Advanced Materials Research Vols. 550-553

Abstract: The aim of this study was to investigate ammonia removal from the effluent of a full-scale biofilm reactor treating pesticide wastewater through the formation of struvite (MgNH₄PO₄•6H₂O). The requirement of magnesium and phosphate ions for precipitation was met by adding MgO and Na₂HPO₄. Different NH₄⁺:Mg²⁺:PO₄^3- molar ratios were tested in batch reactors to optimize the precipitation conditions. Ammonia was reduced to 25 mg/L from an initial concentration of 210 mg/L at the highest ratio tested (1:1.2:1.3), equating to 88% removal. However, the extent of ammonia removal was only slightly affected when the N:Mg ratio was reduced from 1:1.2 to 1:0.6; dropping to 83% from 88% on a percentage basis. Struvite precipitation can be easily incorporated within the existing post-treatment section of the full-scale plant, providing the pesticide manufacturing facility with a reliable backup process for its nitrification system.

Abstract: The abundant biomass from palm oils can be converted into valuable product via pyrolysis process. In this research, the pyrolysis of sustainable oil palm solid waste, empty fruit bunch (EFB), was performed using a static batch reactor in a tubular furnace. The bio-solid waste material obtained was treated with hydrophobic solution (methyl ester) and then impregnated with bio-oil substrate obtained from the pyrolysis. The modified bio-solid waste material was then tested for carbon dioxide capture. SEM results indicated presence uniform and sticky-like material on the surface when further treated with bio-oil substrate. Though, TGA results indicated that addition of hydrophobic solution and bio-oil reduced the thermal stability of the EFB bio-solid. At higher temperature of 150 – 3500C bio-oil impregnated sample indicated little amount of volatile components with carbon residue of 85.39%. The FTIR results of the hydrphobic impregnated bio-solid waste indicated a unique broad peak among all the samples at 620.05cm^-1 which shows the presence of bending stretch carbon dioxide. This shows that bio-oil modified bio-solid char obtained from EFB has the capabity of capturing CO₂.

Abstract: This study use purely bacteria on suitable condition, eliminate other bacteria come in life-form bacteria. Through the orthogonal experiment obtains the optimum condition of sodium alginate fossilization bacillus subtilus pellet to chrome adsorption, and discusses the influence of single factor to the sodium alginate fossilization bacillus subtilus pellet to chrome adsorption, including the time, the temperature,pH, the initial adsorbent density, the speed of the shaker, the absorbent which the different periods of growth bacterium does, coexistent ion, desorption. From the research, we know the maximum adsorption rate to chrome is about 80%. Dynamics research indicated that in the several methods of the Sphingomonas-paucimobilis of chrome , the methods of embedded micro-organisms embodies much advantages ,as operating easily, effecting clearly, less pollution, costing low, etc.

Abstract: In the assessment of health risks of environmental pollutants, both conventional methods and probabilistic methods based on the use of cumulative probability plots have been used. Probabilistic risk assessment has the advantage that the statistical distributions of both the exposure data set and the adverse effect data set are taken into account in risk characterization. In addition, the method of overall risk probability (ORP) has been used to quantify the overall risk probability of adverse effects for the population samples. The disadvantage is that many more data points are needed to obtain the cumulative probability plots and the calculation of the ORP from the probability plots is more complicated. In this paper, a simplified computational method for the estimation of the ORP was developed. In this method, an overall risk factor (ORF), as an estimated value of the ORP value, was obtained from the mid-point of an exposure exceedence curve. The ORF can also be obtained from an inversed cumulative probability plot of the exposure curve, thus eliminating the needs for the use of the exposure exceedence curve and the numerical integration of the exceedence curve in ORP computation. The use of ORF method was illustrated with a practical example and the results indicated that the values of the ORF and ORP are about the same.

Abstract: Experiment was made to study heavy metal ion mining wastewater.The effect of Temperature, pH, Initial concentration, coexisting ions and time on the performance of Nanomaterials were investigated. Results showed that removal efficiency of heavy metal ions was higher than 85% and Pb²⁺ concentration in permeation liquid was lower than 0.5 mg/L,which verified that Nanomaterials is effective for the removal of heavy metal ions, and the concentration liquid can be reclaimed.

Abstract: This paper designed and investigated the pyrolysis combustion process of the sewage sludge, based on the combustion properties and self-sustained combustion conditions of the sewage sludge. The water content of the sludge was first reduced to less than 55% through the mechanically dewater. Then, the sludge was combusted in the pyrolysis-combustion chain grate stoker. A sewage sludge pyrolysis-combustion system was designed, with the processing capacity of 15 tons of sawage sludge per day. The results of the pilot test show that a dynamic equilibrium was reached among the drying, pyrolysis, gasification and combustion process. In addition, the emission of the pollutant reached the national standard of the pollutant discharging criteria. The system owns the advantages of less investment, low operation cost and environmental friendliness. Furthermore, the system may solve the problem of the excess sludge accumulation of the wastewater treatment plant. The waste heat can be recycled, and the burning ash can be used as construction materials.

Abstract: As a kind of rich resources and cheap materials, natural zeolites because of its unique adsorptive characteristics were widely used in drinking water purification at present. The paper introduced the modification methods of natural zeolites mainly acid or alkali, salt, heat treatment, change silicon aluminium and etc. And introduces the application of zeolite in drinking water purification mainly include: fluoride, ammonia nitrogen and deferrizers and etc.

Abstract: Soil organic carbon (SOC) content and density (SOCD) were studied under six land use patterns of Natural forest, Schima superba plantation, Coniferous forest, Bamboo forest, Orchard, and Abandoned land in the Dongjiang River valley of Guandong province, China. The results showed that surface soil (0~25 cm) organic carbon content and soil organic carbon density had significant difference (P -1) > Schima superba planted forest (21.1±0.79 g•kg^-1) > Bamboo (20.9±0.53 g•kg^-1) > Coniferous forest (15.65±0.93 g•kg^-1) > Orchard (15.22±0.61 g•kg^-1) > Abandoned land (8.69±0.38 g•kg^-1), and Natural forest (67.16±2.31 kg•m^-2) > Bamboo (60.08±1.53 kg•m^-2) > Schima superba plantation (52.8±1.86 kg•m^-2) > Coniferous forest (47.17±2.66 kg•m^-2) > Orchard (43.03±1.56 kg•m^-2) > Abandoned land (31.48±1.2 kg•m^-2), respectively. Natural forest was the highest in both soil organic carbon content and soil organic carbon density, and Abandoned land the lowest. The findings suggested that a close-to-nature way of afforestation and forest management played an important role in increasing forest carbon sinks.

Abstract: ABSTRACT. SBR (Sequencing Batch Reactor) was investigated for the treatment of OCC pulping wastewater in this paper. This study includes the design of the SBR device and its control system, the test of start-up of the SBR, running of the reactor by treating the wastewater. During the start-up process the activated sludge was cultured and acclimated. After acclimation the removal efficiency of CODcr can reach around 80%. Following investigations were focused on evaluation of the treatment efficiency and the reactive cycle during running the SBR. The experimental results showed that the running parameters of SBR reaction system were Fill 2.0 h, React 12.0 h, Settle 1.0~2.0 h, Drain 0.5h, Idle 4.0h. Under these conditions the removal rate of COD can reach 94%. So the performance of SBR for the wastewater was satisfactory as the wastewater had 1500~2500mg/l of COD. The cyclic operation of SBR used in this study proved more effective in treating the wastewater.

Abstract: The impact of SRT on simultaneous nitrification and denitrification (SND) in the Carrousel Oxidation Ditch was carried out based on pilot-scale to treat low COD/TN municipal sewage. The impact factor, sludge retention time (SRT), was investigated on the occurrence of SND. The experiment results showed that in the oxygen-deficient environment whose DO was 0.3 mg/L, R of 50%, MLSS of 4000 mg/L, the treatment efficiency achieved the best with SRT of 20 d, the COD, ammonia nitrogen, total nitrogen (TN) of effluent were lower than 32 mg/L, 5 mg/L, 13 mg/L, respectively, which was observed efficient phenomenon of SND. Overall, these results demonstrated that the Carrousel Oxidation Ditch with the occurrence of SND could have the potential to treat low C/N sewage.