scholarly journals Removal of TPH, UCM, PAHs, and Alk-PAHs in oil-contaminated soil by thermal desorption

2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Byeongwook Choi ◽  
Sungjong Lee ◽  
Eun Hea Jho

AbstractOil-contaminated soils from a former landfill and gas station site in Korea were treated by thermal desorption. The removal efficiencies of the different oil components such as total petroleum hydrocarbons (TPH), polyaromatic hydrocarbons (PAHs), unresolved complex mixtures (UCM), and alkylated PAHs (Alk-PAHs) by thermal desorption were determined. The effects of temperatures (200, 400, and 600 °C) and treatment times (15, 30, 45, and 60 min) on the thermal desorption efficiency were studied. The treatment efficiency increased with increasing temperature from 200 to 400 °C and with increasing treatment time. Almost complete removals of TPH, UCM, PAHs, and Alk-PAHs were observed after 15 min at 400 °C. The treatment temperatures of 400 and 600 °C did not show a significant difference (p-value > 0.05). Overall, this study shows that the different components of oil in the oil-contaminated soils can be treated effectively in a relatively short time by thermal desorption, and such high removal efficiency in a relatively short time for the oil-contaminated soils can be of advantage for the treatment of highly contaminated or weathered soils where biological treatment efficiency is low.

Author(s):  
Williams, Janet Olufunmilayo ◽  
Aleruchi Owhonka

This study investigated the potential of Aspergillus sydowii and Fusarium lichenicola as mixed cultures in the biodegradation of Total Petroleum Hydrocarbons TPHs in oilfield wastewater. Oilfield wastewater was collected from an onshore oil producing platform and biodegradation of total petroleum hydrocarbons was investigated using standard methods. Fungi were isolated from oilfield wastewater contaminated soils obtained from the vicinity of the oil producing platform. Experimental control set-up and treatment with mixed culture of fungal isolates were periodically analyzed on days 7 and 21 intervals for total petroleum hydrocarbon degradation using Gas Chromatography (GC). The total amount of TPHs on day 1 recorded 381. 871 mg/l.  The amount of TPHs on days 7 and 21 in the mixed culture of fungi was 108.975 mg/l and 21.105 mg/l respectively while TPHs in control was 342.891 mg/l and 240.749 mg/l respectively. There was a significant difference between the mixed culture and the control on days 7 and 21 at p≤0.05. The results therefore revealed actual and significant reduction of TPHs in the mixed culture. In addition, there was clearance of n-alkanes by the mixed culture. This suggests that fungi have great potentials in biodegradation of TPHs and in remediation of TPH contaminated environments.


2020 ◽  
Vol 12 (23) ◽  
pp. 10078
Author(s):  
Sang Hwan Lee ◽  
Jung Hyun Lee ◽  
Woo Chul Jung ◽  
Misun Park ◽  
Min Suk Kim ◽  
...  

For sustainable soil management, there is an increasing demand for soil quality, resilience, and health assessment. After remediation of petroleum hydrocarbon (PHC)-contaminated soils, changes in the physicochemical and ecological characteristics of the soil were investigated. Two kinds of remediation technologies were applied to contaminated soils: land farming (LF) and high temperature thermal desorption (HTTD). As a result of total petroleum hydrocarbons (TPH), PHC-contaminated soils were efficiently remediated by LF and HTTD. The soil health could not be completely recovered after the removal of pollutants due to adverse changes in the soil properties, especially in soil enzyme activities. Therefore, monitoring is necessary for accurate estimation of soil ecotoxicity and effective remediation, and additional soil management, such as fertilizer application or organic amendments, is needed to restore soil heath. In the case of HTTD, soil ecological properties are severely changed during the remediation process. The decision to reuse or recycle remediated soils should reflect changes in soil quality. HTTD is a harsh remediation method that results in deterioration of soil fertility and ecological functions. Alternatives, such as low-temperature thermal desorption or additional soil management using fertilizer or organic amendments, for example, are needed.


2015 ◽  
Vol 86 (1) ◽  
pp. 142-148 ◽  
Author(s):  
Lian O'Dywer ◽  
Simon J. Littlewood ◽  
Shahla Rahman ◽  
R. James Spencer ◽  
Sophy K. Barber ◽  
...  

ABSTRACT Objective:  To use a two-arm parallel trial to compare treatment efficiency between a self-ligating and a conventional preadjusted edgewise appliance system. Materials and Methods:  A prospective multi-center randomized controlled clinical trial was conducted in three hospital orthodontic departments. Subjects were randomly allocated to receive treatment with either a self-ligating (3M SmartClip) or conventional (3M Victory) preadjusted edgewise appliance bracket system using a computer-generated random sequence concealed in opaque envelopes, with stratification for operator and center. Two operators followed a standardized protocol regarding bracket bonding procedure and archwire sequence. Efficiency of each ligation system was assessed by comparing the duration of treatment (months), total number of appointments (scheduled and emergency visits), and number of bracket bond failures. Results:  One hundred thirty-eight subjects (mean age 14 years 11 months) were enrolled in the study, of which 135 subjects (97.8%) completed treatment. The mean treatment time and number of visits were 25.12 months and 19.97 visits in the SmartClip group and 25.80 months and 20.37 visits in the Victory group. The overall bond failure rate was 6.6% for the SmartClip and 7.2% for Victory, with a similar debond distribution between the two appliances. No significant differences were found between the bracket systems in any of the outcome measures. No serious harm was observed from either bracket system. Conclusions:  There was no clinically significant difference in treatment efficiency between treatment with a self-ligating bracket system and a conventional ligation system.


2020 ◽  
Vol 35 (3) ◽  
Author(s):  
Tayyaba Gul Malik ◽  
Hina Nadeem ◽  
Eiman Ayesha ◽  
Rabail Alam

Objective: To study the effect of short-term use of oral contraceptive pills on intra-ocular pressures of women of childbearing age.   Methods: It was a comparative observational study, conducted at Arif memorial teaching hospital and Allied hospital Faisalabad for a period of six months. Hundred female subjects were divided into two groups of 50 each. Group A, included females, who had been taking oral contraceptive pills (OCP) for more than 6 months and less than 36 months. Group B, included 50 age-matched controls, who had never used OCP. Ophthalmic and systemic history was taken. Careful Slit lamp examination was performed and intraocular pressures (IOP) were measured using Goldman Applanation tonometer. Fundus examination was done to rule out any posterior segment disease. After collection of data, we analyzed and compared the intra ocular pressures between the two groups by using ANOVA in SPSS version 21.   Results: Average duration of using OCP was 14.9 months. There was no significant difference of Cup to Disc ratios between the two groups (p= 0.109). However, significant difference was noted between the IOP of OCP group and controls. (p=0.000). Conclusion: OCP significantly increase IOP even when used for short time period.


Author(s):  
Divyesh Kumar ◽  
G. Y. Srinivasa ◽  
Ankita Gupta ◽  
Bhavana Rai ◽  
Arun S. Oinam ◽  
...  

Abstract Background Carcinoma cervix is amongst the leading causes of mortality and morbidity in women population worldwide. High-dose-rate intracavitary brachytherapy (HDR-ICBT) post external beam radiation therapy (EBRT) is the standard of care in managing locally advanced stage cervical cancer patients. HDR-ICBT is generally performed under general anaesthesia (GA) in operation theatre (OT), but due to logistic reasons, sometimes, it becomes difficult to accommodate all patients under GA. Since prolonged overall treatment time (OTT) makes the results inferior, taking patients in day care setup under procedural sedation (PS) can be an effective alternative. In this audit, we tried to retrospectively analyse the dosimetric difference, if any, in patients who underwent ICBT at our centre, under either GA in OT or PS in day care. Results Thirty five patients were analysed 16/35 (45.71%) patients underwent HDR-ICBT under GA while 19/35 (54.28%) patients under PS. In both groups, a statistically significant difference was observed between the dose received by 0.1 cc as well as 2 cc of rectum (p < 0.05), while the bladder and sigmoid colon had comparable dosages. Conclusion Though our dosimetric analysis highlighted better rectal sparing in patients undergoing HDR-ICBT under GA when compared to patients under PS, PS can still be considered an effective alternative, especially in centres dealing with significant patient load. Further studies are required for firm conclusion.


2013 ◽  
Vol 69 (4) ◽  
pp. 703-709 ◽  
Author(s):  
Georgios Roinas ◽  
Cath Mant ◽  
John B. Williams

Sustainable drainage (SuDs) is an established method for managing runoff from developments, and source control is part of accepted design philosophy. However, there are limited studies into the contribution source control makes to pollutant removal, especially for roads. This study examines organic pollutants, total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs), in paired source and non-source control full-scale SuDs systems. Sites were selected to cover local roads, trunk roads and housing developments, with a range of SuDs, including porous asphalt, swales, detention basins and ponds. Soil and water samples were taken bi-monthly over 12 months to assess pollutant loads. Results show first flush patterns in storm events for solids, but not for TPH. The patterns of removal for specific PAHs were also different, reflecting varying physico-chemical properties. The potential of trunk roads for pollution was illustrated by peak runoff for TPH of &gt; 17,000 μg/l. Overall there was no significant difference between pollutant loads from source and non-source control systems, but the dynamic nature of runoff means that longer-term data are required. The outcomes of this project will increase understanding of organic pollutants behaviour in SuDs. This will provide design guidance about the most appropriate systems for treating these pollutants.


2021 ◽  
Vol 19 (1) ◽  
pp. 139-154
Author(s):  
MA Hossain ◽  
MS Yasmin ◽  
MAA Bachchu ◽  
MA Alim

Botanicals are promising and attractive alternatives for pest management. In the present study, three botanical oils namely neem (Azadirachta indica), karanja (Pongamia pinnata) and mehogony (Swietenia mahagoni) were tested against the nymphs of Aphis craccivora Koch to evaluate the toxic and repellent effects under laboratory conditions (25 ± 5oC, 65-75% RH). Four concentrations (0.5, 1.0, 1.5, and 2.0%) along with control were maintained with distilled water and tween-20 was used as emulsifier. Leaf dipped method were used for insect bioassay. Insect mortality was recorded at 24, 48 and 72 hours after intervals while repellency was carried out at 2 hours after intervals upto 10th hours and the collected data were analyzed through MSTAT-C program. Results indicated that all the tested oils had toxic and repellent effects against the A. craccivora nymphs. Among the tested botanical oils, no significant difference was observed in terms of mortality over treatment time. But significant difference was noticed over level of concentrations exerted by the botanical oils. The average highest mortality (28.62%) was recorded by the application of mehogony oil whereas neem oil showed the lowest mortality (27.21%) against the A. craccivora and the mortality was directly proportional to the level of concentrations and hour after treatment (HAT). Probit analysis showed the lowest LD50 values of mehogony oil which revealed the highest toxic effect against the nymph of bean aphid. The highest repellent effect (77.33%) was found in mehogony oil (repellent class IV) among all the botanical oils applied. On the contrary, neem (57.33%) and karanja (55.00%) oils belonged to the same repellent class that is repellent class II. Although all the tested botanical oils evaluated showed toxic and repellent effects but mehogony oil performed as the best potent oil against the nymphs. We therefore suggested using the mehogony oil for the management of bean aphid. SAARC J. Agric., 19(1): 139-154 (2021)


Author(s):  
Sahar Saadatnia ◽  
Azita Tiznobaik ◽  
Amir Saber

Abstract Objectives Nausea and vomiting have psychological negative effects on some pregnant women during gestation. Different strategies have been used for the treatment of nausea and vomiting during pregnancy, such as acupressure and psychological interventions. This study was conducted to evaluate the effects of psychological counseling and acupressure based on couple therapy procedures on vomiting and nausea in pregnant women in Iran. Methods Two hundred and eight women were divided into four groups (n=52): 1) they did not any intervention (control group), 2) they received the psychological intervention, 3) they received acupressure intervention, and 4) they received a combination of psychological + acupressure interventions. To investigate the effects of interventions on nausea and vomiting, the Rhodes index of nausea, vomiting and retching were used. The counseling period has lasted for 4 weeks. The pressure intervention on the site was conducted in clockwise form for 1 min and anticlockwise form for another 1 min. Results Groups did not have a significant difference for abortion and income (p>0.05). The effects of counseling, and acupressure interventions on severity and period of vomiting and nausea were not significant (p>0.05), but the intervention based on counseling and acupressure decreased severity of vomiting and nausea (p<0.05). Conclusions The intervention based on counseling and acupressure could not reduce nausea and vomiting during the gestation, but the intervention based on a combination of both decreased nausea and vomiting. It can be suggested to apply an intervention based on a combination of counseling and acupressure in short-time period for decreasing nausea and vomiting in women during pregnancy.


2001 ◽  
Vol 43 (2) ◽  
pp. 291-295 ◽  
Author(s):  
J. Vouillamoz ◽  
M. W. Milke

The effect of compost on phytoremediation of diesel-contaminated soils was investigated using 130 small (200 g) containers in two screening tests. The experiments were conducted in a controlled environment using ryegrass from seed. Containers were destructively sampled at various times and analyzed for plant mass and total petroleum hydrocarbons. The results indicate that the presence of diesel reduces grass growth, and that compost helps reduced the impact of diesel on grass growth. The addition of compost helps increase diesel loss from the soils both with and without grass, though the addition of grass leads to lower diesel levels compared with controls. A second set of experiments indicates that the compost helps in phytoremediation of diesel-contaminated soil independent of the dilution effect that compost addition has. The results indicate that the compost addition allowed diesel loss down to 200 mg TPH/kg even though the compost would be expected to hold the diesel more tightly in the soil/compost mixture. The simplicity of the screening tests led to difficulties in controlling moisture content and germination rates. The conclusion of the research is that the tilling of compost into soils combined with grass seeding appears to be a valuable option for treating petroleum-contaminated soils.


2002 ◽  
Vol 46 (11-12) ◽  
pp. 183-188 ◽  
Author(s):  
Y. Suzuki ◽  
T. Maruyama ◽  
H. Tegane ◽  
T. Goto

A new method for solid-liquid separation for wastewater incorporating simple operation and shortened treatment time is necessary for improvement of sewage systems. In this study, removal of suspended solids from municipal wastewater by coagulation and foam separation using coagulant and milk casein was examined. By adding casein before the foam separation process, the removal of suspended substances was dramatically improved. The optimum condition for treating sewage was 20 mg-Fe/L of FeCl3, 3 mg/L of casein, and pH 5.5, which resulted in a removal rates of over 98% for turbidity and SS. A removal of 96-98% was also possible for phosphate and anionic surfactant. When PAC was used, the floc was also efficiently recovered in foam by the addition of casein. It became clear that coagulation and foam separation using casein as the collector is an effective method for removing suspended solids in municipal wastewater in a short time (within 10 min).


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