Giusy Lofrano

Chemical and biological treatment technologies for leather tannery chemicals and wastewaters: A review

Although the leather tanning industry is known to be one of the leading economic sectors in many countries, there has been an increasing environmental concern regarding the release of various recalcitrant pollutants in tannery wastewater. It has been shown that biological processes are presently known as the most environmental friendly but inefficient for removal of recalcitrant organics and micro-pollutants in tannery wastewater. Hence emerging technologies such as advanced oxidation processes and membrane processes have been attempted as integrative to biological treatment for this sense. This paper, as the-state-of-the-art, attempts to revise the over world trends of treatment technologies and advances for pollution prevention from tannery chemicals and wastewater. It can be elucidated that according to less extent advances in wastewater minimization as well as in leather production technology and chemicals substitution, biological and chemical treatment processes have been progressively studied. However, there has not been a full scale application yet of those emerging technologies using advanced oxidation although some of them proved good achievements to remove xenobiotics present in tannery wastewater. It can be noted that advanced oxidation technologies integrated with biological processes will remain in the agenda of the decision makers and water sector to apply the best prevention solution for the future tanneries.

Removal of Emerging Contaminants from Water and Wastewater by Adsorption Process

Emerging contaminants are chemicals recently discovered in natural streams as a result of human and industrial activities. Most of them have no regulatory standard and can potentially cause deleterious effects in aquatic life at environmentally relevant concentrations. The conventional wastewater treatment plants (WWTPs) are not always effective for the removal of these huge classes of pollutants and so further water treatments are necessary. This chapter has the aim to study the adsorption process in the removal of emerging compounds. Firstly, a brief description of adsorption mechanism is given and then the study of conventional and non-conventional adsorbents for the removal of emerging compounds is reviewed with the comparison between them.

Olive Mill and Winery Wastewaters Pre-Treatment by Coagulation with Chitosan

The pre-treatment of both winery wastewater (WW) and olive mill wastewater (OMW) by coagulation, using a natural organic coagulant, was investigated as a possible alternative to conventional metal based coagulants, in order to produce a potentially reusable organic sludge. Chitosan was chosen as a model natural organic coagulant and the coagulation process was optimized investigating different coagulant doses and pH values. In spite of the notably lower polluting load for the WW compared to the OMW, the efficiency of the chitosan coagulation was found to be high in terms of total suspended solids (81% and 80% for OMW and WW respectively) and turbidity (94% and 92% for OMW and WW respectively) removal for both wastewaters, but a notable difference was observed in terms of organic matter removal (32% and 73% in terms of COD for OMW and WW respectively). Taking into account that the best performances of the coagulation process by chitosan were achieved at the actual pH for OMW as well as no significant differences were observed for WW as the pH was changed, no chemicals addition is required to adjust pH.

Emerging Compounds Removal from Wastewater

The implementation of clean, eco-friendly, less energy and waste producing processes and technologies is realized today with an increasing interest. In order to provide a sustainable development, environmentally friendly substances, novel technologies and new green chemistry options should be exploited. In that respect, in this chapter green chemistry and its principles are reviewed in relation to green technologies for the removal of emerging compounds from water and wastewater.

In situ remediation of contaminated marinesediment: an overview

Sediment tends to accumulate inorganic and persistent hydrophobic organic contaminants representing one of the main sinks and sources of pollution. Generally, contaminated sediment poses medium- and long-term risks to humans and ecosystem health; dredging activities or natural resuspension phenomena (i.e., strongly adverse weather conditions) can remobilize pollution releasing it into the water column. Thus, ex situ traditional remediation activities (i.e., dredging) can be hazardous compared to in situ techniques that try to keep to a minimum sediment mobilization, unless dredging is compulsory to reach a desired bathymetric level. We reviewed in situ physico-chemical (i.e., active mixing and thin capping, solidification/stabilization, chemical oxidation, dechlorination, electrokinetic separation, and sediment flushing) and bio-assisted treatments, including hybrid solutions (i.e., nanocomposite reactive capping, bioreactive capping, microbial electrochemical technologies). We found that significant gaps still remain into the knowledge about the application of in situ contaminated sediment remediation techniques from the technical and the practical viewpoint. Only activated carbon-based technologies are well developed and currently applied with several available case studies. The environmental implication of in situ remediation technologies was only shortly investigated on a long-term basis after its application, so it is not clear how they can really perform.

Advanced Oxidation Processes for Antibiotics Removal: A Review

DOI: 10.2174/1385272821666170103162 813 Abstract: Year-by-year, the amount of antibiotics for human and veterinary use increases. Their presence in both treated and untreated wastewater was highlighted in several studies, suggesting that traditional activated sludge processes are unsuitable for their efficient removal. In this review paper, we summarized the role of advanced oxidation processes (AOPs) in antibiotics removal evidencing their pros, cons and limitations. In most cases, they are still applied at laboratory or pilot scale, with just few examples of full-scale applications. Main constraints are related to energy cost, catalyst management and potential residual toxicity in treated effluents. The main advantages are related to the full mineralization of target compounds or the ability to increase their relative biodegradability. Future challenges include nano-based green synthetized catalysts maximizing the use of solar radiation for energy saving. Generally, AOPs application is part of a more structured wastewater treatment process including operating units at various technological contents.

Effects of nanoparticles in species of aquaculture interest

AbstractRecently, it was observed that there is an increasing application of nanoparticles (NPs) in aquaculture. Manufacturers are trying to use nano-based tools to remove the barriers about waterborne food, growth, reproduction, and culturing of species, their health, and water treatment in order to increase aquaculture production rates, being the safe-by-design approach still unapplied. We reviewed the applications of NPs in aquaculture evidencing that the way NPs are applied can be very different: some are direclty added to feed, other to water media or in aquaculture facilities. Traditional toxicity data cannot be easily used to infer on aquaculture mainly considering short-term exposure scenarios, underestimating the potential exposure of aquacultured species. The main outputs are (i) biological models are not recurrent, and in the case, testing protocols are frequently different; (ii) most data derived from toxicity studies are not specifically designed on aquaculture needs, thus contact time, exposure concentrations, and other ancillary conditions do not meet the required standard for aquaculture; (iii) short-term exposure periods are investigated mainly on species of indirect aquaculture interest, while shrimp and fish as final consumers in aquaculture plants are underinvestigated (scarce or unknown data on trophic chain transfer of NPs): little information is available about the amount of NPs accumulated within marketed organisms; (iv) how NPs present in the packaging of aquacultured products can affect their quality remained substantially unexplored. NPs in aquaculture are a challenging topic that must be developed in the near future to assure human health and environmental safety. Graphical abstractᅟ

An integrated chemical and ecotoxicological assessment for the photocatalytic degradation of vancomycin

The photocatalytic degradation of an antibiotic, vancomycin B hydrochloride (VAN-B), has been investigated in aqueous suspensions of titanium dioxide (TiO2) by monitoring the change in its concentration as well as the production of ammonia and chlorides as a function of irradiation time. The removal of 50 mg L−1 VAN-B solution yields maximum concentrations of 2.45 and 2.53 mg N-NH3 L−1 after 120 min of photocatalytic oxidation using 0.1 and 0.2 g TiO2 L−1, respectively. When 0.2 g TiO2 L−1 were applied up to 87% of the stoichiometric amount of chloride was reached within 120 min of irradiation, corresponding to 0.087 mmol L−1. A set of bioassays (Daphnia magna, Pseudokirchneriella subcapitata and Ceriodaphnia dubia) was performed to evaluate the potential detoxification of VAN-B and its by-products of oxidation under chronic and acute tests. The toxicity of the treated VAN-B samples varied during the oxidation, due to the formation of some intermediate products more toxic than VAN-B. Despite almost total removal of VAN-B that was achieved within 120 min of irradiation, a significant increase in toxicity was observed in chronic tests proving that the chronic assays are more appropriate than acute ones to detect the impact of by-products formed during the photocatalytic degradation of antibiotics.

Treatment of reactive dyes and textile finishing wastewater using Fenton's oxidation for reuse

Fentons oxidation (FO) was used to decolourise and degrade some reactive dyes (Remazol Black 5, Remazol Red, Remazol Blue, Remazol Yellow) and raw textile finishing industry effluents (S1, S2, S3) containing mainly reactive dyes. The operational conditions for pH varied between 2.5 and 4.0 while temperature ranged from 30oC to 50oC. The concentrations of FeSO4 and H2O2 varied to a wide range (200-600 mg/l of FeSO4, 300-1000 mg/l of H2O2) depending on the type of the dyes and their mixture and textile additives used in the process. FO is highly effective for colour removal (>99%) for reactive dyes and (87-94%) for textile finishing wastewater. It can be applied as a pretreatment and the remaining total dissolved solids (TDS) can be removed by an additional advanced process, e.g. membrane process.

A comprehensive approach to winery wastewater treatment: a review of the state-of the-art

Winery industries generate large volumes of high-strength wastewater whose characteristics greatly vary depending on either seasons, production technologies or scale of the wineries. Winery wastewater (WW) is persistent to degrade by means of the conventional activated sludge process because of the high organic loading and polyphenolic content especially during vintage. To face this situation, a number of processes have recently been attempted as alternatives or integrative to biological treatments. However, there is still no agreement on the best practice to treat WW. Despite even more stringent standards, untreated or partially treated effluents continue to be improperly discharged into aquatic or soil matrixes, influencing microbial communities and physicochemical soil properties. This work presents a review on the state-of-the-art of management of wastewater originated from winery industries. Advantages and drawbacks of the treatment technologies at bench-, pilot-, and full-scale applications in the scientific literature have been considered to draw out a sustainable management scheme.