Remediation in situ of hydrocarbons by combined treatment in a contaminated alluvial soil due to an accidental spill of LNAPL

4noThe soil contamination represents an environmental issue which has become extremely important in the last decades due to the diffusion of industrial activities. Accidents during transport of dangerous materials and fuels may cause severe pollution. The present paper describes the criteria of the actions which were operated to remediate the potential risk and observed negative effects on groundwater and soil originated by an accidental spill of diesel fuel from a tank truck. With the aim to evaluate the quality of the involved environmental matrices in the “emergency” phase and in the following “safety” operation a specific survey on hydrocarbons, light and heavy, was carried out in the sand deposits soil. Elaboration of collected data allows to observe the movement of pollutants in the unsataturated soil. The remediation action was finalized to improve the groundwater and soil quality. The first was treated by a so called “pump & treat” system coupled with air sparging. A train of three different technologies was applied to the unsaturated soil in a sequential process: soil vapour extraction, bioventing and enhanced bioremediation. Results showed that the application of sequential remediation treatments allowed to obtain a state of quality in groundwater and soil as required by Italian law.nonemixedTrulli, Ettore; Morosini, Cristiana; Rada, Elena Cristina; Torretta, VincenzoTrulli, Ettore; Morosini, Cristiana; Rada, Elena Cristina; Torretta, Vincenz

Pharmaceuticals in water cycle: a review on risk assessment and wastewater and sludge treatment

Pharmaceuticals in the environment are considered as emerging contaminants which are particularly persistent and which could represent a threat both for animals and humans following long-term exposure. Pharmaceuticals include, among others, antibiotics, anti-inflammatory drugs, steroid hormones, antidepressants, \u3b2-blockers and lipid regulators. Excretion from humans is considered the main source of release of such compounds in the environment. The excreted compounds reach wastewater treatment plants (WWTPs), which demonstrated to be generally ineffective in removing emerging contaminants in the absence of advanced treatments. Due to the importance of the topic, which still represents an issue of great concern, this review analyses the scientific literature with the aim of investigating the role of different sources of release, the fate of pharmaceuticals in WWTPs, their typical levels in the aquatic environment, the estimated risk levels for the aquatic fauna and the potential effects on humans. In the last part of this study, different options to effectively reduce the concentrations of pharmaceuticals in effluents from WWTPs are reviewed and discussed, in order to provide environmental agencies and local administrators with an overview of the advanced treatments that are currently available to mitigate the impact of pharmaceuticals in downstream water bodies

Gestione e trattamento degli odori in Regione Lombardia: indagine su 35 impianti di depurazione delle acque reflue

Le emissioni odorigene generate dagli impianti di depurazione delle acque reflue rappresentano un problema di grande attualit\ue0, che i gestori si trovano a dover affrontare senza il supporto di una normativa nazionale che disciplini in materia. A colmare, in parte, questo vuoto, sono venute in soccorso le linee guida di Regione Lombardia e, proprio a 35 impianti ricadenti in quattro aree geografiche del territorio lombardo e appartenenti a diverse classi di potenzialit\ue0, si \ue8 rivolta l\u2019attenzione degli autori. Attraverso un questionario, infatti, sono state raccolte informazioni sui pi\uf9 diffusi accorgimenti gestionali ed impiantistici messi in atto per ovviare a tale problematica. Per ciascuna sezione, sono state riportate le misure intraprese ed i risultati conseguiti: ne \ue8 emerso come le unit\ue0 maggiormente impattanti siano i pre-trattamenti e la disidratazione e come la tecnologia pi\uf9 diffusamente implementata sia lo scrubber pluristadio, generalmente scelto per un rapporto economicit\ue0/prestazioni ritenuto vantaggioso. Al fine, inoltre, di correlare le segnalazioni dei gestori (in merito alla stagionalit\ue0 ed al momento di occorrenza, durante il giorno, degli episodi di odore) ai parametri associati alla meteo-diffusivit\ue0 dell\u2019atmosfera, \ue8 stata effettuata una simulazione modellistica, mediante CALPUFF, utilizzando i dati della stazione meteorologica di Arconate: \ue8 risultato che, mentre l\u2019alternanza giorno-notte rappresenta un elemento di fondamentale importanza nella dinamica delle concentrazioni di sostanze odorigene, la stagionalit\ue0, invece, non sembra incidere in maniera rilevante sulla stessa. Scopo del presente lavoro \ue8 quello di fornire al legislatore uno strumento a sostegno dell\u2019emanazione di specifiche linee guida (basato sullo stato dell\u2019arte esistente in buona parte del territorio lombardo), che possano supportare i gestori nel difficile processo decisionale che deve portare ad una corretta e sostenibile gestione del \u201cproblema odori\u201d

Rimozione di cromo da liquami: valutazione dell\u2019upgrading di un depuratore di reflui e rifiuti industriali

La Decisione di Esecuzione 2018/1147 prevede un nuovo e pi\uf9 restrittivo limite allo scarico per il cromo, fissato a 0,01-0,3 mg L-1; tale prescrizione, per gli impianti esistenti, dovr\ue0 essere rispettata entro quattro anni dalla sua notifica. Il presente studio si \ue8 prefisso l\u2019obiettivo di valutare, tramite lo svolgimento di Jar Test atti a testare l\u2019attuale efficienza dello stadio di chiariflocculazione, l\u2019upgrading di un impianto di depurazione di reflui e rifiuti industriali, al fine di comprendere se tale intervento possa essere sufficiente per rispettare il futuro limite normativo. Le prove svolte suggeriscono come sia essenziale un intervento di correzione delle tempistiche ad oggi adottate nel trattamento chimico-fisico, passando da 20 a 3 min per la coagulazione e da 7 a 30 min per la flocculazione. Utilizzando i reagenti normalmente impiegati nell\u2019impianto, si \ue8 riscontrato un pH ottimale, per l\u2019abbattimento del metallo, compreso nell\u2019intervallo 8,0-8,5, ed \ue8 stato dimostrato che, aumentando del 50% i dosaggi, non si verificano incrementi significativi delle efficienze di rimozione. L\u2019uso di latte di calce (attualmente non dosato), invece, ha portato ad ottenere risultati migliori a pH maggiori. Gli esiti dei Jar Test hanno inoltre evidenziato come il cromo residuo risulti trovarsi prevalentemente in forma disciolta: su questa \ue8 stato quindi valutato l\u2019effetto del trattamento biologico, la cui efficienza di abbattimento si \ue8 mediamente attestata sul 20%, presentando per\uf2 un importante range di variabilit\ue0. Infine, l\u2019adozione di un eventuale trattamento di affinamento, mediante i reagenti impiegati nell\u2019impianto, ha mostrato un\u2019ulteriore rimozione di cromo disciolto del 16-20% circa. Tutte le soluzioni individuate, tuttavia, non sono sufficienti a garantire un adeguato margine di sicurezza rispetto al nuovo limite; sar\ue0 quindi indispensabile valutare l\u2019implementazione di tecnologie specifiche per la rimozione avanzata del metallo

Improving the SoilPlusVeg model to evaluate rhizoremediation and PCB fate in contaminated soils

Tools to predict environmental fate processes during remediation of persistent organic pollutants (POPs) in soil are desperately needed since they can elucidate the overall behavior of the chemical and help to improve the remediation process. A dynamic multimedia fate model (SoilPlusVeg) was further developed and improved to account for rhizoremediation processes. The resulting model was used to predict Polychlorinated Biphenyl (PCB) fate in a highly contaminated agricultural field (1089 ng/g d.w.) treated with tall fescue (Festuca arundinacea), a promising plant species for the remediation of contaminated soils. The model simulations allowed to calculate the rhizoremediation time (about 90 years), given the available rhizoremediation half-lives and the levels and fingerprints of the PCB congeners, to reach the legal threshold, to show the relevance of the loss processes from soil (in order of importance: degradation, infiltration, volatilization, etc.) and their dependence on meteorological and environmental dynamics (temperature, rainfall, DOC concentrations). The simulations showed that the effective persistence of PCBs in soil is deeply influenced by the seasonal variability. The model also allowed to evaluate the role of DOC as a possible enhancer of PCB degradation as a microorganism \u201cspoon feeder\u201d of PCBs in the soil solution. Additionally, we preliminary predicted how the contribution of PCB metabolites could modify the PCB fingerprint and their final total concentrations. This shows that the SoilPlusVeg model could be used in selecting the best choices for a sustainable rhizoremediation of a POP contaminated site

Factors Affecting Spatial and Temporal Concentration Variability of Pharmaceuticals: Comparison between Two WWTPs

The presence of emerging organic micropollutants (such as pharmaceuticals) in sewage has been, for a long time, an issue of great concern within the international scientific debate. This item represents one of the main challenges related to a sustainable development, with particular concern to the public health control. While most of the work has been concentrated on their detection and the evaluation of their average level, little is known about the spatial and temporal variability of concentrations of these compounds in the effluent and its capability to affect the concentrations in time of the receiving water body. In this study, three sampling campaigns were carried out at two different wastewater treatment plants (WWTPs) in Varese area (Northern Italy) with the aim of monitoring the occurrence of some pharmaceuticals to evaluate their removal efficiency. The detected pharmaceuticals were: Ofloxacin, Ibuprofen, Atenolol, Bezafibrate, Carbamazepine, Salbutamol, Cyclophosphamide and Hydrochlorothiazide. The results obtained, together with the analysis of the characteristics of the chemicals and of the two WWTPs, allowed evaluating the factors affecting the spatial and temporal concentration variability in effluent waters and the potential influence of this variability in driving the exposure of the aquatic ecosystems in the receiving water body

Implementation of Magnetic Nanostructured Adsorbents for Heavy Metals Separation from Textile Wastewater

In the framework of sustainability, water shortages and water pollution are two important aspects to be considered. Proposing efficient and low-impact technologies is of paramount importance to promote circular economies associated with the use of water in the industrial context, especially in the textile industry. In this work, the application of a set of magnetic nanostructured adsorbents (MNAs) to cleanse metal ions from textile wastewaters was studied and analyzed. MNAs were generated with a low-cost process, involving iron (II/III) salts (e.g., chlorides), sodium or ammonium hydroxide solutions, and graphene oxide, obtained from graphite by a modified Hummers' method at room temperature. The shape and the size were studied with transmission electron microscopy. Adsorbents were tested with different metal ions (e.g., copper, chromium (III), and nickel). Metal ion concentrations were analyzed by means of inductively coupled plasma optical emission spectroscopy (ICP-OES), and adsorption isotherms were characterized. From the results, the MNAs exhibited the capability of removing metal ions up to a yield of 99% for Cr3+, 94.7% for Cu2+, and 91.4% for Ni2+, along with adsorption loads up to 4.56 mg/g of MNAs

Rhizoremediation half-lives of PCBs: Role of congener composition, organic carbon forms, bioavailability, microbial activity, plant species and soil conditions, on the prediction of fate and persistence in soil

Polychlorinated biphenyls (PCBs) are persistent organic pollutants widely produced and used in many countries until the increasing concern about their environmental risk lead to their ban in the 1980s. Although their emissions decreased, PCBs are nowadays still present in the environment and can be reemitted from reservoir compartments such as contaminated soils. In the last two decades, there has been a growing interest in bioremediation technologies that use plants and microorganisms (i.e. rhizoremediation) to degrade organic chemicals in contaminated sites. Different studies have been conducted to investigate the potential of plant-microbe interactions in the remediation of organic chemical contaminated soils. They range from short-term and laboratory/greenhouse experiments to long-term and field trials and, when correctly set up, they could provide useful data such as PCB rhizoremediation half-lives in soil. Such type of data are important input parameters for multimedia fate models that aim to estimate the time requested to achieve regulatory thresholds in a PCB contaminated site, allowing to draw up its remediation plan. This review focuses on the main factors influencing PCB fate, persistence and bioavailability in soil including PCB mixture congener composition, soil organic carbon forms, microorganism activity, plant species and soil conditions. Furthermore, it provides an estimate of rhizoremediation half-lives of the ten PCB families starting from the results of literature rhizoremediation experiments. Finally, guidance to perform appropriate experiments to obtain comparable, accurate and useful data for fate estimation is proposed