The new life of traditional water treatment flocculant polyaluminum chloride (PAC): a green and efficient micro-nano reactor catalyst in alcohol solvents

Enhanced drilling waste-water treatment through magnetic nano-composite coagulant application: A central composite design study

A magnetic nano-composite coagulant has been designed, originally applied in a specific industrial waste-water treatment, and statistically investigated using Central Composite Design (CCD). The generated polynomial models were utilized to achieve a comprehensive understanding of the impact of each ingredient of PolyAluminum Chloride (PAC), PolyAcrylAmide (PAM), and Iron (III) oxide magnetic nano particles (MNP) regarding optimum limits and conditions. The concentration of each of those components has been considered as the main effective factors, which are found to be significantly correlated, affecting the Total Dissolved Solid (TDS) removal (%), the Total Suspended Solid (TSS) removal (%), and the Turbidity Reduction Rate (TRR) NTU/min. The reliable statistical model for each response underscored the pivotal role of MNP in shaping each response variable. The influence of MNP and PAC, emerged as crucial in enhancing TDS removal, by increasing the kinetic energy of charged ions and the chance of the successful displacement reaction, helping to dissolve with a high surface activity, and the adsorption of magnetic heavy ions. The correlated concentration of MNP also exhibited a significant impact on TSS elimination, and TRR, concurrently, which revealed the importance of controlling the bulk density of generated flocs, to prevent premature and immature settling to optimize pollution removal. The highest recorded results are 72.00 %, 77.01 %, and 23.82 NTU per minute for TDS and TSS removal and TRR, respectively. The experimental records, along with the statistical investigation remarked a promising potential of the achieved Magnetic Nano-composite Coagulant (MNC), and generated practical knowledge of its novel application for drilling waste-water management.

High-Efficiency Alkyl Ketene Dimer Emulsions Stabilized by Polyaluminum Chloride and Chitosan Complex

Based on the interaction of polyaluminum chloride (PAC) and chitosan (CTS) at the molecular level, an organic/inorganic composite material was designed for the preparation of alkyl ketene dimer (AKD) emulsion. This paper aimed to explore the influence of PAC/CTS on the physicochemical properties, microstructure, and sizing efficiency of AKD emulsions. The PAC/CTS complex forms a denser adsorption layer at the oil-water interface at the microscopic level. With the increase in CTS concentration, the AKD emulsions displayed excellent stability after high-speed centrifugation. In addition, the addition of CTS can effectively improve the sizing efficiency of the emulsion. Therefore, this study proposed a strategy of PAC/CTS as an emulsifier, and the related interaction mechanism was explored, which further expands the application of inorganic/organic composites in the field of colloidal chemistry.

Enhanced nutrient control efficiency in sediments using modified clay inactivation coupled with aquatic vegetation in the confluence area of a eutrophic lake

Developing a long-term method for controlling sediment N and P release is important for enabling lake restoration. In this study, inactivation methods using lanthanum-modified clay, modified zeolite, or planting aquatic vegetation and their combinations were used in the control internal sediment loading (pore water N and P concentrations and their fluxes), and the efficacies of the methods were analyzed. The results indicated that compared to the control sediment, the addition of P sorbent, which was La and Al co-modified attapulgite (ACLA), and N sorbent, which was NaCl-modified zeolite (modified zeolite), planting of aquatic vegetation Vallisneria spiralis (V. spiralis), and a combination of sorbents and plants effectively reduced the porewater nutrient content and its fluxes across the sediment-water interface. However, the reduction in pore water nutrients and flux were superior when using a combination of clay inactivation and aquatic planting. The poorest sediment N and P control was achieved by planting V. spiralis alone. The addition of La and Al co-modified attapulgite (ACLA) and modified zeolite efficiently reduced N and P in the sediment, but the N and P sorbents did not achieve long-lasting nutrient release control. The high efficiency obtained by the combination of modified clay-based inactivation and V. spiralis was likely due to the strong chemical sorption capacity of clay and oxygenation by the rhizosphere of aquatic vegetation. These results show that a combination of chemical and ecological methods would be the most effective approach to remediate polluted sediments in the long term.

Exploring the In Situ Formation Mechanism of Polymeric Aluminum Chloride-Silica Gel Composites under Mechanical Grinding Conditions: As a High-Performance Nanocatalyst for the Synthesis of Xanthene and Pyrimidinone Compounds

The use of mechanical ball milling to facilitate the synthesis of organic compounds has attracted intense interest from organic chemists. Herein, we report a new process for the preparation of xanthene and pyrimidinone compounds by a one-pot method using polymeric aluminum chloride (PAC), silica gel, and reaction raw materials under mechanical grinding conditions. During the grinding process, polymeric aluminum chloride and silica gel were reconstituted in situ to obtain a new composite catalyst (PAC-silica gel). This catalyst has good stability (six cycles) and wide applicability (22 substrates). The Al-O-Si active center formed by in situ grinding recombination was revealed to be the key to the effective catalytic performance of the PAC-silica gel composites by the comprehensive analysis of the catalytic materials before and after use. In addition, the mechanism of action of the catalyst was verified using density functional theory, and the synthetic pathway of the xanthene compound was reasonably speculated with the experimental data. Mechanical ball milling serves two purposes in this process: not only to induce the self-assembly of silica and PAC into new composites but also to act as a driving force for the catalytic reaction to take place. From a practical point of view, this "one-pot" catalytic method eliminates the need for a complex preparation process for catalytic materials. This is a successful example of the application of mechanochemistry in materials and organic synthesis, offering unlimited possibilities for the application of inorganic polymer materials in green synthesis and catalysis promoted by mechanochemistry.

In situ preparation of a ferric polymeric aluminum chloride–silica gel nanocatalyst by mechanical grinding and its solid-phase catalytic behavior in organic synthesis

PLASC catalysts have significant green chemistry properties and can be used as new cheap, efficient and green catalysts.