CN-118724314-B - Method for treating high ammonia nitrogen wastewater and recycling

Abstract

The invention discloses a method for treating high ammonia nitrogen wastewater and recycling the same. A method for treating high-ammonia-nitrogen waste water and recycling the same includes such steps as inoculating microalgae in TAP culture medium without nitrogen source, nitrogen starvation culture for 4-6 days, adding zeolite to the high-ammonia-nitrogen waste water to be treated to lower its TAN concentration to 200-300mg/L, co-culturing the microalgae and yeast, removing the waste water from step (2), regulating its pH value to 6.0-7.0, and treating for 6-8 days. The method provided by the invention can treat the culture wastewater with higher nutrient elements, especially the culture wastewater containing high ammonia nitrogen and organic matters, and realize wastewater reclamation so as to reduce cost and improve economic benefit.

Inventors

• LI HUANKAI
• LIU HUI
• HE JUNJIE

Assignees

• 仲恺农业工程学院

Dates

Publication Date

20260505

Application Date

20240329

Claims (6)

1. 1. The method for treating the high ammonia nitrogen wastewater and recycling the high ammonia nitrogen wastewater is characterized by comprising the following steps of: (1) Inoculating microalgae in TAP culture medium without nitrogen source, and performing nitrogen starvation domestication culture for 3-6 days to avoid death caused by excessive decomposition of intracellular proteins, wherein the culture temperature, illumination intensity, shaking table rotation speed and light-dark period are respectively set to 22-30deg.C, 100-200 μmol/(m 2 s), 80-150 rpm and 12/12-16/8 h; (2) Adding zeolite into the high ammonia nitrogen wastewater to be treated to reduce the TAN concentration of the high ammonia nitrogen wastewater to 200-300 mg/L, wherein the ammonia nitrogen concentration in the high ammonia nitrogen wastewater is more than 300 mg/L, and the total organic carbon is 8000-20000 mg/L; (3) Co-culturing microalgae and yeast subjected to nitrogen starvation domestication culture according to a mass ratio of 2:1 to treat the wastewater obtained in the step (2), inoculating the microalgae into the wastewater obtained in the step (2) according to a biomass of 0.1-0.3 g/L, adjusting the pH value of the wastewater to 6.0-7.0 every day, and treating for 6-8 days, so that the TAN removal rate of the obtained wastewater is more than 95% relative to that of high ammonia nitrogen wastewater to be treated.
2. 2. The method of claim 1, wherein the microalgae cells are inoculated in the culture medium of step (1) at a concentration of 1 x 10 7 -10×10 7 cells/ml.
3. 3. The method of claim 1, wherein the microalgae in step (1) comprise chlorella vulgaris and chlorella pyrenoidosa.
4. 4. The method according to claim 1, wherein the pH of the wastewater is adjusted to 6.0-7.0 daily in step (3) using hydrochloric acid.
5. 5. The method for treating high ammonia nitrogen wastewater and recycling the same as defined in claim 1, wherein the method is applied to the treatment of the high ammonia nitrogen wastewater.
6. 6. The use according to claim 5, wherein the ammonia nitrogen concentration in the high ammonia nitrogen wastewater is greater than 300 mg/L and the total organic carbon is 8000-20000 mg/L.

Description

Method for treating high ammonia nitrogen wastewater and recycling Technical field: The invention relates to the technical field of ammonia nitrogen wastewater treatment, in particular to a method for treating high ammonia nitrogen wastewater and recycling the high ammonia nitrogen wastewater. The background technology is as follows: With the rapid development of the global livestock industry, a large amount of nutrient-rich wastewater is produced. The concentrations of Chemical Oxygen Demand (COD), total Organic Carbon (TOC), total Nitrogen (TN), total Ammonia Nitrogen (TAN) and Total Phosphorus (TP) in the wastewater reached 7786, 2094, 2048, 1820 and 124.7 mg/l, respectively. Wherein high concentrations of total ammonia nitrogen and total organic carbon can affect the efficiency, stability and safety of conventional processing techniques, including chemical and biological processes. Development of a new high-carbon nitrogen wastewater treatment technology is important for recycling the cultivation wastewater. In order to offset the treatment cost and realize the recycling of resources, the nutrition recovery can be carried out in the wastewater treatment process so as to produce high-value biomass. As a prominent case of "turning waste into wealth", microalgae having good nutrient salt assimilation performance and high-value components have been widely cultivated for wastewater treatment. The microalgae can efficiently assimilate carbon, nitrogen, phosphorus and various trace elements in the wastewater so as to reduce the discharge of high-carbon nitrogen wastewater. Meanwhile, the microalgae can utilize carbon dioxide to carry out photosynthesis to generate oxygen, so that the method meets the aim of low-carbon environment protection for sewage recycling treatment. In addition, culturing microalgae in wastewater can produce high-value components including proteins, carotenes, astaxanthin, polyunsaturated fatty acids, and phycocyanin at lower running costs, which can be used in animal feed to improve the quality of farm and pasture products. Therefore, microalgae-based cultivation wastewater recycling sustainable treatment technology is gradually becoming a focus of attention. Nitrogen plays a key role in protein synthesis and determines the nutritional value of the harvested biomass in animal feed, so microalgae nitrogen recovery is important for recycling of aquaculture wastewater. However, nitrogen recovery in microalgae-based wastewater reclamation treatments is limited by several problems, including long treatment cycles, ammonia toxicity, and low nitrogen recovery. Firstly, the microalgae-based cultivation wastewater recycling treatment has a long operation period (14-20 days), so that the total investment and the operation cost are increased, and bacterial pollution is easy to cause. Therefore, in industrial application, conventional technologies with shorter treatment cycle than microalgae technology, such as sequencing batch reactor activated sludge process and anaerobic-anoxic technology, are widely used in the recycling treatment of aquaculture wastewater. However, the large amount of sludge produced by these conventional techniques requires further treatment and it is difficult to recover high-value components. On the other hand, the high-concentration ammonia nitrogen in the culture wastewater can increase oxidative stress in cells, prevent photosynthesis and even cause microalgae culture failure, thereby restricting the growth of algae cells. In order to control ammonia toxicity, fresh water dilution or ammonia stripping has been widely used for pretreatment of aquaculture wastewater. However, the high fresh water consumption due to dilution of wastewater and the nitrogen loss due to ammonia stripping do not meet the recycling economy concept. In addition, microalgae cultivation for wastewater recycling treatment mainly focuses on denitrification efficiency, but ignores the recovery ratio of nitrogen in wastewater to microbial biomass. Although the removal rates of TAN, TN, COD and TP in pretreatment of pig manure by using chlorella culture reach 86.80%, 86.64%, 84.99% and 100%, respectively, the nitrogen assimilation ratio of microalgae is not clear, and the volatilization loss of ammonia nitrogen caused by the rise of pH in the culture process is still quite large. In addition, volatilization of ammonia gas increases the carbon-nitrogen ratio, induces lipid rather than protein, and is thus unfavorable for use in feed. Thus, the process of nitrogen migration from wastewater to microbial biomass in microalgae-based cultivation wastewater reclamation treatments should be well understood and improved to increase protein content in the microalgae. The invention comprises the following steps: In order to overcome the problems in the prior art, the invention provides a method for treating high ammonia nitrogen wastewater and recycling the wastewater, which can treat the culture wastewater with h