Advanced Materials Research Vols. 518-523

Abstract: Anaerobic digestion process has been widely used for organic wastewater, and could produce biogas which would be one of important sustainable energy. The biogas always contains some toxic, corrosive and odor hydrogen sulfide, which must be removed before utilization. Bio-desulfurization is a novel method for the removal of hydrogen sulfide by sulfide oxidizing bacteria. This process contains hydrogen sulfide adsorption and sulfide oxidizing sections. Sulfide oxidizing section should be coupled with adsorption section. In this study, some important parameters of adsorption section were tested for the effect on the growth of sulfide oxidizing bacteria. How the sulfide oxidizing section efficiently coupled with adsorption section was discussed. Our results showed that the optimal adsorbent was 0.1 M NaHCO3/Na2CO3 buffer and pH 8.0. The content of S2- in the effluent of adsorption section was 20 mM. If countercurrent absorption process used, the bio-desulfurization process was suitable for the treatment of the biogas, whose content of hydrogen sulfide was above 15,000 ppm.

Abstract: Temperature was a very important factor affecting the efficiency of biological nitrogen and phosphorus removal, as temperature sharply affecting the biological activity of biomass. A pilot-scale anoxic-anaerobic oxidation ditch (OD) process was used to investigate the efficiency of organic, nitrogen and phosphorus removal under the low temperature condition in this study. The results indicated that the nitrification and COD removal was very sensitive to the temperature changing, but the TP removal was not sensitive. When the temperature decreased from 25 degrees Celsius to15 degrees Celsius, the water quality of the effluent deteriorated obviously. A high removal rate of COD, TN, NH4+-N and TP was achieved at temperature of 15 degrees Celsius by changing the operational parameters in this study. The average concentration of COD, TN, NH4+-N and TP in effluent was 26.2 mg/L, 12.1 mg/L, 3.9 mg/L and 0.34 mg/L respectively.

Abstract: Using the Hydrilla verticillata - water hyacinth combination to conduct the purification research,which simulates the urban river water , the experimental study discovery, compare with the still water condition and the move water condition which the velocity of flow is 1.74cm/s, it has slightly the superiority to NH3-N, TP and DO purifies, the average elimination rate of NH3-N and TP achieves 87.24% and 82.06%，the DO density of the moves water group fluctuation not to be big in the entire experimental process, maintains throughout in the 7.24～8.75 mg/L mg/L stable scope, but to TN and COD elimination rate , the still water group is higher than move the water group obviously, respectively achieves 81.71%, 76.64%.

Abstract: Abstract. Biostimulant and low intensity aeration were used to restore black-odorous water body in Zhupai Creek, Nanning. After 60 days’ experiment, results showed that the removal rate of CODCr、NH3-N and TP were 46.8%、98.7%and 73.3% respectively. The pH value of overlying water changed from 7.61 to 7.92 which would be beneficial to the release of P in the sediment. And the reduction of sediment reached to 5.49 cm. Hence, the remediation effects and speed of biostimulants to the black-odorous urban rivers can be improved greatly by using low intensity aeration.

Abstract: Abstract. Xiawan stream belongs to Xiangjiang River as an important tributary in Zhuzhou city, it is located in Qingshuitang heavy industry zone. The industrial pollution in the zone destroy the ecological environment there, and directly affects the Xiangjiang River water quality, therefore, it also brings some negative impact to the drinking water for people who living in Changsha, Zhuzhou and Xiangtan city group. It needs an urgent regeneration planning to recover the good quality water ecological environment. There will be tow methods to deal with this problem, the first, repairing the canal and both banks to support the ecological recovering; second, using green infrastructure around the river to heal the recently damages and to build an sustainable ecological system.

Abstract: Soil bioengineering is a kind of engineering by using living plant materials to construct the structures with some engineering and ecological functions, which can provide an effective means for the slope stabilization and site restoration of river banks. Experimental site in Liuli River proves that Salix cheilophila Schneid and Salix alba var. tristis are good materials to obtain near-natural riverbank restoration. Soil bioengineering measures of live staking, live fascines and brush layers are effective. After periods time of project implementation, significant effectiveness was obtained on slope stability, habitat improvement, and ecological restoration of river banks. This can provide guidelines for selecting materials and methods to control riverbank erosion. It was concluded that the approach could be widely applied in ecological riverbank restoration in China.

Abstract: To remedy polluted soil, EDTA is choosen when seeing metal Pb (Ⅱ) as target pollutant. There has been a focus on discussion about the infuencs of liquid-solid ratio, EDTA concentration and extraction time on Pb (Ⅱ) extraction rate. And attention is being paid to study the effect of Na2S concentration and pH on Pb (Ⅱ) removal rate with Na₂S as EDTA regeneration medium. The results obtained demonstrate that when the liquid-solid ratio is 10, EDTA concentration is 0.5 mol/L, extraction time is 24 h, extraction efficiency can reach 66.67 %. When the concentration of Na2S is 0.5 mol/L, pH is 10, the 96.67 % Pb (Ⅱ) removal rate can be achieved.

Abstract: The water eutrophication is becoming more and more serious, and the growth of microcystis aerugrinosa must be inhibited. So the research for an effective method for removal of algae in water is becoming increasingly urgent. Several methods for inhabitation the growth of microcystis aerugrinosa were studied. The results indicated that phenol can inhabit the growth of algae effectively and aeration had little effect on the growth of algae. With the oxidation of •OH and the flocculation effect of Fe3+ and its complex flocculation by fenton reagent, it achieved comprehensive pollution removal.

Abstract: A large amount of soluble chemical oxygen demand (COD) exists in the effluent from anaerobic treatment of wastewater at methophilic temperature, which consists of considerable portion of soluble microbial products (SMP). As the anaerobic treatment of wastewater was significantly influenced by temperature, it is great of importance to investigate the SMP from anaerobic reactors operated at low temperature in order to improve the performance. In this study, two lab-scale UASB reactors were performed to treat synthetic glucose and acetate wastewater respectively at an initial concentration of 1000 mg-COD/L at 15 °C. The SMP was found in the effluent from the glucose-fed UASB, and it was 6% of the influent COD concentration. The SMP did not accumulate in the acetate-fed UASB. The average aerobic biodegradability of the SMP was 90% and it was further enhanced by membrane separation of X100 (membrane with 100 k da molecular weight cut-offs). The anaerobic biodegradability of the SMP was 60%, and it was 100% for the fraction in which the molecular weight (MW) was lower than 10 k da. The fraction of low MW (lower than 10 k da) mainly consisted of 31.7% long chain alkanes and 13.6% esters. The aerobic polishing step is an available polishing step for the anaerobic treatment of wastewater at low temperature.

Abstract: In this work, the excitation-emission fluorescent matrix (EEFM) was used to compare the divergence of fluorescent organic properties of the effluents produced from the operation of the bio-stabilizing filter. Four bio-stabilizing filters were simultaneously operated in the combination of both filtered CCL and FS source waters with ozonation (O₃/NPDOC=1) and two different indigenous bacteria taken from CCL and FS source water. It found that, two peak locations, 220-230/330nm, 320-330/410-420nm, existed in the effluent of the four bio-stabilizing filters, and one another peak of 280-290/340 nm was appeared in bio-stabilizing filter using FS source water as a substrate. The fluorescent organic matter, with an excitation wavelength of 220-230 nm and 280-290 nm may be attributed as protein-like, while that of 320-330/410-420nm had the possibility of humic-like. The humic-like matter was accumulated in the effluent from the bio-stabilizing filter during the operational process. Bio-stabilizing filter operated with consistent source water and indigenous bacteria could release higher humic-like fluorescent intensity than that with inconsistent source water and indigenous bacteria.