1,720,979 research outputs found
Pharmaceutical compounds in waters. Investigations on hospital effluents as a source of environmental contamination and on their treatability
No full textThe activity research done during this Ph.D., was born as an overview of pharmaceutical
compounds (PhCs) in wastewaters (WWs). In particular, the aim of this work was evaluate
the occurrence of these emerging pollutants in the hospital’s wastewaters (HWWs), considered
one of the main sources of these contaminants in the public sewage and in the environment.
To do this, many water samples (withdrawn from different kind of waters: groundwaters,
surface waters, drinking waters, urban wastewaters, hospital wastewaters, bottle waters) were
analysed in order to investigate the problem and have more data to compare HWWs with urban
ones. The chemical’s analysis includes conventional macropollutants like BOD5, COD, SS, N
compounds. . . as well as pharmaceuticals (till 73 compounds were monitored).
Chapter 2 of the thesis, explains the diffusion of PhCs into the environment. It starts from a
literature’s basis that explains the occurrence, fate of PhCs, the health risk and the consequent
ecotoxicological effects; the experimental investigation regards different samples taken from
surface waters of Po River, groundwaters (GW) from the first aquifer below the Po River and
drinking waters (DW) at different steps of the Ferrara’s waters work. The aim of this chapter
is investigate the occurrence of PhCs in the environment (by comparing our conclusions to
the literature results) and verify if the treatments adopted at water works of Ferrara, could
guarantee a sufficient removal of the investigated compounds.
Chapter 3 represents the central chapter (the core chapter) of this work. It refers to hospital
and urban effluents, it compares these two kinds ofWWs in terms of flow rates and concentration
and loads of conventional macroparameters (mainly BOD5, COD, SS). All these treated aspects
are about the basis of literature and they compare them data with the data that we will find in
our experimental investigations. The final part of the chapter show the analytical results done
on PhCs in two real hospital effluents that have been studied (Lagosanto and Ferrara). In this
chapter are also analysed the different water consumption in the hospital structures because
for a single user (the typical user in the hospital is normally the patient, expressed in terms of
bed) the water consumption is really different from the usual inhabitant equivalent.
Chapter 4 explains all the experimental investigation carried out in these research years.
The chapter is divided in 6 sections. Each section takes in consideration a different experimental
investigation.
The first section regards the raw hospital effluents disinfection. This kind of treatment
should not be the only and the first one but in some developing countries, where WWTPs are
not presents, hospital’s effluents should be at least pre-treated by sedimentation and disinfection
before they will be discharged into the environment. The aim of the research was evaluate the
correct dose of disinfectant (peracetic acid or hypochlorite) used for direct discharge of raw
effluent into the environment, in order to avoid health and environmental risks.
The second experimental campaign was about the treatment of the raw hospital effluent
of Lagosanto (near Ferrara, 300 beds) where two different MBR pilot plants (with equipped
microfiltration and ultrafiltration membranes) were tested by analysing macroparameters and
some PhCs. This experimental section had the purpose to compare the MBR performance with
the CAS, one with respect to macro and micro parameters.
Also the experimental campaign performed in La Spezia WWTP (north west of Italy)
compared the difference between conventional treatments (CAS) and MBR performances, but
in this case, the feed to the plant was the UWWs. In the final part of this investigation was
also tested a final treatment with ozone.
A further investigation was done at Ferrara’s WWTP, in order to evaluate the contribution
in the removal of 73 PhCs by a CAS and a polishing treatment, that consist in a horizontal
subsurface flow system. During this investigation in Ferrara’s WWTP, two different study
steps were developed. The first one using the effluent of the WWTP as influent of the CW, in
order to evaluate the final efficiency by removing the 73 studied compounds. The second one
add a mixture solution of Ciprofloxacin, Sulphametoxazole and Trimethoprin at the influent
of the natural system, with the aim of verify the efficiency of the natural treatment with high
concentration of the spiked compounds.
The final section of this chapter discusses and compares the different tested technologies,
with particular attention to the natural systems and to the concept of the multibarrier system
able to remove a great number of PhCs from WWs.
Chapter 5 is mainly focused on the different technologies that are able to remove the PhCs on
the basis of a deeper literature’s research. The chapter deals the physico-chemical treatments,
the conventional and advanced biological treatments, the nanofiltration technology, the reverse
osmosis, the chlorination, a rapid overview about ozonation and AOPs treatment, the natural
polishing treatment and, to conclude, the photodegradation. In the last part, the chapter
presents and deals the treatment sequence adopted on the effluent of the new hospital under
construction near Ferrara (900 beds)
Treatment and treatability of hospital wastewaters.
No full textIn the last years, increasing attention has been paid to the presence of emerging pollutants in wastewaters, surface waters and groundwaters (Daughton and Ternes, 1999; Heberer 2002, Barcelò 2003, Daughton 2004).
Emerging contaminants correspond in most cases to unregulated pollutants, which may be candidate for future regulation depending on research on their potential health effects and monitoring data regarding their occurrence. They include surfactants, pharmaceuticals and personal care products (PPCPs), endocrine disruptors, illicit drugs, gasoline additive....
Referring to pharmaceuticals, large amounts of different compounds are used worldwide and, in the last decade, their sales are continuously increasing (Kummerer, 2001; Ternes and Joss, 2006). After administration, the active substances of medicaments are metabolized, but only to some extent. The unmetabolized active substances are excreted in urine and faecis as unchanged substances, as a mixture of metabolites or conjugated with an inactivating compound attached to the molecule (Halling-Sorensen et al., 1998), thus entering in the water cycle.
Hospitals are important sources for these compounds, but not unique. Residues of pharmaceuticals can be found in all wastewater treatment plant (WWTP) effluents, due to their inefficient removal in the conventional systems (Kummerer, 2001, Petrovic et al., 2003; Carballa et al., 2004, Onesios et al., 2009).
A great variety of microcontaminants are present in hospital effluents resulting from diagnosis, laboratory and research activities from one side and medicine excretion by patients from the other side. They include active principles of drugs and their metabolites, chemicals, heavy metals, disinfectants and sterilizants, specific detergents for endoscopes and other instruments, radioactive markers, iodinated constrast media, ...
Despite their specific nature, quite often, hospital effluents are considered of the same pollutant load of urban wastewaters (UWWs), so they are discharged into the sewer network, collected to a WWTP and cotreated with UWWs.
Before immission into the municipal sewer, a chlorination is sometimes required for the whole hospital wastewater (HWWs) flow rate, sometimes only for the effluent from infectious disease wards (Emmanuel et al., 2003).
The common practice of cotreatment of hospital and urban wastewaters at a municipal WWTP is not considerated an adequate solution by many Authors (among them Altin et al, 2003, Pauwels et al., 2006, Vieno et al., 2007) because it is based on dilution of different discharges and it does not provide a segregation/separation of pollutants, in particular of emerging contaminants and toxic substances from the liquid phase which than is discharged into the environment.
The difficulties in removing micropollutants, in particular pharmaceuticals, from wastewaters are due to the fact that their concentrations are in the range 10-3-10-6 mg L-1, lesser than those of conventional macropollutants (BOD5, COD, nitrogen and phosphorus compounds...). Moreover, they include a broad spectrum of compounds with great differences in the main properties which affect their behaviour and fate in the WWTP: solubility, volatility, adsorbibility, absorbibility, biodegradability, polarity and stability.
Municipal WWTPs were first built, then upgraded, with the principal aim of removing carbon, nitrogen and phosphorus compounds, as well as microbiological organisms: pollutants which regularly arrive at the WWTP in concentrations of the order of mg/L and at least 106 MPN/100 mL. Conventional treatments are not able to greatly remove also microcontaminants.
Moreover, HWW flow rates generally amount to only a small percentage of the total influent flow rate for co-treatment at a municipal WWTP. Consequently, dilution of HWWs with UWws will result in a decrement of the PhCs content in the final effluent (from mg L-1 to ng L-1), but not in their load, that is, the quantity released daily into the receiving water body.
In this paper, a comparison between quali-quantitative characteristics of hospital and urban wastewaters is carried out, based on an in-depth literature review.
First water consumptions and wastewater production variation along the year are discussed for hospitals and urban settlements. Then chemical and physical characteristics of HWWs and UWWs are analized in terms of conventional macropollutants (BOD5, COD, SS, nitrogen and phosphorus compounds, E. coli,... ) as well as micropollutants (main pharmaceuticals, detergents, disinfectants).
An overview of the sustainable treatment options for HWWs is presented and finally the main outlines of a study carried out on the characteristics and adequate treatments of HWWs are reported. In particular the management of the effluent in a specific case study at the large hospital complex (900 beds), near Ferrara, Northern Italy, is examined through an evaluation and comparison of the design alternatives for its treatment and the main outlines of the final approved project are presented
New receiving water body foe a large WWTP in a sensitive area in Northern Italy: refitting with natural systems and water reuse
No full textRemoval and accumulation of Cu, Ni and Zn in horizontal subsurface flow constructed wetlands: contribution of vegetation and filling medium
No full textThis study investigated the accumulation and removal of Cu, Ni and Zn in two horizontal subsurface flow constructed wetlands for domestic wastewater treatment, which differ by shape, presence of macrophytes and water depth. Between March and December 2007, the three metals were measured in the influent and effluents of the two systems. Average percentage removal rates were extremely low for Cu (3 % and 9 % in the two beds) and higher for Zn and Ni (between 25 and 35 %). Under higher Zn influent concentrations, it was found to be between 78-87 %, which is in agreement with other literature data.
During the peak standing crop season (August), biomasses of the different parts of Phragmites australis (stems, leaves and flowers, roots and rhizomes) were analysed in terms of weight and heavy metals concentration in order to assess heavy metals distribution among the tissues. It was found that the plants contribute to total heavy metals removal to a lesser extent than the filling medium. Aboveground tissues remove 34 % of Cu, 1.8 % of Ni and 6.2 % of Zn % and, once harvested, their disposal does not appear to pose a problem for the environment. If heavy metals are present at high concentrations in the horizontal subsurface flow bed influent, over time, their accumulation in the filling medium could necessitate special care in the bed’s management to avoid release into the surrounding environment
Management of Hospital Wastewaters: the Case of the Effluent of a Large Hospital Situated in a Small Town
No full textHospitals are the main source of pharmaceutical compounds (PhCs) released into the environment. Generally, their discharges are co-treated with domestic wastewaters, resulting in a decrement of the recalcitrant compounds concentrations in the final effluent due to water dilution. However, as many PhCs resist normal treatments, pollutant load does not change. This paper compares the chemical characteristics of hospital and domestic wastewaters (in terms of macro-pollutants as well as main PhCs) on the basis of an experimental investigation and literature data. A membrane biological reactor pilot plant fed by a hospital effluent is tested in order to evaluate the feasibility of treating these kinds of wastewaters with membrane systems. The paper then presents the possible scenarios in the management of the effluent of a large hospital situated in a small town. In particular, it reports on a case study of designing a (new) treatment plant for the effluent of the 900 bed hospital in Ferrara, Northern Italy, located in the outskirts of the town, Finally, costs for the intervention are given
Management of the effluent of a large hospital situated in a small town. A case study
No full textHospitals are the main source of pharmaceutical compounds (PhCs) released into the environment. Generally, their discharges are co-treated with domestic wastewaters, resulting in a decrement of the recalcitrant compounds concentrations in the final effluent due to water dilution. However, as many PhCs resist normal treatments, pollutant load does not change. This paper compares the chemical characteristics of hospital and domestic wastewaters (macro-pollutants as well as main PhCs) on the basis of an in-depth literature review. It then discusses the most adequate treatments for hospital discharges and in particular reports the case study for designing a (new) treatment plant for the effluent of the large hospital in Ferrara (900 beds), located in the first outskirts of the town, in a small urban and industrial centre of about 2000 inhabitant equivalents. Design options (dedicated treatment or co-treatment) are compared, adopted sequence of treatments is discussed and costs for the intervention are given
A PROMISING PRACTICE TO RECLAIM TREATED WASTEWATER FOR REUSE: CHEMICAL DISINFECTION FOLLOWED BY NATURAL SYSTEMS
No full textThe availability of freshwater to meet different water needs has raised serious concerns in the last decades all around the world. Water scarcity, deterioration of quality and increasing demand have led to the development and use of alternative sources of water. Reclamation and recycling are now considered as key components of water and wastewater management policies around the world. In this context, the adoption of soft wastewater treatments with a minimum use of chemical agents and having minimum environmental impact is widely encouraged.
An experimental campaign was carried out on a pilot plant which consisted of a two-stage disinfection system for a secondary biological effluent. Disinfection consisting of a chemical step (mild chlorination) followed by a natural one (filtration through a horizontal subsurface flow (HSF) bed) was tested in order to evaluate the possibility of producing a final effluent adequate for agricultural reuse.
The investigation has shown that this combined system, with low doses of NaClO (2 mg L-1 of disinfectant and a retention time of 30 minutes, corresponding to an applied dose of 2 x 30 = 60 mg L-1 min-1) and a well designed final subsurface flow system (at least 1 m2 EI-1) is able to obtain an effluent complying with reuse quality limits, in particular for microbiological parameters.
For HSF design parameters, neither filling material, aspect ratio nor vegetation type (Phragmites australis and turf) caused significant differences in the average levels of COD, suspended solids, NH4, total phosphorus and Escherichia coli concentrations in the effluent.
Finally in order to protect HSF bed from substrate clogging and prolong its working life, a rapid sand filter was placed before the bed and its impact analyzed. It was demonstrated that the filter was able to retain occasional but unavoidable activated sludge carry-overs from the secondary clarifier which otherwise would rapidly accumulate in the front region of the bed resulting in poor performance (overflows and medium clogging) in quite short time
Wastewater Polishing Index: a tool for a rapid quality assessment of reclaimed wastewater
No full textA new index, the Wastewater Polishing Index (WW.P.I.), has been defined for the rapid assessment of the quality achieved by different polishing treatments for water discharged into surface water bodies and for reuse purposes. The index is defined by a weighted average of six parameters (SS, BOD5 COD, ammonia, total phosphorus and E. coli), each transformed onto a sub-index scaled from 0 to 100. E. coli has been assigned a greater weight than the other indicators. The index is equal to 0 if none of the six pollutants are present in the effluent and to 100 when all six parameters equal their corresponding Italian legal limits for discharge into surface water bodies. When all 6 of them equal their corresponding Italian legal limits for reuse, the WW.P.I. is 36.
The index has been validated and tested on a pilot plant including a rapid sand filtration, a slow filtration through a horizontal subsurface flow system and a lagooning, in addition to their combinations. The experimental investigation showed that the index is a good tool for (i) rapidly comparing the water quality achieved by different treatment sequences, particularly natural systems; (ii) rapidly evaluating whether the proposed sequence is able to produce an effluent adequate for reuse and (iii) rapidly evaluating the water quality improvement achieved by different systems.
The proposed index could be of great help for managers and decision makers when planning for water resources, in particular, for comparing the quality level achieved by different wastewater treatment sequences
Caratterizzazione e trattabilità di reflui ospedalieri: indagine sperimentale (con sistemi MBR) presso un ospedale dell’area ferrarese
No full textLo studio si riferisce ad una ricerca in corso presso il Dipartimento di Ingegneria di Ferrara, in collaborazione con Ato6, USL, CADF ed Hera Ferrara relativamente alla trattabilità e ai trattamenti più adeguati dei reflui ospedalieri. L’indagine, condotta sull’effluente dell’ospedale Delta (300 posti letto) di Lagosanto (Fe), ha riguardato (i) dapprima la caratterizzazione quali-quantitative del refluo prima dell’immissione in pubblica fognatura al fine di individuare gli inquinanti più rappresentativi (che sono risultati essere antibiotici e un antiepilettico); (ii) poi una sperimentazione su impianti pilota per valutare l’efficienza di rimozione di sistemi biologici a membrane (piane e a fibra cava) e sistemi convenzionali. Sulla base delle risultanze sperimentali e della più recente bibliografia al riguardo, si propongono delle indicazioni relativamente al trattamento dedicato più appropriato per il refluo ospedaliero. Tali indicazioni rappresentano il punto di partenza per le scelte progettuali per la realizzazione dell’impianto di trattamento delle acque reflue del nuovo sito ospedaliero della città di Ferrara (900 posti letto)
A Promising Practice in Disinfection Treatment for Reuse: Chemical plus Natural Systems,
No full textAn experimental campaign has been conducted on a pilot plant which consists of a two-stage disinfection system for a secondary effluent: a chemical treatment, by means of low dosages of NaClO, followed by a natural one, in a horizontal subsurface flow bed. The aim is to analyse, during a hot period, the microrganisms removal achievable by the two stages and to compare the polished effluent quality with the Italian severe law limits for agricultural reuse of reclaimed wastewaters.
The investigations has shown that in presence of high ambient temperatures, just a well designed final subsurface flow system is able to respect reuse quality limits. In this case, for safety reasons, a further UV treatment, after the only natural step, may be suggested, as it may prudentially switch on, only in case of emergencies that may occasionally occur
- …
