bluuebunny/crossref_metadata_2025 huggingface dataset:
Operation Experiences with Biological Phosphorus Removal at the Sewage Treatment Plants of Berlin (West)
Authors: Peter A. , Sarfert F.
Published: May 2018

In investigations concerning sludge bulking in Berlin enhanced biological phosphorus removal was first observed unexpectedly. Because since 1986 an officially preset limit of 2 mg TP/l must be kept in all Berlin wastewater discharges it was decided to explore the capabilities of the observed mechanism under the specific circumstances of the exciting two large treatment plants in Ruhleben (240,000 m3/d) and Marienfelde (100,000 m3/d). For this purpose some of the existing units at both plants were equipped with anaerobic zones which were generated mainly by process modifications. Additionally stage one of the Ruhleben plant was altered completely in order to investigate the combination of biological phosphorus and nitrogen removal as a special pilot study in three parallel trains. The research activities and treatment results gained in each of the two stages of the Ruhleben and in the Marienfelde plant are reported in detail. For example BOD-related phosphorus removal rates were obtained ranging from 2.3-4.5 mg TP per 100 mg BOD removed. It must be stressed that all examinations were performed on full-scale conditions. At present the given limit of 2 mg TP/l in the Ruhleben plant is met without any chemical precipitation at least on average. From the beginning biological phosphorus removal will be integrated into further projected extensions.
Disposal of Wastewater from Flue Gas Desulphurization (FGD)
Authors: Gostomczyk M. A. , Grochulska-Segal E. M. , Sozański M. M.
Published: May 2018

Wet methods of FGD produce troublesome wastewater which, contains large amounts of suspended solids. The hot flue gas stream which is passed through the absorber gives an effluent which contains dissolved sulphur compounds. This effluent is sent to a special reactor for pH adjustment by lime treatment, as well as for the precipitation of calcium sulphites and calcium sulphates.

In this study special consideration was given to the following items: (1) sedimentation of particulate matter (suspended solids) produced during quasi-simulation of wet FGD and during pH adjustment of the sorption effluent by lime treatment, and (2) flow characteristics of sedimentation sludges.

In terms of particulate separation, the efficiency of the sedimentation process was far above 70%. The best gravitational thickening effects and the most efficient release of the sludge were achieved in vertical settling tanks with deep funnels of 60° bottom slope.

Depending on the water content, sedimentation sludges behave either as a Newtonian fluid or a Binghara plastic. This behaviour should be taken into account when pipe transport is considered.
The Start-Up, Operation and Monitoring of High-Rate Anaerobic Treatment Systems: Discusser's Report
Authors: Weiland P. , Rozzi A.
Published: May 2018

The reduction of the duration of start-up and the improvement of process control are important factors in order to increase the competitiveness of anaerobic high-rate reactor systems. This paper discusses and reviews the specific similarities and differences of UASB, filter and expanded/fluidized bed reactors with respect to start-up, operation, parameter monitoring and process control. The influence of microbial, biochemical and physical parameters upon reactor start-up and process performance is evaluated and methods for process monitoring and control are described. The different role of stability indicators, which give an early warning signal of oncoming unstable process conditions, and control variables, which must be kept constant during operation, is discussed with respect to process control and reactor start-up. The merits and weak points of each reactor system are presented and all systems are qualitatively compared.
Golf Course Irrigation with Reclaimed Wastewater
Authors: Mujeriego Rafael , Sala Lluis
Published: May 2018

Irrigation with treated municipal wastewater has been conducted at the Mas Nou Golf Course since September 1989, in the framework of a jointly sponsored demonstration project. The results obtained during the first 18 months have provided useful criteria for ensuring a satisfactory public health protection and adequate aesthetics of the golf course facilities. The established disinfection strategy together with the natural microbial inactivation taking place at the two landscape impoundments can provide an irrigation water with consistently less than 10 cfu/100 mL of faecal conforms and faecal streptococci. Sudden episodes of algae removal from suspension have been experienced in the first impoundment. However, no aesthetic deterioration or mosquito development has occurred in either of the two impoundments. Preliminary studies of the microbial content of aerosols have shown that by an adequate disinfection of the secondary effluent and the operation of the water jets only during low wind periods it is possible to prevent microbial dispersion by aerosols. The operation and maintenance cost of irrigation with reclaimed municipal wastewater is close to 56 ptas/m3, including pumping costs. An effort to improve the quality of water supply, by preventing the introduction of seawater or brackish water into the sewerage network, as well as improving efficiency and reliability of wastewater treatment processes and operation and management of irrigation systems will greatly contribute to expand the water resources available at many coastal resort towns in the Mediterranean.
Appropriate Wastewater Treatment and Reuse in Morocco – Boujad: A Case Study
Authors: Niedrum S. B. , Karioun A. , Mara D. D. , Mills S. W.
Published: May 2018

Reuse of wastewater for crop irrigation is essential to sustain agricultural growth in a country such as Morocco where water resources are scarce due to the hot, arid climate. However few towns in Morocco have sewage treatment facilities and reuse with untreated wastewater is therefore widespread, and the public health risks from excreta related disease high.

A suitable treatment system to provide safe water for irrigation is the use of waste stabilisation ponds, which provide an effluent high in microbiological quality and also high in fertilizer value due to the large amounts of algae which are normally discharged. It was therefore decided to implement an integrated waste stabilisation pond, effluent reuse system as a demonstration scheme of the advantages, both in terms of improved crop productivity and public health of the local community. The town of Boujad in Kouribga Province was selected as a suitable site and this paper describes the background to the development.
Fate and Effect of Detergent Chemicals in the Marine and Estuarine Environment
Authors: Stalmans M. , Matthijs E. , de Oude N. T.
Published: May 2018

Detergents are high-volume consumer products which are discharged directly into domestic sewage after their use. They are removed in the treatment of domestic sewage and via instream removal mechanisms in surface waters. Important removal mechanisms are biological degradation, adsorption to sediments, etc. The degree of removal mainly depends on the physico-chemical and environmental properties of the chemical and on the type of sewage treatment. The continuous removal processes, combined with the continuous discharge to surface waters via treated or untreated sewage effluents, results in the presence of detergent chemicals in surface waters, where they can further biodegrade. Detergent chemicals can thus, ultimately, enter the marine environment.

Data are presented on the discharged amounts of detergent ingredients, such as surfactants and phosphates, to surface waters and to the North Sea.

Furthermore, the fate and effects of a typical surfactant in the marine and estuarine environment are described. Monitoring data for one of the major anionic surfactants, Linear Alkylbenzene Sulphonate (LAS), are presented. A comparison of the measured concentrations of LAS with the concentrations, predicted on the basis of a measured dilution of the river water with sea water, shows that this surfactant continues to biodegrade under marine conditions.
Development and Applications of a Wellhead Protection Area Delineation Computer Program
Authors: Guiguer N. , Franz T.
Published: May 2018

In the last few years, groundwater management has concentrated on the protection of groundwater quality. An increasing number of countries has adopted policies to protect vital groundwater resources from deterioration by regulating human interaction with the subsurface, the use of potential contaminants, land use restrictions, and waste transport and storage.

One of the more common regulatory approaches to the protection of groundwater focuses on public water supplies to reduce the potential of human exposure to hazardous contaminants. Under the framework of the Safe Drinking Water Act amended by U.S. Congress in 1986, The U.S.EPA (1987) issued guidelines for the delineation of wellhead protection areas, recommending the use of analytical and numerical models for the identification of such areas.

In this study, the theoretical background for the development of one such numerical model is presented. Two real-world applications are discussed: in the first case history, the model is applied to a Superfund Site in Puerto Rico as a tool for assessment of the effectiveness of a proposed pump-and-treat scheme for aquifer remediation. Based on simulation results for the evolution of the existing contaminant plume it was verified that such a scheme would not work with the proposed purging wells. The second case history is the delineation of a wellhead protection area in the Town of Littleton, Massachusetts, and subsequent design of a monitoring well network.
Multivariate Analysis of a Coastal Phreatic Aquifer Using Hydrochemical and Isotopic Indicators, Buenos Aires, Argentina
Authors: Hernández M. A. , González N. , Levin M.
Published: May 2018

Hydrochemical and isotopic indicators were used to improve diagnosis in an area where the outcrops of the hydrogeological units were previously defined. Environmental isotopes (18 Oxygen, Deuterium and Tritium) have been applied while interpretation with both tools (Chlorides-18 Oxygen) was done as well.

The use of this kind of tracers allowed us to settle the hydrodynamic mechanisms, specially the recharge zones with nearly 10 TU values and how underground discharge occurs in lowlands, beach, Samborombon Bay and Samborombon River. Looking for a compatibility between hydrodynamics and hydrochemistry with those hydrogeological parameters, multivariate analysis was used. A matrix of 14 characters for 8 groups and 10 characters for 21 samples yielded correlation levels up to .98 and are shown through phenograms and principal components diagrams.
Waste Discharge Reduction Program Overview – Monsanto Agricultural Company
Authors: Keffer C. W.
Published: May 2018

Monsanto is committed to being a leader in reducing waste discharges to the environment. The Company announced in June 1988 a commitment to reduce air emissions of hazardous materials by 90% by the end of 1992. In addition, Monsanto Agricultural Company established a further goal to reduce the discharge of organic and hazardous inorganic materials to all environmental media. Projects have been identified for the Agricultural Company to achieve the 90% air emission reduction goal and to reduce projected 1995 waste discharges from 150 million pounds to 50 million pounds.
Process Development in Phenolic Wastewater Treatment
Authors: Teixeira A. C. , Balassiano G. L.
Published: May 2018

The limitation on the level of phenolic compounds in industrial waste water requires from Nitroclor the treatment of the mother liquors coming from its nitrophenols production unit, previous to sending them to biological treatment.

The literature and the accumulated experience during the last years show that nitrophenolic compounds removal at high temperatures is potentially dangerous due to the thermal instability characteristic of these products.

It was developed a new process minimizing the thermal risks and recovering nitrophenols with high purity.
Evaluation of Toxicity Test Procedure To Define Loading Rates in a Land Treatment System
Authors: Casarini D. C. P. , Cunha R. C. A. , Sato M. I. Z. , Sanchez P. S.
Published: May 2018

Land treatment is categorized as an option to treat hazardous organic waste in soils. This treatment relies on detoxification, degradation, and immobilization of hazardous wastes constituents within the defined treatment zone to ensure the protection of surface water, groundwater and soil.

The use of an appropriate battery of acute toxicity screening tests provides an acceptable method to estimate the initial application rates to be used in subsequent land treatment systems. This paper describes the Microtox acute toxicity test that has been developed and proposed by EPA - Environmental Protection Agency, to estimate the initial loading rates in a land treatment unit (EPA, 1986). The procedure involves conducting a sequence of Microtox tests on the water-soluble fraction of the soi], the waste, and selected waste-soil combinations. The results are used to establish a range of loading rates, which graphically are correlated with the EC50 or TU (toxic unit) to define the test loading rate which does not impact the biological activities of soil microorganisms.
Pilot-Scale Evaluation of Incinerating Listed Wastes from Specific Sources
Authors: Dempsey C. R. , Thurnau R. C.
Published: May 2018

Pilot-scale incineration testing was conducted at the United States Environmental Protection Agency's Incineration Research Facility to support the development of best demonstrated available technology standards for the treatment of several hazardous wastes from specific sources. This paper summarizes the results of this testing for four of these wastes. The objective was to determine if these four wastes could be incinerated by a well designed, well operated incinerator based on compliance with the hazardous waste incinerator regulations and to characterize the incineration residuals for hazardous constituents. It was found that these wastes could generally be incinerated in compliance with these regulations. However, the mist carryover from the air pollution control device would have to be more effectively controlled to meet the particulate standard for some of these wastes.
The Effect of Water Purification Ecological Engineering on the Cao Yang Round Creek
Authors: Chongxiao Wang , Jie Cai , Jiaxin Zhou , Sailan Xu , Yiping Yu , Zhixing Wang , Xiangming Xu
Published: May 2018

It nas been proved that planting various aquatic vascular plants with proper arrangements of time and space in tne eutropnic water of tne Cao Yang Round Creek nas formed an effective and stable ecological system for purifying water. Within two years, the water quality of the Round Creek has been improved significantly. The density of algae (content of chlorophyll a) has dropped by 95%, the total suspended solids is decreased by more tnan 90%, and COD is also reduced by 50%. The transparency of the water has increased from 15cm Before treatment to 53cm after treatment. Some parts of tne Creek are clear enough to see the bottom, to count tne fish. At the same time, beautification and planting of plants on the water surface has been carried our, together with the purification of the water. In this way, tne sightseeing value of water body is also increased.

The paper intends to probe an efficient way of harnessing the eutropnic water By practicing witn purification, Deautification and plant planting all at one time.
The Provincial Water Supply in Thailand and the Water Decade
Authors: Lowatanatrakul Wanchai
Published: May 2018

In order to comply with the International Drinking Water Supply and Sanitation Decade Plan (1981-1990), the Thai Government has set up a target that by the year 1990 not less than 95 percent of the Thai population, or more than 50 million persons, will be served with clean water, compared with 40 percent at the outset of the Decade.

However, in 1985, due to several constraints, the Provincial Waterworks Authority (PWA) revised its own target to cover only about 70% by the end of 1990. In 1988 it was estimated that about 2.883 million people in PWA's service areas or about 58.0 percent can be served by PWA's systems. If the number of population in service areas increases by 2.5% per year, PWA has to increase the number of connections at the rate of 12.62% per year for the remaining two years of the Decade in order to meet the 7 0% coverage target in 1990.

A budget of about 7,485 million baht (US $299 million) was allocated in FY 1980-89 for the expansion of water supply systems and services. It was estimated that the budget in 1990 should not be less than 1,950 million baht if the same target is to be accomplished. At any rate, there are still many constraints that could hamper the achievement, such as:–inadequate water resources, both in terms of quantity and quality due, to a great extent, to deforestation and pollution from factories and farming activities, etc.–inadequate manpower and equipment,–inadequate budget.–inadequate tariff, since the present tariff only covers operating expenditure but not future capital investments.
Microbial Degradation of Pentachlorophenol and Lindane in Laboratory-Scale Activated Sludge Reactors
Authors: Jacobsen B. N. , Nyholm N. , Pedersen B. M. , Poulsen O. , Østfeldt P.
Published: May 2018

The microbial degradation of pentachlorophenol (PCP) and lindane in the activated sludge process was studied. 14 steady-state experimental runs were performed in single-stage activated sludge reactors under various operating conditions. PCP and lindane mixed with three other model compounds were added to the feed as secondary substrate, with synthetic sewage as primary substrate. Reactor concentrations (dissolved) of the model compounds were in the range of 1-200 µg/l.

For PCP, the biodegradation increased with increasing solids retention time SRT. This indicates that degradation takes place by catabolic growth of a specific fraction of the biomass. At SRT > 8 days the 1st order biodegradation rate constant was about 2.5 × 10−3 1/(mg MLSS day) at a temperature of 15°C.

For lindane, the reverse relation was observed. Increased degradation was observed with increasing degradation of primary substrate. This indicates the presence of other mechanisms such as co-metabolism or probably reductive dechlorination.

In relation to upgrading of wastewater treatment plants to biological nutrient removal, xenobiotic compounds behaving like PCP are expected to be increasingly degraded. For compounds behaving like lindane, co-metabolic activity can be stimulated in plug-flow reactors rather than CSTR, and anaerobic zones in the activated sludge process may play an important role for the degradation.
Biological Treatment of a Landfill Leachate Containing Phenoxy Herbicides and Chlorophenols
Authors: McAllister P. J. , Rao Bhamidimarri S. M. , Chong R. , Manderson G. J.
Published: May 2018

A biological treatment process has been developed for a landfill leachate containing phenoxyacetic acid herbicides and their associated chlorophenols. The mixed microbial population (Pseudomonas sp.) enriched from soil was capable of mineral ising the key phenoxy components and has been found to be stable over 700 days in continuous culture, removing 99.5 % of phenoxies and 96.7 % of chlorophenols. Toxicity tests using D.magna and Microtox systems have shown a 90 % reduction in toxicity by biological treatment. A laboratory activated sludge system was developed resulting in complete degradation of the chlorophenols and phenoxies.
Preliminary Investigation on Acidification of Ground water in Finnish Wells
Authors: Korkka-Niemi Kirsti , Laikari Hannu
Published: May 2018

This research is based on information about approximately a hundred dug wells in five different areas in Finland. The fallout of sulphur compounds has determined the choice of the areas and the goal is to find out the degree of acidification of ground waters. The current situation has been compared to that 30 years ago as there was an investigation concerning the same wells at that time. The pH-value and degree of alkalinity of well water have systematically diminished in all the areas - most of all in areas of major sulphur compounds fallout. The observations and areas being few in number, no decisive conclusions should be drawn concerning the whole country.
Trends in Pollution Control in the Swedish Pulp and Paper Industry
Authors: Lagergren S. , Nystrom E.
Published: May 2018

Current production figures, control measures and discharges from the Swedish pulp and paper industry are described together with future trends and possibilities. The emphasis is on discharges of chlorinated organic substances and internal methods to control such discharges.
The Anaerobic Biodegradability and Methanogenic Toxicity of Pulping Wastewaters
Authors: Sierra-Alvarez R. , Kortekaas S. , van Eekert M. , Lettinga G.
Published: May 2018

The objective of this study was to evaluate the effect of various pulping conditions and different lignocellulosic feedstocks on the anaerobic treatability of pulping wastewaters. Wastewaters were prepared from lignocellulosic feedstocks commonly used in the forest industry, namely, pine, spruce and birch wood, and wheat straw. The pulping conditions used were representative of those applied in TMP and soda pulping processes.

The anaerobic biodegradability and the methanogenic toxicity of the various wastewaters were evaluated in standardized batch bioassays using anaerobic granular sludge. The acidification of the TMP wastewaters (conversion to CH4 and VFA) ranged from 68 to 87% of the total COD, indicating their high anaerobic biodegradability. TMP wastewaters were non-toxic to methane bacteria at concentrations expected in paper mill wastewaters. No inhibition was observed at 10 g COD/l. In contrast, wastewaters prepared in alkaline conditions were poorly biodegradable (approx. 50% acidification) and they caused severe inhibition of the methanogenic activity. The 50% inhibitory concentrations ranged from 2.1 to 5.4 g COD/l.

Additional experiments showed that wood resin components, poorly solubilized at acidic to neutral pH, but easily extractable in alkali, are responsible for most of the methanogenic toxicity observed in alkaline pulping wastewaters. These results indicated that contact of wood with alkali contributes significantly to increase the methanogenic toxicity of the pulping wastewater.
Treatment and Detoxification of Aqueous Spruce Bark Extracts by Aspergillus niger
Authors: Field J. A. , Lettinga G.
Published: May 2018

Debarking effluents of the forest industry are severely toxic waste streams due to their high tannin content. The objectives of this study were to evaluate the treatment and detoxification of debarking wastewater with tannin tolerant fungi. For this purpose, Aspergillus niger was cultivated on aqueous bark extracts and the toxicity was assayed utilizing methanogenic bacteria as the test organism. Sterilized aqueous extracts of spruce bark were diluted to 5.2 g COD L−1 (containing 2.7 g tannin COD L−1) in either citrate or tartrate buffer and inoculated with A. niger spores. During four day aerobic fermentations with citrate buffer, the elimination of unfiltered and soluble COD was 28 and 63%, respectively. The apparent yield of biomass averaged 34% of the extract COD; however, 12% of the extract COD was tannins adsorbed on the fungal biomass. The decrease in the tannin concentratio was 50%. According to gel chromatography results, the original oligomeric tannins that resisted biodegradation were those of the highest MW. The toxicity was consequently only partially reduced by the fermentation. During the tartrate buffered fermentations, the pH rose due to the metabolism of the organic acid in the buffer. The rise in pH beyond 6 promoted autoxidative reactions that caused extensive polymerization of the tannins which resisted biodegradation. This resulted not only in an enhanced elimination of the tannins but also in a complete detoxification of the extracts. Similar levels of detoxification could be obtained in sterile un-inoculated extracts by autoxidation alone (raising the pH and aerating the extracts). Likewise, extracts fermented in citrate buffer could be completely detoxified by a subsequent autoxidation treatment. The exclusion peak of the gel chromatograms (MW > 30,000 g mole−1) obtained from the highly autoxidized samples accounted for 53% of the UV absorbance, whereas no exclusion peak was present in the unoxidized extracts. For the biological treatment and detoxification of debarking wastewaters, we recommend the cultivation of tannin tolerant fungi followed by short autoxidation treatments that polymerize the oligomeric tannin fraction resisting biodegradation to non-toxic high molecular weight polymers.
Oxic Fluidized-Bed Treatment of Dichlorophenols
Authors: Puhakka J. A. , Melin E. , Järvinen K. , Tuhkanen T. , Shieh W. K.
Published: May 2018

Dichlorophenol (DCP) degradation was studied under oxic conditions using celite carrier material for immobilization of microorganisms in fluidized-bed reactors. Stoichiometric release of chloride and total organic carbon removal from 2,4-DCP and 2,6-DCP (20 mg/l as TOC) indicated complete mineralization at hydraulic retention times of 1 and 3 hours, respectively. GC/MS analyses showed no. DCPs or intermediary metabolites in the effluents. No 3,5-DCP degradation could be observed in the fluidized-bed reactor. Microorganisms were isolated from the reactor and their ability to degrade 2,4-DCP was evaluated in bioassays. 2,4-DCP degradation was slow by CPO III (gram-variable rod) and by CPO IV (gram-positive micrococcus) whereas the mixture of these isolates readily degraded 2,4-DCP.
Criteria for Nutrient-Balanced Operation of Activated Sludge Process
Authors: Grau Petr
Published: May 2018

Though N and/or P are most frequently the limiting nutrients in industrial applications of the activated sludge process, attention has to be given also to other potentially limiting nutrients, especially Fe, Mg and Mo. Two different mechanisms exist in nutrient-limited biomass; multiple limitation of the growth rate and single nutrient limitation of the biomass crop.

It is suggested that effluent concentrations of both NH3-N and NO−3-N are used as control parameters for nitrogen dosing adjustment. It is also suggested that dosing of both ammonia and nitrate to supplement nitrogen is considered for situations sensitive to total nitrogen discharge. The rationale for this is that excessive concentration of nitrate can be easily denitrified while excessive concentration of ammonia is not easy to remove in pulp and paper wastewaster treatment plant conditions.

Soluble orthophosphate is not an adequate control parameter for phosphate dosing since some of the phosphate precipitates can be utilized by microorganisms. Appropriate methods for assessing their availability to microorganisms in real situations are still missing.
Factors Affecting the Removal and Discharge of Organic Chlorine Compounds at Activated Sludge Treatment Plants
Authors: Saunamäki R. , Jokinen K. , Järvinen R. , Savolainen M.
Published: May 2018

Two extensive mill-scale tests were performed to find out to what extent and in what way organic chlorine compounds (AOX, chlorinated phenols) are reduced in an activated sludge process. In an extended aeration activated sludge plant the reduction of AOX was 40 - 50% and that of chlorinated phenols 70 - 80%. In a high-load activated sludge plant the corresponding removals were only 20 - 30% and 35 - 55%. The removal of oxygen-consuming substances was also lower in the high-load plant. It is evident that most of the chlorinated organics, especially low molar mass compounds, are removed by microbiological action. About 0.05 - 0.1 kg AOX per tonne of pulp was removed from the system with the excess biosludge, to be mixed with primary sludge and finally either burned in a bark-fired boiler or used as landfill. Some of the chlorinated compounds volatilized, but no quantitative estimate of the amount could be made. At the extended aeration activated sludge plant the AOX discharge to the recipient was only 1.3 kg/t when birch was the chief raw material. The corresponding figure at the high-load plant was 3.1 kg/t; this is partly because of the lower reduction and partly because 65% of the fibre raw material was softwood. A detailed study revealed differences in the micro-organisms present in the aeration sections of the plants. For example, there were practically no protozoa present in the high-load plant, and the number of species of bacteria was also smaller than in the low-load plant, where thermophilic bacteria and fungi were typically present. Tests carried out under controlled laboratory conditions showed that changes in conditions in the aeration section (temperature, pH or addition of a chemical) had little effect on the removal of AOX but a considerable effect on the removal of low molar mass compounds such as chlorinated phenols. An anaerobic/facultative lagoon before or after the activated sludge process did not improve the removals. Removing colloidal material from biologically treated effluent had a great influence on AOX.
Environmentally Desirable Approaches for Regulating Effluents from Pulp Mills
Authors: Sprague John B.
Published: May 2018

An overall strategy of regulation should always include three tactics: (1) discharge limits at the end of the effluent pipe, based on a reasonable level of industrial technology; (2) water-quality-based limits, strict enough to eliminate sublethal effects beyond a mixing zone; and (3) periodic ecological surveys to check the effectiveness of the first two approaches. Sets of increasingly restrictive “Levels of Achievement” should be formulated to provide steps for management. The final level should represent an ultimate goal of eliminating deleterious discharges, i.e. the effluent-free mill.

Recent Australian regulations for kraft mills give a balanced blend of all three tactics. Federal requirements in U.S.A. also have the three tactics, with good water-quality limits for sublethal toxicity, but a blind spot for organochlorines. Canadian federal regulations continue to focus only on tactic no. 1, with little acknowledgment of the receiving ecosystems, although some provinces add that. Both Sweden and Finland regulate by tactic no. 1, but from a background of site-specific knowledge and needs; relatively uniform sites in the Baltic for Swedish mills, and a diversity of freshwater locations for Finnish ones.
Capabilities of Biological Nitrogen Removal Processes from Wastewater
Authors: Henze M.
Published: May 2018

Biological denitrification of wastewater is a widespread technology for nitrogen removal from wastewater. Activated sludge technology is dominating over biofilm processes in practice. Recirculation and alternating processes are used to the same degree. The typical effluent quality that can be achieved on a long-term average is 4–10 mg/l of total nitrogen. Under certain circumstances effluent concentrations of 2–3 mg N/l can be obtained. Soluble organic nitrogen and nitrate are the dominating compounds in the effluent. Of these two, the soluble organic nitrogen content is difficult to control.
Denitrification with Biogas as External Carbon Source
Authors: Werner M. , Kayser R.
Published: May 2018

Denitrification with biogas consisting of approximately 60% methane was tested over one year in three types of lab-scale reactors. Denitrification of sanitary landfill leachate with biogas as a sole carbon source was found to be possible. Denitrification rates from 60 mg NO3–N/l. d with an activated sludge reactor, 150 mg NO3–N/l. d with a trickling filter and 550 mg NO3–N/l.d with a fluidized bed reactor were obtained. The oxygen concentration played a significant role in process optimization. Not only high concentrations of oxygen in the liquid medium but also low oxygen concentrations in the aeration gas inhibited denitrification.
The Effect of Surfactants on Nocardia Foaming in Activated Sludge
Authors: Ho Chu-Fei , Jenkins David
Published: May 2018

Biodegradation experiments of the non-ionic surfactants Igepal C-620 (an alkyl-phenol ethoxylate) and Neodol 25-7 (an alcohol ethoxylate) were performed, and biodegradation assessed by concentration, foam potential and surface tension measurements. Igepal C-62 0 biodegraded much slower than Neodol 25-7. The foaming of activated sludge was significantly enhanced by the presence of surfactants, but surfactants alone could not generate a stable foam if the sludge did not contain Nocardia cells. It was also found that products of surfactant biodegradation which were not detected by standard non-ionic surfactant analysis method (CTAS) might still possess some foam-enhancing ability. The results indicate that slowly biodegradable surfactants can enhance the foaming of Nocardia-containing sludge and increase the trapping of Nocardia foam in activated sludge plants.
The Roles of Intracellular Organic Storage Materials in the Selection of Microorganisms in Activated Sludge
Authors: Kohno T. , Yoshina K. , Satoh S.
Published: May 2018

The nature of organic energy reserves, and their relation to the microbial selection in activated sludge were of interest. The cellular carbohydrate and PHB were first examined in relation to their accumulation and degradation with activated sludge cultivated on glucose under batch and continuous feeding conditions. Then, CH accumulation was related with substrate uptake rate using activated sludge bearing different amounts of storage materials for both sludge. The cellular carbohydrate and PHB were of prime importance with both activated sludge. However, cellular carbohydrate was accumulated and decomposed more readily compared with PHB. The accumulation of cellular carbohydrate retarded its synthesis as well as glucose uptake. While no such relation was observed with PHB. The cellular carbohydrate accumulation capacity and attainable maximum specific substrate uptake rate were far greater for the batch-wise-fed activated sludge. Thus, the ability to accumulate cellular carbohydrate was found to be a prime selective advantage for floc formers in batch-wise-fed activated sludge. On the other hand, a sudden drastic stimulation of Sphaerotilusnatans in the continuously-fed activated sludge could not be well explained even though aided with Chudoba's kinetic selection theory.
Characterisation of Domestic Wastewater for Mathematical Modelling of the Activated Sludge Process
Authors: Sollfrank U. , Gujer W.
Published: May 2018

Based on oxygen uptake measurements a procedure is introduced to characterize organic material in domestic wastewater in view of mathematical models for the activated sludge process. The method allows the determination of stoichiometric as well as kinetic parameters necessary for the description of heterotrophic growth and hydrolysis of slowly degradable organic matter. From the information gained a kinetic model for the activated sludge process is formulated and experimentally verified under dynamic loading conditions.
Pilot-Scale Demonstration of Two-Phase Anaerobic Digestion of Activated Sludge
Authors: Ghosh Sam
Published: May 2018

An innovative pilot-scale two-phase anaerobic digestion process was developed to stabilize concentrated (7-5%) activated sludge at a 12-day SRT and a loading rate of 5 kg VS/m3 d. The pilot system exhibited an unusually high VS reduction of 73%, an aggregated carbohydrate-protein-lipid reduction of 71%, and a methane yield of 0.3 m3/kg VS added. Optimum acidogenic fermentation producing 9500 mg/l of organic acids was achieved at an HRT of 3 days and a loading rate of 16 kg VS/m3.d or higher. Enhanced acidogenic hydrolysis and prehydrolysis of polymerics and nocardial residues eliminated digester foaming. Sulfate and nitrate reductions, and syntrophic methane fermentation occurred during acidogenic conversions. Acetogenesis and aceticlastic methane fermentation were predominant in the methane digester, which generated 93% of the system methane production. Contrary to literature reports, there was no inhibition of acetogens or methanogens at a high ammonia-N concentration of 2500 mg/l and pH 7.7. The acid and methane digesters could be started quickly. They were resilient to temperature drops and loading fluctuations. Acid fermentation of 8% of the plant's WAS and addition of the resulting fermentation products (enzymes, organic acids, etc.) to the full-scale high-rate digester increased VS reduction by 46% and eliminated severe foaming. Full-scale two-phase digestion of WAS is scheduled to start in 1990.
Biofilm Properties and Simultaneous Nitrification and Denitrification in Aerobic Rotating Biological Contactors
Authors: Masuda S. , Watanabe Y. , Ishiguro M.
Published: May 2018

The properties of a blofllm developed on a Rotating Biological Contactor (RBC), such as the spaclal distribution of blofllm density, bacterial population and Intrinsic biochemical reaction rates, were measured. The blofllm density and the number of heterotrophs, nltrlflers and denltrlflers per unit volume of blofllm Increased with the blofllm depth. However, the intrinsic reaction rates per unit blomass did not significantly change with depth. Based on the above evidence, experiments on simultaneous nitrification and denitrificatlon were carried out using a covered RBC in which the oxygen pressure was controlled. The experimental results demonstrated that nitrogen removal efficiency in an aerobic RBC depends on the oxygen partial-pressure in the air phase, water temperature, hydraulic detention time and ratio of the influent concentration of organlcs to ammonia nitrogen.
Biodegradation Kinetics of Phenols in an Aerobic Biofilm at Low Concentrations
Authors: Arvin Erik , Jensen Bjørn K. , Torp Gundersen Anders
Published: May 2018

Aerobic biodegradation of the phenols: phenol, 2-methylphenol, 4-methylphenol, 2,4-dimethylphenol, 3,5-dimethylphenol and 2,4,6-trimethylphenol was studied in a biofilm reactor to establish kinetic constants under conditions where the phenols were the sole carbon sources. Phenol concentrations were very low, in the µg/l concentration range. 2,4,6-trimethylphenol was not degraded. The degradation of the other phenols was 1'st order at concentrations in the bulk phase below 20-50 µg/l. Zero order reaction seemed to govern the reaction above 200 µg/l. The l'st order rate constants are 3-30 times higher than the constants calculated for easily degradable organic compounds degraded at 100-1000 times higher concentrations (mg/l range). However, the maximum phenol utilization rates and the Monod constants were much lower compared with constants obtained for the microorganisms grown in the mg/l concentration range. The Monod constant was about 100 times lower. The removal of “total biodegradable phenol” (TB-phenol) was very similar to the removal of a specific compound. The degradation of TB-phenol was l'st order at concentrations below 200 µg/l. When the total biodegradable phenol degradation is near its maximum capacity (o'order reaction) there was a preferential degradation of the most easily degradable phenols, phenol and 2-methylphenol, leading to an apparent inhibition of the degradation of the more slowly degradable phenols, in particular 2,4-dimethylphenol and 3,5-dimethylphenol.
Anaerobic Treatment of a High-Strength Industrial Waste Bearing Inhibitory Concentrations of 1,1,1-Trichloroethane
Authors: Suidan M. T. , Wuellner A. M. , Boyer T. K.
Published: May 2018

A high-strength simulated industrial wastewater containing 5,900 mg/L of acetic acid, 3,000 mg/L of phenol, and 20-430 mg/L of 1,1,1-trichlorophenol (TCA) was successfully treated in an expanded-bed granular activated carbon (GAC) anaerobic reactor. Acetic acid and phenol removal efficiencies in this system were always better than 93 and 99 %, respectively, while TCA reduction was always better than 99.4 %. The adsorptive capacity of GAC was found to improve the performance efficiency of the system but was not necessary for the successful operation of the reactor. Acetate and phenol biodegradation was found to be inhibited by TCA, with a stronger effect observed on the methanogens. The treatment system was found to tolerate moderate fluctuations in the feed concentration of TCA.
Nitritification and Denitritification of High-Strength Ammonium and Nitrite Wastewater with Biofilm Reactors
Authors: Chen Sheng-Kun , Juaw Chin-Kun , Cheng Sheng-Shung
Published: May 2018

Two sets of fixed-film biological processes were operated separately for nitritification of amnonium and for denitritification of nitrite associated with organic compounds. High strength amnonium wastewater (50-1000 mg NH4+-N/l) could be effectively nitritified by a draft-tube fluidized bed which was operated at an extremely high loading of 1.0 kg NH4−1-N/m3.day with 95% amnonium conversion and 60 to 95% nitrite formation. Additionally, a biofilm fixed-bed was employed to denitritify the high strength nitrite (200 to 1000 mg NO2−-N/l) associated with organic compounds of glucose, acetate and benzoic acid. Complete nitrite removal could be achieved with sufficient HRT and COD/NO2−-N ratio. The conversion ratios were estimated experimentally at 2.5 for glucose and acetate, and 2.0 g ∆COD/g ∆NO2−-N for benzoic acid. A proposed process of an aerobic nitritifying biofilm reactor combined with an anoxic denitritifying biofilm reactor in series could be employed for complete nitrogen removal.
Biological Removal of Iron from Groundwater
Authors: Viswanathan M. N. , Boettcher B.
Published: May 2018

Host of the soluble iron in groundwater exists in complexes with organic matter. Removal of iron, complexed with organic matter, is difficult and requires the use of a strong oxidant such as ozone, chlorine, etc. This increases capital and operating costs of water treatment plants. Iron oxidizing bacteria like Gallionellaferruginea are known to oxidize iron and derive the energy for the reduction of CO2.

A biological reactor was developed, based on these principles, to remove iron from groundwater. The reactor was successful in reducing iron levels in groundwater from 2.5-3.0 mg/l to about 0.1 mg/l. It was observed that, apart from Gallionellaferruginea, Sphaerotilus spp. were also present in the reactor column. No major problems with respect to clogging of filters or the reactor column were experienced.
Performance Analysis of the Rotating Biological Contactor Process Based on Particle Fraction and Improvement of Final Effluent Quality
Authors: Tanaka Kazuhiro , Tada Minoru , Ito Mitsuo , Shimizu Noritugu
Published: May 2018

Biofilm processes are, in general, suitable for small-scale wastewater treatment plants. However, final effluent qualities of biofilm processes are not as good as those of activated sludge processes due to fine particles remaining in the effluents. To improve the effluent qualities of the Rotating Biological Contactors (RBC) process, the behavior of fine particles through the process and the removal of fine particles with solids-liquid separation methods, rapid filtration and coagulation-filtration, were investigated using the particle fraction method. The results are as follows:–An increase of the hydraulic retention time (HRT) in the RBC reactor reduced the amount of fine particles and increased the amount of coarse suspended solids of 44 µm or more in diameter, which are easily removed by clarification. Thus, the final effluent qualities were improved by the increase of HRT.–Suspended solids in effluent from the RBC process at the standard loading are so fine that improvement of the quality is not expected by only lowering the overflow rate of a final clarifier. In contrast, rapid filtration or a coagulation-filtration process is effective. The supended solid concentration and transparency of the effluent from the final clarifier was improved by a factor of two to four, and then BOD of the final effluent was removed by 40-85%.
Membrane Bioreactor on Domestic Wastewater Treatment Sludge Production and Modeling Approach
Authors: Chaize S. , Huyard A.
Published: May 2018

The membrane bioreactor, with an increase of biomass concentration in the aeration tank, permit work with low F/M ratio and a reduction in sludge production. The membrane bioreactor potentialities have been tested on a laboratory pilot for domestic wastewater treatment. Various operating conditions (HRT, SRT) were applied to investigate organic and nitrogen removal as well as sludge production.

Two modeling approaches were tested (maintenance phenomena, single sludge simulation process) with unsuccessfull predictions. Futher investigations are needed to better understand biological kinetics and phenomena in membrane bioreactor and to obtain higher flux on membrane processes.
Disinfection and Clarification of Treated Sewage by Advanced Microfiltration
Authors: Kolega M. , Grohmann G. S. , Chiew R. F. , Day A. W.
Published: May 2018

A study was conducted to investigate the use of an advanced membrane microfiltration system to disinfect and clarify secondary and primary treated sewage. The membrane microfiltration system tested incorporated a patented gas backwashing technique which significantly reduces fouling.

A comprehensive microbiological testing program established that all indicator bacteria and viruses were removed by this system. Testing for chemical quality showed significant reductions in BOD, suspended solids, turbidity, phosphorus, oil/grease and heavy metals.

Consistent filtration rates over several months were achieved without significant biological fouling. The study conclusively showed the capability of the microfiltration system to disinfect and clarify treated sewage.
Sewage Sludge Utilization Technology in Tokyo
Authors: Yasuda Yasuhiro
Published: May 2018

With increasing sewage sludge produced in Tokyo, it has become difficult to acquire land for sewage sludge disposal. To solve this problem, efforts have been made to develop sewage sludge utilization technologies. Five technologies have already been developed; conversion of sewage sludge to compost, conversion of sewage sludge to fuel, producing artificial lightweight aggregate from ashes, press burning of incineration ashes, and conversion of sewage sludge to melted slag. The present paper describes these utilization technologies.
Measurement of Operator Training Benefits
Authors: Kerri Kenneth D.
Published: May 2018

Benefits from operator training programs need to be measured to justify training budgets. Training benefits can be measured by both quantitative and qualitative procedures. Actual benefits from operator training programs are measured in terms of money saved on plant operation and maintenance, improved operator performance on certification examinations, better quality plant effluents, achievement of optimum chemical dose and favorable impressions on regulatory agency personnel. Benefits from training are also described on the basis of public satisfaction, public image, protection of capital investment, compliance with regulations, safety, staff selection and promotion and operator self-esteem.
The Effectiveness of Evapotranspiration Systems in Disposing of Wastewater in Remote Aboriginal Communities in Northwest Australia
Authors: McGrath D. R. , Ho G. E. , Mathew K.
Published: May 2018

The potential usage of Evapotranspiration (ET) systems in remote Aboriginal communities was investigated. ET system sizing requirements were determined from the water balance equation. Water loss from lysimeters planted with trees (Eucalyptus camaldulensis) or lawn grass and from bare soil and gravel was monitored over several months and compared to pan evaporation measured during the same period. It was found that ET from bare soil and grass followed similar trends to pan evaporation, ranging from 30-60% of pan evaporation for soil and from 60-80% of pan evaporation for grass. ET rates increased in the tanks planted with trees as the plants grew and exceeded pan evaporation rates. Evaporation from gravel-filled lysimeters was low, being as little as 10% of pan evaporation.