Methods for estimating quantities and qualities (Q&Q) of faecal sludge: field evaluation in Sircilla, India

Estimates of accumulated quantities and qualities (Q&Q) of faecal sludge are essential for developing city-wide management plans. However, standardized approaches are lacking, and examples in scientific literature make use of diverse methodologies and parameters, making their comparability and transferability difficult. This study field-tested an approach for estimating Q&Q in Sircilla, India, and compared three methods for measuring accumulated sludge: (1) faecal sludge accumulation rate from in situ measurement with a core sampler; (2) faecal sludge accumulation rate with volume emptied by desludging truck; and (3) sludge blanket accumulation rate with a core sampler. Measurements were taken at households and commercial establishments, samples were analysed for characteristics, and demographic, environmental, and technical data were collected with a questionnaire. The median TS, VS, and COD concentrations for all containments were 26.8, 17.8, and 32.0 g/L, respectively. The median faecal sludge accumulation rate estimated with the core sampler and truck were 53 and 96 L/cap·year, respectively. The median sludge blanket accumulation rate was 17 L/cap·year. Continued data collection in this fashion will lead to a better understanding of what is accumulating in onsite containments at regional levels.

Recycling of Electroplating Wastes without Formation of Galvanic Sludges

The reasons and eco-economic consequences of galvanic sludge accumulation in environment have been considered. The economic futility of recycling of galvanic sludges has been shown. It has been established that recycling of chrome-containing wastes together with waste pickle liquors of steel-rolling mills enables to fully regenerate all components of the above wastes without sludge formation. The chemical processes for regenerative recycling of spent alkaline copper solutions of all kinds have been described. Deacidification of some acid electroplating wastes permits to extract oxides of nonferrous and heavy metals. Employment of the developed technologies in common will allow recycling all kinds of electroplating wastes and electrolytes without formation of sludges. Such a complex approach has some undisputable ecologic and economic advantages.

The performance of sludge blanket clarifier against conventional settler under high water turbidity conditions

The performance of a sludge blanket clarifier was evaluated and compared to conventional settlers under high levels of turbidity and algae in the field and experimentally. Field data of sludge blanket and conventional clarifier operation were observed simultaneously for the treatment of highly turbid water. In addition, a comparison was carried out on turbidity removal efficiency, algae removal, and sludge accumulation pattern. Finally, these systems were simulated in the laboratory and operated to treat turbid water with high levels of turbidity and algae up to 80 NTU and 109cells/l respectively. Field data confirmed that the sludge blanket clarifier equipped with upper sludge cones has a high removal efficiency of turbidity and algae, ease of use and has insignificant sludge accumulation compared to the conventional settler. Further, laboratory experiments have confirmed that sludge blanket clarifier is also very effective for the treatment of high algae concentrations up to 109cells/l, with a short retention time, compared to a conventional settler, which was not effective under these conditions.