chlorophyll-a and 4-chlorophenol

Using different rations of sludge extracts and supernate from 4-Chlorophenol (4-CP) simulated wastewater's excess sludge after centrifugation to cultivate the Chlorella vulgaris to achieve the goal of excess sludge utilization together with chlorella cultivating. The experiments were performed in 500 mL flasks with different rations of sludge extracts & BG-11 and supernate & BG-11 in a light growth chamber respectively. Number of algal cells, Chlorophyll, enzyme activity, oil and water total nitrogen (TN), total phosphorus (TP), total organic carbon (TOC), toxicity index were investigated. Result showed that the nutrition supplies and toxicity in the excess sludge were removed efficiently via Chlorella vulgaris, the removal rates of TN and TP were at least 40% and 90% respectively; After 10 days cultivation, the density growth of 50% sludge extracts was 20 times higher of the beginning while its chlorophyll content was lower than that of the blank group. Sludge extracts could promote the proliferation of algae, but were not conducive to the synthesis of chlorophyll. The quantity of SOD in per cell showed Chlorella vulgaris gave a positive response via stimulation from toxicant in sludge extracts and supernate. The best time for collecting chlorella vulgaris was the fifth day of cultivation, taking neutral oil accumulation as the evaluating indicator for its utilization combined with the removal of supplies and toxicity.

Topics: Chlorella vulgaris; Chlorophenols; Chlorophyll; Nitrogen; Phosphorus; Sewage; Waste Disposal, Fluid; Wastewater; Water; Water Pollutants, Chemical

Toxicity of 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) on the growth of Chlorella vulgaris was investigated in batch reactors. Results revealed that 4-CP did not adversely affect the growth of algae up to 20mg/L, however higher concentrations inhibited growth appreciably and no growth was detected at 100mg/L. 4-CP also caused some physiological changes in the algal cells as increasing initial 4-CP concentration caused a linear decrease in chlorophyll a (chl-a) content of the cell. 2,4-DCP up to 20mg/L did not exert toxic effect on the growth of C. vulgaris, rather an induction effect was evident. Unlike a linear decrease with 4-CP, no exact correlation between 2,4-DCP concentration and chl-a content of the cell was observed, but it was certain that the presence of 2,4-DCP caused some physiological changes in the cell of C. vulgaris. No biodegradation of 4-CP and 2,4-DCP was observed over a 30-day incubation.

Topics: Anthelmintics; Anti-Infective Agents, Local; Chlorella vulgaris; Chlorophenols; Chlorophyll; Chlorophyll A; Dose-Response Relationship, Drug; Environmental Monitoring; Water Pollutants, Chemical

The fate and effects of 4-chlorophenol (4CP) and 2,4-dichlorophenol (DCP) added to North Sea coastal plankton communities enclosed by large plastic bags were studied in three experiments of 4 to 6 weeks duration. The biodegradation of the compounds was studied in laboratory experiments using water from the enclosed ecosystems. 4CP and DCP, added at initial concentrations of 0.1-1.0 mg X liter-1, disappeared from the water in the enclosures in 5 to 23 days, 4CP generally being the less persistent. Degradation rates were generally comparable to those found in laboratory tests with the same water. 4CP was removed by biodegradation, and DCP was probably removed by a combination of biodegradation, photodegradation, and/or chemical degradation. Results indicated that biodegradation rates could be limited by lack of inorganic nutrients, leading to much lower degradation rates than would be expected from routine laboratory tests. Faster degradation after repeated addition of 4CP showed adaption of the bacterial community. Addition of 0.3 mg liter-1 4CP or DCP inhibited the phytoplankton growth rate slightly. The 1 mg liter-1 4CP or DCP inhibited the phytoplankton, changed the species composition, and also influenced the zooplankton. In two of the three experiments 1 mg liter-1 DCP resulted in a temporary lowering of bacterial numbers following the addition. In one experiment inhibitory effects were found after 4CP and DCP had disappeared from the water, pointing to the formation of a more toxic intermediate during the degradation of these compounds. The laboratory tests also indicated the formation of relatively stable intermediates. The concentrations causing the effects in the different bag experiments were quite similar. This indicates that, although the development of the plankton communities during the different experiments was different, the concentrations resulting in ecological effects are quite reproducible.

Topics: Animals; Biodegradation, Environmental; Chlorophenols; Chlorophyll; Plankton; Water Pollutants; Water Pollutants, Chemical