Studies on the removal of phenol from aqueous solutions by adsorption on sewage treatment plant biosolids (BS) as low-cost adsorbent were carried out with an aim to obtain information on treating phenol-containing wastewater from different industries. A series of experiments were undertaken in a batch adsorption technique to access the effect of the process variables i.e. initial phenol concentration, contact time, initial pH and adsorbent dose. The results showed that the adsorption capacity of BS in aqueous solution increased with the decrease in initial concentration and pH, and increase in contact time and dose of adsorbent. The experimental results were fitted by Langmuir and Freundlich isotherms to describe the biosorption processes.
Adsorption ; Phenol/*pharmacokinetics ; Plant Components ; *Sewage ; Thailand ; Waste Disposal, Fluid/*methods ; Water Pollutants, Chemical/*pharmacokinetics

OBJECTIVEThis study was to assess the influence of interaction of combination of immobilized nitrogen cycling bacteria (INCB) with aquatic macrophytes on nitrogen removal from the eutrophic waterbody, and to get insight into different mechanisms involved in nitrogen removal.

METHODSThe aquatic macrophytes used include Eichhornia crassipes (summer-autumn floating macrophyte), Elodea nuttallii (winter-growing submerged macrophyte), and nitrogen cycling bacteria including ammonifying, nitrosating, nitrifying and denitrifying bacteria isolated from Taihu Lake. The immobilization carriers materials were made from hydrophilic monomers 2-hydroxyethyl acrylate (HEA) and hydrophobic 2-hydroxyethyl methylacrylate (HEMA). Two experiments were conducted to evaluate the roles of macrophytes combined with INCB on nitrogen removal from eutrophic water during different seasons.

RESULTSEichhornia crassipes and Elodea nuttallii had different potentials in purification of eutrophic water. Floating macrophyte+bacteria (INCB) performed best in improving water quality (during the first experiment) and decreased total nitrogen (TN) by 70.2%, nitrite and ammonium by 92.2% and 50.9%, respectively, during the experimental period, when water transparency increased from 0.5 m to 1.8 m. When INCB was inoculated into the floating macrophyte system, the populations of nitrosating, nitrifying, and denitrifying bacteria increased by 1 to 2 orders of magnitude compared to the un-inoculated treatments, but ammonifying bacteria showed no obvious difference between different treatments. Lower values of chlorophyll a, COD(Mn), and pH were found in the microbial-plant integrated system, as compared to the control. Highest reduction in N was noted during the treatment with submerged macrophyte+INCB, being 26.1% for TN, 85.2% for nitrite, and 85.2% for ammonium at the end of 2nd experiment. And in the treatment, the populations of ammonifying, nitrosating, nitrifying, and denitrifying bacteria increased by 1 to 3 orders of magnitude, as compared to the un-inoculated treatments. Similar to the first experiment, higher water transparency and lower values of chlorophyll a, COD(Mn) and pH were observed in the plant+ INCB integrated system, as compared to other treatments. These results indicated that plant-microbe interaction showed beneficial effects on N removal from the eutrophic waterbody.

Biodegradation, Environmental ; Eutrophication ; physiology ; Magnoliopsida ; metabolism ; Nitrogen ; isolation & purification ; pharmacokinetics ; Systems Integration ; Water Microbiology ; Water Pollutants, Chemical ; isolation & purification ; pharmacokinetics ; Water Purification ; methods

This study examines the possibility of using live spirulina to biologically remove aqueous lead of low concentration (below 50 mg/L) from wastewater. The spirulina cells were first immersed for seven days in five wastewater samples containing lead of different concentrations, and the growth rate was determined by light at wavelength of 560 nm. The 72 h-EC50 (72 h medium effective concentration) was estimated to be 11.46 mg/L (lead). Afterwards, the lead adsorption by live spirulina cells was conducted. It was observed that at the initial stage (0-12 min) the adsorption rate was so rapid that 74% of the metal was biologically adsorbed. The maximum biosorption capacity of live spirulina was estimated to be 0.62 mg lead per 10(5) alga cells.
Bacterial Proteins ; drug effects ; metabolism ; physiology ; Biodegradation, Environmental ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Feasibility Studies ; Lead ; administration & dosage ; isolation & purification ; pharmacokinetics ; Metabolic Clearance Rate ; Spirulina ; Water Pollutants, Chemical ; administration & dosage ; pharmacokinetics ; Water Purification ; methods