Chloride or sulfate? Consequences for ozonation of textile wastewater

Ozonation of chloride-rich textile wastewater is a common pretreatment practice in order to increase biodegradability and therefore meet the discharge limits. This study is the first to investigate ozone-chloride/bromide interactions and formation of hazardous adsorbable organic halogens (AOX) in real textile wastewater. Initially effect of ozonation on chloride-rich real textile wastewater samples were investigated for adsorbable organic halogens (AOX) formation, biodegradability and toxicity. After 15 min of ozonation, maximum levels of chlorine/bromine generation (0.3 mg/l) and AOX formation (399 mg/l) were reached. OUR and SOUR levels both increased by approximately 58%. Daphnia magna toxicity peaked at 100% for 10 min ozonated sample. Considering adverse effects of ozonation on chloride-rich textile industry effluents, we proposed replacement of NaCl with Na2SO4. Comparative ozonation experiments were carried out for both chloride and sulfate containing synthetic dyeing wastewater samples. Results showed that use of sulfate in reactive dyeing increased biodegradability and decreased acute toxicity. Although sulfate is preferred over chloride for more effective dyeing performance, the switch has been hampered due to sodium sulfate's higher unit cost. However, consideration of indirect costs such as contributions to biodegradability, toxicity, water and salt recovery shall facilitate textile industry's switch from chloride to sulfate.TUBITAK (117Y194

Investigation of heavy metals and ammonia inhibition on anaerobic reactor

ANAEROBİK REAKTÖRDE AĞIR METALLER VE AMONYAK İNHİBİSYONUNUN İNCELENMESİ Katı atık yönetimi artan nüfus ve kontrol edilemeyen kentleşme ile birlikte tüm dünyada önemli bir çevre problemi haline gelmiştir. Katı atıkları düzenli depo sahalarına depolamak son ve ucuz bertaraf yöntemidir. Fakat depo sahalarında oluşan sızıntı suları çözülmesi gereken başka bir problemdir. Katı atık düzenli depo sahası sızıntı suyu her zaman arıtımını zorlaştıran yüksek miktarlarda organik ve inorganik atık içerir. Yüksek kirlilik yüklerini deşarj limitlerine kadar azaltmak için birleşik biyolojik ve kimyasal arıtma metotları kullanılması gerekir. Anaerobik parçalanma yüksek organik karbon yüklerinin giderimi için ideal bir metottur. Fakat birçok inhibitör madde prosesin kararlılığını ve metan üretimini olumsuz etkilemektedir. Yüksek serbest amonyak konsantrasyonu ve ağır metaller anaerobik arıtımda inhibisyonun birincil sebepleridir. Literatürde anaerobik arıtımın inhibisyonu hakkında birçok çalışma yapılmasına rağmen, inhibisyona neden olan maddeler hakkında hala bilinmeyen birçok şey bulunmaktadır. Bu çalışmada İstanbul Kömürcüoda Katı Atık Düzenli Depo Sahasından gelen sızıntı suyu yukarı akışlı çamur yatağı (YAÇY) reaktör ile 600 gün arıtılmıştır. Reaktörün aşılanmasından sonra, giriş amonyak konsantrasyonu anaerobik arıtımda serbest amonyak etkisini gözlemlemek için 100 mg/L den 2800 mg/L ye kademeli olarak arttırılmıştır. Amonyak konsantrasyonu arttırılırken, KOİ ve BOİ giderim verimleri %95 ten %15 e kadar kademeli olarak azaldı. Anaerobik bakteriler amonyak konsantrasyonuna adapte edilmelerine rağmen, amonyağın inhibitör etkisi 1000 mg/L amonyak konsantrasyonunda gözlemlendi. ABSTRACT INVESTIGATION OF HEAVY METALS AND AMMONIA INHIBITION ON ANAEROBIC REACTOR Solid waste management has been an important environmental problem with the increase of population and uncontrolled urbanization throughout the world. Storage of solid wastes in the landfill is the final and cheaper disposal method. However leachate originated from landfills is another problem that should be solved. Landfill leachate always contains high amounts of organic and inorganic waste which make its treatment hard. Combined biological and chemical treatment methods should be used to reduce high pollution loads to the discharge limits. Anaerobic digestion is the ideal method for removal of high organic carbon loads. However many inhibitory substances adversely affect the process stability and methane yield. High free ammonia concentration and heavy metals are primary cause of inhibition in anaerobic treatment. Although in literature many studies were made about inhibition of anaerobic treatment, there are many things still unknown about inhibitory substances. In this study leachate coming from Istanbul Komurcuoda Landfill was treated with upflow anaerobic sludge bed (UASB) reactor for 600 days. After inoculation of reactor, influent ammonia concentration was gradually increased from 100 mg/L to 2800 mg/L in order to observe the free ammonia effect on anaerobic treatment. COD and BOD removal efficiencies decreased gradually from 95% to 15% while ammonia concentration was increased. Although anaerobic bacteria have been adapted to ammonia concentration, inhibitory effect of ammonia was observed at 1000 mg/L ammonia concentration

Investigation of heavy metals and ammonia inhibition on anaerobic reactor

ÖZETANAEROBİK REAKTÖRDE AĞIR METALLER VE AMONYAK İNHİBİSYONUNUN İNCELENMESİKatı atık yönetimi artan nüfus ve kontrol edilemeyen kentleşme ile birlikte tüm dünyada önemli bir çevre problemi haline gelmiştir. Katı atıkları düzenli depo sahalarına depolamak son ve ucuz bertaraf yöntemidir. Fakat depo sahalarında oluşan sızıntı suları çözülmesi gereken başka bir problemdir. Katı atık düzenli depo sahası sızıntı suyu her zaman arıtımını zorlaştıran yüksek miktarlarda organik ve inorganik atık içerir. Yüksek kirlilik yüklerini deşarj limitlerine kadar azaltmak için birleşik biyolojik ve kimyasal arıtma metotları kullanılması gerekir. Anaerobik parçalanma yüksek organik karbon yüklerinin giderimi için ideal bir metottur. Fakat birçok inhibitör madde prosesin kararlılığını ve metan üretimini olumsuz etkilemektedir. Yüksek serbest amonyak konsantrasyonu ve ağır metaller anaerobik arıtımda inhibisyonun birincil sebepleridir. Literatürde anaerobik arıtımın inhibisyonu hakkında birçok çalışma yapılmasına rağmen, inhibisyona neden olan maddeler hakkında hala bilinmeyen birçok şey bulunmaktadır. Bu çalışmada İstanbul Kömürcüoda Katı Atık Düzenli Depo Sahasından gelen sızıntı suyu yukarı akışlı çamur yatağı (YAÇY) reaktör ile 600 gün arıtılmıştır. Reaktörün aşılanmasından sonra, giriş amonyak konsantrasyonu anaerobik arıtımda serbest amonyak etkisini gözlemlemek için 100 mg/L den 2800 mg/L ye kademeli olarak arttırılmıştır. Amonyak konsantrasyonu arttırılırken, KOİ ve BOİ giderim verimleri %95 ten %15 e kadar kademeli olarak azaldı. Anaerobik bakteriler amonyak konsantrasyonuna adapte edilmelerine rağmen, amonyağın inhibitör etkisi 1000 mg/L amonyak konsantrasyonunda gözlemlendi.ABSTRACTINVESTIGATION OF HEAVY METALS AND AMMONIA INHIBITION ON ANAEROBIC REACTORSolid waste management has been an important environmental problem with the increase of population and uncontrolled urbanization throughout the world. Storage of solid wastes in the landfill is the final and cheaper disposal method. However leachate originated from landfills is another problem that should be solved. Landfill leachate always contains high amounts of organic and inorganic waste which make its treatment hard. Combined biological and chemical treatment methods should be used to reduce high pollution loads to the discharge limits. Anaerobic digestion is the ideal method for removal of high organic carbon loads. However many inhibitory substances adversely affect the process stability and methane yield. High free ammonia concentration and heavy metals are primary cause of inhibition in anaerobic treatment. Although in literature many studies were made about inhibition of anaerobic treatment, there are many things still unknown about inhibitory substances. In this study leachate coming from Istanbul Komurcuoda Landfill was treated with upflow anaerobic sludge bed (UASB) reactor for 600 days. After inoculation of reactor, influent ammonia concentration was gradually increased from 100 mg/L to 2800 mg/L in order to observe the free ammonia effect on anaerobic treatment. COD and BOD removal efficiencies decreased gradually from 95% to 15% while ammonia concentration was increased. Although anaerobic bacteria have been adapted to ammonia concentration, inhibitory effect of ammonia was observed at 1000 mg/L ammonia concentration

Recovery of Biologically Treated Textile Wastewater by Ozonation and Subsequent Bipolar Membrane Electrodialysis Process

The Bipolar Membrane Electrodialysis process (BPMED) can produce valuable chemicals such as acid (HCl, H2SO4, etc.) and base (NaOH) from saline and brackish waters under the influence of an electrical field. In this study, BPMED was used to recover wastewater and salt in biologically treated textile wastewater (BTTWW). BPMED process, with and without pre-treatment (softening and ozonation), was evaluated under different operational conditions. Water quality parameters (color, remaining total organic carbon, hardness, etc.) in the acid, base and filtrated effluents of the BPMED process were evaluated for acid, base, and wastewater reuse purposes. Ozone oxidation decreased 90% of color and 37% of chemical oxygen demand (COD) in BTTWW. As a result, dye fouling on the anion exchange membrane of the BPMED process was reduced. Subsequently, over 90% desalination efficiency was achieved in a shorter period. Generated acid, base, and effluent wastewater of the BPMED process were found to be reusable in wet textile processes. Results indicated that pre-ozonation and subsequent BPMED membrane systems might be a promising solution in converging to a zero discharge approach in the textile industry