Municipal Treated Wastewater Irrigation: Microbiological Risk Evaluation

Municipal wastewater for irrigation, though treated, can contain substances and pathogens toxic for humans and animals. Pathogens, although not harmful from an agronomical aspect, undoubtedly represent a major concern with regards to sanitary and hygienic profile. In fact, vegetable crops irrigated with treated wastewater exalt the risk of infection since these products can also be eaten raw, as well as transformed or cooked. Practically, the evaluation of the microbiological risk is important to verify if the microbial limits imposed by law for treated municipal wastewater for irrigation, are valid, thus justifying the treatments costs, or if they are too low and, therefore, they don' t justify them. Different probabilistic models have been studied to assess the microbiological risk; among these, the Beta-Poisson model resulted the most reliable. Thus, the Dipartimento di Scienze delle Produzioni Vegetali of the University of Bari, which has been carrying out researches on irrigation with municipal filtered wastewater for several years, considered interesting to verify if the microbial limits imposed by the italian law n.185/03 are too severe, estimating the biological risk by the probabilistic Beta-Poisson model. Results of field trials on vegetable crops irrigated by municipal filtered wastewater, processed by the Beta-Poisson model, show that the probability to get infection and/or illness is extremely low, and that the actual italian microbial limits are excessively restrictive

Irrigation with treated municipal wastewater on artichoke crop: assessment of soil and yield heavy metal content and human risk

Industrial and municipal wastewaters are often used for irrigating agricultural fields in arid and semi-arid countries, representing the most attractive option to alleviate pressure on fresh-water resources. However, the wastewater may contain various potentially toxic elements and organic matters with highly harmful effects on human and animal health. During two growing seasons of globe artichoke, the effects of irrigation with secondary (SWW) and tertiary (TWW) municipal wastewater on heavy metal soil and plant content were evaluated together with the consequent human risk from artichoke head consumption. The heavy metal contents (i.e., Al, Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn, and Mn) of the irrigation water, soil, plant and yield were analyzed. Total and extractable heavy metals were quantified to determine the bioaccumulation factors, and the health risks to adults and children were determined according to hazard indices. The heavy metal contents of the artichoke heads harvested after SWW and TWW irrigation were lower than the international threshold values and low bioaccumulation factors suggested that these heavy metals did not accumulate in the edible part of the artichoke crop. The hazard indices based on the consumption of the artichoke heads remained <1.0 for both adults and children, thus indicating that the health risks involving the different heavy metals are not significant

Productivity of energy sorghum irrigated with reclaimed wastewaters

The sustainability of biomass sorghum ( Sorghum bicolor L. Moench.) in the Mediterranean environment is linked to the possibility of increasing crop productivity by using conventional clean water and wastewater irrigation. An experimental setup was arranged in Southern Italy during 2012 and 2013 seasons to determine the potential productivity of biomass sorghum irrigated with conventional water at different irrigation regimes (100 and 50% of calculated evapotranspiration) and different types of municipal wastewater. During the sorghum growing season, the crop development (biomass and leaf are index) and the soil water content were monitored for all irrigation treatments. The data obtained showed that the dry biomass of sorghum irrigated with the deficit treatment (17 t ha –1 ) was lower compared with conventionally irrigated sorghum. For both seasons and under full irrigated conditions, sorghum irrigated with wastewater produced on average more dry biomass (23 t ha –1 ) than the crop irrigated with conventional water (20.5 t ha –1 ), using the same irrigation volumes

Bioenergy productivity of sugar beet irrigated with reclaimed wastewaters

The use of treated wastewater to irrigate the sugar beet (Beta Vulgaris L. var. saccharifera) for bioethanol could play a strategic role to contrast the use of natural water resources and increase the productivity of the crop. The 2-year experiment (2013-2014) was performed on sugar beet irrigated with fresh water and wastewater at different steps of the reclamation process (secondary and tertiary treatments). The data obtained showed that the root sugar beet yield and ethanol production under fresh water treatment (52.2 Mg ha–1 and 5446 L ha–1) were lower respect to that obtained from the secondary and tertiary wastewater treatments (66.7 Mg ha–1 and 6785 L ha–1, and 58.7 Mg h–1 and 6164 L ha–1, respectively), with the same irrigation volumes. These results can depend on the higher quantity of nutrient uptake when wastewater is used for irrigation. In particular, the average N applied (as nitrate and ammonium) with irrigation during the growing seasons (2013 and 2014) was corresponding to the supply of 4, 28 and 20 kg ha–1, for the fresh water, secondary, and tertiary wastewater treatments, respectively

Evaluating the Student-Teacher Relationship Scale in Italian Young Children: An Exploratory Structural Equation Modeling Approach

The study analyzed the factorial and concurrent validity of the Student-Teacher Relationship Scale (STRS) using an Exploratory Structural Equation Modeling (ESEM) approach. Participants were 368 Italian children aged 3 to 6 (M = 4.60, SD = 0.98). The three-factor ESEM solution fit the data better than the classical confirmatory factor analysis (CFA) model and the measurement invariance of the scale was confirmed across sex and age (3-4 vs. 5-6 years) groups. The concurrent validity of the STRS was investigated within the ESEM approach using children’s social behaviors as validity criteria. Findings supported the goodness of ESEM over CFA and attested to the validity of the STRS to understanding the teacher-child relationship quality in young children

Daily Deviations in Anger, Guilt, and Sympathy: A Developmental Diary Study of Aggression

With a diary study of 4- and 8-year-olds, we tested the association between daily deviations in anger and aggressive behavior, and whether this link was moderated by feelings of guilt and sympathy. Caregivers reported their children’s anger and aggression for 10 consecutive days (470 records; N = 80, 53 % girls). To calculate daily anger deviations from average anger levels, we subtracted each child’s average anger score (i.e., across 10 days) from his/her daily anger scores. Children reported their guilty feelings in response to vignettes depicting intentional harm, as well as their dispositional sympathy levels. Multilevel modeling indicated that within-child spikes in daily anger were associated with more aggression, above and beyond between-child differences in average anger levels. However, this association was weaker for children who reported higher levels of guilt. Sympathy did not moderate the anger-aggression link. We discuss potential implications for affective-developmental models of aggression and interventions that target anger-related aggressio

Agricultural use of treated municipal wastewaters preserving environmental sustainability

In this paper the utility of the treated municipal wastewaters in agriculture, analyzing the chemical, physical and microbiological characteristics and their pollution indicators evaluation are being illustrated. Some methods employed for treating wastewaters are examined, as well as instructions and rules actually in force in different countries of the world, for evaluating the legislative hygienic and sanitary and agronomic problems connected with the treated wastewaters use, are being collected and compared. Successively, in order to provide useful indications for the use of treated municipal wastewaters, results of long-term field researches, carried out in Puglia, regarding two types of waters (treated municipal wastewater and conventional water) and two irrigation methods (drip and capillary sub-irrigation) on vegetable crops grown in succession, are being reported. For each crop cycle, chemical physical and microbiological analyses have been performed on irrigation water, soil and crop samples. The results evidenced that although irrigating with waters having high colimetric values, higher than those indicated by law and with two different irrigation methods, never soil and marketable yield pollutions have been observed. Moreover, the probability to take infection and/or disease for ingestion of fruits coming from crops irrigated with treated wastewaters, calculated by Beta-Poisson method, resulted negligible and equal to 1 person for 100 millions of exposed people. Concentrations of heavy metals in soil and crops were lesser than those admissible by law. The free chlorine, coming from disinfection, found in the wastewaters used for watering, in some cases caused toxicity effects, which determined significant yield decreases. Therefore, municipal wastewaters, if well treated, can be used for irrigation representing a valid alternative to the conventional ones

Effects of Some Environmental Factors on Seed Germination and Spreading Potentials of Silybum marianum Gaertner

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Effects of Some Environmental Factors on Seed Germination and Spreading Potentials of Silybum marianum Gaertner

Silybum marianum Gaertner is spreading in many crops of Southern Italy, particularly in durum wheat, sugar beet and some vegetable crops. Information about its biology are useful to set up effective control strategies. Four experiments were carried out at the Crop Science Department of the University of Bari (Southern Italy). Two trials were conducted in Petri dishes and evaluated the effects of different light, temperature and osmotic stress conditions on the seed germination. Another trial evaluated the ability of seedlings to emerge from different depths. The effects of eight different sowing periods on the plant growth were assessed in the fourth experiment. The highest germination rate was found with constant temperatures of 25 °C or 30 °C and with alternating temperatures of 25- 15 °C for 8 and 16 hours respectively. Germination was affected by the light and was significantly decreased at 0.2 Mpa and completely inhibited at -0.8 Mpa. Plant emergence was strongly reduced from a depth of more than 3 cm. The plant size at the first bloom was reduced by postponing the sowing period from October to February. The same decreasing trend was observed in the number of flower heads and in the number of days required for the first bloom. Results can suggest some important strategies to manage this species. False sowing, followed by irrigation, can be recommended in summer, in order to obtain the highest seed germination. Since the emergence of this plant is very scarce from a depth of more than 3 cm, ploughing can be effective to bury seeds in case of strong disseminations in order to reduce the infestation in the following crop

Bacteriocin production by Pseudomonas syringae pv. ciccaronei NCPPB2355. Isolation and partial characterization of the antimicrobial compound

Pseudomonas syringae pv. ciccaronei strain NCPPB2355 was found to produce a bacteriocin inhibitory against strains of Ps. syringae subsp. savastanoi, the causal agent of olive knot disease. Treatments with mitomycin C did not substantially increase the bacteriocin titre in culture. The purification of the bacteriocin obtained by ammonium sulphate precipitation of culture supernatant fluid, membrane ultrafiltration, gel filtration and preparative PAGE, led to the isolation of a high molecular weight proteinaceous substance. The bacteriocin analysed by SDS-PAGE revealed three protein bands with molecular weights of '76, 63 and 45 kDa, respectively. The bacteriocin was sensitive to heat and proteolytic enzymes, nias resistant to non-polar organic solvents and was active between pH 5.0-7.0. Plasmid-DNA analysis of Ps. syringae ciccaronei revealed the presence of 18 plasmids; bacteriocin-negative variants could not be obtained by cure experiments