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1

Remediation of aged hydrocarbon contaminated soil by washing in fluidized bed column

Aouf Mohhamed, Dounit Salah

Archives of Environmental Protection

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2022

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Vol. 48, no. 2

15--23

EN

Soil contamination with hydrocarbons represents a worldwide problem, especially for oil-rich countries. soil contamination becomes inevitable due to different accidents, aboveground spills, and leakage, threatening the fauna and flora. The purpose of this study is to remediate One-year aged contaminated soil with crude oil (23490 mg/kg) using the fluidization technique in a laboratory-scale column. Free water and surfactant solutions were used for washing at different operating conditions. The efficiency of the method was evaluated by the calculation of the total petroleum hydrocarbons (TPH) removal ratio. Without the addition of surfactant, the cleaning operation was not sufficiently efficient, especially at room temperature where the removal ratio was only about 18%. Raising the liquid temperature leads to some improvement where the TPH removal ratio reached 49% at 50°C. With the use of solutions containing Sodium Laureth Sulfate (SLES) as a surfactant, an important enhancement of removal ratio was noted, along with an important reduction in operating time, washing solution volume, and energy consumption. The use of alternatively working/stopping operation mode contributes to the improvement of efficiency. TPH removal ratios up to 99% were obtained under some favorable conditions. This research shows encouraging results for expanding towards the industrial level with clean and sustainable resources.

2

An Investigation on the Lead Removal from Soil Contaminated by Mining and Industrial Wastes Using Soapnut in Batch Washing Process

Ugwu Elijah Chibuzo, Sen Gupta Bhaskar, Meza-Figueroa Diana, Razo-Soto Israel, Araiza-Reyna Esaú Anybal, Martínez-Villegas Nadia

Journal of Ecological Engineering

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2021

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Vol. 22, nr 2

1--16

EN

Eco-friendly saponin from soapnut was studied for the remediation of the soils contaminated by lead. This study applied a full factorial design of the experiment with 3-factors in 3-level (3×3 factors) to evaluate the effect and interactions of the washing parameters on the lead removal by soapnut in a batch experiment. The parameters studied include: soil-solution ratio, surfactant concentrations by mass, and pH of the washing solution. Two soil samples representing low lead concentration (C1) and high lead concentration (C2) were investigated. The findings indicate that the removal efficiency obtained, increases along with the soil-solution ratio and surfactant concentration, but decreases with an increase in the pH of washing solution. Polynomial models were developed to predict the experimental response and optimal conditions. The model predicted a maximum of 50.54% and 47.44% lead removal from the contaminated soil C1 and C2, respectively. Multiple washing was investigated using the higher values of the parameters; the responses obtained significantly increased the percentage of lead removed and achieved 79.98% removal for C1 and 77.49% removal for C2. The effective performance of the soil washing process demonstrates the potential usage of soapnut saponin in the remediation of contaminated soil. Saponin from soapnut is cheap and environment-friendly.

3

Możliwości wykorzystania biosurfaktantów w procesach remediacji środowiska gruntowo-wodnego

Kołwzan B.

Ochrona Środowiska

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2014

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Vol. 36, nr 3

3--18

PL

Wytwarzanie biosurfaktantów przez mikroorganizmy związane jest głównie z mechanizmem pobierania hydrofobowych substratów pokarmowych. Wykazano, że biosurfaktanty mogą z dużym powodzeniem zastępować syntetyczne środki powierzchniowo czynne nie tylko w różnych gałęziach przemysłu, medycynie i rolnictwie, ale także w dziedzinie ochrony środowiska. Podstawowe kierunki ich wykorzystania w ochronie środowiska to bioremediacja oraz procesy związane z ekstrakcją zanieczyszczeń na drodze tzw. płukania gruntu. Efektem ich działania jest wzrost rozpuszczalności węglowodorów wchodzących w skład produktów naftowych, co umożliwia ich wykorzystanie w charakterze substratu pokarmowego przez mikroorganizmy. Biosurfaktanty okazały się także przydatne w procesach usuwania z gruntu fazy gęstych niewodnych cieczy (DNAPL) na drodze przemywania. Możliwe jest także wykorzystanie biosurfaktantów anionowych do tzw. mycia gruntów skażonych pierwiastkami śladowymi. Skuteczność oczyszczania skażonych gruntów z użyciem biosurfaktantów zależy od wielu czynników biologicznych oraz fizyczno-chemicznych, związanych np. z rodzajem, stężeniem i wiekiem danego zanieczyszczenia, heterogenicznością gruntu oraz stężeniem i rodzajem zastosowanego biosurfaktantu. Z uwagi na ilość zużywanego w tych procesach związku powierzchniowo czynnego konieczne jest dalsze obniżenie kosztów produkcji biosurfaktantów.

EN

Biosurfactant production is mainly related to hydrophobic nutrient uptake by microorganisms. It was demonstrated that biosurfactants might successfully substitute for synthetic surface-active agents not only in different branches of industry, medicine and agriculture but also in the environmental field. Bioremediation and processes related to extraction of contaminants via so called soil flushing are their principal applications in the environmental protection. Biosurfactants increase the mineral oil hydrocarbon solubility, allowing for their use as nutrients by microorganisms. Biosurfactants are also useful in processes of dense non-aqueous-phase liquid (DNAPL) removal from soil by means of soil flushing. Moreover, anionic biosurfactants may also be used for so called washing of soils contaminated with trace metals. Efficacy of the contaminated soil remediation with biosurfactants depends on many biological and physico-chemical factors, related to e.g. the contamination type, concentration and its age, soil heterogeneity as well as type and concentration of the biosurfactant used. Due to the amounts of surface-active agent used it is necessary to further reduce the costs of biosurfactant production.

4

Tannic acid as a cost-effective substitute for saponin in soil remediation

Gusiatin Z. M., Bułkowska K., Pokój T.

Environmental Biotechnology

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2014

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Vol. 10, No. 2

66--72

EN

The efficiency of soil washing with tannic acid (TA) and saponin (SAP) was compared. In the contaminated soil, Cu and Zn were more mobile than Pb. At 3% concentration, both biosurfactants removed similar amounts of Zn (48 and 54%, respectively), SAP removed somewhat more Cu (81%), and TA removed considerably more Pb (63%). SAP removed more Cu due to its higher number of carboxylic groups. TA dissolved the more stable forms of metals because of its higher acidity resulting from the content of phenolic groups. Based on the potential ecological Risk Index (RI), both biosurfactants reduced the risk posed by the contaminated soil from "considerable" (RI=364 ) to "low" (RI=118, on average). These results, and the fact that TA is more than three times less expensive than SAP, make TA an attractive substitute for SAP in soil washing.

5

Usuwanie hydrofobowych zanieczyszczeń organicznych z gleby metodą odmywania roztworami mieszanin surfaktantów cukrowych i gemini

Pastewski S., Bardachowska A., Mędrzycka K.

Inżynieria i Aparatura Chemiczna

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2011

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Nr 5

84-85

PL

Zbadano wpływ surfaktantów gemini w mieszaninach z alkilopoligluko-zydami na odmywanie heksadekanu z gleby. Dodatek surfaktantu gemini powodował wzrost usunięcia heksadekanu z gleby torfowej w stosunku do roztworów czystego Tritonu BG10. Największy wzrost efektywności uzyskano stosując hydrofilowe surfaktanty gemini Surfynole S465 i S485 w stężeniu 0,5 g/dnrl W przypadku gleby piaszczystej nie stwierdzono poprawy usunięcia heksadekanu w wyniku dodania surfaktantów gemini.

EN

The influence of different gemini surfactants in mixtures with alkylpolyglu-cosides - Triton BG10 on removal of hexadecane from soil was investigated. Addition of gemini surfactant resulted in improve hexadecane removal from peat soil. Best results were obtained using hydrophilic gemini surfactants Surfynol S465 and S485 at concentration of 0.5 g/dm3. In the case of sandy soil there was no improvement in removal of hexadccane by the addition of gemini surfactants.

6

Zastosowanie surfaktantów niejonowych do usuwania zanieczyszczeń chloroorganicznych z gleby

Pastewski S., Potkańska M., Mędrzycka K.

Inżynieria i Aparatura Chemiczna

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2009

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Nr 5

88-89

PL

Zbadano solubilizację micelarną tetrachloroetylenu w roztworach al-kilopoliglukozydów (Triton BG10 i AG (>210). Przeprowadzono procesy przemywania gleby zanieczyszczonej tetrachloroetylenera przy użyciu roztworów alkilopoliglukozydów oraz oksyetylenowanych alkoholi (Rokanole NL5, NL6, NL8, L7, L10). Określono wpływ hydrofilowości surfaktantu i jego stężenia na efektywność przemywania gleby.

EN

Micellar solubilization of tetrachloroethylene in solutions of alkylpoly-glucosides (Triton BG10, AC 6210) and ability of alkylpolyglucosides and polyethoxylated alcohols (Rokaiiol NL5, NL6, NL8, L7, L10) for removal of tetrachloroethylene from soil were investigated. Influence of hydrophilicity of surfactants and their concentration in solution on washing efficiency was investigated.