A large amount of water is used in the textile industry during the finishing and dyeing processes leading to the production of what is known as textile wastewaters. Textile wastewater is highly rich in COD and color and is characterized by relatively low biodegradability. This study aimed to investigate the treatability of reactive red dye-rich textile wastewater with the application of an airlift internal circulation membrane bioreactor (AIC-MBR). Experimentalresults demonstrated that high removal efficiencies of COD, NH3-N, and reactive red up to 99.70%, 97.83%, and 97.23%, respectively, can be achieved using the AIC-MBR system. Besides, EPS and SMP analyses reflected an SMP polysaccharide (PS) and protein (PN) membrane rejection that reached 88% and 72.6%, respectively. Finally, the capillary suction time measurement highlighted a good dewatering capacity of the sludge with a low membrane fouling tendency at the end of the operating period.

The main aim of this study is to investigate the feasibility of utilizing novel hydrotalcite-like-compounds as ionexchangers for the removal of anionic impurities from aqueous solution. Hydrotalcite is naturally occurring, rarelyfound anionic clay. It has a positively charged layered structure consisting of two metal oxide layers and an interlayerof carbonate anions. Hydrotalcites can, therefore, be used as ion-exchangers. However, the carbonate anion is highlyselected by natural hydrotalcite, making the ion-exchange capacity for other anions very low. In this study, severalsynthetic hydrotalcite-like compounds and a magnetic hydrotalcite-like compound samples were prepared in order toremove anionic impurities from waters. The physical structure and chemical properties of these anionic clays werecharacterized using standard characterisation techniques. The removal capacities of the synthetic products obtainedwere then investigated. Magnetic hydrotalcite-like-compound, namely, CaII-FeII-FeIII, was proved to be a good ionexchanger.

Günümüzde kaya gazı yeni bir enerji kaynağı olarak ele alınmakta ve kaya gazı ekstraksiyonuna yönelik araştırmalar tüm dünyada hız kesmeden devam etmektedir. Düşey ve yatay sondajın birlikte kullanıldığı ekstraksiyon çalışmalarında kaya gazının açığa çıkarılabilmesi için kaya formlarına yüksek hacimlerde basınçlı su enjekte edilmektedir. Kaya formlarına enjekte edilen suyun geri çekilmesi ile kullanılan suyun yaklaşık %10’u ila %80’i atıksu olarak karşımıza çıkmaktadır. Oluşacak atıksu hacmini minimize edebilmek için kaya gazı atıksuyunun ön arıtımı yapılarak ekstraksiyon çalışmalarında yeniden kullanımı son derece önemlidir. Diğer yandan kaya gazı atıksuyu yüksek miktarlarda toplam çözünmüş katı madde, ağır metal, hidrokarbon ve organik madde içerir ve bu nedenle atıksuyun deşarj edilmeden önce arıtılması gerekmektedir. Bu derleme çalışmasında kaya gazı ekstraksiyonunda kullanılan yöntemler ve ekstraksiyon esnasında üretilen atıksuyun özellikleri ve arıtım metodları irdelenmiştir. Kaya gazı atıksuyunun mekanik buhar kompresyonu ile buharlaştırılması, membran distilasyonu, ters ozmos, ileri ozmos, ileri kimyasal arıtma yöntemleri ve biyolojik arıtma yöntemleri ile arıtılabilirliği araştırılmıştır.

High concentrations of calcium present in paper mill wastewaters are considered as they lead to some important problems during the treatment process. Recently, submerged membrane bioreactor (sMBR) system have been commonly used to industrial wastewater treatment and it is observed that membrane scaling or fouling is one of the most important problems which causes many operational difficulties. A decrease in membrane flux is observed after the formation of CaCO3 film on the membrane surface as inorganic membrane fouling is encountered during the operation of the sMBR. Microbial carbonate precipitation (MCP) process is a natural microbial process and the mechanism of MCP is defined as the ability of microorganism to alkalinise an environment through various physiological activities. The purpose of this study was to investigate the application of MCP to paper-mill wastewater as a pre-treatment method prior to submerged membrane bioreactor. The potential for CaCO3 removal from wastewater through urea was investigated at optimum operation conditions obtained from the batch tests using a sequencing batch reactor (SBR). The optimum dosage of urea and HRT were determined 4 g/L and 72 h. The results obtained indicated that the calcium removal efficiency was found to be 90.16% at optimum experimental conditions in the SBR operation. It was found out that the MCP was a suitable method for calcium removal and it can be used as a pre-treatment method of paper-mill wastewater treatment to avoid calcium scaling and inorganic fouling in sMBR in the study.

This study deals with chemical oxygen demand (COD) removal from ceramic industry wastewater by chemicalcoagulation using alum and ferric chloride (FeCl3) as coagulants. The study also focuses on the capillary suction time(CST) of sludge samples which is an important sludge dewatering parameter. Response surface methodology (RSM)approach was employed to evaluate the effects and interactions of the operating variables and to optimize theperformance of the process. Significant quadratic polynomial models were obtained (R2 = 96.26% for alum andR2=89.15% for FeCl3 for COD removal; R2=96.6% for alum and R2=90.9% for FeCl3 for CST of sludge,respectively). Alum was found more effective coagulant for ceramic industry wastewater treatment as compared withFeCl3. Numerical optimization based on desirability function was employed; in a 36 min trial 95.2% of COD removalwas achieved at alum dosage of 3.3 g/L and pH 5. The optimization study shows that the minimum CST of sludgewas found 17.4 s at alum dosage of 5 g/L and pH 5 in a reaction time of 16 min. The results indicate that the RSM issuitable for the design and optimization of chemical coagulation process using alum as a coagulant for the treatmentof ceramic industry wastewater.