This study proposes the use of a cobalt-based Prussian blue analogue (Co-PBA; potassium cobalt hexacyanoferrate), as an adsorbent for the cost-effective recovery of aqueous ammonium ions. The characterization of Co-PBA involved various techniques, including Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, nitrogen adsorption-desorption analysis, and zeta potential. The prepared Co-PBA reached an adsorption equilibrium for ammonium ions within approximately 480 min, which involved both surface adsorption and subsequent diffusion into the interior. The isotherm experiment revealed a maximum adsorption capacity of 37.29 mg/g, with the Langmuir model indicating a predominance of chemical monolayer adsorption. Furthermore, the material consistently demonstrated adsorption efficiency across a range of pH conditions. Notably, adsorption was observed even when competing cations were present. Co-PBA emerges as a readily synthesized adsorbent, underscoring its efficacy in ammonium removal and selectivity toward ammonium.

The ion exchangers supported on silica gel containing primary, secondary, or tertiary amine groups show a behaviour that is weakly acidic, while the quaternary salts are strongly acidic. These properties change according to the hydrophilicities of the modifier functional groups. Ammonium salt derivatives supported on silica gel were prepared from silica modified with 3-Aminopropyltriethoxysiliane and N-3-(Trimethoxysilyl)propylehtylene diamine. The preparation and the ion exchange properties of two systems were discussed. Two systems have different hydrophilicities and contain ammonium chloride derivatives of 3-amminopropyltriethoxysilane and N-3-(triehtoxysilyl)propyl ethylene diamine supported on silica gel, SA+/Cl- and SA+/Cl-, respectively. The high affinity to perchlorate ion presented by the SA+/Cl- through the equilibrium studies of ion exchange led us to its application as an ion selective electrode for the perchlorate ion. The determination of the perchlorate ion in the presence of other anions and in complexes is very difficult. Few analytical methods are available and most of them are indirect. Both materials showed potential use as an ion exchanger; they are thermically stable, achieve equilibrium rapidly in the presence of suitable exchanger ions, and are easily recovered.

감응물질로 제4급 암모늄염을 사용하여 PVC를 지지체로 과염소산이온의 농도 10-6M까지 측정가능한 이온 선택성 전극을 제작하였다. 감응물질의 화학적 구조와 함량, 가소제의 종류 및 막 두께에 따른 선형응답 범위와 Nernst의 기울기 등 전극특성을 검토하여, 최적 막조건을 구한 다음 측정가능 pH범위와 여러 방해이온에 대한 선택계수를 비교 검토하였다. 과염소산 이온선택성 전극에서 감응물질의 화학적 구조 즉, 알킬기의 탄소고리수가 증가할수록 선형응답 범위 등 전극 특성은 Aliquat 336P, TOAP, TDAP 및 TDDAP의 순서로 좋아졌다. 가소제는 DBP가 가장 좋았고, 감응물질의 양은 최적 함량 이상에서 적을수록 좋았다. 최적 막 조성은 TDDAP 9.09, PVC 30.3 및 DBP 60.61wt%이었고, 막두께 0.45mm이었다. 이 조건에서 선형응답 범위 10-1~1.2 × 10-6M, 검출한계 5.1×10-7M 및 Nernst기울기 57mV/pClO4이었다. 막전위는 pH 4~11 범위에서 pH의 영향을 받지 않았으며, 선택계수 서열은 다음과 같았다. SCN->I->NO3->Br->ClO3->F->Cl->SO42-

As the concentration of ammonium nitrogen could be reached 2～3 mg/L in the winter in the river. It was clear that the excessive concentration of chlorinated organics could be produced with the increase of chlorine addition to remove ammonium nitrogen. In the innovative ammonium nitrogen removal process, zeolite adsorption is very efficient as substitute for rapid sand filtration without other adverse quality change in the water. This study is conducted to evaluate the feasibility of ammonium nitrogen removal and regeneration by zeolite adsorption in drinking water treatment. Also, the reuse possibility of zeolite is evaluated to change the removal efficiency of ammonium nitrogen through several times of regeneration. The ammonium nitrogen was not removed in sand filter, but it was almost removed in zeolite filter during 7 days. The sand and zeolite filters have a similar result of turbidity removal. Therefore, zeolite filtration was confirmed the removal of turbidity and ammonium nitrogen as a media. When compared KCl with NaCl as a chemical for zeolite regeneration, it is demonstrated that KCl was more efficient than NaCl in the ability of zeolite regeneration. The adsorption rate of ammonium nitrogen was almost not decreased in the results of several times of regeneration. It is indicated that both zeolite and regeneration solution were possible to reuse without variation of regeneration rate through this study.