Environmental Engineering
E.N. Hidayah; R.B. Pachwarya; O.H. Cahyonugroho
Abstract
BACKGROUND AND OBJECTIVES: The existence of organic matter is one of the main issues for wastewater reclamation since chlorination is applied most frequently before use wastewater reclamation for many purposes. One of the eco-friendly and effective methods is using innovative material through resin immobilized ...
Read More
BACKGROUND AND OBJECTIVES: The existence of organic matter is one of the main issues for wastewater reclamation since chlorination is applied most frequently before use wastewater reclamation for many purposes. One of the eco-friendly and effective methods is using innovative material through resin immobilized heterogeneous photocatalyst, which is based on the principle of advanced oxidation processes. Resin immobilized photocatalyst has been using for pollutant reduction, however lack of studies focused on dissolved effluent organic matter and its impact on the formation carcinogenic as by-product of water or wastewater treatment. This study aims to characterize organic matter by resin immobilized photocatalyzed titanium dioxide and zinc oxide and to determine its effectiveness in removing organic matter and potential for disinfection by-products in treated wastewater compare with resin only.METHODS: The bulk parameters, including total organic carbon, aromatic organic carbon as ultraviolet at 254 nm wavelength and specific ultraviolet absorbance value, and disinfection by-products formation potential, including trihalomethanes and haloacetic acids concentration was measured.FINDINGS: The results present that all materials could remove organic carbon in the range 58.18% - 93.45%, aromatic organic carbon removal 48.77% - 76.51%, and specific ultraviolet absorbance value decreased into less than 2 L/mg-m after longer contact time. Disinfection by-products formation potential concentration removal decreased and indicated the consistency results with bulk parameters removal. Resin immobilized photocatalyzed zinc oxide performed a higher efficiency removal than resin immobilized photocatalyzed titanium dioxide and resin only.CONCLUSION: This study exhibited the performance of resin immobilized photocatalyst with titanium dioxide and zinc oxide in removing dissolved organic matter and to control the formation of disinfection by-products. A combination between bulk parameters and disinfection by-products formation potential removal concluded that the aromatic structure, was mainly haloacetic acids precursors, while the non-aromatic organic fraction was probably trihalomethanes precursors.
E.N. Hidayah; W.L. Lai; O.H. Cahyonugroho; F. Rizqa
Abstract
A combination of high performance size exclusion chromatography with organic carbon detector and ultraviolet detector coupled with peak-fitting technique and fluorescence excitation-emission matrix spectrometry applied fluorescence regional integration method was conducted to determine the characteristics ...
Read More
A combination of high performance size exclusion chromatography with organic carbon detector and ultraviolet detector coupled with peak-fitting technique and fluorescence excitation-emission matrix spectrometry applied fluorescence regional integration method was conducted to determine the characteristics of organic matter during nitrification. The batch scale of bionet nitrification without organic carbon substrate under aerobic conditions was operated for around 150 minutes. Bulk organic parameters and NH4+-N concentration were analyzed. Five different molecular weights of organic matter were identified by using chromatography, and five different groups of fluorophores organic fractions detected by fluorescence. According to chromatography with carbon and ultraviolet detector, the main characteristics of organic matter shifted from building blocks aromatic compounds with percentage peak area of carbon/ultraviolet detector: 31%/53% to 14%/27.5% to humic-like substances with percentage peak area of carbon/ultraviolet detector 21%/17% to 27%/46.5% during nitrification. Those former compounds are biodegradable as well as properties of microbial products released during substrate utilization and endogenous phase, which are mainly identified as humic-like substances, thus underwent further biodegradation. However, there was significant change in the fluorophores organic fractions, which exhibited humic acid-like with percentage fluorescence regional index area 53% into 68%, as shown by fluorescence excitation-emission matrix analysis. A combination of these methods indicated that the organic matter released during nitrification mainly consists of humic compounds. These results conjecture that a combination of high performance size exclusion chromatography with carbon and ultraviolet detector and fluorescence excitation-emission matrix can be used to determine the characteristic of organic matter and water quality change during nitrification.
