bluuebunny/crossref_metadata_2025 huggingface dataset:
The control of septicity and odours in sewerage systems and at sewage treatment works operated by Anglian Water Services Limited
Authors: Sercombe Derek C. W.
Published: May 2018

The paper gives reasons for and an overview of the septicity and odour control efforts of Anglian Water Services. It outlines the chemicals available and indicates some practical dosages. A comparison is given of types and number of installations and changes which have taken place since 1979. The paper describes an example of bioaugmentation to control hydrogen sulphide formation and the effective use of bioscrubbers and ozone for the treatment of malodorous air. Treatment costs are discussed. It is concluded that our better understanding of the mechanisms involved has led to an increase in the use of nitrate salts. A combination of chemical dosing systems may be necessary to prevent septicity and eliminate malodorous compounds.
The fate of detergent surfactants in sewer systems
Authors: Matthijs E. , Debaere G. , Itrich N. , Masscheleyn P. , Rottiers A. , Stalmans M. , Federle T.
Published: May 2018

The fate of detergent surfactants in the sewer can be studied both in laboratory tests and in field experiments. The laboratory studies can be used to determine the rate of disappearance of a test molecule as a function of residence time and estimate its half-life in a given habitat. In addition, important information can be obtained on the mechanism of degradation. Field studies can determine the actual environmental concentrations of surfactants in raw sewage which can then be compared with the expected concentration based on consumption volumes. The difference between the measured and predicted concentration provides an estimate for the disappearance of the test chemical during its travel in the sewer and confirms the results of the laboratory tests.

This paper focuses on the fate of a number of important representative anionic, nonionic and cationic surfactants, in the sewer. The results of laboratory die-away studies showed that, in general, the half-life for disappearance in the sewer was in the order of hours for Fatty Alcohol Ethoxylate (AE), Fatty Alcohol Ethoxy Sulphate (AES) and Di-Ethyl-Ester Di-methyl-Ammonium Chloride (DEEDMAC). These laboratory findings for AES were confirmed by monitoring actual raw sewage reaching municipal sewage treatment plants. In addition, a field study demonstrated that the concentration of glucose amides (GA) is considerably reduced during its travel in the sewer. These complementary laboratory and field studies provide key information for the safety assessment of surfactants. They demonstrate that the concentration of surfactants can be significantly reduced in the sewer resulting in a rapid reduction of the environmental loading, which is particularly important in environmental situations where inadequate or no sewage treatment exists.
Aggregation of sulphate-reducing bacteria and homo-acetogenic bacteria in a lab-scale gas-lift reactor
Authors: van Houten R. T. , van Aelst A. C. , Lettinga G.
Published: May 2018

This paper discusses aspects of the formation, growth and detachment of sulphate-reducing aggregates, growing on H2/CO2 and H2/CO gas mixtures in a 4.5 L lab-scale gas-lift reactor. The biomass in the aggregates consisted predominantly of Desulfovibrio sp. and Acetobacterium sp.

Our experiments with H2/CO2 showed that aggregates with pumice particles, i.e. biofilms, as well as carrier-free aggregates were formed. At pH 7.0, all the aggregates had a very hairy structure. This structure, however, was pH dependent. At lower pH-levels the aggregates became smooth. At pH-values higher than 7.0 the hairy structure became even more irregular. The predominant microorganisms were rather heterogeneously distributed throughout the aggregates at all pH-values.

Growth on gas-mixtures of H2/CO led to the formation of smooth aggregates. Presence of CO also led to formation of a layered biomass structure in which the Acetobacterium sp. were more at the outside of the aggregates and the Desulfovibrio sp. were located at the inner part of the aggregates.

The observed changes in the surface structure of the sulphate-reducing aggregates are related to the growth rate of the microorganisms present. A high growth rate yields a rough and hairy aggregate surface. A low growth rate yields a smooth aggregate surface, since the low growth rate of the microorganisms allows detachment of the large protrusions from the aggregate surface.

The surface structure is not dependent on the type of bacteria present at the surface, i.e. sulphate-reducing bacteria or homo-acetogenic bacteria.
Evaluating and modelling the kinetics in a full scale submerged denitrification filter
Authors: Janning K. F. , Harremoës P. , Nielsen M.
Published: May 2018

Experimental data in forms of vertical concentration profiles has been provided from a full scale submerged denitrification filter with biocarbone as filter material.

Denitrification rates were determined in full scale under different loads of nitrate and methanol with methanol in excess. Vertical concentration profiles of nitrate and methanol have verified kinetics in the half-order region with removal rate constants in the range of k0.5A = 0.13-0.21 g N0.5 m−0.5 d−1 (0.5 order for partial penetration in the 0 order intrinsic concentration range). The removal rates found are low with methanol as carbon source as compared to information from literature.

The experience with detailed mathematical modelling is that “best fit” can be achieved by different sets of parameters with the computer program AQUASIM. Full scale experiments have to be supplemented with dedicated laboratory scale experiments to determine all important parameters.
Strategies for protecting Florida's everglades: the best management practice approach
Authors: Izuno F. T. , Capone L. T.
Published: May 2018

The Everglades Agricultural Area (EAA) is a small portion of the Everglades region, consisting of an artificially drained area of approximately 280 000 ha of organic soils providing a rich environment for the cultivation of primarily sugar cane, vegetables, rice, and sod. Hydroperiods and excessive nutrients in surface water inflows have been identified as potentially disruptive to the natural ecosystem, with phosphorus (P) deemed to be the limiting nutrient. Hence, agricultural drainage water from the EAA, containing higher than background P loads and concentrations, has been targeted as a source of the problem. To reduce P loads and concentrations in the drainage water leaving farms in the EAA, on-farm best management practices (BMPs) can be used. These BMPs have been identified and tested at the large plot scale and are presently being implemented and their efficacy verified at the farm level. It is currently estimated that P loading from the EAA can be reduced by 20% to 60% using BMPs. A 45% reduction should be attainable while keeping within acceptable cost/benefit ratios. The use of BMPs, however, will require higher levels of farm management and more sophisticated tools for decision-making.
Influence of the microbial content of different precursory nuclei on the anaerobic granulation dynamics
Authors: El-Mamouni R. , Leduc R. , Costerton J. W. , Guiot S. R.
Published: May 2018

Anaerobic granule nuclei enriched in either acidogens (AF), syntrophic consortia (SN), Methanosaeta spp. (MT) and Methanosarcina spp. (MN) were developed in four upflow bed filter reactors fed with sucrose, an ethanol/acetate mixture, acetate and methanol, respectively. The four developed granule nuclei presented different settling velocities: 3.2, 8.7, 10.5 and 11.3 m/h for the AF flocs, the MS-, the SN- and the MT-nuclei, respectively. The ash content represented 60%, 40%, 30% and 16% of dry weight for the MT-, MS-, SN-enriched nuclei, and AF flocs, respectively. Acidogenic flocs contained high amount of extracellular polymeric substances.

The influence of these four different nuclei on the time course of complex granule development was investigated by shifting the feed carbon of all of the four reactors to sucrose. Granulation proceeded rapidly both on syntrophic and Methanosaeta nuclei. The largest granules (Sauter diameter of 2.36 mm), however, were obtained within the shortest period in the reactor started with syntrophic nuclei. These nuclei presented also the best colonization by fermentative bacteria as shown by the evolution of their glucotrophic activities. Less satisfying granulation was obtained on Methanosarcina nuclei. In contrast, granulation was significantly retarded when acidogens were used as precursors. From these results it appears that syntrophs and Methanosaeta spp. play the principal role in anaerobic granulation process.
Effect of pH on metals precipitation in denitrifying biofilms
Authors: Liehr S. K.
Published: May 2018

The objective of this paper is to present evidence for the possibility of enhanced metal precipitation inside denitrifying biofilms. The pH environment surrounding microorganisms growing in biofilms is frequently different than the environment of the bulk liquid because products of metabolic reactions are limited in their ability to diffuse out of the biofilm. In the case of denitrifying biofilms, the interior pH will be higher than the pH in the bulk liquid, creating conditions that favor precipitation of heavy metals. A theoretical model was used to predict pH inside denitrifying biofilms. Copper and nickel solubities were calculated as a function of pH and alkalinity. Results provide evidence to support the theory that higher internal pH can result in greater metal removal by the biofilms.
Upscaling biomanipulation in 600 ha Lake Zuidlaardermeer
Authors: Roos C. , Klinge M. , Heringa J. , de Vries D. A. , Torenbeek R.
Published: May 2018

In the 600 ha Lake Zuidlaardermeer in The Netherlands enclosure experiments were carried out in order to test the feasibility of biomanipulation. In two enclosures of 625 m2 each the effects of reduction of fish and wind and waves on water chemistry, phyto- and zooplankton and submerged macrophytes were studied and compared to the lake.

In the “fishless” enclosure transparency increased from 40 to 120 cm, chlorophyll-a dropped from 70 to 20 μg/l, total-P dropped from 0.20 to 0.10 mg/l, Daphnia sp. > 1 mm increased from 30 to 130 individuals/l and submerged macrophytes returned. The “fish” enclosure largely behaved in a way intermediate between the “fishless” enclosure and the lake: transparency increased to 60 cm, chlorophyll-a dropped to 40 μg/l, total-P dropped to 0.12 mg/l and Daphnia sp. > 1 mm increased to 80/l. Submerged macrophytes however did not develop.

The experiments show the potential of the lake for ecological rehabilitation. Nevertheless the effect of wind and waves on a larger scale remains uncertain. Therefore plans have been made to build a larger enclosure (40–100 ha). In this way, the effects of fish and wind and waves can be studied on a larger scale while at the same time recovery of the submerged macrophytes within this enclosure will be a significant step towards ecological rehabilitation of the whole lake.

Beside the return of the submerged macrophytes the management is also aimed at the development of substantial amounts of emergent vegetation, thus supporting enough Northern Pike (Esox lucius L.) for regulation of the planktivorous fish community.
Water quality management: can we improve integration to face future problems?
Authors: Somlyódy László
Published: May 2018

Water (and its deteriorating quality) may be the most severe stress on the exponentially growing human population in the next century. Problems are becoming increasingly complex and diverse and require more and more specific knowledge, and efficient integration across various disciplines, sectors, countries, and societies. The major challenge addressed is whether we are prepared to realize the desired integration and to resolve the large amount of existing gaps and barriers. The paper analyzes major past and desired future trends in water quality management. A number of issues are selected such as the identification, occurrence, and perception of various problems (e.g. eutrophication, acidification, global warming), pollution control types, wastewater treatment, modeling and monitoring, planning and environmental impact assessment, legislation and institutions, the notion of sustainable development, and the role of science and engineering. The past two decades showed tremendous developments in water quality management. In spite of these, the focus of the present discussion lies mostly on pitfalls to disseminate lessons and questions which are crucial to likely future problems and desired improvements.
The water system explorations – a new dutch project (the aquatic outlook) for combining monitoring, research and policy analysis for integrated water management
Authors: Luiten J. P. A.
Published: May 2018

Sustained development is the target of almost every modern policy dealing with the aquatic environment. Sustainability is focused on human life, but also on the ecological quality of our environment. Both aspects are essential for life on earth.

The ecological quality of aquatic systems can be expressed by biotic and abiotic parameters. Monitoring and research give information about these parameters and a comparison with the targets brings us to the necessity of supplementary policy-measures.

Human activities are considered to be the cause of the environmental problems. All kinds of social and economical activities influence the water bodies. Reaching the goals is only possible if human influence on environment is changed or reduced.

Within a catchment area, relations could be laid between human activities and ecological problems in the reception areas. Policy analysis is especially looking for the most efficient way to remove the bottlenecks. For an effective policy analysis in river catchment areas the following elements are essential:

– quantitative data; monitoring programs have to consider more than ever the ecological aspects of policy analysis;

– the determination of target values (probably by means of laboratory experiments);

- knowledge about the factors causing violation of the targets;

– an inventory of measures for influencing the existing or future situation;

– sufficient knowledge about the relation between the measures and (i) the ecological parameters and (ii) the social and economical activities in society;

– a policy analysis for defining future policies;

All of these studies will generate many data; to present these in a clear and succinct manner is one of the goals of the project “The Aquatic Outlook”.
Water quality conservation for the Citarum River in West Java
Authors: Bukit Nana Terangna
Published: May 2018

The Citarum River in West Java has important role in the economic development and prosperity of the people in West Java Province and Jakarta City. It has been exploited to support agriculture, fisheries, public water supply, industry, hydroelectric power and recreation. More than 500 industries and about five million people in the basin are the main sources of water pollution of the Citarum River. The continuing deterioration of water quality in the Citarum River has become a routine water pollution case. Therefore it is necessary to solve the river pollution problems and upgrade the water quality. A study on water quality management of the Citarum River was executed from 1989 to 1993. The objective was to define the recommendation for the optimisation of water quality conservation. The results of the study show that the quality at most locations of the river during the dry season has exceeded the water quality objectives for its beneficial water uses. It is recomended that the domestic and industrial pollution load has to be reduced for water quality conservation. Smaller unit domestic waste treatment and centralised industrial waste treatment are recommended for pollution control. For further development it is recommended to propagate clean technology and to prefer giving licences to industries with low water demand. Regular monitoring must be carried out for effective water quality control.
Microstructural analysis of UASB granules treating brewery wastewater
Authors: Fang H. H. P. , Chui H. K. , Li Y. Y.
Published: May 2018

The microstructure of granules from a full-scale UASB reactor treating brewery wastewater was examined using light microscopy as well as the scanning and transmission electron microscopies. The granules typically have a complex, layered structure. The outer layer of the granule was densely packed with various types of bacteria, including cocci, bacilli, Methanosarcina, and Methanothrix. The second layer was composed of a matrix of Methanothrix with two types of microcolony showing evidence of syntrophic associations between hydrogen-producing acetogens and hydrogen-consuming methanogens. The interior of the granule, on the other hand, was predominantly Methanothrix with scattered microcolonies of syntrophic associations, which became sparse and disappeared toward the centre core of the granule.
Development of a high-efficiency household biofilm reactor
Authors: Imura M. , Sato Y. , Inamori Y. , Sudo R.
Published: May 2018

Household wastewater treatment plants have been rapidly promoted in recent years as part of the measures for reducing the pollution loading discharge from private households in Japan. The authors have developed a high-efficiency household wastewater treatment plant employing a flow equalisation anoxic-oxic recirculation biofilm process removing organic matter as well as nitrogen which causes eutrophication. A full-scale experiment has been conducted for one year by leading actual grey water (cooking, bathing, washing effluents) from a private household into the experimental apparatus. The results obtained in this study are summarised as follows: effective flow equalisation and excellent effluent quality were achieved, the maximum effluent flow rate was 100 l/h (the peak coefficient 1.5) when the maximum influent flow rate was 415 l/h (the peak coefficient 6.2), the average values of BOD5, CODMn, SS, T-N and T-P of the treated water were 7.8 mg/l, 11.1 mg/l, 5.9 mg/l, 6.4 mg/l and 1.2 mg/l, respectively BOD5 and T-N of the treated water were less than 10 mg/l during the experimental period.
Modelling waste output from trout farms
Authors: Frier J.-O. , From J. , Larsen T. , Rasmussen G.
Published: May 2018

The aim of waste modelling in aquaculture is to provide tools for simulating input, transformation, output and subsidiary degradation in recipients of organic compounds, nitrogen, and phosphorus. The direct purpose of this modelling is to make it possible for caretakers and water authorities to calculate waste discharge from existing and planned aquaculture activities. A special purpose is simulating outcome of waste water treatment and altered feeding programmes. Different submodels must be applied for P, N, and organics, as well as for the different phases of food and waste treatment. Altogether this calls for an array of co-operating submodels for a sufficient coverage of the options. In all the required fields there is some scientific background for numerical model approaches, and some submodels have been proposed. Because of its multidisciplinary character a synthesized approach is still lacking. Within trout farming this work attempts to establish the different submodels and outlines future possibilities for synthesizing the knowledge to a numerical model.
Requirement for phosphorus in rainbow trout (oncorhynchus mykiss) growing from 50 to 200 g
Authors: Rodehutscord M. , Pfeffer E.
Published: May 2018

Semi-purified diets containing 19.6 MJ digestible energy/kg dry matter were fed to groups of rainbow trout initially weighing, on average, 53 g/trout. In a series of 12 diets, mono sodium phosphate replaced a silica carrier aiming at a range in P concentration from 1.0 to 10.9 g/kg dry matter. Each diet was fed to a group of 20 trout. During the trial of 53 feeding days, response of dry matter intake, weight gain, feed conversion ratio and P concentration of the gain followed exponential functions. For achieving 95 % of the potential maximum gain, a dietary concentration of 3.7 g P per kg dry matter was required. However, 5.3 g P per kg dry matter were required for achieving high P concentration in the gain. P was utilized most efficiently at a dietary concentration of 2.5 g/kg dry matter. A dietary P concentration of 0.25 g available P per MJ digestible energy was recommended to be sufficient for trout diets.
19th century and early 20th century studies on aquatic off-flavours - a historical review
Authors: Persson Per-Edvin
Published: May 2018

A review of the 19th century and early 20th century literature reveals that a largely correct picture of the role of many microalgae as sources of tastes and odours in water supplies had been obtained by the end of the 19th century. Attention was not paid to actinomycetes as an odour source until the end of the 1920s. Scientific studies on the etiology of off-flavours in fish began in 1910, revealing an essentially modern picture from the beginning.
Management of wastewater from the fertilizer industry
Authors: Abou-Elela S. I. , El-Kamah E. M. , Aly H. I. , Abou-Taleb E.
Published: May 2018

Two schemes of treatment were applied to wastewater produced from a superphosphate manufacturing unit. In the first scheme the final effluent, comprising washing water from the scrubbing towers in combination with cooling water, was subjected to chemical coagulation-sedimentation using lime. In the second scheme the washing water from the scrubbing towers was chemically treated with recycling of a percentage of the treated effluent. The two treatment schemes were carried out using a continuous flow compact unit. The results obtained revealed that chemical treatment of washing water from the scrubbing towers including recycling treated effluent waste (with a ratio of 1:2) was recommended. The treatment process proved to be very efficient in removing fluoride, phosphate, silicate and suspended solids. Also, the optimum conditions required for drying the sludge using sludge drying beds were determined. Analysis of the dry sludge indicated that it can be reused with the initial raw material in the plant. A process design of the proposed treatment plant was also included.
Evaluation of daqahla wastewater treatment plant, aerated lagoon and ponds system
Authors: El Sharkawi F. , El Sebaie O. , Hossam A. , Abdel Kerim G.
Published: May 2018

In Egypt, Daqahla wastewater treatment plant (WTP) includes two anaerobic ponds, one aerated lagoon followed by three maturation ponds. It started operation in 1989. This plant is chosen as an example for evaluation as a cost-effective method for wastewater treatment in rural areas.

A sanitary survey, laboratory analysis and cost survey were carried out during the period between December 1991 to September 1992. It was found that Daqahla community has high strength wastewater characterised by an average BOD5 of 454 mg/l and average SS of 508 mg/l. Furthermore, it was noticed that Daqahla WTP was loaded with an actual flow (833 m3/d) higher than the design flow (520 m3/d). In addition there was a wide fluctuation in the loads applied to the system. The system was evaluated, and the average removal efficiencies of suspended solids, BOD5 and COD were 92%, 95% and 93% respectively. While there was no removal of ammonia and phosphate, with respect to the efficiency of the anaerobic ponds, it was noticed that about 50% of the organic loading was removed and this is consistent with the literature. In order to upgrade the efficiency of the aerated lagoon and the first maturation pond, the design load and detention time must be taken into consideration. Sludge removal processes must be considered since the first maturation ponds was working as a settling pond. It was noticed that the second and the third maturation ponds were working as facultative ponds. To upgrade their efficiencies, the actual organic loading must not exceed the design load with a minimum retention time of 3 days per pond.

The cost survey indicates that the construction cost is 63 LE/cap. Land costs in delta and desert areas are 19 and 2 LE/cap., respectively (acre prices in delta and desert are 40000 and 4000 LE respectively. Total construction cost in the delta is 82 LE/cap., while in the desert, the total construction cost is 65 LE/cap. Furthermore, the operation and maintenance cost is 12 LE/cap. year.
Interactions between bacteria-free Anabaena macrospora clone and bacteria isolated from unialgal culture
Authors: Aoyama K. , Kawamura N. , Saitoh M. , Magara Y. , Ishibashi Y.
Published: May 2018

Cyanobacteria are accompanied by many bacteria in the mucus zone of the vegetative cell. A strain of Anabaena macrospora (A. macrospora) producing an earthy-musty odor was isolated from Lake Biwa together with 28 isolates of bacteria. Based on preliminary test results, 18 isolates were selected for incubation in a one-tenth Tripto-soy broth solution, and their genera and species were identified. Four isolates belonged to Alcaligenes, nine to Pseudomonas, four to Moraxella and one was not identified. Four isolates, Alcaligenes sp., Alcaligenes eutrophus, Moraxella sp. and Alcaligenes faecalis (A. faecalis) had a direct influence on the growth of A. macrospora and geosmin production. As the multiplication of bacteria was faster than A. macrospora, the consistencies of the bacteria cells and the period of bacteria addition had no influence on the final growth of A. macrospora and geosmin production.
Composting of sewage sludge in a rotating vessel
Authors: Fürhacker M. , Haberl R.
Published: May 2018

Composting of sewage sludge can enhance its quality and suitability for agricultural use. In this work the optimal conditions for composting sewage sludge of small domestic wastewater treatment plants in a rotating vessel with the aim of sanitary safety were investigated. An intensive control programme with regard to viruses, bacteria and parasites was carried out that showed that the hygienic quality was satisfactory.

A second aspect was the investigation of a possible reduction of hazardous organic and inorganic pollutants. The amount of inorganic micropollutants was low and did not change based on inorganic content. Based on inorganic residues, losses of 15.7% of the AOX and 25% of the EOX could be found. Relatively high decreasing rates of detergent concentrations could be measured. Only 31.1% of the original load of anionic detergents (measured as MBAS), 38.7% of the cationic and 57.4% of the non-ionic detergents could be detected in the end material. For PAH concentration reduction between 31.5% of fluoranthene and 90.6% benzo(a)pyrene can be reported. All values are based on the inorganic residues.

The quality of the resulting compost showed in the plant test a growth rate which qualified the compost to be used to increase soil quality.
A demonstration of wastewater treatment for reuse applications in fish production and irrigation in Suez, Egypt
Authors: Shereif M. M. , El-S. Easa M. , El-Samra M. I. , Mancy K. H.
Published: May 2018

About 400 m3/d of raw sewage from the City of Suez were diverted and treated by two parallel pond systems. The first treatment system was conventional Waste Stabilization Ponds which included anaerobic, facultative, and maturation compartments for a total residence time of 21 days. The second system included a series of four plankton ponds with a total residence time in the order of 26 days. The effluent from these inexpensive, but yet effective treatment technologies, was found to conform to the World Health Organization (WHO) standards for unrestricted agricultural and aquacultural applications. The treated waste effluent was successfully used to grow two types of local fish, i.e.Oreochromis niloticus and Mugil sehli. Fish production, without supplemental feeding or pond aeration, reached 5-7 metric tons/hectare/year. Furthermore, the fish were found to be free from human parasites and safe for human consumption. The nutrient rich effluent from the fish pond was further used to grow trees and cultivate certain types of crops, i.e. barley, maize, beets and ornamental plants. This study clearly demonstrates the effectiveness and benefits of waste stabilization ponds systems for low cost treatment of domestic waste and the combined reuse in aquaculture and agriculture applications. In addition, the unique treatment/reuse facilities constructed at Suez will continue to function as an experimental station and serve scientists and engineers to study and to plan applications in Egypt and the region.
Effective removal of musty odor in the Kanamachi Purification Plant
Authors: Muramoto S. , Udagawa T. , Okamura T.
Published: May 2018

Since 1972, the Kanamachi Purification Plant has been faced with a “musty odor” problem in water. In 1984, the plant began to treat raw water with powdered activated carbon. However, the concentration of the musty odor substance 2-methylisoborneol (MIB) in raw water varied so markedly that it was difficult to control the dosage of powdered activated carbon. To achieve a more stable and effective removal of the musty odor, the Bureau decided to introduce an Advanced Water Purification system combining ozonation and biological activated carbon (BAC) treatment. On June 25, 1992, we started operation of the facilities. This system, which is the first of these plants in Japan, can remove musty odor to the satisfaction of the customer.
The use of reference materials in sensory analysis
Authors: Krasner S. W.
Published: May 2018

In descriptive sensory techniques, reference materials are used to establish a common vocabulary for various aromas and flavors. A reference standard can be any chemical or natural material that adequately represents the particular characteristic described. This paper evaluates the utility of various reference materials that have been proposed as odor standards. The odor reference library used included odors commonly attributable to microbiological and industrial sources. The results of utilizing reference standards demonstrated that some materials were very good; that is, they yielded a distinctive odor that transcended cultural and language differences, as well as different levels of experience. Other aromas required several standards to distinguish among subtle but important differences, e.g., geosmin and 2-methylisoborneol to differentiate earthy/musty odors. These standards also included natural materials prepared in various states to reference different types of common odors in water - for example, grass clippings (in water) that had been freshly cut to represent a grassy odor, or had been held for a week to represent a septic odor, as well as dried grass for a hay odor. Other reference materials yielded bimodal distributions in which, primarily, two groups centered around different descriptors; these kinds of materials would not make good reference standards.
Respirometric evaluation of the biodegradability of confectionary wastewaters
Authors: Orhon D. , Yildiz G. , Ubay Çokgör E. , Sözen S.
Published: May 2018

Confectionary effluents are typical examples of strong wastes of biodegradable nature, quite suitable for respirometric analysis. Three different confectionary effluents have been subjected to a treatability-oriented characterization, mainly by means of respirometric methods, yielding meaningful results on COD fractionation and significant kinetic coefficients. Experimental values have been tested by a multi-component mathematical model using the endogenous decay approach and hydrolysis rate constants corresponding to the slowly biodegradable COD fractions have been evaluated using curve fitting.
Sources of nutrients in wastewater from integrated cattle slaughterhouses
Authors: Johns Michael R. , Harrison Michael L. , Hutchinson Philip H. , Beswick Peter
Published: May 2018

The generation of the nutrients, nitrogen and phosphorus, by various process areas of two large, integrated cattle slaughterhouses was studied to assist the better management of wastewater production and treatment. The Dinmore slaughterhouse, located near Ipswich, processes predominantly grass-fed cattle, while the Beef City slaughterhouse west of Toowoomba processes grain-fed cattle. Nitrogen in the wastewater streams largely originated from the rendering plant (50% of the total daily generation at Dinmore and 62% at Beef City), the decreased cattle bone process at Dinmore (22%) and the cattle holding yards at Beef City (32%). Phosphorus was generated primarily in the offal, paunch and tripe processing area at Dinmore (49%) and the holding yards at Beef City (57%). Nitrogen was present mostly as organic or ammonium nitrogen, whereas ortho-phosphate was the main form of phosphorus present in wastewater streams. Significant differences were found in nutrient generation between the two slaughterhouses, with the Dinmore plant releasing almost twice the quantity of nitrogen, and four times more phosphorus, per animal processed compared to the Beef City plant. These results will assist management in allocating resources aimed at cleaner production by minimising and removing nutrients in the wastewater.
Waste stabilization ponds in France: a report on fifteen years experience
Authors: Racault Y. , Boutin C. , Seguin A.
Published: May 2018

In 1992, a survey was conducted on the performance of waste stabilization ponds in France. The data selected come from a sample of 178 ponds, with an average capacity of 600 p.e., throughout France. For each plant, one or several input--output load measurements over a 24-h period are available. The average organic load level received is approximately 25 kg BOD/ha.d, representing 50% of the nominal load. The quality of the treated water is presented based on the type of sewerage system feeding the ponds. The results appear dispersed, however; in 70% of the cases the concentrations in COD and BOD on filtered samples are under 120 mg/l and 40 mg/l, respectively, and the concentration in TSS under 120 mg/l (discharge standards in France for waste stabilization ponds). The reductions in nitrogen and phosphorus nutrients are on average from 60% to 70%. The influence of different parameters (sewerage system type, organic load, season, age of plant, etc.) was studied. The results appear noticeably worse when the ponds receive wastewater from a strictly separate sewerage system.
Treatment of slaughterhouse wastewater
Authors: Martínez J. , Borzacconi L. , Mallo M. , Galisteo M. , Viñas M.
Published: May 2018

In this paper an evaluation of the effluent treatment plant of a slaughterhouse which processes 650 head of cattle a day is presented. Some problems in the operation of the anaerobic reactor and anaerobic lagoons caused by the presence of fats and suspended solids in the effluent were detected. A flotation system by pressurized air injection was tested at the plant. The fat removal efficiency obtained was 63% and 37% for red water and green water, respectively. In order to improve the hydrolysis of particulate matter, a system of two UASB reactors with recirculation, connected in series, was tested at laboratory scale. Removal efficiency was 77% for soluble COD and 82% for insoluble COD, at a volumetric load of 1.8 kgCOD/m3/d. Based on the results of these studies, several modifications in the treatment plant were proposed.
An integrated system for agricultural wastewater treatment
Authors: Rovirosa N. , Sánchez E. , Benítez F. , Travieso L. , Pellón A.
Published: May 2018

The treatment of agroindustrial wastewaters gives the possibility of noxious pollutant removal which otherwise would deteriorate the ecosystem even more. The construction and start-up of Integrated Systems for the treatment of such wastes allow the reuse of the treated effluents, with the consequent production of useful by-products. Biological processes for the adequate treatment of 300 m3/day of mixed animal and human wastewaters allow also the production of 1200 m3/day of biogas as an energy supplier and a source of CO2 for microalgae culture in a High Rate Algal Pond. On the other hand, it can be possible to recover the digested sludge as biofertilizer and low grade water useful for crop irrigation. The proposed Integrated System also provides the recovery of 8.3 g/m2/d of algal biomass suitable for animal consumption and the removal of an important amount of noxious pollutants with an average efficiency of 80–98% (COD basis).
Wastewater reuse to increase soil productivity
Authors: Jiménez-Cisneros B.
Published: May 2018

Often wastewater is considered a pollution problem. However, Mexican experience shows that it can constitute a way to increase soil productivity. This was demonstrated by the use of the wastewater from the Valley of Mexico, which is a mixture of domestic and industrial discharges and rainfall, for irrigation purposes on a surface of 85,000 ha, being an unique experience worldwide. However, this practice – also applicable to agroindustrial effluents – comprises sanitary risks for which a means of control is proposed herein. The process applied is an advanced primary treatment which, thanks to the newly synthesized polyelectrolytes, employs relatively lower doses of ferric chloride (50 mg/l), alum (110 mg/l) or calcium hydroxide (250 mg/l). With this process the required characteristics (pathogenic organisms and metals) for reusing water in agriculture without negative secondary effects are achieved and soil productivity is maintained.
Ammonia elimination processes in stabilisation and high-rate algal pond systems
Authors: Gómez E. , Casellas C. , Picot B. , Bontoux J.
Published: May 2018

Stabilisation pond (SP) and high-rate algal pond (HRAP) wastewater treatment systems are based on the same processes, but differ in their capacity to remove ammonia. This study analyzes the processes concerning ammonia elimination.

The different factors studied are: (i) light irradiance and temperature, (ii) phytoplankton uptake, and (iii) chemical characteristics affecting ammonia concentration. The variables relevant to these processes have been used in path analysis studies.

Different variables describing the studied processes have been used to quantify the different phenomena. A conceptual model has been developed, and applied to each pond. Path analysis technique has been applied. It is a causal modelling technique. The evaluation of causal models involves theoretical, methodological and statistical analysis. Theoretical considerations have been defined in the list of the processes studied. Methodological considerations involve the variable measurements on a defined time-scale. The statistical aspect consists of the evaluation of structural equation models.

The results of these studies show that the principal phenomena affecting ammonia in SP systems are temperature, pH, and total nitrogen input. In HRAP systems ammonia variability is directly linked to pH, temperature, nitrite and total nitrogen input, and indirectly linked to chlorophyll a concentration and pH.

The percentage of observed variability given by the models (R2 =coefficient of determination) ranges between 46% and 60.8%.
Stabilization ponds with recirculation
Authors: Shelef Gedaliah , Kanarek Adam
Published: May 2018

The first facultative pond in a series of stabilization ponds, or else the first part of a large pond, is sensitive to organic overloading creating anoxic or anaerobic conditions at the pond's surface, resulting in malodors and nuisances. Such adverse characteristics are usually manifested seasonally when climatic conditions change to lower temperatures and/or reduced solar irradiance. The design organic loadings on such ponds are therefore determined by the critical season and they are lowered accordingly. Introducing recirculation of effluent from a later pond in the series (usually from the second or third pond) back to the inlet of the first one, at a ratio of 1.0 - 2.5 (recirculated effluent) to 1 (raw sewage influent), can be most advantageous, as follows: (1) organic loadings on the first facultative pond in the series can reach 400-600 kg BOD5 per hectare per day (khd) during summer time and 300-400 khd as a yearly average, compared with a yearly average of 60-140 khd on ordinary facultative ponds, while still maintaining odor-free facultative conditions; (2) reseeding the first pond with active adapted algal biomass; (3) mixing the influent (which is often septic) with oxygen-rich recirculated effluent, thus enhancing the biological process in the first pond and suppressing septic odors, and (4) the increased inlet flow (by combining influent flow with the recirculated effluent) increases the area of solids (sludge) settling in the first pond. Altogether, the recirculation is manifested by reduced land requirements, better stability in pond operation, improved pond's performance and reduction or elimination of malodors and nuisances. Step feeding of the ponds further accentuates the effect of recirculation. Obviously, recirculation requires pumping (low head), energy, piping and connection to a power supply. The cost of operation and maintenance amount to US $0.01-0.02 per cubic metre of treated wastes. The advantages of recirculation nevertheless significantly outweigh the added costs. The paper describes the experience and data which have been gathered during the operation of 120 hectares of ponds with recirculation in the Dan Region (Greater Tel-Aviv) over a period of almost 20 years.
Drip irrigation with waste stabilisation pond effluents: solving the problem of emitter fouling
Authors: Taylor H. D. , Bastos R. K. X. , Pearson H. W. , Mara D. D.
Published: May 2018

A pilot-scale irrigation scheme was set up in South-West Portugal to investigate the causes of emitter clogging which has been observed when waste stabilisation pond effluents are used for drip irrigation of crops. During field trials over a period of two growing seasons, the operating characteristics of five emitter designs were investigated. Susceptibility of the designs to clogging was compared and the nature of clogging particles was analysed. Those emitters that operated most successfully utilised a long water-path labyrinth to reduce flow to the required level. The operating characteristics of the most effective emitter design are presented in detail. Clogging was shown to result from the deposition and entrapment of sand particles within the emitter labyrinth. Organic material, including pond algae, played a secondary role in the clogging process. Emitter design, rather than water quality, was shown to be the most important factor determining the degree of clogging. It was concluded that pond microalgae alone do not constitute a major hazard to the operation of drip irrigation equipment and that waste stabilisation pond effluents may be safely used for drip irrigation if safeguards are adopted to prevent the contamination of laterals by sand and soil particles. A number of recommendations are made to prevent emitter clogging in future reuse schemes.
Pretreatment considerations for dissolved air flotation: water type, coagulants and flocculation
Authors: Bunker Donald Q. , Edzwald James K. , Dahlquist Jan , Gillberg Lars
Published: May 2018

Pretreatment considerations of coagulant selection, flocculation time and flocculation mixing intensity were studied for two different water supply types, aquatic humic and non-aquatic humic waters of low turbidity. Alum, ferric salts, and various polyaluminium chlorides (PACs) with different chemical properties were all effective in dissolved air flotation (DAF) when used under favorable conditions of dosage, pH, and flocculation time. A stoichiometry was found for the aluminium coagulants between coagulant dose and raw water DOC. Si and sulfate PACs were effective in treating cold waters with short flocculation times of 2.5 to 5 minutes. Flotation performance improved slightly with increasing flocculation mixing intensity. The results suggest that flocculation tanks be designed to produce strong, “pinpoint” size floc particles.
Water resources assessment as the basic tool for sustainable and environmentally sound river basin management
Authors: Miloradov R. M. , Marjanovic P. , Cukic Z.
Published: May 2018

This paper deals with the methodology used for conducting a water resources assessment as the core component of water resources master plans. It is basically a quantitative and qualitative water resources balance (WRB) and an essential element of any short or long-term planning of sustainable and environmentally sound river basin development and management. The use of a water resources management balance instead of the water resources balance (water budget) that includes the water withdrawals and discharges in the balance equation should be favoured in water resources assessment.

By using a water resource management balance, the multiple use of a given volume of water is accounted for so that it is possible to satisfy larger water demands than by using the natural water budget approach. This approach forces planners to look at a much wider scope of alternatives (reservoirs versus water recirculation and conservation for example) to meet the demands and also reinforces the role of water quality in water resources assessment.
Use of a protein phosphatase inhibition test for the detection of cyanobacterial toxins in water
Authors: Ash C. , MacKintosh C. , MacKintosh R. , Fricker C. R.
Published: May 2018

The detection of low concentrations of cyanobacterial toxins is demonstrated in the protein phosphatase assay which relies on the inhibition of enzyme phosphatases.
Bacteriophage removal in water treatment plants
Authors: Jofre J. , Ollé E. , Lucena F. , Ribas F.
Published: May 2018

Presence of bacteriophages was evaluated at different stages of two water treatment plants in order to investigate the usefulness of phages as model organisms for assessing the efficiency of the processes. Bacteriophages tested were somatic coliphages, F-specific coliphages and phages infecting Bacteroides fragilis. The presence of human enteric viruses was determined as well in the raw water, the finished water and in samples taken in the distribution network. Results show that in these particular treatment plants, which include prechlorination, phages infecting B. fragilis are more resistant to the treatment processes than the other two phages studied.
Comparison of F-specific bacteriophage, enterococci, and faecal coliform densities through a wastewater treatment process employing oxidation ponds
Authors: Turner S. J. , Lewis G. D.
Published: May 2018

Over a 12 month period F-specific bacteriophages, faecal coliforms and enterococci were compared as microbial indicator organisms for the quality of a wastewater treatment (oxidation pond) system. Results suggest that enterococci may be the most useful indicator for oxidation pond systems.
Harmonisation of micropollutant monitoring in large international river: Danube
Authors: Literathy P. , Laszlo F.
Published: May 2018

Micropollutants (heavy metals, organic compounds) play an important role in the quality characterisation of surface waters. These pollutants are usually bioresistant, persistent compounds or may undergo biotransformation, photo-oxidation, sometimes resulting in more toxic breakdown products than their parents, or can accelerate dispersion of hydrophobic compounds and mobilisation of heavy metals from the solid phase. Because of multiple introduction of these pollutants along a large, international river, and due to the sedimentation and re-suspension of the particulate matter by the river hydrodynamics, the deposition of the polluting compounds into the bottom sediment may occur far downstream of the discharge. Appropriate micropollutant sampling and monitoring in both the water column and bottom sediment are discussed. It is concluded that the higher the fine fraction in the sample, the more representative the sediment-bound pollutant characterisation. In order to achieve water and sediment quality guidelines and objectives for micropollutants the guidelines and monitoring programmes must be harmonised, including the sampling, sample preparation, analytical and data interpretation methods among the riparian countries along the Danube river.