Diatomaceous Earth Filtration Research Articles

Application of Ozone with Physical Wastewater Treatments to Recondition Poultry Process Waters

Several wastewater treatments, including direct ozonation and a combination of ozonation with either slow sand filtration, dissolved air flotation, or diatomaceous earth (DE) filtration, were tested for their ability to recondition broiler process waters. The quality of broiler prechiller overflow water was significantly improved with all wastewater treatments examined, surpassing the USDA’s recycling requirements in nearly all trials. A combination of screening, DE filtration, and ozonation yielded the highest quality water. With this treatment, significant reductions in chemical oxygen demand, total solids, and the total microbial load including coliform bacteria and salmonellae of 87, 65, and 99.9%, respectively, were detected in the reconditioned prechiller water. Percentage of light transmission at 500 nm (%T) of treated water increased to 97% of tap water and compared favorably with %T of potable water. This same water treatment was tested on final carcass rinse and neck chiller overflow waters. The quality of these treated waters was also significantly improved. It was concluded that poultry process waters could be effectively reconditioned for recycling by screening, DE filtration, and ozonation. Furthermore, wastewater organic loads discharged to wastewater treatment facilities can be effectively reduced through these reconditioning practices.

Water quality and waterborne protozoa

The nature of waterborne outbreaks has changed during the past 100 years (3, 4, 8, 9, 27, 28). This changing scenario of epidemiology and etiology has included: i) a decrease in individual cases and average number of cases per outbreak; ii) an increase in the number of total outbreaks and of those in smaller community water systems; iii) a change of etiology (Figure 2); and iv) a change in the effectiveness of predicting outbreaks by conventional testing methods. Current problems regarding waterborne outbreaks include the inadequacy of current EPA guidelines, the failure of coliform levels to adequately predict waterborne outbreaks, the need for coagulation, filtration, and disinfection to remove Giardia and Cryptosporidium cysts, and the improper design and poor quality of operation of some water treatment facilities (9). The EPA proposals to deal with these problems include providing new criteria for the filtration and disinfection of all surface waters, revising coliform level regulations, and stressing the necessity of the use of multiple barrier systems (10). Importantly, no properly operated water treatment plant using conventional (multiple barrier) treatment with some form of filtration (direct filtration, slow sand filtration or diatomaceous earth filtration) with disinfection has been implicated in a waterborne outbreak of giardiasis or cryptosporidiosis (3). To better understand the role of Giardia and Cryptosporidium in waterborne outbreaks, we must study several technological and epidemiological questions including: i) what is the prevalence of these parasites in surface waters; ii) when recovered, are the cysts viable; iii) what species is recovered and is it transmissible to humans; iv) what role do wild and domestic animals play in contaminating surface waters; and v) what alternatives exist for removal or inactivation of protozoan cysts. Procedures for recovering protozoan cysts from the environment are insensitive, expensive, and tedious (7, 22). Improvements in such techniques are essential for better delieation of the aforementioned questions. While protozoans may play a significant role in waterborne outbreaks, these cases may account for a relatively small proportion of the total Giardia and Cryptosporidium cases in the United States. These waterborne outbreaks, however, undoubtedly fuel the endemic and occasional epidemic nature of these infections in the general population, especially in day-care centers. A better understanding of the environmental dynamics of these protozoan parasites will enable us to limit the spread and disease caused by these agents.

Rapid isolation of Tamm-Horsfall glycoprotein (uromodulin) from human urine

An isolation method for Tamm-Horsfall protein is described which is based on the observation that a diatomaceous earth filter is able to retain most of the glycoprotein present in urine and that the glycoprotein is easily desorbed from the filter by deionized water. This behaviour depends on the tendency of Tamm-Horsfall glycoprotein at normal urinary concentrations to form a gel in a solution containing mono- and divalent ions. By means of two-step filtration, the glycoprotein was purified to homogeneity. The yield was of about 20 mg/l of urine, and the time required for the isolation was approximately 5–6 h. This procedure should be particularly useful for preparing large amounts of Tamm-Horsfall glycoprotein oligosaccharides in order to investigate their potential use as immunosuppressive agents both in vitro and in vivo.

Effect of Chilling Broiler Carcasses with Reconditioned Poultry Prechiller Water

Broiler prechiller overflow water was reconditioned using diatomaceous earth (DE) filtration and ozonation (30.4 mg/L ozone). Reconditioned chiller water meeting the United States Department of Agriculture recycling criteria was used in chilling broiler carcasses. The carcasses were compared chilled with fresh water and crushed ice or with reconditioned chiller water and ice. No significant treatment differences between measures of carcass quality including skin color, taste, or shelf life were detected. Furthermore, no significant differences between whole carcass rinse aerobic plate counts, or coliform and Salmonellae counts were found for carcasses chilled with fresh or reconditioned chiller water. In conclusion, poultry processing waters may be conserved through recycling practices without adversely affecting the wholesomeness of the carcass.

Research Note: Reconditioning of Prechiller Overflow Water Using a Diatomaceous Earth Pressure Leaf Filter

Broiler prechiller water from a commercial broiler processing plant was successfully reconditioned using a bench top diatomaceous earth (DE) pressure leaf filter. The volumes of DE precoat and body feed used in this study were .15% and .075%, respectively, of the chiller water volume. Flow rate was held constant at 84 mL/min. The DE filtration resulted in significant reductions in chemical oxygen demand (70.9%) and aerobic plate counts (90 to 96%). Water clarity or percentage of light transmission (%T, 500 nm) of the filtered water improved significantly to an average %T value of 97.9%.

Injectivity Improvement of Xanthan Gums by Enzymes: Process Design and Performance Evaluation

Summary. Injectability and filterability of xanthan gum dispersions, especially in hard brines, can be considerably improved by successive use of cellulose and alkaline protease enzyme treatments. A thorough optimization of the different parameters controlling enzymatic activity has led to an original clarification process. Improvements observed in flow behavior of treated xanthan gum solutions through reservoir rocks is the result of almost complete elimination of both insoluble bacterial cells and microgels. Introduction Aqueous xanthan gum dispersions prepared either by dilution of raw fermentation broths or by dissolution of xanthan powders still contain insoluble particles and microgels. Different treatments, including, diatomaceous earth filtration or the action of protease enzynes, have been proposed to improve the limpidity and thereby the injectability of diluted xanthan gum solutions. These clarification procedures were shown to be unable to reduce the plugging, capacity of shear-deformable microgets at a very short distance from the injection well. The result is a poor sweeping efficiency of reservoir rocks by imperfectly clarified polysaccharide solutions. Plugging by microgels can be reduced by subjecting xanthan gum dispersions to the action of polysaccharase enzymes. This treatment is considered satisfactory it applied to xanthan powder dispersions containing, a limited amount of residual dead bacterial cells. The higher biomass content of raw xanthan broths renders the cellulose treatment less efficient. A synergetic effect in elimination of both microgels and insoluble particles is obtained by application of polysaccharase and protease treatments either successively or simultaneously. This paper describes the process resulting, from previous studies and enables these treatments to be performed previous studies and enables these treatments to be performed either in the field or at the factory site at the end of the biopolymer fermentation process. Performance evaluation of the enzymatic treatments on xanthan broths and Powders, respectively, was carried out by injection of the resultant solutions at high and low flow rates through both calibrated filters and natural cores. Fundamentals of Enzymatic Treatments Recent publications have shown that it is easy to hydrolyze the main chain of the xanthan molecule by polysaccharase enzymes, commonly called celluloses. As a polysaccharase enzymes, commonly called celluloses. As a consequence, glucose or reducing sugars are released in solution, and both molecular weight and viscosity diminish. Nevertheless. hydrolysis through cellulases occurs only if the xanthan molecule is in an unordered conformation. This conformation prevails at room temperature in low-salinity brines and at higher temperatures if salinity is high. Similar treatments applied to raw xanthan gum dispersions in brines with an overall salinity greater than 5 × 10 mol/L and at temperatures lower than 65 degrees C [149 degrees F] were shown to contribute to the clarification of these solutions and to the progressive microgel elimination. With this treatment. the main xanthan chain remains unaltered, the viscosity of the polymer solution is unchanged, and the xanthan gum' s injectability is improved. Treatments by cellulases performed on xanthan gum dispersions in brines exhibiting greater hardness were nevertheless found to be unsatisfactory. A synergetic treatment was therefore developed consisting of two successive enzymatic treatments, one at pH 4.5 and 50 degrees C [122 degree F] with a cellulase and the second at pH 9 and 50 degrees C [122 degrees F] with an alkaline protease. This process allows almost total microgel elimination and improvement in the filterability of the resultant xanthan gum solutions. Experimental Polymers. The main characteristics of the xanthan gums Polymers. The main characteristics of the xanthan gums tested throughout this study are listed in Table 1. Both fermentation broths and powdered-form products of various origins were used. Enzymatic treatments were applied to xanthan gum dispersions with concentrations ranging from 1 to 9 wt%. For laboratory tests. no special equipment was used to disperse the polymer; gentle stirring in the hydrolysis unit for about 2 hours before enzymes were added was found to be sufficient. For pilot tests (1 m [264 gal]), a special dispersion device was pilot tests (1 m [264 gal]), a special dispersion device was used for the powder to ensure complete solubilization of the polymer in less than 2 hours. Enzymes. Two types of enzymatic preparations that are commercially available in powder form were used throughout this study: JPT P. 835

Process development for manufacturing of diatomaceous earth filter aids

A pilot plant, capable of treating three tons of diatomaceous earth per day, has been operated to obtain optimum design criteria for scale-up to the commercial plant [1]. High quality filter aids, such as DICALITE [2] have been produced. A commercial plant has been completed in Kyongju city by scale up of this pilot plant test. Selective diatom-earth preparation, homogeneous calcination of diatom-cells-mixture, proper delumping and pneumatic concentration of diatom-cells are main process schemes [3]. The most efficient grinding effect has been obtained using a milling blower, as of two-cage disintegrator [4]. Variable-speed rotary kiln has been operated to convert the diatom-cells into more porous and pure products. Diatom-filter-aids, in the size range of 10-40 microns, are completely separated pneumatically by back wash cyclones.

New York City's Ozone Demonstration Plant Design

Designand construction specifications of a 3 mgd (12, 187 m3/day) demonstration plant to treat water by ozonation followed by diatomaceous earth (DE) filtration at New York City's Jerome Park Reservoir are described. The primary treatment objectives are to maintain a treated water quality of turbidity below 0.2 NTU, color below 3 color units, and iron and manganese below 0.3 mg/L. Three process trains will be employed, each operating at a maximum of 1 mgd (3,786 m3/day), to test variousmodificationsof theozone/DE process. The demonstration plant is scheduled to operate approximately one year, beginning in April 1986, to provide data for a full-scale plant to be constructed later in the decade.

Certification Corner

Questions presented cover the following topics: amount of calcium hypochlorite required for a given chlorine dosage; diatomaceous earth filter septum body coat; green algae pigments group; carbon dioxide and pH; venturi meters; and amount of surficial water on the earth.

Ultraviolet light control of Ichthyophthirius multifiliis Fouquet in a closed fish culture recirculation system

Abstract. A closed fish culture recirculation system consisting of 36 20‐gallon aquaria in series with a rotating plate biofilter, a diatomaceous earth filter, and an ultraviolet (UV) light sterilizer was evaluated for the effectiveness of UV light in preventing spread of Ichthyophthirius multifiliis. Water from the aquaria, the reservoir, and a valve 29 cm beyond the UV light source was analysed bacteriologically to assess its effectiveness. The spread of I multifiliis from one aquarium to another was controlled with 91 900 μW s/cm8 of UV light. No significant differences in the bacterial counts from the water of the reservoir or the aquaria could be demonstrated when the UV light was either on or off, although a significant difference could be demonstrated between the sterilizer effluent and the reservoir and aquaria.

Water dechlorination by activated carbon, ultraviolet radiation and sodium sulphite: A comparison of treatment systems suitable for fish culture

The characteristics of water dechlorination by activated carbon filtration, u.v. irradiation and sodium sulphite injection were examined. A pilot plant water treatment system composed of sand and diatomaceous earth filtration, ozonation and activated carbon filtration was evaluated. Activated carbon did not completely eliminate chlorine under any conditions tested but the post-carbon chlorine concentrations were relatively insensitive to large variations in incoming chlorine levels and water flow rates. Carbon filtration also reduced total dissolved organic carbon concentrations by 65% and reduced various halogenated methane derivatives by 97–100%. Ultraviolet irradiation eliminated up to 99% of the total chlorine in municipal water but u.v.-dechlorination was sensitive to flow rate with a rate constant of 2.02 min −1 between 10 and 27 l min −1. Water temperatures ranging from 7.5 to 20.6°C did not affect the efficiency of dechlorination by activated carbon or u.v. irradiation. Sodium sulphite at a 3:1 molar ratio to chlorine completely eliminated chlorine from municipal water while a sulphite:chlorine ratio of 6:1 was required to completely dechlorinate water which had been partially dechlorinated by activated carbon. The results are discussed in relation to the design of a multi-stage system suitable for providing dilution water for aquatic toxicity studies and fish culture.

Getting your money's worth from filtration

In the 1980s water filtration plant operators may need to remove particulate contaminants, such as asbestos or Giardia cysts, in addition to algae, bacteria, soil particles, viruses, and other particles that filters previously were intended to remove. Even though the contaminants of concern may change, the fundamentals for effective filtration that were stated in earlier years still are valid. Moreover, recently acquired data substantiate recommendations made in the 1960s for granular‐media filtration. In this paper techniques for effective operation of diatomaceous earth, rapid granular‐media, and slow sand filters are discussed. If filters are operated in a way that results in effective particle removal, the capital investment made to build the filters is returned in the form of high‐quality drinking water.

Pseudomonas aeruginosa skin infections in persons using a whirlpool in Vermont

Four guests at a ski resort in Vermont reported contracting a characteristic papular, pustular, or vesicular rash after using the resort's whirlpool. Pseudomonas aeruginosa serotype 1, bacteriophage type 86, was isolated from a pustule on one patient, water within the whirlpool, and the whirlpool diatomaceous earth filter. This appears to be the first outbreak of dermatitis associated with P. aeruginosa serotype 1. Previous reports of whirlpool-associated dermatitis outbreaks have identified serotype 9 and 11 isolates of P aeruginosa as the causative agents.

Potential of Poultry Processing Waters for Reuse

Processing water from 10 point sources was evaluated for potential clean-up and reuse. Criteria used to evaluate the potential of these waters for renovation by diatomaceous earth filtration were levels of suspended solids, dissolved matter, grease, chemical oxygen demand, and biochemical oxygen demand.Water from the gizzard splitter after screening and total effluent after air flotation had the lowest levels, whereas water from the neck chiller and neck flume had the highest levels of suspended solids, dissolved matter, and grease. Based on suspended solids only, all 10 water sources tested would be suitable for renovation by diatomaceous earth filtration. However, the high level of grease in many of the samples would shorten the filtration cycle to an impractical level. Developing a method for grease removal would be necessary for renovating some of these water sources by diatomaceous earth filtration.

Water Quality Aspects of North Sea Injection Water

Summary This paper discusses current water quality assessment methods and some of the parameters that can affect the suitability of North Sea water as an injection fluid. Also included are general comments on the North Sea and its biomass. Examples are drawn from tests carried out during the commissioning of the Forties field seawater injection system in 1976-78. Introduction The use of seawater for subsurface injection is well known in many oil production areas. An area of particular interest at the present time is the North Sea, where the number of offshore seawater injection facilities is increasing rapidly. The high expense of offshore operations plus the high capital cost of the platform very often impose severe constraints on the design engineers, particularly in terms of the size and weight of treatment facilities. An important factor affecting the success of a waterflood project is the quality of the water being injected. Generally, the design basis is such that the water quality should enable injection for the life of the project at a minimum injection pressure and minimum cost. However, very often the quality standards required for injecting a particular water into a particular formation are not known in the early stages of the project. Design Considerations The water quality requirements for successful injection of seawater into North Sea reservoirs is a highly controversial topic at the present time. Water quality is affected by several types of contaminants including suspended solids, scale, oil, bacteria, corrosion products, and marine organisms. Generally, the major water quality problems associated with a seawater flood are due to colloidal iron formation and the presence of organisms. In the past, such problems have been overcome by using other sand or diatomaceous earth filters or by hydraulic fracturing of the formation. However, some operators have experienced problems with the latter approach due to sand influx into the injectors and fracture breakthrough into the producing wells. In an offshore situation, sand or diatomaceous earth filters can be employed only at considerable cost due to their size and weight. In this respect it is essential, therefore, that water quality specifications and designs are adequate but not ultraconservative.North Sea water generally is good quality, containing between 0.2 to 0.8 mg/L suspended solids as determined by membrane filtration techniques. The Forties field seawater injection system has been described previously, and a schematic diagram of the system (capable of handling 150,000 B/D of water) is shown in Fig. 1. Because of the general good quality of water present in the Forties area and weight limitations on the platform, two back-washable cartridge filters are employed. A four-pod filter containing an 80-micron stainless steel element located downstream of the seawater winning pumps provides the first stage of filtration (coarse). A second stage of filtration (fine) is achieved using another filter skid, containing a fiber element, located immediately upstream of the main injection pumps.Initially, there were several problems associated with the fine filters, mainly concerning the backwash and filtration efficiency. To overcome those problems, a considerable development effort was carried out by BP Petroleum Development during 1976–1978. Although that study was aimed primarily at obtaining an efficient backwashable filter element, the data also were employed to investigate present water quality prediction methods. This is of considerable importance as there is very often the need to assess water quality in an unknown environment. JPT P. 1141^

Further Studies on Soluble Iron in Filter Aids

Studies are reported on the correlation of phthalate-soluble iron with beer-soluble iron for calcined and flux-calcined diatomaceous earth (D.E.) filter aids. Each type of filter aid was found to p...

Alternative filtration methods for removal of Giardia cysts and cyst models

The recent occurrence of waterborne giardiasis outbreaks has spurred renewed interest in water filtration for cyst removal. Studies with cyst models and Giardia muris cysts suggest that properly operated water filtration plants should be able to remove a high percentage of G. lamblia cysts. For effective cyst removal, diatomaceous earth (DE) filters need 1.0 kg/m2 diatomite precoat plus body feed, and granular media filters require coagulation of raw water and production of filtered turbidity well below 1.0 ntu throughout the entire filter run.

Large‐scale ozone‐DE filtration: an industry first

A comparative study of high‐rate conventional treatment, direct filtration with granular media, and ozone–diatomaceous earth (DE) filtration for treatment for an upland water supply in an urban area focused on water quality, efficiency of operation and maintenance, and esthetic and cost considerations. For this particular application, the ozone–DE treatment proved to be the process of choice.

The pretreatment of seawater RO feed using the UVOX (UV/oxidant) process

The UVOX process, which is essentially the retention of chlorinated (or conceivably ozonated) seawater for a period of about 3 days in open ponds, has been developed and proved to be effective in improving the treatability of nutrientrich recalcitrant seawater, to the extent that simple sand filtration and/or diatomaceous earth filtration will yield a feedwater, for RO desalination, with a plugging index of less than 45 per cent. The process eliminated the need for chemical coagulation and relatively expensive clarification systems.

Construction, operation and performance of a modified diatomaceous earth filter for shellfish hatcheries

A commercially available diatomaceous earth filter has been successfully modified for microfiltering sea water used to grow bivalve larvae. The filter consistently removes up to 96% of the suspended matter in the water down to at least 2.3 microns, and reduces the number of heterotrophic bacteria to between 1 and 5 × 10 2 ml −1. Growth and development of bivalve larvae in this water is excellent.