Applied Mechanics and Materials Vols. 448-453

Abstract: Through the four types of watersheds construction in Shandong province such as ecological and water clean type, ecological and economic prosperous type, ecological and landscaping type and ecological and flood preventing type, the former soil and water loss in ecological small watersheds are effectively controlled. Based on the analysis of construction practice in Shandong province, this article puts forward the general principles and key technologies, which is expected to improve the construction of watersheds.

Abstract: Chlorinated nitroaromatie compounds, which are widely used for synthesis industry of chemicals, pharmacy and pesticide, are listed on the priority pollutants by EPA and Chinese MEP. In this study, we investigated biocatalyzed electrolysis systems (BESs) with a bio-cathode seeding with enriched inoculum for the degradation of a typical chlorinated nitroaromatie compound: para-Chloronitrobenzene (4-CNB). Batch test results showed that the 4-CNB (30mg/L) would be completely degraded within HRT of 30 hours with 0.5V power supplied and NaAc (1g/L) as sole carbon source. The optimum operation conditions of CNB degradation in BESs was 50mM Phosphate Buffered Saline (PBS) (pH=7) and the distance of electrode is 1cm. But the 20mM PBS and the distance of 3cm would be acceptable and economic.

Abstract: Weishan County gets its name for Weishan Lake, also known as Nansi Lakes because it consists of the four major lakes (Small Weishan, Zhaoyang, Dushan and Nanyang). Weishan Lake is an important water source in Shandong Province and one of the main impounded lakes in the East Route Project of Water Diversion from the South to the North. In order to ensure the water quality, the relevant cities and counties of Shandong Province attach great importance to water pollution control around the Weishan Lake. According to field investigation and analysis of present situation of the project area, common problems existed in pond culture along Weishan Lake were found out, meanwhile the targeted solutions for them were given aiming at the transformation of snakehead farming pond by ecological engineering, that focus on an establishment of the demonstration base so as to demonstrate a mode of aquiculture that is environmentally friendly, to enhance ecological health of aquiculture for sankeheaded, and to provide a strong guarantee for the East Route Project of Water Diversion from the South to the North to have a good water quality.

Abstract: In this study, photo-bioreactor designed with 4 L of volume to cultivate Chlorella sp. was conducted for comparing the differences of biomass increase among three gas flow rates. All experiments were controlled at light reaction of 12 hrs. with 1,700 lux. The organic fluorescence of algae, expressed in excitation emission fluorescent matrix (EEFM), was obtained from algal solution deducted from EEFM of the filtrate obtained from the filtration of algal solution using 0.2 μm membrane filter. Also, the surface charge and functional group for Chlorella sp. were respectively measured by zeta meter and Fourier transform infrared spectroscopy (FTIR). Biomass was measured by absorbance wavelength of 683 nm or dried biomass. Current results reveal that high flow rate produced more biomass than low flow rate did. Regarding to the fluorescent characteristic derived from Chlorella sp., two peaks were appeared in both wavelengths of excitation and Emission (EX/EM) respectively located at 280/330 nm (protein-like) and 440-480/680 nm (pigment). For the variation of autofluorescent intensities during algal incubation, algal image captured by epofluorescent microscope equipped with CCD (Charge-Coupled Device) could be further dealt using image software, showing that there were divergences of fluorescent intensities derived from varied amount of protein-like substance or pigment. Functional group of Chlorella sp. analyzed by FTIR, hydroxyl, peptidic bond, carboxylic acids and polysaccharide were existed with variations of transmittance (%) while gas flow rate was changed.

Abstract: Analysis of the causes of dust brick and tile production enterprises, from the impact on human health, the factory machinery and equipment wear, impact on environment protection, expounds the harmfulness of dust, and discusses the type, structure and function of the filter, as well as the precipitator combined use method and way to control dust.

Abstract: The biodegradability of aged landfill leachate is low, and the treatment effects of common processes are very poor. This paper explored the effects of the Ultrasound/Ultraviolet - Aged Refuse Bioreactor combined process on aged landfill leachate. The main results were as follows: 1The optimum power of ultrasound was 100 W, and the optimum wavelength of ultraviolet was 254 nm. The removal rate of COD was 27.33% and the value of BOD/COD ratio was increased from 0.1 to 0.35 after the treatment of Ultrasound/Ultraviolet process. Therefore, the biodegradability of the leachate was improved, which might meet the demand of subsequent biological treatment. 2The COD removal rates of the two-stage series aged refuse bioreactor were both kept above 50% during the experiment and this process had a strong capacity of resistance to impact load. 3The COD removal rate of the combined process was over 80% as a whole without any pretreatment, and it has positive significance for the treatment of aged leachate.

Abstract: Landfill leachate treatment is a major problem to be solved in the field of environmental protection, and ammonia nitrogen is one of the major pollutants in landfill leachate, whose processing technology needs further improvement. In this paper, ultrasound/ultraviolet co-oxidation technology was directly applied to the treatment of high concentration landfill leachate without the pretreatment operations of dilution, filter, and adjusting the pH conditions. The results showed that: ultrasonic and ultraviolet had certain effects on the ammonia nitrogen removal, and the ammonia nitrogen removing effects became better when the ultrasonic power was greater, or the ultraviolet wavelength was shorter. When the ultrasonic power was 100 W, the ammonia nitrogen removal efficiency was 25.2%, and the UV of 254 nm could decompose 20.2% of the ammonia nitrogen in landfill leathate. In the condition of aeration, ultrasonic and ultraviolet had good synergistic effect on leachate ammonia nitrogen treatment. When the ultrasonic power was 100 W, UV wavelength was 254 nm, and the aeration rate was 150 L/h, the ammonia removal efficiency of high concentration leachate (ammonia nitrogen concentration of 1800 mg/L) reached 98.5% after 6 hours. The paper's research results provide a useful reference for the removal of landfill leachate ammonia nitrogen.

Abstract: According to the directory of hazardous waste, Waste methanol belongs to the hazardous waste. Production of methanol will produce ethers, ketones and other impurities. During the distillation for waste methanol, high concentrations of distillation waste will be produced. In this paper, waste methanol recovery process in a southern chemical plant was adopted as the research object. Methanol and distillation waste were sampled and analyzed, combined with domestic research findings about waste methanol and other organic pollutants, the emission and pollution characteristics of waste methanol were discussed. The results show that Ethers and ketones are the main contaminants of methanol; it has potential hazards for products with such methanol as raw materials. The distillation waste has high COD concentration, containes methanol, mixed alcohol and other toxic substances, which has the risks for environmental pollution and human health.

Abstract: Cr⁶⁺ wastewater treatment by the self-designed the electric flocculation device has been investigated. This paper analyzed the factors such as the reaction time, reaction voltage, Electrode current, the electrolyte concentration, as well as Reaction pH on the effect of Cr⁶⁺ wastewater treatment. Comparison of previous studies: Under neutral condition, reaction current was 4.5A,reaction voltage was 25V, electrolytic time was 25 minutes. After processing Cr⁶⁺down to concentration of 0.02mg/l, which reached the national sewage discharge standards (GB8978-2002).

Abstract: Photoelectric catalysis oxidation process, which employs UV lamp as light source,TiO2 electrical as anode and Pt as cathode, has been used for degrading Organophosphorus scale inhibitors.The effects of additional electrical field intensity and pH of the solution on the removal rate of organophosphorus are investigated. The results show that the best additional voltage during the process of photo electrocatalysis is 8V, pH=8.0, and reaction time 10min, the organophosphorus removal rate of HEDP reaches 93.35%, the organophosphorus removal rate of PCAC reaches 96.0%.