Enhanced remediation efficiency of Cr(VI)-contaminated heterogeneous aquifers: Improved sweeping efficiency using shear-thinning fluids.

Low permeability zones (LPZs) are typically bypassed when remedial reagents are injected into heterogeneous aquifers, which hinders the in situ remediation. Although shear-thinning polymers have emerged as promising tools to meet this challenge, their applicability in complex remedial systems remains unconfirmed. We investigated the sweeping efficiencies of calcium polysulfide (CPS) into Cr(VI)-contaminated LPZs using xanthan gum (XG) as the model shear-thinning polymer.

An integrated process for the advanced treatment of hypersaline petrochemical wastewater: A pilot study.

An integrated process combining ozonation, ceramic membrane filtration with biological activated carbon filtration (O+CMF + BAC process) was designed and evaluated using a pilot scale (10 m/d) test for the advanced treatment of hypersaline petrochemical wastewater in a coastal wastewater plant. The membrane flux and ozone dosage were optimized for the optimal treatment performance of this integrated process. The results showed that this integrated process performed well in pollutant removal.

Modification on the conventional procedure to measure AOC in drinking water.

Additional phosphorus will be introduced to water sample if the conventional procedure is used to measure assimilable organic carbon (AOC) in drinking water. It has been shown that there are the cases that phosphorus is the limiting nutrient for microbial growth in drinking water. The measured value of AOC would not be able to indicate appropriately the regrowth potential of bacteria in this case.

[Comparison on the performance of biostyr and bio-ceramic filter used for biological pretreatment of raw water].

A new biological filter called biostyr using biostyrene as media to purify raw water was compared with the widely studied bio-ceramic filter. The raw water was taken from a reservoir located in Northern China. It was shown this new biological filter could obviously improve the raw water quality.

Phosphorus limitation on bacterial regrowth in drinking water.

Assimilable organic carbon (AOC) test and bacterial regrowth potential (BRP) analysis were used to investigate the effect of phosphorus on bacterial regrowth in the drinking water that was made from some raw water taken from a reservoir located in northern China. It was shown that AOC of the drinking water samples increased by 43.9%-59.

[Improvement of biological pretreatment performance by addition of phosphorus].

Addition of phosphorus as a novel way to improve the performance of bio-ceramic filter for biological pretreatment of source water was conducted. More bacteria grown in raw water and the BDOC of raw water increased when 50 micrograms/L PO4(3-)-P (NaH2PO4) was added alone were clear evidence of phosphorus limitation on bacterial growth. It shown that about 4.

Improvement of organics removal by bio-ceramic filtration of raw water with addition of phosphorus.

The purpose of this study was to investigate the effect of phosphorus addition on biological pretreatment of raw water. Experiments were conducted in pilot-scale bio-ceramic filters with raw water from a reservoir located in Beijing, China. The results demonstrated that phosphorus was the limiting nutrient for bacterial growth in the raw water investigated in this study.

[Relation between phosphorus and bacterial regrowth in drinking water].

In the experiment, a bioassay called Bacterial Regrowth Potential (BRP) was used to investigate the effect of phosphorus on bacterial regrowth in the water sample that was made from some raw water taken from a reservoir located in northern China. It was shown that BRP of water sample increased about 100%-235% when 50 micrograms/L PO4(3-) -P (as NaH2PO4) was added alone. BRP of water sample with various inorganic nutrients (including phosphate) addition had the similar increase compared with BRP of water sample with only 50 micrograms/L PO4(3-) -P addition and BRP of water sample with acetate-C of 1 mg/L addition increased only 30%-40%.

[Performance of bio-ceramic reactor at low temperature].

A bio-ceramic reactor for slightly polluted source water from Guanting Reservoir in Beijing was conducted at low temperature. It was shown that the removal rate of CODMn and NH4(+)-N decreased from 20% to 6%, 90% to 65% respectively when the temperature fell from 10 degrees C to 0.5 degree C.