| With the development of aquaculture,a large number of high nitrogen and phosphorus and COD of wastewater caused the deterioration of water quality in China.The processing technology and expensive cost caused more difficult for the farm sewage treatment,which resulting in serious water eutrophication.Nowadaays,useing agricultural wastes as adsorbent to treat eutrophic water has became a research trend.However,many nature agricultural wastes don't have good adsorptionare.And how to the recycling of adsorbent and the nutrients are still difficult.To better discuss the processing effect of purifying effect and adsorption characteristics of porous plant substrates on high nitrogen and phosphorus in water.The adsorption process and characteristic of nitrogen and phosphorus plant substrates,including fresh Eichhornia crassipes?Mart.?Solms?ECF?and dry?ECD?,dry straw?OSD?and the sawdust of Cunninghamia lanceolata?Lamb?Hook?CLD?,were studied by static adsorption experiment.The best plant substrates was selected as the composting material?ECP?.And effect of compost and recycling of nitrogen and phosphorus which effected by fermenting bacterias was studied.The main findings are as follows:?1?For single adsorbate experiment,the removal efficiency of PO4--P decreased with the rising of initial PO4--P concentration.Besides,the removal efficiency of NO3--N and NH4+-N decreased with the rising of initial concentration at first,and then the removal efficiency were increased.In addition,the removal efficiency of nitrogen and phosphorus which was adsorbed by plant substrates decreased with time.?2?The adsorption of nitrogen and phosphorus by plant substrate is more suitable for the second adsorption model,chemical adsorption was current on the surface of adsorbents.And the adsorption capacity of fresh water hyacinth was the strongest.and the maximum adsorption capacities of PO4--P,NO3--N,NH4+-N were 4.75-14.22 mg·g-9?3.93-71.61 mg·g-1?12.82-47.88 mg·g-1.So it as the adsorbents to adsorb the high nitrogen and phosphorus wastewater is suitable.?3?Coexisting ions had serious effect on nitrogen and phosphorus adsorption by plant substrates?the NH4+-N was adsorbed by CLD was excepted?.However,NH4+-N sorption by CLD increased with PO4-P and NO3--N coexisted.The adsorption rates of nitrogen and phosphorus which was adsorbed by water hyacinth and straw decreased while the ions was coexising,but the maximum adsorption capacities was increased.And the adsorption effect of phosphorus was special.When the concentration of phosphorus was low,the adsorption rates of nitrogen and phosphorus which was adsorbed by water hyacinth was increased,and the maximum adsorption capacities was decreased.?4?For biogas slurry experiment,the adsorption capacity of ECD on TN,COD,TS was the strongest.And the adsorption capacity of ECF on NH4+-N was the strongest.For the adsorption of phosphorus,the removal rate of fresh water hyacinth was the highest in the first two hours of adsorption,and the removal rate of straw straw was the highest in the last three hours.The results which was fitted by the second adsorption model showed that ECF had the greatest potential for total nitrogen and ammonia nitrogen adsorption.The maximum adsorption capacity of ECF to TN and NO3--N was 81.15 and 17.95 mg·g-1,respectively.The accumulation adsorption capacity of ECD to COD and TS in 5 h was 899.8 ? 252.51 mg·g-1.?5?The addition of pollutants in biogas slurry with water hyacinth can significantly increased the content of nitrogen,phosphorus,potassium and total nutrient in organic manure which were composed by it,and the content of heavy metals did not change significantly.The main nutrient content,moisture,pH and heavy metal content of Organic fertilizer are meet the national Ministry of Agriculture organic fertilizer standards.The content of total nutrient?including N,P,K?and most of the heavy metals in the organic manure which fermented by ECP were significantly higher than those in others.The total nutrient content was higher than 13%,but the content of organic matter was relatively low.The total organic matter and total nutrient content of the organic fertilizer which was inoculated the multifunctional bacteria?JDC?were higher. |
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