Liquid Process Streams Research Articles

Microalgae: a sustainable adsorbent with high potential for upconcentration of indium(iii) from liquid process and waste streams

Unmodified microalgal biomass grown on wastewater works as an effective and selective indium biosorbent even at low pH values.

Commissioning of a novel in-line rheometery system in a wastewater treatment plant for more efficient polymer dosing

Urbanisation is putting enormous pressure on wastewater treatment plant facilities. Optimising the liquid and sludge process streams in existing plants is one way of prolonging the life span of such installations. Many Wastewater treatment plants (WWTP) have sludge dewatering installations where treated wastewater sludge is dewatered using belt filter presses amongst others, before final disposal. One of the most expensive inputs in these plants is the polymers used as flocculants. Controlling the optimum dosing in the dewatering process cannot currently be done in real-time. It has been shown that huge savings can be made by optimising the dosing rates of polymers based on the sludge rheology.An Ultrasound Velocity Profiling (UVP) and pressure drop (PD) measurement system was specially designed and commissioned for a WWTP. The system was installed in a WWTP to measure the rheological properties of sludge in-line and in real-time prior to mechanical dewatering using a belt filter press. This non-invasive in-line system was able to accurately measure the rheological parameters in real-time in a 100 mm stainless pipe. It was shown for the first time what the maximum in-line yield stress is that is required for optimum dewatering based on a relationship determined between the yield stress and the total suspended solids in the filtrate exiting the belt filter press.

Mechanical dewatering and water leaching pretreatment of fresh banagrass, guinea grass, energy cane, and sugar cane: Characterization of fuel properties and byproduct streams

Tropical biomass feedstock candidates, banagrass (Pennisetum purpureum×Pennisetum glaucum), guinea grass (Panicum maximum), energy cane (Saccharum spontaneum), and sugar cane (Saccharum officinarum L.) (as reference) were harvested and processed using pressing and leaching techniques to improve fuel properties for thermochemical conversion. Test results are reported that summarize the impacts of treatment methods on fuel properties and provide detailed data on mass and element partitioning between process streams to inform system design. The processed fuels had lower ash contents, improved heating values, higher ash deformation temperatures, and higher volatile matter to fixed carbon ratios than the parent materials. The liquid streams generated by the process were characterized for chemical oxygen demand, sugar content, total solids, total suspended solids, and major and trace elements. At least 20% of the initial fuel dry matter was partitioned to the byproduct liquid streams as total solids under the combined influences of leaching and mechanical processing. Analytical results support the land application of liquids as a nutrient recycling option. Element partitioning between solid and liquid process streams was determined and material and element mass balances were performed. Chemical equilibrium calculations based on the elemental composition of the parent materials and processed fuels and steam gasification conditions predicted substantial reductions in concentrations of K, Cl, S, Na, and Mg in the product gas.

Evolution of water chemistry during Marcellus Shale gas development: A case study in West Virginia

Hydraulic fracturing (HF) has been used with horizontal drilling to extract gas and natural gas liquids from source rock such as the Marcellus Shale in the Appalachian Basin. Horizontal drilling and HF generates large volumes of waste water known as flowback. While inorganic ion chemistry has been well characterized, and the general increase in concentration through the flowback is widely recognized, the literature contains little information relative to organic compounds and radionuclides.This study examined the chemical evolution of liquid process and waste streams (including makeup water, HF fluids, and flowback) in four Marcellus Shale gas well sites in north central West Virginia. Concentrations of organic and inorganic constituents and radioactive isotopes were measured to determine changes in waste water chemistry during shale gas development.We found that additives used in fracturing fluid may contribute to some of the constituents (e.g., Fe) found in flowback, but they appear to play a minor role. Time sequence samples collected during flowback indicated increasing concentrations of organic, inorganic and radioactive constituents. Nearly all constituents were found in much higher concentrations in flowback water than in injected HF fluids suggesting that the bulk of constituents originate in the Marcellus Shale formation rather than in the formulation of the injected HF fluids. Liquid wastes such as flowback and produced water, are largely recycled for subsequent fracturing operations. These practices limit environmental exposure to flowback.

Catalysis for the Valorization of Low-Value C-Streams

The need for a better carbon management and the reduction of CO2 emissions push away from the linear-carbon economy (LCE) towards a better carbon management including carbon recycling (CR). This implies the utilization of gaseous and liquid process streams so far under-utilized, and often either sent to combustion or disposed of. In this paper, four cases are discussed, namely: low-alkane streams, industrial CO2, ligno-cellulosic waste and salty-watery-glycerol. The role of catalysis in the valorization of such C-sources is discussed and examples of innovative processes are presented.

All-purpose automatic strainer

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Carbohydrate-derived chlorinated compounds in ECF bleaching of hardwood pulps: formation, degradation, and contribution to AOX in a bleached kraft pulp mill.

Five monochlorinated compounds derived from glucuronoxylan were identified in the liquid process streams of a kraft pulp mill producing hardwood pulp with ECF bleaching, representing ca. 15-20% of the AOX of the bleaching filtrates. The environmental risk of such compounds is negligible because a major fraction (70-80%) is degraded during effluent mixing and neutralization, and about 20-30% is degraded during the biological treatment of the mixed effluent. Only less than 3.5% (0.009-0.017 kg/ tAD) of the compounds formed in the bleaching leave the mill in the final effluent.

Quantitation of trace components in liquid process streams by direct liquid sampling mass spectrometry.

This paper describes the development of a liquid sampling approach for trace analysis by electron impact ionization magnetic sector mass spectrometry, with no chromatographic separation. Development of a liquid sample introduction interface based on the principle of Programmable Temperature Vaporizing (PTV) GC injection is shown. A univariate procedure for the analysis of trace (mg kg(-1)) propanoic acid in acetic acid was developed. Results from the laboratory-based analysis of acetic acid are presented and compared with conventional GC analysis. The detection limit was 16 mg l(-1) and the speed of analysis was employed to acquire 30 scans per minute thus reducing the confidence intervals of the results and potentially allowing production plants to run much closer to sales specifications. For the analysis of more complex samples where the analytes contained no unique ions, multivariate analysis was employed and up to three scans per minute were acquired. Results from the analysis of an ester for six trace impurities are shown. Calibration was by partial least squares regression. The detection limits for these components were 20-30 mg kg(-1), well within the required product specifications. The system proved to be robust and easy to operate, with analyses being carried out over a period of several months requiring no maintenance of the spectrometer and only cleaning of the injection liner of the PTV injector on a monthly basis.

Desorption of a fixed-bed adsorber by ultrasound

Adsorption processes offer the possibility to remove trace impurities of liquid process streams. An important step in adsorption processes is the regeneration of the adsorbent as it does not only affect the adsorption–desorption cycle but also the expenses of the following process steps. In this study, various desorption experiments of a loaded polymeric resin have been conducted. They were performed with cold and hot water as well as with ultrasound at different frequencies and intensities. The results indicate, that an important factor of ultrasound enhanced desorption is the temperature rise due to ultrasonication. But as regeneration is more effective at higher frequencies even though temperatures inside the column are lower, another ultrasonic effect occurs during ultrasonic desorption.

Comparison of total vaporisation and dynamic headspace techniques combined with direct mass spectrometric detection for the on-line analysis of liquid process streams

A comparison of dynamic gas purging headspace–mass spectrometry and total vaporisation–mass spectrometry for the on-line analysis of liquid process streams was made. The detection limits (3ς) for acetone in an aqueous matrix for the dynamic headspace and total vaporisation techniques are 0.4 and 11.2 µl ml–1, respectively. The relative standard deviations for the determination of 100 µl ml–1 and 10% aqueous acetone solutions, respectively, are 9.5 and 1.9% for the dynamic headspace technique and 4.4 and 3.7% for the total vaporisation technique. Analysis frequencies of 20 and 60 h–1 were achieved for the dynamic headspace and total vaporisation techniques, respectively. An accurate analysis of acetone present in an 11 component process sample was achieved using the total vaporisation technique. The complexity of the sample matrix did not allow an accurate analysis to be performed using the dynamic headspace technique.

Novel techniques for the off-line analysis of liquid process streams by mass spectrometry

Two novel methods for the analysis of simulated liquid process streams are described; static headspace analysis–MS and total vaporization–MS. A variety of experimental parameters have been studied and optimized for the detection of acetone and methyl iodide in water and acetic acid matrices, respectively. The detection limits (3σ) for the headspace technique at a sample temperature of 71 °C are 0.5 and 2 µg ml–1 and for the total vaporization technique are 19 and 1 µg ml–1, respectively, for acetone and methyl iodide. The RSD for concentrations of 10 µg ml–1 of the above analytes are generally less than 6%[n= 6 (static headspace method), n= 10 (total vaporization method)].

Membrane extraction mass spectrometry for the on-line analysis of gas and liquid process streams

A membrane extraction maw spectrometry (MEMS) tech& que was developed for the on-line analyrk of organlc components of multiple liquid and gas dreams. Sllkone hollowfiber “branos allow for the extrcrctkn of orgalc chedcdr from compkx ad dMy matrices wtth no sampk preparrdkn. MWpk dreams of both air ad water were analyzed orrllne wlth a dngk analyzer. TM6 method has been appUed In an aerobic blologlcal wastewater treatment process. Maw balance determinations were performed by quantltatlvdy measuring HH organlc contaminants In tha lnfiumt wastewater dream, In the effluent water stream, and In the effluent air stream.

On-line determination of sulphite in brine by flow-injection analysis

A spectrophotometric flow-injection procedure for the determination of sulphite in aqueous media over the range 0.5–20 mg 1 −1 is described. The reagent used was the organic disulphide 5,5′-dithiobis(2-nitrobenzoic acid). Results are presented for a laboratory-based method for sulphite in water and a potential on-line method for sulphite in high ionic strength potassium chloride brine. The general attractions of flow-injection-based monitors for the on-line analysis of liquid process streams are also discussed.

Critical Aspects in Development of Whey Protein Concentrate

Production of whey protein concentrates has increased significantly in the United States in recent years. This may be attributed mainly to greater effort on the part of whey producers to abide by pollution regulations and to availability of improved ultrafiltration membranes and equipment. The objective of this paper is to discuss certain marketing and technical aspects of whey processing that are critical for establishment of a successful commercial whey protein concentrate operation. Marketing aspects are identification of viable and specific markets, setting of specifications for whey protein concentrate, and price functionality interrelationships. Technical aspects are whey source, whey pretreatment, ultrafiltration membrane performance, characterization of liquid process streams, characterization of whey protein concentrates, application of whey protein concentrates, and effluent stream utilization. Functional whey protein concentrates produced under strict quality control conditions could find a growing market and could be used as key ingredients in development of new food products.

Current developments in on-line mass spectrometry

In recent years mass spectrometry has become increasingly accepted as an on-line analytical tool. The now proven advantages of speed, flexibility, precision and reliability have led to a whole number of applications. Purpose built instrumentation has become available and greatly improved the credibility of the technique. Recent results show the excellent long and short term precision achievable and the much improved time between required calibration. Modern computer techniques together with the availability of less expensive hardware have mede the integration of the instrumentation into the total analytical package much easier. The selectivity of the technique has been improved by, for example, the use of programmable electron energies. Sampling, for so long a problem with this technique as for many others, is now being studied in depth and the sampling of liquid process streams directly is now feasible. Examples from each of the above development areas are presented together with suggestions for further work.

On-line measurement of total sodium in liquid process streams by neutron activation analysis

A method based on the principles of neutron activation analysis has been developed to measure total sodium in liquid process streams. This method uses the /sup 23/Na(n,p)/sup 23/Ne reaction to produce an activation product which can be removed from matrix interferences by a gas purge followed by ..beta.. counting of the purged gas. Fluorine, thorium, and uranium are the only known interferences. The method is applicable for sodium concentrations greater than 0.1%. The electronics have been proven in on-line applications.

Analytical Control of Liquid Process Streams is Here!

Analytical Control of Liquid Process Streams is Here!

Analytical Control of Liquid Process Streams is Here!

Analytical Control of Liquid Process Streams is Here!

Radiochemical analysis of radium, thorium and protactinium in uranium milling process samples

226Ra, 230Th and 231Pa in solid and liquid process streams from a uranium mill have been analysed. The concentrations of the elements in the range from 10 −6 to 10 −2 ppm have been determined with an accuracy of about ±10 per cent.

Monitor cell for alpha activity in liquid process streams

An in-line monitor cell for alpha activity that has good resistance to contamination is described.