bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developments in Laboratory Evaluation of Sewage Sludges Dewaterability
Authors: Lotito V. , Mininni G. , Spinosa L. , Lore F. 
Published: May 2018

Literature review shows that particle size distribution, water distribution and rbeological properties can play an important role in the evaluation of dewatering performance. Following a previous study on relationships between Theological parameters and filterability parameters, work has been addressed to the understanding of the influence of particle size and water distribution on specific resistance to filtration.
Tests were carried out on different types of sludge (raw, digested, conditioned). Two substantially different techniques for measuring the particle size distribution were used, showing that the mechanical technique (sieving) resulted in larger particle sizes than the optical (laser diffraction). Results showed that particle size distributions play a role in describing sludge filterability.
Whey Disposal: Recovery of Nutrients for Animal Feeding
Authors: Guirguis N. , Brosnahan C. , Hickey M. W. 
Published: May 2018

It has been estimated that over 50% of whey production world wide constitutes a pollution problem to the environment. A proportion of the work carried out to make use of whey nutrients has not been commercially viable. A simple process has been developed, at the laboratory and pilot plant scales, resulting in a complete recovery of nutrients from whole whey or whey fractions for animal feeding and no further waste or effluent is generated. The economics of the proposed process rely on efficient use of inexpensive ingredients (or waste materials, from other agricultural sources) to overcome the high cost of dewatering and drying.
Using this approach a number of products are possible. In the first product bentonite is used to precipitate whey protein which can be processed into a dry protein concentrate for use in intensive animal, poultry or fish production. This product compares favourably with conventional protein supplements such as meat and bone, soybean, or fish meal. The deproteinised whey, (mainly lactose and minerals) arising from this process, is concentrated and mixed with a carrier to produce a second product for ruminants that can compete with hay or grains. Further, whole whey may be used in a similar process.
Animal feeding trials with sheep and dairy cattle have demonstrated advantages of the developed whey products over conventional feed supplements for wool growth, live sheep export or milk production.
Treatment of a Domestic Wastewater with UASB Reactors
Authors: Gnanadipathy A. , Polprasert C. 
Published: May 2018

This study investigated a feasibility of employing pilot-scale upflow anaerobic sludge blanket (UASB) reactors to treat a domestic (or relatively low-strength) wastewater. Four 30-1 UASB reactors, each with a 0.15-m inner diameter and 2-m height were used in this study which was conducted at an average ambient temperature of 30°C. Three reactors were inoculated with different types of seed sludge, namely: sludge from a facultative waste stabilization pond, anaerobically digested sludge and sludge from a UASB reactor treating a distillery wastewater. The fourth reactor was started without inoculum and was studied for possible self inoculation. Domestic wastewater was mixed with a stock glucose solution to increase the influent COD concentrations to about 600 mg/l. All four reactors were started with a hydraulic retention time (HRT) of 24 h, and this HRT was later reduced to 12, 6 and 3 h, consecutively, corresponding to the organic loading rates (OLR) of 0.4-0.6, 0.9-1.4, 1.8-2.8 and 3.6-6.0 kg COD/(m3.d), respectively.
At the highest OLR or shortest HRT, there was about 90% removal of the influent COD in Reactors 1-3 while the methane (CH4) production rate was found to be 150 N1/kg COD removed with a methane (CH4) content of 75%. Reactor 4, without inoculation, could not develop sufficient amount of biomass to withstand the high OLR and its performance deteriorated at the HRT of 3 and 6h. The scanning electron microscopic (SEM) examinations of the sludge floc revealed the predominance of Methanothrix-like bacteria in all reactors. The experimental results obtained have suggested a technical feasibility of employing UASB reactors to treat domestic wastewaters. The facultative waste stabilization pond sludge and anaerobically digested sludge were found to be suitable inoculum sources for the UASB reactors treating this low-strength wastewater.
Anaerobic Digestion of Olive Oil Mill Effluent Pretreated and Stored in Municipal Solid Waste Sanitary Landfills
Authors: Boari G. , Mancini I. M. , Trulli E. 
Published: May 2018

Sanitary landfills of municipal solid waste (MSW) might be used to reduce the storage volume required at plants giving year-round treatment of olive oil mill effluent (OME). A landfill in the methanogenic stage could act as an anaerobic filter and reduce the pollutional load of the OME while also acting as a temporary storage tank.
In the present work, a lysimeter in pilot scale was used to simulate a cell of a sanitary landfill. It was filled with MSW screened by a 80 mm mesh sieve mixed to municipal sludge. Results show that when OME was spread on the top of the lysimeter at a loading rate not exceeding 0.4 kgCOD/d/m3 of reactor steady methanogenic activity was maintained in the layers of refuse and a 70% removal of COD was obtained in the OME leachate collected. Higher loading rates reduced methanogenic activity and COD removal efficiency. Nevertheless, the OME collected from the bottom of the landfill was more easily treated by anaerobic digestion than was the raw OME.
Anaerobic Treatment of the High Strength Wastes from the Yeast Industry
Authors: Çiftçi T. , Öztürk I. 
Published: May 2018

This paper presents the full-scale anaerobic treatment results from a fermentation plant producing baker's yeast from sugar beet molasses. The process of baker's yeast production generates high strength industrial effluents with a chemical oxygen demand (GOD) of 10 000-30 000 mg/liter. In addition to the sugar containing substances sulphur and nitrogen containing substances are added to the batch processes to promote cell growth and to control pH. This results in rather high concentrations of sulphate 0000-2700 mg/l) and ammonia (400-900 mg/l) in the wastewater.
The treatment plant at Pakmaya Izmit Factory has two different processes: anaerobic first-stage treatment and aerobic second stage treatment. The anaerobic first-stage treatment system includes a buffer tank, an acid reactor, two methane reactors, lamella separators, a gas storage tank and gas burning facilities. The anaerobic reactors were constructed as upflow anaerobic sludge blanket reactors (UASBR) with internal sludge recirculation facilities. The anaerobic reactors have been operating in series mode at mesophilic temperature ranges. Long term Organic Loading Rates (OLR) in the acid, the first and the second stage methane reactors have been averaging 9.8, 8.6 and 3 kg COD/m3·d respectively. Average COD removal is 75 percent in the anaerobic pretreatment stage. Average biogas production is 8000 m3/d, corresponding to a biogas conversion yield of 0.6 m3 per kg COD removed and it is equivalent to a netbioenergy recovery of 40 000 kWh/d.
Enhancement of Phosphorus and Nitrogen Removal with a Side Stream Biological Nutrient Removal Process
Authors: Eun Lee Sang , Soo Kim Kwang , Soo Kim Kap , Whoe Kim Chang 
Published: May 2018

Bench scale experiments and pilot plant studies (20 m3/day) on a side stream biological nutrient removal process (P/L process) were conducted for 3 years using primary effluent of two different sewage treatment plants as influent. The phosphorus removal efficiency was always higher than 90% resulting in an effluent T-P concentration lower than 0.5 mg/l while total nitrogen removal efficiency of the P/L process was less than 50%. However, total nitrogen removal efficiency could be improved to 88% with some modification of the process.
The presence of nitrate nitrogen higher than 2 mg/l in the phosphorus stripping tank significantly reduced the phosphorus release in the stripping tank. Phosphorus content of the sludge in the aeration basin was about 30% higher than that of the phosphorus stripping tank, however, phosphorus content in the aeration basin could become higher by recycling portions of the phosphorus rich supernatant to the aeration basin to utilize the phosphorus uptake capacity of the sludge in aerobic conditions more efficiently and also to reduce the alum requirement.
Upflow Anaerobic Sludge Digestion in a Phase Separation System
Authors: Lin Hsin-Yi , Ouyang Chaio-Fuei 
Published: May 2018

This paper aims to expand the knowledge about methods for improving the rate of solids hydrolysis, volatile acid formation and methane gas production. It studies the effects of phase separation and operational modes on the performance of the process. Two systems were investigated. The two-phase system consisted of a CSTR acid-phase digester and an upflow methane-phase digester, the one-phase system comprised of an upflow anaerobic digester. In order to provide optimal contact conditions and recycle liberated indigenous enzymes or cell biomass fractions, continuous recycling of the effluent sludges to the sludge bed of the reactor was used.
In general, the nonbiodegradable portion of the substrates contained in the mixed sludges was found to be about 45% on the basis of TVS. The TVS reduction of the two-phase system was 53%, this is higher than in the one-phase system. Methane production rate and methane content were 0.351 l/g TVS added and 66.6%, respectively.
Disinfection of Virus in Water by Active Oxygen Species
Authors: Hamada Akira , Hakoda Masafumi , Utsumi Hideo 
Published: May 2018

Identification of the species of active oxygen generated in water by chlorination or ozonation was carried out by the spin trapping method using DMPO as the spin trap agent with ESR spectrometry. On chlorinating with NaOCl solution (15 mg/litre), typical ESR signals for DMPO-OH adduct were observed. Increasing the concentration of NaOCl, however, caused complex spectra to appear. The addition of thiourea or D-mannitol, as a radical scavenger, did not significantly affect on the intensity of the signals. On ozonation, two radicals, DMPO-OH and an unknown radical, were always observed. These results indicate the generation of several radicals in the solution treated with NaOCl and ozone.
An interaction of the polio virus with ♦OH was also studied. The preliminary test showed that the ♦OH generated by Fenton's reaction slightly disinfected the virus. Precise tests changing the concentration of active oxygen and the reaction condition are currently in progress.
The Development of Rural Water Supply in the Province of Fayoum, Egypt
Authors: Rahman Abu Hamed Abdel , Sannen A. M. H. 
Published: May 2018

The paper provides a case study of rural water supply in Fayoum. First, the present state-of-affairs is described and analyzed with respect to production, consumption and coverage. A water balance is drawn up and the projected trends up to the year 2000 are indicated. Nearly full coverage has been achieved already but still more than 50% of the population is served by public standposts. Considerable demand for house connections is apparent. Based on the present trend it is expected that by the year 2000, 75% of the population could be served by private connections, provided sufficient production capacity becomes available.
Secondly, the focus is on organization and finance with special attention to cost recovery. Estimates for present billing efficiency and the Unaccounted For Water (UFW) percentages are provided. With the perceived trend in the growth of house connections and decline of public taps there is ample potential to reduce UFW, provided an efficient billing and fee collection system is introduced and leakage is controlled. With the reduction of UFW by “technical” measures half of the cost recovery target can be achieved. The other half has to come from tariff increases.
Experience is drawn from the Netherlands-supported Fayoum Drinking Water and Sanitation Project (FADWS) which started in 1990.
Assessment of the Performance of Oxidation Pond System for Wastewater Reuse
Authors: El-Gohary F. , Abdel Wahaab R. , El-Hawary S. , Shehata S. , Badr S. , Shalaby S. 
Published: May 2018

A study has been conducted to evaluate the performance of an aerated oxidation pond system in a village in Egypt. It comprises an anaerobic pond (AP), an aerated facultative pond (AeP) and a maturation pond (MP). The assessment involved an intensive programme of sampling and analysis of raw wastewater, unit process contents and unit process effluents.
Field studies indicated a wide fluctuation in the BOD5 load applied to the STP. It ranged from 64 to 290 g BOD5/m3.d, with an average value of 146 g BOD5/m3.d. This, however, did not affect physico-chemical characteristics of the final effluent. Residual COD, BOD & SS were around 99 mg/l, 32 mg/l & 66 mg/l, respectively. Although faecal coliform removal was around 98.9%, yet residual count was still high. Also, significant decline in both parasitic eggs and protozoal stages has been recorded.
Impact of the Reuse of Domestic Waste Water for Irrigation on Ground Water Quality
Authors: Farid M. Samir M. , Atta Samir , Rashid Mohamed , Oude Munnink Josefien , Platenburg Ruud 
Published: May 2018

Egypt planned to reclaim large areas in both the Eastern and Western desert fringes of the Nile Delta with an increasing use of sewage effluent from Greater Cairo. The Gabal el Asfar farm which has been irrigated with raw to primary treated sewage effluent for a period of seventy five years was selected as a pilot area to investigate the groundwater quality. This farm covering 3000 feddan (1250 ha), is located in the sandy area northeast of Cairo.
The main objective of the study was to assess the impact of agricultural application of sewage effluent on groundwater quality. Observation wells were constructed and field and laboratory measurements were carried out in and around the Gabal el Asfar area. The water balance and mass balances have been assessed. The study yielded useful recommendations to decrease the impact on groundwater quality and possible risks in Gabal el Asfar, concerning 1) type and amount of pollution from sewage effluent, 2) design criteria to control possible spreading of pollutants, and finally 3) the use of groundwater in the area. The following comprises the main conclusions:*Irrigation with sewage effluent had a positive impact on salinity of the initially brackish groundwater. On the contrary, groundwater quality is negatively affected from sewage effluent with regard to nitrogen contents (ammonium and nitrate), phosphate, heavy metals and faecal coliforms.*The drinking water limit for nitrate is sometimes exceeded. Moreover, faecal coliforms are found in water from all shallow handpumps in the area. The general suitability of the groundwater is therefore limited while the use of handpumps for drinking water purposes should be avoided. High boron contents of sewage effluent indicate a risk for crops sensitive to boron.*The accumulation of heavy metals and phosphorus in the soil adversely affects the soil system.*Pretreatment of sewage effluent in Gabal el Asfar should be improved to limit the pollution of the aquifer. Industrial discharge in sewage effluent should be avoided.*Groundwater recharged by sewage effluent is mainly collected by drains in or at the borders of the area, so spreading of pollutants out of the area is largely controlled.
Wastewater Treatment over Sand Columns – Treatment Yields, Localisation of the Biomass and Gas Renewal
Authors: Guilloteau J. A. , Lesavre J. , Liénard A. , Genty P. 
Published: May 2018

Domestic wastewater treatment by infiltration-percolation is a process that is becoming common in France. The aim of this study is to find the depth of biologically active substrate in an infiltration basin by determining the depth of the media colonised by the biomass and by studying oxygen renewal mechanisms. The study using sand columns has allowed simultaneous comparison, on the same profile, of biomass content (ATP), gaseous composition (chromatography) and the variations of the effluent quality (carbon, nitrogen, phosphorus). Down to a depth of 30 cm, removal rates achieved in terms of conventional treatment parameters are very high (COD and SS &gt; 90%, NH4+ ≈ 95%, total phosphorus ≈ 50%). Beyond a depth of 15 cm, the biomass content (expressed in ATP) is ten times less than at the surface, and virtually ceases to develop.
Monitoring of O2 levels points to the need for drying periods in order to ensure natural ventilation of the basins. The primary settling stage must be effective in order to avoid any risk of clogging which would prevent the air from being renewed by diffusion.The length of the drying period must be almost double that of the flooding period to allow the media to recover as much of its treatment capacity as possible.
This study pinpointed the depth of the biologically active substrate at arround 30 cm. The data obtained from this trial project point to the following design criteria: 1.5 m2/p.e. spread over three basins, and a drying period twice as long as the flooding period. The sand depth will depend on the plant's overall water quality objectives: around 0.50 m for the removal of carbonaceous pollution and nitrification of Kjeldahl nitrogen, a greater depth for disinfection purposes.
Coupling of Reed Bed Filters and Ponds: An Example in France
Authors: Liénard A. , Boutin C. , Bois R. 
Published: May 2018

The study of wastewater treatment series based on the use of macrophyte beds, in accordance with a design initially developed in Germany by Dr. Seidel, was initiated by CEMAGREF in 1983. The number of plants constructed was deliberately limited and they were subject to regular assessments and improvements. It was thus shown that only reed bed filters that were drained and alternately fed, were able to handle a pollutant load of the order of 80 g COD m-2 day-1 with satisfactory treatment reliability over a period of several years. The Gensac la Pallue plant, in the Charente department, is original since it combines this type of filter in the first treatment stage with three microphyte ponds designed with a low theoretical residence time of 21 days (compared with the usual residence time of 30 days in tertiary treatment). The whole treatment series only occupies an effective surface area of approximately 6 m2 per p.e. (about 1 m2 and 5 m2 for filters and ponds respectively).
After 5 years of operation and monitoring, it has been clearly established that filters dosed with raw wastewater at a rate of 65 g of COD and 30g of TSSm-3 per day, regularly achieve a removal rate of 70 to 85 % of these same elements without clogging. The daily hydraulic load that the filter can withstand in service regularly exceeded 2 metres in the month of November 1992.
The ponds finish the treatment and this article limits itself to analysing results relating to the elimination of nutrient, which reaches 35% for nitrogen and 55% for phosphorus. Residence times that are too short in winter, in conjunction with a large part of the sewerage system being of combined type, can sometimes temporarily lead to an increase in the amounts of nitrogen and phosphorus discharged to the natural environment.
Preformed Ferric Hydroxide Flocs as Adsorbents of Humic Substances
Authors: Cathalifaud G. , Wais Mossa M. T. , Mazet M. 
Published: May 2018

The purpose of this study is to show that previously built flocs obtained by the coagulation-flocculation of kaolinite suspension with ferric chloride are a potential adsorbent of humic substances.
Flocs are prepared from kaolinite (&lt; 50 µm) and FeCl3 according to the jar-test technique:after 3 minutes of rapid mixing at pH = 5.4 ± 0.1, 30 minutes of slow mixing, humic acids are added for a contact time of 6 hours; the effects of calcium, sodium salts (chloride, sulphate) on the adsorptive capacity of preformed flocs are also studied. The results indicate that the preformed flocs are good adsorbent materials. Langmuir equation is used to determine adsorption capacities.
Improving Municipal Waste Water Quality by Effluent Polishing: A Pilot Scale Experiment at Winterswijk, The Netherlands
Authors: Oesterholt F. I. H. M. , Bult B. A. 
Published: May 2018

Over a period of three months two filtration methods, i.e. cross flow microfiltration and continuous sand filtrations were tested for their capacity to improve the quality of the effluent from a waste water treatment plant. The removal capacity of both methods was explored for suspended solids, COD, Kjeldahl nitrogen phosphorus, copper and zinc with and without iron flocculation. Without iron flocculation only the suspended solids can be removed. Iron has to be added prior to removal so that suspended solids and phosphorus can be removed in sufficient quantities. In that case, total P can be removed for 70% by means of continuous sand filtration, and for 90 % when microfiltration is being applied. The removal of COD, nitrogen Kjeldahl, copper and zinc is confined to 10 or 20%.
From a technical point of view, microfiltration is preferred because of its high removal efficiency for all the components. On the other hand, from a financial point of view, microfiltration is not feasible. Treatment costs for sand filtration and microfiltration are calculated at f 0.15 and f 2.07 respectively per m3 water treated.
A Strategy to Meet the Nutrient (N and P) Standards of the Urban Wastewater Directive
Authors: Farrimond M. , Upton John 
Published: May 2018

The implications for the UK of the forthcoming Urban WasteWater Directive 1991 will mean at many sites a tightening of existing discharge standards. At those sites classified as discharging to sensitive watercourses, limits for nutrient removal (N and P) will be imposed and for the largest works above 100,000 PE implementation is required by 1998.
Very little experience of N and P removal currently exists in the UK and water companies will need to develop the necessary investment strategies based for the most part on retrofitting well proven technologies to existing secondary treatment works.
A strategy has been developed for nutrient removal in Severn Trent Hater, a company which serves a sewered population of 8 million and controls 1043 waste water treatment plants.
The paper outlines the technologies that will be retrofitted to existing trickling filter installations and activated sludge plants to achieve the necessary standards for N and P removal.
A comparison of the various options for biological P removal is included and that the preferred UCT process configuration or sidestream Phostrip process have been selected as preferred options.
Thermic Sludge Treatment
Authors: Karlsson I. , Göransson J. 
Published: May 2018

Chemical pretreatment changes the composition of waste water by reducing the paniculate organic matter.
A lower biological sludge production from the sewage facilitates nitrification.
The denitrification capacity of the sewage is decreased, but the fraction of low molecular substances is not influenced by the chemical treatment.
To increase the denitrification capacity, the organic matter removed can be hydrolised into a readily degradable form and used as an electron donor. In Tampere waste water plant the sludge is hydrolysed at 150° C in a low pH environment.
The carbon source was increasing the capacity of the anoxic zone.
The sludge dewatering characteristics were improved.
The sludge is divided into two fractions, one with paniculate organic matter, the other containing a solution of organic and inorganic substances. The heavy metals can be separated and the precipitant recovered and recycled.