Sixth framework programme

1.11Work package descriptions

1.11.1WP1 Project scoping:

Objectives

The aims of this Work Package are:

1. 
   to ascertain the overall costs associated with individual modes of operation of the three main commercial membrane bioreactor technologies which have been studied at pilot scale by several of the partners,
   
2. 
   to provide information on overall costs, and well as parameter values for appropriate base operating conditions, to be employed throughout the subsequent experimental programme,
   
3. 
   to extend the analysis to encompass literature data and data arising from other WPs
   

Methodology / work description

The initial analysis will take place in 5 stages:

1. 
   Acquisition of data (WP1.1a),
   
2. 
   Collation of data (WP1.1b),
   
3. 
   Calculation of normalised parameters (WP1.2a),
   
4. 
   Cost model development, benefit and optimisation based on normalised data (WP1.2b), and thus
   
5. 
   Identification/validation of base operating conditions.
   

The analysis will subsequently be extended as further data arises from individual WPs from the study (ref. graphic presentation of WPs), such that the overall sub-programme comprises:

WP1.1 Data acquisition and collation from all partners

WP1.2 Calculation of normalised parameters and outline cost benefit using data from WP 1.1 & 1.2

WP1.3 Literature survey and cost analysis

WP1.4 Cost model development and refinement

WP1.5 Report, cost evaluation
Key to the analysis is the acquisition of data required for the calculation of generic normalised parameter values (Table 7). According to this simple analysis: the bulk of the energy demand is made up by aeration, where it is assumed to be directly proportional to the aeration rate and aerator depth. Impacts on permeability are ultimately manifested on costs associated with downtime, loss of product water from backwashing and membrane replacement. Impacts on flux are manifested in membrane capital costs.
Deliverables & Milestones

Month 3 Data acquisition and collation completed for all partners.

Month 6 Outline cost analysis, pilot plant data: identification of base operating conditions.

Month 12 Cost analysis, literature data (incl. pilot plant trials conducted by partners).

Month 33 Cost analysis, all data

Month 36 Report: Cost model and cost benefit analysis, all data.

Rationale, innovation and contribution to knowledge

The dichotomy over the respective benefits of analogue and real matrices for research and development purposes is ubiquitous. The use of analogues for feedwaters in water and wastewater treatment R&D allows total control of feedwater quality. On the other hand it is universally recognised that analogues can never satisfactorily represent real sewage, particularly so in the case of crucially important parameters such as fouling propensity.

Recent years have seen a significant increase in the number of pilot plant studies based on real sewage feedwaters, and these include comparative studies by four of the partners. A vast number studies, mainly at bench scale, have been conducted in which hydraulic performance (i.e. permeability and/or its rate of decline) has been correlated with specific operating parameters and other system characteristics such as aeration rate or hydrodynamic parameters derived from aeration, biomass concentration or biomass-derived candidate foulant concentration and membrane characteristics. However, correlations produced from data derived from different pilot and/or full-scale studies have been rare and, in particular, the bases for cost evaluation, in those instances where such data is produced, are not always clear and rarely the same between different studies.
In this WP the cost issue will be addressed through identifying and calculating key unifying normalised parameters (Table 8) across a number of studies within a single cost model. The work will initially focus the pilot trials conducted by the partners, before being extended to other literature data from pilot-scale operation. This will provide a valuable contribution to knowledge of MBRs in crystallising information from a large number of disparate sources and producing correlations of the normalised parameters ostensibly on a common basis. The WP will provide the backbone for the programme as a whole, allowing data arising from all other WPs to be processed and correlated on a common basis, and thereby permitting a proper evaluation of the influence of key operating parameters as well as non-operational parameters such as system size and feedwater characteristics and dynamic effects.
Table 8 Elements of cost model: examples of key operating and appropriate normalised parameters

Raw data		Normalised or derived data
Energy related data
Mean flux, l m^-2 hr^-1	J	Temperature-corrected flux, l m^-2 hr^-1	J’
Mean transmembrane pressure, bar	P	Temperature-corrected permeability, l m^-2 hr^-1 bar^-1	J’/ P
Fouling rate^A, bar/hr	(P1- P2)/ Δt	Corrected permeability decline^A	J’(1/P1- 1/P2)/Δt
Aeration rate, l hr^-1	Qa	Temperature, pressure-corrected aeration rate per unit membrane area, l m^-2 hr^-1	Q’a
TMP recovery, bar	ΔP	Permeability recovery	J’/ΔP
Backflush interval, min	tb	Total downtime per cleaning cycle, ttot	N(tb+τb)+τc
Backflush duration, min	τb	Loss of production per cleaning cycle per unit membrane area, L, l m^-2	NJ’bτb/60
Backflush flux, l m^-2 hr^-1	Jb	Production per cleaning cycle, R, l m^-2	J’tc – L – J’ttot
Number of backflushes per clean	N	Net flux, J’net, l m^-2 hr^-1	R/(tc+τc)
Cleaning interval, hr	tc	Dimensionless flow number, Qn	J’net/Q’a
Cleaning duration, hr	τc
Aerator depth, bar	Δpa	Energy demand number^B, En, bar^-2	Qn/(ΔP.Δpa)
Recirculation power consumption, W	prQr	Specific recirculation energy demand per unit membrane area, Er, W m^-3 m^-2	prQr/J’net
Other costs
Cleaning reagent strength, kg m^-3	C	Total mass reagent per clean, m, kg	Cv
Cleaning reagent volume, m^-3	v	Normalised reagent mass	m/R
Purification performance
Mean chemical oxygen demand, kg m^-3	COD	Removal of X, kg m^-3	ΔX
Mean biochemical oxygen demand, kg m^-3	BOD	% Removal of X	%ΔX
Mean total organic nitrogen, kg m^-3	TON	Biodegradability parameter	BOD/COD
Mean total suspended solids, kg m^-3	TSS	Organic carbon loading rate^C per unit membrane area, kg m hr^-1	ΔCOD/J’net

^AApplies to both permanent (irreversible) and temporary (reversible) fouling during cleaning and backflush cycle respectively

^BThe energy demand number assumes that the pressure drop across the ports of the coarse bubble aerator does not differ greatly between the technologies, such that he bulk of the pressure drop is associated with its positioning (i.e. depth) in the tank

^CBioreactor rather than membrane loading

All energy parameters are converted to electrical energy demand through conventional calibrations to determine pumping power efficiency

Work package nr.	WP1		Start date or starting event:				0
Activity Type	RTD/Innovation activities
Participant id	CU	UNITN		Polymem	EV
Person-months per participant:	9	2		5	2

Objectives - to ascertain the overall costs associated with individual modes of operation of the three main commercial membrane bioreactor technologies which have studied at pilot scale by several of the partners, - to provide information on overall costs, and well as parameter values for appropriate base operating conditions, to be employed throughout the subsequent experimental programme, - to extend the analysis to encompass literature data and data arising from other WPs

Description of work This work package has been divided into sub-tasks. The nature of this activity requires high a degree of collaboration and interaction between the respective partners. The following gives a brief description of the proposed tasks; 1.1 Data acquisition and collation from all partners, In recent years a vast number of studies have been conducted on a bench scale and pilot plant scale levels for various MBR configurations (i.e. mode of operation, module design, type of membrane, analogue/real wastewater etc.) Collection and collation of this data from the project partners will first be conducted. 1.2 Calculation of normalised parameters and outline cost benefit using data from WP 1.1 & 1.2, Analysis derived from this data and presented in reports and publications is not always directly comparable. Key to the applicability and analysis the data acquisition of data is the calculation of generic normalised parameter values. A basis for normalized data will be developed. This will provide a valuable contribution to knowledge of MBRs in crystallising information from a large number of disparate sources and producing correlations of the normalised parameters ostensibly on a common basis. 1.3 Literature survey and cost analysis The work will initially focus the pilot trials conducted by the partners, before being extended to other literature data from bench and pilot-scale operations. 1.4 Cost model development and refinement, In this WP the cost issue will be addressed through identifying and calculating key unifying normalised parameters (Table 1) across a number of studies within a single cost model. The cost model will be refined and supplemented with data from the other WPs conducted in the project. 1.5 Report, cost evaluation, The WP will provide the backbone for the programme as a whole, allowing data arising from all other WPs to be processed and correlated on a common basis and presented in reports and a proposed cost model.

Deliverables D1 – Data acquisition and collation completed for all partners D9 – Outline cost analysis, pilot plant data: identification of base operating conditions D16 – Cost analysis, literature data (incl. pilot plant trials conducted by partners) D33 – Outline cost analysis, all data D40 – Report: Cost model and cost benefit analysis, all data

Milestones and expected result M1.1 +3: data acquisition completed M1.2 +6: identification of optimum/base operating conditions M1.3 +12: cost analysis, literature data M1.4 +36: final report: Cost model and cost benefit analysis, all data