The Mechanism Of Microalgal Remediation And Pollution Migration Model Of Heavy Metals In Huangshaping Mining Karst Groundwater

This study aimed to analyze and evaluate pollution in mining Karst areas groundwater in Huangshaping,China,Hunan Province.This study examines the pollution propagation model and the bioremediation of the pollution employing Arthrospira platensis and Chlorella sp.for absorption and bioaccumulation,respectively.The research was conducted by data collection and analysis,groundwater environmental assessment grading and simulation modeling,and microalgae culture capable of producing algal biomass.This study mainly used the FEFLOW software to analyze simulation modeling represented by the Mathematical model,diffusion model dispersion,and 3-D model of Darsy’s law.The negative impacts of pollutants in mining karst groundwater necessitated implementing environmental mitigation measures such as a pollution monitoring program,grid split,geological model,and groundwater seepage modeling to evaluate and control the spread of groundwater pollution.The frequency of water monitoring was three times a month,and the parameters tested included Temperature,p H,COD,SO4,Cu,Mn,Fe,Zn,Pb,and other elements in the study area.Huangshaping is home-based to various pollution sources,including domestic sewage wastewater,industrial sewage wastewater,gushing water,industrial sewage sites producing,processing waste,tailings wastewater,rainwater,and other sources.These mining pollutants have negative consequences and impact the geological environment and groundwater quality,as evidenced by the poor circulation of underground water,the alteration of aquifer water tables,and the severe damage to natural geological formations.During the 50 years since the start of the exploitation project,the speed of pollution dispersion has increased dramatically.The enormous migratory distance was 40.7 meters 50 years ago,95.2 meters 30 years ago,and 99.5meters today.The existing mining wastewater treatment plant has been purifying approximately 7,706 m3/d of wastewater,indicating that it has had little impact on groundwater.On the other hand,lead mine tailings are incredibly prone to contamination.Groundwater wastewater treatment with green microalgae had a Suspended Solids removal rate of up to 80%and a metal removal efficiency of over 50%to remove suspended solids and metals from the wastewater.The reuse of mining wastewater using hydride water,composed of 50 percent fresh water and 50 percent mine wastewater,was employed for food production to preserve the public health of the villagers living in the vicinity of the exploration site.Nearly half of the crop yield was attributed to salt.However,there was no evidence of heavy metals in plants or soil.The removal of heavy metals from wastewater by biosorbent has the following effects:zinc adsorbed has dropped from 4.08 to 2.1216mg/g;Iron has decreased from 6.03 to0.6mg/g;copper has reduced from 5.02 to 0.75mg/g,and lead has declined from 7.04 to0.98mg/g.Sulfates（SO4）removal efficiency was 93%,the iron removal efficiency was100%,the lead removal efficiency was 95%,the zinc removal efficiency was 52%.The copper removal efficiency was 94%when p H was measured from 4.5 to 7.0 for Chlorella sp.and 5 to 9 for Arthrospira platensis.Batch Culture and semi-bioreactor culture performed the experimental design.Minitab was used to run statistical analyses on the data collected.The following conditions were used in the microalgae culture:A temperature range of 25o C to 35o C has been established.p H ranged from 4.5 to 7.5,the Light was set to 1000Lux to2000Lux for 12 hours each day and night,and turbidity was 25-40 NTU.Sorbent concentration（5 to 60mg/l）impacted biosorption and contact time（60min to 240mn）for heavy metals removal.Both the Arthrospira platensis and Chlorella sp.strains of algae were cultivated by growing on a medium with an increasing concentration of heavy metals.The microalgae culture seeds underwent a lengthy growth cycle that could be lengthened if necessary and cultured for twenty to thirty days.A study was conducted to determine the treatment capability of wastewater samples collected from industrial wastewater to evaluate the growth of microalgae Chlorella sp.The production of microalgae benefits from a nutrient found in wastewater.Single-celled green algal Chlorella sp.has a photosynthetic efficiency of 6 to 7.1%and could be used as a bioenergy source.From 25.6 percent to 97.20 percent of the heavy metals were removed effectively.Each nutrient form’s removal rate increased as long as the system was exposed to varying light levels.Total nitrogen is 89.1 percent,phosphorus is 80.9,and the chemical oxygen demand（COD）is 90.8 percent.Ammonia is 93.9%.At temperatures ranging from 15°C to 35°C,Chlorella sp.produces significant biomass,with a mean temperature of 22°C.Three distinct Pluronic concentrations of 18,20,and 22 weight percent were employed in the TAPP media to grow microalgal.A typical well-mixed TAP medium culture was used as a control.Jellification of the supernatant was achieved by raising the Temperature and scraping off the microalgae flocs from the surface of TAPP.The growth of Arthrospira platensis under different conditions such as 25^oC to35^oC of Temperature,1000Lux to 2000Lux of light intensity,1000M of each heavy metals concentration and using various nutrient sources were assessed to determine algal potentiality on biosorption removal of heavy metals(Zn²⁺,Cu²⁺,Pb²⁺,Fe²⁺)from mining effluent is accomplished through bioremediation.Arthrospira platensis is a form of microalgae that have evolved to cope with micronutrients’high alkalinity and toxic metals（Pb）.Ammonium nitrate（NH₄-NO₃）is a more effective nitrogen source than urea.When cells were exposed to a light source with a light intensity of 2000Lux,their productivity,protein content,and growth rate increased significantly.Despite the low light intensity,it was possible to get high chlorophyll and nitrogen conversions and removals from the samples,ranging from 1000Lux to 1400Lux.Within 24 hours,ammonium,total nitrogen,total phosphorus,and COD were eliminated at 95.18 percent,60.49 percent,90.92 percent,and 61.80 percent,respectively,from the water.The number of nutrients consumed and the type of medium nitrogen used impact the chlorophyll concentration during the cultivation period.Additionally,at 2000 lux,the growth rate and productivity cell were high,but Chlorophyll production and Nitrogen cell-conversion factor was lower.At low light intensity（1000Lux）,Chlorophyll production and Nitrogen cell-conversion factor were high,and this is due to the chloroplast membrane working properly stable Light1000Lux to 1800Lux.The photosynthesis efficiency and lipid&protein biomass production are high.This means that Protein biomass content was low,compared to the biosorption is high.The nitrogen-to-biomass conversion factor YX/N declined as the dilution rate value increased.Culture grown using ammonium nitrate performed significantly better than that produced the use of urea as a source of nitrogen.Cells grown in urea had a smaller average diameter than cells produced in ammonium nitrate.p H 6.5 was used for the elimination of heavy metals.The material’s sorbent content,p H,and contact time influenced the biosorption of heavy metals from wastewater.Zinc adsorption is reduced in multi-metal n culture systems compared to single-metal ones.Because Arthrospira platensis biomass was shown to remove 50%of zinc from wastewater,increasing concentrations of other metal ions in the wastewater does not affect zinc removal.The current study removed zinc ions from mining effluent to 52 percent.Arthrospira platensis and Chlorella sp.were grown on the increasing concentration of Pb.Chlorella sp.has a high Pb（II）uptake capacity at lower p H.Contrary to Arthrospira platensis has high Pb（II）uptake at p H 5-6 due to Chlorella sp.sorption being suitable in lower p H.Arthrospira platensis has a negative charge on the cell surface when low p H.Adsorption of the metal increased with increasing p H.The high bioconcentration factor suggests that Arthrospira platensis and Chlorella sp.can treat contaminated wastewater with a high Pb concentration.By increasing the Pb concentration from 25μM to 100μM,the biomass reduced from 0.5 to 0.1 dw for Chlorella sp.and 0.42 to 0.05 dw for Arthrospira platensis over a four-day incubation period.After two days,the bioconcentration factor increased from 1832,1253,and 1237but reduced gradually until the 10th day to 1250,950,and 600 for 100,50,and 25μM of Pb,respectively.The sorption generally increased with increasing sorbent dosage sorption from 86%to 90%of Pb（II）when the absorbent dosage has increased from 0.5to 6 g/L.The maximal biosorption effectiveness required 5 to 240mn,and the solution’s equilibrium was 60 minutes.Pb removal from model solution and wastewater was 3.71mg/g,corresponding to a 73%reduction.The removal efficiency was rapid within the first 20mn but stable afterward.The maximum time required for Pb（II）removal remained equal to the end of the experiment.