bluuebunny/crossref_metadata_2025 huggingface dataset:
Wastewater reclamation for use in snow-making within an alpine resort in Australia - resource rather than waste
Authors: Tonkovic Z. , Jeffcoat S.
Published: May 2018

The Mt Buller Alpine Resort is located approximately 200 km north of Melbourne, in Victoria, Australia. A wastewater treatment plant services the resort and currently treats to advanced nutrient removal standards. The treated effluent is presently discharged into the Howqua River.

Most Australian ski resorts are not blessed with abundant snow cover on a regular basis. Artificial snow allows most of the popular ski runs to operate for the whole of the season. At the Mt Buller resort, snow-making is presently limited by lack of water supply in the catchment. The conditions at Mt Buller resort present a unique opportunity to utilise reclaimed wastewater to allow increased snow-making capacity. It is one of the unique opportunities where the wastewater is valued as a resource rather than merely viewed as a waste problem.

Wastewater reclamation for snow-making will require additional treatment for pathogen removal. It is proposed that following advanced nutrient removal, the effluent will require further treatment, including membrane ultrafiltration, so as to ensure a minimum of four barriers for pathogen removal.

Pilot plant operation of a membrane ultrafiltration system commenced in June 2000 and will continue until the end of 2001, to primarily demonstrate the extent of pathogen removal.
Urine separating sewage systems - environmental effects and resource usage
Authors: Jönsson H.
Published: May 2018

Effects of urine separation on the environment and resource usage were estimated using the simulation package ORWARE. Measurements on the urine-separating system in the housing district Palsternackan in Stockholm and on the fertilising effect of the urine were used in the simulations.

The tenants were at home 65% of the time and separated 65% of the urine. Under these conditions, urine separation decreased the waterborne emissions of nitrogen and phosphorus by 55% and 33% respectively. Compared to the conventional system, urine separation increased the flow from the wastewater system to agriculture of plant-available nitrogen by a factor of 28, phosphorus by a factor of 1.35 and potassium by a factor of 23. Urine is a well-balanced complete fertiliser with very low concentrations of heavy metals. Urine separation conserved energy as long as the urine was transported distances shorter than 221 km to the field with a truck and trailer. If all the urine had been separated and transported only 1 km, the energy saving would have been 36%.

In this and in previous studies, urine separation proved to be an improvement over the conventional system as regards environmental effects and resource usage.
Computer aided decision support on choosing the right technology for sewer rehabilitation
Authors: Plenker T.
Published: May 2018

The decision, whether and how to rehabilitate a damaged sewer is a complex one. Detailed information available from sewer inspection can be used for evaluating its condition and determining the urgency of rehabilitation. There are various rehabilitation techniques, from conventional open trenching to newer trenchless construction. Municipal waste water departments and companies must use their tight budgets in the most efficient and responsible way.

Therefore, a decision support system for choosing the right/best sewer rehab technology is urgently needed. For a computer aided selection of the right technology for sewer rehabilitation a formalised weighing and ranking procedure should be used. That procedure should be based on a detailed description of the rehabilitation task. So the state of the existing sewer has to be identified, future technical requirements have to be formulated and specific local restraints taken into account. First, rehab technologies not capable of solving the problem under given constraints, are eliminated by “knock-out” criteria. Thus the number of potential solutions is reduced to those which are subsequently compared (computer aided) in pairs. There is no scoring hocus-pocus and criteria weighing in this decision system. The result is found just by comparing pairs of options on as many criteria as needed, and these criteria may be measured on different scales and need not be independent from each other.
Nitrate removal rate in a continuous column denitrification reactor using hydrogen generated by electrolysis with carbon anodes and stainless cathodes
Authors: Dadang S. , Kawanishi T. , Shimizu N. , Hayashi Y.
Published: May 2018

An autotrophic continuous denitrification process, using hydrogen generated by electrolysis with activated carbon anodes, was experimentally demonstrated to be an effective nitrate removal process. Several fixed bed columns with polypropylene packing and honeycomb shaped activated carbon anodes and stainless rod cathodes were set in a thermostat chamber at 30°C, and potassium nitrate enriched tap water as influent was supplied at various flow rates and electric currents. Although the anode is in the same column where microbial biomass grows, sufficient nitrate removal was observed. For example, almost complete removal of nitrate and nitrite was observed at a hydraulic retention time (HRT) as short as 1.8 h. A model assuming successive denitrification reactions and plug-flow process, nitrate reduction rate = k1[NO3−] [H2], and nitrite reduction rate = k2 [NO2−]H2]1.5 was proposed. Calculated results with k1 = 1.3 mmol−1 h−1 and k2 = 3.3 mmol−1.5•h−1 agreed well with all the experimental results.
Performance of coarse pore filtration activated sludge system
Authors: Alavi Moghaddam M.R. , Satoh H. , Mino T.
Published: May 2018

A coarse pore filter can be applied inside the aeration tank to facilitate the separation of sludge from liquid instead of sedimentation. This filter has pores, which are irregular in shape, and the pore size is bigger than those of MF. The objectives of the study were to maintain as much as MLSS in the activated sludge process with coarse pore filter and to investigate the performance under high MLSS condition. Small-scale reactor results so far show good quality of effluent specially after starting the sludge bulking in the system in terms of SS, TOC, DOC and turbidity. The average carbon removal for 62 days operation of this system was about 94% (based on effluent DOC) and 87% (based on effluent TOC). The average sludge yield in this system is about 0.44 kg MLSS/kg TOC which is about 0.24 kg MLSS/kg BOD. This amount is less than those of conventional activated sludge and trickling filter.
Photocatalytic degradation of explosives contaminated water
Authors: Lee S.-J. , Son H.-S. , Lee H.-K. , Zoh K.-D.
Published: May 2018

This study was undertaken to examine the degradation of TNT, RDX and HMX in a circular photocatalytic reactor with TiO2 as a photocatalyst. We examined the impact of parameters such as the initial concentration, initial pH of solution on rates of photocatalized transformation, and the mineralization. The results showed that photocatalysis is an effective process for the degradation of TNT, RDX and HMX. They could be completely degraded in 150 min with 1.0 g/L TiO2 at pH 7. An increase in the photocatalytic degradation of HMX was noticed with decreasing initial HMX. The rates of RDX and HMX degradation were greater in neutral pH than in acidic and alkaline conditions. In case of TNT degradation, the rate of degradation was the fastest at pH 11. Approximately 82% TOC decrease in the TNT degradation was achieved after 150 min, whereas TOC decrease in RDX and HMX was 24% and 59%, respectively. Nitrate, nitrite, and ammonium ions were detected as the nitrogen byproducts from the photocatalysis, and more than 50% of the total nitrogen was recovered as nitrate ion in every explosives.
Treatment of agricultural wastewater and reuse
Authors: Reimann W.
Published: May 2018

The use of membrane separation technology, such as ultrafiltration (UF) and subsequent reverse osmosis (RO), for purifying different types of low-contaminated wash water of carrots (COD = 1,314 mg/l) and wash water of different kinds of vegetables (COD = 2,280 mg/l) was investigated on a pilot scale to determine its suitability for reuse in the process. In both membrane processes, UF and RO, the permeate flux first decreased with increasing fouling (deposition of organic and inorganic substances on the membrane surface and in its pores). After that the membrane permeability (permeate flux) and selectivity (rejection of COD) remained constant on a stable level in spite of a concentration with a volumetric concentration factor of up to 39. The tests showed that water can be obtained with a quality complying with the German regulations by applying a process combination of UF and RO. It was found that the membranes gave a 5-log reduction for total bacteria, and no coliform bacteria were present in the permeate after RO. Using UF and RO, part of the wastewater can be recovered for reuse in the process if drinking water is used for the last step of vegetable washing.
Long-term experimental study of the aquatic plant system for polluted river water
Authors: Sato K. , Sakui H. , Sakai Y. , Tanaka S.
Published: May 2018

Water purification using artificial wetlands and aquatic macrophyte is attracting attention as a purification technology that can create rich ecosystems while imposing a minimal load on the environment. Because an aquatic plant system requires a large surface area, design specifications and maintenance methods that can obtain the optimum purification effect per unit surface area must be established. Large experimental facilities have been constructed beside a polluted river flowing into Lake Kasumigaura and have been used for a three-year experiment using several kinds of aquatic plants. This report summarizes the characteristics and the design load of the aquatic plant system based on this study and results from other aquatic plant facilities.
China's water environment at the beginning of the 21st century: challenges and countermeasures
Authors: Zhang K. , Wen Z. , Xhang X.
Published: May 2018

Water environment crisis is a common challenge throughout the world, and the situation is becoming worse. This paper analyzes the development trend of water environment worldwide, and then evaluates the status of China’s water environment and the progress in the work of protection of the water environment. According to the future development of economy and society in China, the paper discusses the severe challenges in water environment that China faces at the beginning of the 21st century and proposes related countermeasures.
Assessment of risk of infection due to Cryptosporidium parvum in drinking water
Authors: Masago Y. , Katayama H. , Hashimoto A. , Hirata T. , Ohgaki S.
Published: May 2018

The risk of infection of Cryptosporidium via drinking water was assessed using Monte Carlo simulation with the field survey data of the Sagami River watershed. The levels of Cryptosporidium in this river were found to follow the lognormal distribution. From the counted data, the median level of the Miyayama sampling point was estimated to be 5.7 oocysts per 100L. To calculate the annual risk of infection due to Cryptosporidium in drinking water, the Cryptosporidium level of Miyayama sampling point was used as the water source of the waterworks. The 95% percentile of the annual risk of infection was found to be 10−2.60. If the daily risk was eliminated when the level of Cryptosporidium in treated water exceeded 1 oocyst per 20L, the 95% percentile of the annual risk was reduced by about 1 log. To reduce the 95% value of the annual risk lower than 10−4, the risk of days with levels of Cryptosporidium in treated water exceeding 1 oocyst per 80L should be eliminated.
Toxicity assays to determine the start-up strategy for an anaerobic sequencing batch reactor (anSBR)
Authors: Ng W.J. , Ong S.L. , Tan K.Y. , Hu J.Y. , Lee L.Y. , Song L.F.
Published: May 2018

Addition of glucose as the co-substrate and the use of a water-based polymer to enhance granulation were studied with the aim of shortening the start-up period of an anSBR (anerobic sequencing batch reactor) for high-strength industrial wastewater treatment. An initial start-up feed composition consisting of 70% sucrose and 30% industrial wastewater was favorable to reduce the start-up time. Increase in the average particle size and reduction in settled supernatant turbidity was observed with increased water-based polymer addition up to a concentration of 0.1 m/L. Polymer dosages above 0.1 ml/L were undesirable as big and “flaky” flocs were formed which prevented the flocs from settling quickly. Addition of 0.005 ml/L to 0.1 ml/L polymer to the mixed liquor had no observable adverse effects on the anaerobic biomass metabolism. Instead, the addition of the polymer appeared to improve biogas production and had an overall positive effect on anSBR performance treating the industrial wastewater.
Pollutant runoff from non-point sources and its estimation by runoff models
Authors: Noguchi M. , Hiwatashi T. , Mizuno Y. , Minematsu M.
Published: May 2018

In order to attain a sound and sustainable water environment, it is important to carry out the environmental management of the watershed. For this purpose, knowledge on the pollutant runoff mechanism from non-point sources becomes very important especially under rainy conditions. At Isahaya, Nagasaki, Japan, a big project of construction of sea-dyke and reclamation is now going on, so reducing the pollutant runoff, especially from non-point sources, becomes more important. Some runoff models of rainwater are developed to predict the rate of pollutant loads from the non-point sources, and their results are compared with each other to investigate the accuracy of prediction. In this paper, runoff analysis of both rainwater and pollutants has been carried out using three models: the tank model, the kinematic wave (K-W) model, and a model using the digital elevation model (DEM). For precise estimation, it becomes necessary to identify the parameters included in these models. Here, total nitrogen has been considered as pollutants, and detachment rates are evaluated, correlated with a class of land use, soil type, and moisture content. Finally, it has been shown that pollutant runoff from non-point sources can be predicted fairly well, identifying the model parameter appropriately.
Use of nitrogen stable isotope ratio of periphyton for monitoring nitrogen sources in a river system
Authors: Toda H. , Uemura Y. , Okino T. , Kawanishi T. , Kawashima H.
Published: May 2018

In order to confirm the usefulness of the N stable isotope ratio of periphyton (mainly composed of attached algae) as an indicator for monitoring the N sources in river watersheds, we measured the isotope ratio of periphyton along the Chikuma River. In the river, both the concentrations of dissolved total nitrogen (DTN) and the δ15N values of periphyton increased downstream. Specific nitrogen loading rates (SNLR) calculated from administrative data also showed an increase downstream from 7 to 11 kg N ha−1 yr−1, with the increasing contribution by sewage and livestock waste from 6 to 40% to total N loading. There are significant positive relationships between the DTN concentration and the SNLR (r2 = 0.54, P<0.05), and the δ15N values of periphyton and the SNLR (r2 = 0.78, P<0.05). The increase in DTN concentration reflected the increase in input of N loading. The increase in δ15N of periphyton might reflect the increase in relative contribution by sewage and livestock waste down the river, especially the increase in sewage. The present study indicates the usefulness of the N stable isotope ratio of periphyton as an indicator for monitoring N sources in a river system.
A model for predicting sediment-water partition of toxic chemicals in aquatic environments
Authors: Shimazu H. , Ohnishi E. , Ozaki N. , Fukushima T. , Nakasugi O.
Published: May 2018

In order to investigate the characteristics of sediment-water partition of chemicals in aquatic environments using published data, we developed a model for predicting the sediment-water partition coefficient (Kp) as the sum of sorption to sediment organic matter and sorption to sediment inorganic matter. This model is so successful that the differences between Kp (median for a variety of Japanese water bodies) and pre-Kp (predicted Kp) are within one order of magnitude in 24 out of 28 chemicals.
From waste treatment to integrated resource management
Authors: Wilsenach J.A. , Maurer M. , Larsen T.A. , van Loosdrecht M.C.M.
Published: May 2018

Wastewater treatment was primarily implemented to enhance urban hygiene. Treatment methods were improved to ensure environmental protection by nutrient removal processes. In this way, energy is consumed and resources like potentially useful minerals and drinking water are disposed of. An integrated management of assets, including drinking water, surface water, energy and nutrients would be required to make wastewater management more sustainable. Exergy analysis provides a good method to quantify different resources, e.g. utilisable energy and nutrients. Dilution is never a solution for pollution. Waste streams should best be managed to prevent dilution of resources. Wastewater and sanitation are not intrinsically linked. Source separation technology seems to be the most promising concept to realise a major breakthrough in wastewater treatment. Research on unit processes, such as struvite recovery and treatment of ammonium rich streams, also shows promising results. In many cases, nutrient removal and recovery can be combined, with possibilities for a gradual change from one system to another.
Effect of dissolved oxygen concentration on the biofilm and in situ analysis by fluorescence in situ hybridization (FISH) and microelectrodes
Authors: Jang A. , Bishop P.L. , Okabe S. , Lee S.G. , Kim I.S.
Published: May 2018

A better understanding of microbiology and ecology of nitrifying bacteria in inner biofilms is an important part of improving process performance and control. Microelectrodes and fluorescent in situ hybridization (FISH) in biofilm research have been used to investigate the spatial distributions of various microbial activities in biofilms and have led to new experimental findings as well as modifications of the homogeneous assumptions in the biofilm kinetic models. The objective of this study is to try the combination of two methods, both FISH and microelectrode measurements, and to provide reliable and in situ information on nitrifying bacterial activity in biofilms. The characteristics of biofilm developed on tygon slides were different according to the change of dissolved oxygen (DO). When the DO increased from 2 to 10 μg DO/L, the rate of the biofilm thickness increased and its dry density changed from 50-70 to 25-90 mg/cm3. Ammonia oxidizing bacteria were not uniformly distributed in biofilm, and were found at the deeper layer where oxygen is depleted, they were detected primarily in the upper and middle layers of the biofilm.
Investigating consumer attitudes towards the new technology of urine separation
Authors: Pahl-Wostl C. , Schönborn A. , Willi N. , Muncke J. , Larsen T.A.
Published: May 2018

The technology of urine separation and the recycling of anthropogenic nutrients as fertilizer in agriculture are considered as major innovations to improve the sustainability of today's urban wastewater management. The acceptance of consumers will be key for the introduction of the new technology. Citizens will have to make important decisions in their role as tenants and owners of houses and as consumers buying products fertilized with urine. Consumer attitudes towards the new technology were explored in a number of citizen focus groups in Switzerland. Focus groups are deliberate, moderated group discussions with informed citizens on a certain topic. The information was provided by a computer based information system specifically designed for this purpose. The acceptance of individual citizens for the new technology proved to be quite high. The majority of the citizens expressed their willingness to move into an apartment with NoMix toilets and to buy food fertilized with urine. However, they were not willing to accept additional financial costs or efforts. Arguments related to long-term sustainability (closing nutrient cycles) were of less importance than arguments that relate directly to the effects of micropollutants on human and ecosystem health. For the introduction of the new technology on a wide scale it will thus be crucial to explore the fate and effects of micropollutants.
Enhanced biological phosphorus removal process implemented in membrane bioreactors to improve phosphorous recovery and recycling
Authors: Lesjean B. , Gnirss R. , Adam C. , Kraume M. , Luck F.
Published: May 2018

The enhanced biological phosphorus removal (EBPR) process was adapted to membrane bioreactor (MBR) technology. One bench-scale plant (BSP, 200-250 L) and two pilot plants (PPs, 1,000-3,000 L each) were operated under several configurations, including pre-denitrification and post-denitrification without addition of carbon source, and two solid retention times (SRT) of 15 and 26 d. The trials showed that efficient Bio-P removal can be achieved with MBR systems, in both pre- and post-denitrification configurations. EBPR dynamics could be clearly demonstrated through batch-tests, on-line measurements, profile analyses, P-spiking trials, and mass balances. High P-removal performances were achieved even with high SRT of 26 d, as around 9 mgP/L could be reliably removed. After stabilisation, the sludge exhibited phosphorus contents of around 2.4%TS. When spiked with phosphorus (no P-limitation), P-content could increase up to 6%TS. The sludge is therefore well suited to agricultural reuse with important fertilising values. Theoretical calculations showed that increased sludge age should result in a greater P-content. This could not be clearly demonstrated by the trials. This effect should be all the more significant as the influent is low in suspended solids.
Evaluation of polyaluminium ferric chloride (PAFC) as a composite coagulant for water and wastewater treatment
Authors: Gao B. , Yue Q. , Miao J.
Published: May 2018

Coal gangue is a kind of waste from coal mine processing. Polyaluminium ferric chloride (PAFC), a new type of inorganic composite coagulant, was prepared by using the waste from the Mineral Bureau of Yanzhou, China, hydrochloric acid and calcium carbonate as raw materials. The relationship between the stability of ferric ion and the ionic strength of solution was investigated. The zeta potential of PAFC hydrolysis products of PAFC and the coagulation performances under different pH value were discussed. The turbidity removal properties of PAFC, polyaluminium (PAC) and polyferric sulfate (PFS) were compared, and the color removal effect of PAFC for the wastewater containing suspended dyes was also tested. In addition, the coagulation performance of PAFC for actual wastewaters from petrochemical plant, iron and steel plant, and coal mining processing was evaluated. The experimental results suggest that PAFC took a maximum value of zeta potential at about pH 5.8 on the positive side. Compared with PAC, PAFC gives better turbidity removal performance in the range of pH from 7.0 to 8.4. PAFC gives good color removal performance on suspension dyes. PAFC also gives good wastewater purifying results for the actual wastewater. Therefore, PAFC is a high-effect and stable water treatment agent.
Non-woven fabric filter separation activated sludge reactor for domestic wastewater reclamation
Authors: Seo G.T. , Moon B.H. , Lee T.S. , Lim T.J. , Kim I.S.
Published: May 2018

A non-woven fabric filter was experimentally evaluated for solid-liquid separation in an activated sludge reactor as an alternative membrane. A polypropylene fabric filter (70, 50 and 35 g/m2) was used for the experiment. The pilot system was operated in A/O (Anaerobic/Oxic) type in which the filter module was submerged into the oxic compartment. The filtration module consists of 10 plate type rectangular filter elements with effective filtration area, 2 m2. Gravity filtration was carried out for solid-liquid separation by changing the water head 0.05–0.5 m without backwashing during the system operation. Initial permeate flux was set at 0.4 m/d. C/N ratio of raw wastewater was controlled at 4.5 in terms of BOD/T-N. The fabric filter system showed a good performance enough for domestic wastewater treatment. Effluent solid concentration was 3.2 mg/L (93.5% removal). COD removal efficiency was 91.6% producing an effluent concentration around 13 mg/L. 66% of total nitrogen removal could be obtained at the adjusted C/N ratio of influent wastewater. However phosphorus removal was very low at 23%. It was found that the initial flux of 0.4 m/d should be maintained for stable performance of the system.
Removal and recovery of phosphate and ammonium as struvite from supernatant in anaerobic digestion
Authors: Yoshino M. , Yao M. , Tsuno H. , Somiya I.
Published: May 2018

Removal of phosphorus and nitrogen is required to prevent eutrophication problems in lakes and enclosed coastal seas. And recovery of phosphorus from wastewater has been attracting attention because of lack in phosphorus resources in the near future. In this study, reaction kinetics and design parameters of struvite production are experimentally investigated by using basic reaction type and a draft-tube type reactors. Struvite production rate, which is a very important parameter in reactor design and efficiency estimation, is formulated in an equation consisting of a rate constant (k2), and magnesium, phosphate and ammonium concentrations. The value of k2 is shown to be increased with struvite concentration and mixing intensity in the reactor. The developed equation is applied to the results obtained from the draft-tube type reactor experiments and verified for its applicability. High struvite concentration of 10-25% is maintained in the draft-tube reactor experiments. 92% removal and recovery efficiency with effluent phosphorus concentration of 17 mg/L is achieved under the conditions of 4 minutes reaction time, pH of 8.5 and Mg/P molar ratio of 1.1.
Manufacturing artificial aggregates from industrial sludge and marine clay with addition of sodium salt
Authors: Tay J.H. , Hong S.Y. , Show K.Y. , Chien C.Y. , Lee D.J.
Published: May 2018

The potential of converting industrial sludge and dredged marine clay into building and construction materials as an alternative to disposal was investigated in this study. The industrial sludge was mixed with marine clay at various compositions and was shaped into round pellets to be used as concrete aggregates. The pellets were then dried and transferred into a high temperature kiln where they were heated at 1,135°C. The artificial aggregates were more porous then the normal granite aggregate. The occurrence of this condition was suspected to be attributed to two factors, viz. the firing temperature and the amount of sodium in the aggregates. To validate this hypothesis, the aggregates with and without added sodium chloride were fired at temperatures of 1,100 and 1,200°C. Results showed a reduction in the densities of the aggregates with the addition of sodium chloride and the increase in firing temperature.
The reaction mechanism of catalytic oxidation with hydrogen peroxide and ozone in aqueous solution
Authors: Park J.S. , Choi H. , Ahn K.H.
Published: May 2018

The sorption and catalytic oxidation of model compounds (pCBA and phenanthrene) and NOM on FeOOH were investigated using hydrogen peroxide and ozone, respectively. After oxidation with ozone, the hydrophobic, transphilic, and hydrophilic NOM fractions were isolated using XAD-8 and -4 resins to analyze the reaction characteristics. The sorption of pCBA was strongly dependent upon the pH, but phenanthrene exhibited a sorption behavior that was independent of the pH. In the case of NOM, the hydrophobic portion showed higher sorption affinity than hydrophilic and transphilic at pH 7.2. The concentrations of model compounds and oxidants were measured during the oxidations and the efficiency was compared for tests done with ozone alone and those using catalytic ozonation. Through the comparison of the sorption and decomposition of the model compounds, along with the effects of bicarbonate addition, mechanisms for catalytic oxidation with hydrogen peroxide or ozone were proposed, respectively.
Observations of blanket characteristics in full-scale floc blanket clarifiers
Authors: Chen L.C. , Sung S.S. , Lin W.W. , Lee D.J. , Huang C. , Juang R.S. , Chang H.-L.
Published: May 2018

We monitored the changes in concentrations, zeta potentials, sizes and capillary suction times of the solids flocs in the clarified water from eight floc blanket clarifiers of PingTsan Water Works of Taiwan Water Supply Company with low (<10 NTU) and high (>100 NTU) turbidity raw water. For the former, one-stage coagulation-sedimentation treatment was adopted which yielded a rather unstable blanket. Complete washout was noticeable when the PACl dosage was insufficient. On the treatment of high-turbidity raw water, on the other hand, the Works adopted the combined treatment process, that is, the raw water was first coagulated and settled in a pre-sedimentation tank, afterwards, its effluent was coagulated again and clarified in the clarifiers. The resulting flocs could form a networked blanket that was relatively stable to the shock load in raw water turbidity.
A simplified risk-based approach for process screening in municipal wastewater reclamation and reuse
Authors: Chu W.H. , Wang J.Y. , Kao C.M.
Published: May 2018

Reuse of municipal wastewater has become a promising solution to relieve the tension of increasing fresh water demand in many metropolitans. Although different advanced technologies are available to reclaim wastewater into premium quality, associated health effects are usually not properly assessed in reclamation process selection. A simplified risk-based approach developed for process screening and adaptation of health impacts as a consideration in reclamation process selection is discussed in this paper. This approach can be used to screen out unqualified processes and those with poor cost benefits. As a result, the design of wastewater reclamation could be enhanced to control the associated health impacts in wastewater reuse.
Biological treatment of printing ink wastewater
Authors: Zhang Y. , Shi H. , Qian Y.
Published: May 2018

Printing ink wastewater is usually very difficult to treat biologically and its chemical oxygen demand (COD) far exceeds standards of discharge. The COD in wastewater is usually 3,000 to 8,000 mg/L after flocculation and sedimentation. Herein, a strain of bacterium was isolated from the sludge and identified as Bacillus sp. and utilized to treat printing ink wastewater. The application of bacteria to degrade printing ink in wastewater is discussed in this paper. The influence of N and P sources on COD removal, and COD removal in combination with glucose was also discussed. More than 85 per cent of the COD could be removed using the proposed biological process. A novel internal airlift loop bioreactor with bacteria immobilized onto ceramic honeycomb support was used for the wastewater treatment.
Research on waste stabilisation ponds in the United Kingdom - initial results from pilot-scale facultative ponds
Authors: Abis K.L. , Mara D.D.
Published: May 2018

Three pilot-scale facultative ponds were constructed at Esholt wastewater treatment works in Bradford, West Yorkshire, UK. The ponds were operated in parallel to test the effect of surface BOD loading on performance and the maintenance of facultative conditions. The performance criteria adopted were BOD, SS and ammonia removal. The criterion for facultative conditions was the presence of an algal population maintaining aerobic conditions at the pond surface. Filtered BOD removal was found to be more than 90%, non-seasonal, and related to areal BOD loading. SS removal was also found to be non-seasonal, at around 95% but not related to areal BOD load. Ammonia removal was seasonal (32-48% October to March; 60-81% March to July) and related to areal BOD load. At the test loadings (60, 110 and 169 kg/ha.d) an algal population was not maintained in winter. The initial results indicate that a much lower loading is required to maintain facultative conditions than to optimise BOD and SS removal.
Waste stabilisation ponds upgrading at Blenheim and Seddon, New Zealand - case studies
Authors: Archer H.E. , Donaldson S.A.
Published: May 2018

Waste stabilisation ponds (WSP) have been a popular form of wastewater treatment in New Zealand both for large cities and small communities. Most WSP were constructed from 1960 to 1985 and were single ponds or a primary and secondary pond in series of similar size. Since 1995, improvements comprising primary and maturation ponds, with four to six cells in series have been constructed or retrofitted to original two cell ponds. The Seddon and Blenheim ponds include in-bank rock filters between maturation cells as a lower cost way of providing this feature for reduction of solids. Operating results show reduced variability in final effluent quality for BOD and SS. In addition, very good reductions of faecal coliform and enterococci have been achieved along with good reductions of ammonia and total nitrogen for most of the year except the middle of winter. Extensive use of rock as rip-rap bank protection and in the rock filters, appears to have provided sufficient extra surface area for a nitrifying biofilm to develop.
Infrared optical sensors for water quality monitoring
Authors: Mizaikoff B.
Published: May 2018

In-situ monitoring of water quality with particular emphasis on organic pollutants is a global priority topic in water analysis. Recent developments in optical sensor technology provide advanced analytical tools for continuous assessment of pollution levels in the liquid phase and in the gas phase. Infrared sensing schemes are among the most promising concepts due to inherent molecular specificity provided by absorption patterns of fundamental molecular vibrations of organic molecules. The advent of mid-infrared transparent optical fibers and waveguides, appropriate light source technology, such as quantum cascade lasers, and the potential for the development of highly integrated analytical devices based on microfabrication technology substantiates the trend towards spectroscopic sensing techniques. Chemical modification of the waveguide surface leads to enhanced analyte recognition based on tunable properties of enrichment or (bio)chemical recognition layers. Discussion of fundamental sensing technology is complemented by recent examples, highlighting the state-of-the-art in this dynamic research field.
Use of real-time data in environmental monitoring: current practices
Authors: Gunatilaka A. , Dreher J.
Published: May 2018

Water quality monitoring in Europe, especially in transboundary water courses has made steady progress during the last decades through establishment of international commissions. The main activities of these commissions include protection and management of the catchment, sustainable use of the river and establishment of Accident Emergency Warning Systems (AEWS). The latter could be effectively accomplished only through real-time monitoring. Concurrently real-time data have been found important for the monitoring of potable water intake points, wastewater treatment plants, estuaries and in aquaculture. With the recognition of the diversified demand, there are a number of questions to be answered such as: (1) are we satisfied with the existing monitoring systems? (2) is standardisation of the measuring instruments a necessity? (3) do we have foolproof systems for data capture and transmission? (4) are there adequate procedures to analyse vast amount of data generated? We have to answer these questions urgently as the demand for real-time monitoring has been drastically increased.
Characterisation of oxygen dynamics within a high-rate algal pond system used to treat abattoir wastewater
Authors: Evans R.A. , Fallowfield H.J. , Cromar N.J.
Published: May 2018

As part of a study examining the efficacy of high-rate algal pond treatment of high-strength abattoir wastewater, the oxygen dynamics of a pilot scale system were characterised. The relationship between photosynthesis and irradiance was investigated using online data collected throughout a year of operation under varying conditions of climate and wastewater quality. Changes in climate were reflected in changes in the net rate of photosynthesis in deep ponds, consistent with adaptation of algal populations to changing light intensity, whilst the response of shallow ponds was more varied. The use of online monitoring and the calculation in real time of photosynthetic rates should allow for improved design and management of full scale treatment systems and further the understanding of factors driving biological reactions within these systems.
Influence of changes of the wastewater composition on the applicability of UV-absorption measurements at combined sewer overflows
Authors: Stumwöhrer K. , Matsché N. , Winkler S.
Published: May 2018

The applicability of UV-absorption measurements at combined sewer overflows was investigated under different storm water conditions. Three specific rainfall events of different intensity, different duration and different intervals between the events were investigated. An individual evaluation of each single event resulted in an acceptable correlation between the UV absorption and the pollution measured as COD. A combined evaluation of the different events exhibited a very poor correlation which could not be used as pollution control parameter. Since the calibration procedure of the spectrometer used was not flexible enough to distinguish between different wastewater matrices from the different storm events the applicability of this type of spectrometer for the control of storm water overflows is questionable.
Concentrations and inactivation of Ascaris eggs and pathogen indicator organisms in wastewater stabilization pond sludge
Authors: Nelson K.L.
Published: May 2018

During treatment in wastewater stabilization ponds (WSPs) many pathogens, in particular helminth eggs, are concentrated in the sludge layer. Because periodic removal of the sludge is often required, information is needed on the concentrations and inactivation of pathogens in the sludge layer to evaluate the public health risk they pose upon removal of the sludge. In this paper, previous reports on the sludge concentrations of various pathogen indicator organisms and helminth eggs are reviewed and results from our own recent experiments are reported. The advantages and disadvantages of several methods for studying inactivation in the sludge layer are discussed, as well as implications for the management of WSP sludge. In our recent experiments, which were conducted at three WSPs in central Mexico, sludge cores, dialysis chambers, and batch experiments were used to measure the inactivation rates of fecal coliform bacteria, fecal enterococci, F+ coliphage, somatic coliphage, and Ascaris eggs. The first-order inactivation rate constants were found to be approximately 0.1, 0.1, 0.01, 0.001, and 0.001 d-1, respectively. The concentrations of all the organisms were found to vary both vertically and horizontally in the sludge layer; therefore, to determine the maximum and average concentration of organisms in the sludge layer of a WSP, complete sludge cores must be collected from representative locations throughout the pond.
Accounting for sensor calibration, concentration heterogeneity, measurement and sampling uncertainties in monitoring urban drainage systems
Authors: Bertrand-Krajewski J.-L. , Bardin J.-P. , Mourad M. , Béranger Y.
Published: May 2018

Assessing the functioning and the performance of urban drainage systems on both rainfall event and yearly time scales is usually based on online measurements of flow rates and on samples of influent and effluent for some rainfall events per year. In order to draw pertinent scientific and operational conclusions from the measurement results, it is absolutely necessary to use appropriate methods and techniques in order to i) calibrate sensors and analytical methods, ii) validate raw data, iii) evaluate measurement uncertainties, iv) evaluate the number of rainfall events to sample per year in order to determine performance indicator with a given uncertainty. Based on previous work, the paper gives a synthetic review of required methods and techniques, and illustrates their application to storage and settling tanks. Experiments show that, despite controlled and careful experimental conditions, relative uncertainties are about 20% for flow rates in sewer pipes, 6-10% for volumes, 25-35% for TSS concentrations and loads, and 18-276% for TSS removal rates. In order to evaluate the annual pollutant interception efficiency of storage and settling tanks with a given uncertainty, efforts should first be devoted to decrease the sampling uncertainty by increasing the number of sampled events.
Automation in sludge dewatering by novel on-line characterisation of flocculation
Authors: Sievers M. , Schroeder C. , Bormann H. , Onyeche T.I. , Schlaefer O. , Schaefer S.
Published: May 2018

A novel on-line method and system for characterisation of sludge flocs in view of improving sludge dewatering has been developed. The characterisation of sludge flocs was carried out after the conditioning or the flocculation process. The system uses a conventional CCD-line scan camera providing an on-line monitoring of the relative floc size distribution by image processing procedures. The image processing procedure has been re-evaluated and adapted to the practical dewatering results, obtained from a chamber filter press of 250 × 250 mm size. A good correlation between the calculated sensor signal and the sludge dewaterability of digested sludge in terms of the up-concentration factor was found. Although different sludge compositions and flocculation systems have been tested within the whole experimental period of six months, a good reproducibility of this correlation was also found. A well balanced floc size distribution is necessary showing that not too many but still some fine flocs and also not too large but compact flocs lead to improved dewaterability. This has been illustrated by an extended range of floc size measurements ranging between 50 mm and 29 mm. The conditioning monitoring system would be suitable for the control of production of good size-balanced flocs to compensate fluctuations in sludge characteristics of the sludge to be conditioned.
Novel monitoring concepts to acquire new water quality knowledge
Authors: Noij Th.H.M. , Bobeldijk I.
Published: May 2018

Two novel water quality monitoring concepts were developed: the HPLC-fingerprint for the monitoring of yet unidentified pollutants and the HPLC-Toxprint® for the recognition of (unknown) toxic or genotoxic compounds. The paper describes applications of both concepts. The HPLC-fingerprint is used for the evaluation of the overall water quality in addition to the monitoring of individual pollutants. Based on their occurrence (frequency, concentration, location) a listing of unknown priority pollutants is set up. Participating waterworks monitor for these compounds using a dedicated HPLC-DAD library that contains the required compound data (UV-absorbance spectrum, retention time index). In five years of experience with this concept, the HPLC-fingerprint was also found very suitable for the retrieval of new priority pollutants in existing HPLC-fingerprint databases, providing historic data on these new compounds. The HPLC-fingerprint concept was also used as an Early Warning System for accidental spills or sabotage. The HPLC-Toxprint was successfully applied in identifying genotoxicity (in the umu-test) in various waste water samples. By the application of LC-MS/MS genotoxicity could be assigned to acridine-derivatives in one of these wastewaters. To enable the evaluation of drinking water resources, the sensitivity of the HPLC-Toxprint was improved, now allowing the detection of pollutants with a 10% genotoxic potential as compared to 2-aminoanthracene (the positive control compound) at concentrations as low as 0.1 mg/l.
Hydrological information system based on on-line monitoring - from strategy to implementation in the Brantas River Basin, East Java, Indonesia
Authors: Marini G.W. , Weilguni H.
Published: May 2018

The worsening environmental situation of the Brantas River, East Java, is addressed by a comprehensive basin management strategy which relies on accurate water quantity and quality data retrieved from a newly installed online monitoring network. Integrated into a Hydrological Information System, the continuously measured indicative parameters allow early warning, control and polluter identification. Additionally, long-term analyses have been initiated for improving modelling applications like flood forecasting, water resource management and pollutant propagation. Preliminary results illustrate the efficiency of the installed system.
A computer simulation of the oxygen balance in a cold climate winter storage WSP during the critical spring warm-up period
Authors: Banks C.J. , Koloskov G.B. , Lock A.C. , Heaven S.
Published: May 2018

The paper considers factors that determine the oxygen balance in extreme climate waste stabilisation ponds during the critical spring warm-up period. At this time BOD load on the pond is a maximum, due to accumulation of wastewater under the ice during the winter. The paper describes the operation of a typical cold climate WSP and the events leading to a balanced steady state system as spring develops into summer. A mathematical model to simulate conditions within a batch fed experimental pond over the transient period is described. To model temperature changes in the water body experimental data were fitted to a generalised equation based on diurnal fluctuations in air temperature. The results are plotted in a normalised form and show the diurnal fluctuation and time lapse as the depth of the pond increases. Maximum daily water temperature lags behind maximum light intensity. Bacterial growth is simulated by a Monod kinetic model in which growth rate depends on initial substrate concentration; temperature compensation is applied using a temperature activity coefficient. Oxygen utilisation is calculated from substrate removal. Algal growth rate is more complicated as it is affected by temperature and light availability. Algal oxygen production potential is considered in terms of its primary metabolite yield, which is then used in a Monod equation to estimate the growth rate. The model uses a mass balance approach to determine dissolved oxygen concentration in the pond. The model is still in a simple form but shows reasonable agreement, in terms of events and time lapses, to measured parameters in experimental ponds recovering from ice cover.
Emission of H2S and mass balance of sulfur in anaerobic ponds
Authors: Paing J. , Picot B. , Sambuco J.P.
Published: May 2018

Anaerobic ponds are highly efficient at removing BOD from wastewater with a reduced land area requirement. However, their use is often limited because of the problem of odor release, primarily due to the emission of hydrogen sulfide (H2S). The experiments were conducted on full scale anaerobic ponds used for the primary treatment of urban wastewater under Mediterranean climatic conditions (south of France). A model was developed to estimate the emission of H2S from water characteristics (temperature, pH and sulfides concentration). The emission rate from anaerobic ponds varied between 20 and 576 mg-S/m2.d, leading to concentrations of H2S in the surrounding atmosphere between 0.2 and 5.2 ppm. These concentrations risked creating odor nuisances for nearby inhabitants. The whole of the results and the analysis of sulfur species in sludge permitted the production of a complete mass balance for sulfur. Methods of reducing the emission of odorous compounds were tested on a large scale. The recirculation of secondary effluent and the use of impermeable or permeable covers appeared to be the most interesting solutions.