section 11 – technical specification itb 21-2017 english

Wastewater Treatment Project in the village of Novo Konjarevo, Municipality of Novo Selo

TECHNICAL SPECIFICATION annexed to the Baseline Wastewater Treatment Project in the village of Novo Konjarevo,

Municipality of Novo Selo

1. INTRODUCTION

The basic demand when projecting wastewater treatment plants is to enhance the energy

efficiency and the superior quality of decontaminated waste waters. The communal

wastewater treatment plants have to align with the quality demands which increasingly get

higher, especially if this relates to BPK5, as well as the levels of nitrogen and ammonia, which

are growing as the population grows.

Most importantly, the wastewater treatment plant is expected to meet the required

standards and have minimum impact on the environment.

2. LAYDOWN AREA – WWTP (MBBR1000)

This laydown area shall cover the area of the village of Novo Konjarevo in the municipality of

Novo Selo, which is located at some 5km distance from the municipality of Novo Selo. There

is a project ongoing in the village of Novo Konjarevo, for construction of faecal sewerage

network, which is separated from the atmospheric sewerage network. The faecal sewerage

network in this area is gravitational.

The number of inhabitants of this laydown area, for which the project documentation is

developed, reaches 1000 inhabitants. Construction of WWTP - MBBR1000 was envisaged in

this laydown area, where recipient is Strumica River, that is, the collector projected to be

constructed near to the river.

The raw waste water was envisaged to contain minimum fats and oils, because the facilities

producing highest amounts of fats and oils are obliged to place separators where formed.

3. WASTEWATER QUALITY

The wastewater characteristics presented in the upper Table are in accordance with data

collected from literature on wastewater decontamination. The values have been adopted on

water supply norm of Q0 = 150 l/z/d.

Source of wastewater: Sanitary wastewater from residential areas.

Basic wastewater characteristics:

• High level of suspended substances

• High level of organic substances

• High level of microbiological activities

• Content of fats and oils, max. 50 mg/l

Typical composition of sanitary-faecal wastewater is presented in the Table below:

Table: Characteristics of communal water – pursuing available literature

Baseline Wastewater Treatment Project in the village of Novo Konjarevo, Municipality of Novo Selo

4. QUALITY OF PURIFIED WATER

By constructing the separated waterway system for communal wastewaters and WWTP –

MBBR1000, the treatment plant shall be intended to treat communal waste waters, by not

burdening it with industrial waters and thus, the required quality of the effluent shall meet

the effluent standards, given in the EU Directive on Urban Waters (91/271/EEЗ, 98/15/EЗ),

for sensitive areas;

Table. Comparative parameters with the necessary treatment level

Parameter

Expected

concentration of

wastewater

Limit values of

emission

Required level

of purification

– RLP (%)

pH 7,0 6,5 – 9,0 /

Temperature / 30 /

Suspended substances 367 35 90.5%

Deposits / 0,3 /

HPK 800 125 84,3%

BPK5 400 25 93,8%

Total fats and oils 120 20 83,3%

Parameter

Concentration mg/l

Limits Typical

Physical

Dry substance – total 300 -1200 700

Easily deposited particles 100 – 400 220

Suspended particles – evaporating 70 – 300 150

Dissoluble particles – total 250 – 850 500

Dissoluble particles – evaporating 100 – 300 150

Chemical

BPK5 100 – 400 250

HPK 200 – 1000 500

TOC 100 – 400 250

Nitrogen

Total 15 – 90 40

Organic 5 – 40 25

Ammonia 10 – 50 25

Phosphorus

Total 5 – 20 12

Organic 1 – 5 2

Non-organic 5 – 15 10

pH 7 - 7,5 7,0

Calcium 30 – 50 40

Chlorides 30 – 85 50

Sulphates 20 – 60 40


Total chlorine 0 0,4 0%

Total nitrogen 70 10 85,7%

Ammonia nitrogen 40 10 75%

Total phosphorus 16 2 87,5%

NOTE: In the given legislation, the totals of nitrogen and ammonia nitrogen have to be equal.

Total nitrogen: organic N + NH4-N + NO3-N + NO2-N. That would imply that the

mineralisation of organic substances has been fully implemented (the TKN would be 0), and

non-organic nitrogen should be absent, which is impossible.

Nominal temperature of entry water: min. + 12°C, Annual average +17°C, max. +20°C.

Nominal temperature of outdoor air: min. – 10°C, max. +28°C. To achieve limit values,

separation is necessary of atmospheric and faecal sewerage and only faecal wastewater

should be poured into the plant.

The treatment plant is projected under the Book of Regulations on terms, manner and limit

values of the emission of wastewaters following their purification, the manner of their

calculation, given the special requirements for conservation of protected areas (Official

Gazette of RM, nr. 81/11).

5. QUANTITY OF WASTEWATER

For the given scope of work, the water quantity is a result of the assessment of equivalent

inhabitants that shall benefit from the treatment plant by the completion of exploitation

deadline. Average daily water consumption per equivalent inhabitant (EI) reaches 150

l/day/inh.

The number of inhabitants in this laydown area, added to the ratio of population growth for

a 30-year period, amounts 1000 inhabitants. For this laydown area, construction of WWTP –

MBBR1000 was envisaged, having Strumica River as recipient.

The quality of purified water is expected to meet physical-chemical standards for discharge

in the surface watercourse – Strumica River.

Based on the hydraulic calculations made, the hydraulic dimensioning of WWTP was

completed, pursuing the following entry parameters, the number of inhabitants and the

water supply norm, which are the basic entry parameters for dimensioning treatment plants.

Number of inhabitants WWTP = 1000 E.I. (equivalent inhabitants).

Discharge norm reaches Qo = 150 (l/day/inh.).

Hydraulic dimensioning of WWTP

��/�� = �.�� .��.��

= �, ��/�, Average hourly wastewater flow.


�� = 1.5 +2.5

�� / !�"

�� = 3.39, Coefficient of daily fluctuations.

�%�&/ !�" = �'( /!�" ∗ ��(+ /',-) = 5,90+/'

0!�" =1 � /!�" ∗ 86400

1000= 150(%3/ !�")

Discharge norm for daily consumption should cover equivalent inhabitant Qo=150 l/day. It is

necessary to mount container type of treatment plant 1000 EI, in capacity of 150 m3/day,

which shall follow the principle of MBBR technology.

6. TECHNICAL PARAMETERS OF WWTP – MBBR1000

The treatment plant is consisted of AB pumping station, AB reservoir to collect wastewaters

and MBBR reactor.

The pumping station is attached to the reservoir and is consisted of 2 (two) carrier pumps

with the following characteristics: Q=3.5/s, H=5.50m. Each pump has special compression

pipeline leading to the first chamber of the egalisation reservoir. The pump station should be

accompanied by a locker with a count control, options for manual and automatic operation.

The automatics should be connected with a level of depth plumb-line to control the

operation of the pumps.

A pump is placed in the reservoir to organise the dosage of raw wastewater that should

further flow onto the central treatment plant. The basin is with volume of 50m3

serving to

level up the inflow quantities, and it also serves as a depositor.

The central treatment plant is of container type and is placed above a concrete panel. The

wastewater treatment plant in the treatment capacity of 150 m3/day (1000 PE) is in

compacted package 11,9 x 2,2 m. The station has to use a two-level technology MBBR

(Moving Bed Bio Reactor) (high and medium-size compression), projected for optimum

organic compression for high performance and production speed of mill <75 kg/day. The

energy consumption of this station is below 0,95 kWh/m3 of treated water. Besides, the

station is FULLY MOUNTED ON ONE SINGLE MOVING STRUCTURE, which covers a screening

system, bio reactors, decentralised and control chamber. These characteristics shall enable

easier movement and displacement of the system, it considerably reduces the space to place

visual effect and the device transport may be carried out by using a container or a platform

track. The MBBR system is a flexible solution due to its stability during outflows and

variations of loading, with no significant changes in the installation. Actually, the reactors

may be filled from 30%-70% of the carriers’ volume, making the adjustment of volume of

carriers and the aeration sufficient to cope with such variations.


The produced wastewater should meet the required limits for drainage into the

watercourse, according to the organic, physical and microbiological parameters as set in the

DIRECTIVE 91/271/EEC, into effect in Macedonia (BOD <25 mg/l, COD<125 mg/l, TSS<60

mg/l), having in mind the bio-degradable urban wastewater or equivalently to (BOD 400

mg/l, COD 1000mg/l, TSS 400 mg/l) and guaranteed outcome of purification that is higher

than 90%.

The device has to be robust, fitting and modularly, manufactured as per CE certificate. Fully

tested in a factory (hydraulic and electric tests, outflow check, automatisation...), as per

quality management system standards. In addition, for easier and direct mounting without

construction works, it should be supplied with a solution for quick plug in and operation

(plug&play).

The device includes the following components:

SUBMERSIBLE PUMP: one (1) submersible pump for wastewaters, produced by stainless still

A/INOX, propulsion pump for transition of free solid substances up to 50 mm, engine power

of 1.2 kW, engine insulation of class F and IP68 protection, high efficiency IE3, plugged in

system for automatic plug in using mechanism for fixation and handling for easy installation

and maintenance. Characteristics of a pump with sufficient density and pressure to ensure

continuous flow throughout the station and flow of re-circulation which returns back to the

reservoir for homogenisation, thus enabling continuous and efficient fusion of raw water. It

should be installed into the homogenisation tank (out of scope).

FUSION HOMOGENISATION SYSTEM is included of organic loading and flow regulation.

DETAILED THOROUGH RECORDING: one (1) self-cleaning dynamic rotation tank to filtrate

liquid or for sifting and dehydration of solid substances, with processing capacity of 56 m3/h,

manufactured with stainless steel A/INOX 316L, at a distance of 3 mm, engine power of 0,18

kW, self-cleaning system with double rake and automatic cleaning with indoor and outdoor

water pressure injection.

BIO REACTORS WITH HIGH AND MEDIUM-SIZE COMPRESSION, frame profiles and sheet

metals manufactured from carbon steel, with width of 4 mm, inlay with welded and

imprinted FRP and 4-layer outlay (abrasive cleaning of the metal surface, epoxide and

polyester enamel, final layer with imprinting treatment), with removable covers, including

manholes to check reactors and valves for drainage of tanks.

The reactors are filled up with 70% volume of CARRIERS, manufactured from high density

polyethylene (HDPE), with minimum specific surface of 650 m2/m3.

The bio reactors include OXYGENISATION SYSTEM, consisted of blower with one (1) one-

level canal, produced by cast aluminium, 5,5 kW power, motor insulation of class F and IP55

protection, available high efficiency IE2, integrated heat protection, used with changeable

speed drive, as deemed necessary.


AIR DISTRIBUTION SYSTEM with steel pipe while emptying the blower, self-regulation

system with pressure and flow, to enable air with homogenous diffusion, oxygen injected

efficiently into a fused liquid for optimum control of oxygen concentration into the treated

volume.

LAMELLA CONE-SHAPE DECANTER (SEDIMENTATION TANK), profiles of frame and metal

sheet manufactured from carbon steel, with width of 4 mm, inlay with welded and imprinted

FRP and 4-layer outlay (abrasive cleaning of the metal surface, epoxide and polyester

enamel, final layer using imprint treatment), with removable covers, including manholes to

check the tanks and valves for reservoir drainage.

LAMELLA CLARIFIER produced from PVC, with specific surface of 6,25 m2/m3 and with raked

panel under a 60° angle, to improve the sediment separation.

One (1) SYSTEM FOR FLOCULENT DOSAGE (substance improving the collection of particles,

especially for wastewater treatment) is included to improve sediment decantation

(separation of substances that are not degradable into water and which are composed of

larger particles), consisted of one (1) peristaltic dosage pump with 4-20 mA, ppm, pulsing

and manual function, IP65 protection, one (1) polyethylene tank of 50L and one (1) fusion

system.

One (1) SEDIMENT EXTRACTION SYSTEM is included, with one (1) submersible pump to lay

down sediment, manufactured from stainless steel A/INOX, drive pump containing corridor

for transition of free solid substances up to 50 mm, engine power of 1.2 kW, engine

insulation of Class F and IP68 protection, high efficiency IE3, system is included for automatic

plug in with mechanism for attaching and handling for easy installation and maintenance.

CONTROL BOOTH, profiles of frame and metal sheet produced from carbon steel, with width

of 2 mm, 4-layer indoor and outdoor foundation (abrasive cleaning of the metal surface,

epoxide and polyester enamel, final layer by using imprint treatment), with two (2) access

doors, with lock system assembled, with ventilation system. Inside the control booth, there

are electric locker, blower and dosage system installed.

INSTRUMENTATION composed of one (1) electro-magnetic flow measurer without movable

part, with signal of 4-20 mA, PN10-16 and max.: Tº 80ºC, IP65 protection, for fast

measurement and fully clarified water during the flow. Circuit breakers for the operation

level, with start/stop buttons and for protection of electro-mechanic equipment.

ELECTRIC BOOTH made of carbon steel with anti-corosion layer, with simplex current,

transformer, circuit breakers, RCD protection (device for residual current), starters, relays

and contactors, circuit breakers for switch off and urgent switch off button, emergency kit

and cables for proper installation, pursuing the standards.

MANAGEMENT AND AUTOMATISATION SYSTEM, including PLC and HMI touch panel, with

special vigilance software, history recording, alarms and alerts and automatic control of the

submersible pump, sediment pump, detailed thorough recording system for oxygenisation,


with communication protocol with the central management system and available remote

control.

For the required operation capacity, one (1) plant was envisaged. To protect buildings from

river outflow, anchoring central plants with concrete panels was envisaged.

It is recommended that the Investor develops project documentation related to the

protection of the plant from water outflow from the riverbed (e.g. embankments, support

walls, or alike).

Following the treatment in the container plants, the sediments is headed into a sediment

density basin 10m3, and the clean water is discharged into the recipient. The dense

sediment from the basin is periodically transported with a cistern to an external site.

The entire upurified water (from outflows, discharge, etc.) is returned back to the pump

station, where it is sent back in the purification process.

The plant is automates and works without supervision. The Operator should periodically add

the needed chemicals (polymers) necessary for condensation of sediments.

SOURCE: Sanitary wastewater – wastewater coming from residential areas.

Basic characteristics:

• High level of suspended substances

• High level of organic matters

• High level of microbiological activities

• Content of fats and oils, max. 50 mg/l

QUALITY: The wastewater characteristics are equalised with the communal water

composition.

Book of Regulations on the conditions, manner and limit values of the discharge emission of

wastewaters after their purification, the manner of their calculation, given the special

requirements for conservation of protected areas (Official Gazette of RM nr. 81/11).

The adopted quality of collection sanitary-faecal wastewaters, if compared to the quality of

wastewater that is allowed to be discharged into the recipient, indicates that during the

purification treatment, it is of utmost importance to reduce the content of specific

substances.

Table. Comparative parameters for necessary level of purification

Parameter

Expected

concentration into

the wastewater

Limit values of

emission

Required level of

purification RLP (%)

pH 7,0 6,5 – 9,0 /

Temperature / 30 /


Suspended substances 367 35 90.5%

Deposit / 0,3 /

HPK 800 125 84,3%

BPK 400 25 93,8%

Total of fats and oils 120 20 83,3%

Total of chlorine 0 0,4 0%

Total of nitrogen 70 10 85,7%

Ammonia nitrogen 40 10 75%

Total of phosphorus 16 2 87,5%

Basic structure of planned solution consists in the following components:

1. Egalisation reservoir V=50m3, made of reinforced concrete.

2. Compact container plant consisted of the following processes:

• Raw wastewater pump

• Fine automatic grid

• Biological reactor MBBR

• Dosage of flocculants

• Lamella separator

• Density basin and supplementary sediment stabilisation.

Based on the quality criteria of purified water and expected characteristics of raw

wastewater, selective and gradual process is recommended, ensuring efficient elimination of

pollution and maximum perseverance of installed equipment.

The central plant is a device relying on MBBR technology.

MBBR reactor is adaptable and flexible solution assisting the users to achieve requested

objectives. The MBBR process is based on floating biofilm carriers, which are in continuous

movement under aeration conditions inside the reaction reservoir. The biofilm carriers

ensure protected surface for growth and development of heterotrophic bacteria (those

using organic bounded carbon for their growth) and autotrophic bacteria (those using non-

organic bounded carbon) inside the cells. Compared to the traditional treatment manner,

this method requires less maintenance and considerably smaller space. Not needing return

of active sediment in the process, the operation is considerably simplified, and the process

efficiency is considerably increased.

Basic features:

• Compact wastewater treatment plant

• Moving Bed Biological Reactor (MBBR)

• Modular implant, simple to transport and superstructure

• The installation is above the earth level

• Automatic operation.


BASICS OF THE SYSTEM OPERATION

The MBBR process is relying on floating biofilm carriers, which are in constant movement

under aeration conditions inside the reaction reservoir. The biofilm carriers ensure

protected surface for growth and development of heterotrophic bacteria (those using

organic bounded carbon for their growth) and autotrophic bacteria (those using non-organic

bounded carbon) inside their cells. Compared to the traditional treatment manner, this

method demands less maintenance and considerably smaller space. Not needing return of

active sediments into the process, the operation is considerably simplified, and the process

efficiency is considerably increased.

Table. Comparison with the active sediments process

MBBR Process with active sediments

Microorganisms are attached on carriers

(biofilm)

Biomass concentration: 9.000 mg/l

Biofilm density is formed depending on the

organic compression

No re-circulation of sediment is needed.

Microorganisms are suspended into the

mixture

Biomass concentration: 2.500 – 3.500 mg/l

Intervention is necessary from an Operator

when the organic compression is changed.

Re-circulation of sediments is needed.

Image. Technological process scheme

Wastewater Treatment Project in the village of Novo Konjarevo, Municipality of Novo Selo

Image. Detailed technological process scheme


The wastewater treatment includes the following processes:

The pump positioned in the egalisation reservoir has been continuously supplying the process

with wastewater in a unified composition. In front of the entrance into the MBBR reactor, large

dirt is removed using colanders. The reactor contains a filling space populated with active

biomass, and the reactor itself constructively adjusts the process conditions. Removing the

extra sediments from the purified water is ensured with the lamellas of the separator, and the

sediments are transported using a sediment pump. Thanks to the high level of purification, the

effluent from the plant may be discharged into the natural watercourse, as it was aligned with

all the quality standards.

Characteristics of the MBBR plant for wastewater treatment:

• The biomass is developed on the carriers, which are in the suspended water mixture.

• Large surface compared to the volume: 650m2/m

3

• It was designed to guarantee transfer of oxygen and organic substances

• The biofilm density is controlled and maintained by continuous separation happening under the

influence of aeration and fusion

• The material of carriers cannot be damaged – there are plants that are old even 20 years, and

still using same carriers

• The two-level biological process (high and medium-size compression) enhances the efficiency

and adaptation in fluctuating inflow of raw water

• The ratio of capacity/space occupying the plant is maximised

• High flexibility in the operation: from 30% - 70% share of carriers in relation to the reservoir

volume.

Table. Efficiency of MBBR device depending on the quantity of the fill

Treatment efficiency Loading (g BPK5/m2 day)

75 – 80 %

80 – 85 %

85 – 90 %

90 – 95 %

95 – 100 %

20,0

10,0

6,0

4,5

2,5

Image. Fill of a biological reactor MBBR


Operation and maintenance:

• No qualified staff is needed

• Sediment production: 0,35 kg dry matter / kg HPK

• Reduced consumption of chemicals (necessary flocculants for clearance 2-4 ppm)

The plant includes:

• Reservoir for alignment of the wastewater composition, concrete, digged in. There are

wastewater pumps placed in the basin.

• Wastewater submersible pump

o Submersible pump made of stainless steel for water with dirt up to 50mm, equipped for

assembling and easy handling.

• Fine colander

o Automatic rotation colander with porosity of 3mm made of stainless steel.

• MBBR aerobe biological reactor

o Biological reactor (for high and medium-size stress), made of steel panels with width of

4mm, and FPR coating, and outdoor anticorrosive coating. Carriers included (filling in

30% to 70% of the total reactor volume), aeration system with blowers and air

distribution throughout HDPE/PVC pipes.

o Operation parameters:

� Pressure of raw water: 2 - 4 bars

� Outdoor temperature: 0 – 40 °C

� Water temperature: 5 – 30 °C

� Above-see-level height: 230m

� Content of fats and oils: max. 50 mg/l

• Flocculants dosage to split sediments from the cleaned water. Poly-electrolyte is highly anion

electrised and is dosed in the secondary depositor in a concentration of approximately 2.00

mg/l.


• Lamella depositor

o Depositor made of steel panels with height of 4mm and FPR spread, and anti-corrosion

spread from the outdoor. Pack of lamellas for larger surface of PVC and dosed system

with flocculants for sediment conduction.

• Sediment discharge.

o Submersible pump made of stainless steel for cleaning wastewater from dirt of 35-

50mm equipped for assembling and easy handling.

• Sediment densification is done in the depositor with cone-shape bottom, with volume of 10m3,

one for each installed treatment line. The depositor is digged in right after the container plant.

• Automatisation

o PLC with touch screen and special programme to handle the plant. Monitor and control

of the pressure and watercourse.

• Electro-panel and receptacles.

o Metal locker with transformer, circuit breakers and engine starters. It covers conduct of

electro-distributor and electro-mechanical equipment.

• Standardised housing unit

o The entire needed equipment is assembled in the container housing unit.

section 11 – technical specification itb 21-2017 english

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