Wastewater refinery

Petroleum refinery wastewater system VOC emissions (Subpart QQQ)... 

Certain refinery wastewater streams are treated separately, prior to the wastewater treatment plant, to remove contaminants that would not easily be treated after mixing with other wastewater. One such waste stream is the sour water drained from distillation reflux drums. Sour water contains dissolved hydrogen sulfide and other organic sulfur compounds and ammonia which are stripped in a tower with gas or steam before being discharged to the wastewater treatment plant. 

The following data were obtained from a pilot adsorption test for refinery wastewater, where the concern is for COD removal. Develop the breakthrough curves for this process. 

With the addition of appropriate additives as needed, the flotation of refinery wastewaters reduced their oil content to less than 10 mg/L in pilot-plant operation [Steiner, Bennett, Mohler, and Clere, Chem. Eng. Prog, 74(12), 39 (1978)] and full-scale operation (Simonsen, Hydrocarh. Process. Pet. Refiner, 41(5), 145, 1962]. Experiments with a cationic collector to remove oils reportedly confirmed theory [Angelidon, Keskavarz, Richardson, and Jameson, Ind. Eng. Chem. Process Des. Dev., 16, 436 (1977)]. 

Petroleum refinery wastewater treatment sludges (F037 and F038)... 

Guimaraes C, Porto P, Oliveira R, Mota M (2005) Continuous decolourization of a sugar refinery wastewater in a modified rotating biological contactor with phanerochaete chrysos-porium immobilized on polyurethane foam disks. Process Biochem 40 535-540... 

Table 5 Variability study along a refinery wastewater network [2]...

Except for the development of on-line systems for nutrients monitoring, the measurement of other inorganic non-metallic constituents is rather rare. Some commercial systems based on electrochemical sensing are proposed for the measurement of cyanide. A simple and rapid procedure for sulphide measurement in crude oil refinery wastewater has been developed [ 32 ]. Based on the de-convolution of the UV spectrum of a sample, this method has a detection limit of 0.5 mg L 1 and has been validated for crude oil refinery wastewater. 

Proceedings of the Second Open Forum on Management of Petroleum Refinery Wastewater," Environmental Protection Agency, EPA 600/2-78-058, March 1978. 

Pfeffer FM. 1979. The 1977 screening survey for measurement of organic priority pollutants in petroleum refinery wastewaters. ASTM Spec Tech Publ, 181-190. 

Surfactants entering the refinery wastewater streams will increase the amount of emulsions and sludge generated. Surfactants can enter the system from a... 

Forty-five priority pollutants are manufactured as final or intermediate materials 15 of these are manufactured at single refineries. Benzene, ethylbenzene, phenol, and toluene are manufactured by at least 10% of all refineries. Of all refineries, 8% manufacture cyanides, while more than 20% manufacture benzene and toluene. Hence, priority pollutants are expected to be present in refinery wastewaters. The EPA s short-term and long-term sampling programs conducted later detected and quantified 22 to 28 priority pollutants in refinery effluent samples [5]. 

Conventional refinery wastewater treatment technology is mainly concerned with removing oU, organics, and suspended solids before discharge. However, because of new stringent discharge requirements for specific toxic constituents as well as whole-effluent toxicity, specific advanced treatment processes are becoming a necessity for many refineries. This section describes the... 

The API separator is a widely used gravity separator for removal of free oil from refinery wastewater. It can be installed either in the central wastewater treatment plant or as an upstream pretreatment process to remove gross quantities of free oil and solids. 

Dissolved air flotation in combination with flocculation can reduce oil content in refinery wastewater to levels approaching oil solubility [40]. According to Katz [41], DAF plus chemical aids for flocculation can be expected to reduce BOD and COD by 30-50% and to reduce total oil to the range 5-25 mg/L. Table 17 shows some data for oil removal from refinery wastewater [27]. Removal efficiencies range from 70 to 90%. The accepted design overflow rates for DAF units are between 60 and 120 L/min per square meter (1.5-3.0 gpm/sq ft) [17]. 

Activated sludge is the most common biological treatment process because of the high rate and degree of organic stabilization possible. It is widely used in treating refinery wastewater [5]. 

Other variations of activated sludge such as deep shaft high-rate activated sludge and sequencing batch reactor (SBR) have been used for refinery wastewater treatment. A refined deep shaft process has been installed and in operation at the Chevron refinery in Burnaby, British Columbia, Canada, since 1996 [45]. In the course of a recent wastewater treatment upgrade, a BP refinery on the eastern Australian coast converted an existing lagoon to an SBR system [46]. 

The petroleum industry uses them mostly as roughing devices to reduce the loading on activated sludge systems. In some cases, trickling filters are used to pretreat steam-stripped sour water before mixing it with other refinery wastewater streams for secondary treatment [48]. 

Several advanced filtration systems are finding applications in treating refinery wastewaters. Examples include the HydroClear filter (Zimpro, Rothschild, WI) and the Dynasand filter (Parkson Corporation, Fort Lauderdale, FL). The HydroClear filter employs a single sand medium (0.35-0.45 mm) with an air mix (pulsation) for solids suspension and regeneration of the filter surface. Filter operation enables periodic regeneration of the medium... 

Many refineries in the United States are being required to control whole-effluent toxicity as well as specific toxic constituents to meet new wastewater discharge limits. There can be a variety of toxic constituents that may need to be controlled, depending on waste characteristics and local water quality objectives. The more common constituents in refinery wastewater include cyanide and heavy metals. The treatment processes for control of whole-effluent toxicity, cyanide, and heavy metals are discussed below. 

Reverse osmosis can remove dissolved metals to very low levels. It can also remove a variety of pollutants such as cyanide and residual organics from refinery wastewater. However, because it is an expensive process, it would be competitive only if removal of total dissolved solids is also required. It also requires extensive pretreatment to prevent membrane fouling and deterioration [52]. The pretreatment processes may include filtration to remove suspended solids, pH adjustment, softening, and activated carbon treatment to remove organics and chlorine. A major drawback of the RO process is the handling and disposal of the reject stream, which can amount to 20-30% of the influent flow. 

Since 1990, several new or revised U.S. environmental regulations, which significantly affect refinery wastewater treatment systems, have been promulgated. The most important ones include the revised Toxicity Characteristics (TC) rule, the Primary Sludge rule, and the Benzene NESHAP (National Emissions Standards for Hazardous Air Pollutants) rule. These regulations and their impacts on refinery wastewater facilities are briefly discussed below. 

Figure 21 Refinery wastewater recycle/zero liquid discharge scheme. Pretreatment and reverse osmosis are used to recycle water, and brine concentrator and crystallizer are used to treat the rejects to achieve zero liquid discharge. (From Ref. 78.)...

Ford, D.L. Manning, F.S. Treatment of petroleum refinery wastewater. In Carbon Adsorption Handbook Cheremisinoff, P.N., Ellerbusch, F., Ed. Ann Arbor Science Ann Arbor, Ml, 1978. Patterson, J.W. Industrial Wastewater Treatment Technology, 2nd Ed. Butterworth Boston, 1985. Hutton, D.G. Robertaccio, F.L. Waste water treatment process. U.S. Patent 3,904,518, September 9, 1975. 

Rizzo, J.A. Case history Use of powdered activated carbon in an activated sludge system. First Open Forum on Petroleum Refinery Wastewaters, Tulsa, OK, 1976. 

Nurdogan, Y. Schroeder, R.P. Meyer, C.L. Selenium removal from petroleum refinery wastewater. Proceedings, 49th Purdue Industrial Waste Conference, West Lafayette, IN, 1994. 

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