Bacillus sp. SS15 Bioflocculant Biosurfactant Fracturing Flowback Treatment
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Solution Overview
Problem
Current methods for treating fracturing flowback fluid, such as physical and chemical processes, are costly and inefficient in removing suspended solids, COD, and hydrocarbons due to harsh environmental conditions and limited microbial activity, with existing bioflocculants showing unstable flocculation and low biodegradability.
Innovation Solution
A Bacillus sp. strain SS15 that produces both bioflocculants and biosurfactants, exhibiting high activity and stability across a wide pH, temperature, and salinity range, is used to effectively remove chroma, suspended solids, COD, and hydrocarbons from fracturing flowback fluid through flocculation and biodegradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If physical and chemical treatment processes (coagulation, air flotation, activated carbon adsorption) are used to treat fracturing flowback fluid, then treatment cost and pollutant removal capacity are improved, but treatment cost increases and secondary pollution occurs
Solution Approach 1:
The patent employs natural microbial communities and their metabolic products (enzymes, extracellular polymers) as temporary, biodegradable agents that decompose pollutants without leaving harmful residues. These biological agents are consumed or transformed during the treatment process, eliminating the need for persistent chemical additives that cause secondary pollution.
Solution Approach 2:
The patent converts the harmful effects of harsh environmental conditions (high salinity, pH extremes, toxic chemicals) that normally inhibit microbial activity into selective advantages. The microbial community adapts by producing specialized enzymes and stress-resistant extracellular polymers that function effectively under these extreme conditions, transforming the harmful environment into a condition that selects for highly efficient pollutant-degrading organisms.
2Reliability
If chemical bioflocculants such as polyacrylamide are used, then suspended solids removal is improved, but cost increases and environmental friendliness deteriorates
Solution Approach 1:
The patent replaces synthetic polyacrylamide bioflocculants with natural extracellular polymers produced by microorganisms. These biological polymers are biodegradable, cost-effective, and eliminate the environmental hazards associated with synthetic chemicals, while maintaining effective flocculation of suspended solids through natural polymer chains that bridge and aggregate particles.
Solution Approach 2:
The patent changes the chemical composition parameters of the bioflocculant from synthetic polymers to natural microbial extracellular polymers with different molecular structures. These natural polymers have varying chain lengths, functional groups, and molecular weights that adapt to different water matrices, providing effective flocculation while being environmentally benign and biodegradable.
3Object-generated harmful factors
If microbial technology is used to treat fracturing flowback fluid, then environmental friendliness and biodegradability are improved, but treatment effectiveness is limited due to unstable flocculation activity and low bioavailability
Solution Approach 1:
The patent ensures continuous and stable microbial activity by maintaining optimal environmental conditions (temperature, pH, salinity, nutrient availability) throughout the treatment process. The microbial community is sustained through continuous metabolism, producing consistent amounts of enzymes and extracellular polymers that continuously degrade pollutants and facilitate flocculation, eliminating the instability observed in previous microbial treatment attempts.
Solution Approach 2:
The patent introduces extracellular polymers as intermediary substances produced by microorganisms. These polymers mediate between the microbial cells and the pollutants, forming a stable interface that enhances contact and reaction efficiency. The extracellular polymers act as vectors that transport nutrients to microbes and facilitate the degradation of hydrophobic organic matter, thereby improving treatment effectiveness while maintaining environmental friendliness.
4Object-generated harmful factors
If microbial growth and metabolism are used to degrade pollutants, then biodegradability is improved, but microbial activity is restricted due to harsh environmental conditions (pH, salinity, toxic chemicals)
Solution Approach 1:
The patent modifies the environmental parameters (pH, temperature, salinity, nutrient composition) to match or exceed the harsh conditions found in fracturing flowback fluid. By acclimating and selecting microbial strains that can thrive under these extreme conditions, the system maintains high microbial activity and metabolic rates despite the presence of high salinity, extreme pH, and toxic chemicals, thereby achieving effective biodegradation.
Solution Approach 2:
The patent creates a composite microbial community that includes diverse species working synergistically. This composite system combines organisms with different tolerance ranges and metabolic capabilities, where some species degrade toxic chemicals while others tolerate extreme pH and salinity. The composite community produces a mix of degradation products and extracellular polymers that enhance overall treatment effectiveness under harsh conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The Bacillus sp. SS15 strain achieves significant removal of chroma (85.72%), suspended solids (94.40%), COD (84.86%), n-alkanes (49.95%), and polycyclic aromatic hydrocarbons (66.46%) with improved biodegradability and toxicity profiles compared to synthetic surfactants and chemical bioflocculants.
Implementation Method 1
The obtained Bacillus sp. SS15 has the functions of producing a bioflocculant and a biosurfactant and degrading hydrocarbons at the same time
Implementation Method 2
The surfactants produced by SS15 are phospholipids, and the critical micelle concentration is 44.37 mg/L, which can reduce the surface tension of water from 72 mN/m to 36.56 mN/m
Implementation Method 3
A biological treatment process uses microorganisms to absorb the organic substances in wastewater and decompose them into substances with lower toxicity or non-toxicity
Data Source
AI summary
The present application discloses a Bacillus sp. producing a bioflocculant and a biosurfactant. The microbial classification of the Bacillus sp. is named Bacillus sp. SS15, which has been preserved in China Center for Type Culture Collection on Mar. 29, 2021, and its preservation number is CCTCC M2021295; the 16S rRNA sequence of SS15 is shown as SEQ ID NO.1. Bacillus sp. SS15 obtained by the present application has the function of simultaneously producing a bioflocculant and a biosurfactant. The bioflocculant and biosurfactant produced by Bacillus sp. SS15 of the present application not only have high activity, but also show strong tolerance in the ranges of pH (2-12), temperature (4° C.-100° C.) and salinity (0-100 g/L). Meanwhile, they can be applied to the remediation of a fracturing flowback liquid and can effectively promote the removal of chroma, suspended solids, COD, n-alkanes and polycyclic aromatic hydrocarbons at the same time.