CN101817592B - Comprehensive organism repairing method of eutrophication seawater cage culture zone - Google Patents

Abstract

A comprehensive bioremediation method for eutrophic seawater cage culture areas, characterized in that immobilized microorganisms, macroalgae and filter-feeding shellfish are used as joint restoration organisms, and macroalgae are suspended and raised on the upper part of the water body of the net cage culture area, quickly The filter-feeding shellfish that absorb and transform the inorganic nitrogen and phosphorus eutrophication substances in the water body are placed at the bottom of the breeding area, and the immobilized microorganisms that can partially deposit on the bottom surface of the farm are placed in the breeding water body, and strengthened by oxidation and nitrification. Degradation of organic matter and nitrification rate of nitrogen in water or sediment. The characteristics of the present invention are mainly reflected in the following two aspects: 1. Construct a comprehensive bioremediation method with macroalgae, filter-feeding shellfish and immobilized nitrifying bacteria as the main organisms, which can be expected to eliminate eutrophication substances in water bodies and substrates simultaneously and organic pollutants; 2. While eliminating pollutants, obtaining macroalgae and filter-feeding shellfish with high economic value has good environmental and economic benefits.

Description

Comprehensive bioremediation method for eutrophic seawater cage culture area

technical field

The invention belongs to the technical field of bioremediation in eutrophic sea areas, and in particular relates to a comprehensive bioremediation method for eutrophic seawater cage culture areas.

Background technique

Cage aquaculture is a representative way of high-density and intensive development of my country's marine aquaculture industry. While greatly improving the aquaculture capacity and economic benefits, it also brings serious environmental problems, such as a large amount of aquaculture animal bait produced during the aquaculture process. , excrement and other organic pollutants, as well as aquaculture wastewater containing high concentrations of nitrogen, phosphorus and other eutrophic substances, have seriously polluted the aquaculture sea area. my country's aquaculture industry continues to develop, and the degree of eutrophication in coastal waters is expanding and aggravating, which has a serious impact on the marine ecological environment. Therefore, it has become an important research topic to develop and research economical and effective cage culture environmental pollution control technology, effectively reduce eutrophication and organic matter content, and restore the comprehensive function of water body.

Bioremediation is a spontaneous or controlled process that uses organisms to absorb, metabolize, and degrade environmental pollutants to eliminate environmental pollution and restore ecology. It not only has significant advantages such as high efficiency, low cost, and no secondary pollution. , and can be carried out simultaneously with breeding production or after breeding, and has strong operability, so it has a good application prospect in the aspect of pollution control of breeding environment.

Large seaweed releases oxygen while absorbing eutrophication substances such as nitrogen and phosphorus, effectively improving the ecological quality of the breeding environment, and has the characteristics of fast growth, extensive cultivation, and low cost. It has been used as a restoration organism to remove eutrophication in the breeding environment Material aspects show good application prospects (Lin Zhenxian et al., 2006). Many scholars at home and abroad have systematically studied the restoration effects of various large seaweeds such as kelp, laver, Gracilaria chrysanthemum, Asparagus, and Gracilaria on eutrophic aquaculture environments, and discussed the effects of eutrophication in mariculture. Bioremediation strategy and mechanism (Liu Jingwen et al., 2001; Xu Zhongneng et al., 2002; Xu Yongjian et al., 2004). At the same time, large seaweed is widely used in the comprehensive breeding system of fish, shrimp and shellfish to effectively absorb and utilize eutrophication substances such as nitrogen and phosphorus in the breeding environment, and at the same time increase the dissolved oxygen content of the water body and adjust the pH value of the water body , while bioremediating the breeding environment, improve the economic output of the breeding system (Wang Jiqiao et al., 2001; Qu Keming et al., 2006; Troell et al., 1999).

There are also reports on the use of photosynthetic bacteria, bacillus, nitrifying bacteria and other microbial agents to repair and improve the environment of aquaculture water and sediment (Luo Yongsheng et al., 2006; Li Zhuojia et al., 1998; Yang Yingying et al., 2003). Wang Yanbo et al. (2005) reported the use of highly active bioremediation agents to improve the water quality of Penaeus vannamei ponds in the middle and late stages of culture. The bioremediation agents included photosynthetic bacteria, bacillus, yeast, nitrifying bacteria, and denitrifying bacteria. and actinomycetes and other 6 kinds of beneficial bacteria. The results show that the bioremediation agent can effectively improve the eutrophication state in the aquaculture water, increase the dissolved oxygen content in the water, effectively adjust the pH value of the water, and improve the transparency of the water. Yuan Youxian et al. (Patent Publication No.: 1340462A) disclose a method for degrading or transforming organic pollutants in aquaculture ponds and restoring the aquaculture environment by using wide-temperature, wide-salt Bacillus subtilis (Bacillus subtilis), which is useful for removing organic pollutants at the bottom of shrimp ponds. works well.

Although some achievements have been made in the research on bioremediation technology of eutrophication in seawater cage culture areas. However, the existing technologies still cannot provide effective methods and implementable overall solutions for the treatment of polluted water bodies. Water and sediment are two inseparable media that constitute the aquaculture environment, and their environmental quality often affects and restricts each other. The bait debris left in the breeding process and the feces produced by farmed animals will continue to deposit in the bottom mud and become an important source of bottom mud pollution; and there is a strong material exchange between the bottom water body and the surface bottom mud. Pollutants deposited in the sediment will re-enter the water body, resulting in secondary pollution of the water body. However, the existing research content often only focuses on the improvement of the environmental quality of one of the media, or the water body, or the sediment. In order to fundamentally reduce the eutrophication and organic pollution of the aquaculture environment and realize the sustainable and healthy development of the aquaculture environment, it is necessary to use a comprehensive restoration method to realize the simultaneous removal of organic eutrophication and organic pollution in water bodies and sediments. See reports on this.

Contents of the invention

The purpose of the present invention is to provide a comprehensive bioremediation method for eutrophic seawater cage culture area, which can meet the above-mentioned needs of the prior art.

A comprehensive bioremediation method for a eutrophic seawater cage culture area, characterized in that immobilized microorganisms, macroalgae and filter-feeding shellfish are used as joint restoration organisms, and the macroalgae is suspended and raised on the upper part of the water body in the net cage culture area. The filter-feeding shellfish that quickly absorb and transform inorganic nitrogen and phosphorus eutrophication substances in the water body are placed at the bottom of the breeding area, and the immobilized microorganisms that can partially deposit on the bottom surface of the breeding area are placed in the breeding water body, through oxidation and nitrification. Strengthen the degradation of organic matter and the nitrification rate of nitrogen in water or sediment.

The characteristics of the present invention are mainly reflected in the following two aspects: (1) Constructing a comprehensive bioremediation method with macroalgae, filter-feeding shellfish and immobilized microorganisms as the main organisms, which can be expected to eliminate eutrophication substances in water bodies and substrates simultaneously and organic pollutants; (2) while eliminating pollutants, obtaining macroalgae and filter-feeding shellfish with high economic value has good environmental and economic benefits.

Detailed ways

In the present invention, immobilized microorganisms, large seaweeds and filter-feeding shellfish are used as combined restoration organisms, and the large seaweeds are suspended and raised on the upper part of the water body in the breeding area, and the filter-feeding shellfish rapidly absorbs and transforms inorganic nitrogen and phosphorus eutrophication substances in the water body It is placed at the bottom of the breeding area to strengthen the absorption and transformation of organic debris and eutrophication mainly through filter feeding and biological deposition; Nitrification enhances the degradation of organic matter and the nitrification rate of nitrogen in water or sediment.

The large seaweed mentioned in the present invention is kelp, seaweed, Gracilaria twigs, asparagus, Ulva or carrageen, which can be wild species collected in coastal waters, or picked in artificial farms. The feeding density is 0.5~5.0kg/m ³ . The filter-feeding shellfish are mussels, scallops, oysters, and Philippine clams, which can be collected in the bottom mud of coastal waters or in artificial farms, and the feeding density is 20-200 shells/m ³ . The immobilized microorganisms are enriched and domesticated from long-term eutrophication and organic matter-polluted bottom mud, including photosynthetic bacteria, bacillus, subdigestive bacteria and nitrifying bacteria, mixed in an equal weight ratio, and the effective number of bacterial cells is 1.0×10 ⁷ cells/g, the dosage is 0.2-2.0kg/m ³ ; the method of immobilization of microorganisms is as follows: soak the 100-200 mesh immobilized carrier with 5% hydrochloric acid and 5% sodium hydroxide in turn After 2 hours, rinse with distilled water until neutral; after high-temperature dry heat sterilization, add 2-5L of mixed bacterial agent fermentation broth per kilogram of immobilized carrier, and freeze-dry to obtain the immobilized microbial repair bacterial agent. The immobilization carrier includes diatomaceous earth, kaolin, zeolite and the like.

Example 1

In the prawn breeding base of Ocean University of China, 5.0Kg asparagus was suspended and raised in a 1m (length) × 1m (width) × 1.5m (deep) cage, and 200 scallops were added to the bottom of the cage ( Chlamys fareri), add 2.0Kg of immobilized microorganisms obtained by mixing photosynthetic bacteria, bacillus, subdigestive bacteria and nitrifying bacteria in equal weight ratios in the net cage water body. Regular monitoring of various water quality and sediment indicators. The water quality and mud quality monitoring indicators of each bioremediation system on the 4th day are shown in Table 1. Among them, the control group is a treatment system without adding any remediation organisms. For the control group without remediation, the comprehensive environmental quality of water body and sediment is poor, both exceeding the national Class IV seawater quality and Class III marine sediment quality standards. After 4 days of restoration, compared with the control group, the inorganic nitrogen (DIN) and phosphate (PO ₄ -P) nutrients in the water body that only suspended the large seaweed asparagus significantly decreased by 68.6% and 76.9%, respectively, and the dissolved oxygen content (DO) increased by 137.5%, suspended particulate matter (SS) and chemical oxygen demand (COD) decreased by 32.9% and 12.0% respectively, but other water quality and sediment indicators did not improve significantly; for the system only adding immobilized microorganisms, Although water quality and sediment indicators have improved to some extent, DIN, PO ₄ -P, COD and SS decreased by 46.6%, 48.3%, 35.8% and 51.8% respectively, DO increased by 70.0%, and total organic carbon in sediment (TOC) and dissolved organic phosphorus (DOP) in interstitial water also decreased by 23.2% and 25.4% respectively, but the culture environment as a whole has not been improved significantly; The sediment indicators have all improved significantly, among which DIN, PO ₄ -P, COD and SS in the water body decreased by 79.1%, 77.1%, 67.9% and 88.1% respectively, DO increased by 93.7%, TOC in the sediment and dissolved organic nitrogen in interstitial water (DON) and DOP were reduced by 54.6%, 77.6% and 79.3% respectively. All indicators fully reached the II standard, and some indicators reached the I standard. The quality of the aquaculture environment was improved in an all-round way to meet the water quality requirements of mariculture.

Table 1 Monitoring indicators of water quality and mud quality on the fourth day of comprehensive restoration of immobilized microorganisms-filter-feeding shellfish-macroalgae in the culture environment of shrimp

Example 2

In the turbot breeding base of Ocean University of China, 0.5Kg laver was suspended in a 1m (length) × 1m (width) × 1.5m (depth) cage, and 20 Pacific oysters (Crassostrea gigas) were added to the bottom of the cage. Add 0.2Kg of immobilized microorganisms obtained by mixing photosynthetic bacteria, bacillus, subdigestive bacteria and nitrifying bacteria in equal weight proportions into the water body of the tank. Regular monitoring of various water quality and sediment indicators. The water quality and mud quality monitoring indicators of each bioremediation system are shown in Table 2. Among them, the control group is the treatment system without adding any restoration organisms. Similar to Example 1, in the control group that has not been repaired, the comprehensive environmental quality of the water body and sediment is poor, and the DIN\, PO ₄ -P and COD in the water body all exceed the national IV seawater quality standard, and the TOC exceeds the national Class III marine sediment quality standard; and the single use of large seaweed laver or immobilized bacterial agents can only improve part of the water quality or bottom quality indicators, and partially improve the quality of the turbot breeding environment; only the combined use of immobilized bacterial agents- The restoration system of filter-feeding shellfish-large seaweed, all kinds of water quality and sediment indicators can fully meet the standards, and the breeding environment can be completely restored.

Table 2 Monitoring indicators of water quality and mud quality on the 4th day of comprehensive restoration of immobilized microorganisms-filter-feeding shellfish-macroalgae

Claims (3)

1. the comprehensive organism repairing method of an eutrophication seawater cage culture zone; It is characterized in that repairing biology for uniting with immobilized microorganism, kelp and filter-feeding shellfish; Photosynthetic bacterium, genus bacillus, nitrite bacteria and nitrobacteria that described immobilized microorganism is obtained by enrichment in the bed mud that receives eutrophication and organic pollution for a long time and domestication, the effective quantity of mycetocyte is 1.0 * 10 ⁷Individual/g, adding quantity is 0.2～2.0kg/m ³During immobilization, 100～200 order fixation supports are respectively soaked 2h with the sodium hydroxide of 5% hydrochloric acid and 5% successively after, distilled water flushing is to neutral; Behind the high temperature dry sterilization; The per kilogram fixation support adds 2～5L mix bacterium agent fermented liquid, after the lyophilize, promptly obtains immobilized mikrobe remediation microbial inoculum; Described fixation support is zeyssatite, kaolin or zeolite; During reparation; Kelp hangs the water body top of supporting in the culture zone; Inorganic nitrogen, phosphorus eutrophication material in rapid absorption and the conversion water body, the filter-feeding shellfish is invested in the bottom, culture zone, and immobilized microorganism is invested in the aquaculture water; Part deposits to substrate top layer, culture zone, through the rate of nitrification of organic degraded and nitrogen in oxygenizement and nitrification reinforcement water body or the bed mud.

2. the comprehensive organism repairing method of eutrophication seawater cage culture zone as claimed in claim 1; It is characterized in that described kelp is sea-tangle, laver, withe fragrant plant mentioned in ancient texts, Thallus Gracilariae, sea lettuce or chondrus ocellatus Holmes; Above-mentioned kelp is the wild species that are collected in immediate offshore area; Or pluck and adopt in propagating the field artificially, adding density is 0.5～5.0kg/m ³

3. the comprehensive organism repairing method of eutrophication seawater cage culture zone as claimed in claim 1; It is characterized in that said filter-feeding shellfish is mussel, scallop, oyster or philippine clam whelp; Above-mentioned filter-feeding shellfish collection is in the immediate offshore area bed mud; Or be collected in and propagate the field artificially, adding density is 20～200/m ³