Evaluation of algae related taste and odor problem in drinking water

Abstract

İçme suyu, su kaynağından tüketici musluğuna ulaştırılana kadar birçok aşamadan geçmektedir. Suyun kalitesi; su kaynağındaki su kalitesine, arıtma tesisinde uygulanan proseslere ve su dağıtım şebekesinin durumuna bağlıdır. Arıtılmış suda istenmeyen tat ve koku, tüketicideki içilebilir su algısını etkilemekte ve tüketicinin musluk suyu tüketimi ile sağlık riskini ilişkilendirmesine sebep olabilmektedir. Bu durum, su temini tesislerine olan tüketici güveninin azalmasına yol açabilmektedir. Söz konusu sorunun çözümü için su otoritelerince sorunun kaynağı araştırılmakta, buna eş zamanlı olarak arıtma tesislerine kolay entegre edilebilecek sistemler üzerinde çalışılmaktadır. Bu bağlamda, havzada sorunun kaynağının tespiti ve sonrasında alınacak önlemler büyük önem taşımaktadır. Ayrıca su arıtma tesislerinde tesis işletiminden kaynaklanan tat ve kokunun önüne geçilmeye çalışılmakta, bunun yanısıra 10 ng/L konsantrasyonun altında bile insanlar tarafından algılanabilen 2-MIB ve Geosmin bileşiklerinin oksidasyon, adsorpsiyon veya biyofiltrasyon gibi proseslerle giderimi incelenmektedir. Öte yandan, arıtılarak şebekeye verilen suda biyolojik aktiviteden veya dezenfeksiyon yan ürün oluşumundan kaynaklanan tat ve koku oluşumu da önlenmelidir. Bu çalışmada, suyun havzadan musluğa yolculuğu boyunca suda oluşabilecek tat ve koku probleminin etmenleri ve bu soruna yönelik çözüm yolları incelenmiştir. Source water goes through several processes before reaching to the customer's tap. Quality of water which flows through the tap is directly related to the water quality in the reservoir, processes used in the drinking water treatment plant and the condition of the present distribution system. Taste and odor in the treated water affects the perception of the drinking water for the customers and causes them to relate it with health risks. This results with a decline in consumer reliance to the water supply system. Water authorities are not only searching for the cause of the problem, but also trying to find a solution which can be integrated to the existing Water Treatment Plant system. In this context, problems related with watershed should be determined and precautions should be taken based on these issues. In WTP's, taste and odor problem caused by wrong plant operations should be avoided while treatment processes such as oxidation, adsorption and biofiltration processes should be tested for the removal of 2-MIB and Geosmin which can be percieved by the humanbeings even at 10 ng/L. Also, taste and oodor occurance in treated water caused by biological activity or DBP's in distribution systems should be avoided. In this study, potential causes of taste and odor occurance during the travel of water from reservoir to consumer's tap is stated along with the solutions.

Analysis of Eutrophication Potential in Main Drinking Water Basins of Istanbul

“…The compounds produced by algae such as geosmin and 2‐methylisoborneol have been detected at levels well above threshold concentrations (10 ng L –1 ) impacting end users. [ 7 ]…”

The First Report of Geosmin and 2-Methylisoborneol Producer Cyanobacteria From Turkish Freshwaters

“…In addition, as a response to environmental factors such as light, temperature etc., MIB production mechanism responds faster in hours while GEO production mechanism response can take days (Watson et al 2016, Watson & Jüttner 2019). The first challenge for monitoring and treatment studies is the estimation of GEO and MIB production time and concentration levels (Fakıoğlu et al 2018). The second challenge is the presence of different producer groups in the same habitat such as Cyanobacteria, Proteobacteria, Actinobacteria and Ascomycota (Mattheis & Roberts 1992, Dickschat et al 2005, Cane et al 2006, Watson et al 2016).…”

“…As one of the main producers, Cyanobacteria has a wide range of distribution in different water sources (lakes, reservoirs, rivers and marine environment) in Turkey (Akcaalan et al 2009, Akcaalan et al 2014a, Akcaalan et al 2014b, Koker et al 2017). Studies on their presence and toxin production have increased in recent years, but there is a limited number of studies on cyanobacteria-associated taste and odour problems (Albay et al 2009, Fakıoğlu et al 2018. In addition to this, MIB and GEO have been reporting in drinking water quality reports of İstanbul, especially in summer periods which consequently lead to costly water treatment projects based on granular activated carbon (İSKİ 2020).…”