Characteristics of grey wastewater

Publisher Summary This chapter focuses on the polymeric reserve materials and thus excludes the consideration of lipids other than poly-β-hydroxybutyrate, and the disaccharide trehalose, which plays an important role in the economy of the yeast cell, but displays certain features that are at variance with the normally accepted behavior of storage compounds. The chapter considers the evidence for the energy-storage roles of glycogen, polyphosphates and poly-p-hydroxybutyrate, and the current state of knowledge concerning the regulation of their biosynthesis and degradation in the microbial cell. The intracellular location of the enzymes concerned with polymer synthesis and degradation is an intriguing problem. The most detailed work has been carried out with PHB granules, which have PHB synthetase and a factor involved in depolymerase activity associated with the membrane that bounds the granule. The depolymerase system is a complex one that also involves a soluble fraction, underlining the importance of reactions at liquid-solid interfaces in the process and emphasizing that relatively little work has been done to isolate polyphosphate or glycogen granules in their native state in order to examine the possibility of regulation by a membranous system.

The Role and Regulation of Energy Reserve Polymers in Micro-organisms

Bioflocculation in activated sludge: an analytic approach

Affordable and effective domestic wastewater treatment is a critical issue in public health and disease prevention around the world, particularly so in developing countries which often lack the financial and technical resources necessary for proper treatment facilities.

This practical guide provides state-of-the-art coverage of methods for domestic wastewater treatment and provides a foundation to the practical design of wastewater treatment and re-use systems. The emphasis is on low-cost, low-energy, low-maintenance, high-performance 'natural' systems that contribute to environmental sustainability by producing effluents that can be safely and profitably used in agriculture for crop irrigation and/or in aquaculture, for fish and aquatic vegetable pond fertilization. Modern design methodologies, with worked design examples, are described for waste stabilization ponds, wastewater storage and treatment reservoirs; constructed wetlands, upflow anaerobic sludge blanket reactors, biofilters, aerated lagoons and oxidation ditches. 

This book is essential reading for engineers, academics and upper-level and graduate students in engineering, wastewater management and public health, and others interested in sustainable and cost-effective technologies for reducing wastewater-related diseases and environmental damage.

Domestic Wastewater Treatment in Developing Countries

Retention and removal of pathogenic bacteria in wastewater percolating through porous media: a review.

The development of waste water‐induced soil clogging in subsurface wastewater infiltration systems is investigated in the field over a 70‐mo period. Domestic septic tank effluent (DSTE), graywater septic tank effluent (GSTE), and tapwater (TW) are intermittently applied at 1.3, 2.6, and 5.2 cm/day to replicate 0.9‐m diameter pilot‐scale wastewater infiltration systems installed in situ in a structured silty clay loam subsoil. Soil clogging development is negligible under all TW loadings and under GSTE loadings at 1.3 and 2.6 cm/day. Under GSTE loadings at 5.2 cm/day and under all DSTE loadings, severe soil clogging development leads to continuous ponding of the soil infiltrative surfaces. A logistic model fit to the experimental data confirms that soil clogging development is highly correlated with the cumulative mass density loadings of total biochemical oxygen demand and suspended solids (R2=0.95). Wastewater composition as well as hydraulic loading rate need to be considered in system design and manage...

Wastewater‐Induced Soil Clogging Development

In order to effectively study and improve methods of on-site treatment and disposal of wastewaters from individual homes, quantitative and qualitative characterization of household wastewater is necessary. To enhance the existing characterization data base, field studies were conducted at the University of Wisconsin as part of the Small Scale Waste Management Project. Water use was monitored at ll homes for a total of 434 days. Various individual household events were studied and their usage characteristics were determined, including frequency of use, flow per use, and flow per capita per day. Daily and weekly flow patterns were also developed. Wastewater quality characterization was accomplished for the various households events by sampling at four homes for a total of 35 days. For each event and the various quality parameters, the concentration and mass of pollutants per event occurrence, and the mass of pollutants per capita per day were determined.

Characteristics of Rural Household Wastewater.

Organisms isolated from activated sludge and identified as Zoogloea ramigera accumulated large amounts of sudanophilic granules as the cultures flocculated The granules were extracted by chloroform and precipitated with ether from acid-hydrolyzed cells Identification of the sudanophilic granules as poly-beta-hydroxybutyric acid (PHB) was confirmed by physical, chemical, and infrared spectral analyses The isolated polymer accounted for 120 to 505% of the dry weight of the cells The polymer was not synthesized when the culture was grown in a growth-limiting concentration of organic substrate; it did accumulate when the culture was grown in medium enriched with carbon and energy sources An increase in concentration of intracellular PHB was directly proportional to optical density and uptake of glucose Aside from intracellular storage of PHB as endogenous metabolite, the accumulation of PHB is noted as a possible mechanism of flocculation

Isolation, identification, and metabolic role of the sudanophilic granules of zoogloea ramigera.

\IMeasurement of Oxygen Transfer in Clean Water\N was developed to calculate the rate of oxygen transfer from diffused gas and mechanical oxygenation devices to water. The Standard is applicable to laboratory-scale oxygenation devices with small volumes of water as well as to full-scale systems with water volumes typical of those found in the activated sludge wastewater treatment process. It is intended that this standard be used by engineers in the preparation of specifications for compliance testing. This test method is based upon removal of dissolved oxygen (DO) from the water volume by sodium sulfite followed by reoxygenation to near the saturation level. The DO inventory of the water volume is monitored during the rearation period by measuring DO concentrations at several points, selected so that each point senses an equal tank volume. The method specifies a minimum number, distribution, and range of DO measurements at each point. This procedure is valid for a wide variety of mixing conditions. The primary result of this testing is expressed as the standard oxygen transfer rate. The Standard also describes how clean water tests can be applied to estimate oxygen transfer rate in process water. In addition, various components of power consumption are defined; methods for measurement of gas rate and power consumption by oxygenation devices are given; and the preparation of data analysis is discussed.

Measurement of Oxygen Transfer in Clean Water

The existence of an intraparticle diffusional resistance in the uptake of organic substrate by particles of zoogloeal floc is established by comparing the glucose and oxygen uptake rates for large floc particles with those exhibited by the same particles after blending. A zero order effectiveness factor model predicting the magnitude of this diffusional limitation in terms of the particle size distribution, particle shape, uptake rate, substrate concentration, and effective diffusivity of the substance within the particle is developed by considering a particle of biological floc to be analogous to a porous catalyst particle. Mean values for the effective diffusivity of glucose in the zoogloeal floc material ranged from about 7% to 9% of the corresponding values for glucose in water. Subjecting activated sludge floc particles to high turbulence in a laboratory blender caused a marked increase in the oxygen uptake rate. This phenomenon was apparently due to the solubilization of some sludge components.

William C. Boyle

Papers

Wastewater‐Induced Soil Clogging Development

Characteristics of Rural Household Wastewater.

Isolation, identification, and metabolic role of the sudanophilic granules of zoogloea ramigera.

Measurement of Oxygen Transfer in Clean Water

Mass Transfer Limitations in Substrate Removal