Study On The Preparation Of Biochar And Its Application In Water Treatment

Biochar is a good adsorbent.It can remove pollutants such as ammonia nitrogen,phosphate,organic dyes,etc.in water by using its complex functional groups on the surface and developed pore structure to reduce water pollution.In the research on sewage treatment It has important meaning.This paper mainly uses corn stalks,leaves,peanut shells,orange peels,walnut shells,and fungus residues as raw materials for biochar.Using the principle of slow pyrolysis,the carbonization temperature is 300℃,400℃,and 500℃,and the carbonization time is 3 Under the conditions of h and 6 h,prepare the biochar required for this experiment,and explore the effect of different carbonization time and carbonization temperature on the yield of the obtained biochar;use potassium dihydrogen phosphate and methylene blue to prepare the phosphorus and Pigment-containing sewage,the initial concentration of phosphorus-containing sewage is 0.5 mg/L,and the initial concentration of methylene blue-containing sewage is 50 mg/L;explore the four factors of contact time,biochar dosage,concentration and temperature for biochar removal The effect of phosphorus and methylene blue on the adsorption performance.An adsorption kinetic model was constructed to explore the internal mechanism of biochar adsorption of total phosphorus and methylene blue.The research results showed that:(1)The biochar yield of corn stalks and leaves is the highest,which can reach more than90%;the yield of walnut shell biochar is the lowest,less than 70%;the yield of biochar of other raw materials is not much different,among which the yield of peanut shell biochar The yield is 87.1%,the yield of orange peel biochar is 83.8%,the yield of walnut shell biochar is80.7%,and the yield of bacterial residue biochar is 88.5%;the carbonization time and carbonization temperature have little effect on the yield.(2)Corn stalk and leaf biochar has a better removal effect on methylene blue.When the initial concentration is 50 mg/L,the biochar dosage is 1.5 g,and the contact time is 160 min,the equilibrium state is reached,and the removal rate is the highest.It can reach 99.3% and96.1%,and the highest adsorption capacity can reach 3310.3 mg/g and 3230.1 mg/g;peanut shell and orange peel biochar has a better removal effect on total phosphorus.When the concentration is 0.5 mg/L,dosing With 7 g of biochar,the contact time is 1680 min to reach equilibrium,the highest removal rate can reach 83.9% and 81.1%,and the highest adsorption capacity can reach 6.0 mg/g and 5.8 mg/g.(3)The adsorption process of total phosphorus and methylene blue by biochar is more fitted to the quasi-secondary adsorption kinetic curve model,indicating that the adsorption process is dominated by chemical adsorption.In the adsorption process of total phosphorus,peanut shells and orange peel biochar have a high degree of fitting,and in the process of methylene blue adsorption,corn stalks and leaves biochar have a high degree of fitting.