Ana Gomes

This review aims to study in detail the characterization of winery wastewater (WW), the problems caused by its release into the environment without proper treatment, and the processes that can be applied for its treatment. Several works showed that the WW has a composition based on soluble sugars, organic acids, alcohols, and high molecular weight compounds. Among these, the phenolic compounds are considered to be very toxic, due to the difficulty of degradation by microorganisms, and also because they represent toxicity to humans and animals. To solve this issue, biologic treatments are considered to be cheaper and more effective for biodegradable WW, with the possibility to store biogas with anaerobic treatments. To complement biological treatments, physical-chemical processes based on adsorption, coagulation-flocculation-decantation (CFD), and advanced oxidation processes (AOPs) are also discussed in this review.

Industrial wastewater (IWW) generation is a serious problem when set free into an environment in the absence of appropriate treatment; therefore, industries spot for structured, easy, and low-cost treatment processes. This review intends to present the applicability of sulfate radical’s advanced oxidation processes (SR-AOPs) for IWW treatment. Different peroxymonosulfate (PMS), and persulfate (PS) activation methods are addressed. Laboratory, pilot-scale enforcement of SR-AOPs in IWW treatment, with a focus on the advantages and disadvantages of these processes, are presented.

Acid Red 88 (AR88) is an azo dye highly used in the textile industry. This industry generates high volumes of wastewater with recalcitrant properties that can persist in nature for many years. This work intends to use a statistical model to better predict and understand the influence of different operational conditions. A Box-Behnken response surface methodology (RSM) was used, in which variables (H₂O₂, Fe²⁺, and radiation intensity) were changed. At the same time, the RSM model allowed the assessment of several advanced oxidation processes (AOPs). The results exhibited the photo-Fenton process as the most efficient, and the best operational conditions ([AR88] = 0.125 mM, pH = 3.0, [H₂O₂] = 7.9 mM, [Fe²⁺] = 0.22 mM, time = 30 min) were used in four different reactors (UV-C, UV-A, ultrasound, and solar). US reactors achieved high AR88 removal (98.2%, 50 min), similar to UV-C and UV-A (97.8 and 98.2%, respectively, 60 min). A solar reactor is concluded to be the most feasible choice, with 98.4% AR88 removal after 25 min.

Pathogenic microorganisms such as bacteria, viruses, fungi and protozoa have played a central role in the safety of drinking water, since they spread easily in the water network, constituting a health risk for humans and animals. Currently in water treatments, advanced oxidative processes (AOPs) have been increasing in importance in the microbiological disinfection of water. The present study aimed to inactivate C. albicans, a commensal yeast species in Vertebrates that can cause disease, using AOPs. To achieve this objective, a powerful oxidant (hydrogen peroxide) was combined with UV radiation to promote the inactivation of C. albicans. Initially, the inactivation capacity of the H₂O₂ was assessed and it was verified that the application of 2.5 mM, 5 mM and 10 mM H₂O₂ reached a cell reduction of 3 log after 180, 360 and 300 min, respectively. Subsequently, the combination with UV-A radiation (λ = 365 nm) proved to be even more promising, as the H₂O₂ + UV-A system, using the same H₂O₂ concentrations, reached an inactivation of 3 log after 240, 180 and 60 min, respectively. These results support that UV-A radiation promotes the generation of hydroxyl radicals, which have a comparatively higher oxidation potential (2.8 eV) to the H₂O₂ (1.8 eV), responsible for the inactivation of C. albicans cells. Thus, the UV-A/H₂O₂ process can reduce this microorganism in an aqueous matrix, avoiding potential hazards to human and animal health.

The present study aims to contribute to sustainable development goals by increasing knowledge of food safety and food waste of meals produced by the cook–chill system in hospital units. The food waste (FW) of meals served at lunch was evaluated for all new hospitalized patients with light diet (n = 17) and soft texture diet (n = 10), during their hospital stay, using the physical method by weighing for dish and the visual estimation method for the soup. Samples of each diet (light, n = 3; soft texture, n = 3) were also collected in four different moments (after cooked, after cold transportation, after refrigerated storage and after hot regeneration) for detection and enumeration of Listeria monocytogenes, Salmonella spp. and Staphylococcus aureus and enumeration of Escherichia coli, Clostridium spp., Bacillus cereus, Enterobacteriaceae, total viable counts (TVC) at 30 °C, as well as pH, water activity, moisture, ashes and protein. The FW (%) of the light diet (n = 64) was 39.8 ± 6.3 in dish and 14.9 ± 5.4 in soup, and of the soft texture diet (n = 51) was 65.1 ± 9.0 in dish and 39.0 ± 5.8 in soup. Regarding the percentage of protein per meal, both light (8.73%) and soft (3.33%) diets presented on average values lower than those recommended by the WHO (10–15% protein). The value of different microorganisms varied along the production moments; however, the final products in the light diet (after hot regeneration) presented 1.34–1.73 log cfu/g of TVC. Counts of Bacillus cereus and Staphylococcus aureus were also obtained at low levels (less than 1 log cfu/g). Besides these results, the risk of foodborne diseases should be considered. The implementation of effective measures to increase food safety and reduce FW in hospital is crucial.

Food waste (FW) has been linked with nutrient intake, menu performance, food acceptability, costs and environmental impacts. This study aims to evaluate the FW in the wards of a Portuguese public hospital. The evaluation of the FW of lunch meals was performed during 21 days, to all new hospitalized patients (n = 105) admitted in four hospital wards (Medicine (Med), Paediatrics (Ped), Oncology (Onc) and Orthopaedics (Ort)). For each patient, the type of diet and FW were evaluated during the length of hospital stay (covering 321 meals). The FW of the dish was calculated by the physical method by weighing and the soup by the method of visual estimation, evaluating before and after distribution. The patients have a mean 3.1 ± 2.2 day length of hospital stay. In relation to the FW of the dish per ward, that in the Ped ward it was 72.6%, Med 47.5%, Onc 46.9% and Ort 58.4% (ρ = 0.027). The FW for Ped soup was 67.1%, Med 30.9%, Onc 29.4% and Ort 35.2% (ρ = 0.018). The FW values are high, especially in the paediatric ward. The institutions are unaware of the FW produced and given the magnitude of the problem it is necessary to implement effective measures.