Advanced Materials Research Vols. 726-731

Abstract: The purpose of this paper is to compare the effect of disposal of lead with calamus artificial marsh composed with sand and soil and the effect of calamus artificial marsh whose host materials are carbon residue and soil under different currency, and discuss the impact of host material to dispose the lead in waste water. Results show that calamus artificial marsh is effective to dispose the lead in waste water. After compared the effect of calamus artificial marsh with two host materials, we discover that calamus artificial marsh which is composed with sand and soil could work better in disposal of the lead in wastewater, which could be a proper artificial marsh.

Abstract: In this study, the sorption of heavy metals (Cu²⁺, Pb²⁺, Zn²⁺ and Cd²⁺) from simulated metallurgical wastewater by sepiolite under different dosage, pH, adsorption time and temperature conditions was investigated. The results showed that adsorption increased with the increase of adsorbent dosage until the adsorption equilibrium was reached. When the pH is 6, adsorption of heavy metal ions by sepiolite was in the order of Cu²⁺ > Zn²⁺ > Pb²⁺ > Cd²⁺ and removal rates of the metal ion were 91%, 90%, 91%, 84%, respectively. The effect of adsorption time on adsorption was not significant. At room temperature, with the adsorption time 45 min, the adsorption of metal ions is almost saturated, adsorption of Cu²⁺, Pb²⁺, Cd²⁺ and Zn²⁺ was 13.05mg/g, 85.47mg/g, 62.36mg/g and 15.67mg/g, respectively.

Abstract: Enriched domestication in SBR was used to improve the proportion of aerobic denitrifiers in activated sludge, and actual power plant wastewater was treated, which proved the existence of aerobic denitrification. But at the later stage, because of carbon deficiency, aerobic denitrifiers were inhibited and NO₃^--N accumulated. Sodium acetate used as external organic carbon source was added when reaction carried on 3.5 hours to improve the COD/NH₄⁺-N ratio from 6.5 to 10, effluent NO₃^--N concentration was 3.6 mg\L, average removal efficiency of TN was 90%, which could improve the aerobic denitrification performance of whole system effectively.

Abstract: The Ti/SnO₂-Sb₂O₃ and Ti/SnO₂-Sb₂O₃/PbO₂-Fe electrodes were prepared by thermal decomposition method. Using these two electrodes as anodes, two electro-catalytic oxidation processes were introduced to treat three simulant dye wastewaters, which respectively prepared by the dyes of acid orange II, alizarin red and methylene blue thrihydrate. The results show that these dyes with 100mg/L concentration were degraded by the optimal electrodes. When the current density was 75mA/cm², the electrolyte concentration was 12g Na₂SO₄/L, and the degradation time was over 60 minutes, the removal ratio of acid orange II was around 80%, alizarin red was above 65%, and methylene blue thrihydrate was just 45% or so. The results that the removal rates of different dyes were different were explained based on the dyes chemistry structure. It was obtained that the chromophoric group of dye is more complex, the degradation process is more difficult.

Abstract: In the present work, a novel compound purifying tank was adopted in the rural sanitary sewage treatment. The cultivation and acclimation of biological film could be completed in a short start-up by aerobic precoating. According to the running results,the average COD removal rate reached 59.62%,and the removal efficiency of TP was 33.4%.For the denitrogenation,the removal rates were not remarkable (21.7 to NH₄⁺-N,21.9 to TN),but the large removal quantity of NH₄⁺-N and TN were abtained as 8.58mg/L and 9.12mg/L,respectively. The study suggests that the compound purifying tank is a potential alternative for rural sanitary sewage treatment.

Abstract: The organic compounds in radioactive wastewater were treated using ozone oxidation technology. The influence of pH, ozone dosage, reaction time, initial COD, H₂O₂ on the removal of COD by ozone was investigated. The results showed that the removal efficiency of COD in the alkaline condition was higher than that of acidic condition, the COD removal rate increased with increasing ozone dosage, reaction time, H₂O₂ dosage, decreased with increasing initial COD. Under the conditions of COD 362 mg/L, pH value 9.0, ozone dosage 7.86 mg•L^-1•min^-1, reaction time 30 min , the removal rate of COD was 25.9%; the removal rate of COD increased to 37.8% when 0.2 ml H₂O₂ was added in addition.

Abstract: Based on the systematically describing of the producing and living waste water treatment process in Faende Mining Co.,Ltd.,in Shagou, Luoning, Henan Province, the production and living waste water treatment effect was analyzed deeply. The comparing results of before and after treatment showed that the design of the treatment process in the mine was reasonable, the sewage treatment worked well, and the effluent concentration of has reached the first class of "integrated Wastewater Discharge Standard" (GB8978-1996), among which the concentration of the two indexes, Lead and Zinc, has achieved the specific standard which is more strict than the first class of "integrated Wastewater Discharge Standard" (GB8978-1996).

Abstract: The problem of municipal solid waste (MSW) has been a serious threat to the health of residents and the ecological environment of city. Waste classification can maximize waste resource utilization, reduce the amount of garbage disposal, improve the quality of the living environment, and is the fundamental solution to the problem of "garbage siege" phenomenon. However, over the years, our country MSW classification recycling work remains stagnant. It is proposed that the classification recycling of MSW in China can choose the clearest, simplest and most harmful areas, start from the household appliances, electronic waste, vegetable waste, packaging and kitchen waste recycling, to recycle social resources effectively and realize the sustainable development of city.

Abstract: Many cities in China are facing a "junk siege" dilemma, municipal solid waste classified recycling is one of the effective disposal methods of garbage scientific management, and is also the best way to waste reduction, recycling and harmless, However our municipal solid waste classification recycling remain stagnant, This paper argues that it is because of many obstacles that municipal solid waste classification recycling face makes municipal solid waste classification recycling have little effect, which include public awareness needs to be improved, the limitations of traditional garbage classification, lack of corresponding laws and regulations, garbage recycling facilities not complete and the corresponding theoretical issues remain to be explored etc.

Abstract: In this paper, modified rice straw was investigated for its Cu²⁺removal ability from aqueous solution. The effects of environmental factors on metal biosorption were studied under static state, including initial concentration of metal ions, sorption time, initial pH value and adsordent dosage. In addition, the relevant equilibrium, kinetics were discussed. The results showed that the rice straw which was modified by NaOH had been improved greatly in its Cu²⁺removal ability. The rice straw had good effects on adsorption of low concentration of Cu²⁺ solution. The adsorption data fit Langmuir isotherm model well, the maximum adsorption capacity for Cu²⁺ reached 8.48 mg·g^-1. The adsorption of Cu²⁺ on the modified rice straw was a very rapid process, the kinetics fit a pseudo-second-order equation well. The pH value had prominent effect on the removal rate of Cu²⁺, adsorption efficient could reach over 92% when pH value was between 5 and 6.5. With increasing adsordent dosage, the removal rate of Cu²⁺ increased.