A phosphorus removal biochar adsorbent was prepared from Fenton sludge. The adsorption process was optimized, and its phosphorus adsorption mechanism was discussed. It was found that the phosphorus adsorption performance of biochar prepared from single Fenton sludge (FBC‐400) was better than that of co‐pyrolysis of Fenton sludge and bamboo powder. The optimum condition was that Fenton sludge pyrolyzed at 400°C (FBC‐400). FBC‐400 had a larger specific surface area than that prepared by co‐pyrolysis with bamboo powder. And the high content of iron element could provide a higher surface charge of the biochar, thereby increasing the electrostatic adsorption of phosphorus onto FBC‐400. The phosphorus adsorption was highly pH dependent by FBC‐400, which can enhance electrostatic adsorption and increase adsorption capacity in acidic conditions. The effect of coexisting anion on adsorption performance was mainly affected by CO32−, reducing the adsorption capacity by at least 49%, whereas other anions had no obvious interference. The adsorption process of FBC‐400 accorded with the pseudo‐second‐order kinetic model and the Langmuir model, which indicated that the adsorption process was monolayer adsorption and mainly chemical adsorption, and the maximum saturated phosphorus adsorption capacity was 8.77 mg g−1. The mechanisms for phosphorus adsorption were electrostatic adsorption and inner‐sphere complexing. 1 M NaOH was used for desorption, and the adsorption capacity remained at 81% in the fifth cycle. Practitioner Points The Fenton sludge biochar usage as an adsorbent could be a win‐win strategy to convert waste biomass to valuable ‐ product. The adsorption process accorded with the Langmuir model, the maximum phosphorus adsorption capacity was 8.77 mg/g at 25°C. The adsorption mechanisms were electrostatic adsorption and inner‐sphere complexing. 1M NaOH was used for desorption, and the adsorption capacity remained at 81% in the fifth cycle.

In this study, biochar was prepared using penicillin fermentation residue (PR) as the raw material by different methods. The adsorption behavior and adsorption mechanism of biochar on tetracycline (TC) in an aqueous environment were investigated. The results showed that K2CO3 as an activator could effectively make porous structures, and that biochar with mesoporous or microporous could be prepared in a controlled manner with two kinds of different activation methods, the dry mixing method and the impregnation method. The dry mixing method could create more mesopores, while the impregnation method could prepare more micropores. Microporous biochar (IKBCH) with a high specific surface area could be prepared by the impregnation method combined with HCl soaking, which has an excellent adsorption effect on tetracycline. When the concentration of tetracycline was 200 mg/L, the removal rate of 99.91% could be achieved with the dosage of microporous biochar at 1 g/L. The adsorption process was in accordance with the Langmuir model and the pseudo-second-order model, respectively. The maximum adsorption capacity of IKBCH was 268.55 mg/g (25°C). The adsorption mechanisms were pore filling, π-π interaction, electrostatic adsorption, and hydrogen bond. Its stable and wide applicability adsorption process does not cause ecological pollution in the aqueous environment, and it is a promising biochar adsorbent.

Ammonium molybdate modified bentonite was prepared from bentonite using ammonium molybdate as modified agent, which was used to remove several industrial effluents. It is used in the pretreatment of monosodium glutamate wastewater, slaughtering wastewater and beer wastewater which have high concentration of COD. The suitable reaction condition is ensured and the treatment effects for the treated effluents are compared by ammonium Molybdate-modified Bentonite. The result shows that the ammonium molybdate-modified bentonite is better than other flocculants. The COD removal rate of monosodium glutamate wastewater, slaughtering wastewater and beer wastewater could reach 55.40%, 96.32%, 93.23% respectively. The treatment of slaughtering wastewater is the best and all treated effects meet the pretreatment requirement. Ammonium molybdate-modified bentonite is applied to several industrial effluents in different business. It is a new type flocculant with good flocculation effect and wide application.

Sludge moisture content was investigated at different stages during the test. Pilot-scale sludge drying bed and sludge drying reed beds had the same size of 3 m×1 m×1.3 m, and the bed height consisted of a 65 cm media layer and a 65 cm extra height. The media layer is filled with slag (20 cm), gravel (20 cm), coarse sand (5 cm) and quartz sand (24.5 cm) from the bottom in turn. Unit 1 was a conventional sludge drying bed, unit 2 was a sludge drying reed bed. Unit 1 and unit 2 had ventilation pipes which were mounted on the drainage pipes. Unit 3 was a sludge drying reed bed without ventilation pipe. The waste activated sludge was feed into the three units periodically during the experiment. The experiment investigated the sludge moisture content. At the end of the operation, the sludge moisture content in three units decreased by 18.52%, 22.37%, and 20.68%, respectively. It was found that the dewatering effect of the sludge drying reed bed was better than the conventional drying bed. The effect of plant growth on sludge dewatering is greater than the ventilation, but the difference was not significant.

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Oxide fiber has good thermostability and oxidation resistance at high temperature, is one of the important candidates of the reinforcements of composites for aerospace field. The tensile property at high temperature is one of the critical properties of oxide fiber used in harsh environment, but the related research about domestic 550-grade fiber is rarely reported. In the present work, the tensile property of domestic 550-grade continuous alumina fiber at high temperature and its room temperature tensile property after heat treatment were studied. The relationships between the tensile strength of the fiber and phase transition, microstructures, as well as their internal mechanism were discussed. The results showed that the fiber multifilament and filaments had relatively high tensile strength and strength retention rate up to 1100 ℃. The poor thermostability of amorphous SiO2 at high temperature had obviously adverse effect on the tensile property of the fiber at high temperature above 1200 ℃. The mullite phase was formed by heat treatment at the critical phase transition temperature (1300 ℃), which could improve the fiber tensile strength at 1250-1400 ℃. The tensile strength of SIC550 fiber at 1100 ℃ was close to that of Nextel 720 and CeraFib by considering the effect of different gauge length.

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