[Effects of Heat and Heat-alkaline Treatments on Disintegration and Dissolved Organic Matter in Sludge].

The hydrolysis of sludge organic matter is the rate-limiting step of anaerobic sludge digestion. Because pretreatments can effectively convert the solid organic matter into dissolved organic matter, it can improve the degradation rate and methane conversion rate of organic matter. In this study, the effects of heat and heat-alkaline treatments (two common pretreatments) on the composition, relative molecular weight distribution, and structure of dissolved organic matter in sludge were studied.

[Impacts of alkaline thermal treatment on characteristics of sludge from sewage treatment plant].

Alkaline thermal treatment is an important pretreatment method for sewage sludge. In this paper, in order to optimize the alkaline thermal treatment conditions for sludge pretreatment, four pretreatment parameters ( sludge concentration, pH, temperature and treatment time) were investigated through orthogonal experiments to determine their effects on the sludge disintegration, sludge concentration and sludge morphology of sewage sludge. The experimental results showed that the significance of the four factors on sludge characteristics was in the order of pH > temperature > treatment time > sludge concentration.

[Releases of carbon, nitrogen and phosphorus from sewage sludge at different microwave energy inputs].

In this study, the releases of carbon, nitrogen and phosphorus from sludge treated by microwave irradiation were investigated by batch experiments at two microwave energy inputs (MEIs), 54 kJ and 108 kJ. The final temperatures of the treated samples at these two MEIs were about 56 degrees C and 90 degrees C, respectively. Results showed that the higher MEI was more helpful to release TC, TOC, TN and TP from sludge treated by microwave.

[Impacts of different pretreatments on characteristics of excess sludge].

The impacts of three pretreatments (acid, alkaline and thermal treatments) on the characteristics of sludge were discussed. The results showed that the three pretreatments could disintegrate the sludge and the effectiveness of alkaline treatment was the maximum (about 58.46%) and its SCOD release was also the maximum (2934.

[Non-filamentous sludge bulking caused by low concentration of dissolved oxygen and phosphorus deficiency and its control].

Non-filamentous sludge bulking occurred during sludge acclimation in lab-scale bio-reactors and the characteristics, properties and degrading pollutants capability of non-filamentous sludge were analyzed. Both low DO concentration (0 - 0.7 mg/L) and low ratio of P/BOD5 (0.

[Study on treatment of excess sludge under alkaline condition].

Disintegration of alkaline treatment on excess sludge and its influencing factors were investigated. The results show that alkaline treatment can increase the soluble chemical demand oxygen (SCOD) by releasing the organic materials from cells to water and converting the insoluble ones to soluble ones. The floc structures and the cell structures of sludge were destroyed in the process of alkaline treatment when the treated pH value was above 11.

Effects of thermally pretreated temperature on bio-hydrogen production from sewage sludge.

Hydrogen can be obtained by anaerobic fermentation of sewage sludge. Therefore, in this paper the effects of thermally pretreated temperatures on hydrogen production from sewage sludge were investigated under different pre-treatment conditions. In the thermal pretreatment, some microbial matters of sludge were converted into soluble matters from insoluble ones.