[Investigating the efficiency of ultraviolet irradiation for inactivation of free living nematodes in water]

Free living nematodes due to their active movement and resistance to chlorination; don't remove in conventional water treatment processes thus can be entered to distribution systems and cause adverse health effects. UV irradiation can be used as a method of inactivating these organisms. This study is done to investigate the effect of ultraviolet lamp on inactivation of free living nematode [Rhabitidae] in water. The effects of duration of irradiation, turbidity, temperature, UV dose and pH are investigated in this study. Ultraviolet lamp used in this study was a 11 watt lamp with intensity of 24 micro w / cm[2]. Contact time required to achieve 100% efficiency for larvae nematodes and adults were 9 and 10 minutes, respectively. Increase of turbidity up to 25 NTU decreased inactivation efficiency of larvae and adult nematodes from 100% to 66% and 100% to 64%, respectively. Change in pH ranged from 6 to 9 did not affect the efficiency of inactivation. With increasing temperature inactivation rate increased. The results showed that there was a significant correlation between the increase in contact time, temperature rise and turbidity reduction with inactivation efficiency of lamp]p<0.001[. Also the effect of the lamp on inactivation of larvae nematode was more than the adults

Occurrence of aflatoxin M1 in raw milk produced in Ardebil of Iran

Contamination of milk and dairy products to aflatoxin M1 is a risk for human and it can be a public heath concern. The aim of this study was to evaluate the presence of aflatoxin M1 in raw milk samples produced in Ardebil City [Iran] by ELISA [Enzyme Linked Immuno Sorbent Assay] technique. 122 samples of raw milk were collected from milk collecting centers and dairy plants in the region and aflatoxin M1 contamination was detected in all of milk samples. The mean concentration of aflatoxin M1 was 40.01ng/L and 14.75 percent of the samples had higher levels than the maximum recommended limits by ISIRI, European Community and Codex Alimentarius. With a view of the fact that milk is used by all the age groups including infants and children in the city of Ardebil, it is necessary to apply an ideal recommended limit to minimize the health hazard from aflatoxin M1 contamination in milk. Application of Good Agricultural Practices and Good Veterinary Practices by agriculture and also the Hazard Analysis and Critical Control Points [HACCP] system as a draft code of practice for preharvest and postharvest control of dairy cow's feed and in milk and dairy products processing is effective

Removal of arsenic from an aqueous solution by pretreated waste tea fungal biomass

Arsenic contamination in water poses a serious threat on human health. The tea fungus known as Kombucha is a waste produced during black tea fermentation. The objective of this study was to examine the main aspect of a possible strategy for the removal of arsenates employing tea fungal biomass. The pretreatment of biomass with FeCl3 was found to improve the biosorption efficiency. Arsenics uptake was found to be rapid for all concentrations and reached to 79% of equilibrium capacity of biosorption in 20 min and reached equilibrium in 90 min. The pseudo second-order and first-order models described the biosorption kinetics of As [V] with good correlation coefficient [R2>0.93] and better than the other equations. The data obtained from the experiment of biosorption isotherm were analyzed using the Freundlich and Langmuir isotherm models. The equation described the isotherm of As [V] biosorption with relatively high correlation coefficient [R2>0.93]. According to the Langmuir model, the maximum uptake capacities [qm] of tea fungal biomass for As [V] were obtained 3.98 +/- 10-3 mmol/gr. The effect of Na+, K+, Mg+2 and Ca+2 on equilibrium capacities of As was not significant. The variation of sorption efficiency with pH showed that optimum biosorption takes place in the pH ranges of 6 to 8. Promising results were obtained in laboratory experiments and effective As [V] removals were observed