Effluent, sewage waste water

TRADE EFFLUENT Any waste water released from an industrial process or trade premises with the exception of domestic sewage. 

Collection of a representative sample as BOD tests are often carried out on sewage effluents and waste-water that are likely to be inhomogeneous, care should be taken to ensure the sample is as representative as possible. 

The most widespread biological application of three-phase fluidization at a commercial scale is in wastewater treatment. Several large scale applications exist for fermentation processes, as well, and, recently, applications in cell culture have been developed. Each of these areas have particular features that make three-phase fluidization particularly well-suited for them Wastewater Treatment. As can be seen in Tables 14a to 14d, numerous examples of the application of three-phase fluidization to waste-water treatment exist. Laboratory studies in the 1970 s were followed by large scale commercial units in the early 1980 s, with aerobic applications preceding anaerobic systems (Heijnen et al., 1989). The technique is well accepted as a viable tool for wastewater treatment for municipal sewage, food process waste streams, and other industrial effluents. Though pure cultures known to degrade a particular waste component are occasionally used (Sreekrishnan et al., 1991 Austermann-Haun et al., 1994 Lazarova et al., 1994), most applications use a mixed culture enriched from a similar waste stream or treatment facility or no inoculation at all (Sanz and Fdez-Polanco, 1990). 

The high amounts in which these substances are consumed and produced have conferred illicit drugs and their human metabolites a pseudo-persistent character in the environment. Like over-the-counter and prescribed pharmaceuticals, illicit drugs are metabolized after consumption and different proportions of the parent compound and metabolic by-products are excreted via urine or feces and flushed into the sewage system toward wastewater treatment facilities, if existing. However, these substances are poorly or incompletely removed by conventional waste-water treatment processes [2, 3]. As a consequence, illicit drugs and metabolites are continuously introduced via wastewater treatment plant (WWTP) effluents into the aquatic media. In fact, this constitutes the main route of entry of this type of compounds into the environment as direct disposal is unlikely. 

For a detailed discussion the reader is referred to a number of recent monographs [9,10,23] and review articles [50,226-231]. The role of electrochemistry in waste water and effluent treatment is still queried, as remarked by Pletcher and Walsh [10]. One answer would be, relatively small since there are many competitive methods which are cheaper on a large scale and use less energy. Principle types of processes used in local-authority sewage works are listed in Table 14. 

Phenol has been detected in the effluent discharges of a variety of industries. It was found in petroleum refinery waste water at concentrations of 33.5 ppm (Pfeffer 1979) and 100 ppb (Paterson et al. 1996), in the treated and untreated effluent from a coal conversion plant at 4 and 4,780 ppm, respectively (Parkhurst et al. 1979), and in shale oil waste water at a maximum of 4.5 ppm (Hawthorne and Sievers 1984). It has also been detected in the effluent from a chemical specialties manufacturing plant at 0.01-0.30 ppm (Jungclaus et al. 1978), in effluent from paper mills at 5-8 ppb (Keith 1976 Paterson et al. 1996), and at 0.3 ppm in a 24-hour composite sample from a plant on the Delaware River, 2 and 4 miles downriver from a sewage treatment plant (Sheldon and Hites 1979). 

Over the last years, a renewed interest on the antibiotic resistance phenotypes in municipal waste water treatment plants became apparent in the scientific literature. The underlying hypothesis of these smdies is that urban sewage treatment plants are potential reservoirs of antibiotic resistance, and, in general, it is aimed at contributing to assess the risks of dissemination, posed by the treated effluents discharged into natural water courses. As a general trend, these studies focus on human/animal commensal and environmental bacteria, frequently disseminated via faecal contamination, and which can survive in waters. The relevance of these bacteria, which may exhibit clinically relevant resistance phenotypes, as possible nosocomial agents seems also to be a motivation behind these smdies. 

Waste water treatment is accompanied by bacterial community rearrangements which may lead to changes (increases or decreases) of the percentages of antimicrobial-resistant bacteria in the final effluent when compared with the raw inflow. Additionally, sewage treatment offers privileged conditions to favour antibiotic resistance acquisition and/or selection (see Sect. 3). Although some authors reported significant decreases of resistance to aminopenicillins (presumptive Acinetobacter and Enterobacteriaceae), cephaloporins (Acinetobacter) and... 

In the past few years the use of rotifers in ecotoxicological studies has substantially increased. The main endpoints used are mortality, reproduction, behavior, cellular biomarkers, mesocosms, and species diversity in natural populations [126]. Several workers have used Brachionus calyciflorus for various types of toxicity assessments. Thus, comprehensive evaluation of approximately 400 environmental samples for the toxicity assessment of solid waste elutriates, monitoring wells, effluents, sediment pore water, and sewage sludge was carried out by Persoone and Janssen [127]. The mortality of rotifers hatched from cysts is evaluated after 24 hours exposure. This microbiotest has been commercialized in a Rotoxkit F [128,129]. 

Most reports that document the removal of PPCPs during the treatment of waste-water or sewage are based on measurements of the concentration in the influent and effluent (Ternes, 1998). Based on such studies, it is generally apparent that the average elimination of PPCPs from such environmental matrices can be quite variable not only between different compounds but also within the same compound when present in different matrices. Such tremendous differences in the removal of PPCPs are not entirely surprising as these compounds are quite heterogeneous in... 

Lester JN. 1983. Significance and behavior of heavy metals in waste water treatment processes 1. Sewage treatment and effluent discharge. Sci Total Environ 30 1-44. 

Optimum chromatographic conditions are summarised in Table 4.12. The methods of Sakurai et al. [322] and Morgan and Danielson [323] are both applicable to the analysis of waste waters and sewage effluents. 

The free floating aquatic plant, Eichhomia crassipes (MART.) Solms, the water hyacinth, is a highly prolific weed that infests many waterways in the southern USA, Africa and Asia. This plant has the ability to take up metals from solution and to reduce BOD, and has been used successfully to treat lagoon effluent and sewage waste (Wolverton and McDonald, 1979 Haider et al., 1984 Farago and Parsons, 1985 Nor, 1990). It appears to be one of the most generally tolerant plants known and can also be used to assess contamination in water (Farago et al., 1989). 

---