Waste-activated sludge, effect

Soft solids, most of which are biological waste such as sewage, are difficult to convey up the beach. Annular baffles or dams have been commonly used to provide a pool-level difference wherein the pool is deeper upstream of the baffle toward the clarifier and lower downstream of the baffle toward the beach. The pool-level difference across the baffle, together with the differential speed, provide the driving force to convey the compressible sludge up the beach. This has been used effectively in thickening of waste-activated sludge and in some cases of fine clay with dilatant characteristics. 

Hickey, R.F., Vanderwilen, J., and Switzenbaum, M.S., The effects of organic toxicants on methane production and hydrogen gas levels during the anaerobic digestion of the waste activated sludge, Water Res., 21, 1417-1427, 1987. 

The effect of branching on the performance of 75% DADMAC/25% acrylamide copolymers in dewatering 100% waste-activated sludge was also investigated. A series of copolymers was prepared by an inverse emulsion method adding up to 0.5 mol % TAMAC (based on DADMAC... 

Table I. Effect of MBA Addition to D ADM AC Emulsion Polymers for Dewatering 100% Waste-Activated Sludge...

Therefore, we can state that branching enhances polymer efficiency in dewatering activated sludges. An optimum degree of branching produces the best dewaterability. This effect is specific to waste-activated sludges. 

Kim J, Park C, Kim TH, Lee M, Kim S, Kim SW, Lee J. (2003). Effects of various pretreatments for enhanced anaerobic digestion with waste activated sludge. JBiosci Bioeng, 95, 271-275. 

Eskicioglu C, Teizian N, Kennedy KJ, Droste RL, Hamoda M (2007) A thermal microwave effects for enhancing digestibility of waste activated sludge. Water Res 41 2457-2466... 

Waste activated sludge was an effective source of PHB-accumulating micro-... 

ATP measured by luciferin-luciferase BL assay was used to examine the effect of toxic substances on whole microbial communities in activated sludge mixed liquid samples [114], It was used to detect whether wastewater had an effect on the biodegradation capability of the resident population of microorganisms. Actually ATP BL represents an important rapid toxicity test that utilizes waste treatment natural microorganisms to determine the toxicity of wastes discharged to the sewer [132],... 

But the most-used toxicity tests are based on bioluminescence inhibition, the responses of which are sometimes difficult to interpret particularly for waste-water quality monitoring. A comparison between a bioluminescence test kit (Microtox) and a respirometry approach for the toxicity study of seven organic and five inorganic toxic compounds was performed [54]. The bioluminescent response proved to have a higher sensitivity to toxicants but was less representative of the effects on activated sludge compared to respirometry, due to the nature of the microorganisms involved in each procedure. 

N. A. Leipzig, Effectiveness of the powdered achvated carbon activated sludge system in removing ammonia from an organic chemical produchon wastewater. Proceedings of the 35th Industrial Waste Conference, Purdue University, Lafayette, IN, pp. 889-897, 1980. 

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