Utilization of Dredged River Sediment in Preparing Autoclaved Aerated Concrete Blocks

In this study,the dredged river sediment,soft texture and fine particles,is mixed with other materials and transformed into eco-friendly autoclaved aerated concrete(hereinafter referred to as AAC)blocks.The results indicated the bricks produced under the conditions of 30%–34%dredged river sediment,24%cement,10%quick lime,30%fly ash,2%gypsum and 0.09%aluminum powder with 0.5 water to material ratio,2.2 MPa autoclave pressure and 6 h autoclave time,the average compressive strength of 4.5 MPa and average dry density of 716.56 kg/m³were obtained,the two parameters(strength&density)both met the requirement of national industry standard.At the same time,the contents of dredged river sediment,cement,lime,fly ash,gypsum and aluminum powder were 15%,48%,20%,15%,2%and 0.09%,respectively,and the non-AAC block made of 0.5 water to material ratio,the average compressive strength of 3.1 MPa and average dry density of 924.19 kg/m³were obtained,the two parameters(strength&density)also met the requirement of national industry standard.In addition,the AAC block’s phase composition and morphology were micro-analyzed by SEM and XRD,the main substances in AAC block were found to be tobermorite and CSH,Among them,the chemical bond between Si-O-Si and Al-O-Al is broken,Al-O-Si is regenerated,Al substituted tobermorite with better strength is formed,and the compressive strength of AAC is further improved.

Rational Design of a High-Performance KMnO_(4)-Fe(Ⅱ)-Si Coagulant for Dye Removal

A new ternary coagulant polysilicate ferromanganese(PSFM),composed of Fe,Mn and Si,was designed.Its coagulation performance for dye removal was investigated systematically together with the impact of several key operational parameters.The experimental results indicate that an excellent coagulation efficiency with higher than 95%color removal and higher than 94%total organic carbon(TOC)removal can be obtained at an optimized molar ratio of Si∶Fe∶Mn(5∶5∶1).The coagulation performance of PSFM coagulant was studied comparatively with other conventional coagulants,e.g.poly aluminium chloride(PAC),Al_(2)(SO_(4))_(3)and FeCl_(3).Additionally,various characterization techniques were applied to get detailed morphological and compositional information of PSFM coagulants.Furthermore,the underlying mechanism for improved coagulant performance was proposed based on these results.These results have exemplified quantitatively that PSFM coagulant exhibits a great potential as a promising material for application in various environmental fields.

Assessment of VIIRS 375 m active fire using tropical peatland combustion algorithm applied to Landsat-8 over Indonesia’s peatlands

VIIRS 375 m active fire data(VNP14IMG),the highest spatial resolution available cost-free fire product,were assessed for representing fire in typical degraded tropical peatlands in Indonesia.The results of applying the Tropical Peatland Combustion Algorithm to Landsat-8(ToPeCAl-L8)daytime imagery were utilised as the fire references.To permit the comparison of non-simultaneous VNP14IMG and ToPeCAl-L8,peatland fire propagation speeds resulting from previous study using TET-1 data in Central Kalimantan’s peatlands were utilised.Most peatland fires were still within 750 m from their source over 15 h under uniform conditions,except for very large fires.The detection rates of nighttime VNP14IMG compared with ToPeCAl-L8 showed about 80%agreement for small fire areas(<14 ha).For fires larger than 14 ha,a dissolved 375 m buffer(cluster buffer)of VNP14IMG active fires with an integration of nighttime and daytime acquisitions,produced a probability of detection up to 90%.These results generated a recommendation for implementing cluster buffer analysis and integration of nighttime and daytime analysis of VNP14IMG data for better accuracy in fire detection for ground fire management.They also demonstrate the utility of the ToPeCAl-L8 algorithm with VIIRS 375 m active fire data.