Treatment of Black and Odorous Water Bodies in Rivers and Lakes

For riverbeds and revetments, wherever possible natural riverbanks and riverbeds should be preserved, minimizing artificial engineering modifications. Where modification is necessary, ecological revetments should be employed; such revetments not only stabilize the riverbed but also enhance exchange between surface water and groundwater, thereby promoting the growth of aquatic and terrestrial flora and fauna and leveraging their natural purification functions. For waterways that have already been hardened, where conditions permit, cement-lined embankments should be gradually phased out. Instead, relatively low-permeability clay can be compacted and rolled to form a dense layer, upon which permeable, erosion-resistant paving bricks are laid. This approach effectively addresses substantial seepage while providing a certain degree of recharge to the groundwater, improving connectivity between surface and groundwater, and enhancing the self-purification capacity of surface water bodies.

　　 Our company primarily employs a multi-tiered, structured ecological riparian-zone infiltration and purification technology. This approach leverages natural materials such as vegetation in combination with engineered materials to construct ecological restoration systems—including buffer zones—along the riparian zone. Typically, living plant roots, stems (or branches), or entire plants are used as the primary structural elements, which are inserted or planted at specific locations and orientations within the riparian zone. Through the establishment of plant communities, the riparian zone is reinforced and stabilized, thereby mitigating the shortcomings of hardened river channels. This technology enhances stormwater retention capacity, reduces soil and water loss, effectively controls runoff pollution, and provides some degree of water-quality purification. It also promotes soil–water cycling and helps restore the ecological and landscape functions of the riparian zone.

Construction of Urban Black and Odorous Water Body Remediation Projects

　　The black, malodorous condition of river water is primarily caused by excessive pollutant loading, which disrupts the balance between oxygen supply and consumption in the water body. Under these conditions, pollutants undergo transformation, generating odorous substances such as ammonia nitrogen, hydrogen sulfide, and volatile organic acids, as well as black-colored compounds like iron and manganese sulfides.

　　The key to resolving the problem of black, malodorous urban river water lies in first achieving breakthroughs in the treatment of such water—making it clear, transparent, colorless, and odorless to improve the surrounding environment—and doing so swiftly. From a purely technical standpoint, energy-efficient microfiltration combined with microflocculation can deliver rapid results: once the equipment is on site, operations can commence within a week, and the treated water will immediately meet the aforementioned standards. This outcome is made possible by a comprehensive, purpose-built system specifically designed for the rapid remediation of black, malodorous rivers. The system features skid-mounted, mobile units that can be readily disassembled and relocated as needed, with modular components that allow for flexible configuration and scaling based on flow rates. One single unit can serve multiple purposes, addressing varying requirements while effectively reducing COD, suspended solids, color, odors, and total phosphorus, all while simultaneously dewatering sludge. Moreover, the equipment is fully automated and intelligent, enabling centralized management via the internet. 　

ERM stands for Ecological Remediation Microorganisms. ERM ecological restoration microorganisms are a composite microbial formulation comprising various bacilli, molds, actinomycetes, photosynthetic bacteria, and enzyme preparations. Based on this formulation, our company has achieved significant social, environmental, and economic benefits in areas such as the remediation of river and lake sediment pollution, water pollution control and ecological restoration, land pollution remediation, and soil improvement, demonstrating broad potential for widespread application and substantial value.

It is now a widely accepted consensus in the industry that no single water pollution control technology can alone shoulder the dual responsibilities of water pollution remediation and aquatic ecosystem restoration.

　　The only sustainable and effective approach to water pollution control and ecological restoration is to adopt a comprehensive, integrated technological strategy that leverages the strengths of different methods and fosters collaboration among leading technologies. ERM’s enzymatic technology for water pollution control and aquatic ecological restoration is one of the fundamental techniques in this field. It boasts excellent technical compatibility, allowing it to be seamlessly combined with various aeration technologies, aquatic-plant-based remediation methods, carrier-based approaches, point-source pollution control systems, biological manipulation strategies, and eco-friendly shoreline stabilization techniques. By addressing water quality, aquatic ecosystems, sediment, and riparian zones in a holistic manner, this integrated approach ultimately delivers a healthy ecological environment characterized by clear water, lush banks, thriving fish populations, and abundant birdlife.

　　 Core Advantages

　　1. Low project costs and simple construction

　　2. No high energy consumption; excellent treatment performance

　　3. Low maintenance costs and high biosafety

　　4. No secondary pollution; product is easy to store and transport.

　　Technical Approach

　　► Addressing Existing Stocks—Eliminating Endogenous (Sediment) Pollution

　　Eliminating endogenous pollution is both the primary focus and the greatest challenge in water pollution control—and it also serves as the starting point for our technological approach. Addressing sediment pollution, reducing sediment loads, and leveraging in-situ purification at the water bottom to drive overall water-quality improvement are key to reducing existing pollutant stocks;

　　► Reduce and eliminate – eliminate external pollution

　　Eliminating external pollution sources is a necessary measure for water pollution control. It primarily involves technical approaches such as intercepting and channeling sewage, maintaining water cleanliness, aerating the water, applying chemical agents, planting aquatic vegetation, and introducing aquatic animals.

　　Mechanism of Black and Odorous Water Body Formation

　　1. In natural water bodies, which are relatively less polluted by human activities, dissolved oxygen levels in the water and bottom sediments are generally high. Under these conditions, indigenous aerobic microorganisms decompose organic pollutants into carbon dioxide and water—substances that are colorless, odorless, and invisible.

　　2. When anthropogenic pollutants are discharged into rivers, lakes, and ponds in large quantities and over prolonged periods, substantial amounts of these pollutants become suspended in the water column and settle on the bottom sediments. Aerobic microorganisms require large amounts of dissolved oxygen to degrade these excessive pollutants; however, the rate at which oxygen diffuses into the water is far slower than the rate at which aerobic microorganisms consume oxygen. Consequently, the polluted water body and its bottom sediments remain in a state of severe hypoxia for extended periods. Under such extreme hypoxic conditions, anaerobic microorganisms assume the primary role in pollutant degradation.

　　3. The black color and foul odor are caused by sulfide formation resulting from the anaerobic decomposition of pollutants, particularly organic pollutants. Because large amounts of organic matter accumulate on the water bottom, anaerobic reactions predominantly occur in the bottom sediment.

　　The black color is caused by anaerobic sulfidation reactions that produce large amounts of black metal sulfides, such as ferrous sulfide and manganese sulfide.

　　Odor—this is caused by anaerobic sulfidation reactions that also produce large amounts of malodorous gases such as hydrogen sulfide, ammonia nitrogen, biogas, and volatile organic acids.

　　4. Therefore, to eliminate black and odorous water bodies, the first step is to select highly effective, specialized microorganisms that exert strong inhibitory effects on anaerobic microorganisms while efficiently degrading organic pollutants, thereby eliminating the black and odorous conditions in both the bottom sediment and the water column. The second step is to enhance oxygenation through aeration, increasing the dissolved oxygen levels in the water and boosting the biological activity of aerobic microorganisms. Under this dual action, the anaerobic processes in the bottom sediment and water body are gradually transformed into aerobic processes, thereby eliminating black and odorous conditions and improving water quality.

　　The Function of EPSB Engineered Bacterial Solidified Granules

　　♦ Strongly inhibits anaerobic reactions in the sediment, eliminating black and odorous conditions (deodorization within two weeks, elimination of black color within one month);

　　♦ Rapidly reduces organic pollutants in bottom sediments, achieving a reduction of more than 50% within 3–6 months;

　　♦ Degradation or mineralization of heavy metals and inorganic pollutants in sediment;

　　♦ Reduce the moisture content of sediment, increase its density, and induce sandification of the sediment;

　　♦ Prevent the release of deep-bottom-sediment pollution into the water body;

　　♦ Oxidize bottom sediments to improve dissolved oxygen levels in the water column and within the sediments;

　　♦ Potently inhibits pathogenic microorganisms such as fecal coliforms;

　　Create a suitable benthic ecological environment for benthic organisms and provide appropriate sedimentary soil conditions for aquatic plants.

　　 Applicable Conditions for EPSB Engineered-Bacteria-Immobilized Granules

　　EPSB engineered microorganisms exhibit salt–alkali tolerance and are widely applicable to the remediation of black, malodorous water bodies, water pollution control, cyanobacterial bloom management, saline–alkali intertidal zone restoration, and aquatic ecosystem rehabilitation in open water bodies such as rivers, lakes, reservoirs, and coastal waters. They demonstrate strong pollutant tolerance, can function normally under low- or anoxic conditions, and are adaptable to a broad pH range; however, when water (or sediment) temperatures fall below 10°C, EPSB engineered microorganisms enter a dormant state.

　　Main Functions of EPSB Engineered Bacterial Solidified Granules