Clean-soil Air Water最新文献

The interactions of six typical antibiotics, including azithromycin, clarithromycin (CLR), ciprofloxacin, sulfathiazole, sulfamethoxazole, and tetracycline (TCY), with Microcystis aeruginosa were investigated, discussing the effects of antibiotics on algal growth in terms of mono- and co-antibiotics, and the removal of six antibiotics by the alga. The results showed that all the antibiotics showed “low-promoting and high-inhibiting” effects, except for sulfonamides, which showed a promotion trend on algal cell density and chlorophyll a. The tests of half effective concentrations (EC₅₀s) of antibiotics against M. aeruginosa showed that the antibiotics of the same category had similar EC₅₀s, and the toxicity effects of co-antibiotics were higher compared to mono-antibiotics. The toxic effects of antibiotics against M. aeruginosa were antagonistic in most binary co-antibiotics, and synergistic and simple additive effects in the ternary co-antibiotics. For removal tests of antibiotics by the alga, it could be seen that at the same concentration (10 µg L⁻¹), M. aeruginosa showed the best removal of TCY with 22.8% and the lowest removal of CLR with only 5.8%. It was found that both antibiotics and M. aeruginosa had mutual influences; therefore, the interaction might be favorable to the permanent removal of antibiotics and reduce the impact on the aquatic ecological environment.

As solid waste of coal-fired power plants, atmospheric environmental pollution is caused by fly ash during transportation. The purpose of this study was to improve the dust removal efficiency of fly ash fine particles by electrocoagulation and obtain reasonable operating parameters. The effects of particle concentration, gas velocity, AC frequency, and voltage on particle electrocoagulation efficiency were studied through the establishment of a discrete element soft sphere calculation model, and reasonable electrocoagulation operation parameters were obtained. The dust removal process was evaluated according to the particle number concentration, electrocoagulation efficiency, and particles microscopic characteristics due to the dust removal experiments of fly ash by electrocoagulation. The results demonstrated that increasing particle concentration, reducing gas velocity, and selecting reasonable AC frequency and voltage were effective to improve the real-time electrocoagulation efficiency and its stability. Under the suitable conditions: voltage of 3 kV, airflow velocity of 5 m s^–1, particle concentration of 30 mg m^–3 and AC frequency of 100 Hz, the electrocoagulation efficiency was higher than 40%. The electrocoagulation was effective to improve the dust removal efficiency of fly ash fine particles with a relative humidity of air below 70% and ambient temperatures above 20°C.

The use of Internet of Things (IoT) in industries is not new; however, the amalgamation of IoT and Biotechnology is still less explored. IoT in wastewater treatment comes with a full suite including cloud and its corresponding ecosystem. The available cloud-based systems are advantageous, but costly and tightly coupled to their own cloud infrastructure. Opportunities are limited for the creation of a hybrid/multiple cloud model as it's difficult to integrate with the legacy system(s) and/or customized systems. The current investigation focuses on designing architechture of an open source IoT platform on an effluent treatment plant (ETP) protoype of textile industry. The designed prototype includes physical (adsorption) and biological (Rotating Biological Contactor, RBC, immobilized with white rot fungus) processes. IoT has been used for automated data monitoring of pH and ultrasound (for effluent flow from one tank to another, with respect to the water level, for processing). The process operated under an optimized pH (6.53±0.15) with reduction of representative wastewater quality parameters, biological & chemical oxygen demand, total dissolved solids, total suspended solids and optical density by 78.9, 52.15, 91.6, 20.3 and 88.8%, respectively. The findings demonstrated the reliability of the designed system and the analytics on treatment facilities.

Soil remediation with minimum amendments is a good strategy for tailings disposal. Carbonate-rich gold-copper mine tailings occurring alongside the Yangzi River, China, were employed as the objective in this study. They showed the characteristics of fine particles and alkaline pH with high density and low nutrition. The amendments including bacterial fertilizer (BF), polymer, peat, straw, and compound fertilizer (CF) were used for soilless remediation on the tailings. Soil quality index (SQI) involved in tailing properties and growth characteristics of ryegrass was used to optimize the combination of amendments. The results showed that the optimum amendment combination was 0.2% BF + 0.6% CF + 0.2% polymer + 10% peat and 2% straw. Tailing nutrients such as soil organic matter (5.56%), available nitrogen (93.6 mg kg⁻¹), available phosphorus (51.7 mg kg⁻¹), available potassium (711 mg kg⁻¹), and ryegrass exhibited the highest germination rate and biomass level under the optimal improvement conditions. Additional environmental assessments revealed that soilless treatment of the tailings helped to convert Cu, Zn, and As into residual forms. These findings show a good strategy for tailings soil improvement and provide a promising perspective of the soilless remediation for fine carbonate-rich metal tailings.

In this study, an anion exchange material obtained by chemically modifying granulated polyvinyl chloride with urea was examined. To study the structural morphology of the anion exchanger, polymer PVC-based anion exchange resin second type (PPE-2), we applied different characterization techniques including X-ray diffraction (XRD), Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), and water vapor adsorption analysis. Moreover, PPE-2 was used to remove hexavalent chromium ions from aqueous media. A pseudo-second order model was used to describe sorption kinetics as well as the adsorption mechanism. The Langmuir isotherm and the pseudo-second order kinetic model led to the most consistent results in describing ion removal from solution. In the case of hexavalent chromium ions, the maximum adsorption capacity was 148.4 mg g⁻¹. The Dubinin-Radushkevich (D-R) free energy of adsorption (E_D) was >16 kJ mol⁻¹, which indicates chemical interaction between the ion exchange material and Cr(VI) ions. The Gibbs energy ΔG, enthalpy ΔH, and entropy ΔS changes during binding showed that the sorption process is spontaneous and involves chemical sorption through endothermic ion exchange reactions. In addition, the results demonstrate that the anion exchanger (PPE-2) very efficiently removed hexavalent chromium ions from industrial wastewater.

The cover image is based on the Research Article Nitrate removal from groundwater by microscale zero-valent iron and activated carbon: A nonpumping reactive wells experiment by Seiyed Mossa Hosseini et al., https://doi.org/10.1002/clen.202300019

The disposal of solid waste in dumpsites is getting increased in developing countries due to rapid urbanization. Biomining is an innovative idea to recover valuable resources from legacy waste and usable land from old dumpsites. Various mechanical equipments are employed in the biomining process, out of which the trommel screen plays a major role in sieving the legacy waste into different fractions. Optimization of trommel screen performance in the biomining process is carried out in this project. Feasible operating parameters such as the feed rate of the trommel screen 1 (100 mm) and trommel screen 2 (4 mm) and moisture content of legacy waste were optimized in the Rajapalayam biomining site, Tamil Nadu, India. The characteristics of legacy waste in three different biomining sites, namely, Rajapalayam, Srivilliputhur, and Sivakasi, were analyzed. Results indicate that 9 and 2 m³ h^–1 feed rates show more separation efficiency for trommel 1 and 2, respectively. Changing the feed rates to the optimized values is also suggested to get better separating efficiency without compromising the purity and recovery of fractions. The recovery of the underflow fraction is maximum at a moisture content of 1.5% and 5.3% for trommel 1 and trommel 2, respectively. The trommel screen gets clogged for higher and lower values of moisture content so that the recovery of the underflow fraction gets affected. The refuse-derived fuel (RDF) characteristics meet the standard for reuse in cement kilns, and the bioearth characteristics are not suitable to be used as a soil amendment in its original form due to the unavailability of nutrients such as NPK and elevated C/N ratio.