BackgroundElectrochemical oxidation has attracted wide attention in wastewater treatment because of its strong oxidation performance and ease of control. This work investigated the feasibility of electrochemical treat...
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BackgroundElectrochemical oxidation has attracted wide attention in wastewater treatment because of its strong oxidation performance and ease of control. This work investigated the feasibility of electrochemical treatment using a Ti/RuO2-IrO2 anode as an advanced treatment of coking wastewater. The influential operating factors including current density (9.6-108.2mAcm(-2)) and electrode gap (0.5-2.5cm) were evaluated. ResultsThe current density and electrodes gap had significant effects on COD and NH4+-N removal and the energy consumption. The degradation of COD and NH4+-N followed pseudo-first-order kinetics. In most experiments, high levels of NH4+-N removal (NH4+-N removal ratio>95%) was achieved along with moderate mineralization (COD removal ratio: 60-80%). COD (178.0-285.0mgL(-1)) and NH4+-N (55.0-76.0mgL(-1)) were degraded by 62% and 96%, respectively, at the optimum conditions (electrode gap: 0.5cm, current density: 15.6mAcm(-2)) after 60min treatment. Under this optimal condition, the corresponding energy consumption was 8.60 kWh m(-3) for effluent meeting the discharge standards. Furthermore, gas chromatography-mass spectrometry (GC-MS) analysis indicated that this technique could be employed to eliminate bio-refractory and toxic compounds such as phenanthrene, indole, quinoline and pyrimidine in coking wastewater. ConclusionTi/RuO2-IrO2 anode systems were confirmed to be effective in advanced treatment of biologically pretreated coking wastewater. (c) 2012 Society of Chemical Industry
This paper reports the effects of wheat stalk anaerobic extract and wheat stalk powder on the inhibition of Microcystis aeruginosa in the laboratory, and the broken wheat stalk on the growth of the phytoplankton and z...
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ISBN:
(纸本)9783037857427
This paper reports the effects of wheat stalk anaerobic extract and wheat stalk powder on the inhibition of Microcystis aeruginosa in the laboratory, and the broken wheat stalk on the growth of the phytoplankton and zooplankton in natural water. The results show that: (1) the Wheat stalk Anaerobic extract has inhibitory effect on the Microcystis aeruginosa, the average inhibiting rate was 59%;(2) the Wheat stalk powder has obvious inhibitory effect on the Microcystis aeruginosa, the average inhibitory rate was 74% and the effect increased with the passage of time. The inhibitory rate remained the range of 75%similar to 96% from the 3rd day to 13th day after adding the Wheat stalk powder;(3) In natural water, the addition of broken wheat stalk can cause change of the dominant phytoplankton species in which cyanophyte is not obvious dominant species anymore, and the broken wheat stalk has inhibitory effect on the growth of phytoplankton cells;(4) The addition of broken wheat stalk can promote the growth of poor-middle nutrition species zooplankton in natural water, and make their abundance soars rapidly.
Brackish water was treated with reverse osmosis process. The fouling mechanism of RO and its control method was studied. In the treatment of brackish water, the salt removal efficiency was above 95% and the effluent q...
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ISBN:
(纸本)9783037858226
Brackish water was treated with reverse osmosis process. The fouling mechanism of RO and its control method was studied. In the treatment of brackish water, the salt removal efficiency was above 95% and the effluent quality was up to the standard for drinking water quality (GB5749-2006). The SDI of the influent of RO was less than 5 after the raw water was pretreated by the combination of coagulation and sedimentation process and filtration process, which met the demand of the water quality of the RO influent. If ultrafiltration was added, the water quality of the pre-treatment was better. Coagulation and precipitation was not very effective for the removal of dissolved organic compounds, especially for the removal of organic compounds with molecular amount ranging from 1000 to 10000. The formation of RO membrane fouling can be divided into five stages, which is membrane surface coarseness stage by inorganic substrate, organic compounds adsorption stage, organism adhesion stage, microbial film development stage, and irreversible membrane block stage. The membrane fouling was effectively alleviated by the strategy of first alkali solution cleaning and then acid solution cleaning.
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