bluuebunny/crossref_metadata_2025 huggingface dataset:
Stabilization and Disinfection of Sewage Sludge by Two-Stage Anaerobic Thermophilic/Mesophilic Digestion
Authors: Mitsdörffer R. , Demharter W. , Bischofsberger W.
Published: May 2018

The first equipment for two-stage anaerobic thermophilic/mesophilic digestion (55/35 °C) of sewage sludge constructed in Germany in 1987 was investigated during one year of large-scale operation. Stabilization efficiency of this process is higher compared to conventional mesophilic digestion at this plant. Disinfection of sewage sludge during thermophilic treatment in the first stage is up to the demands of German legislation.
The Impact of Storm Sewage Discharges on the Ecology of a Small Urban River
Authors: Seager J. , Abrahams R. G.
Published: May 2018

Intermittent discharges of storm sewage from combined sewer overflows continue to be one of the principal causes of poor water quality in many urban rivers in the UK. Despite the persistent nature of this problem, very little attention has been given to the study of how discharges of varying magnitude, duration and frequency affect the ecological quality of receiving waters. This information is of critical importance for deriving meaningful water quality criteria for the control of intermittent pollution.

This paper describes the results of a study which has been carried out on Pendle Water, a river which flows through the urban catchment of Burnley, Lancashire, UK. Both the chemical and biological quality of Pendle Water are adversely affected by storm sewage discharges during heavy rainfall events. The ecological investigation has been primarily concerned with impact of these episodic discharges on benthic invertebrate communities and physiological responses in fish.

Quantitative sampling of macroinvertebrates has indicated that storm sewage discharges may have a significant impact on the structure and diversity of benthic communities in receiving waters. Physico-chemical properties of habitats appear to be altered in a way which tends to favour the proliferation of certain pollution-tolerant species and decrease the abundance of taxa intolerant of organic pollution. Insitu bioassays, including the WRc Mark III Fish Monitor, have been deployed to investigate physiological responses to storm events of different magnitude, duration and frequency. Results are discussed in relation to their application in the field validation of proposed water quality criteria for the control of intermittent pollution from combined sewer overflows.
Removal of Nutrient Salts in Relation with Algae in Ponds
Authors: Li Jianhua , Wang Jin , Zhang Jinlan
Published: May 2018

The quantity of algae and their dominant species and the quantity changes with month were investigated, and the changes in pH and increase in DO in Anda ponds resulting from photosynthesis were also discussed, which in turn promoted the evolution of ammonia nitrogen and the precipitation of phosphate. The relationship between chlorophyll within algal cells and the removal of nitrogen and phosphorous was studied,and the significant contribution of algae to the removal of ammonia nitrogen was further studied by static experiment. It was finally found that the removal of nitrogen is more effective than that of phosphorous in the ponds, with the removal efficiencies dependent on time and condition due to the excess in phosphorous. Removal efficiencies for nutrient salts in Anda municipal ponds system were as follows: 60–99.3% for ammonia nitrogen, 20.5–72.6%for TN, 22.6–1.4% for phosphate and 20.1–48.1% for TP.
Elements of Management Systems in Coastal Regions
Authors: Abbott M. B. , Jensen Ole Krull , Warren I. R.
Published: May 2018

The progress made in numerical modelling of coastal regions now allows the elaboration of more complete and realistic management systems for these regions. Such systems must however take cognisance not only of chemical and biological processes, but also of legislative and other social constraints. The feasibility of such systems is now being actively investigated. It has been found that one promising approach to management systems is to design them as Aquatic Environment Management Systems (AEMS) that will, in the first instance, drive advice servers. A specification for a complete AEMS is presented and this is augmented by functional specifications of its five principal components.
Optimization of the Operation of the Oxidation Ditch Process Incorporating a Dynamic Model
Authors: von Sperling M. , Lumbers J. P.
Published: May 2018

A procedure for the optimal management of the oxidation ditch process was developed, comprising the integration of a dynamic process model, an input forecaster and an optimization algorithm. The system can be set to optimize operating costs (having the effluent quality as constraint) or process performance (having a maximum budget as constraint). Simulations with data from full scale oxidation ditches showed the usefulness of the method in terms of on-line control and/or off-line planning. A comparison between the proposed strategy and other conventional control policies was done by Monte Carlo simulation, varying the values of the inputs and initial states. Statistical analysis of the results indicated that, in general, the optimal management was able to give a significantly better effluent quality but, in some cases, at higher operating costs.
State and Coefficients Estimation for the Activated Sludge Process Using a Modified Kalman Filter Algorithm
Authors: Ayesa E. , Florez J. , García-Heras J. L. , Larrea L.
Published: May 2018

An advanced identification algorithm is proposed for the on-line estimation of the non-measurable state variables and coefficients of the IAWPRC biodegradation dynamic model for the Activated Sludge process. The new algorithm employs real-time measurable data. This paper represents a first step in a mathematical methodology which intends to improve the present techniques used for model calibration and validation. The algorithm is based on a recursive non-linear extended Kaiman filter and it has been verifiedrby using simulated values of the measurable data. These simulations describe the behaviour of a specific physical configuration of the AS process under steady and transient operational conditions. When the coefficients are assumed to be known, the algorithm estimates the state rapidly and accurately even when the measurements are affected by a very high degree of noise and the initial estimates are very far from the real values. The speed of convergence of the algorithm decreases when neither the states nor the coefficients of the model are known.
Operational Water Quality Management: Transient Events and Seasonal Variability
Authors: Beck M. B. , Adeloye A. J. , Finney B. A. , Lessard P.
Published: May 2018

The practical urgency of addressing problems of the transient pollution of receiving waters by stormwater overflows has done much to assist in dismantling the restrictive assumption of a steady state that has until recently dominated analyses of water quality management. Despite this, however, there are still misconceptions about the complexity and data requirements of dynamic mathematical models, and about the capacity to exercise operational control over the hour-by-hour, day-by-day performance of a wastewater treatment plant. The paper reviews some of these misconceptions, and draws attention to the crucial need for servicing the development of models of transient behaviour with appropriately designed, specialised, monitoring exercises. Results from a case study based on the River Cam in eastern England are presented. These illustrate the impacts of stormwater discharges on the receiving water body as a function of various treatment plant designs and operational strategies. Results are also presented for a second case study, based on the Bedford Ouse River in eastern England. A dynamic model of receiving water quality has been used for assessing the scope for seasonally varying policies for the treatment of ammonium, subject to fish toxicity and in-plant oxygenation requirements. Further studies exploring the interactions between seasonally varying conditions and transient pollution events are currently in progress.
Computerized Biological Treatment Operational Process Control
Authors: Stover Enos L. , Campana Christopher K.
Published: May 2018

An integrated data management and operational process control system has been developed to assist in operations of biological wastewater treatment plants. Bio-kinetic process control equations provide daily operational strategies based on moving analysis of plant performance. Statistical analysis of trends and simulation add additional analytical power to the package. Diagnostic and predictive Expert System capabilities are also being developed to assist in plant operations.
Study of Flocculation Mechanisms by Observing Effects of a Complexing Agent on Activated Sludge Properties
Authors: Eriksson L. , Alm B.
Published: May 2018

Electrostatic interactions between bacterial surfaces, extracellular polymers (ECP) and polyvalent metal ions are important in activated sludge flocculation. An indirect study of these mechanisms was done by adding different concentrations of EDTA to activated sludge samples from 6 Swedish wastewater treatment plants. The effects on sludge properties were studied with sedimentation and filtration tests as well as analysis of released extracellular polymers.

EDTA had a significant effect on sedimentation velocity in all investigated sludges. This shows that charged polymers are important for the properties of the floc surfaces and in building up the sludge macroflocs. The effect on filtration resistance where the bulk properties of the primary flocs are more important varied considerably for the different sludges. Thus, both electrostatic and other interactions are involved to a varying extent in building up the primary flocs in the sludges investigated. Variations in sedimentation velocity, residual turbidity, filtration resistance and release of ECP with variations in EDTA concentrations could be explained by effects of polyvalent metal ions on ECP binding and conformation.
Continuous Estimation of Short Term Oxygen Demand from Respiration Measurements
Authors: Spanjers H. , Klapwijk A.
Published: May 2018

The short Term Oxygen Demand /STOD/ is a valuable parameter for monitoring the influent wastewater and is partieulary important in control of activated sludge processes. In this paper, a method for the continuous estimation of the STOD is described. The method is based on the measurement of three different oxygen uptake rates of the activated sludge: endogenous respiration rate, momentary respiration rate and actual respiration rate. Measurement of the latter needs special experimental conditions. The respirometer used is a Wazu respiration meter which is capable of continuous and on-line measuring the oxygen uptake rate.

The method was applied to a completely mixed continuous-flow pilot plant which was fed with domestic wastewater. The results show a varying STOD with significant peaks at about noon, indicating higher concentrations of readily biodegradable compounds. The STOD of the examined wastewater appears to be mainly caused by ammonia being oxidized by nitrifiers.
Swedish Full-Scale Experiments on Modified Operational Modes in Removal of Nutrients
Authors: Eklund L. , Hellström B. G. , Hultman B. , Lind J. E. , Nordström B.
Published: May 2018

During the first part of the 1970s, large amounts of money were invested in Sweden in new plants for biological-chemical treatment and in complementary treatment steps at existing plants for municipal wastewater treatment. The post-precipitation process constituted the normal process combination, with the activated sludge process as the most common biological treatment process. Practical experiences over the last ten years have shown that post-precipitation plants can be operated in several operational modes, such as two-stage precipitation with different precipitation agents, different methods for recirculation of sludges, nitrification and denitrification, and biological phosphorus reduction. This development is due to more stringent effluent requirements and a desire to achieve lower costs and lower energy and chemical consumptions.
Comparative Studies on Water and Wastewater Treatment by Reverse Osmosis
Authors: Bilyk A. , Szpadt R.
Published: May 2018

The process of water and wastewater desalination by reverse osmosis in a full scale system was investigated. The system was the terminal part of a reclamation plant, in which water is recovered from tanning effluent. Permeate volume flux and pressure are related to the temperature of water and wastewater; volume flux is related to pressure; pressure and retention of dissolved solids are related to dissolved solids concentration in the feed. The membranes after two years of operation showed a relatively low ability of retaining dissolved solids (especially monovalent ions) which ranged from 65% to 79% for Cl−. The retention value, much lower than anticipated (95 %), indicates that there is progressive aging of the membranes and hydrolysis of cellulose acetate.
Factors Affecting the Design and Performance of Upflow Anaerobic Filters
Authors: Young James C.
Published: May 2018

Anaerobic filters have been used for almost twenty years to treat a variety of industrial wastes, yet until recently little was known about the factors affecting their design and performance. Tests with laboratory and full-scale plants operated under a variety of conditions have identified hydraulic retention time as the most important design and performance parameter. Influent waste strength and reactor height have essentially no effect on treatment efficiency when operating at a given hydraulic retention time. Media specific surface area and the orientation of the media seem to have a minor effect on performance but the benefit generally is not sufficient to justify increasing the specific surface area beyond about 100 m2/m3. Effluent recycle provides only a small improvement in treatment efficiency but may be beneficial to reduce the need for adding chemicals for pH control. A performance model is presented that can be used for obtaining approximate reactor sizes.
Start-Up, Operation, Monitoring and Control of High-Rate Anaerobic Treatment Systems
Authors: Hickey R. F. , Wu W.-M. , Veiga M. C. , Jones R.
Published: May 2018

High-rate anaerobic treatment has emerged as a viable alternative for the treatment of many industrial and municipal wastewaters. A number of different process options have been reduced to practice, although some configurations are clearly more well developed than others. One common thread that links these various processes (principally the Anaerobic Filter, Upflow Anaerobic Sludge Blanket and Expanded/Fluidized Bed Reactors), is the ability to effectively separate solids and hydraulic retention times. This permits design to be based upon the degradative capacity of the anaerobes, not growth rate and results in reduction of treatment times from days (typical for conventional digester systems) to hours.

This article compares and contrasts the principles of start-up and operation of these different high-rate anaerobic systems based upon laboratory research and full-scale operating experience gained over the past two decades.

The application of anaerobic processes for treatment of certain toxic and hazardous waste streams is just beginning. The limited work performed to date and anticipated future needs for process monitoring and control are also presented in this article.
Public Health Concerns in Wastewater Reuse
Authors: Cooper Robert C.
Published: May 2018

There is a growing need to reuse wastewater not only to reduce waste discharges to surface waters but also as an important water resource. The potential for increased risk of infectious disease to communities using reclaimed water continues to be a concern. With the growing interest in the use of recycled water for groundwater recharge and directly as a potable supply adjunct there is an increased awareness of chemical quality with emphasis on trace organic compounds. With proper attention to water quality standards and reclamation plant reliability high-quality water can be produced which should not pose an increased risk of disease to those using the water.
Quality Criteria for Reclaimed Water
Authors: Crook James
Published: May 2018

The applicability of reclaimed water for any particular use depends on its physical, chemical, and microbiological quality. The effects of physical and chemical parameters for nonpotable uses of reclaimed water are, for the most part, well understood and criteria have been established. Health-related microbiological limits are more difficult to quantify, as evidenced by widely varying standards and guidelines throughout the world. This paper presents existing reclaimed water quality limits for various uses, and compares the California Wastewater Reclamation Criteria, which are typical of health-related standards in industrialized countries, to WHO guidelines, which are directed principally at developing countries. The California regulations are considerably more restrictive than the WHO guidelines. Because of unknowns concerning the presence, identification, concentration, and health significance of many chemical constituents that may be in reclaimed water, quality criteria for potable reuse are not well developed and are not addressed in this paper.
Guidelines for Environmental Enhancement in Japan
Authors: Takahashi Masahiro
Published: May 2018

New guidelines of water reuse for environmental enhancement have been established in Japan. There are two categories in the guidelines. One is aesthetical setting without public access, the other is limited contact use including shoreline usage, boating and fishing. We do not consider direct contact use such as swimming and bathing.

Two groups of guidelines were set. One group comprised basic guidelines which are not site specific, based on public health and visual appeal. We call these “Basic Guidelines”. The numerical guidelines for total coliform, BOD, SS, turbidity, and color unit are determined in the Basic Guidelines.

On the other hand, hydraulic and biological characteristics of environment enhancement differ according to the site, purposes, climate and so on. Consideration of the characteristic of each site should be paid carefully. We call such considerations as “Guidelines Depending on Type of Use”. The site-specific water quality index such as T-P, T-N, foaming substances are discussed here.
Anaerobic/Aerobic Pretreatment of Sugarcane Mill Wastewater for Application of Drip Irrigation
Authors: Yang P. Y. , Chang L. J. , Whalen S. A.
Published: May 2018

Because of inappropriate management of sugarcane mill wastewater in Hawaii, odor problems and handicaps to wastewater reuse for drip irrigation and sugarcane washing have developed. Based on the previous work on wastewater characterization and relevant literature review, a combined anaerobic (UASB) and aerobic (EAFB) treatment of supernatant of settled sugarcane mill wastewater for the application of drip irrigation was proposed and investigated. It has been found that the system can efficiently (≥ 99%) remove the organics and solids in wastewater within two days of hydraulic retention time provided. The treated effluent provides better water quality for application of drip irrigation. The alternatives (UASB + EAFB and UASB + AL) were compared based on the net present worth (NPW). It has been found that the combined treatment alternative (UASB + EAFB) for the application of drip irrigation is more cost effective than the alternative of (UASB + AL). Thus, combined (UASB + EAFB) treatment for sugarcane mill wastewater provides not only for the removal of pollution potential, but also for the reuse of the properly treated wastewater for drip irrigation in the land-limited and populated areas.
Sources and Fate of PCBs in the North Sea: A Review of Available Data
Authors: Klamer J. , Laane R. W. P. M. , Marquenie J. M.
Published: May 2018

From literature data it is calculated that on an annual basis, 11 to 17 tonnes of PCBs enter the North Sea. Largest sources are the Atlantic Ocean and the atmosphere: together they account for 60-79% of the total input. Sources with greatest impact are the rivers, sewers and sludge. Highest concentrations are found close to the Dutch shore and in the German Bight. The PCB levels result in adverse effects on the seal population in the Wadden Sea. Of the total world PCB production, at least 57% is still in use and their future dispersal into the oceans cannot easily be controlled. If the increase in ocean PCB concentration continues, it may ultimately result in the extinction of fish-eating marine mammals.
Phthalate Esters and Other Industrial Organic Chemicals in the North and Irish Seas
Authors: Law R. J. , Fileman T. W. , Matthiessen P.
Published: May 2018

Concentrations of a range of industrial organic chemicals (xylene, styrene, chlorobenzene and five phthalate esters) have been determined in surface waters near the Humber, Mersey, Tamar, Tees and Tyne estuaries. Analyses were conducted using GC/MS in the multiple ion detection mode. In general, the highest concentrations (in the ng to µg dm−3 range) for all determinands were found at sites within the estuaries.

Selected samples were also analysed by scanning GC/MS and other compounds tentatively identified. There was only minor overlap between the compounds found at each of the estuaries, presumably a reflection of the industrial activities in the area.

A preliminary ecotoxicological assessment was made of both datasets.
Cemeteries - A Potential Risk to Groundwater
Authors: Pacheco A. , Mendes J. M. B. , Martins T. , Hassuda S. , Kimmelmann A. A.
Published: May 2018

Cemeteries are a source of environmental impacts among which is featured the risk to groundwater contamination by microorganisms that proliferate during the process of decomposition of bodies. The main objective of this work was to monitor the bacteriological quality of the water from the water table in three cemeteries chosen in accordance with geological and hydrogeological criteria: Vila Formosa and Vila Nova Cachoeirinha, located in the city of São Paulo, and Areia Branca in the city of Santos. These cities are situated in the state of São Paulo, Brazil. A total of 67 samples were collected through 36 piezometers installed in the internal area of the above-mentioned cemeteries, and were analysed between January and December of 1989. For this study microorganisms of fecal contamination were chosen, one pathogen, as well as two groups degradation of organic material bacteria.
The Use of Soil-Gas Sampling in the Study of Groundwater Pollution by Volatile Solvents (VOC): The Example of the Porto Feliz (São Paulo, Brazil) Case
Authors: Hirata R. C. A. , Cleary R. W.
Published: May 2018

In 1983, a serious accident occurred in Porto Feliz, São Paulo, Brazil when the rupture of a storage tank released 400,000 litres of volatile organic solvents. A large portion of the underlying aquifer was contaminated including some deep wells and shallow hand-dug wells.

Soil-gas sampling was the technique used to evaluate the degree and extent of contamination. The method is based on the analysis of small quantities of soil vapors extracted at shallow depths. The origin of these vapors is the underlying contaminated groundwater and the vapor concentration distribution reflects the degree and extent of aquifer contamination. Other techniques were rejected since the physico-chemical characteristics of the pollutants did not allow their detection by traditional geophysical methods and the thick unsaturated zone and difficult geology would have resulted in exorbitant drilling costs for monitoring wells.

The use of soil-gas sampling allowed mapping of the pollution plume, defining its two-dimensional shape and location. Vapor analyses at different depths permitted the establishment of concentration gradients and an estimation of vertical vapor flow behavior in the unsaturated zone as well as surface losses by volatilization.

Water levels in existing wells made it possible to construct potentiometric surface maps, defining the groundwater flow pattern. Periodic groundwater quality monitoring furnished data for the evaluation of the plume migration velocity and the influence of rainfall on the increase of pollutant concentrations in the aquifer.

The groundwater pollutant concentrations obtained gave a good correlation between the two means.
Evaluation of Groundwater Potential Pollution Sources in the State of São Paulo, Brazil
Authors: Bastos C. R. A. , Otta H. , Poppe L. P. M. , Silva M. F. B. , Dantas M. G. F.
Published: May 2018

The objective of this work is to present the methodology used in the project “Vulnerability Mapping and Groundwater Pollution Risk in the State of São Paulo, Brazil”, implemented by the DAEE, CETESB and Institute of Geology, and intended to be a risk assessment procedure to evaluate the threat of groundwater quality deterioration using existing data. Such method is based on the interaction between the natural aquifer vulnerability and an imposed contaminant load generated by human activities, and aims to identify critical areas to prioritize the adoption of control measures and more intensive quality monitoring. This paper describes the principles used in the assessment of the contaminant load generated by industries, solid waste disposal and mining activities in the State. More than 500 industries were identified as important groundwater potential pollution sources, and a criterion of ranking their capability to generate contaminant loads to the aquifer was|established.
Delineation of Wellhead Protection Areas: Theory and Practice
Authors: Cleary Tereza C. B. F. , Cleary Robert W.
Published: May 2018

A preventive approach in groundwater protection programs throughout Europe and the United States, and almost unknown in Brazil, is to define the surface and subsurface areas, the Wellhead Protection Area (WHPA), from which a well or wellfield draws its water during a specified time. Overlaying a map of potential pollution sources on the delineated WHPA (Figure 1), those sources which fall within the WHPA boundaries are identified as definite threats, that need to be closely monitored, to the continued safe operation of the wellfield. Given the importance of effectively delineating the WHPA to protect public water supplies, the current delineation criteria, methods, and zones are presented, as well as analytical and numerical PC model analyses of different hydrogeological scenarios' effects on WHPA's size, shape and direction. Numerical models are shown to more accurately define WHPAs by taking into account the surrounding heterogeneous and anisotropic geology.
Numerical Modelling of the Fate of Residual Immiscible Fluids in Saturated Porous Media
Authors: Guiguer Nilson
Published: May 2018

In the subsurface, small but significant quantities of chemicals will be dissolved by groundwater in contact with Non-aqueous Phase Liquids (NAPL) and can result in groundwater contamination. The rate of NAPL dissolution will influence the magnitude of dissolved chemical concentrations in groundwater and the length of time that NAPL sources may cause groundwater contamination. A suitable understanding of NAPL fate in the subsoil is required in order to evaluate the sources of existing dissolved chemical plumes, to allow predictions of future plume migration and to evaluate the effectiveness of dissolved plume purging in situations where NAPL remains in the subsurface. In this study the mathematical formulation necessary to represent the behavior of NAPL in the saturated zone is presented. The results of the simulation of a trichloroethene spill demonstrates that immiscible liquids can act as a continuous contamination source in an aquifer for many decades, even in small quantities.
The Use of Fermentation Sludge as a Fertilizer in Agriculture
Authors: Larsen A. B. , Funch F. H. , Hamilton H. A.
Published: May 2018

Novo Nordisk is one of the world's largest producers of enzymes, insulin and biopharmaceuticals. This production is based mainly on biotechnology and fermentation processes. The waste from the fermentation process is non-toxic, but due to the high content of nitrogen and phosphorus the waste can cause eutrophication if it is discharged in the marine environment. Novo Nordisk has developed a process in which the fermentation sludge, which constitutes a large part of the waste, is used as an organic fertilizer - NOVOsludge - in agriculture.

The total amount of sludge is 500,000 m3/year, corresponding to 800,000 kg of nitrogen and 300,000 kg of phosphorus. Around 10,000 hectares of farmland benefit from this. Since a great proportion of the raw materials used in fermentation are based on agricultural products, this use is an example of re-cycling of nutrients.

Investigations of the uptake of the nutrients in different types of crops are made in order to develop still more efficient uses. The system which has been developed has also contributed to new rules for the utilization of organic waste material.
Waste Minimization: A Major Concern of the Chemical Industry
Authors: Gujer U.
Published: May 2018

Supplying the growing demands of society for goods and services is leading to a depletion of resources and an increase in the amount of waste generated. The uniqueness of the chemical industry requires special solutions. Waste management and waste minimization, including recycling, reuse, and valorization, must become integral parts of any production process or facility. Examples are given at the single process level, at the product group level, and at the production facility level of successful programs that eliminated or signifantly reduced the amount of waste generated.
Groundwater Use and Protection in the Petrochemical Complex Region, Camaçari, Bahia, Brazil
Authors: Rebouças A. C.
Published: May 2018

The Petrochemical Complex Region (COPEC) is located on the top of a huge aquifer (10,000 km2, with average thickness of 600m), chiefly composed of undifferentiated deposits of coarse to fine sands and gravels with lenses of interbedded silts and clays. This paper provides an overview of the problems, and proposes the data and organization requirements for developing a local groundwater protection program. The freshwater reserves (120 billion m3 and global groundwater flow to rivers of 3 billion m3/yr) may be considered a resource of unusually high value. The issue of contamination with Synthetic Organic Chemicals (SOCs) and toxic metals was first raised during the mid 1980s. This poses significant water quality problems and imposes special restrictions on the industrial development in this area, mostly because few high-quality alternative sources of drinking water remain in proximity to a human population of 3.5 million people. The policy of neglect cannot be continued without grave threats to human health.
A New Methodology to Obtain a Reduction of the Heavy Metal Concentration in Waste Originated in Solid Residues, “Chorume”
Authors: d'Avila J. S. , Matos C. M. , Cavalcanti M. R. , Andrade J. , Marques J.
Published: May 2018

The reduction of the heavy metals concentration in liquid effluents is difficult and the existing methods available are expensive and their efficiencies ate in general low. The normal procedure adopted is based on the recirculation of the “chorume”, sometimes with a high content of heavy metals, into the liquid effluent flux of the central processing unit having in general a biological treatment. Depending on the heavy metal concentration the efficiency of the biological process decreases, or in certain cases, collapses completely. Activated peat by using the acid process or the one developed by the Universidade Federal de Sergipe and Instituto de Tecnologia e Pesquisas de Sergipe becomes an excellent heavy metals sorbent, which in certain analytical conditions has a very high efficiency. The overall process is controlled by diffusion and is governed by a first order kinetics. The use of activated peat shows in several situations that this process is a feasible alternative to getting the reduction of heavy metals concentrations in simulated effluents with one or more cations. Preliminary results show a significant matrix influence. The organic matter presence in the effluent may alter the sorption efficiency depending on its composition. The optimum analytical condition varies with the effluent quality and promotes the highest efficiency in the reduction of heavy metals concentrations.
Landfarming of Drilling Wastes
Authors: Prantera M. T. , Mauro C. A. , Marins M. D. M.
Published: May 2018

Use of the soil as a receptor in the biodegradation of oily wastes is a widespread practice in the petroleum industry. Generated during drilling, these oily wastes may have intrinsic properties that inhibit microbial soil activity. CENPES, the Petrobrás research centre, has been studying disposal of these wastes. The results of physical and chemical analyses were used to select factors that may limit the application of these wastes in soil. High salinity and high baritine (BaSO4) contents, as well as substantial concentrations of some heavy metals, have been studied with the aim of ascertaining the maximum concentration of each at which degradation is still observed. Microbiological assays indicated maximum oil application rates varying from 1 to 20%, suggesting that each waste tested displays a different toxicity.
Evolving Issues on Development and Conservation of Lake Biwa – Yodo River Basin
Authors: Nakamura Masahisa , Akiyama Michio
Published: May 2018

Lake Biwa is situated in the uppermost reach of the Yodo River Basin and occupies one sixth of the prefectural territory of Shiga. In the downstream reach of the basin are such metropolises as Kyoto and Osaka, and the issues involving development and conservation of Lake Biwa have been extremely important for Shiga, Kyoto, Osaka and other suburban municipalities within the basin as well as in the neighbouring areas like Hyogo Prefecture. Throughout history, there were a number of upstream-downstream conflicts of interests. The Lake Biwa Comprehensive Development Plan, a plan involving development of a new water resource amounting to 40 m3/sec for Osaka and Hyogo, together with compensatory public work projects for Shiga, has been under implementation for almost 20 years and is about to be completed. The social and economic situations have changed over this period, and the actual demand for water has proven to be not as much as the prediction 20 years ago, based on which the plan was originally formulated. There had been claims against the Plan that a large-scale development plan involving lowering of the lake level by as much as 1.5 to 2.0m might cause irreversible damage to the lake. The paper reviews various issues evolved over years with respect to development and conservation of Lake Biwa - Yodo River Basin and the Comprehensive Development Plan.
Activated Sludge Process Response to Variable Inputs of Volatile Organic Contaminants
Authors: Melcer H. , Nutt S. G. , Monteith H.
Published: May 2018

Laboratory-scale activated sludge treatment systems were operated under dynamic loading conditions to investigate the non-steady state behaviour of volatile organic contaminants (VOCs) under controlled conditions. Four step tests were conducted in which an incremental increase in the concentrations of selected contaminants was applied to the reactor feed from background levels of about 15 µg/L to levels of about 100 µg/L for a duration of approximately three hydraulic retention times. Although it was not possible to define the relative contributions of stripping and biodegradation to the removal of the test VOCs, different mechanisms are responsible for the removal of short-term, non-steady state inputs of chlorinated and non-chlorinated VOCs. No apparent effect of SRT or HRT on VOC removal was observed at the conditions tested.
Stabilization of Hazardous Materials into Ferrites
Authors: Tamaura Y. , Tu P. Q. , Rojarayanont S. , Abe H.
Published: May 2018

Stabilization of the hazardous materials by the Fe3O4-coating method was studied. In the ferrite-formation reaction in the aqueous solution, the adsorption of the metal ions and the oxidation of the adsorbed Fe(II) ions are repeated on the surface of the ferrite particles. This reaction was adopted to the coating of the hazardous materials with the Fe3O4(or ferrite). By repeating the two steps of l)the addition of the Fe(II) aqueous solution into the suspension of the hazardous materials, and 2)the oxidation by passing air through the reaction suspension, with the Fe3O4 layer, we could coat the surfaces of the hazardous materials, such as the heavy metal sludge from the neutralization-precipitation process, the CaF2 precipitates in the treatment of the waste waters containing fluoride ion along with hazardous metal ions, and the soils containing Cd(II) ion. These Fe3O4-coated hazardous materials are very stable and no heavy metal ions are leached under the normal environmental conditions. The ferrite sludges formed in the “Ferrite Process” were highly stabilized by the present method, and by the heat-treatment.
Ageing Effects of Highmolecular Weight Organic Acids Which can be Isolated from Landfill Leachates
Authors: Frimmel F. H. , Weis M.
Published: May 2018

The huge number of landfills and the resulting seepage water leads to a negative influence on the ground water quality. Organic acids were isolated over a period of three years from anaerobic and aerobic leachate water and from model aquifers which were fed by the leachates. The amount of isolated DOC increased from the anaerobic samples to the aerobic ones. The characterization of the isolated acids clearly reflects an increase of the molecular weight and of the functional group content with increasing age of the landfill, and in the process of aerobic digestion. The results are not only of interest for a detailed understanding of the fate of organic material from landfill leachates and of the transport of pollutants in the groundwater, but represent a man-made influence on the genesis of humic substances.
Trends in Water Pollution Control in the Finnish Pulp and Paper Industry
Authors: Junna J. , Ruonala S.
Published: May 2018

The present situation of water pollution control in Finland is briefly described and some future trends are discussed. Discharge permissions settled by the authorities have recently been made to include also total phosphorus and chemical oxygen demand (CODC r) in addition to the conventional water pollution control parameters (suspended solids and biological oxygen demand; BOD7). In the near future, requirements for chlorinated organic compounds (AOX) are also to be expected. In the reducing of chlorinated organic compounds, the development of cooking and bleaching processes will probably have the major role. However, also external methods can be developed and improved in this respect. In reducing nutrient loadings, developing the external purification methods will probably be the most acute way.
Anaerobic Toxicity of Fines in Chemi-Thermomechanical Pulp Wastewaters: A Batch Assay-Reactor Study Comparison
Authors: Richardson D. A. , Andras E. , Kennedy K. J.
Published: May 2018

Toxicity of chemi-thermomechanical pulping (CTMP) wastewaters was tested in batch assays and in anaerobic sludge blanket reactors. In batch serum bottle tests particulate constituents were responsible for 80-90% of the inhibition of acetoclastic activity, and the soluble (fines-free) fraction accounted for 10-20%. Performance of two 2-stage anaerobic sludge blanket reactor systems was compared, one receiving fines-free (NF) and the other unaltered (F) CTMP waste for 140 days. Both reactors became acclimatized to CTMP and developed a tolerance to resin acid concentrations as high as 300-1500 mg·1−1 in the sludge bed. The fines-free reactor was superior throughout, but the differences in performance did not reflect the batch test results. At the organic loading rate of 17-22 g soluble COD.g VSS−1·d−1 NF treated 100% CTMP waste with 42% and F with 38% removal efficiency. Fines accumulation in the sludge bed of F reactor caused a 70% increase in bed volume, resulted in deterioration of sludge settleability, and led to an increased likelihood of biomass loss.
Biodegradability of Chlorinated Organic Compounds in Pulp Bleaching Effluents
Authors: Häggblom Max , Salkinoja-Salonen Mirja
Published: May 2018

In this work the biodegradability of displacement bleaching effluents of kraft pulping was studied. A sequential treatment with an anaerobic fluidized bed and an aerobic trickling filter was effective in degrading the chlorinated high- and low-molecular-weight material. The treatment significantly reduced the COD, BOD and the organic chlorine (AOX) of the wastewater. COD and BOD reduction was greatest in the aerobic process whereas dechlorination was significant in the anaerobic process. Less than 3% of the COD removed was generated to sludge. With the combined aerobic and anaerobic treatment over 65% reduction of AOX and over 75% reduction of chlorinated phenolic compounds was observed. The COD/AOX-ratio of the wastewater was similar before and after treatment, indicating that the chlorinated material was as biodegradable as the nonchlorinated. Microbes capable of mineralizing pentachlorophenol constituted approximately 3% of the total heterotrophic microbial population in the aerobic trickling filter. Two aerobic polychlorophenol degrading Rhodococcus strains were able to degrade polychlorinated phenols, guaiacols and syringols in the bleaching effluent.
The Onset of Lignin-Modifying Enzymes, Decrease of AOX and Color Removal by White-Rot Fungi Grown on Bleach Plant Effluents
Authors: Lankinen V. P. , Inkeröinen M. M. , Pellinen J. , Hatakka A. I.
Published: May 2018

Decrease of adsorbable organic chlorine (AOX) is becoming the most important criterion for the efficiency of pulp mill effluent treatment in the 1990s. Two methods, designated MYCOR and MYCOPOR which utilize the white-rot fungus Phanerochaete chrysosporium have earlier been developed for the color removal of pulp mill effluents, but the processes have also a capacity to decrease the amount of chlorinated organic compounds. Lignin peroxidases (ligninases) produced by P. chrvsosporium may dechlorinate chlorinated phenols. In this work possibilities to use selected white-rot fungi in the treatment of E1-stage bleach plant effluent were studied. Phlebia radiata. Phanerochaete chrvsosporium and Merulius (Phlebia) tremellosus were compared in shake flasks for their ability to produce laccase, lignin peroxidase(s) and manganese-dependent peroxidase(s) and to remove color from a medium containing effluent. Softwood bleaching effluents were treated by carrier-immobilized P. radiata in 2 1 bioreactors and a 10 1 BiostatR -fermentor. Dechlorination was followed using Cl ion and AOX determinations. All fungi removed the color of the effluent. In P. radiata cultivations AOX decrease was ca. 4 mg l−1 in one day. Apparent lignin peroxidase activities as determined by veratryl alcohol oxidation method were negligible or zero in a medium with AOX content of ca. 60 mg l−1, prepared using about 20 % (v/v) of softwood effluent. However, the purification of extracellular enzymes implied that large amounts of lignin peroxidases were present in the medium and, after the purification, in active form. Enzyme proteins were separated using anion exchange chromatography, and they were further characterized by electrophoresis (SDS-PAGE) to reveal the kind of enzymes that were present during AOX decrease and color removal. The most characteristic lignin peroxidase isoenzymes in effluent media were LiP2 and LiP3.
Membrane Filtration Combined with Biological Treatment for Purification of Bleach Plant Effluents
Authors: Boman B. , Ek M. , Heyman W. , Frostell B.
Published: May 2018

A bleach plant effluent from softwood kraft pulping was treated in the laboratory with a combination of ultrafiltration and different biological methods. The E-stage effluent was firstly membrane filtered using membranes with a nominal cut-off of 8,000 Dalton. In the filtration, a concentration factor of 15 was used at 55°C. The treatment resulted in 89% AOX removal and 87% COD removal. Calculated in relation to the actual flows of E-stage and (C+D)-stage effluent at the mill, this corresponded to AOX and COD removals of 20% and 41% respectively. Before the biological treatment, the permeate was mixed with (C+D)-stage effluent and treated in three parallel biological systems, an aerated lagoon with and without solids recycle, an airlift system with a mixed fungal flora and an anaerobic filter. For the lagoon treatment, a hydraulic retention time of 7 days was used at biomass concentrations of 70, 350 and 480 mg TSS/l and 20-22°C. The fungal system was evaluated at retention times of 5.5 11 and 22 h, 770 mg TSS/l and 37°C. For the anaerobic filter, retention times of 1, 5 and 25 h at a temperature of 35°C were used.

Very promising results were obtained with the combination of physical and biological treatment. The aerated lagoon with solids recycle gave the best results with 66% of AOX, 72% of COD and 95% of the BOD being removed in the combined process. The anaerobic filter also gave good results, but in practice a small aerobic post-treatment would probably be necessary. The three systems were also evaluated for the removal of chlorinated phenolic compounds and acute toxicity according to the Microtox test. The results suggest that a combination of membrane filtration and anaerobic/aerobic or just aerobic treatment would be an attractive way to handle kraft mill bleach plant effluents.
Treatability of Bleached Kraft Pulp and Paper Mill Wastewaters in a New Zealand Aerated Lagoon Treatment System
Authors: Stuthridge T. R. , Campin D. N. , Langdon A. G. , Mackie K. L. , McFarlane P. N. , Wilkins A. L.
Published: May 2018

The effectiveness of the two biological treatment systems operating at a New Zealand bleached kraft softwood integrated pulp and paper mill was assessed. The two systems operate in different configurations. Treatment system A, which receives general mill wastewaters and chlorination stage bleaching discharges utilises deep, aerated lagoons and has a 4.5 day retention time. Treatment system B, which receives alkali extraction bleaching wastewaters and foul condensates, uses a lagoon system with a retention time of 45 days.

Detailed chemical analyses of the untreated and treated wastewaters were made. Mass balances were calculated for a range of physical parameters and for specific chlorinated and non-chlorinated organic constituents. Significant differences in the treatability of various constituents were found. In particular, while system A was able to reduce levels of AOX by 65%, no significant reduction in AOX occurred in system B. In contrast, system B reduced levels of chloroacetic acids by 84% while system A did not achieve any statistically significant removal of these compounds. The treatability of chlorophenolic compounds also differed. System A was unable to remove chlorophenols and chloroguaiacols while system B did not reduce levels of chlorocatechols.

These results confirm that the treatability of bleached kraft pulp and paper mill wastewater constituents is dependent upon the characteristics of the treatment systems and the compositions of the wastewaters.