Sludge absorption

Pre-liming. Lime slurry, 0.25% lime on juice (0.250 g of CaO/100 g juice), is added to bring the pH of the mixture into the alkaline range. Insoluble calcium salts are precipitated as finely dispersed coUoids. Calcium carbonate in the form of recycled first carbonation sludge is added to provide coUoid absorption and stabilization. Temperature may be cool (50°C) or hot (80°C) depending on the temperature of the next step, or occasionally on the type of diffusion equipment. Retention time is 15 to 30 min. 

The uv—hydrogen peroxide system has advantages over the iron—hydrogen peroxide (Fenton s reagent) procedures, eg, the reaction is not limited to an acid pH range and the iron catalyst and resulting sludges are eliminated. However, the system to date is not effective for dye wastewaters because of absorption of uv by colored effluent. 

Septic Tank Untreated liquid household wastes (sewage) will quickly clog your absorption field if not properly treated. The septic tank is a holding tank in which this treatment can take place. When sewage enters the septic tank, the heavy solids settle to the bottom of the tank the lighter solids, fats and greases partially decompose and rise to the surface and form a layer of scum. The solids that have settled to the bottom are attacked by bacteria and form sludge. 

In wet FGD systems, fine gas exiting from the particulate collector flows to an absorber. In the absorber, the flue gas comes into contact with the sorbent slurry. The innovative scrubbers in the CCT program featured a variety of technologies to maximize SO, absorption and to minimize the waste disposal problems (sludge). 

Where only silica is present, it can be removed by absorption into added ferric or magnesium hydroxide. The resulting sludge is removed by BD. 

Water and sludge Acidify sample measure absorption at 196.0 nm using the selenium atomic line. AAS 0.25 NR Parvinen and Lajunen 1994... 

A molecular absorption spectrophotometry method, using a sharp-line irradiation source, has been developed for the determination of sulfide (as hydrogen sulfide) in water and sludge samples. The method was tested with measurements of real waste-water samples. The limit of detection was 0.25 g (1-10 mL sample volume). 

Hitz HR, Huber W, Reed RH (1978) The absorption of dyes on activated sludge. J Soc Dyers Colorists 94 71-76... 

Smirnova et al. [5] have described a simple non-enzymatic method of quantitative determination of adenosine triphosphate in activated sludge from aeration tanks. Extraction of the nucleotides in boiling distilled water was followed by removal of the protein impurities by acidification. Barium salts of di- and triphosphates of the nucleotides were precipitated and the precipitate was washed and dissolved in acid to convert the barium salts to sodium salts. The quantity of adenosine triphosphate was determined quantitatively by inorganic phosphorus in the liquid over the precipitate before and after acid hydrolysis, and by ultraviolet absorption spectra. The method was tested in activated sludge from operational sewage works. There was good agreement between the adenosine triphosphate content determined spectrophotometrically and by phosphorus, despite the presence of small quantities of secondary impurities. 

HasweU and Barclay [3] have described a microwave system coupled to an atomic absorption detection system for the analysis of sludges and soils. A major constraint at the present time is that the preferred operation of these types of systems is for sample matrices to be closely matched. A widely varying sample, which exhibits different heating characteristics, wiU either show up as an invaHd result or the time required to cope with this procedure for aU the samples wiU greatly extend the on-Hne analyses time scales. As more of these instrumental systems become Hnked to laboratory information management systems, it wiU become feasible to interact between the control database and the instrumentation so that each sample is treated in an appropriate manner and the optimum time frame is selected for each sample type. When new samples are analysed, the steps could be monitored so that the required time scales are obtained and then stored for future reference. 

Table 1 can be used as a guide to define hazardous wastes from textile plants. Besides the direct toxicity of substances like chlorinated hydrocarbons, organo-Hg compounds, or concentrated alkaline solutions, other parameters have been defined with regard to problems during biodegradation or accumulation in the sludge from CWWT. A particular situation is found with colored effluents, where limits for spectral absorption have been defined. While the toxicity of textile dyes is comparably low, these limits were derived from the visual aspect of the water released from a textile plant because they look unhealthy. ... 

Cross-media pollutant transfer through volatilization of compounds and absorption of chlorinated organics to wastewater particulates and sludge. 

Fortescue,). A. C., Silvester, M. D., Abercrombie, F. N., The Chemical Composition of Sludge from Six Sewage Plants in the Niagra Penninsula, Ontario, Canada as Determined by Atomic Absorption and Emission Spectroscopy Using an Inductively Coupled Plasma Source , Proceedings of the 9th Annual Conference on Trace Substances in Environmental Health, Columbia, Missouri, June, (1975). 

Firstly, the concentrations of HMs in effluent were determined. At least three samples of 40 mL were acidified with 10 mL of concentrated HNO3 to decompose MOs. These samples were diluted to the sensitivity range of the atomic absorption spectrophotometer (AAS) (Model Philips 9200X-AAS) (diluted 5 times for Cu2+ analysis, and 25 times for Zn2+ analysis) and then analyzed. The average of these measurements yielded the total HM concentration in the effluent, / j (mg/L), for that specific experimental run. To convert (mg metal/L) to (mg metal/kg sludge), the measured metal concentration (as, mg metal/L) at each HRT was divided by the steady state MLSS concentration (as, kg TSS/L). 

Chau, Y.K., Zhang, S. and Maguire, R.J. (1992) Determination of butyltin species in sewage and sludge by gas chromatography-atomic absorption spectrometry. Analyst, 117, 1161-1164. 

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