Wastewater sludge dewatering with the use of «Sibfloc^®» flocculant and special wells

Summary

The technology of high-efficient wastewater sludge dewatering on sludge beds with the use of brand new «Sibfloc^®» flocculant made on the basis of polyethylene oxide and special slotted wells for the collection and removal of sludge water is described. The technology has been tested under various climatic conditions – from the Krasnoyarsk Area to the Krasnodar Area and introduced at the wastewater treatment facilities in Russia and Kazakhstan. The suggested technology when used on sludge beds provides for wastewater sludge dewatering to 68–75% moisture content; under the effect of «Sibfloc^®» flocculant the sludge is structurized and readily dried to 40–45% moisture content after unloading from the sludge bed. The sludge generated during dewatering is suitable for any type of utilization – from direct use as soil conditioner for reclamation of dumps and solid waste landfills to processing into fertilizers and soil for forest plantation. Sludge not suitable for any utilization because of fast drying capability to any moisture content (from 60 to 8%) can be efficiently used in biogas generating plants or special furnaces either in its initial state or in the form of fuel bricks. Technical and economic performance and environmental effect of using the considered technology allow classifying it as a best available technology. Introducing the technology of wastewater sludge dewatering with the use of «Sibfloc^®» flocculant provides for 4–7 times reduction of the required number of sludge beds, and improvement of sanitary and environmental situation at the treatment facilities and adjacent territories, including efficient odor control and unloading filled up sludge beds and sludge tanks.

Key words

dehydration , flocculant , wastewater sludges , treatment facilities , sludge bed , slotted well , reclamation

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УДК

Stern A. D.

Criteria for choosing a supplier of pumping equipment

Summary

В последнее время, особенно после различных семинаров и конференций, общения специалистов с руководителями и техническим персоналом предприятий водоснабжения и водоотведения, можно услышать, что все уже устали от общей рекламной информации по насосному оборудованию. Все это представители водоканалов много раз слышали и видели. Появление усовершенствованных образцов, несомненно, влияет на потребительские свойства насосного оборудования, но в свете существующих у водоканалов проблем эти преимущества отходят на второй план.

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UDC 628.311

Choosing the method of gravity flow measurement in public sewers

Summary

The aspects of choosing the method of measuring the flow rate and volume of wastewater gravity flow, particularly in case when the measurement results are used in accounting procedures (commercial accounting) are considered. It is shown that before studying the methods of measurement possible replacing gravity flow with pressure flow shall be considered because pressure flow rate can be measured more accurately. This measurement option is optimal from the technical point of view; however, in case the pressure section in the gravity pipeline is not available additional expenses are required for the water main reconstruction. In case this option is unacceptable the following methods of gravity flow measurement shall be considered (in the order of application priority): «level-flow rate» with the use of standard orifices (weirs and flumes) according to MI 2406-97 regulatory document; «level-flow rate» without any orifices with preliminary calibration of the measuring section according to MI 2220-13; «velocity-surface area» with the use of ultrasound flow meters; studying the velocity profile of the cross-section of the water main; calculation-instrumental (balance). By the specific example of an ultrasound flow meter it is shown that the flow rate error subscribed by the technical documentation can be several times lower than the actual one.

Key words

flow rate , measurement error , wastewater , ultrasonic flowmeter , gravity flow , flow measuring flume , calibration of measuring section

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UDC