bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Saving and Wastewater Reuse and Recycle in China
Authors: Zhongxiang Zhang , Yi Qian
Published: May 2018

With the development of industrial economy and urban construction, water pollution and water shortage in China have become very serious problems in recent years. In this paper, a general picture on water pollution and water shortage in China is described. The regulations of technical policy of Water pollution prevention and control of PRC are introduced. The major measures of water saving in industries and cities are presented. The reuse of reclaimed municipal wastewater as a secondary water source is recommended. Some demonstration projects of wastewater reuse for different uses are presented. Research works concerning reuse and recycling system of industrial wastewater are presented as well.
A Pilot-Plant Study to Salvage a Full-Scale Treatment Plant
Authors: Yu Y. H. , Lo K. S. L.
Published: May 2018

Kwei-Shan Wastewater Treatment Plant is the second oldest treatment plant ever designed and operated in Taiwan, to treat the combined industrial wastewater collected from various kinds of factories located in Kwei-Shan Industrial Park. From the beginning the treatment plant has been suffering from influents containing a spectrum of various pollutants harmful to the activated-sludge system of the plant. Extreme pH measurements (1.4-12.0), jumpy organic contents (COD 104-6660 mg/l), high metal concentrations (Cu up to 19 mg/l, Zn up to 37 mg/l), and high grease concentrations (up to 470 mg/l) were unbelievably found in tne plant influents, while a traditional plain primary settling tank was the only shield to protect the aeration basin from damage. In a dilemma like this, a pilot-plant study was undertaken to save the efficiency of the existing biological treatment plant from those various fatal influent constituents. A flow equalization tank and a chemical treatment unit were first built to damp out pH and COD variations, Ca(OH)2 was added to remove the toxic metals as well as part of the grease. The effluent after the above treatment was then neutralized and sent to the downscaled activated sludge system containing one aeration tank and one settling tank. The results indicated that equalization and chemical precipitation by using the existing space of the roughing filter and the sedimentation tank could produce much safer influents to the activated sludge system.
Public Evaluation of Fish Tainting from Pulp and Paper Mill Discharges
Authors: Jardine C. G.
Published: May 2018

As part of the Remedial Action Plan (RAP) programs for the St. Lawrence and Spanish Rivers in Ontario, Canada, tainting evaluations were conducted using members of the Public Advisory Committees (PACs) and the RAP teams. Triangle test sensory evaluations were conducted on caged rainbow trout (Salmo gairdneri) exposed insitu upstream and downstream of the pulp and paper mill diffuser outfalls In the St. Lawrence River only, evaluations were conducted on indigenous yellow perch (Perca flavescens) caught upstream and downstream of the mill discharge . In both locations, the odour of the flesh from the caged trout exposed above the diffuser outfall was not judged significantly different from caged trout exposed downstream of the discharge. However, the indigenous perch caught downstream of the mill in the St. Lawrence River were judged by the panelists to have a significantly more objectionable odour than those caught upstream of the discharge. While the effluent tainting potential appears to have been eliminated in the Spanish River, further studies are required to determine the source and magnitude of tainting concerns in the St. Lawrence River. The sensory test and results reported here provide useful tools for evaluating the tainting potential of pulp mill discharges and for assessing perceived consumer quality of the fish exposed to these effluents.
U.S. Regulatory Approaches: A Critical Appraisal
Authors: Williamson R. L.
Published: May 2018

The American approach to environmental regulation is characterized by fragmentation of responsibilities, primary reliance on command and control regulations, extraordinary complexity, a preference for identifiable standards, and heavy resort to litigation. This system has provided important benefits, including significant reduction of environmental contamination, substantial use of science in decision-making, broad participatory rights, and the stimulation of new treatment technologies. However, these gains have been achieved at excessive cost. Too much reliance is placed on command and control methods and especially on technology-based standards. There is too much resort to litigation, and inadequate input from science. Participatory rights are being undermined, and there is a poor allocation of decision-making among the federal agencies and the states. Over-regulation sometimes leads to under-regulation, and insufficient attention is given to the impact on small entities. The responsibility for these difficulties rests with everyone, including the federal agencies, the Congress, the general public and the courts. Changes in the regulatory system are needed. We should abandon the use of technology-based standards to control toxic substances under the Clean Water Act in favor of strong health- and environmentally based standards, coupled with taxes on toxic substances in wastewater.
Testing of the EPA Toxicity Identification Evaluation Protocol in the Textile Dye Manufacturing Industry
Authors: DiGiano F. A. , Clarkin C. , Charles M. J. , Maerker M. J. , Francisco D. E. , LaRocca C.
Published: May 2018

The case study for evaluating the EPA Toxicity Identification Evaluation protocol was a textile dye manufacturing plant that suspected chloride as the major source of toxicity. Phase I of the protocol, together with some additional experiments, was successful in showing that one-third to one-half of the toxicity was due to chloride and the rest was due to nonpolar organic compounds. From 41 to 78 organic chemicals were found in toxic fractions using the EPA Phase II test procedures; these included dyes, dye intermediates, process chemicals such as surfactants and possibly metabolic by-products of waste treatment. A major component of Surfynol, a widely used surfactant, was present in concentrations much higher than any other chemical in the toxic fractions of all three samples analyzed. However, the concentration was still considerably less than the LC50 (mg/L) and thus could not explain whole effluent toxicity. Instead, more than one organic chemical may be involved.
Petroleum Effluent Toxicity Reduction – From Pilot to Full-Scale Plant
Authors: Wong J. , Maroney P. , Diepolder P. , Chiang K. , Benedict A.
Published: May 2018

A petroleum refining complex was required to upgrade its wastewater treatment system to meet newly adopted toxicity requirements and to handle increased flows. A four-phase investigation led to the design and construction of a full-scale PACT® system. The first phase, waste stream characterization, indicated that the effluent toxicity was organic in nature. The second phase, bench-scale screening, indicated that the toxicity was removable by activated carbon adsorption. The third phase, comparative pilot testing, indicated that although both extended aeration and PACT® processes were effective in reducing COD concentrations, only PACT® could remove the toxicity. In the fourth phase investigation, the PACT® pilot plant was tested for various conditions, including dry- and wet-weather flow conditions. The full-scale PACT® plant has been operating for more than two years and is meeting all expectations.
Use of Indigenous and Adapted Microbial Assemblages in the Removal of Organic Chemicals from Soils and Sediments
Authors: Catallo W. J. , Portier R. J.
Published: May 2018

Among the consequences of discharging industrial wastes to land and water bodies is the widespread accumulation of toxic chemical mixtures in surface and subsurface environments. It is believed that the distribution of toxic materials in the environment constitutes a threat to ecological and human health. Bioremediation of contaminated soils and sediments using indigenous and adapted microbial consortia offers the possibility of rapid and cost-effective removal of organic and organometallic compounds to low levels and nontoxic products. The purpose of this communication is to discuss the theory and practice of bioremediation as it applies to contaminated sediments, and present data on the removal and detoxification of refinery wastes containing polycyclic aromatic hydrocarbons.
Management of Toxics for the Fukashiba Industrial Wastewater Treatment Plant of the Kashima Petrochemical Complex
Authors: Kozawa T. , Wueki T. , Kobayashi H. , Matsui S.
Published: May 2018

The Kashima petrochemical complex and its Fukashiba industrial wastewater treatment plant are described. When the factories of the complex discharge the wastewater, they must be in compliance with the standards designated in the Sewage Law of Japan, because they are users of the public sewage system. Ten of 81 factories discharged the wastewater containing identified toxics, and they treated corresponding toxic items before discharging to sewers. The wastewater of the factories was constantly monitored by the office of Kashima sewage works, and there had been few troubles with the operation of Fukashiba treatment plant. However, sludge contained cadmium at relatively high concentration in Fukashiba treatment plant, compared with sludge of the domestic sewage treatment plants. The sources of Cd were possibly the use of large amount of slaked lime in these factories. Prior to the construction of any new manufacturing plant, the office of Kashima sewage works practiced the test of biodegradability and toxicity of potential wastewater from the plant. The analytical method of GC/MS became a useful tool to confirm biodegradability and toxicity of substances in the wastewater from each plant.
Processes and Modelling 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 modelling the kinetics of activated sludge systems: Completely aerobic nitrification, anoxic/aerobic nitrification denitrification (ND), and anaerobic/anoxic/aerobic nitrification denitrification biological excess phosphorus removal (NDBEPR) systems. The paper highlights the progress in developing a general NDBEPR activated sludge kinetic model – development of polyP organism enhanced cultures, their kinetics, simplification of the kinetics for enhanced cultures under constant flow and load conditions, extension of the simplified model to mixed culture NDBEPR systems under constant flow and load conditions, integration of the polyP organism enhanced culture kinetics with the ND kinetics to give a general NDBEPR kinetic model for cyclic flow and load which incorporates the increased specific denitrification rates observed in NDBEPR systems compared to ND systems. Areas of research that require attention to complete the development of the general NDBEPR kinetic model are identified – denitrification by polyP organisms, calibration and verification of the model for cyclic flow and load, etc.
Designing Experiments to Determine the Coefficients of Activated Sludge Models by Identification Algorithms
Authors: Larrea L. , García-Heras J. L. , Ayesa E. , Florez J.
Published: May 2018

A calibration technique comprised of an experimental procedure and a curve fitting mathematical method has been proposed in order to estimate the coefficients of the IAWPRC activated sludge model restricted to oxic reactions. A continuous activated sludge plant having two in-series biodegradation reactors is suggested for the experiment. This plant is operated by reducing, in steps, the first reactor volume. It was found that this experimental procedure enables scanning of a significant part of the kinetics contained in the model. The curve fitting mathematical method was an identification algorithm based on recursive non-linear Kaiman filter. In order to assess the validity of the calibration technique, simulated results of measurable variables, generated from presumed real coefficients, have been employed as real results by the identification algorithm. The effect of several erroneous initial estimates of the coefficients, which are required to start the identification, has been investigated. It was found that the proposed calibration technique gave rise to acceptable identifications of the real coefficients independent of the initial estimate used. The convergence rate for every coefficient, however, depends on the initial estimate. Those rates were properly related to the differences observed between the real results and the predictions obtained with the initial estimates for the measurable variables.
Towards a Comprehensive Model of Activated Sludge Bulking and Foaming
Authors: Jenkins David
Published: May 2018

The physiological properties of filamentous and floc-forming microorganisms found in activated sludge are reviewed. From this review four model microorganisms - two floc formers and two filamentous organisms - are proposed for use in an activated sludge model that predicts activated sludge “quality”.
A Dynamic Secondary Clarifier Model including Processes of Sludge Thickening
Authors: Härtel L. , Pöpel H. J.
Published: May 2018

Dynamic simulation models of the activated sludge process are a planning and designing tool solving and answering problems that cannot be dealt with by static design models or procedures. In dynamic modelling, however, the settling and thickening processes have to be taken into account which have been neglected until now.

Therefore, a dynamic model simulating the processes of settling and of thickening in the secondary clarifier is developed and finally integrated into a dynamic biochemical reaction model. The validity of the model approach is evaluated by simulation runs showing the velocities of hindered settling, the concentration profiles of MLSS over the tank depth, and the effluent concentrations of MLSS. Basic variables for the validation are the influent MLSS concentrations and the sludge volume index quantifying the settling characteristics of the sludge.

The consequences for the MLSS content in the aeration tank, as well as for the plant effluent quality, of neglecting and of including the clarifier model into the integrated model are shown at variable conditions of wastewater inflow, especially for periods of higher storm water flows to the treatment plant
Modelling of the Secondary Clarifier Combined with the Activated Sludge Model No. 1
Authors: Dupont René , Henze Mogens
Published: May 2018

Modelling of activated sludge wastewater treatment plants is today generally based on the Activated Sludge Model No. 1 combined with a very simple model for the secondary settler. This paper describes the development of a model for the secondary clarifier based on the general flux theory for zone settling, which can be used in combination with the Activated Sludge Model to form a dynamic computer model/program for a wastewater treatment plant. In addition to the flux model, the developed model includes a simple model for predicting the contents of paniculate components in the effluent This latter model is a purely empirical model, which connects the effluent quality with the hydraulic load, suspended solids load and the nitrate load.

The paper describes the model and gives some basic examples on computer simulations and verification of the model.
A Structured Model of the Anaerobic Granule Consortium
Authors: Guiot S. R. , Pauss A. , Costerton J. W.
Published: May 2018

This paper presents a synthetic review of studies conducted recently and consolidated by other literature insights that substantiate a multilayer structured model of the population organization in the anaerobic granule. Syntrophic bacteria associations would be located between an external, predominantly acidogenic, layer including also H2-consuming bacteria, and an aceticlastic core. This was evidenced conjointly by electron microscopic observations of cross-cleaved granules, by the specific activity analysis of stepwise abraded granules and by the changes in the specific metabolic activities with granule size distribution and enlargement. Such a structure was deduced from observations of propionate degradation in spite of endergonic conditions in the bulk liquid, of the two-step transfer of CH4 and H2 from liquid to the gas bubbles and from a substrate and product diffusion model which differentiates active zones for trophic groups along the granule radius. Such a structured aggregate is a stable metabolic arrangement that creates optimal nutritional conditions for all its members.
The Effect of the Liquid Upflow Velocity and the Substrate Concentration on the Start-Up and Steady-State Periods of Lab-Scale UASB Reactors
Authors: Campos C. M. M. , Anderson G. K.
Published: May 2018

This research was carried out in order to study the effect of the upflow liquid velocity (ULV), the COD concentration, the volumetric loading rate (VLR) and the hydraulic loading rate (HLR) on the start-up and steady-state performance of UASB reactors treating soluble substrate with 3,000 mgCOD/l at mesophyllic temperature (35°C).

Three lab-reactors (UASB) were constructed with different liquid volumes, and also with different cross-sectional areas. The three UASB reactors were started up with the same biological loading rate (BLR), but the start-up procedures were based on different criteria.

After the start-up had been carried out successfully with the formation of the granules, all the three UASB reactors were operated under steady-state conditions for up to eight different HRT(s), namely: 16, 14, 12, 10, 8, 6, 4 and 2 hours.

For each of the three reactors the kinetic parameters were determined using the Monod model. Analysis of the influence of the operational factors and reactor design on the kinetic coefficients is described. The results indicate that the liquid upflow velocity has considerable effect on the sludge in this type of system, thereby acting as a selective process in the cultivation of the biomass.

Analysis of sensitivity on the kinetic parameters indicated which was the most sensitive kinetic parameter for these reactors.
Field Test of a Composite Methane Gas Production System Incorporating a Membrane Module for Municipal Sewage
Authors: Kiriyama K. , Tanaka Y. , Mori I.
Published: May 2018

We examined a field test plant based on anaerobic sewage treatment to elucidate the process of methane fermentation with a UASB in municipal sewage and domestic waste water.

The process consists of a pretreatment system for sparating suspended solids, a hydrolyzation reactor with a membrane module for organic solids, and a UASB reactor. The membrane module increases the sludge residence time in the hydrolyzation reactor. This field test plant is a commercial size system which combines these processes to verify the feasibility of the system.

The aim of this practical test is to produce gas with a conversion rate of over 60% when the volumetric organic loading rate is more than 2 kg BOD/reactor m3.d, and to construct a methane gas generation system which generates the gas from raw sewage. This practical test demonstrated gas conversion rates from 57% to 60.0%. Volumetric organic loading rate was 1.4 - 2.0 kg BOD/m3.d; BOD removal was 70 - 80% at ambient temperature, and excess sludge did not exceed 0.04 kg per sewage.m3.
Anaerobic Removal of Chlorate from Bleach Effluents
Authors: Malmqvist Å , Welander T.
Published: May 2018

Anaerobic biological removal of chlorate was studied on a laboratory and pilot plant scale. Continuous laboratory tests in an anaerobic fixed-film process showed that chlorate can be removed completely from kraft bleach effluent at such a short hydraulic retention time as 0.6 h. The efficiency of biological chlorate removal was confirmed under practical conditions in a 20 m3 pilot plant, operating at a Swedish craft mill.

Four chlorate reducing bacterial strains were isolated and characterized. All four isolates were gram-negative, catalase- and oxidase-positive, motile rods. None of the four isolates could ferment glucose, while they could all grow aerobically and with nitrate as electron acceptor.
Evaluation of Urban Runoff Volume to Be Treated at the Outlet of Separately Sewered Catchments
Authors: Saget A. , Chebbo G. , Bachoc A.
Published: May 2018

The purpose of this study was to estimate the volume of urban stormwater which must be treated in order to achieve a given efficiency in terms of pollutant retention in a storm basin. The data used for this were those from the French national programme (1980-82), collected in four separately sewered catchments whose area is less than 100 hectares. The intercepted loads for one year and for the most polluted events have been calculated for interception volumes varying between 0 and 300 m3 per impervious hectare. It was concluded that 100 m3/imp ha can intercept about 80% of the annual load of SS, BOD5 and COD. But for the most polluted events, to achieve the same efficiency (80% of the produced load), a reservoir volume of 200 m3/imp ha is needed. The reduction of frequency of the most polluted events was also studied: for the events of which the load is in excess of 5% of the annual load produced, even a storage volume of 200 m3/imp ha is insufficient to entirely prevent these occurring.
Compliance Testing for Ocean Outfall Performance Utilising Natural Fluorescence of Effluent in Seawater Mixtures
Authors: Kaye R. B. , Haddad P. R.
Published: May 2018

Water samples were collected from public beaches at Sydney, Australia. The beaches were situated at various distances from the three major shoreline ocean outfalls discharging primary effluent. The samples were tested for faecal conform and faecal streptococci indicator bacteria. The same samples were also analysed for natural fluorescence. Excitation wavelength used was 280 nm and fluorescence emission from seawater effluent mixtures was observed at 445 nm. Indicator bacteria densities correlated well with fluorescence intensities for beach monitoring stations north of Sydney Harbour. Best correlations were observed for the stations situated within 5 kilometres from the outfall. Indicator bacteria densities were not as well correlated with fluorescence intensities for the stations south of Sydney Harbour. However, similar emission spectra were observed for all samples collected from stations both north and south of Sydney Harbour. Nevertheless, indicator bacteria densities for southern stations were observed to be better correlated with fluorescence intensities on particular days. The stations north of Sydney Harbour are believed to be impacted only by the one outfall at North Head. However the system south of Sydney Harbour is more complex. The southern stations are known to be impacted by any, or all of the three major outfalls at Bondi, Malabar, and North Head. Fluorescence can be used to determine effluent concentration in ocean waters where the origin of the effluent is known. There should also be opportunities for the development of fluorescence as an alternative indicator for “real time” public health monitoring of recreational waters.
Environmental Impact Evaluation of Istanbul Wastewater Treatment and Marine Disposal Systems
Authors: Ozturk I. , Zambal T. , Samsunlu A. , Göknel E.
Published: May 2018

Metropolitan Istanbul Wastewater Treatment System contains 14 marine outfalls, seven of which include secondary stage biological treatment processes. The others have only mechanical treatment units including bar screens and grit chambers. Only one mechanical pre-treatment and marine disposal system, Yenikapi plant, has been operated since 1988 among these 14 plants and six of them are ready for construction. In this paper, the environmental impact of Yenikapi pretreatment and marine disposal system on the water quality of the Bosphorus and the Sea of Marmara has been investigated. Long term water quality measurements which were performed in pre-and post-dischange applications have been evaluated. Water quality parameters including pH, DO, BODs, TKN, P and total coliforms were measured at various sampling stations around the discharge points. A general evaluation of marine outfall systems to be constructed in the scope of Istanbul wastewater treatment project, on the water quality of the Sea of Marmara and the Bosphorus has been presented.
Modeling of Ocean Outfall Discharges
Authors: Roberts P. J. W. , Williams N.
Published: May 2018

Bacterial modeling techniques for the San Francisco ocean outfall are reviewed. Extensive oceanographic measurements, and field and laboratory experiments were done. The oceanographic data are briefly reviewed and it is shown that all parameters are subject to considerable spatial and temporal variability. A “wandering puff” model is used to compute the frequency distribution of shoreline bacteria. The model accounts for varying initial dilution due to variation in stratification, current speed and direction, and effluent flowrate, far field diffusion due to oceanic turbulence, spatial and temporal variation in current speed and direction, and diurnal variation in bacterial decay rates. It is predicted that bacterial concentration standards will be met at all shoreline locations without effluent chlorination. Areas of uncertainties in our present knowledge of mixing processes are briefly reviewed, and likely future trends discussed.
Topics of Environmental Education Program in Coastal Areas
Authors: Rennhack A. M. O. , Zee D. M. W. , Cunha E. S. , Portilho M. F.
Published: May 2018

Researches and Studies made by the Department of Oceanography of the Institute of Geoscience of the State University of Rio de Janeiro UERJ, evidenced the need for educational support where environment-related questions were concerned.

A wide range of environment problems tend to concentrate in coastal areas, owing to disordinate urban growth combined with the lack of substructure to cope with it A large number of these problems can be minimized through the participation of the local community. Thus the goals of environmental education are to supply information, to promote a change in the population's attitude toward environmental problems, besides stimulating its participation by fostering its sense of responsibility.

Preliminary results have demonstrated that the community has shown great interest in the work that has been proposed, and it has contributed with participation, promising response.

Environmental education is fundamental when we consider possible solutions for environmental problems in coastal urban centers. Only by educating the main cause of environmental problems, man himself, will it be possible to consider the question starting from its very origin. This abstract presents two pioneer experiments in the Municipio of Rio de Janeiro, which are “Muito Prazer Marapendi” (“Glad to know you, Marapendi”) and “Troca de Areias da Praia de Copacabana” (“Exchange of Sands in Copacabana Beach”).
An Example of How Bad Public Relations Can Defeat a Good Water Pollution Control Project
Authors: de Britto E. R. , Almeida S. A. S. , Gonçalves F. B.
Published: May 2018

Cedae, a Rio de Janeiro Government Agency, carefully planned and designed an ocean outfall to be built in Barra da Tijuca, one of the most valuable and beautiful dwelling regions of Rio de Janeiro.

Due to the non-implementation of a public enlightening campaign, Cedae had to face radical community opposition to the outfall construction, fronted by very active persons, interested in personal promotion in a political elective period.

The authors concluded that it is indispensable for any planned public work to put an action in enlightening public information program, based on fact and mutual understanding, to inform the community to be served about the various technical, economical and social questions involved and as to the facilities to be built.
Dewatering Sludges Using a Novel Membrane Technology
Authors: Rencken G. E. , Buckley C. A.
Published: May 2018

A novel tubular configured filter press has been developed for the filtration or dewatering of sludges. The unique features of this filter press are:during the cake deposition stage, sludge is fed under pressure into a self-supporting array of horizontal collapsible porous fabric tubes (the cake is deposited on the internal walls of the tubes).during the cake removal stage, sludge is pumped through the array of tubes at a high velocity and the cake is dislodged from the tube walls by means of a roller cleaning device which traverses the length of the array of porous tubes. The dislodged cake, which is in the form of flakes, is simultaneously hydraulically transported out of the tubes, drained and conveyed to a collection hopper.

A brief process description of the tubular filter press process is given. A prototype unit was erected at a water treatment plant to dewater clarifier waste sludge. The cake produced by the filtration of the clarifier waste sludge was very compressible. After tube blockage problems were experienced during the filtration cycle on the prototype unit, research was done on the deposition of a compressible cake inside a porous tube. A predictive internal cylindrical compressible cake filtration model was developed. The results of this research work are discussed. The differences between internal cylindrical, external cylindrical and planar compressible cake filtration are highlighted.

At various times low cake recoveries (high cake losses) were experienced on the prototype unit. An investigation was consequently conducted into the dislodging of a very compressible cake during the cake removal process. The results of this investigation are discussed.
Evaluation of Reverse Osmosis for Electroplating Effluent Treatment
Authors: Schoeman J. J. , van Staden J. F. , Saayman H. M. , Vorster W. A.
Published: May 2018

A South African developed tubular cellulose acetate reverse osmosis (RO) system from Membratek (Pty) Ltd was evaluated for the treatment of nickel rinse water and mixed electroplating effluent. Spiral wrap polyamide (DuPont) and thin film composite (FilmTec) membranes were evaluated for cadmium and chromium rinse water treatment, respectively. Preliminary laboratory results have shown that nickel rinse water should be treated economically with tubular RO. Approximately 92% of the rinse water could be recovered for reuse. The RO brine is of suitable quality for reuse in the electroplating process. Plant payback for a 5 m3/h nickel/water recovery RO plant was determined to.be 1.3 years (approximately 2 000 mg/ℓ Ni in feed). No severe membrane fouling was encountered during the investigation. However, membrane fouling can affect the process adversely and this will be studied further.

Approximately 90% water, of suitable quality for reuse as rinse water in the plating process, could be recovered from mixed electroplating effluent. Effluent volume for subsequent treatment with lime was significantly reduced.

It may also be possible to treat cadmium and chromium rinse waters with RO. Approximately 92% and 91% water, of suitable quality for reuse as rinse water, could be recovered with spiral wrap polyamide and thin film composite membranes, respectively. Membrane fouling was experienced during cadmium rinse water treatment. However, water flux could be restored by chemical cleaning. Very little fouling was experienced during chromium rinse water treatment. The fouling potential of the rinse waters for the membranes and subsequent cleaning procedures will be studied further. Preliminary results have shown that payback for 5 m3/h RO cadmium/water and RO chromium/water recovery plants should be 3 and 7 years, respectively.

Reverse osmosis has been shown to be a very effective technology for water and chemical recovery and for effluent volume reduction. The electroplating industry causes serious pollution and wastes large volumes of water. Consequently, RO is a technology that may be applied to good effect in the electroplating industry to control pollution and to save scarce water.
Optimal Design Applied to Ultrafiltration on Tertiary Effluent with Plate and Frame Modules
Authors: Vial D. , Phan Tan Luu R. , Huyard A.
Published: May 2018

Ultrafiltration trials were performed on a secondary clarifier effluent from a municipal waste water treatment plant. A Methodology for Experimental Research has been applied to optimize the ultrafiltration process. The results wereusedto scale-up a full plant producing 480 m3/d.
Electrodialysis Reversal at Tutuka Power Station, RSA-Seven Years' Design and Operating Experience
Authors: Hughes M. , Raubenheimer A. E. , Viljoen A. J.
Published: May 2018

The operating and design experience gained during the past seven years of the Electrodialysis Reversal Plant at Tutuka Power Station was evaluated. Factors like plant design and performance measures such as water recovery, salt rejection, current efficiency and CaSO4 saturation were investigated. The valuable operating experience has led to several design improvements to the EDR units, the clean in place system and the feed water pretreatment. Water recovery of 75%, salt rejection of 65% and current efficiency of 86% were achieved. Water recovery and salt rejection can be improved upon as very low CaSO4 saturation analyses were recorded. Plant availability varied between 90% and 57% but is expected to return to 90% as throughput increases. Membrane life has proven to be in excess of guarantee figures. Total production cost of R361,82/M1 was achieved. In conclusion the plant has successfully achieved its aims during the past seven years.
The Use of Computer Simulation of Tubular Reverse Osmosis in Conjunction with Pilot-Plant Studies
Authors: Brouckaert C. J. , Buckley C. A.
Published: May 2018

A computer model, based on the equations formulated by Sourirajan and Matsuura (1985), has been used to analyse data generated by a tubular reverse osmosis (TRO) pilot-plant treating a cooling-tower blow-down stream at Lethabo power station near Sasolburg, South Africa. These data, covering more than 3 000 hours of operation over a period of 10 months, were examined in terms of the variation of modelling parameters, as determined by regression, with time. This transformation of the data has yielded valuable insight into the effect of the plant's operating history on the condition of the membranes. Furthermore, using the model to simulate the operation of a full-scale plant has made it possible to explore some of the implications that the pilot-plant measurements hold for an eventual design.

Simulation is not yet able to substitute for pilot-plant investigation, particularly in cases of complex and/or fouling streams such as are often encountered in industrial effluent treatment applications, but may be used.very effectively to enhance the quality of information gained from such studies.
The Feasibility of Tubular Reverse Osmosis for Water Reclamation on a Large Scale
Authors: Slim J. A. , Devey D. G. , Vail J. W.
Published: May 2018

The City of Port Elizabeth designed its main sewage treatment works with water reclamation in mind and, as the reverse osmosis process, in earlier pilot plant investigations, had shown promise in its ability to produce potable water from a sewage works tertiary effluent, a full scale tubular reverse osmosis (RO) plant was installed and operated for about 12 000 hours.

The investigation showed that, although renovated water of high quality can consistently be produced under normal sewage treatment plant operating conditions, using existing plant operating personnel, frequent mechanical and instrument failures indicated the need for more reliable equipment. Feed flow to the plant averaged 25 475 1/hr with a product recovery rate of 67.5%. A 13% reduction in peak standard flux occurred, indicating that membrane fouling could be controlled within acceptable limits even though the feed received no pre-treatment other than rapid sand filtration and chlorination. No abnormal degradation of the membrane was indicated.

The results obtained indicated that chemically the product was of good potable quality with the possible exception of the levels of ammoniacal nitrogen, phenols and organic pollution indicators. Bacteriological quality of the product was not satisfactory but this could easily be rectified by the provision of adequate post disinfection. Daphnia pulex toxicity tests indicated that the RO product was on occasion undesirable for human consumption.

The total cost of the RO product was R l.86/kl.

Although the tubular RO process has great potential for producing potable water from a tertiary sewage effluent without pre-treatment, a further stage of post-treatment is probably necessary to remove micro-pollutants.
Design and Application of a Low-Molecular-Mass Cut-Off Poly (Ether Sulphone) Membrane
Authors: Jacobs E. P. , Strohwald N. K. H. , Koen D. , Sanderson R. D.
Published: May 2018

Low-molecular-mass cut-off tubular ultrafiltration membranes have been developed at the Institute for Polymer Science at the University of Stellenbosch; the compositions and the manufacturing methods are such that these membranes can be made commercially on an industrial scale. Three membranes were designed which gave performances comparable to those of other commercial membranes.

The development work comprised detailed studies of the mechanisms of the phase-inversion process, of the solvents and non-solvents used in the gelation step, and of the factors influencing the actual physical production of the membranes.

The technology of producing the membranes was successfully transferred to the commercial-scale operation and the membranes have been shown to be economically productive and to show promise in removing colour contamination from natural surface waters and from process streams in the sugar industry.
Geometrical Models for Porous Membrane Morphologies
Authors: du Plessis J. P.
Published: May 2018

The dual goal of the analysis is the development of a microstructural geometric and micro-flow model for the investigation of membrane characteristics as well as for use in numerical simulation of macro-flow phenomena in membrane technology- Membrane structures suggest a composition of different porous regimes of vastly different microstructures and some basic types of porous media are therefore discussed, emphasizing their different influences on a traversing fluid. Incorporation of the different models into a general momentum transport equation, fit for numerical computation of membrane systems, is discussed.
Pesticide Runoff from Paddy Field and Its Impact on Receiving Water
Authors: Li S. , Migita J.
Published: May 2018

A mathematical model is developed to predict the runoff of pesticides from paddy field to a river. The model describes the long term runoff as a function of physical-chemical properties of pesticides, cultural practices and climatic conditions. It is assumed that the adsorption and desorption of pesticides between soil and water phases are in equilibrium state, while the degradation in water and soil and the evaporation from water to atmosphere are of first-order reaction. The model is used to examine the relationships between the seasonal amounts of pesticide runoff and their environmental dynamic factors. A four-stage evaluation system is proposed to assess the impact of the runoff on drinking water by taking into account the amount of application, runoff ratio, toxicity and the possibility of being removed from raw water by water purification processes. The model simulates the daily variation of contaminant level in river water, thereby providing a basis for making recommendations for pesticide usage and water management for rice cultivation.
The Pollution of Minamata Bay by Mercury
Authors: Fujiki M. , Tajima S.
Published: May 2018

Minamata Disease, methylmercury poisoning, was recognized late in 1953 among the inhabitants living around Minamata Bay. In a chemical factory situated near Minamata Bay, acetaldehyde had been synthesized by the hydration of acetylene till 1968; in the reaction mercury oxide dissolved in sulfuric acid had been used as a catalyst. Inorganic mercury in waste water from the acetaldehyde plant had been discharged into the bay and it had accumulated into bottom sediment. It was proved that a part of inorganic mercury used as the catalyst had changed into methylmercury by a sidereaction in the plant and waste water containing methylmercury from the plant had discharged into the bay and methylmercury had accumulated into the fishes. The mercury concentrations in the muds were very high: in 1963, 29~713 ppm (dry weight); in 1969, 19~908 ppm (dry weight); in 1970, 8~253 ppm (dry weight) and in 1971, 14~586 ppm (dry weight). Since 1977, dredging work had been carried out to remove mercury-contaminated mud and all of the work had finished at March 1990. The concentration of mercury in fishes from the bay was very high in 1959: shellfishes 108~178 ppm (dry weight) and fish 15 ppm (wet weight). Mercury concentration in fishes has decreased markedly since 1966. Total mercury concentration in fishes (87 species) were 0.01~1.74 ppm (wet weight) and fishes containing over 0.4 ppm of total mercury were 16 species in 1989. The hair of patients contained a high concentration of mercury, the highest being 705 ppm. In 1968, the average mercury concentration in patients was 10.6 ppm, for fishermen, the average was 9.2 ppm, and for general inhabitants, the average was 8.1 ppm. In 1982, the average methylmercury concentration in fishermen was 6.15 ppm and for general inhabitants, the averge was 3.78 ppm. Thus, the mercury content in hair decreased gradually with time. After treatment of mercury in waste water was initiated, the mercury content in fishes from Minamta Bay was gradually reduced. It is necessary to supervise strictly to avoid mercury pollution of the environment.
Aquatic Environment and Variation in Water Quality at Tatu Estuary
Authors: Chen C.-Y. , Hwang I.-J.
Published: May 2018

Tatu Estuary is an ecological area where economical, cultural, leisure and academic research potentials are enormous. Recent researches indicated that the water quality of the upper streams remained at safety conditions. However, the water body of the downstream sections starting from the outfall of the Taiwan Chemical Fabric Company (TCFC) effluent has been seriously polluted. Due to the effect of tidal flow in this area of the river, it has been very difficult for the accumulated pollutants to dispel and the situation has reached a severe level. This study proposed that legislation should be established in order to reduce and to control the industrial wastes entering the river. To cope with the effort in environmental conservation, it is hoped that water resources of Tatu Chi (River) can be used more effectively.
Assessment of Rapid Method for Determining Heavy Metals Concentration in Industrial Wastewater
Authors: Chiang P. C. , Chang E. E.
Published: May 2018

The objective of this research work is to evaluate the applicability of selecting the rapid method to replace the conventional standard method for determining heavy metals concentration in the real samples which were obtained from the textile, electroplating, leather, and food processing industries. Statistical techniques including paired t-test, factor analysis and regression analysis were introduced to compare the analytical results from the above two methods. A comprehensive evaluation of these two methods based on the principle, accuracy, precision, linear range, interference, detection limit, ease of operation, and cost analyses is given.
Determination of Ultra-Trace Levels of Elements in Water by High Resolution ICP-MS with an Ultrasonic Nebulizer
Authors: Yamasaki S. , Tsumura A.
Published: May 2018

A specially designed high resolution ICP-MS was combined with an ultrasonic nebulizer to analyze trace amounts of various inorganic contaminants contained in water samples. It was confirmed that the detection limits of most elements obtained by the proposed method were well under 1 ppt. The Standard Reference Material 1643b (trace elements in water) provided by NIST (National Institute of Standards and Technology, formerly U. S. National Bureau of Standards) was also analyzed. Concentration values obtained by this work were in good agreement with certified values for all the elements examined except for Cu. It can be concluded from the foregoing that the combination of the above two instruments materializes an extraordinarily sensitive method and paves the way for direct determination of a considerable number of trace and ultra-trace elements in water samples with acceptable speed and accuracy.
Detection of Activity-Induced Chromosomal Aberrations Using Image Analysis
Authors: Ito S. , Sumitomo H. , Matsuoka Y.
Published: May 2018

Image analysis was applied to chromosomal aberration tests carried out on Chinese hamster lung cell (CHL). First, chromosomes on pictures which had been judged to be normals or aberrations by experts were analyzed by the authors' image analyzer. 802 chromosomes including 83 aberrations were distinguished by an algorithm which was developed with shape parameters. Consequently, 91.1% of exchanged-type aberrations, 47.4% of broken-type aberrations, and 97.9% of normals were correctly distinguished. And it was concluded that this algorithm could be put into practical detections of exchanged-type aberrations. Subsequently, activity-induced chromosomal aberrations of chlorinated lake water were investigated with the developed algorithm. Activity-induced chromosomal aberrations of chlorinated water depended on the chlorination pH, revealing a pattern of decreasing activity with increasing pH. It was a converse pattern for that of chloroform production.
Behavior of Organophosphoric Acid Triesters in Japanese Riverine and Coastal Environment
Authors: Fukushima M. , Kawai S. , Yamaguchi Y.
Published: May 2018

The long-term monitoring of organophosphoric acid triesters started in 1976 in the Yodo River basin; Lake Biwa, Yodo River and the rivers in Osaka City. An extensive survey was also conducted in the Yamato River and Osaka Bay, Japan. This report presents the current levels and distributions of OPEs as well as the historical trend of TDCPP. Some or all of OPEs studied here have been detected in the entire water samples over the monitoring period. It was clear that OPEs were ubiquitous pollutants in the river and coastal waters. Total OPE levels ranged from 0.4 to 2.4 µgl−1 in the Yodo River basin, 2.4 to 12 µgl−1 in the rivers in Osaka City, 18 to 28 µgl−1 in the Yamato River basin and 0.1 to 1.3 µgl−1 in Osaka Bay. An apparent difference was found in the individual OPE level among the different water areas surveyed. In the Lake Biwa and the Yodo River, the predominant compound was TBXP followed by TCEP and TDCPP. The higher levels were observed for TBXP, TEP, TCPP and TCEP in the rivers in Osaka City. The highest TCPP level, which occupied more than 70% of OPEs' composition, was observed and the mean level reached to 13.1µgl−1 in the Yamato River. In Osaka Bay, 6 kinds of OPEs, except for TPP, TEHP and TCP, were found and the most prevalent compounds were TCEP and TBP. TDCPP had gradually increased in concentration in the Yodo River basin until 1987 from 1976 year by year. However, the reverse trend of TDCPP has been noticed during the last several years.