1、STD-API/PETRO PUBL 4b55-ENGL 1577 E Il732270 Ob03137 T3T W American Petroleum Ins titute FIELD EVALUATION OF BIOLOGICAL AND NON-BIOLOGICAL TREATMENT TECHNOLOGIES TO REMOVE MTBE/OXYGENATES FROM PETROLEUM PRODUCT TERMINAL WASTEWATERS Health and Environmental sciences Department Publication Number 4655
2、 August 1997 FLUUZED BED BKKOGICAL REACTON - YI I .!i lol o - STD-APIIPETRO PUBL ib55-ENGL 1777 0732290 Ob03140 751 One of the most significant long-term trends affecting the future vitality of the petroleum industry is the publics concerns about the environment, health and safety. Recognizing this
3、trend, API member companies have developed a positive, forward-looking strategy called STEP: Strategies for Todays Environmental Partnership. This initiative aims to build understanding and credibility with stakeholders by continually improving our industrys environmental, health and safety performa
4、nce; documenting performance; and communicating with the public. API ENVIRONMENTAL MISSION AND GUIDING ENVIRONMENTAL PRINCIPLES The members of the American Petroleum Institute are dedicated to continuous efforts to improve the compatibility of our operations with the environment while economically d
5、eveloping energy resources and supplying high quality products and services to consumers. We recognize our responsibility to work with the public, the government, and others to develop and to use natural resources in an environmentally sound manner while protecting the health and safety of our emplo
6、yees and the public. To meet these responsibilities, API members pledge to manage our businesses according to the following principles using sound science to prioritize risks and to implement cost-effective management practices: 4 To recognize and to respond to community concerns about our raw mater
7、ials, products and operations. 4 To operate our plants and facilities, and to handle our raw materials and products in a manner that protects the environment, and the safety and health of our employees and the public. 4 To make safety, health and environmental considerations a priority in our planni
8、ng, and our development of new products and processes. 9 To advise promptly, appropriate officials, employees, customers and the public of information on significant industry-related safety, health and environmental hazards, and to recommend protective measures. 9 To counsel customers, transporters
9、and others in the safe use, transportation and disposal of our raw materials, products and waste materials. 9 To economically develop and produce natural resources and to conserve those resources by using energy efficiently. 9 To extend knowledge by conducting or supporting research on the safety, h
10、ealth and environmental effects of our raw materials, products, processes and waste materials. 9 To commit to reduce overall emission and waste generation. 9 To work with others to resolve problems created by handling and disposal of hazardous substances from our operations. 9 To participate with go
11、vernment and others in creating responsible laws, regulations and standards to safeguard the community, workplace and environment. 9 To promote these principies and practices by sharing experiences and offering assistance to others who produce, handle, use, transport or dispose of similar raw materi
12、als, petroleum products and wastes. STD*API/PETRO PUBL Lib55-ENGL 1777 0732210 ObU3LLi1 by8 M Field Evaluation of Biological and Non-Biological Treatment Technologies to Remove MTBWOxygenates from Petroleum Product Terminal Wastewaters Health and Environmental Sciences Department API PUBLICATION NUM
13、BER 4655 PREPARED UNDER CONTRACT BY: W.T. TANG AND P.T. SUN SHELL DEVELOPMENT COMPANY ENVIRONMENTAL DIRECTORATE HOUSTON, TEXAS AUGUST 1997 American Petroleum Ins titu te STD.API/PETRO PUBL qb55-ENGL 1997 m 0732290 Ob03192 524 D FOREWORD API PUBLICATIONS NECESSARILY ADDRESS PROBLEMS OF A GENERAL NATU
14、RE. WITH RESPECT TO PARTICULAR CIRCUMSTANCES, LOCAL, STATE, AND FEDERAL LAWS AND REGULATIONS SHOULD BE REVIEWED. API IS NOT UNDERTAKING TO MEET THE DUTIES OF EMPLOYERS, WAC- TURERS, OR SUPPLIERS TO WARN AND PROPERLY TRAIN AND EQUIP THEIR . EMPLOYEES, AND OTHERS EXPOSED, CONCERNING HEALTH AND SAFETY
15、RISKS AND PRECAUTIONS, NOR UNDERTAKING “ER OBLIGATIONS UNDER LOCAL, STATE, OR FEDERAL LAWS. NOTHING CONTAINED IN ANY API PUBLICATION IS TO BE CONSTRUED AS GRANTING ANY RIGHT, BY IMPLICATION OR OTHERWISE, FOR THE MANU- FACTURE, SALE, OR USE OF ANY METHOD, APPARATUS, OR PRODUCT COV- ERED BY LETERS PAT
16、ENT. NEITHER SHOULD ANYTHING CONTAINED IN ITY FOR INFRINGEMENT OF LEITERS PAm. THE PUBLICATION BE CONSTRUED AS INSURING ANYONE AGAINST LIABIL- All rights reserved. No parr of this work may be reproduced, stored in a retrieval system or transmitted by any mans. electronic, mechanical, photocopying, r
17、ecording, or otherwise. without prior written permission from the pubiishei: Contact the publisher. APl Publishing Services, 1220 L Srreer. N. W, Washington, D. C. 20005. Copyright Q 1997 American Petroleum Institute iii STD.API/PETRO PUBL 4b55-ENGL 1777 10732290 ObO3143 LiLO I ACKNOWLEDGMENTS THE F
18、OLLOWING PEOPLE ARE RECOGNIZED FOR THEIR CONTRIBUTIONS OF TIME AND EXPERTISE DURING THIS STUDY AND IN THE PREPARATION OF THIS REPORT: MI STAFF CO NTACTS Larry Magni, Manufacturing, Distribution gasoline additives such as methyl tert-butyl ether (MTBE); and inorganics. MTBE is added to gasoline as an
19、 oxygenate to reduce automobile tailpipe emission of carbon monoxide and hydrocarbons. MTBE has been shown to be more soluble in water, less strippable, less adsorbable, and more difficult to biodegrade than BTEX, and presents a significant challenge fiom a wastewater treatment standpoint. This proj
20、ect investigates the feasibility of different treatment technologies for removal of BTEX and MTE3E in low-concentration-high-flow marketing terminal wastewaters. Treatment technologies for MTBE removal include activated carbon adsorption, steam stripping, air stripping with and without off-gas contr
21、ol, air stripping at elevated temperature, biological processes, and advanced oxidation processes. Among these treatment technologies, much information has been available for the activated carbon adsorption and air stripping processes. This current study focuses on evaluating the effectiveness of MT
22、BE removal in two biological processes-the fluidized bed biological reactor (FBBR) process and the activated sludge process, and a chemical process-the W-H202 process. The study was conducted at a petroleum product marketing terminai. Contaminated groundwater for that terminal made up the primary co
23、mponent of the wastewater used in the study. The wastewater contained about 3-4 mg/L BTEX and 0.5 mg/L MTBE. Additional MTBE was in some cases injected into the feed to vary the influent feed MTBE concentration. In the FBBR study a 190-gallon reactor was used. It was filled with fluidized granular c
24、arbon particles on which bacteria could grow. The FBBR required a long startup time to build up a sufficient population of the MTBE degraders to exhibit effective MTBE biodegradation even ES-I with an initial inoculation of a large quantity of the MTBE degrading mixed culture. The very slow buildup
25、of the MTBE degrading bacteria in the FBBR was believed to result from the iron interference and the low temperature of the groundwater. Iron hydroxide deposited on carbon particles tended to flocculate the biomass. As the iron flocs sloughed off of carbon particles and elutriated out of the FBBR, l
26、oss of biomass from the FBBR resulted, thus slowing down the attachment of the culture. However, once the MTBE degraders were retained in the FBBR, the FBBR exhibited consistent MTBE removal and excellent stability against process upset. in lieu of the long startup time under field conditions, pre-i
27、mmobilization of a large population of MTBE degraders onto the carbon particles before startup could be a viable alternative to ensure the success of the FBBR process for MTBE treatment. This study demonstrated that removal of MTBE to less than 100 pgL in the FBBR effluent could be achieved with a M
28、TBE loading rate of approximately 40 mg MTBE/L-reactor/day. It is likely that the FBBR can handle higher MTBE loadings if sufilCient time is allowed for the FBBR to accumulate enough of an MTBE degrader population. In the activated sludge process, incorporation of iron flocculation in the activated
29、sludge operation helped retain the MTBE degraders in the system. As a result, very good MTBE degradation and effluent quality can be achieved in the activated sludge system even at an influent biochemical oxygen demand (BOD) concentration as low as 11 ma. The removal of MTBE in the activated sludge
30、system was largely due to biodegradation. Loss of MTBE through volatilization was determined to be oniy 0.5 to 9% of the influent MTBE loading. Based on the test data, an effluent of less than 100 pg/L MTBE could be achieved with a MTBE loading rate of less than 1 O mg/day/l-reactor. This loading ra
31、te was considered a conservative value for sizing the MTBE biodegradation capacity in an activated sludge system. Overall, the activated sludge system does not possess as high a biomass concentration as the FBBR, and therefore requires a larger reactor to handle the same MTBE loading. The activated
32、sludge system was also more prone to process upset than the attached film process used in the FBBR, and recovered at a slower pace. However, the activated sludge process could be started up (or re-started) rather ES2 - STD*API/PETRO PUBL 4b55-ENGL 1777 0732270 Ob03158 771 D easily as compared to the
33、 FBBR, which was shown to be delayed by low temperature and iron interference. The UV-H202 process was capable of effectively degrading MTBE and other gasoline hydrocarbons under high MTBE and organic loading rates. Using a photoreactor equipped with three 1 O-kW W lamps, less than 1 O0 pg/L MTBE in
34、 the effluent could be achieved for a MTBE loading rate of up to 4800 ma-reactorlday. The hydraulic retention time used in the study ranged fiom 3 to 8 minutes. Despite its high degradation rate, there was only a small reduction in the total organic carbon through the W-H202 process, indicating that
35、 most of the organic contaminants were not oxidized to COZ. The by-products were likely to be alcohols, aldehydes and ketones. The aquatic toxicity of the treated effluent from the W-H202 process was not addressed in this study, but should be carefully examined when choosing this technology. The con
36、taminated groundwater contained naurally occurring soluble iron. The soluble iron would compete with the target organic compounds for hydroxyl radicals rendering the process less effective. In addition, once iron was oxidized, it formed iron hydroxide flocs which adsorbed and scattered the W light.
37、Fouling of the W lamp quartz sheath by iron deposition could also occur. Therefore, presence of iron in the feed water would significantly reduce the degradation efficiency of the W-H202 process under neutral pH condition, and the W-H202 process should incorporate an iron removal pretreatment step.
38、However, if the pH of the feed water was lowered to 3.5 or less, the generation of hydroxyl radicals through Fentons reaction was increased and the hydroxyl radical scavengers such as bicarbonate and carbonate were eliminated. As a result, the overall degradation efficiency of the W-H202 process was
39、 significantly increased. The degradation of organic contaminants in the W-H202 process involves complex chain reactions, of which most of the kinetic information is not known. Prediction of the reaction results will be difficult, and laboratory andlor pilot testing is strongly recommended before se
40、lecting the process and sizing of the equipment. ES-3 - STD-API/PETRO PUBL ibS5-ENGL 1997 = 07322.90 Ub03359 82tl D This study provided some engineering design data, such as gasoline additives such as methyl tea-butyl ether (MTBE); and inorganics. MTBE is added to gasoline as an oxygenate to help re
41、duce automobile tailpipe emission of carbon monoxide and hydrocarbons. Among the organic contaminants, MTBE presents the greatest technical challenge from a treatment standpoint. The use of MTBE in gasoline blending has increkd significantly because of the recent mandate by the Clean Air Act Amendme
42、nts of 1993 to increase the oxygenate content in gasoline products. MTBE has a moderately high solubility in water, approximately 50,000 mgL at 25 OC. Consequently, high levels of MTBE are often detected in wastewater or runoff water that has been in contact with gasoline products. For example, the
43、MTBE concentration in tank bottoms is in the range of several thousand mg/L. In groundwater or runoff water contaminated with gasoline, MTBE at the level of several hundred mg/L has been detected. Current regulation on MTBE concentration in gasoline contaminated wastewater from marketing terminais v
44、aries with location. The office of Water of the Environmental Protection Agency is currently developing a drinking water health advisory for MTBE in drinking water. Several states have set guidelines to regulate MTBE concentration in the groundwater discharge permit, ranging from 50 to 1000 pg/L. In
45、 some states, even though MTBE may not be regulated in the discharge permit for treated terminal wastewater, a discharge limit on the total volatile organic concentration (VOC) is usually specified at 100 pg/L. Since MTBE is detected in the VOC measurement, and since it is 1-1 more difficult to remo
46、ve than the other components from gasoline contaminated water, MTBE is essentially the governing factor regulated under this blanket VOC hit. MIS Marketing Terminal Effluent Task Force has sponsored extensive research on the treatment of low-volume-high-concentration tank water bottoms (Voung et al.
47、, 1993). Although the treatment processes evaluated have been successful in meeting certain treatment goals, these treatment processes cannot be readily adapted to the treatment of the high-volume-low-strength wastewaters, particularly when the wastewater contains MTBE. In 1991, API conducted anothe
48、r study to evaluate cost-effective, alternative treatment technologies for reducing the concentrations of MTBE and methanol in groundwater (NI, 1991). The study evaluated five technologies: air stripping (with off- gas carbon adsorption or off-gas incineration), steam stripping, diffused aeration, b
49、iological treatment, and UV-catalyzed oxidation. Cost estimates showed that UV- catalyzed oxidation, air stripping with off-gas incineration, and air stripping with off-gas carbon adsorption were the most cost-effective of the MTBE treatment technologies considered. Most of the data used in this report were denved using some laboratory evaluations and theoretical calculation. Although a biological katment option was evaluated, it was judged to be one of the most expensive options, in part because conservative design parameters were used. Biodegradation of M
