1、American Petroleum Ins ti tu te ANALYSIS AND REDUCTION OF TOXICITY IN BIOLOGICALLY TREATED PETROLEUM PRODUCT TERMINAL TANK BOTTOMS WATER Health and Environmental Sciences Department Publication Number 4665 April 1998 STD.API/PETRO PUBL 4bb5-ENGL 1778 0732270 0606747 273 W % American Petroleum Instit
2、ute American Petroleum Institute Environmental, Health, and Safety Mission and Guiding Principles MISSION The members of the American Petroleum Institute are dedicated to continuous efforts to improve the compatibility of our operations with the environment while economically developing energy resou
3、rces 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 un environmentally sound manner while protecting the health and safety of our employees and the public. T
4、o 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: PRINCIPLES e O e To recognize and to respond to community concerns about our raw materials, p
5、roducts and operations. 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. To make safety, health and environmental considerations a priority in our planning, and our
6、 development of new products and processes. 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. To counsel customers, transporters and others in t
7、he safe use, transportation and disposal of our raw materials, products and waste materials. To economically develop and produce natural resources and to conserve those resources by using energy efficiently. To extend knowledge by conducting or supporting research on the safety, health and environme
8、ntal effects of our raw materials, products, processes and waste materials. To commit to reduce overall emission and waste generation. To work with others to resolve problems created by handling and disposal of hazardous substances from our operations. To participate with government and others in cr
9、eating responsible laws, regulations and standards to safeguard the community, workplace and environment. To promote these principles and practices by sharing experiences and offering assistance to others who produce, handle, use, transport or dispose of similar raw materials, petroleum products and
10、 wastes. STD.API/PETRO PUBL Libb5-ENGL 1998 073Z290 0606748 LOT Analysis and Reduction of Toxicity in Biologically Treated Petroleum Product Terminal Tank Bottoms Water Health and Environmental Sciences Department API PUBLICATION NUMBER 4665 PREPARED UNDER CONTRACT BY: J.F. HALL TEXACO INC. B. V. KL
11、OCK R.S. PATEL ENVIRONMENTAL RESEARCH SECTION G.H. WEBSTER PORT ARTHUR, TEXAS D.C. VUONG RESEARCH and 2) the toxicants boron, barium, antimony, tin, vanadium, selenium, cyanides, surfactants, naphthenic acids, and cl8 adsorbable material. Though the test organism, Mysidopsis bahia, is an estuarine o
12、rganism tolerant of a wide range of salinities, it may not be capable of tolerating inorganic ion ratios which deviate markedly from those typical of seawater. To investigate this possibility, two acutely toxic samples were serially diluted with a mock wastewater. The mock wastewater for each sample
13、 consisted of distilled water into which was dissolved seawater ions at approximately the same concentrations as in the undiluted sample. Should ion ratios be responsible for sample toxiciy, the toxicity measured in the serially diluted samples would be proportional to the mock wastewater content. T
14、o assess the possibility of toxicity due to other toxicants, three samples were analyzed for boron, barium, antimony, tin, vanadium, selenium, cyanides, surfactants, naphthenic acids, and c18 adsorbable material. Concentrations of these consituents were compared with literature water quality and tox
15、icity threshold data. RESULTS AND CONCLUSIONS Biological treatment was observed to effectively remove metals, but produced highly variable degrees of COD, total organic carbon (TOC), biochemical oxygen demand (BOD), and ammonia removal. PhysicaVchemical treatment for ammonia, copper and zinc was req
16、uired for ten of the eleven samples, and for arsenic in five of the eleven samples. Nine of the eleven samples contained residual acute toxicity (LC5,1 00% effluent) following biological treatment, metals precipitation and ammonia removal. Of the two samples not acutely toxic, one contained residual
17、 chronical toxicity (NOEClOO% effluent). Of the nine secondary effluent samples with residual acute toxicity, tertiary treatment for organics by oxidation and activated carbon was only moderately effective in reducing toxicity. Six of the samples remained acutely toxic following tertiary treatment.
18、Tertiary treatment was also ineffective in reducing the chronic toxicity of the sample not acutely toxic following secondary treatment. Two samples with residual acute toxicity following tertiary treatment for organics were examined for toxicity due to salinity ion ratios, as described above. Sample
19、 toxicity was not found to be due to salinity ion ratios. Three samples with residual acute toxicity following tertiary treatment were examined for toxicity due to the toxicants boron, barium, antimony, tin, vanadium, selenium, cyanides, surfactants, naphthenic acids, and C1 adsorbable material. Con
20、centrations of these constituents were not found to exceed literature water quality criteria or toxic thresholds for Mysidopsis bahia. It was concluded that sample toxicity was not due to any of these constituents. ES-2 STD.API/PETRO PUBL Ybb5-ENGL 1998 0732290 0bOb759 T95 D 1. INTRODUCTION OBJECTIV
21、ES The objectives of the study were to identify the degree and chemical nature of effluent toxicity in a variety of biologically treated petroleum product terminal tank bottoms water effluents and to explore techniques for cost-effectively removing the toxicity. BACKGROUND Current and anticipated re
22、gulations are placing stringent limitations on wastewater discharges from petroleum product terminals. Marketing terminal wastewater consisting of tank water bottoms and wash water from loading facilities is usually treated with an oil/water separator to remove free oil prior to discharge. This has
23、been sufficient for most terminals since they have low flow rates and minimal amounts of contaminant discharge. However, additional treatment facilities may be needed for those marketing terminals whose effluents may have potential for environmental impact (i). In assessing that potential impact, re
24、gulatory bodies are now starting to add bioassay testing to ensure that the discharged water will not be toxic to aquatic life in the receiving waters. A study of marketing terminal effluent toxicity to selected invertebrate and vertebrate test species reported 96-hour LC5o values ranging from 1 O0
25、percent effluent among terminals. Invertebrates were more sensitive to the terminal effluents than vertebrate test species. Some fraction of the total observed toxicity may have been due to water quality parameters such as hardness and salinity. However, this cannot account for all of the effluent t
26、oxicity observed in this study. It is concluded that the observed mortality was a function of the concentration of pollutant(s) in the marketing terminal effluents. A Texaco field and laboratory investigation of biological and chemical/physical wastewater treatment technologies showed that biologica
27、l treatment followed by activated carbon polishing produced the least toxic marketing terminal effluent. However, after such treatment, effluents may still be acutely toxic at the “end of pipe.” Based on these results, treated effluents would require dilution of twenty fold or more to be chronically
28、 non-toxic in receiving waters (i). An extensive investigation comparing sequencing batch reactor (SBR) and rotating biological contactor (RBC) processes concluded that these biological treatments were capable of reducing acute and chronic toxicity in marketing terminal wastewaters (2). It was also
29、determined that activated carbon treatment enhanced reduction of chronic toxicity but did not completely eliminate it. The chronic toxicity remaining after carbon treatment may have been due to the presence of ammonia, surfactants, metals andor unmeasured biorefractory organic compounds. This study
30、examines wastewaters from a variety of source terminals to examine in detail the nature of any toxicity found in petroleum product terminal tank bottoms water, and to develop practical means for removing that toxicity. 1-1 STD-API/PETRO PUBL 4bbS-ENGL 0732290 OhOb760 707 2. GENERAL APPROACH As will
31、be evident in the following discussion, this study involved the development of non- standard approaches to obtaining meaningful data on the nature and removal of toxicity. This section provides an overview of what was done in the study, how it was done, and why the particular methods were chosen. OB
32、JECTIVES The objectives of the study were to identi the degree and chemical nature of effluent toxicity in a variety of biologically treated petroleum product terminal tank bottoms water effluents and to explore techniques for cost-effectively removing the toxicity. DISCUSSION Water Source. Petroleu
33、m product terminal wastewaters can come from a variety of sources within the terminal (6), but the only source considered in this study was product tank bottoms water. That was done for the following reasons: 0 Tank bottoms water is the major source of organic material in petroleum product terminal
34、wastewaters, and is probably the major source of effluent toxicity. Tank bottoms water is the only petroleum product terminal wastewater stream inherent to the function of the facility (storage of petroleum products). Other wastewater streams are incidental. The flow of many other petroleum product
35、terminal wastewater streams, particularly those derived from storm water (general runoff and loading rack water) are highly variable. Since toxicity is concentration-dependent, dilution by these variable flows will affect combined effluent toxicity. The study was limited to tank bottoms water to eli
36、minate this source of variability. The other major source of organic material and toxicity in petroleum product terminals is detergents, which are commonly used on truck loading racks. Since detergent usage is not inherent to petroleum product terminals, it was decided to eliminate this stream from
37、the water being tested. (It should be noted, however, that a facility which has effluent toxicity problems should examine its use of detergents.) 0 0 Normalization. All of the tank bottoms waters which were used in the final testing were normalized by diluting their COD levels to 4000 mg/L prior to
38、treatment. The reasons for this are as follows: 0 The various tank bottoms water samples varied considerably in strength and thus in their inherent toxicity (since toxicity is concentration-dependent). This fact, along with the fact that tank bottoms waters are normally diluted with other terminal w
39、aste streams, implies that comparison of the toxicity of various samples is best done on the common basis of wastewater strength. It 2-1 STD.API/PETRO PUBL 9665-ENGL 1998 M 0732290 0606761 693 should be noted that factors which affect tank bottoms water strength (dilution water from product shipment
40、 or from storm water bypassing floating roof seals) are not inherent to the product storage process. COD was chosen as the basis for normalization since the BOD test is more subject to variability unrelated to wastewater composition, and since the TOC test does not detect inorganic oxygen-demanding
41、contaminants. 0 4000 mg/L COD was chosen as the normalization level based on previous testing (2) which showed this level to be typical in wastewaters from low-flow petroleum product terminals. Use of Biotreatment. The reasons for subjecting all water samples to biotreatment before toxicity analysis
42、 or furuier treatment are as follows: Petroleum product terminal tank bottoms water generally has low flow, but quite high concentrations of organic contaminants expected to be toxic to aquatic life. Thus, it is assumed that any tank bottoms water which is discharged to the environment will receive
43、biological treatment (or the equivalent) prior to discharge. There would be no point in testing the toxicity of untreated waters which would almost certainly fail the bioassay test. 0 Biological treatment is the standard type of treatment utilized for almost all domestic, commercial, and industrial
44、wastewaters bearing organic contaminants. Variety of Water Sources. As shown on Table 1, tank bottoms water samples were obtained from nine member companies at terminals in various geographical locations, and from product tanks which contained a variety of products. These samples were assumed to cov
45、er the typical range of petroleum product terminal wastewater quality variability. Causes of such variability might include: Different companies may use different crudes and different refining processes to make the finished products. Different locations may be associated with different water qualiti
46、es (for example, coastal terminals are more likely to receive products by ship, and thus more likely to have seawater contamination). Different petroleum products receive different refining processing (for example, gasolines require much different types of refining than diesel fuels). As discussed i
47、n Section 4, not all collected samples were used throughout this study; samples were removed from consideration because of low COD concentration (samples 2, 10 and 13) and dilution by atmospheric condensate (sample 14). 2-2 STD.API/PETRO PUBL 4665-ENGL 1798 O732290 0606762 5BT = Table I. Tank Bottom
48、s Water Sources ID Product Company Region Gasoline Tanks A Gulf Coast 3 Gasoline Regular Unleaded B Gulf Coast 4 Gasoline Mid-grade Unleaded C Gulf Coast 5 Gasoline Mid-grade Unleaded C Gulf Coast 6 Gasoline Super Unleaded D Gulf Coast 7 Gasoline Regular Unleaded D Gulf Coast 9 Gasoline Regular Unle
49、aded F East Coast 12 Gasoline Regular Unleaded G East Coast 15 Gasoline Super Unleaded I Midwest Fuel Oil and Diesel Tanks 8 FuelOil#2 E East Coast Il Diesel G East Coast Tank Bottoms Samples Not Used 2 Gasoline Regular Unleaded A Gulf Coast 10 Fuel Oil #2 F East Coast 13 Terminal Wastewater H Gulf Coast Gulf Coast l4 Vapor Recovery Water Gasoline Super Unleaded Reformulated (1 1% MTBE) Gasoline Super Unleaded with , TOXICITY IDENTIFICATION The method used to identify the nature of the biologically treated effluent toxicity (for those bioeffluents which are toxic) is
