Advanced Materials Research Vols. 356-360

Abstract: Owing to toxicity of pharmacy wastewater to microbe, commonly used biodegradation is often limited in application; accordingly exploiting new ways of the wastewater treatment with high efficiency is a hot topic. As a new efficient advanced oxidation, pulsed corona discharge combining with ozone is attracting more and more attention. In this study, a special reactor was designed, in addition, the removal of TOC(Total Organic Carbon) and COD (Chemical Oxygen Demand)of simulant pharmacy wastewater containing hydroquinone (500mg/L) by pulsed corona discharge combining with ozone were investigated . It was showed that the TOC and COD removal (53.8% and 72.3%) by the combined technology was much higher than by using the two techniques in series when all the samples were treated 40mins.The two methods in combination have a synergistic effect. TOC and COD removal could be improved obviously when NaCl feed concentration increased from 0 to1000 mg/L, yet further increase in NaCl feed led to a markedly decrease removal efficiency of TOC and COD.

Abstract: The excess sludge from wastewater treatment plants can be converted to methane or hydrogen through appropriate anaerobic digestion process, which is an effective way to prevent pollution and recover biomass energy. However, the lower conversion rate that results in long residence time and large digester volume limits its application. The ultrasonic technology can be applied to effectively improve the biomass conversion of excess sludege during anaerobic digestion process. In this review, the mechanism and main influencing factors of ultrasonic enhancement were summarized, and the current research situation and future development were presented as well.

Abstract: Together with the chemical analysis as well as XRD and DTA, effects of steam and autoclave treatments on structure characteristics of basic oxygen furnace slag (BOFS) and electric arc furnace slag (EAFS) are investigated. The results show that steam and autoclave treatments on slag contribute to the conversion of f-CaO and f-MgO to Ca(OH)₂ and Mg(OH)₂ ,which improve the volume stability of slag by reducing the contents of free lime and periclase, and the autoclave treatment is more effective. Meanwhile, for the utilization of steel slag, the effects on the volume stability by CaO and MgO that were wrapped in eutectic in the crystallite form should be a key factor, besides the contents of f-CaO and coarse periclase crystalline. The thermal reactivity of slag treated by steam and autoclave increased, especially the reactivity of elemental iron and wuestite. The reactivity of EAFS increased more significantly at high temperature due to its higher content of iron.

Abstract: As more and more natural gas fields with high content of CO₂ have been exploited, it is a strategic significance to capture and take good use of the waste gas while reducing CO₂ emission to atmosphere. Pipelines have been identified as the primary means of transporting CO₂ from point-of-capture to storage sites, but there is little published work on the economics of CO₂ pipeline transport study either exclude transport costs or assume a given cost per tonne of CO₂ in addition to capture costs.This paper simulates the CO₂ pipeline transport processes of different diameters by liquid and supercritical phase, and estimates the total costs of different transport cases. By comparing the economic value of different cases comprehensively, the optimal transport option for Dongfang 1-1 gas field EGR program has been analyzed.

Abstract: The waste of office is a major source of municipal solid waste. Taking the imperfect and poor-running recycling system into account, we may start with establishing a pilot recycling system in China’s urban areas, in the hope of exploring its organizational and operational mechanisms. A questionnaire-based survey among the office staff is implemented. According to the results, this paper preliminarily proves the feasibility of setting up an efficiency-led office waste recycling system. What’s more, the framework and operational mechanism of a new pilot recycling system is designed.

Abstract: Coking wastewater is the poisonous wastewater with complicated components produced in the coking process and it is difficult to be degraded. The paper studies the static treatment effect of metallization pellet with high carbon (MPHC), sponge iron, 45＃steel chips and cast iron chips on coking wastewater. And the four substances are characterized by scanning electron microscope (SEM). The results indicate that the degradation performance of MPHC on coking wastewater is higher than that of sponge iron, 45＃steel chips and cast iron chips. There are abundant pores on MPHC, and the activated carbon has strong adsorption capacity, and it can adsorb the organic pollutants on the surface of primary battery, and promotes the progress of iron-carbon internal electrolysis reaction.

Abstract: Coking wastewater produced in the coking process is poisonous and difficult to be degraded. Coking wastewater was treated by fixed bed reactors of metallization pellets with high carbon (MPHC). In this paper, it studies the effect of removing phenols, cyanide, chemical oxygen demand（COD）and ammonia nitrogen in coking wastewater by MPHC. The results show that MPHC has good degradation effect on phenols and cyanide in coking wastewater, and the degradation rate reaches to 99.88% and 99.81% respectively; and has certain degradation effect on COD, the degradation rate is 70.61%; has poor degradation effect on ammonia nitrogen. The results of FT-IR indicate that the degradation of organic pollutants in coking wastewater by MPHC is not simply adsorption, but is removed completely.

Abstract: Railway washing wastewater, containing a large number of carbohydrates, fat, protein, cellulose, and other organic pollutants, will cause serious pollution, result in production of foul-smelling matter, impact on the survival of aquatic life and hinder the sustainable development of railway transport, if the wastewater is directly discharged into the nature water body. At present, the main treatment processes for railway washing wastewater are physical and chemical treatments which are inefficient, unstable and expensive and can not meet the requirements of water recycling, so a treatment process suitable for railway washing wastewater is badly in need of research and development. The constructed rapid infiltration (CRI), an ecological wastewater treatment technology, excels at treating wastewater especially toward CODcr，BOD5 and SS. But the efficiency of TP removal in CRI is inefficient. In order to improve efficiency of TP removal, sponge iron is added to the traditional CRIs. To determine the feasibility of railway washing wastewater disposal by CRI, the washing waste water of Chengdu Railway Administration was selected as test sample. Traditional CRIs and improved CRIs were applied to treat the washing waste water and degradation kinetics characteristics of TP were studied, the results show that: when average TP concentration of inflow is 6.24mg/L, in traditional CRIs and improved CRIs, average TP concentration of outflow are 4.17mg/L and 1.40mg/L respectively, average efficiency of phosphorus removal are 33.03% and 77.50% respectively; as the TP concentrations of inflow increase, TP concentrations of outflow increase accordingly but the removal rates of TP are stable. Because of addition of sponge iron, the removal rate of TP in improved CRIs is more 44% than traditional CRIs. The results of this experiment show that: Improved CRI is a clean, cheap and ecological technology which is suited for the railway washing wastewater treatment and can promote the sustainable development of traffic engineering, reduce the negative impact on the ecological environment and make railway traffic compatible with resources, environment and social economy.

Abstract: Sludge from tannery was solidified and stabilized by using lime, PFA and cinder as the solidifying agents，investigation of solidifying agents affect toxic heavy metals in tannery sludge and the optimum conditions of sludge solidification/stabilization were analyzed. The results showed that under the dosage of lime, PFA and cinder were 0.12kg/kg, 0.02kg/kg and 0.08kg/kg respectively, and curing time was 6 days, the compressive strength of the solidified sludge block reached 884KPa while the moisture content of the solidification block was 30.2%，which met with the standards of landfill. Compared with the untreated tannery sludge，the concentration of Cu、Pb、Zn、Ni and COD of the leaching from the sludge solidification block was reduced by 92.1%、96.7%、92.8%、88.9% and 75.9% respectively，the Cr、Cd、and Mn were undetectable.When lime and PFA ratio was 6:1, the solidified block have good synergistic solidification effects.

Abstract: Environment Protection and Food Security are included in the key issues of people’s livelihood during the Twelfth Five-Year Plan. The waste oil, which direct discharge of it would pollute the environment, thus threatening the environment; what’s more, it would do great harm to the health of people, challenges food security seriously. Enhancing the supervision of waste oil is an important task of social problem. Based on the practical researches in some areas such as Beijing and Chongqing, with other studies about the same subject and comparison of the experience abroad, this article elaborates on the current status, causes and hazards of the waste oil systematically. It also has put forward a sound system of supervision. All of these are important for people to have better understanding and complete solution of the problem.