Germany - flocculants

Description

Supply of flocculation aids (powder/granulate) for digested sludge dewatering by means of centrifuges. Total quantity 270 t (approx. corresponding to a 3-year requirement) Delivery in partial batches a approx. 7 tonnes in big bags, delivery in bagged goods not possible. The city of Bonn operates sewage sludge digestion and sludge dewatering at the Salierweg sewage treatment plant. The pre-dewatered surplus and primary sludge from the Salierweg sewage treatment plant is transported together with the sludge from the Bad Godesberg and Beuel sewage treatment plants to the digesters. After digestion, the digested sludge (1.8-3 % dry residue) is dewatered to 23-28 % dry residue with a daily volume of ~ 600 m through the various centrifuges with the addition of flocculants. A total of 3 centrifuges (Farikat: Flottweg) can be used for digested sludge dewatering. A site visit is recommended. Additional information: The total annual costs are obtained by adding the values A+B+C+D (see below). These values can only be determined using test evaluation. For the purpose of preliminary tests for the selection of the test product, sludge samples may, if necessary, be collected from the Salierweg sewage treatment plant (contact person Mr Daniel Groß Tel. 0228/ 6835-124 or Mr Achim Höcherl Tel. 0228/ 6835-100) NOTE: Part of this two-stage participation competition is a series of tests prior to the submission of the bid (prior to March/April 2019) in which the economic efficiency of the product is measured against that of the competitors. In addition to the specific determination of consumption, tests are also carried out on dry matter, separation efficiency, shear stability and concentration of chemical oxygen demand in the centrate. The trials will take place without the participation of company representatives. Inductive flow measurements by the customer are used for the quantity measurement of the flocculant as well as the sludge quantities. If the consumption of flocculants exceeds 12 kg per tonne of sludge (based on the dry residue content), the suitability test must be regarded as failed. Eligibility to participate in the limited series of tests is subject to fulfilment of the complete information/documents listed below (III.1.1, III.1.2 and III.1.3) and their evaluation in accordance with VgV. The tender documents will only be sent to the applicants for submission of tenders after the trial evaluation has been completed. A) The special flocculant consumption based on the dry matter content of the digested sludge multiplied by the offer price and multiplied by the expected annual dry matter sludge quantity (approx. 7,250 t) decides on the award of the contract. In addition to these costs for the flocculant, the following is added: B) Sludge dewatering produces centrate (aqueous phase with impurities), from which COD tests are carried out. The COD components must be degraded in biology. The COD contamination load determined in the centrate is included in the total costs. Costs for centrate wastewater treatment, COD in the centrate at an average centrate accumulation of 220 000 m , for the wastewater treatment of the centrate 0,20 EUR/kg COD is used; C) cleaning costs for removal of dust depending on the degree of dusting (low pollution 40 EUR/t flocculant, medium 80 EUR/t, high 120 EUR/t, very high 160 EUR/t, extremely high leads to exclusion); (D) costs for defoamers (experience shows between 0 and 6000 EUR). The total annual costs are obtained by adding the values A+B+C+D. These values are determined with the help of the test evaluation and form the basis for the evaluation of the economic efficiency of the product.

Opportunity closing date

06 February 2019

Value of contract

to be confirmed