Tekstil endüstrisi atık sularında membran proseslerle su geri kazanımı ve konsantre giderimi için farklı teknolojilerin denenmesi
Testing of different technologies for concentrate of membrane treatment technologies in industrial waste water
Yazar: ALPER YAZAGAN
Danışman: DOÇ. DR. DERYA YÜKSEL İMER
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Çevre Mühendisliği Ana Bilim Dalı / Çevre Bilimleri, Mühendisliği ve Yönetimi Bilim Dalı
Derece: Yüksek Lisans, 2018
Konu: Çevre Mühendisliği = Environmental Engineering
Dizin: Elektrodiyaliz = Electrodialysis ; Elektrokoagülasyon = Electrocoagulation ; Membran teknolojileri = Membrane technologies

Özet:
Dünya nüfusunun artışı ile birlikte kaliteli ve yeterli miktarda suya erişim ihtiyacı günden güne önem kazanmaktadır. Sadece dünyada değil Türkiye'de de endüstriyel ve tarımsal faaliyetlerin artışı, dış göç, yaşam kalitesindeki yükseliş, iklim değişiklikleri ile yağışların azalması gibi nedenlerle su sıkıntısı kendini göstermektedir. Ülkemizde yaşanan su sıkıntısının giderilmesine yönelik alınacak önlemler arasında doğru su politikaları, yönetimi ve su arıtma teknolojilerinin kullanımı ön plana çıkmaktadır. 

Ülkemiz su kaynaklarının %13'ünün ayrıldığı sanayi içinde en yüksek  tüketim değerlerine sahip sanayi kollarından olan tekstil endüstrisinin su geri kazanımı da bu açıdan önem arz etmektedir. Tekstil endüstrisine ait proses atık suları, içerdikleri boya ve yardımcı kimyasal maddelerin kompleks yapısı nedeniyle genellikle toksik olup, biyolojik olarak ayrışmaya karşı dirençlidirler. Bu nedenle tekstil atık suyu arıtımı yapılan arıtma tesislerinin çıkış sularında boya veya kompleks organik maddeler bulunabilmektedir ve bu sular alıcı ortama deşarj edildiğinde önemli çevresel sorunlar oluşmaktadır. Dolayısıyla gerek harcadığı su miktarı ve gerekse alıcı ortama etkileri sebebiyle tekstil atık sularının arıtımı, çevre kirliliği kontrolünde büyük önem taşımaktadır.

Konvansiyonel arıtım yöntemleri boya ve benzeri kirlilikleri gidermede çok etkin değillerdir ve özellikle su geri kazanımının düşünüldüğü alanlarda istenilen performansları gösterememektedirler. Bu nedenle yeni ya da konvansiyonel sistemleri destekleyecek ek sistemlerin geliştirilmesi konusu özellikle son yıllarda önemli bir çalışma alanı bulmuştur. 

Membran prosesler uzun zamandır tekstil endüstrisi atık sularının arıtımında başarılı bir şekilde kullanılmaktadır. Membran prosesler konvansiyonel yöntemler sonrası arıtılmış suyun ileri arıtımında ya da konvansiyonel prosesler öncesi ön arıtım için kullanılmalarının yanı sıra arıtılacak atık suya direkt olarak da uygulanabilmektedir. Membran proseslerle arıtılan tekstil atık sularının su kalitesi, özellikle nanofiltrasyon ve ters osmoz proseslerinden çıkan arıtılmış su, tekstil üretim prosesinde doğrudan kullanılabilir nitelikte olabilmektedir. Membran proseslerin bu yüksek su kalitesi, tekstil atık sularının arıtılıp deşarj edilmesindense, arıtılan suyun üretim prosesinde tekrar kullanılmasını gündeme getirmiştir. Bu yaklaşım hem temiz su kullanımı ihtiyacını hem de oluşacak atık su miktarını azaltacak önemli bir uygulamadır. Fakat membran proseslerin kullanımı sonucu oluşan konsantrenin yönetimi bu prosesin işletimi için oldukça önem arz etmektedir. Membran proseslerin uygulanmasındaki en büyük problem, proses sonucu açığa çıkan, kirlilik yükü son derece yüksek membran konsantreleridir. 

Bu çalışmada tekstil atık sularının membran prosesleri ile arıtımı ile ortaya çıkan konsantrelerin elektrofenton, elektrokoagülasyon ve elektrodiyaliz prosesleri ile arıtımı incelenmiş olup konsantre arıtımı performansları yorumlanmıştır.

Abstract:
Water is the foundation of life. Without water, life on Earth wouldn't exist at all. Acting as a medium in which organic compounds could mix with one another, water
facilitated the formation of the planet's first life forms, possibly even protecting them
from the sun's radiation. From those simple cells to the most complex plants and animals, water has played a critical role in nature ever since. In humans, it acts as both a solvent and a delivery mechanism, dissolving essential vitamins and nutrients from food and delivering them to cells. Our Bdies also use water to flush out toxins, regulate BOİy temperature and aid our metabolism. And it is not only we human race who need it; all life on earth depends on water to survive. 

In 20th century population and technological level incredebly rised. By itself rise in population resulted in much more water consumption but the major damage to earth is given because of technological rise. We consumed too much water, producted more stuff than we needed via consuming water , and polluted surface and subsurface water sources. More people lack drinking water today than they did two decades ago. More and more freshwater sources are being used-up and contaminated. Modern technologies have allowed us to harness much of the world's water for energy, industry and irrigation - but often at a terrible social and environmental price  and many traditional water conservation practices have been discarded along the way

The water crisis is the biggest global risk based on impact to society (as a measure of
devastation), and announced as #8 global risk based on likelihood (likelihood of occurring within 10 years) by the World Economic Forum, January 2015. 750 million people around the world lack access to safe water; approximately every one in nine people. More than twice the population of the United States lives without access to clean water. Diarrhea caused by inadequate drinking water, sanitation, and hand hygiene kills an estimated 842,000 people every year globally, or approximately 2,300 people per day. 82% of those who lack access to improved water live in rural areas, while just 18% live in urban areas. The problem of water scarity is a growing one. As more and more people put ever increasing demands on limited water supplies, the cost and effort to build or even maintain access to water will increase. And water's importance to political and social stability will only grow with the crisis.

With the increase in the world population, the need of accessing high quality and
adequate amount of water becomes very important. Because of increasing industrial
and agricultural activities, migration, standard of living, climate change and lack of
rainfall, the water shortage manifest itself not only in the world, but also in Turkey.
The usable water potential of Turkey is 110 billion m3 and 16% of it is consumed for
drinking and usage, 72% for agricultural activities and 12% for industrial activities.
In Turkey, annual average amount of water per person is 1430 m³ which makes it a
water poor country. General Directorate for State Hydraulic Works observed that our
water resources would be used 100% capacity in 2030. However, in 2030 Turkey's
population will exceed 80 billion and annual average amount of water per person will be decreased to 1100 m³ which makes the country facing the water shortage. In order to overcome the water shortage problem in our country, the use of water treatment technology as well as the implementation of the right water policies and management measures should be taken. Alternative solutions should be found for regions where no dams, lakes or rivers are absence. Every opportunity to recover water must be utilized, only that way we can have enough water for next generations. We must consider to improve urban wastewater treatment systems, industrial wastewater treatment systems and improve irrigation systems for farming.

Industry is the biggest potential that creates the environmental pollution. Managing industrial water usage is the main way to save water. Among industrial fields textile industry is one of the most water consuming ones. %13 of water in Turkey is used in industry and textile industry has a big share of it. Textile industry is categorized in varied industry branches with high water consuming and high waste water producing. During the industrial production and after different kinds of wastes come into being which causes environmental pollution. Production diversity in textile industry affects the waste water categorization. Textile industry includes different varieties of production proceseses causes waste water characteristics become so different and shows different consantrations in unit waste water amount. 
The water which is used at the poduction proses in the textile industry must be in a definite quality. The properties of the water used in textile fabrics directly affect the quality of the produced materials. It shows negative effect directly on the product quality if the water quality is not as it is needed. For this reason the quality of water is very important for preparing the ideal product. The waste water of textile industry is rather more coloured than the other industry branches because of the painting materials. The conventional treatment methods are unable to textile industry wastewater process due to the biologically resistant to decomposition of dyes and dye auxiliary chemical substances for thire complex structure.
In the aspect of water consumption textile industry is in a special place. It consumes large amount of water and it produces waste waters with different characteristics. Waste waters with very different characteristics are produced in textile industry, even so membrane technologies are an ideal way for treatment for this industry. Around world a lot of textile production factories started to prefer membrane technologies for water recovery. But despite all advantages membrane technologies present to  us, there are some handicaps. Membrane filtration technologies not only bring a solution to waste waters of textile industry but also create a new problem: Treatment of concentrate. With membrane technologies we create a cleaner stream and more polluted concentrate stream. This concentrate is very hard to treat and become a serious problem in applications. 
This study focused on concentrate treatment problem. For this study a textile factory's biological treatment facility's output water is taken and filtrated from ultrafiltration membrane. As a second and main process nanofiltration and reverse osmosis membranes are used with 80% water recovery rate after ultrafiltration process. Through these processes we achieved a concentrate of textile waste water to work on and also we had data to compare nanofiltration and reverse osmosis membrane processes' performances for textile industry waste water treatment. Nanofiltration and reverse osmosis filtration concentrates are treated with electrocoagulation and electrofenton processes. Electrocoagulation is a electro-physical process and  electrofenton is a electro-chemical process. They both are used to treat organic matter in concentrate.  Purpose of these processes was a preparation to electrodialysis. After this processes as final step of concentrate treatment, electrodialysis process is used. Performances of these processes are investigated in this study. Nanofiltration and reverse osmosis filtration technologies are compared. For concentrates of these processes, electrocoagulation and electrofenton processes are runned and their performances are compared. With electrocoagulation and electrofenton removal of organic matter is aimed. As final step of experiments, output of electrocoagulation and electrofenton processes are    used  in electrodialysis for salt removal. Four different combination of processes are investigated and compared in the study. These combinations are UF/NF/EC/ED, UF/NF/EF/ED, UF/RO/EC/ED and UF/RO/EF/ED. 
This study aimed to generate data on textile industry's membrane concentrate treatment via electocoagulation, electofenton and electrodialysis. Despite these processes are promising concentrate treatment methods, further research is needed.