Oxocarbon salts (M2(CO)n) prepared through one-pot proton exchange reactions with different metal ions (M=Li, Na, K) and frameworks (n=4, 5, 6) have been rationally designed and used as electrodes in rechargeable Li, Na, and K-ion batteries. The results show that M2(CO)5/M2(CO)6 salts can insert two or four metal ions reversibly, while M2(CO)4 shows less electrochemical activity. Especially, we discover that the K2C6O6 electrode enables ultrafast potassium-ion insertion/extraction with 212 mA h g−1 at 0.2 C and 164 mA h g−1 at 10 C. This behavior can be ascribed to the natural semiconductor property of K2C6O6 with a narrow band gap close to 0.9 eV, the high ionic conductivity of the K-ion electrolyte, and the facilitated K-ion diffusion process. Moreover, a first example of a K-ion battery with a rocking-chair reaction mechanism of K2C6O6 as cathode and K4C6O6 as anode is introduced, displaying an operation voltage of 1.1 V and an energy density of 35 Wh kg−1. This work provides an interesting strategy for constructing rapid K-ion batteries with renewable and abundant potassium materials.
The Lighter Side of Geomembranes
Geomembrane installations often cover substantial areas. Landfill cells pose enormous footprints. Oil and gas pits, industrial processing ponds, and wastewater containment ponds are large installations too, and each year they tend to be built a little larger. The scaling up of these facilities is not just a matter of achieving better operational economics for the facility owner; it’s also because geosynthetic materials perform well and strong installation practices continue to prove that another leap in...
A High-Performance Base-Metal Approach for the Oxidative Esterification of 5-Hydroxymethylfurfural
Exploring high-performance base-metal approaches for the sustainable production of chemicals from biomass is presently attracting immense interest and is truly important to promote their industrialized application. Herein, CoOx-N/C and α-MnO2 were combined as a base-metal catalyst that can achieve high yields of furan-2,5-dimethylcarboxylate (FDMC, 95.6 %) for the catalytic oxidative esterification of 5-hydroxymethylfurfural (HMF) without basic additive. The reaction proceeds through fast conversion...
How & Why We Measure Suspended Solids
In case you weren’t sure, Suspended Solids is simply a density measurement used to describe exactly how much waste sludge and particles are in the water, and is measured in milligrams per litre (mg/l), grams per litre (g/l) or percentage solid (%). 1000mg/l = 1g/l = 0.1%.It is used to calculate the amount of material, or load, in a wastewater or industrial system. Suspended Solids can be made up of both organic material (such as algae and plankton) and inorganic material (such as silt and sand) depending...
Polishing of treated palm oil mill effluent (POME) from ponding system by electrocoagulation process
As the ponding system used to treat palm oil mill effluent (POME) frequently fails to satisfy the discharge standard in Malaysia, the present study aimed to resolve this problem using an optimized electrocoagulation process. Thus, a central composite design (CCD) module in response surface methodology was employed to optimize the interactions of process variables, namely current density, contact time and initial pH targeted on maximum removal of chemical oxygen demand (COD), colour and turbidity with satisfactory...
Paste thickener bed level measurement
Numerous studies and papers have been devoted to the subject of thickener design and operation to achieve specified throughput and discharge densities. Mathematical models have been developed that present methods for sizing thickeners and predicting performance under varying process conditions. The compression effect of deeper beds on dewatering performance is a recognized phenomenon. This is one variable of many that are inter-related and influence thickener performance. For example in the steady-state, continuous...