A New Mechanism of the Selective Photodegradation of Antibiotics in the Catalytic System Containing TiO2 and the Inorganic Cations

The mechanism of sulfisoxazole (SFF) selective removal by photocatalysis in the presence of titanium (IV) oxide (TiO2) and iron (III) chloride (FeCl3) was explained and the kinetics and degradation pathways of SFF and other antibiotics were compared. The effects of selected inorganic ions, oxygen conditions, pH, sorption processes and formation of coordination compounds on the photocatalytic process in the presence of TiO2 were also determined. The Fe3+ compounds added to the irradiated sulfonamide (SN) solution underwent surface sorption on TiO2 particles and act as acceptors of excited electrons. Most likely, the SFF degradation is also intensified by organic radicals or cation organic radicals. These radicals can be initially generated by reaction with electron holes, hydroxyl radicals and as a result of electron transfer mediated by iron ions and then participate in propagation processes. The high sensitivity of SFF to decomposition caused by organic radicals is associated with the steric effect and the high bond polarity of the amide substituent.

Wastewater Treatment for Heavy Metals and Dyes Using Low-Cost Biosorbents: A Review

The pollution of industrial wastewater with heavy metals and dyes is a highly important environmental problem, because of the propagation of the pollution and because of its unfavourable consequences. Sustainable wastewater treatment is one of the foremost challenges of this century. Various waste materials characterized by lignocellulose composition are low cost, non-conventional adsorbent for biosorptive removal of heavy metal ions from aqueous solutions. Recent studies point to the potential of use of low-cost materials (zeolites, carrot residue and green tea waste) as effective sorbents for the removal of Cd2+ from aqueous solution. The use of bentonite to the treatment of wastewater containing reactive dyes in aqueous solutions requires the modification of the hydrophilic surface by inorganic cations with organic cations exchange. The use of bentonite as an inexpensive sorbent for the removal of Remazol Brilliant Blue R (RBBR) from synthetic aqueous solutions has been also presented in recent studies. The influence of some parameters such as: pH, initial dye concentration, sorbent dose on sorption kinetics for dye removal has been reviewed in this paper.

Single- or double A-site cations in A3Bi2I9 bismuth perovskites: What is the suitable choice?

Investigations on the effect of single or double A-site cation engineering on the photovoltaic performance of bismuth perovskite-inspired materials (A3Bi2I9) are rare. Herein, we report novel single- and double-cation based bismuth perovskite-inspired materials developed by (1) completely replacing CH3NH3+ (methylammonium, MA+) in MA3Bi2I9 with various organic cations such as CH(NH2)2+ (formamidinium, FA+), (CH3)2NH2+ (dimethylammonium, DMA+), C(NH2)3+ (guanidinium, GA+) and inorganic cations such as cesium (Cs+), rubidium (Rb+), potassium (K+), sodium (Na+) and lithium (Li+) and (2) partially replacing MA+ with Cs+ in different stoichiometric ratios. Compared to single-cation based bismuth perovskite devices, the double-cation bismuth perovskite device showed an increment in the device power conversion efficiency (PCE) up to 1.5% crediting to the reduction in the bandgap. This is the first study demonstrating double-cation based bismuth perovskite showing bandgap reduction and increment in device efficiency and opens up the possibilities towards compositional engineering for improved device performance. Graphic Abstract

Stabilisasi Tanah Gambut Menggunakan Abu Boiler Kelapa Sawit Ditinjau Dari Nilai Cbr Laboratorium

Palm ash is the waste from the palm ash combustion which contains a lot of silicate. In addition, palm ash also contains inorganic cations such as potassium and sodium. Palm ash is pozzolanic material, which is a non-binding material such as cement, but contains active Silica Oxide (SiO2) compounds which when reacted with free lime or calcium hydroxide (Ca (OH2)) and water will form materials such as cement, namely calcium Silica Hydrate. In this study we will use palm ash waste which has been stated to have good soil improvement results as a mixture of peat soil improvement in the hope of getting better improvement results from previous studies in terms of California Bearing Ratio values. The boiler ash to be used is a variation of the mixture of 0%, 5%, 10% and 15% to the weight of the soil sample and using 28 days treatment. The California Bearing Ratio value of the original peat soil is 0.247%, the percentage of 5% increases to 0.433%, at the percentage of 10% is 0.629% and at the percentage of 15% is 0,729%.

Antioxidant Network Based on Sulfonated Polyhydroxyalkanoate and Tannic Acid Derivative

A novel generation of gels based on medium chain length poly(3-hydroxyalkanoate)s, mcl-PHAs, were developed by using ionic interactions. First, water soluble mcl-PHAs containing sulfonate groups were obtained by thiol-ene reaction in the presence of sodium-3-mercapto-1-ethanesulfonate. Anionic PHAs were physically crosslinked by divalent inorganic cations Ca2+, Ba2+, Mg2+ or by ammonium derivatives of gallic acid GA-N(CH3)3+ or tannic acid TA-N(CH3)3+. The ammonium derivatives were designed through the chemical modification of gallic acid GA or tannic acid TA with glycidyl trimethyl ammonium chloride (GTMA). The results clearly demonstrated that the formation of the networks depends on the nature of the cations. A low viscoelastic network having an elastic around 40 Pa is formed in the presence of Ca2+. Although the gel formation is not possible in the presence of GA-N(CH3)3+, the mechanical properties increased in the presence of TA-N(CH3)3+ with an elastic modulus G’ around 4200 Pa. The PHOSO3−/TA-N(CH3)3+ gels having antioxidant activity, due to the presence of tannic acid, remained stable for at least 5 months. Thus, the stability of these novel networks based on PHA encourage their use in the development of active biomaterials.

Role of NOM-Hematite Nanoparticle Complexes and Organic and Inorganic Cations in the Coherence of Silica and Clay Particles: Evaluation based on Nanoscale Forces and Molecular Self-assembly

The evaluation of the nanoscale forces between a silica probe and hematite nanoparticles (NPs) thin layer-coated mica (Hm-mica) in the presence of structurally different natural organic matter (NOM) and...