The tomato processing industry generates large quantities of tomato peel residues, usually creating environmental problems. These residues are a significant source of lycopene, thus providing an attractive alternative for profitable handling of these otherwise problematic by-products. The enzymatic pretreatment of these residues for lycopene recovery has already been employed, although the use of surfactants for enhancing the recovery has not been examined so far. The enzymatic pretreatment of tomato peels, using two commercially available pectinolytic enzyme preparations, was evaluated suggesting that there is an optimum pretreatment time of about 1 h, enzyme amount 250 Units/mL and no significant pH influence. Lycopene surfactant - assisted extraction was further investigated, showing that, among eight surfactants used, the most suitable was "Span 20", with an optimum ratio of 6-7 surfactant molecules per lycopene molecule. Sequential enzymatic pretreatment and surfactant-assisted extraction (30 min for each step) was evaluated leading to an improved lycopene extraction yield, with a somewhat smaller surfactant molar ratio (i.e. 4-5). In the latter case, the yield of lycopene recovery was almost four times greater compared to just 1 hr enzymatic pretreatment, and was approximately ten times greater compared to the recovery from untreated peels. Furthermore, such lipophilic compound recovery, avoiding the use of organic solvents, is environmentally attractive and ensures direct lycopene use in the food and cosmetics industries.
In recent years combined chemical-biological wastewater treatment processes have received increasing interest. In the present study wastewater from soil remediation processes were treated by means of 1-step processes like Fenton, aerobic degradation and 2-steps combined method. The effluents resulting from soil remediation processes consist of high surfactant concentration solutions, mobilized oils and oil-in-water (o/w) emulsions. The effectiveness of wastewater treatment was evaluated by COD reduction and surfactant removal. The application of Fenton process alone showed around 80% of COD and surfactant removal, and in case of aerobic process only 60% of COD and 50% of surfactant removal was accomplished. However, the maximum COD reduction and surfactant removal from wastewater samples, above 90%, was obtained in aerobic degradation with Fenton process as pretreatment. Thus, the Fenton process could be effectively applied as a pretreatment step to improve the reduction of both COD and surfactant from wastewater resulting from soil remediation.
PL
Ścieki powstające podczas procesu remediacji gruntu zawierają surfaktanty o wysokim stężeniu oraz oleje w postaci zemulgowanej i zsolubilizowanej lub wolnej. Do oczyszczenia takich ścieków zastosowano chemiczne utlenianie, biologiczne oczyszczanie oraz zintegrowany proces chemiczno-biologiczny. Efektywność procesu oceniono na podstawie redukcji ChZT oraz zmiany stężenia surfaktantu w oczyszczanych ściekach. Chemiczne utlenienie pozwoliło na 80% redukcję ChZT oraz stężenia surfaktantu w ściekach, w przypadku biologicznego oczyszczania parametry te zredukowano odpowiednio o 60% i 50%. Jednak w zintegrowanym procesie biologiczno-chemicznym redukcja zarówno ChZT, jak i stężenia surfaktantu wyniosła ponad 90%. Dlatego też chemiczne utlenienie może być stosowane jako wstępne oczyszczanie przed oczyszczaniem biologicznym w celu poprawy usunięcia zarówno ChZT, jak i surfaktantu w ściekach powstających podczas remediacji gruntów.
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