
The Influence of Glucose Supplement on the Degradation of Catechol
Authors: Hwang Ping-Chih , Cheng Sheng-Shung
Published: May 2018

A series of batch Biochemical Methane Potential(BMP) tests and two parallel Upflow Anaerobic Sludge Bed(UASB) processes were conducted to investigate the influence of glucose supplement en the degradation of catechol. The substrate inhibition of catechol caused by thermal shock, restart or other operating problems was also studied. The results showed that the glucose supplement could accelerate the degradation rate of catechol, and the effect was more pronounced in the higher concentration range. The mechanism so-called cosubstrate utilization and the anaerobic metabolic pathway of catechol were proposed to explain these symptoms. Data of both batch tests and UASB processes indicated that high concentration of catechol did inhibit the bioactivity of anaerobic microbes. Operation strategy of effluent recirculation could maintain appropriate in-tank concentration to promote the high bioactivity in the reactors. The critical concentration of the highest degradation rate was estimated with a modified Haldane equation derived from the batch BMP data. Low temperature could also contribute inhibition to the microbes, the temperature factor θ with a value of 1.093 estimated from the batch data indicated that anaerobic microbes were very sensitive to the temperature change. The low bioactivity and catechol accumulation were observed during the restart period. It was suggested that lower volumetric loading should be applied in order to resume the bioactivity and to restart the reactor.
Application of Biofilm Kinetics to Anaerobic Fixed Bed Reactors
Authors: Gönenç I. E. , Orhon D. , Beler Baykal B.
Published: May 2018

Two basic phenomena, reactor hydraulics and mass transport through biofilm coupled with kinetic expressions for substrate transformations were accounted for in order to describe the soluble COD removal mechanism in anaerobic fixed bed reactors. To provide necessary verification, experimental results from the long term operation of the pilot scale anaerobic reactor treating molasses wastewater were used. Theoretical evaluations verified by these experimental studies showed that a bulk zero-order removal rate expression modified by diffusional resistance leading to bulk half-order and first-order rates together with the particular hydraulic conditions could adequately define the overall soluble COD removal mechanism in an anaerobic fixed bed reactor. The experimental results were also used to determine the kinetic constants for practical application.

In view of the complexity of the phenomena involved it is found remarkable that a simple simulation model based on biofilm kinetics is a powerful tool for design and operation of anaerobic fixed bed reactors.
A Fed-Batch Technique to Evaluate Biodegradation Rates of Inhibitory Compounds with Anaerobic Biofilms Attached to Granular Activated Carbon
Authors: Fox P. , Suidan M. T.
Published: May 2018

Adsorption kinetics render measurements of substrate utilization rates in biofilms attached to adsorbing materials difficult. A fed-batch technique which maintains a constant concentration of substrate in the presence of biomass attached to granular activated carbon (GAC) was developed to measure biological kinetics independent of adsorption kinetics. The fed-batch technique used pre-adsorbed substrate on GAC as a source of substrate. During the experiment, the mass of substrate that is biodegraded is negligible when compared to the large mass of adsorbed substrate. Near equilibrium adsorption phenomena maintains the concentration of substrate constant throughout the experiment and eliminates mass transport resistance within the biofilms. Substrate utilization rates were measured at a specific substrate concentration by monitoring methane gas production rates. Samples of GAC with attached biomass were removed from two expanded-bed anaerobic reactors. GAC samples from a 3-ethylphenol (3-ep) fed reactor were used in batch experiments with 3-ep as the substrate and GAC samples from an orthochlorophenol (OCP) fed reactor were used in batch experiments with OCP as the substrate. Data were observed to fit Haldane kinetics and predictions from the Haldane kinetic parameters were in agreement with transient behavior from the 3-ep fed reactor. This technique was useful in predicting threshold inhibitory levels for continuous treatment of inhibitory wastewaters in expanded-bed GAC reactors. The fed-batch technique light also be applied to measure substrate utilization rates of biomass attached to other adsorbable materials such as soils.
Penetration of Biocides into Biofilm
Authors: Tashiro H. , Numakura T. , Nishikawa S. , Miyaji Y.
Published: May 2018

Penetration of three kinds of biocides into biofilm formed on the surface of PVC tubes was examined. Penetration depth curves reached a plateau in 2 hours or less. Penetration depth at the steady-state was dependent on external concentrations of the biocides in the fluids. Penetration depth was limited by decomposition of the biocides by biofilm, and the decomposing abilities were maintained even in the killed bacteria.
Biological Oxidation of Ferrous Iron in High Acid Mine Drainage by Fluidized Bed Reactor
Authors: Omura T. , Umita T. , Nenov V. , Aizawa J. , Onuma M.
Published: May 2018

The biological oxidation of ferrous iron in high acid mine drainage was studied both in the batch experiment and in the fluidized bed reactor with the Amberlite IRA-938 as a support medium.

From the batch experiment, the effects of initial ferrous iron and dissolved oxygen concentrations on the specific rate of ferrous iron oxidation could be expressed by Monod type equation.

The fluidized bed reactor achieved the ferrous iron oxidation of over 90% within the flow rate region of 0.75 1/hr to 4.5 1/hr. The ferrous iron oxidation in the fluidized bed reactor was ot so much influenced by the change in the water temperature. The fluidized bed reactor should be operated under the condition that the influent pH is not more than 2.0 because of the clogging by the ferric hydroxide.

Based on the experimental results obtained, a mathematical model which describes the behaviour of ferrous iron concentration in the fluidized bed reactor was proposed. This mathematical model well predicted the effluent concentration of ferrous iron from the fluidized bed reactor at both steady and unsteady states.
Should Waste Stabilization Ponds be Designed for Perfect-Mixing or Plug-Flow?
Authors: Juanico Marcelo
Published: May 2018

The effect of the hydraulic flow pattern on the performance of Waste Stabilization Ponds is analyzed by modelling. The analysis is made on two parameters with different removal constants (Bacteria and BOD) and for the cases of steady hydraulic loading and when hydraulic loading changes on weekends. Plug-flow ponds perform much better than perfect mixed ones for removal of parameters with high removal constants such as bacteria. Plug-flow and perfect mixed ponds perform very similarly when the removal constant is low as for BOD. Changes in the hydraulic loading regime due to weekend effect do not modify the variability of outflow quality from plug-flow ponds. These changes do affect the variability of outflow quality from perfect mixed ponds only in the case of parameters with high removal constants such as bacteria. Polishing ponds Intended for bacterial removal should be designed for plug-flow. Facultative ponds intended for BOD removal may be designed for perfect mixed, partial mixed or plug-flow. Several small ponds with short residence time located In series, or the parcellation of a single big pond with widely spaced baffles, would avoid short circuiting of effluents between inlet and outlet. However, this design does not assure a plug-flow pattern, and it may lead to the formation of dead areas and the reduction of the actual residence time of effluents within the system.
Technological Development of a Wastewater Reclamation Process for Recreational Reuse: An Approach to Advanced Wastewater Treatment Featuring Reverse Osmosis Membrane
Authors: Suzuki Yoshiaki , Minami Takeshi
Published: May 2018

The purpose of this survey is to explore ways of reclaiming wastewater to produce high-quality low-cost water for recreational reuse by using a reverse osmosis membrane in advanced wastewater treatment. We examined membrane modules that were able to be used for wastewater treatment in fiscal year 1988.

The parameters used to evaluate the membrane were the permeate quantity, permeate water quality, flux decline coefficient, and recovery rate of the permeate quantity by chemical cleaning. As a result, spiral-wound polyvinyl alcohol composite membrane and hollow-fiber cellulose triacetate reverse osmosis membrane were found to be of high practical value. The permeate through these membranes was colorless, transparent, and odorless, with an appearance equivalent to city water. The rejection rate of the fecal coliform group was 100% and the COD of the permeate was 1-2 mg/l, with a chromaticity of 1 degree or less and a phosphorus content of 0.01 mg/l. Under the same pressure condition, these membranes provided three times more permeate quantity than a conventional acetyl cellulose membrane having a time-proven performance. Moreover, these membranes were sufficiently resistant to fouling that they can recover to a 100% permeate quantity by chemical cleaning when they were fouled.
Steady State Performance of Activated Carbon Contactors
Authors: Traegner U. K. , Suidan M. T.
Published: May 2018

A mathematical model for the steady state adsorption of pollutants from completely mixed activated carbon contactors is derived in this paper. In order to accurately describe these processes, a sludge age distribution is incorporated for the adsorbent. The resulting mathematical model is solvable analytically using the homogeneous surface diffusion model (HSDM) as a descriptor of intraparticle mass transfer resistance. Various examples are included in this paper to illustrate the use of this new derivation. Effects of particle size, particle size distribution of commercial carbon, surface diffusion coefficients, and solids mass flow rate, on the performance of the completely mixed adsorption system are studied in detail. Examples of multicomponent, competitive adsorption as well as an equivalent single component representation of a target component are discussed.
Sludge Incineration Process of Kyoto City – The Employment and Heat Balance of the Step Grate Stoker Furnace
Authors: Ito Tomiya
Published: May 2018

Kyoto City, an ancient city of international tourism, has been actively constructing its public sewerage system as one of the most important policies of the city. As of April, 1989, 79.6% of the urbanization promotion area of the city has been sewered. The fully completed sewerage system will be established in 1994, the 1200th anniversary of the founding of the city as the ancient Heian capital of Japan. However, the increase of the sewered ratio effects a steady increase in the influent volume of wastewater. Due to the inland location of the city, sludge produced in the wastewater treatment plants has been landfilled after incineration, but recently the securing of appropriate sites for landfill is difficult, and hence sludge treatment and disposal is an important issue for Kyoto City.

In order to minimize the ultimate disposal volume, incineration of the entire volume of sludge has been undertaken in early days of sewerage operations. This report introduces the sludge incineration system and assesses the newly adopted step grate stoker furnace.

At present, Kyoto City has 4 treatment plants in operation. The Toba Treatment Plant, which has the largest treatment capacity receives sludge cake trucked from the Fushimi Treatment Plant and excess sludge pumped through pipes from the Kisshoin Treatment Plant, and incinerates the whole amount of sludge cake generated in the plant. The sludge cake produced at the Ishida Treatment Plant is incinerated at an adjacent refuse sanitation plant together with the municipal refuse from the city. The characteristics of sludge treatment systems are given in this report.

The step grate stoker furnace system was introduced to reduce the final disposal volume and to save energy. Through comparison with the multiple-hearth furnace system the actual results of operation were verified. The volume of generated ash was decreased by more than 50%, and energy consumption was reduced by 77%, resulting in an 18% reduction of operating expenses.
Capability of On-Site Sewage Treatment System in Japan: Case Study in the Tokyo Suburb of Nagareyama City
Authors: Nakanishi Junko , Ishiwatari Mikio , Ichimura Masakazu
Published: May 2018

The capability of an on-site sewage treatment system was examined in Nagareyama, a suburb of Metropolitan Tokyo, with the multi-objective optimization method. The total cost, local expense, drinking water quality, stream water quality and speed of sewerage service were considered and the relative weight of each evaluated by interviews with 44 citizens. In the optimal sewerage plan, about half of the planning area was concluded to be suitable for onsite treatment systems. The idea presented here is expected to be useful for other countries especially for developing ones.
Pilot Plant Studies on Tannery Waste Water Treatment with the Objective to Reduce Sludge Production
Authors: Szpyrkowicz L. , Rigoni-Stern S. , Zilio Grandi F.
Published: May 2018

The objective of the work was to verify the possibility to reduce the quantity of the sludge produced during the treatment of chrome tannery waste waters. The modified Ludzack-Ettinger process for high nitrogen content waste waters was tested without a chemical-physical pretreatment, normally adopted to eliminate from the tannery waste waters the compounds potentially inhibitory for biological processes. The results obtained in a pilot plant during 4 runs differing in waste waters flow and strength and in MLSS recycling ratio demonstrate the lack of inhibition of denitrification and nitrification by a high content of sulphides and chromium. In the comparison with traditional treatment of tannery waste waters the 60% reduction of the sludge to be wasted and the improvement of a final effluent quality were achieved. The mean overall rate of COD and N removal was 0.38 mgCOD/mgMLVSSxday and 0.125 mgN/mgMLVSSxday, respectively.
Biological Treatment of Coke-Plant Wastewater for COD and NH3-N Removal
Authors: Yibo Wen , Min Zhang , Yi Qian
Published: May 2018

For removing COD and NH3-N from high-strength coke-plant wastewater, studies were conducted in a lab scale, continuous flow system, in which anaerobic, anoxic and oxic units were included. The results have shown that the effluent COD and NH3-N of A-A/O system could be less than 78 mg/L and 4.7 mg/L respectively when the influent COD and NH3-N were higher than 1200 mg/L and 240 mg/L respectively at a total HRT of 36 hrs. Moreover, the total nitrogen of wastewater was removed by 49%. It is concluded that A-A/O system is efficient for coke-plant wastewater treatment and the anaerobic process has played very important role in the system.
Cost Optimization of Sewage Sludge Filterpressing
Authors: Mininni G. , Spinosa L. , Lotito V.
Published: May 2018

Chemical conditioning and dewatering models are utilized to determine optimal conditions in order to minimize total cost (amortization, operating and disposal) of sewage sludge filtration under pressure. The results of a parametric study are discussed in this paper. The influence on filtration time and chemicals dosage of operation variables, such as feed sludge solids concentration, specific resistance to filtration, unit disposal cost and total operating time, is investigated. Total costs range from 6,000 to 20,000 Lit/hd y and show high incidence of disposal and amortization costs (55-82%). The latter is influenced to a large extent by the total operating time, in that longer machine operation allows a great reduction in equipment size to be obtained. Results put in evidence the great importance of input sludge concentration and chemical conditioning, to obtain a sludge of better filterability.