bluuebunny/crossref_metadata_2025 huggingface dataset:
Removal of Viruses by Microfiltration Membranes at Different Solution Environments
Authors: Herath Gemunu , Yamamoto Kazuo , Urase Taro
Published: May 2018

Rejection change by nuclepore microfiltration membranes with solution environment was investigated by using the RNA coliphages Qβ, MS2, fr and DNA coliphage T4. The obtained rejection results showed a higher rejection at lower pH than at higher pH for all viruses were obtained at pH closer to their isoelectric points and also the rejection variation indicates a similar pattern of behavior. This phenomenon of higher virus rejection at lower pH is explained with a possible viruses aggregation with each other due to their own electrostatic charge and isoelectric points. Also it was observed that the virus rejection was enhanced when they are in mixed environment. Finally the effect of protein was studied where, the virus rejection below pH 5.0 showed protein influence.
Agricultural Reuse of Wastewater and Global Water Management
Authors: Bahri A.
Published: May 2018

Agricultural reuse of wastewater has to be integrated into comprehensive land and water management plans taking into account water supply, wastewater collection, reclamation, and reuse. It may be incorporated, as a land treatment system, to the treatment cycle and considered as the nutrient recycling part of the loop. However, the water used for irrigation purposes has to meet the public health and agronomic quality requirements. Therefore, the treatment objectives and standards need to be clearly defined. This leads to reconsidering the treatment approach, the required treatment levels and processes, and the indicators that should be taken into account. A common approach to wastewater treatment and agricultural reuse has to be developed in order to define a reclaimed water quality that would be safe for each intended end use of the effluent, and acceptable in economic terms as well as the quality of the products coming from these wastewater reuse operations. Among the challenges that agricultural reuse operations have to overcome, planning and management are still major ones the require careful attention.
Membrane Treatment of Secondary Textile Effluents for Direct Reuse
Authors: Rozzi A. , Antonelli M. , Arcari M.
Published: May 2018

Post-treatment of secondary textile wastewater was tested at pilot scale on membrane modules (microfiltration MF, nanofiltration NF and reverse osmosis RO) for the direct reuse of polished effluent within the dyeing processes. The main polluting parameters monitored in the post-treatment were: organic compounds (COD), colour, surfactants and salinity (as conductivity).

The first treatment scheme was made of ceramic MF followed by NF. Aluminium polychloride was added at high concentrations (of the order of 70 mg Al/L) to avoid MF membrane fouling. The quality of the final permeate, produced by NF fed on the MF permeate, was acceptable for water reuse.

Clariflocculation (CF) plus multimedia filtration (MMF) followed by low-pressure RO was also tested. This process performed quite well: the RO module (p = 4 bar) ran for relatively long cycles (up to 80 hours) with 5% reduction of the permeate flow rate at a 10 L m−2 h−1 fluxes.

A techno-economical analysis on the experimental data indicate that a high quality effluent (COD < 10 mg/l; conductivity < 40 μS/cm; negligible residual colour), to be recycled in the textile dyeing industry, may be produced at affordable costs (less than 0.25 ECU) from secondary textile wastewater.
SBR Technology Used for Advanced Combined Municipal and Tannery Wastewater Treatment with High Receiving Water Standards
Authors: Banas J. , Plaza E. , Styka W. , Trela J.
Published: May 2018

The wastewater treatment plant (WWTP) in Nowy Targ, Poland, is the largest in Europe based on classical sequencing batch reactor (SBR) technology. The plant was completed in April 1995 as one of the essential elements in a program for the protection of the water quality in the Czorsztyn Reservoir. The process technology was designed for application to a typical municipal wastewater with a separate unit to treat tannery wastewater containing chromium. Experience from plant operation showed that the municipal wastewater inflow to the WWTP included tannery wastewater with increasing chromium concentrations, caused by poor wastewater management in the city. The average value in the influent was around 3 mg Cr/l (1996-1997) and showed an increasing trend. Investigations were focused on identification of the factors affecting the process performance. In this paper, evaluation of the treatment efficiency and process performance during 2 years of plant operation is presented, including studies of nitrification, denitrification and biological phosphorus removal. A cycle analysis was performed to investigate the reduction of different parameters during different phases of a cycle. Results of a sludge activity study based on OUR, AUR and NUR tests are presented and discussed.
Treatability of strong wastewaters from polyester manufacturing industry
Authors: Meriç S. , Kabdaşli I. , Tünay O. , Orhon D.
Published: May 2018

In this paper, the treatability of strong wastes originating from an organic chemicals industry was studied. Literature data were evaluated to assess the applicability of conventional and advanced methods of treatment to highly concentrated wastewaters. A detailed treatability study was conducted on the wastewater, which was provided from a small-scale polyester manufacturing plant. The manufacturing process involved only esterification reactions, generating a wastewater with a COD content of over 200,000 mgl−1. The applicable treatment methods to be tested were determined as biological treatment of activated sludge process with low organic loading and chemical oxidation with H2O2. Results of the biological treatability study indicated that 80% COD removal could be obtained with 10 days retention time, provided that the system was fed with a 1/100 diluted raw wastewater. Chemical oxidation of raw wastewater with H2O2 in acid conditions and using ferric chloride as catalyst yielded 70% COD removal. However, the dosage required to obtain this efficiency was about 1 kg H2O2 per m3 of wastewater. With these applications the wastewater was treated to yield a COD of lower than 2000 mg/l. Results of the study were discussed and evaluated considering complexity and cost of treatment.
Prediction of microbial toxicity of industrial organic chemicals
Authors: Trevizo C. , Nirmalakhandan N.
Published: May 2018

Aqueous solubility is evaluated as a predictor of microbial toxicity. Experimental toxicity data for activated sludge, methanogens, nitrobacter, and two commercial cultures, Polytox and Microtox were correlated with experimental solubility data for over 70 organic chemicals of diverse molecular structures and congeneric families. The database covered over 8 log units of aqueous solubility and over 6 log units of IC50 values. Statistically significant correlations were found between log (IC50) and log (solubility) for all the microorganisms, with coefficients of correlation ranging from 0.70 to 0.76 at a level of significance of p = 0.0001. An overall correlation was found to be log (IC50, mM/l) = 0.68 log (Solubility, mM/l) - 0.25, with an r2 = 0.756 for nearly 200 data points.
Performance of horizontal-flow anaerobic immobilized sludge (HAIS) reactor treating synthetic substrate subjected to decreasing COD to sulfate ratios
Authors: Cadavid Diana Loaiza , Zaiat Marcelo , Foresti Eugenio
Published: May 2018

The performance of a bench-scale horizontal-flow anaerobic immobilized sludge (HAIS) reactor treating a synthetic substrate under increasing influent sulfate (SO42-) concentrations was investigated. The synthetic substrate was composed of glucose, methanol and ammonium acetate, besides bicarbonate and trace metal nutritional solution. The reactor was filled with polyurethane foam cubic matrices for biomass immobilization. Influent chemical oxygen demand (COD) was kept almost constant along the experiments (2162 ± 250 mg.l−1) while influent sulfate concentration was increased from 9 to 501 mg.l−1, resulting in COD/SO42- ratio of 249, 66, 19.7 and 4.3 in the four experimental phases tested. After a short start-up period, no significant variations in COD removal efficiency were observed for the COD to sulfate ratios evaluated. Although sulfate reduction was expected to interfere with the methanogenic process, detrimental effects on the overall reactor performance were not observed. Moreover, monitoring parameters indicated that the reactor achieved stable operational conditions immediately after short transient periods following the increase of influent sulfate concentrations. Microscopic analysis of the sludge within the reactor permitted to observe the presence of both methanogenic and sulfate reducing bacteria, indicating that syntrophism and not competition seemed to be the predominant relationship between these two groups under the COD to sulfate ratios assayed.
Comparative study of wastewater purification efficiencies of two emergent helophytes: Typha latifolia and juncus subulatus under arid climate
Authors: Abissy M. , Mandi L.
Published: May 2018

The aim of the present study is to assess wastewater purification efficiency of two higher aquatic plant, Typha latifolia and Juncus subulatus in an arid climate.

The experiment was conducted from August 1994 to March 1996. The plots (capacity: 115 liters, diameter: 57 cm) were filled to 5 cm depth with gravel and 30 cm with soil (texture: 30% clay, 34% silt and 36% sand) and planted with young shoots of Typha and Juncus. The plots without plant were used as controls. The plots were weekly and exclusively irrigated by urban raw wastewater (25 liters). The influent was percolating through the substratum.

Results revealed significant performances for reduction of organic load in all systems. Indeed, COD and TSS removal efficiencies were respectively 91% and 73% for Typha latifolia, 92% and 76% for Juncus subulatus, 83% and 73% for an unplanted system. Depletion of nutrients during the experimental period was low and even negative: 32% TP (total phosphorus) and 31% NH4 (ammoniacal nitrogen) in Typha system, 27% TP and 17% NH4 in Juncus system, −10% TP and −22% NH4 in unplanted system.

In addition, the presence of these helophytes maintained sufficient porosity in order to allow water percolation treatment. The unplanted system clogged in winter.
Toxicity assessment of industrial wastewater by microbial testing method
Authors: Chen Chiu-Yang , Chen Jun-Nen , Chen Shing-Der
Published: May 2018

In this study the commercial Microtox® test is used to assess the individual response of existing wastewater pretreatment facilities in several high-intensive pollution industries. To control the discharge sources to the wastewater treatment facilities (WWTP), public WWTP with high-intensive pollution industries in three industrial districts are evaluated with their influents to determine the primary contributor of toxicants. From the tested toxicity results, the relationship between organic loads and toxic discharges exhibits a positive conjunction in the high-intensive pollution industries. If these industries can enhance their operating performance in the pretreatment system, the toxicity of their discharges can be effectively reduced.
Treatment of palm oil mill effluent (POME) with the membrane anaerobic system (MAS)
Authors: Fakhru'l-Razi A. , Noor M. J. M. M.
Published: May 2018

One of the major difficulties in anaerobic wastewater treatment processes is the need to retain a sufficient quantity of active biomass in the anaerobic reactor. The use of membranes to achieve external solid/liquid phase separation will result in the retention of the biomass at the surface of the membranes. In this study, the Membrane Anaerobic System (MAS) was used to treat industrial wastewater from a palm oil mill. The MAS was subjected to increasing organic loading rates (OLR) and a total of six steady states were attained. The first steady state influent COD concentration was 39,910 mg/l increasing to the final or sixth steady state COD concentration of 68,310 mg/l. The efficiency of COD removal was between 91.7 to 94.2 percent with an average HRT of 3.03 days. The maximum OLR applied during the sixth steady state was 21.7 kgCOD/m3/d. The reactor mixed liquor suspended solids (MLSS) was between 50,000 to 57,000 mg/l while the percentage of the mixed liquor volatile suspended solids (MLVSS) was between 74 to 82 percent. A crossflow ultraftration (UF) module was used to filter the final effluent and simultaneously retain biomass in the anaerobic reactor. A clear final effluent was produced but membrane flux rate deterioration was observed due to membrane fouling. Membrane fouling could be minimised with faster crossflow feed velocities and regular membrane flushing.
Analysis of reactive dyes using high performance capillary electrophoresis
Authors: Hansa A. , Pillay V. L. , Buckley C. A.
Published: May 2018

Increasing reports of coloured effluent from waste water treatment plants receiving reactive dye waste from textile mills indicate the need to learn more about the fate of these dyes. The project concerns the development of analytical techniques for the analysis of reactive dyes in textile waste. An analytical procedure using High Performance Capillary Electrophoresis (HPCE) and High Performance Liquid Chromatography (HPLC) for the separation of a range of reactive dyes in textile waste water is described. The dyes belong to a range of bis-monochlorotriazinyl dyes used widely in the dyeing of cotton textiles.
Biological pretreatment of a chemical plant wastewater in high-rate moving bed biofilm reactors
Authors: Rusten Bjørn , Johnson Chandler H. , Devall Steve , Davoren Dennis , Cashion Bryan S.
Published: May 2018

The Moving Bed Biofilm Reactor (MBBR), where the biomass is attached to small plastic carrier elements that move freely along with the water in the reactors, has been tested for biological pretreatment of a complex chemical industry wastewater. The MBBRs were tested at organic loads up to 53 g BOD5/m2d and always removed the easily biodegradable BOD fraction, ranging from about 60 to 80%. At organic loads from 10 to 20 g BOD5/m2d slowly biodegradable organic matter was also metabolized, sometimes removing more than 95% BOD5. After polishing in an activated sludge unit, the final effluent had an average concentration of only 3.4 mg filtered BOD5/l. With a very high specific biofilm surface area, MBBRs followed by activated sludge offer a compact process combination for complete biological treatment of chemical industry wastewaters.
Treating high-strength nitrate wastewater by three biological processes
Authors: Chen Shing-Der , Chen Chiu-Yang , Wang Yu-Feng
Published: May 2018

Three different types of bioreactors including an activated sludge reactor (ASR), a biologically mediated activated carbon fluidized bed reactor (BAFBR) and an upflow immobilized cell reactor (UICR) were studied. The results suggest that the carbon-nitrogen equivalent (CNE) ratio (in terms of CODN) when using ASR to treat the wastewater will decrease as the sludge age increases while it will increase slightly as the influent concentration increases. The CNE ratios for BAFBR and UICR are 3.67 and 3.61 respectively. For the test between the two different growth types, the CNE ratio of suspended growth will be lower than the one of attached growth.

The alkalinity-nitrogen equivalent (ANE) ratio (in term of Alk/N) for ASR is 3.78, for BAFBR it is 3.54, and for UICR it is 3.63. These ANE ratios are comparable with the theoretical value of 3.57. Under different operating conditions, slight changes of microorganisms are detected in Scanning Electron Microscope observation, but the dominant species, bacillus group, showed superior growth in all cases. Tests with the immobilized cells, biofilms will grow on the surface of them at the end of operation and the subsequent biochemical reactions will concentrate on the outer layer of biofilms.
Life cycle assessment: comparing strategic options for the mains infrastructure - Part I
Authors: Dennison F. J. , Azapagic A. , Clift R. , Colbourne J. S.
Published: May 2018

This paper presents the preliminary results of a Life Cycle Assessment (LCA) study which aims to compare two different potable water pipe materials: ductile iron (DI) and medium density polyethylene (MDPE). Stages where environmental impacts may be reduced in the life cycle of these pipes have been highlighted. A takeback scheme between water companies and pipe suppliers has been identified as an environmental improvement to the current disposal stage of the pipe life cycle. Potential exists for dual-use or reuse of abandoned mains.
Design of an efficient tannin extract effluent treatment system
Authors: Etiégni L. , Wakoli M. , Ofosu-Asiedu K.
Published: May 2018

A study was undertaken on the combined wastewater effluent from a Tannin extract plant (90%) and a Mushroom Production Unit (10%). The effluent had BOD5 of 2350 mg/l, COD of 4600 mg/l, and high levels of total suspended solid (0.43-4.20 mg/l), phosphorus (2078 mg/l), free ammonia (2982 mg/l) and colour index of 50 to 150°H. These values are effluent Standards of Eldoret Town in Kenya. To address these problems, three potential treatment processes were considered: VITOX system using pure oxygen, lagoon evaporation system, and Step-alum coagulation/flocculation process using wood ash leachate for pH adjustment. The latter was chosen because of its efficiency for not only BOD5, COD, phosphorus and free ammonia reduction but also for the complete colour removal when alum was added in two stages as laboratory Jar-tests indicated. A plant was subsequently designed that incorporated a two-step alum coagulation/flocculation process in two upflow tanks with wood-ash leachate for pH adjustment during and after flocculation.
An assessment of the feasibility of anaerobic digestion as a treatment method for high strength or toxic organic effluents
Authors: Sacks J. , Buckley C. A. , Senior E. , Kasan H.
Published: May 2018

The anaerobic digestion process converts organic materials into a methane-rich biogas. The KwaZulu-Natal region has the potential to attract a significant amount of industry. The objective of this research was to assess the feasibility of using anaerobic digestion as a treatment method for high-strength or toxic organic effluents. A strategy was developed to evaluate the degradability and toxicity of effluents and, ultimately, predict the efficiency of treatment in a full-scale digester. This paper details the strategy and investigates the degradation potential of a textile size effluent (COD ca. 140,000 mg/l). The ultimate degradability of the effluent was determined as well as the concentrations and volumes, which could be treated effectively. The inhibitory components of the size effluent were found to be Plystran (10 mg/l) and the biocide (5 mg/l). Anaerobic digestion was found to be feasible, on a laboratory-scale. These results are being applied for scale-up, to full-scale implementation in an existing anaerobic digester.
Further Evaporation and Final Treatment of Process-Water Concentrates
Authors: McKeough Paterson , Fagernäs Leena
Published: May 2018

The study is part of a longer-term effort aimed at developing a separate treatment process for evaporation-concentrates of paper-mill process waters. This article deals with research on the two key processing steps; namely, the further evaporation and the final treatment of the concentrates. In laboratory experiments, various feed waters, including several different TMP filtrates, were evaporated to high dry-solids contents. The condensates recovered in most experiments contained relatively small amounts of organic matter. The extent of vapourisation of organic acids, relative to water, increased somewhat with increase in dry-solids content. Two TMP concentrates from large-scale evaporation plants were further concentrated in a pilot-scale forced-circulation evaporator. Viscosity was the factor limiting the extent of concentration. Using an evaporation temperature of about 80°C, the maximum dry-solids contents achieved with the two different concentrates were about 45 wt% and about 60 wt%, respectively. Fouling of heat-transfer surfaces was observed with both concentrates. A techno-economic evaluation of final-treatment options for alkali-rich concentrates is under way. According to intermediate results, molten-phase combustion processes would not require support fuel once the dry-solids content of TMP concentrate exceeds about 50 wt%. The aim of future work is to optimise the overall treatment process.
Plywood Mill Water System Closure by Dissolved Air Flotation Treatment
Authors: Jokela P. , Keskitalo P.
Published: May 2018

In plywood industry water is mainly needed for soaking the logs. Dissolved air flotation with chemical precipitation was found to be a suitable treatment method for the soaking basin overflow of a plywood mill using birch as raw material. According to pilot treatment studies over 90% reductions of the suspended solids are possible with a hydraulic surface load of 6.5 m3/(m2h). In subsequent experience in full scale following reductions have been achieved: suspended solids 93%, BOD7 50%, CODCr 57%, P 92% and N 52%. Two-thirds of the flotation treated water is led to flue gas scrubbers and circulated back to the soaking basin. Optionally water can be led to the heat recovery, too. One-third of the flotation treated water is disposed of as the mill effluent. Concentrations of organic matter in the system have been reduced after the addition of flotation indicating the possibility of further closure. However, due to the use of aluminium sulphate in coagulation, aeration is needed for sulphate reduction prevention. Further closure of the water system is possible in the future if the heat recovery is renovated, preventing the increase of the water temperature (now 37°C) which otherwise might cause occupational safety hazards.
In-Mill Biological Treatment for Paper Mill Closure
Authors: Malmqvist Å. , Ternström A. , Welander T.
Published: May 2018

The installation of in-mill biological treatment for reducing the concentration of dissolved organic matter and microbial growth in the whitewater system h as been shown to be an interesting alternative for facilitating further closure of paper mill water circuits. In the present study the possibility of operating biological treatment of whitewater from different types of paper production under the environmental conditions prevailing in respective whitewater system, i.e. temperatures between 37 and 52°C and pH-values from 3 to 8. It was shown that high removals of soluble COD, 70-90%, could be achieved even at high temperatures and non-optimal pH-levels. Laboratory scale whitewater systems operated with and without a bioprocess were used for studies of the effect of a bioprocess on key parameters such as slime growth, spore formers and odorous compounds. The introduction of a bioprocess in the whitewater circuit effectively lowered the amount of soluble organic matter and eliminated odorous VFA. However, the operation strategy and control of the bioprocess showed to be crucial, especially the dosing of nutrients, in order to avoid increased rather than decreased biofilm growth in the whitewater system.
Anaerobic Thermophilic (55°C) Treatment of TMP Whitewater in Reactors Based on Biomass Attachment and Entrapment
Authors: Jahren Sigrun J. , Rintala Jukka A. , Ødegaard Hallvard
Published: May 2018

Thermomechanical pulping (TMP) whitewater was treated in thermophilic (55°C) anaerobic laboratory-scale reactors using three different reactor configurations. In all reactors up to 70% COD removals were achieved. The anaerobic hybrid reactor, composed of an upflow anaerobic sludge blanket (UASB) and a filter, gave degradation rates up to 10 kg COD/m3d at loading rates of 15 kg COD/m3d and hydraulic retention time (HRT) of 3.1 hours. The anaerobic multi-stage reactor, consisting of three compartments, each packed with granular sludge and carrier elements, gave degradation rates up to 9 kg COD/m3d at loading rates of 15-16 kg COD/m3d, and HRT down to 2.6 hours. Clogging and short circuiting eventually became a problem in the multi-stage reactor, probably caused by too high packing of the carriers. The anaerobic moving bed biofilm reactor performed similar to the other reactors at loading rates below 1.4 kg COD/m3d, which was the highest loading rate applied. The use of carriers in the anaerobic reactors allowed short HRT with good treatment efficiencies for TMP whitewater.
Effects of Pulp and Paper Mill Effluents on Reproduction, Bile Conjugates and Liver MFO (Mixed Function Oxygenase) Activity in Fish at Southern Lake Saimaa, Finland
Authors: Karels Aarno , Soimasuo Markus , Oikari Aimo
Published: May 2018

Reproductive indices like gonad size, fecundity, egg size and sex steroid levels of estradiol-17β and testosterone, vitellogenin in the blood as well as bile conjugates and liver 7-ethoxyresorufin O-deethylase (EROD) activity were studied in populations of perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) and experimentally exposed juvenile whitefish (Coregonus lavaretus L. s.l.) at the Southern Lake Saimaa (S.E. Finland). Our studies showed that the introduction of elemental chlorine free (ECF) bleaching and secondary treatment of effluents in a modern activated sludge plant at the mill in 1992 have substantially reduced the exposure of feral and caged fish to organochlorines. The liver EROD activity was noticeably lower in feral and caged fish near the mill indicating lesser impacts on the liver mixed function oxygenase (MFO) system. However, at the mill site, liver EROD activies in feral and caged fish still tend to be one to four times higher than at the reference sites. Significantly decreased plasma estradiol-17β and testosterone concentrations in perch and roach in the period of development of the gonads (autumn and winter) indicate that there were endocrine disrupting compounds present in the lake receiving ECF pulp and paper mill effluents. Cause-effect relationships, however, are difficult to establish.
Biomarker Responses by Crucian Carp (Carassius Carassius) Living in a Pond of Secondary Treated Pulp Mill Effluent
Authors: Kukkonen J. V. K. , Punta E. , Koponen P. , Paranko J. , Leppänen H. , Holopainen I. J. , Hyvärinen H.
Published: May 2018

Biochemical and histological biomarkers by the adult crucian carp (Carassius carassius (L.)) living in a biologically treated pulp mill effluent were studied. Enocell pulp mill in Uimaharju, Finland, discharges its effluents through a waste water pond to the River Pielisjoki. This pond harbours an introduced crucian carp population that apparently reproduces on site. The objective of the present study was to measure possible hormonal effects of treated pulp mill effluent on crucian carps living in a wastewater pond. Adult fish were collected for analysis by traps. A reference population was sampled from a small natural pond. Blood and bile samples were taken for analyses of hemoglobin, hematocrit, testosterone, triiodothyronine (T3), thyroxine (T4), vitellogenin, organic chlorine compounds, resin acids and neutral wood-based compounds. In addition, a histological analysis of male gonads was made.

The exposed fish had higher concentration of organic chlorine compounds, resin acids and β-sitosterol in bile compared to the reference fish. The same compounds could also be found in sediment of the wastewater pond. The exposed male fish had higher liver somatic index (LSI), lower gonad somatic index (GSI), lower haemoglobin and haemocrit, but higher T3 than in the reference fish. In addition, in an average, increased plasma testosterone concentration and decreased thyroxin (T4) levels were found in the exposed male fish. No vitellogenin production was found in the exposed male fish and some females showed decreased vitellogenin levels. The histological structure of the gonads in the exposed males was normal. The results suggest more anti-estrogenic than estrogenic effects of pulp mill effluents on the crucian carp.
The Occurrence and Bioavailability of Retene and Resin Acids in Sediments of a Lake Receiving BKME (Bleached Kraft Mill Effluent)
Authors: Leppänen H. J. T. , Oikari A. O. J.
Published: May 2018

Retene (7-isopropyl-1-methylphenantrene) is an alkyl substituted PAH derived primarily from bacterial aromatization of abietic type resin acids. Retene has been shown to induce cytochrome P450 1A in rainbow trout whereas e.g. dehydroabietic acid does not induce it. We analysed resin acids and retene in sediments from seven sites receiving pulp and paper mill effluents from 4 mills, and from two reference sites. All mills have employed treatment of waste waters by activated sludge. The highest concentration of retene measured in sediment was 1600 μg/g d.w. (11 700 μg/g organic carbon, OC) while the highest concentration of resin acids was 1500 μg/g d.w. (9 300 μg/g OC). Downstream from the point (12 km) of bleached kraft mill effluent discharge, the concentration of retene at the depth of 5-10 cm in sediment was still 16 μg/g d.w. (650 μg/g OC) and the concentration of resin acids 139 μg/g d.w. (1700 μg/g OC). Background concentration for retene on the upstream reference site was below 0.1 μg/g d.w and for resin acids below 70 μg/g d.w. Substantial concentrations of retene (54 μg/g d.w.) and resin acids (1470 μg/g d.w.) were also detected in sedimenting particles collected at the sediment sampling sites. When the concentrations and sedimentation rates before and after the installation of activated sludge systems were compared, the effect of improved waste water treatment on total amount of sedimenting resin acids and retene (μg/m2/day) is clear. To assess the bioavailability of retene we analysed its concentration in the bile of feral fish caught 1-2 km downstream of pulp and paper mill. Data on roach shows that retene in sediments can be bioavailable to fish feeding on benthic food chain.
Wastewater Sludge Dewatering for Champion-Hamilton Treatment Facility
Authors: Ward Roscoe F. , Huston Billy
Published: May 2018

Paper mills are under constant pressure to increase their profits and to reduce their wastewater treatment costs. Champion International Mill in Hamilton, Ohio, is not an exception. The mill produces 340 to 365 tons/day of coated and uncoated printing and writing papers. Prior to 1996, Champion used less than 60 tons/day of secondary fiber. The usage of secondary fiber has increased to 100 to 114 tons/day. In 1996 improvements were made in the mill to reduce fiber losses. At that time the corporation also changed suppliers of polymers. As a result of these changes, the wastewater treatment plant saw its sludge disposal costs increasing. The solids from their screw presses decreased from 55% to 48%. This paper reports the series of options that were examined to improve the dewatering and to lower disposal costs. Included are changes in polymers and polymer applications, changes in the chemical sludge mixing, improved press orifice cleaning, and screw press motor load control systems. The effects of these changes have resulted in improved dewatering and the potential for even higher solids in the sludge cake. The economics of the sludge dewatering system are reviewed.
Composting of Forest Industry Wastewater Sludges for Agricultural Use
Authors: Rantala P.-R. , Vaajasaari K. , Juvonen R. , Schultz E. , Joutti A. , Mäkelä-Kurtto R.
Published: May 2018

The feasibility of composting of pulp and paper industry sludges was studied. The aim was to study the progress of the composting process and the toxicity and applicability of the sludges in agriculture. Five different sludges were used: two biosludges and three biosludge and primary sludge mixtures. The sludges were composted in seven piles, two smaller of them founded with leachates collection systems. The piles were monitored throughout the composting period by physical measurements, chemical analyses and toxicity tests. Also the lignin concentrations were measured from the sludges and from the soil as well as the amount of mycelium.

The results showed that all sludges were easily composted and they will be suitable for the use as soil improvement in agricultural plant production. Toxicity of the sludges decreased during composting and all the sludges were proved to be non-toxic at the end of the composting. Heavy metal concentrations were low in all sludges and leachates. The leachates were also non-toxic and the concentrations of nutrients were low.
Color Removal of High Strength Paper and Fermentation Industry Effluents with Membrane Technology
Authors: Koyuncu I. , Yalcin F. , Ozturk I.
Published: May 2018

This paper presents the pilot plant studies on the biologically treated effluents from the pulp and paper and fermentation industry effluents by using two stage membrane treatment (Ultrafiltration(UF) and reverse osmosis(RO), (brackish water(BW) and seawater(SW)) membranes). In the first part of the study, the combination of UF and RO treatment resulted in very high removals of COD, color and conductivity for the pulp and paper industry effluents. At the end of one single pass with SW membrane, the initial COD, colour and conductivity values were reduced to 10-20 mg/l, 0-100 Pt-Co units and 200-300 μs/cm, respectively. The influent, UF permeate, BW permeate and SW permeate conductivities were 6000-6700 μs/cm, 5500-5900 μs/cm, 1000-1500 μs/cm and 200-300 μs/cm, respectively. Almost complete colour removals were achieved in the RO experiments with SW membranes. RO studies with BW membranes were also performed to the same permeate from the first stage UF study. In the second part of the study, ultrafiltration and reverse osmosis membranes were evaluated for their suitability in separating color and COD from the different wastewater streams generated by the fermentation industry. Three different wastewater stream, including the anaerobic treatment plant effluents of plant A and B, the aerobic treatment plant effluent of plant B have been tested during the runs. The overall removal efficiencies of COD, Color, Conductivity, NH3-N were found as 90-95%, 95-97%, 85-90% and 80-90% respectively with 85-90% recovery after UF and RO membranes for all these wastewater streams. Applying membrane technology to these complex industrial wastewaters, color problems of treatment plant effluents can be solved effectively.
Biodegradation of EDTA in Pulp and Paper Mill Effluents by Activated Sludge
Authors: van Ginkel C. G. , Kester H. , Stroo C. A. , van Haperen A. M.
Published: May 2018

Activated sludge systems operated under alkaline conditions remove EDTA. To improve EDTA removal a better understanding of EDTA biodegradation and its intermediates as well as knowledge of kinetic parameters are a prerequisite. Activated sludge appeared to degrade EDTA via ethylenediaminetriacetate (ED3A). The sludge was able to split ED3A into readily biodegradable iminodiacetic acid and iminoacetaldehydeacetate. The maximum growth rate of EDTA-grown sludge was approximately 0.15 days−1. The Km for EDTA and maximum oxidation rate of EDTA-grown sludge were 10 mg/L and 135 mg O2 g−1 SS day−1. Specially cultivated activated sludge degraded EDTA under neutral conditions and was capable of degrading the FeEDTA complex at a low rate. Bioaugmentation of EDTA-grown sludge enabled EDTA removal in a treatment system under neutral conditions.
Polish experience with sewage sludge utilization in reed beds
Authors: Zwara W. , Obarska-Pempkowiak H.
Published: May 2018

The problem of utilization and management of sewage sludge originating from small wastewater treatment plants is still unsolved in Poland. One of the waste-free technologies of sludge utilization is the reed bed method. Two experimental facilities of this type have been operating for four years in the Gdansk Region: a reed bed in Darżlubie and a reed lagoon in Swarzewo. The investigation was aimed at evaluating the influence of the storage on chemical and biological properties of sewage sludge deposited in beds. Tests were carried out in the period of two years. Moisture, organic matter, total nitrogen and total phosphorus contents as well as coli index, Clostridium perfringens index and number of Ascaris lumbricoides eggs analyzes were measured. Analyses of contents of heavy metals Cu, Pb, Ni, Zn, Cr and Cd for sludge samples from Darżlubie were additionally carried out. Tests proved that the utilization of sludge in reed beds allows using the end product as a fertilizer in agriculture. The most important problem is increasing of heavy metals content and number of Ascaris lumbricoides per mass of sludge during long time storage.
Full scale experiences with small sequencing batch reactor plants in Bavaria
Authors: Helmreich B. , Schreff D. , Wilderer P.A.
Published: May 2018

The number of sequencing batch reactor (SBR) plants in operation world-wide has been growing, but scientific process evaluation has not been adequately executed, and very little quantitative information is available on the actual performance of those systems. Trial and error approaches are prevailing. Consequently design engineers and water authorities are left in a rather difficult situation. To get an overview of the performance of SBR plants in operation in the State of Bavaria, Germany, the performance of the existing municipal SBRs has been investigated. The plants investigated comply with the discharge regulations, but in some cases only with the aid of secondary polishing ponds. Most of the system failures observed were caused by inadequate actions of the operators. Energy consumption was in the range of 56 kWh/(PE, a), and excess sludge production varied between 0.25 and 0.81 kg/kgCOD depending on the influent suspended solid loading.
Performance of family-size sequencing batch reactor and rotating biological contactor units treating sewage at various operating conditions
Authors: Akunna J.C. , Jefferies C.
Published: May 2018

Field trials were carried out using two types of package units designed for the treatment of domestic sewage from individual households. One of the units was a commercially available rotating biological contactor (RBC) system. The other was a newly developed sequencing batch reactor (SBR) system. Trials were carried at the site of a local sewage treatment plant where degritted raw sewage from a combined sewerage network was fed to the two units for a period of four months. Both units produced good effluent quality, well below 20/30 (BOD/SS) during steady-state performance. However, shorter start-up time was observed with the SBR unit together with better effluent quality (up to BOD<10 mg/l and SS<15 mg/l). Furthermore, the SBR unit produced effluents with ammonia nitrogen and total phosphorus levels of 3 mg/l and 2 mg/l respectively, for influent levels that varied from 20 to 60 mg N-NH3/l and from 15 to 17 mg/l of total phosphorus. On the other hand, significant nutrient removal did not seem tohave occurred in the RBC unit. During testing to meet the requirements of British Standard (BS 6297), it was observed that the SBR can tolerate shockloads and periods following zero flow better than the RBC unit.
Application of activated sludge and biofilm sequencing batch reactor technology to treat reject water from sludge dewatering systems: a comparison
Authors: Arnold E. , Böhm B. , Wilderer P.A.
Published: May 2018

Side stream reactors to treat reject water from sludge dewatering facilities may be considered to be small treatment plants embedded in large ones. Combination of main stream and side stream treatment provides a number of advantages. Of major importance is that tailored processes can be employed for the two waste streams very different in composition and concentration. Pilot scale experiments were conducted to study the applicability, and to compare the performance of two types of Sequencing Batch Reactor (SBR) systems, an activated sludge and a biofilm SBR. The reactors were operated to achieve nitrification only. Subsequently, the effluent of the reactors is fed into the anoxic zone of the main stream activated sludge plant to achieve denitrification. In general it can be stated that both, activated sludge and biofilm SBR systems are applicable for treating reject water of high ammonia loading. Nitrogen removal efficiencies of more than 90% could be obtained with both systems. If complete nitrification without denitrification is to be achieved, pH control is necessary. However, the amount of sodium hydroxide required for adjusting the pH during nitrification is significant. Foam development and accumulation caused major problems, especially during the early stage of start up. But the time proceeding, and by changing the type of polyelectrolyte used in the sludge dewatering process foam problems could be kept under control.
Strategies for dealing with piggery effluent in Australia: the sequencing batch reactor as a solution
Authors: Edgerton B.D. , McNevin D. , Wong C.H. , Menoud P. , Barford J.P. , Mitchell C.A.
Published: May 2018

Currently the accepted practice for swine wastewater disposal is lagoon stabilisation followed by land application. This disposal method can exacerbate odour emissions and contribute to soil contamination and eutrophication of waterways. Intensification of the pig industry has increased the impact of individual piggeries; this combined with tightening legislation is causing the pig industry in Australia to look at alternative treatment methods. A pilot scale sequencing batch reactor (SBR) was built to treat piggery wastewater. It achieved NH4+ and odour reductions of greater than 99% as well as 79% removal of COD and a 49% reduction of PO43−on a mass balance basis. The reactor experienced problems with foaming for the first 2 months of operation, which was controlled with vegetable oil until the foaming stopped. Struvite formation also occurred within the reactor and influent pipes but it was calculated that sufficient nutrients were removed to prevent precipitation down stream of the SBR.
Evaluation of the alternative treatment processes to upgrade an Opium alkaloid wastewater treatment plant
Authors: Sevimli M.F. , Aydin A.F. , Öztürk Ì. , Sarikaya H.Z.
Published: May 2018

The aim of this study is to characterize the wastewater from an opium alkaloid processing plant and to evaluate alternative treatment techniques to upgrade an existing full-scale biological activated sludge treatment plant having problems of high residual COD and unacceptable dark brown color. In this content firstly, long term operational records of the two stage aerobic activated sludge treatment plant of the opium alkaloid factory located in Afyon province of Turkiye were evaluated. The operating results for the last three years were statistically analyzed and median and 95-percentile values were determined for the parameters including chemical and biological oxygen demand (COD and BOD5) and treatment efficiencies. Specific wastewater generation was found as 6.7 m3 per ton of the opium capsule processed. In the following stage of the study, three additional treatment processes were experimentally tested: anaerobic pretreatment, post treatment of aerobically treated effluents with lime and ozone. Pilot scale upflow anaerobic sludge blanket reactor (UASBR) experiments have demonstrated that about 70 percent of the incoming COD can be removed anaerobically. Chemical treatability studies with lime for the aerobically treated effluent have shown that about 78 percent color and 46 percent COD removals can be obtained with lime dosage of 25 gl−1. Post treatment of the effluents of the existing two stage aerobic treatment with ozone also resulted in significant color and COD reduction.
Four-year undergraduate course in environmental engineering in Germany
Authors: Fettig J. , Miethe M. , Rathke K.
Published: May 2018

For ten years, the Division of Applied Science, University of Paderborn, has gained experience with a four-year undergraduate environmental engineering programme. Up to now, more than 400 graduates have successfully entered a professional career, proving that the educational concept is accepted by the employment sector, e.g. consultants, industry and authorities. Important aspects of this concept are the combination of civil engineering - as a core engineering field - with natural environmental sciences in the basic studies, the coverage of all environmental compartments in the main studies before specialisation in one area, and a strong practical component of the curriculum both inside and outside the university.
The European Junior Scientist Workshops - a flying start for doctoral students
Authors: Schilling W.
Published: May 2018

In this paper a workshop format is described that proved to be successful to introduce young researchers such as doctoral students into ongoing research in their subject. The workshop stimulates active participation and helps to create an international network. The origin and history, the main features behind the concept and the experience so far are described. Future options and prospects are briefly discussed.
Biological hydrogen potential of materials characteristic of the organic fraction of municipal solid wastes
Authors: Okamoto M. , Miyahara T. , Mizuno O. , Noike T.
Published: May 2018

The purpose of this study is to investigate the biological hydrogen production potential of individual organic fraction of municipal solid wastes (OFMSW) by batch experiments. Seven varieties of typical organic solid wastes including rice, cabbage, carrot, egg, lean meat, fat and chicken skin were selected to estimate the hydrogen production potential. Among the OFMSW, carbohydrate produced the most hydrogen through biological hydrogen fermentation compared with proteins or lipids. Subsequently, the biological hydrogen production potentials of some individual carbohydrate were measured: cabbage, 26.3–61.7 mL/g-VS; carrot, 44.9–70.7 mL/g-VS; and rice, 19.3–96.0 mL/g-VS. The hydrogen percentages of the total biogas produced from cabbage, carrot and rice were 33.9–55.1%, 27.7–46.8% and 44.0–45.6%, respectively.
Full scale co-digestion of organic waste
Authors: Kübler H. , Hoppenheidt K. , Hirsch P. , Kottmair A. , Nimmrichter R. , Nordsieck H. , Mücke W. , Swerev M.
Published: May 2018

Operational results of a co-digestion facility were assessed over a period of 18 months. The organic fraction of municipal solid waste (OFMSW) contains a considerable amount of contaminants and grit (up to 6% w/w). A BTA-Pulper efficiently treated the different waste streams and converted a high amount of volatile solids (VS) into the digester feedstock. The seasonal fluctuations of the waste composition significantly influenced the biogas production. The impact of this seasonally variant degradability of VS had to be considered by evaluating the operation results. The waste streams investigated did not show any negative impact on digester performance. The hydraulic retention time (HRT) in the digester considerably affected the VS-reduction. Despite a considerable decrease of VS-degradation a reduction of HRT from 14 to 8 days slightly improves the gas production rate (GPR). An activated sludge system efficiently reduced the pollution of the effluent.The nutrient content of the anaerobic compostwas favourable and the content of pollutants was low. The facility produced surplus electrical power up to 290 MJ/t. An overall energy balance shows that the facility substitutes primary energy.