bluuebunny/crossref_metadata_2025_split huggingface dataset:
Public Attitude towards Water and Water Reuse
Authors: Ahmad Shamim 
Published: May 2018

This study presents the results of a survey regarding public perception and attitude towards water and water reuse in Doha located in the arabian gulf. The water supply is very generous but is corrosive due to which it often acquires a red colour. Invariably home filters are used in the kitchen and washer to get rid of the colour and taste in water. People are aware of the high cost of water production and supply in such an arid region but they did not respond positively towards sharing the cost of improvement in the water supply in spite of the fact that they pay very little for receiving more than adequate water supply.
The community in general is not well informed about the water conservation measures and the water reuse. People seemed to be prejudiced against water reuse. A large percentage of respondents did not favour water reuse in lawns and gardens, car washing, toilet flushing, industries and farming.
There is a need for better channel of communication between the water departments and the community for implementing water conservation measures and expanding the water use by organizing “water weeks” regularly, which should include exhibitions, lectures, film shows, distribution of relevant literature and poster displays, emphasizing the methods of conservation to be used and the action taken by the department in this regard, the treated water quality and the water reuse practices in Doha and elsewhere. For the present water reuse should be limited to landscaping along the roads and irrigation of farms for growing animal fodder.
Reuse of Treated Wastewater in an Artificial Stream (‘Seseragf') in Kawasaki City, Japan
Authors: Kuribayashi S. 
Published: May 2018

Kawasaki City intends to reuse treated wastewater from a sewage treatment plant as the water source for an artificial stream (called a ‘seseragi') in the Kawasaki Aqua-promenade which is to be constructed on the riverbed of the dried-up River Egawa. This paper describes the results of a study on the acceptability as the stream source of four types of treated wastewater. Short streams built in the Kase Sewage Treatment Center were used for the experiments.
Stream water quality requirements include factors affecting appearance, public health, and existence of aquatic life. In other words, growth of attached algae should be inhibited, pathogenic organisms should be at an acceptable level (as indicated by number of coliform bacteria), and the stream should be a suitable habitat for fish. In this paper, the acceptability of the treated wastewater is discussed from these three points of view.
Four types of treated wastewater were investigated, i.e., effluents from a conventional activated sludge process, a biological phosphate removal process, a biological phosphate removal process with post chlorination (addition of sodium hypochlorite), and a biological phosphate removal process with post ozonation.
It was concluded that treated wastewater from the biological phosphate removal process with post ozonation was the most suitable as the water source of the artificial stream (‘seseragi'), when the three requirements mentioned above were considered in conjunction with the influence of the disinfection method on the aquatic environment.
Incorporation of Oil Base Mud Cuttings from Drilling Wells within the Manufacture of Clay Bricks
Authors: Jordao E. P. , de Oliveira A. R. 
Published: May 2018

The incorporation of oil base mud cutting from drilling operations within the manufacture of clay bricks, is considered as one alternative for reuse and final disposal of the OBMC. To evaluate such alternative, on site OBMC amended bricks were produced (15000 bricks at Plant “A”, in Rio Bonito, RJ, and 4000 bricks at Plant “B”, in Jundiai, SP). Plant “A” produces 100000 bricks per day, and Plant “B” 40000; in both plants the cuttings were added in controlled amounts to the normal clay used in the manufacture process.
The on-site experiments included the production of conventional bricks, 2.5% and 5% amended bricks. The laboratory tests included:–properties, leachate, and solubilization tests of the cuttings;–leachate and solubilization tests of the normal and OBMC bricks;–compression strength of the normal and OBMC bricks.
The paper describes the process employed in the brick manufacture and the laboratory experiments. It also presents the properties of the OBMC bricks, and the benefits to both the manufacturer and to environmental control programs.
Performance of the 5 MLD UASB Reactor for Sewage Treatment at Kanpur, India
Authors: Draaijer H. , Maas J. A. W. , Schaapman J. E. , Khan A. 
Published: May 2018

The present paper describes the performance of a 1200 m3 UASB reactor treating 5000 m3 municipal waste water per day at Kanpur, India. The reactor was constructed in three parallel compartments of 600, 300 and 300 m3 respectively to study the influence of various design and operational parameters on process performance. The 600 m3 compartment is the reference unit. In one of the 300 m3 compartments the effluent overflow gutters are provided with baffles to prevent overflow of floating material. The other 300 m3 compartment is provided with a double amount of inlet pipes at the bottom of the reactor to assess the effect of a more dense distribution of the influent.
The start-up of the reactor was carried out without addition of seed sludge since the influent contained the necessary seeding material.
Data collected over a period of twelve months showed that there was an average reduction in COD, BOD, and TSS concentrations of respectively 74, 75, and 75 % at a hydraulic retention time of 6 hours. Excess sludge production was 0.2 kg TSS/m3 waste water, having 60-70 percent ash. It could be dried in six days on open sludge drying beds. The biogas yield was 0.05 to 0.10 m3/kg COD removed. The gas had 75 to 80 percent methane. Also during winter time the treatment efficiency and process stability remained good. The compartment provided with baffles showed better removal efficiencies for COD, BOD, and TSS than the other compartments. A double number of inlet points did not show an increase in removal efficiency. A density of one inlet point per 3.7 m2 is sufficient to provide a properly distributed influent in the reactor.
Field Investigations on Sediment Occurrence and Behaviour in Brussels Combined Sewers
Authors: Verbanck M. 
Published: May 2018

Although sewer sediments are now widely recognized as a major source of misfunction of urban drainage systems (for both hydraulic and environmental considerations), it is still too infrequent that priority of research activities in this area is given to field studies. The measuring campaigns conducted since 1986 in the drainage system of Brussels-North have been focused on sedimentation processes in the major sewer lines. There is an obvious distinction to be made between solids constituting the sediment bed of a man-entry sewer, which are relevant for its hydraulic capacity, and the ones contributing to the pollutional impact of CSOs upon receiving waters.
The material which is removed several times a year from the main trunk sewer of Brussels is coarse, granular and has a low environmental impact, notably because of its limited mobility. This appears to be due to a very efficient granulometric grading, as a result firstly of the retention of the coarsest solids in highly selective gully-pot inlets, and secondly of an elutriation process removing from the sediment bed all fine organic-rich particles during daily peak flows.
There is evidence to show that the build-up of the sediment bed in these large-sized sewers is driven by a bed-load process (active even during dry spells), while the solid material responsible for the detrimental effects of CSOs (which is much finer) is primarily transported through wash-load and suspended-load.
Presence of Indicators and Salmonella in Natural Waters Affected by Outfall Wastewater Discharges
Authors: Moriñigo M. A. , Muñoz M. A. , Cornax R. , Martinez-Manzanares E. , Borrego J. J. 
Published: May 2018

The presence of the pathogenic microorganism Salmonella as well as indicator microorganisms (total and faecal coliforms, faecal streptococci, Clostridium perfringens, and coliphages) was investigated in three different aquatic environments affected by sewage discharges. The relationships between indicators and Salmonella depended mainly on the source of faecal discharges and on the survival capability of the microorganisms in aquatic environments. The microorganisms most closely related to Salmonella spp were faecal coliforms and C. perfringens, the latter yielding also the highest linear regression slope value. Detection percentages of Salmonella spp were high even at a low level of pollution, which allowed detection of the pathogens in the absence of classical indicator microorganisms in the sample.
The results obtained in the present study showed that there were no differences in survival rates between the serotypes of Salmonella tested. Moreover, Salmonella spp exhibited a similar persistence to E. coli in aquatic ecosystems, particularly in marine environment.
Anaerobic Biofiltration versus Aerobic Membrane Filtration: Comparison on a Difficult Substrate
Authors: Sauvegrain P. , Tazi-Pain A. , Rogalla F. , Valter F. 
Published: May 2018

Several methods were compared to treat heat treatment liquor on a municipal wastewater treatment plant, to reduce loading and allow upgrading.
To ensure low suspended solids in the return flows, granular anaerobic filters were chosen in parallel with membrane treatment:–an upflow wood-based charcoal anaerobic filter–an upflow floating polystyrene anaerobic filter–an aerobic reactor (activated sludge) coupled with microfiltration.
Very similar loading rates and removal efficiency was obtained with the anaerobic filters; they allow to treat highly concentrated effluents in a detention time of 10 h but COD removal efficiency was limited to 60%.
The higher contact time of up to 7 days in aerobic treatment, coupled with microfiltration, achieves elimination of 85% of COD and 95% of BOD. Nevertheless, loading rates and biomass concentrations remained low and flux on the membranes was heavily restricted.
Biological Denitrification System with Membrane Separation for Collective Human Excreta Treatment Plant
Authors: Magara Y. , Nishimura K. , Itoh M. , Tanaka M. 
Published: May 2018

In Japan there are about 1200 collective night-soil treatment plants which treat about 42,700,000 population equivalent of night soil and 30,000,000 population equivalent of on-site treatment tank sludge. A sophisticated night-soil treatment system has been developed which uses ultramembrane filtration for the solid-liquid separation stage in a biological denitrification process devised by a joint research and development project between the governmental research institute and a number of private industries.
The effluent from the new system can be anticipated to have levels of BOD, SS, COD, T-N and T-P of about 5 mg/l, 0 mg/l, 35 mg/l, 20 mg/l and less than 0.3 mg/l, respectively. The investment and operational cost of the new system is less than or equivalent to a conventional biological denitrification plant. Furthermore the new system has the advantage of requiring less land and fewer operators. Because of these advantages the new system, i.e. a high-rate biological denitrification process with ultramembrane filtration, is going to be the major system for collective night-soil treatment plants in Japan.
Alternative Options for Atrazine: Incidence on Water Treatment Device
Authors: Montiel A. , Weité B. 
Published: May 2018

In recent years, triazine residues are often evidenced in surface waters as well as in underground waters. The European standards for the maximal level of each pesticide in water for human consumption is 0.1 µg.l−1 which raises problems for triazines such as atrazine or simazine.
New molecules have been designed to replace atrazine and the aim of our study is to evaluate on a pilot plant the outcome of two triazines wich could be used instead of atrazine and simazine; these two triazines are cyanazine and terbuthylazine. These triazines are not removed by coagulation, floculation, decantation. Cyanazine is well eliminated by slow sand filtration. Ozonation has no effect on cyanazine but eliminates 40 % of terbuthylazine. Mechanism of elimination of terbuthylazine on slow sand filters seems to be reversible adsorption which can lead to re-release of this pesticide in case of variation of concentration in the influent water.
Influence of the Drainage Basin input on a Pathogenic Bacteria (Salmonella) Contamination of a Mediterranean Lagoon (The Thau Lagoon - France) and the Survival of This Bacteria in Brackish Water
Authors: Galès P. , Baleux B. 
Published: May 2018

Research has been carried out over a 10 month period with the aim of identifying potential sources of Salmonella contamination in a Mediterranean lagoon (the Thau Lagoon). Two types of source have been sampled, permanent ones which are checked monthly, and incidental ones.
The highest occurrence of Salmonella is linked to episodic events brought on by rainfall. After summer low water levels, the rising of river water brings back into circulation water from pools previously formed by waste water from sewage treatment plants and sediments, thus creating a significant source of bacteria. The sewer system can also supply the Thau Lagoon with varying quantities of Salmonella when the system breaks down, and also when it is overloaded by an excess of rainwater following a storm. Monthly checks reveal that discharges of Salmonella occurred occasionally in permanent inputs, whereas the outflow from the Mèze pond provides a quasi-permanent, but negligible, source of contamination. The major risk of shellfish breeding contamination is thus associated with rainfall, and the occasional overflow of raw wastewater.The survival of Salmonella in the lagoon waters varies in function with the seasons, and the risk is greatest at those times of the year when autopurification can be affected.
The Removal of Chlorinated Organics from Conventional Pulp and Paper Wastewater Treatment Systems
Authors: Bryant C. W. , Avenell J. J. , Barkley W. A. , Thut R. N. 
Published: May 2018

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

Spent bleaching effluents (from chlorination (C) and extraction (E) stages) of a sulfate pulp mill were subjected to bench-scale biological and advanced treatment.
Although &gt; 90 % of the influent BOD5 could be removed in an activated sludge process, the effluent still contained high amounts of resistant substances. The maximum COD removal was about 50 %; the removal rates achieved in the parameters TOC, DOC, AOX, SAK (254 nm) were even lower. The biological treatment led to an increase in color (436 nm) up to 40 %.
The biologically pretreated effluent was further treated by ozone or ozone/irradiation. The DOC, COD, color (436 nm), SAK (254 nm) and AOX removal rates amounted to 61 %, 81 %, 98 %, 92 % and 92 %, respectively. These methods led simultaneously to an increase in biological biodegradability as reflected by an increase in BOD5. A comparison of the results obtained for raw and biologically pretreated wastewaters showed that biodegradable substances should first be removed from the wastewater since otherwise the effectiveness of these methods decreased.
The coagulation/flocculation of biologically pretreated effluent showed that FeCl3 was the most effective coagulant and that removal rates &gt; 90 % could be achieved. The treatment with various powder activated carbons showed that a dosage of 10 g/l was required to achieve elimination rates &gt; 90 % in the parameters DOC, COD, color (436 nm) and SAK (254 nm). Adsorption isotherms were developed for every activated carbon and adsorption constants were calculated.
Improved Biological Nitrification Using Recirculation in Rotating Biological Contactors
Authors: Klees R. , Silverstein J. 
Published: May 2018

The effect of recirculation on biological nitrification in rotating biological contactors (RBCs) was examined in an on-site pilot-scale RBC system which simulated full-scale plant RBC operations at the Longmont, Colorado, Wastewater Treatment Plant (LWWTP). Two LWWTP wastewater streams were used as pilot RBC influent. One wastewater stream, designated the “fresh” influent, was first stage trickling filter effluent. The second stream, designated the “recirculation” influent, was clarified secondary effluent. Three recirculation ratios, defined as the ratio of the recirculation influent to the fresh influent, were examined: 0 (no recirculation), 1 (50% of the flow is recirculation), and 3 (75% of the flow is recirculation). Each recirculation ratio was studied at three hydraulic loading rates.
Recirculation improved nitrification at all hydraulic loading rates. Improved nitrification with recirculation was due to the dilution of influent biodegradable organic carbon (BOD5) which occurs as a result of mixing secondary plant effluent with first stage effluent. An unexpected and operationally significant result was that extremely low concentrations of influent organic carbon did not improve nitrification.
Nitrogen Reduction – Volume Demand
Authors: Palmgren T. 
Published: May 2018

Due to the slow growth of nitrification bacteria at low temperatures, nitrogen reduction normally requires long hydraulic retention time during winter. Important for the nitrification process is the aerated sludge age. Factors influencing the sludge age are aerated volume, mixed liquor suspended solids concentration, organic loading and sludge yield. In an existing plant you cannot easily expand the volume and the load is difficult to decrease. But the suspended solids concentration can be increased by running the biological step with the contact stabilisation process.
At the Käppala Association sewage treatment plant in Lidingö just outside Stockholm, one of the six aeration tanks has been reconstructed for full scale nitrogen removal experiments. In this tank the old aeration system has been replaced with rubber membrane diffusers. Further more there are several zones separated by walls in the tank. The tank can thereby be run with great flexibility. By running it with the contact stabilisation process, the sludge age has been improved by a factor between 1.5 and 2 and thereby it succeeds in keeping the nitrification bacteria in the system even during snow melting. At temperatures of about 9 °C and hydraulic retention times of less than 3 hours in the contact zone there has been a nitrification degree of up to 50 to 60 %. The experiment was conducted with a stabilisation zone of up to half the total volume of the aeration tank.
The main purpose for the experiments during the winter seasons was to improve nitrification. Keeping the nitrifiers in the system had been a crucial problem during previous years. When the nitrifiers were lost with an increased flow and decreased temperature the nitrification process didn't restart until the temperature was increased and the load decreased. Usually this didn't occur until the middle of the summer meaning a loss of nitrification for up to six months.
In Sweden there is a goal set for 50 % nitrogen reduction for the plants in the Stockholm region. At Käppala we manage to keep 60 to 70 % nitrogen reduction during the warm season, that is from July to December. If we can keep up the nitrification the whole year we can achieve 50 % as a yearly average under normal conditions even though we can't keep the nitrogen reduction rate as high during the cold season.
Full-Scale Application of Nitrogen Removal with Methanol as Carbon Source
Authors: Nyberg U. , Aspegren H. , Andersson B. , Jansen J. la C. , Villadsen I.S. 
Published: May 2018

In Sweden many advanced sewage treatment plants for BOD and phosphorus removal have to be extended with nitrogen removal. Due to existing plant configuration and wastewater composition, denitrification with supply of an external carbon source can be a cost-effective solution in many cases.
At the Klagshamn wastewater treatment plant in Malmo investigations for extensive nitrogen removal have been made in a single-sludge system with pre-precipitation and post-denitrification where methanol was added for denitrification. Results from the tests showed that a high level of nitrogen removal can be reached, and that the process was stable and easy to operate. The process application gave less supplementary cost for an extended nitrogen removal than for upgrading the plant with larger basin volumes.
In order to examine the purification performance caused by the addition of methanol, the starting period was followed extensively with online nitrate sensors and daily composite samples. The development of the denitrif ication capacity of the sludge with methanol and acetate as carbon sources was followed and microbiological changes were examined microscopically.
Complete denitrification was obtained after approximately one month at 10°C. The denitrification capacity of the sludge with methanol reached that of acetate after about the same time. The microscopic examination revealed a growing population of budding and/or appendaged bacteria, presumably Hyphomicrobium spp, reaching a stable maximum at the time when optimal nitrate removal occurred.