Piloting During a Pandemic

Occurrence and spatio-temporal variability of halogenated acetaldehydes in full-scale drinking water systems

Trantham, J.C., SPE-AIME, Phillips Petroleum Co. Phillips Petroleum Co. Patterson Jr., H.L., SPE-AIME, Patterson Jr., H.L., SPE-AIME, Phillips Petroleum Co. Phillips Petroleum Co. Boneau, D.F., SPE-AIME, Phillips Petroleum Co. Phillips Petroleum Co. JULY 1978 Careful control of fluid rates, injection pressures, volumetric balance, and quality control of injected chemical solutions are key factors in chemical flooding in the fractured, oil-wet North Burbank Unit reservoir. Fluid diversion treatments based on radioactive tracer studies helped maintain reservoir control. After 18 months of operation, pilot performance is encouraging. performance is encouraging. Introduction Fresh-water preflush injection began in the North Burbank Unit surfactant/polymer pilot in Osage County, Okla., on Dec. 1, 1975. This was followed by a sequence of slugs, including controlled salinity preflush, surfactant solution, and a graded viscosity-mobility buffer that is now about 60 percent complete. A description of the oil recovery process was presented in an earlier paper. This study reports the field operations involved when mixing and injecting the fluids, control of fluid composition, efforts to optimize the movement of fluids within the reservoir, and techniques used when analyzing the progress of the pilot's different phases for the past 19 months. Pilot Layout and Equipment Pilot Layout and Equipment Pilot Pattern and Water Supply Pilot Pattern and Water Supply The pattern (Fig. 1) was composed of an array of nine inverted five-spots of approximately 10 acres each (5 acres/well). Injection wells were fed by two gas-driven, triplex pumps located at the flow station adjacent to the chemical blending building at the southwest corner of the tract. Fresh water used for preflushing and for preparing all chemical solutions was obtained from wells completed in the alluvium of the Arkansas River. The only required treatment of the supply water was the addition of a corrosion inhibitor at the water supply station. An oxygen scavenger also was added to assure that no oxygen was present to form iron-containing corrosion products that would plug the formation and interfere with the products that would plug the formation and interfere with the oil-displacing chemical processes. The water contained about 1,000 ppm total dissolved solids, including less than 100 ppm total hardness. This contrasted strongly with the 80,000-ppm (total solids) formation water that allowed fresh-water production to be used as a continuously injected tracer for supplementing the radioactive tracers. Equipment Fig. 2 shows a simplified flow diagram of the chemical blending system. Three basic assemblies make up this system: the brine maker, the surfactant blender, and the polymer mixing system. Air was excluded from all three polymer mixing system. Air was excluded from all three of the chemical mixing systems, using a nitrogen blanket. Brine Maker. A brine averaging 31-weight-percent sodium chloride was prepared continuously by percolating fresh water through a bed of salt crystals. percolating fresh water through a bed of salt crystals. This concentrated solution was blended to the desired concentration by a proportioning pump that injected it into the fresh water fed to the injection pumps or to the surfactant blender. The concentrated brine varied no more than +/- 1 weight percent in concentration. This system was used during the injection of saline preflush and surfactant blending. P. 1068

The Wastewater Treatment Plant (WWTP) of Frederikshavn, Denmark, was extended in the early nineties to increase its average daily flow to 4,5 MGD (16,500 m³/d) and meet new requirements for nutrient removal (8 mg/l TN, 1,5 mg TP/l). A parallel biological aerated filter (BAF) was the selected as the most economical upgrade of the existing activated sludge plant (AS), and started up in 1995. Running two full scale processes in parallel on the same wastewater and treatment objectives for over ten years enabled a direct comparison in relation to operating performance, costs and experience. After screening, a combined grit and grease chamber and 3 primary settlers, the effluent is pumped to the bio-treatment, consisting of AS with recirculation (Modified Lutzack-Ettinger – MLE) and an upflow BAF with floating media. The wastewater is a mixture of industrial and domestic wastewater, with a dominant discharge of fish processing effluent which can amount to 50 % of the flow. The maximum hydraulic load on the pretreatment section as a whole is 10 MGD (1,530 m3/h) . Approx. 60% of the sewer system is combined with a total of 32 overflow structures. To avoid the direct discharge of combined sewer overflows into the receiving waters, the total hydraulic capacity of the plant is increased during rain to 27 mgd (4,330 m³/hour) or 6 times average flow. During rain, this is achieved by directing some of the raw sewage through a stormwater bypass to the BAF and switching all six BAF to full nitrification. After final biotreatment, the wastewater is conveyed through a 500 m sea outfall. The operation of the BAF can be modified to accommodate various treatment needs: - either using simultaneous nitrification/denitrification in all filters with recirculation - bottom aeration with full nitrification in all filters for stormwater treatment - or post-denitrification in 1 filter. On-line measurements for the parameters NO3, NO2, NH4 and PO4 as well as dissolved oxygen (DO) are used for control of aeration and for addition of flocculants for P-removal and external carbon source (methanol). The BAF backwash sludge, approx. 0.5 MGD (1.900 m³/d) once every 24 h in dry weather, is redirected to the AS plant. Sludge from primary settlers and the combined biosolids from the AS plant are anaerobically digested, with methane gas being used for generation of heat and power. This paper discusses the experience gained from the plant operation during the last ten years, compiling comparative performance and cost data of the two processes.

Wastewater treatment systems are characterized by large temporal variability of inflow, variable concentrations of components in the incoming wastewater to the plant, and highly variable biological reactions within the process. The behavior of observed process variables within a wastewater treatment plant (WWTP at a certain time instant is the combined effect of various processes initiated at different moments in the past. This is called a time-delay effect in the system. Due to the nature of strong nonlinear mapping, neural networks provide advantages as a modeling and identification tool over a structure-based model. However, the determination of the architecture of the artificial neural networks (ANNs) and the selection of key input variables with a time delay is not easy. in our research, a genetic adapted time-delay neural network (GATDNN), which is a combination of time-delay neural network(TDNN) and genetic algorithms(GAs), was developed and applied to the full-scale Bardenpho advanced sewage treatment process. In a GATDNN, a three-step modelling procedure was performed: (1) selection of significant input variables to maximise the predictive accuracy for each specific output; (2) finding a suitable network topology for the ANN-based process estimator; (3) sensitivity analysis. The results demonstrate that the modelling technique presented using a GATDNN provides a valuable tool for predicting the outputs with high levels of accuracy and identifying key operating variables. This work will permit the development of a reliable control strategy thus reducing the burden of the process engineer.

Treatment of poly- and perfluoroalkyl substances in U.S. full-scale water treatment systems

Morphotype-resolved characterization of microalgal communities in a nutrient recovery process with ARTiMiS flow imaging microscopy.

Fate of cefotaxime-resistant Enterobacteriaceae and ESBL-producers over a full-scale wastewater treatment process with UV disinfection

At eight full-scale water treatment plants in the Netherlands the removal of spores of sulphite-reducing clostridia (SSRC) was determined. By sampling and processing large volumes of water (1 up to 500 litres) SSRC were detected after each stage of the treatment. This enabled the assessment of the removal efficiency of the full-scale unit processes for persistent micro-organisms. A comparison with literature data on the removal of Cryptosporidium and Giardia by the same type of processes revealed that SSRC can be considered as a potential surrogate. The average Decimal Elimination Capacity (DEC) of the overall treatment plants ranged from 1.3–4.3 log. The observed actual log removal of SSRC by the unit processes and the overall treatment at one of the studied locations showed that the level of variation in removal efficiency was approximately 2 log. Moreover, from the actual log removal values it was observed that a low SSRC removal by one unit process is partly compensated by a higher removal by subsequent unit processes at this location. SSRC can be used for identification of the process conditions that cause variation in micro-organism removal which may lead to process optimization. Further research is necessary to determine the optimal use of SSRC in water quality monitoring for the production of microbiologically safe drinking water.

The simultaneous chemical phosphorus removal (SCPR) process has been widely applied in wastewater treatment plants (WWTPs) due to the high phosphorus removal efficiency through the synergy of biological and chemical phosphorus removal (BPR and CPR). However, phosphorus removal reagents could affect the bacterial community structure in the SCPR system and further affect the BPR process. The BPR phenotypes and community structures in the SCPR system, especially the population of polyphosphate-accumulating organisms (PAOs), are not completely clear. In order to clarify these problems, the phosphorus removal performance and the PAO population in a full-scale SCPR system were investigated. Results showed that diverse PAOs still existed in the SCPR system though the BPR phenotypes were not observed. However, the relative abundances of Accumulibacter and Tetrasphaera, the two most important genera of PAOs, were only 0.59% and 0.20%, respectively, while the relative abundances of Competibacter and Defluviicoccus, two genera of glycogen-accumulating organisms (GAOs), were as high as 5.77% and 1.28%, respectively. Batch tests showed that PAOs in the SCPR system still had a certain polyphosphate accumulating metabolic activity, which could gradually recover after stopping the addition of chemical reagents. This study provided a microbiological basis for the SCPR system to recover the enhanced biological phosphorus removal (EBPR) performance under suitable conditions, which could reduce the dosage of chemical reagents and the operational cost.

Sludge dewatering and stabilization in drying reed beds: Characterization of three full-scale systems in Catalonia, Spain

Moving bed biofilm reactor (MBBR) systems are increasingly used for municipal and industrial wastewater treatment, yet in contrast to activated sludge (AS) systems, little is known about their constituent microbial communities. This study investigated the community composition of two municipal MBBR wastewater treatment plants (WWTPs) in Wellington, New Zealand. Monthly samples comprising biofilm and suspended biomass were collected over a 12-month period. Bacterial and archaeal community composition was determined using a full-cycle community approach, including analysis of 16S rRNA gene libraries, fluorescence in situ hybridization (FISH) and automated ribosomal intergenic spacer analysis (ARISA). Differences in microbial community structure and abundance were observed between the two WWTPs and between biofilm and suspended biomass. Biofilms from both plants were dominated by Clostridia and sulfate-reducing members of the Deltaproteobacteria (SRBs). FISH analyses indicated morphological differences in the Deltaproteobacteria detected at the two plants and also revealed distinctive clustering between SRBs and members of the Methanosarcinales, which were the only Archaea detected and were present in low abundance (<5%). Biovolume estimates of the SRBs were higher in biofilm samples from one of the WWTPs which receives both domestic and industrial waste and is influenced by seawater infiltration. The suspended communities from both plants were diverse and dominated by aerobic members of the Gammaproteobacteria and Betaproteobacteria. This study represents the first detailed analysis of microbial communities in full-scale MBBR systems and indicates that this process selects for distinctive biofilm and planktonic communities, both of which differ from those found in conventional AS systems.

ConocoPhillips is committed to creating a responsible water management plan in developing assets in the Permian Basin of West Texas. Sourcing water for the large multi-frac stimulations in West Texas is a well-known constraint on oil and gas development activities in the area. Additionally, large volumes of produced water (PW) have traditionally required clean up and disposal in injection wells. Rather than viewing these constraints only as challenges, ConocoPhillips realizes the tremendous opportunity to address both issues by treating and reusing PW for hydraulic fracturing operations. With this perspective, water management strategy development has become a truly collaborative, cost-effective, and integrated process that addresses the full life-cycle of water. ConocoPhillips executed a multi-well reuse pilot program in the Permian Basin. A "fit-for-purpose" treatment scheme was deployed to selectively remove free oil, suspended solids, hydrogen sulfide, and iron as well as to inactivate microorganisms. While gravity separation was adequate for de-oiling and filtration for suspended solids, oxidation followed by coagulation and clarification was necessary for dissolved iron removal. The treated water iron concentration was below 5 mg/L whereas the turbidity was consistently below 10 NTU, making it suitable for well completions. When treating for H2S removal, the oxidation followed by filtration method was sufficient to reduce the H2S concentration to &amp;lt;0.2 mg/L and achieve turbidity below 10 NTU. The treated PW was compatible with the new salt-tolerant friction reducer, achieving similar friction reduction compared to a standard friction reducer and fresh water. The treated PW used in hydraulic fracturing was also compatible with formation water as it was produced from the same formation. The sulfate reducing bacteria were non-detectable in the treated water after four weeks of storage. The six month pilot operation, demonstrated that PW reuse is technically feasible and can be a cost-effective solution compared to other available water sourcing alternatives. The technical approach developed allowed use of salty produced water (&amp;gt;220,000 mg/L TDS) for completion activities utilizing a new type of friction reducer. Based on the success of the pilot program, a full-field produced water reuse program has been initiated early in the appraisal and development phase of the project to reduce implementation risks and improve economics in a safe and environmentally responsible manner. Strong collaboration led to success in these projects, and they were designed and executed through a significant team effort made by completion engineers, water treatment engineers, the asset development team, and the operations team. This paper provides an overview of the plan implemented for safe pilot operation, procedures for treatment of produced water and water quality results.

Metagenomic Insight Reveals the Microbial Structure and Function of the Full-Scale Coking Wastewater Treatment System: Gene-Based Nitrogen Removal

Low temperatures can result in start-up and operational problems in wastewater treatment plants. The microbial community structures of three full-scale biological processes for municipal wastewater treatment, namely, anoxic-oxic activated sludge (A/O) process, oxidation ditch, and sequencing batch reactor, in winter and spring were investigated. The performances of the three biological processes were all stable during winter and spring. Comparing all three plants, the NH(4) (+)-N removal efficiency using the A/O process was found to be the highest during both winter and spring. According to the similarity coefficient of the polymerase chain reaction and denaturing gradient gel electrophoresis analysis determined via the culture-independent method, the microbial community structure is the most stable using the A/O process at different temperatures. The dominant members primarily belonged to Proteobacteria, Nitrospira, and Bacteroidetes. In addition, Proteobacteria was the dominant member in the activated sludge utilizing peptone, glucose, and fatty acid. Compared with other biological processes, the A/O process was superior at low temperatures based on its pollution removal performance and stable microbial community sturcture.

Effects of soluble and particulate substrate on the carbon and energy footprint of wastewater treatment processes