RO

AUTOMATIC MODULES FOR DRINKABLE WATER USING ADVANCED OXIDATION PROCESSES AND BIOFILTER (MULTIPLE BARRIERS)

ACRONYM: MULTIBAR

KEYWORDS: drinking water, multiple oxidants, advanced oxidation-AOP, electrochemical treatment

 

Project objectives:

The project proposes development of innovative technological systems for the treatment of surface and underground water which contain various pollutants such as: iron ions, hydrogen sulphide, arsenic, manganese, ammonium, nitrites, nitrates, humic acids, pesticides, herbicides, petroleum products, residues of drugs and cosmetics. Water is an essential substance of life. Any form of life can`t be conceived without water. Water is necessary for both humans, animals and the plants. Ensuring the necessary water (both in terms of quantity, but also quality) is essential for civilized life. Functionality of an economy (agriculture, industry, transport, etc.), the health of a society and its level of civilization depend on providing its necessary water. Freshwater needs for humanity increase every year, although more and more rivers of waters unfit not only as sources of drinking water but also for animals and plants use. Besides natural factors (floods, storms, landslides, natural air and soil pollution), industrial and technical development in parallel with population explosion dramatically increase damage of water quality by pollution. Physical and chemical pollution affects most the water quality. Physical pollution may be: insoluble materials discharged in rivers (minerals, wood, etc.), radioactive contamination, etc. Sources of chemical pollution are: chemicals discharged in rivers and/or industrial wastewater (heavy metals processing enterprises, complex decreases the animal, canneries, etc.), synthetic organic chemicals (pesticides, detergents, oils, phenols, dyes, oils, fertilizers, household waste, etc.).

Project relevance

In late 2004, the ONU recognized that water is critical for sustainable ecological development, indispensable for human health and noticed that half of the population in developing countries still consume water of poor quality.

Problems about water pollution became a serious concern at a global scale, the impact of water pollution is more critical, because this is connected tight to human life and health. The water eutrophying substances like organic matter, nitrogen (nitrates, nitrites, ammonia) and phosphor are the most common pollutants from surface water and other waters. This chemicals are generated not just from daily activities, but also from agriculture, industrial activities and livestock. Drinking water currently used in human nutrition although satisfying a number of physical, chemical and organoleptic conditions that allow consumption, due to its micro-pollutants content in time may be a life-threatening. Due to the enhancing of water sources pollution, the applying of the results of scientific research become vital in order to find solutions to obtain a safe drinking water, which helps to ensure a healthy diet now and for future generations. Water sources from wide areas from Romania and  Eastern Europe (Banat, Romanian Plain, Moldova,  Bulgaria, etc.) are often polluted with nitrogen compounds (ammonia, nitrites and nitrates ) and iron, manganese and arsenic. Most  of the technologies considered safe and, therefore, used for the treatment of such kind of waters require complicated technological  systems, being expensive regarding the energy consumption (reverse osmosis, ultrafiltration) and require, also, highly trained personnel for the operation. This consideration make that in practice to be implemented more simple stages for the water treatment,  based primarily on oxidation and disinfection with chlorine products. Therefore, the parameters  of resulted drinking water  were  in most of the cases to the upper limit allowed by the laws (law of water no. 458/2002 modified through law no. 311/2004), but not all of  the consumers agreed with the water  quality parameters, moreover for the young children it is not recommended because it contains nitrates. The legislation allows the concentration of nitrates in drinking water to be 50 mg/L, but for a sanogena water nitrate concentration should not exceed 10 mg /L as expressed by Romanian Water Association, getting  a such drinking water from current sources of water is a strategic issue.

 

Proposed strategy

In order to resolve some of these problems, two of Romanian companies involved in the development  for the water treatment equipments, SC ICPE-BISTRITA SA si SC AQUATOR SA Buzau  initiate the project AUTOMATIC MODULES FOR DRINKABLE WATER USING ADVANCED OXIDATION PROCESSES AND BIOFILTER (MULTIPLE BARRIERS), acronym MULTIBAR. The main goal of this project is to design and develop new equipments for  drinking water treatment for improving the current drinking water quality. To resolve some of the problems regarding the analysis of water parameters and the problems related to obtaining and testing new   materials which will be used for water treatment equipment, the consortium included also University POLITEHNICA of Bucharest - ECO-Metallurgical Research and Expertise Center.  For modeling - simulation process, automation strategy and composition Technical University of Cluj-Napoca - Faculty of Automation and Computer Science joined, also, to the consortium.

Innovative technological systems hereby proposed have the scope to minimize energy consumption and maximize performance. The complexity of technological systems will be given by the number and concentration of pollutants in the water source used to provide drinking water. More general, the technology proposed will consist of a pressurized aeration step, a pre-oxidation step with oxidants obtained electrochemical, a bio-filtration step and a disinfection step. The electrochemical pre-oxidation step will be use the ozone as oxidation agent if the concentration of pollutants in raw water used for treatment require this, also ozone will be used as the final step for the water disinfection. Chemical pre-oxidation process consists on generating of active oxygen species (hydroxyl radicals, hydrogen peroxide) and chlorine within the processed water using the electrolysis with medium frequency pulse, so any pollutants dissolved in water to be oxidized and then retained in bio-filtration step. Depending on the concentration of pollutants from water the bio-filtration step will consist of one or two steps (based on filters in which are developed bacteria culture that consume pollutants from water). Its role is to make a filtration by adsorption and to maintain the nitrifying-denitrifying bacteria cultures, which consume nitrogen and organic carbon compounds with high efficiency, without removing the useful salts from the treated water (like calcium and magnesium) at low energy consumption.

 

 

Expected modules with a capacity of 10-30 m3/h, will be integrated in the hydraulic circuit of treatment plants and water distribution systems, with public or private use. The estimated types to be made ​​and implemented are shown in Table 1.

Table 1.Estimated types of modules for drinkable water obtained in the project

 

Nr.crt.

Module type

Maxim flow of treated water

Q

 (m3/h)

Power consumption

P

(kW)

1

MAPOx-10

10

2,50

2

MAPOx-20

20

4,50

3

MAPOx-30

30

5,50

 

 

 

 

 

 

 

 

 

The water treatment will be made without addition of supplementary chemical reagents, excluding those required by the rules regarding the ensuring the values for the concentration of the residual disinfectant (free chlorine).

            The estimated water quality to be obtained using this modules for drinking water treatment  is reflected in table 2, and its quality will be better than the legal recommendations  (Law of Water no. 458/2002 modified through Law no. 311/2004) in the case of respecting of raw water average  quality conditions.

 

 

Table 2. Pollutants reduction in drinking water by implementation of the modules resulted from the project

Nr.crt.

Parameter

Estimated concentration obtained at the module outlet

 (mg/L)

CMA

(Law 458/2002)

         (mg/L)

1

Ammonium

< 0,2

0,5

2

Nitrite

< 0,1

0,5

3

Nitrate

<  10

50

4

Oxidability (CCOMn)

<  3

5

5

Iron

< 0.1

0.2

6

Manganese

< 0.03

0.05

7

Aluminium

< 0.1

0.2

8

Sulphates

< 150

250

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 The advantages of the new technologies proposed are:

-          Increased safety of individual consumers because  in the drinking water treatment process will not be used chemical compounds which may generate toxic by-products

-          The reduction of disease incidence or epidemics caused by the possible induction of specific diseases by the consumption of water improperly processed, with results hardly quantifiable and major effects at the level of whole categories of people (especially children).

-          The reduction of cost generated by avoiding of use   expensive methods for water treatment   or of the use of long distance raw water sources.

-          Reduction of accidental pollution caused by improper handling of chemicals used for drinking water. The risk is practically zero because all the oxidants are generated "in situ".

 

The project will be run according to the following chart:

WP 1: Comparative study of multiple barriers used in the drinking water;

WP 2: Execution of functional model of drinking water plant, technical and economic analysis

WP 3: Prototype design, realization of feasibility study

WP 4: Prototype execution

WP 5: Prototype testing, validation and certification.

 

 

 

Summary of stage 1