Ak-Kim Produces the Region's First Water and Wastewater Membrane

Region's First Water and Wastewater Membrane – Ak-Kim Aqualys Ultrafiltration Modules and Ultrafiltration Technology

Introduction

Ak-Kim, Turkey's leading chemical producer, was established in Yalova in 1977 and has expanded its production activities across various locations in Turkey over time. Ak-Kim produces basic chemicals and performance chemicals and serves the cleaning, chemical, textile, paper, water treatment, food, metal, agricultural chemicals, energy, construction, mining, plastics and paints and coatings sectors. The company is a market leader in many products in the basic chemicals field and continues its growth by developing products and services for different sectors. Through its investment in ultrafiltration, the company has brought advanced treatment systems to the water treatment sector and has become the first and only producer of this product in Turkey. Ak-Kim entered a different market by bringing Gizem Frit, one of the world's largest producers of enamel and ceramic frits, into its portfolio in 2015. Serving customers in 70 countries worldwide, Ak-Kim incorporated the chemical sales and marketing company Dinox in Germany to stay close to its European market customers and continue its growth. Having taken over the remaining shares of Akferal, which it founded in equal partnership with Feralco in 2013 and subsequently incorporated Dostel into its portfolio, Ak-Kim made it 100% Ak-Kim subsidiary in November 2017. Leveraging its presence and synergy in the water treatment sector, Ak-Kim entered the advanced treatment technology sector through an investment in ultrafiltration membrane modules at its Yalova facility. With its modern factory that came on stream in 2016, it holds the position of first and only producer of this product in Turkey. Expanding its activities in water solutions with an Ultrafiltration Module manufactured using a formula developed in-house in 2015 and made from high-quality PVDF material with porous fibre, Ak-Kim is the sole company producing Ultrafiltration Modules in Turkey and the surrounding region.

Summary

Ultrafiltration (UF) is a purification process in which water is passed through a membrane and during this process, particles, colloids and macromolecules in the water are separated from the water. Ultrafiltration membranes provide high purification for bacteria, viruses, colloids and silt. Ultrafiltration is used in wastewater treatment, drinking water treatment, seawater pre-treatment, recovery of waste paint in the automotive and textile industries, beverage industry, reverse osmosis pre-treatment, and pre-filtration in surface waters such as dams, rivers, lakes, wells and rainwater. Ultrafiltration membrane modules used for different purposes can be manufactured from different materials. Membrane modules used for water treatment differ structurally from membrane modules used for paint in terms of raw materials and working principles. The common point of ultrafiltration membrane modules used for different purposes, manufactured from different materials and having different mechanical working principles is their filtration capability. All filters within the limits of particle filtration specified for ultrafiltration are referred to as ultrafiltration.

1. Introduction

Systems have been developed to meet the need for liquid filtration in the most efficient way. Ultrafiltration (UF), one of these systems, is a water treatment process in which water is passed through a membrane and during this process, particles, colloids and macromolecules in the water are separated from the water. It provides high purification for bacteria, viruses, colloids and silt. To meet the need for water filtration at optimal levels, filters produced with different levels of precision have varying pressure requirements. Systems are calculated and sized according to the intended application. The first step is to assess the outlet quality. Once the need is determined, the treatment system can be shaped. Generally, filtration precision is selected according to limit values, guided by the subsequent production system or the intended use of the treatment system.       Filtration technologies can be used for different purposes. In one process, while trying to separate particles from water to obtain water, in another process it can be used to concentrate valuable minerals in the water. Ultrafiltration, our main topic among these technologies, is used for different purposes. However, if the purposes are very different, ultrafiltration modules may have different structures to be compatible with the purpose. For example, ultrafiltration modules used in the car painting process differ in structure and material from ultrafiltration modules used for water treatment purposes. If a membrane module used to obtain clean water has certain technical specifications (for example, if its fibres are PVDF), it may be suitable for wastewater recovery.  

Figure 1.1 Ultrafiltration Membrane Module

   

2. Filtration Levels and Most Common Technologies 2.1. Filter Precision and Removals

Reverse Osmosis, Nanofiltration, Ultrafiltration, Microfiltration and Membrane Bioreactor membranes are the most commonly encountered filtration products in membrane systems.

Table 2.1

While Reverse Osmosis performs filtration at the ion level, Nanofiltration at the molecular level, Ultrafiltration performs filtration at the molecular and macromolecular level. In Microfiltration and broader pore filter systems, filtration is performed at the micro and macro particle level. Due to their very small pore filtration systems, pore sizes remain below observable levels. For this reason, filtration capacities are calculated in Daltons. Ultrafiltration modules generally perform filtration in the range of 100 to 150 kiloDaltons. For some special requirements, there are ultrafiltration membranes that perform precise filtration down to 30, 20, 15 and even 10 and 5 kiloDaltons levels. For example, in drinking water treatment, filtration at 100–150 kDaltons level is sufficient for virus and bacteria removal, while ultrafiltration modules used in dialysis systems are manufactured at 5 to 10 kDaltons precision for endotoxin removal.

2.2. Ultrafiltration Membrane

Ultrafiltration membranes are manufactured from different materials such as PVDF (Polyvinylidene-difluoride), PES (Polyethersulfone), PAN (Polyacrylonitrile), PS (Polysulfone). The most commonly used raw materials are PVDF and PES.

Figure 2.1

PVDF provides advantages over its competitors in terms of mechanical strength and chemical resistance. PVDF's high ability to be cleaned with chlorine creates great benefits for a system whose job is to trap bacteria. The fibre surfaces of ultrafiltration modules have asymmetric arrangement. Thanks to these characteristics, more efficient backwashing is achieved.

Figure 2.2 Asymmetric Surface

2.3. Application Fields

Ultrafiltration is used for wastewater treatment, drinking water treatment, seawater pre-treatment, waste recovery in industries such as textiles, beverage industry, reverse osmosis pre-treatment and filtration purposes in surface waters such as dams, rivers, lakes, wells and rainwater.

Figure 2.3 System Using Ak-Kim Aqualys Membrane Modules

Ultrafiltration membrane modules are used to produce natural water free of bacteria and viruses in drinking water treatment, produce water of quality suitable for industrial needs, protect systems producing process water from seawater, and recover and reuse wastewater in processes.

3. Flow Systematics

Ultrafiltration modules are divided into two types: dead-end and cross flow. Another distinction is in-to-out and out-to-in fibre flow designs.         3.1. Module Hydraulic Flow Types In dead-end flow, all water fed to the module is filtered and contaminants accumulate on the surface. In cross flow, a small amount (e.g., 5%) is discharged from the waste line or returned to the system inlet.     Figure 2.4    

Figure 3.1

3.2. Fibre Hydraulic Flow Types

There are two types of ultrafiltration fibre design: inside-to-outside and outside-to-inside flow. Systems in which dirty water flows from inside to outside are not suitable for wastewater treatment. Systems operating with outside-to-inside flow can work with both wastewater and clean water. Considering seasonal increases in water turbidity, "out to in" systems are the correct choice for difficult waters.

Figure 3.2

Figure 3.3

3.2.1. Salt and Particle Accumulation

Particularly in seawater systems, salt accumulation is an important problem. Improper backwashing can cause blockages. This problem is most often observed in systems operating inside-to-outside (in to out). Blockage occurs in the fibre mouth area. In systems operating outside-to-inside (out to in), dirty water does not reach the fibre mouth area and remains on the surface, spreading in a thin layer along the fibre until backwashing. Thus, it is removed from the system more easily with backwashing.

Figure 3.4

3.2.2. Pre-filters

Our pre-filter preference is pre-filters larger than 100 to 150 microns and smaller than 300 microns. Thus, particles entering the ultrafiltration membrane module are not of a single type and surface accumulation is cleaned more easily.

Figure 3.5 Pre-filter

3.2.3. Application Examples 3.2.4. Ak-Kim Aqualys Modules

They are actively used and building references in facilities producing fresh water from seawater, wastewater recovery facilities, city water network lines, making surface waters usable, producing clean water according to industrial needs and in wastewater treatment.

4. Conclusion

Ultrafiltration modules are preferred because they can operate at low pressure, can be backwashed (reverse flow) and can remove high levels of contamination. They make currently unusable waters usable. It is an effective solution for making unusable waters usable and for reuse of wastewater. Burak Dalkılıç Sales and Marketing Manager Water Solutions Ak-Kim Kimya Sanayi Ticaret A.Ş.