bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
Impact de la desinfection de l'effluent d'une station depuration en zone cotiere mediterraneenne - The Impact of Disinfection of the Effluent of a Wastewater Treatment Plant on the Mediterranean Coast
Authors: Comes F. , Huau M.-C. , Kloninger P. 
Published: May 2018

The removal of microorganisms from the wastewater of municipal treatment plants is more and more in demand in order to comply with the effluents standards required for the ecotoxicological protection of the receiving water, especially to levels of seaside resorts and shellfish breeding marine areas. Therefore, in these sensitive coastal areas close to seaside resorts, the study of the bacteriological pollution of the effluents has become a priority because of the inefficiency of the traditional wastewater treatment processes for microbic contamination. The bacterial concentration levels of the effluents are usually about 106 germs per 100 ml. The aim of a disinfection unit is to reduce these germ counts to under 2000 germs per 100 ml to comply with the natural receiving water bacterial levels and in particular where the quality of the water is required for sea-bathing.
Chlorination is commonly used in the disinfection of wastewater effluents, but it does present disadvantages such as the bactericide efficiency (global bacteria elimination rate and specific species resistivity rate) which is limited. The use and storage of chemical reagents is an operating constraint.
The UV disinfection seems to be valid and efficient without any risk of toxicity in the effluent. This technique which does not require reagents is simple to maintain at low and medium flows; it is easily automated and continuously monitored.
Firstly, this paper describes comparative results for the reduction rate of bacterial concentrations using the above mentioned two disinfection techniques : chlorination and UV. A full-scale chlorination unit has been installed at the wastewater treatment plant of Canet-en-Roussillon where the received pollution corresponds to 50000 population equivalents in summer. Two UV pilot-scale units have also been installed on site. The effluents are discharged into the river Têt, the plant is located a few hundred meters from the outfall into the Mediterranean Sea downstream from a great urban center and close to a famous seaside resort.
Secondly, a survey of the impact of wastewater disinfection on the coastal area is carried out following, in particular, the bacteriological state of the beaches. If the first step of this study is to determine the efficiency of the disinfection to improve the quality of the effluent and to obtain the levels required for a seaside resort, it is also essential, in a second step, to extend the investigation to evaluate the relative impact of the disinfection on the global quality of the natural coastal water.
Biological Mechanisms of H2S Formation in Sewer Pipes
Authors: Attal A. , Brigodiot M. , Camacho P. , Manem J. 
Published: May 2018

The purpose of this study is to gain a better understanding of the biological phenomena involved in the production of hydrogen sulfide in urban wastewater (UWW) systems.
It is found that the UWW itself naturally possesses the biomass needed to consume the sulfates. These heterotrophic sulfate-reducing bacteria populations, though immediately active in strict anaerobic conditions, are present only in very low concentrations in the UWW. A concentration of them was studied within the pressure pipes, in the form of deposits, and this justifies the high concentrations of sulfides measured in certain wastewater networks.
There are two reasons why the ferrous sulfate used as a treatment in any wastewater networks should not cause the production of additional sulfides. Firstly, the sulfate consumption kinetics are always too slow, relative to the residence time of the water in the pipe, for all of the sulfates to be consumed anyway. Secondly, the amount of assimilable carbon, soluble carbon, and carbon from suspended solid (SS) hydrolysis is insufficient.
High Rate Air Activated Sludge Operation at the City of Los Angeles Hyperion Wastewater Treatment Plant
Authors: Shao Y. J. , Crosse J. , Keller E. , Jenkins D. 
Published: May 2018

The City of Los Angeles USA Hyperion Treatment Plant (HTP) implemented high rate air activated sludge operations in November 1989. Using this process, the secondary treatment organic loading (F/M) was increased from 0.5 to 1.0 kg BOD/kg MLVSS/day and the MCRT reduced from 3.1 days to 1.5 days, thereby enabling the secondary treated flow to be increased from 150 mgd to 200mgd (6.6 to 8.8 m3/s).
Excellent secondary effluent quality (BOD5 = 15 mg/l, carbonaceous BOD5 = 6 mg/l, SS = 6 mg/l) is currently obtained using rectangular secondary clarifiers operated at surface overflow rates of 1,100 gal/day/ft2 (43 m3/m2/day) and low MLSS concentrations (950 mg/l). The enhanced biological phosphorus removal that was obtained when operating at a 3 day MCRT was eliminated in the change to high rate operation and struvite (MgNH4PO4(c)) build-up in the anaerobic digesters has been eliminated. Nocardia scum formation, with its odor generating potential and other associated operating problems, has also been eliminated by high rate operation.
Study of the Factors Affecting Activated Sludge Settling in Domestic Wastewater Treatment Plants
Authors: Echeverría E. , Seco A. , Ferrer J. 
Published: May 2018

A study has been made of the influence of the process parameters on the settling characteristics of sludge in domestic wastewater treatment plants. The experiments were conducted at a pilot plant situated at the Wastewater Treatment Plant of Valencia, Spain (1,000,000 inhabitants). The influent to the pilot plant was the same as that of the plant.
It was found that F/M ratios in the range of 0.25-0.60 g DBO5/g MLVSS day produce values of SVI representative of good settleability of the sludge. Values of sulphide concentration in the influent above 1.0 mg/l negatively affect the process, causing bulking and floating sludge. High values of fats were found to have no influence on the SVI, but did affect the performance of depuration. At low DO levels, the appearance of bulking with high SVI values was observed. Throughout the experiments, the permanence of nutrients (basically N and P) above that required for the growth of the microorganisms was proved.
Minimising Nuisances by Covering Compact Sewage Treatment Plants
Authors: Rogalla F. , Roudon G. , Sibony J. , Blondeau F. 
Published: May 2018

Stringent effluent quality programs to limit wastewater discharges into receiving waters require extensive upgrading of conventional wastewater treatment plants. Large facilities built some decades ago are now often located in densely urbanised areas where land is unavailable. Since nitrogen and phophorus removal often require additional unit processes, innovative solutions have to be found to upgrade existing plants for nutrient removal. This paper shows large scale examples of compact technology and the additional upgrading flexibility provided.
New facilities are implemented in sensitive neighborhoods by creative siting under sports stadiums, parks or buildings. In covered plants, air emission control becomes of primary importance. To reduce visual impacts and facilitate odour control, more and more underground treatment plants are constructed, allowing multiple use of plant surfaces. Several plants are illustrated in inner-city locations, avoiding infrastructure cost to pump sewage to remote sites.
Most of the presented plants incorporate spacesaving settling facilities and high rate biological reactors to reduce the ‘footprints' of the installations and thus favour coverage. Parallel plates in primary setllers reduce the surface to about one tenth of conventional systems. Biocarbone aerated filters combine biodegradation with very high removal rates and retention of particles in one reactor, without additional clarification or filtration. Air treatment for large plant is mostly performed by chemical scrubbing, completely eliminating environmental nuisances. Performance results of both air and water treatment technology are given.
Examples include recent sewage treatment plants on the French Mediterranean Coast. A physico-chemical treatment plant for 1 Million p.e. has operated since 1987 under a stadium in Marseille. In Monaco, the sewage treatment plant for 100 000 p.e.is located in the city center underneath a building of 3000 m2. Primary lamella settlers are followed by biological treatment on Biocarbone aerated filters and air is chemically deodourised. Similar technology is used in Antibes' 200 000 p.e. plant, integrated underneath a park close to the beach.
Heavy Metals in Wastewater Treatment Plant Sludges in the Czech Republic
Authors: Sedláček M. , Just T. 
Published: May 2018

Since 1987 operators of municipal wastewater treatment plants, having the population equivalent over 5 000, monitor systematically heavy metals in sludges, based on one or two samplings on the average annually. Generally, Cd, Cr, Cu, Ni, Pb and Zn are monitored: since 1989 Hg is becoming the centre of systematic attention. Occasional data are available on concentrated Ag, Co, As and Mo. These data were collected and ordered by the authors of the paper. On their basis lines of exceedance were plotted and sets were prepared, characterizing both localities with the common level of the sludge contamination, and with the extremely low contamination level reflecting the condition that could be achieved if measures limiting the heavy metal input into public sewerage systems were adopted.
The results achieved were compared with heavy metal concentration limits, as determined in the Industrial composts standard, both for raw materials used for the compost production, and for composts of Ist and IInd grades. With a view to the general environmental contamination, and considering the present economic and agricultural use, the input raw materials should meet the demands that are required under the standard for the prepared composts.
Improved Biological Phosphorus Removal Resulting from the Enrichment of Reactor Feed with Fermentation Products
Authors: Lötter L. H. , Pitman A. R. 
Published: May 2018

Research in South Africa has highlighted the dependence of biological phosphate removal mechanisms on the presence of certain minimum concentrations of some readily biodegradable materials including interalia volatile fatty acids. Successful generation of these compounds has been achieved at recently commissioned facilities at three of Johannesburg' activated sludge plants. Elutriation of the volatile fatty acids from the sludge was achieved by recycling sludge to the influent sewage stream. Significant improvements in phosphate removal were observed, thus reducing the demand for chemical dosing to achieve the phosphate standard.
In this paper the effect of altering the feed sewage characteristics on biological phosphorus removal is discussed.
Application of Linked Personal Computers for Automatic Control in Large Sewage Works
Authors: Bongards M. , Braun J. , Feyen H. A. 
Published: May 2018

So far only very large sewage treatment plants (STP) are equipped with real process computers. High investment costs and complicated handling prevented their application in medium-sized and smaller STPs. Meanwhile Personal Computers became so efficient and reliable that they can be used for automatic control of industrial processes.
In this paper the successful enlargement of the central STP of Stolberg-Steinfurt for 120,000 inhabitant equivalents is described. In the central facility seven linked personal computers co-operate in a local area network (LAN) for monitoring and optimization of different processes. They are connected with seven programmable controllers in outstations on site. The data transfer between the central control room and the outstations takes place using RS 232 C interfaces. Because of the use of common office computers in combination with industrially proved controllers the operators very soon accepted the system. After one year of operating experience they assess the system as a valuable tool.
Prevention of Pollution from Spills: The Human-Machine Interface Factor
Authors: Weaver L. , Lyon W. A. , Price H. E. 
Published: May 2018

Environmental incidents resulting from a spill or release of hazardous materials are often attributed to human error such as carelessness, faulty attitude and inattention. Manufacturing and related urban growth processes in the Great Lakes Basin have resulted in an estimated 3000 significant spills of toxic contaminants annually. The International Joint Commission on the Great Lakes of Canada and the U.S. (IJC) is concerned that these spills contribute significantly to the toxic burden in the Great Lakes Basin and that a catastrophic accident might permanently damage Lake ecosystems.
Spills are often caused by a breakdown in the complex relationships between humans and machines. The IJC sponsored workshops to assess concerns at the human-machine interface and develop findings and recommendations on data reporting and analysis, research, communication, training, education and institutional needs. Experts in a diversity of related fields participated.
This paper introduces the human-machine aspects of spill prevention and relates findings and recommendations of the IJC workshops which are designed to develop and encourage application of a systemic approach to the prevention of spills. This approach includes human design factors considered in the earliest stages of facilities planning and design based on application of the body of knowledge already in place and in continuing development in nuclear power and aviation industries and associated governmental programs.
Biotower Pilot Study Results for a Photographic and Specialty Paper Manufacturer
Authors: Cleary J. G. , Boehm T. J. , Geary R. J. 
Published: May 2018

Schoeller Technical Papers, Inc. (Schoeller), which manufactures photographic and other specialty papers, is located in Pulaski, New York. The wastewater treatment system consists of a primary clarifier and two settling lagoons. Secondary treatment using a biotower was proposed to meet the new New York State Pollutant Discharge Elimination System (SPDES) discharge limits for BOD and TSS. The effluent from each basin is discharged directly to the Salmon River, at an approximate average flow of 1.6 million gallons/day (mgd).
A biotower pilot study was performed to evaluate the suitability of a biotower treatment process for treating the total effluent from Schoeller's facility. The pilot study was used to select the media for the full-scale biotower and to confirm the design loading for the full-scale biotower, which proceeded in parallel with the pilot study due to the schedule constraints. Two pilot systems were operated to compare a conventional cross-flow and vertical media. Test data were collected to evaluate the performance of each pilot treatment system at a range of loading conditions and to develop the design loading information for the full-scale plant.
The pilot units were operated for a period of 10 months. BOD concentrations to the pilot units averaged 58 mg/l with a peak of 210 mg/l. Approximately 80% of the BOD was soluble. BOD loadings averaged 21 lb BOD/day/1,000 cubic feet with a peak of 77 lb BOD/day/1,000 cubic feet. Both pilot units achieved excellent BOD removals exceeding 75%, with average effluent soluble BOD concentration less than 10 mg/l and average effluent TSS concentrations of 12 mg/l. The two media achieved comparable performance throughout most of the pilot study.
Nitrification with Biofilms on Small Suspended Particles in Airlift Reactors
Authors: Tijhuis L. , van Loosdrecht M. C. M. , Heijnen J. J. 
Published: May 2018

The development of nitrifying biofilms and short and long term influences on the nitrification process were studied in a Biofilm-Airlift-Suspension-reactor. The studied changes are (i) startup of nitrification reactor at different dilution rates, (ii) the effect of temperature on N-oxidation capacity, (iii) the short term effect of N-loading rate on conversion to determine the nitrification overcapacity and (iv) long term effect of N-loading rate on conversion to determine the maximum nitrification capacity in this reactor system.
It is shown that the specific nitrification capacity during start-up is constant, 1 g N/(gorg.mat. d), which is high compared to the activated sludge process. The influence of the temperature on the nitrification rate is much less than can be expected from pure culture experiments. On a short term there is only a small nitrification overcapacity in the reactor. The maximum nitrification rate during these experiments was 6 kg N/(m3 d), which is very high compared to the activated sludge process.