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This paper reports a monitoring and modeling of the occurrence of metals in a WWTP inflow, identifying the different sources of metals in domestic, commercial/industrial wastewater and surface runo...

Municipal wastewaters may pose a risk to the aquatic environment and ultimately to human kind. Their treatment is a fundament step but the actual WWTPs performances cannot be taken for granted, claiming instead for continuous evaluation campaigns. Our waters are indeed threatened by the continuous input of various persistent micropollutants that are part of human daily routine life; the potential effects of their presence in the receiving waters have to be quantified. The present paper reports data of a monitoring campaign focused on nine pharmaceuticals belonging to different therapeutic groups in three WWTPs in Tuscany (Italy). All the three WWTPs use conventional activated sludge process with pre-denitrification and no tertiary treatment. The analytical determination has been achieved through off-line solid phase extraction and analysis in liquid chromatography coupled with mass spectrometry. The overall ecotoxicological effect of effluents was evaluated through a battery of tests using organisms belonging to different trophic levels. All nine pharmaceuticals were detected in the influent of all WWTPs at least in one sampling campaign. The most concentrated compounds were acetaminophen, diclofenac and amoxicillin followed by atenolol, ketoprofen, clarithromycin, carbamazepine, doxycycline and E2; their average concentrations (considering all measurements from all plants) were, respectively: 3914 ± 2620; 2065 ± 739; 2002 ± 2170; 1223 ± 1042; 961 ± 1003; 356 ± 370; 233 ± 100; 196 ± 189; 4 ± 4 ng/L. The highest concentrations were found in the plant that treats urban and hospital wastewaters. Amoxicillin, atenolol and diclofenac were more concentrated in winter than in summer, while ketoprofen, doxycycline and 17-β-estradiol are higher in summer. These results are probably due to the different consumption of each drug during the year, depending on their therapeutic usage. Measured drugs can be divided into three categories: those ones that are generally well removed inside the WWTP (such as acetaminophen, ketoprofen and atenolol), the partly removed ones (doxycycline, clarithromycin and 17-β-estradiol) and the refractory ones to biodegradation during activated sludge process (carbamazepine, diclofenac and amoxicillin). Regarding ecotoxicological assays, the most sensitive organisms were V. fisheri and R. subcapitata, whereas D. magna almost never reacted to the wastewaters. Seasonal variability was not clearly observed among plants and collecting time. The toxicity score evaluated all the results coming from the bioassays battery, indicating that WWTPs treatments always determined a toxicity reduction, even though a residual toxicity was still measured. This observation, together with chemical data, clearly indicate WWTPs as an important source of pharmaceuticals in the Arno river with an important environmental toxicity; therefore, the reduction of pharmaceutical load originated from point source such us WWTPs would ask in the future the adoption of refinery steps in WWTPs able to increase RE of drugs.

In this paper, the design and start-up of a constructed wetland (CW) for the tertiary treatment of landfill leachates is presented. The flux is characterized by high salinity, high concentration of nitrogen (almost completely in the form of nitrate) and a biochemical oxygen demand (BOD)/chemical oxygen demand (COD) ratio close to zero. The CW pilot plant suffered from mechanical and hydraulic malfunctions which led to an uneven growth of plants inside the tanks. Despite this, COD has been reduced in the range of 0–30%, reduced forms of N (ammonia and nitrite) are also oxidized and removed by 50–80% and 20–26% on average. Considering the low number of plants and the loading rate, CW pilot plant allowed to remove more than 16 kg of COD, leading to a specific removal of 10 gCOD/d · m2. Moreover, bacterial communities associated to plants were isolated and analyzed in order to evaluate the influence of such communities on phytoremediation. Bulk soil registered the lowest bacterial titers, while plant compartments and rhizospheric soil showed to be more suitable for bacterial colonization. Twenty-five different bacterial genera were observed among the analyzed isolates, with the predominance of Pseudomonas genus.

A two-stage biological process using fungi and bacteria was set-up and tested for treating a petrochemical wastewater containing naphthalene sulphonic acid polymers. The fungal treatment was carried out through a trickling filter inoculated with

The objective of this paper is to find the optimum solid retention time (SRT) of a wastewater treatment plant (WWTP), which minimizes operating costs, using a modeling approach with WEST software by MIKE DHI®. For the determination of the kinetic and stoichiometric parameters (used for the correct calibration of the model implemented), respirometric and kinetic batch tests were carried out. Each Oxidation ditch was modeled by a sequence of four aerated activated sludge units (ASUs) and four anoxic ASUs with recirculation. The model is able to simulate the separation efficiency of the secondary settler, which is generally quite low: in fact, the industrial origin of the wastewater induces the formation of small flocs, the dimensions of which can be further reduced by the presence of surface aerators. The nitrification/denitrification process is also accurately predicted. Using data obtained from the model, mass balances at the steady state for COD and N were made and compared to the ones obtained using measured data. After calibration and validation of the model, steady-state simulations were carried out by increasing and decreasing the SRT of the system under two different operational conditions used by the managing company and by evaluating the costs related to the water treatment line and the sludge treatment line for each scenario. It is interesting to note how the total costs are lower in summer than in winter (7.2 €cent/m3 in summer and 8.7 €cent/m3 in winter, in scenario 0). In general, the increase in the SRT led to a decrease in the total management costs. In fact, differences between scenario 0 and the scenario with the lowest total treatment costs (corresponding to an SRT of 11.4 d in winter and 10.0 d in summer) could give rise to total savings of about 44·000€/year in summer and 93·000€/year in winter.

This paper presents a case study describing a full-scale membrane bioreactor (MBR) for the pretreatment of landfill leachates. The treatment train includes an aerated equalization tank, a denitrification tank, an oxidation/nitrification tank, and two ultrafiltration units. The plant has worked continuously since 2008 treating landfill leachates at a flux of 2&ndash, 11 L&middot, h&minus, 1&middot, m&minus, 2. The old train of membranes worked in these conditions for more than seven years prior to being damaged and replaced. The permeability (K) of the membrane varied between 30 and 80 L&middot, 2&middot, bar&minus, 1 during the years of operation. In 2010, after two years of operation, the oxidation/nitrification tank was changed to work in alternate cycles of aerated and anoxic conditions, in order to improve the denitrification process. The MBR, working at a mean sludge retention time of 144 days and with mixed liquor suspended solids of 17 g/L, achieved high removal rates of conventional contaminants, with more than 98% for Biochemical Oxygen Demand, 96% for ammonium, and 75% for Chemical Oxygen Demand (COD). From the COD balance, half the COD entering was determined to be biologically oxidized into carbon dioxide, while another 24% remains in the sludge. In order to obtain these results, the company used 5.2 KWh&middot, 3, while spending 0.79 &euro, &middot, 3.

The fungus Pleurotus ostreatus was investigated to assess its ability to remove diclofenac, ketoprofen, and atenolol spiked at 10 mg/L each one in hospital wastewater. The degradation test was carried out in a fluidized bed bioreactor testing both the batch and the continuous mode (hydraulic retention time in the range 1.63-3 days). In batch mode, diclofenac disappeared in less than 24 h, ketoprofen was degraded up to almost 50% in 5 days while atenolol was not removed. In continuous mode, diclofenac and ketoprofen removals were about 100% and 70% respectively; atenolol degradation was negligible during the first 20 days but it increased up to 60% after a peak of laccase production and notable biomass growth. In order to identify the enzymatic system involved, further experiments were carried out in flasks. Purified laccase completely transformed atenolol and diclofenac in less than 5 h, but not ketoprofen. In vivo experiments suggested that cytochrome P450 could be involved in diclofenac and ketoprofen degradation, while partial correlation studies confirmed the role of laccase in atenolol and diclofenac degradation. Two intermediates of diclofenac and ketoprofen were detected by nuclear magnetic resonance. Moreover P. ostreatus was able to reduce chemical oxygen demand of the hospital wastewater which is an important advantage comparing to other fungi in order to develop a wastewater treatment process. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1529-1537, 2017.

The ability of the white rot fungus Pleurotus ostreatus to biodegrade 2-naphthalenesulfonic acid polymers (2-NSAP) contained in a petrochemical wastewater was evaluated. The characterization of the wastewater and a LC–MS identification of polymers were performed. Biodegradation experiment was conducted in batches with and without the addition of a carbon source (glucose, corn starch, cellulose and lignin). It has been demonstrated that, in presence of a suitable carbon source, P. ostreatus is able to remove NSAP ranging from trimers to decamers. Interestingly, all the carbon sources utilized, despite the different velocities, allowed to degrade about 60–70% of the oligomers. Furthermore, respirometric tests showed that the fungal treatment was also able to significantly increase the bCOD/COD ratio, going from 9% (raw wastewater) up to 57%. This is clearly correlated with the enhancement in oligomers depolymerization confirming that the fungal action is not a mineralization of NSAP, but an increase of their biodegradability.

A monitoring on the occurrence of nine different pharmaceutical active compounds at the inlet and outlet of three wastewater treatment plants in Tuscany has been made. Moreover, the overall toxicity of the wastewater was evaluated using two different bioassays.

This paper presents a first scale up under non-sterile conditions of the biodegradation process of 2-naphthalensulfonic acid polymers (NSAP) contained in a petrochemical wastewater by two white-rot fungi (Bjerkandera adusta and Pleurotus ostreatus). The biodegradation experiment was conducted first in flasks and then in packed-bed bioreactors filled with inert and biodegradable carriers (straw), the latter acting as both physical support and carbon source. Reactor inoculated with P. ostreatus attached on straw worked under non-sterile conditions for three months showing 30 ± 5% NSAP degradation. Respirometric tests showed that the fungal treatment was also able to significantly increase the biodegradable fraction of the wastewater COD, which rose from 9% to 40%. It was observed that the fungal degradation of the straw in the bed releases non-biodegradable by-products. Taking into account this contribution to nbCOD, the combined treatment of fungi and activated sludge could theoretically be able to reduce the original COD by up to 73%.