Porous Haydite Used as Waste Water Filter Medium for Lake Sludge

Porous haydite used as waste filter medium was prepared by dreging lake sludge to help solve the treatment problem of sludge and realize its reclamation. Several calcination regimes were considered and their effects on the pore structure and the properties such as the strength, the density, the filtering ability and the phosphate absorption ability of the haydite were investigated, For the mixture of 60% lake sludge and 40% fly ash in this experiment, the calcination regime with a pre-caleination period at about 600℃, a temperature keeping period at 1 200 ℃ and a moderate cooling rate are recommended to prepare haydite with reasonable pore structure and good performances for its usage as the waste water filter media.

Oily Wastewater Treatment by Porous Ceramics Mediums with Surface Lipophilic Modification

Aiming at the treatment of difficult-to-handle oily wastewater, the ceramics filter mediums made from the iron and steel plant sludge were adopted to surface lipophilic modification so as to remove oil efficiently. The hydrolysis technique by FTIR and conductivity test indicated that under acid conditions hydrogen silicon oil did not hydrolyze but release hydrogen by chemical reaction under alkaline conditions. The results of the experiments including contact angle measurement, FTIR analysis, and SEM analysis illustrate that a layer of lipophile coating indeed exists evenly on the surface of filter mediums after modification. Furthermore, the hydrogen-containing silicone oil was combined through dehydration of Si-H bond with the-OH on the surface of ceramic filter medium.

Dynamic Adsorption of Microwave Modified Attapulgite on Micro-polluted Phenol Wastewater

[Objective] The paper was to study the dynamic adsorption of microwave modified attapulgite on micro-polluted phenol wastewater. [Method] Cetyl trimethyl ammonium bromide （CATB） modified attapulgite was used to modify attapulgite, and conducted dynamic test on micro-polluted phenol wastewater. The dynamic charac- teristics of phenol removal were also studied. [Result] Attapulgite modified by CATB has strong adsorption ability on phenol in micro-polluted water, the phenol removal rate increased with the decrease of flow rate of wastewater. When pH value was 6- 8, phenol concentration in wastewater was 17.74 mg/L, flow rate was 2 m/s and ad- sorption time was 25 rain, the removal rate reached 93.07%. The modified atta- pulgite could be regenerated with alkali, and its adsorption ability after regeneration had no obvious decline. The dynamic adsorption process of phenol accorded with the first-order kinetic equation. [Conclusion] The study provided basis for further study on ＂organic matter removal in wastewater.

Efficiency of locally available filter media on fluoride and phosphate removal for household water treatment system

Since conventional water treatment is not affordable in developing countries,looking for locally available and alternative treatment options is mandatory.Removal of fluoride and phosphate can be achieved by designing appropriate filtration media from different materials such as sand,calcined clay,pumice,scoria and bone char.This study was designed to determine the removal efficiency of these locally available filter media with respect to detention time and pH.The filtration apparatuses(tank) were filled separately with stone,gravel with grain size 0.6-4.75 mm and 40 cm deep,sand(ES = 0.15—0.35 mm and UC = 1.5-3),calcined clay,pumice,scoria and bone char with grain size 0.25-0.5 inch.Water samples were prepared using glass bottles with fluoride concentrations of 6 and 8 mg/1 and phosphate concentration of 4 mg/1.Laboratory analysis was carried out before and after filtration to determine the removal efficiency of each medium.It was found that the highest removal of fluoride was achieved by bone char(89.65%),followed by pumice(82.4%).However,bone char has rather increased the concentration of phosphate by 63.8%.Sand was the most efficient media to remove phosphate,managing to remove by 70%.Therefore,it is an attractive option to use these locally available,environmental friendly and appropriate technologies for efficient removal of both fluorine and phosphate at the household or community water treatment level.

Development and Application of TL-1 New High Temperature and High Pressure Plugging Instrument

In view of the fact that most of the filter media of existing plugging evaluation instruments use steel plates or steel balls, which cannot truly simulate the characteristics of the formation, a new type of TL-1 high temperature and high pressure plugging instrument has been developed. The filter medium of the instrument is the natural stone with different cracks and quartz sand beds with different particle sizes, which can better simulate the adsorption and hang-up effect of the formation on the plugging agent. It is possible to evaluate the plugging effect, pressure-bearing capacity and return pressure of the plugging slurry for different cracks and sand beds of different sizes under different temperatures and pressures. Using new and old instruments to evaluate the plugging effect of the same plugging slurry, it is found that the plugging effect is different from the distribution of the plugging material on the crack surface, the plugging effect and the pressure bearing capacity. The instrument is stable and reliable in operation and simple in operation. It is a new instrument for conducting research on anti-leakage plugging materials and anti-leakage plugging drilling fluid systems.

Characteristic research of regeneration process of particulate filter medium in vibrated fluidized bed

The vibrational fluidized bed is innovatively adopted to regenerate the particulate filter medium for the purification of crude syn-thesis gas from the coal gasification process.Characteristic research of vibrated fluidized beds during dust-containing particulate filter medium regeneration has been carried out.The ideal transport model of particulate filter medium on the distributor is estab-lished and verified by using experiments.The mean residence time of the particulate filter medium can be reduced by 72%from 5.5 to 1.5 min with an increase in the working frequency from 50 to 60 Hz.The thickness of the bed layer is linearly increased with the feeding rate of the particulate filter medium under ideal working conditions.The resistance models of the fluidizing air are built up and validated,and they can be used to calculate the pressure drop of the static bed layer of the particulate filter medium on the flu-idizing air distributor,which is the maximum value of the dynamic bed layer with the same thickness.The fluidizing air makes the mean residence time of the particulate filter medium decrease by 50%and reduces the difference in the particulate mean residence time under different feeding-rate conditions.The regeneration effect of dust-containing filter medium particles in a vibrated fluidized bed is evaluated.Fluidizing air with superficial velocity ranging from 0 to 0.6~0.9 m·s-1 makes the regeneration efficiency increase from 29.41%to 70.59~88.24%.This article provides a reference for the industrial application of a vibrated fluidized bed for the par-ticulate filter medium recycling system.

Integration of high-rate filtration using waste-derived biochar as a potential sustainable technology for drinking water supply

This research aimed to evaluate the efficiency of eucalyptus(E)and bamboo(B)residual biomass biochars as filter materials for drinking water treatment.The efficiencies of these two biochars in the rapid filtration process were evaluated using water(raw,flocculated and settled)at the rate of 120 m^(3)/m^(2)/d.Finding that bamboo biochar manufactured under a slow pyrolysis process"b"(Bb)had the best performance.Subsequently,Bb was evaluated with three different granulometries,and it was found that the effective size with the best performance was the finest(0.6-1.18 mm).Subsequently,this biochar was compared with conventional filter materials such as gravel,sand and anthracite,using different types of water(raw,flocculated and settled)and at different filtration rates(120 and 240 m^(3)/m^(2)/d),and it was found that the filter material with the best performance was precisely biochar,with average removal efficiencies of 64.37%turbidity and 45.08%colour for raw water;93.9%turbidity and 90.75%colour for flocculated water,and 80.79%turbidity and 69.03%colour for settled water.The efficiency using simple beds of sand,biochar,anthracite and gravel at the rate of 180 m^(3)/m^(2)/d was 75.9%copper,90.72%aluminium,95.7%iron,10.9%nitrates,94.3%total coliforms and 88.9%fecal coliforms.The efficiencies achieved by biochar were higher compared to those of conventional filter materials.It was also found that biochar contributes to improving the performance of sand and anthracite in mixed beds.Additionally,it was possible to demonstrate that the volume of washing water required for the biochar is lower compared to the other filter beds.Finally,it is recommended to carry out more tests for the purification of water with biochars from rural areas affected by the mining and oil exploitation,as well as the purification of seawater with biochars from coastal areas with residues from dry forests and organic residues from municipalities.