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In the turpentine production process, the wastewater generated from the washing and clarification of rosin is the main source of pollution in rosin processing plants. Generally speaking, this wastewater is of the organic, toxic type with a high pollution load. Domestic 2088 level transmitter: Recovery control and solution design for rosin processing wastewater. Forestry chemical enterprises that produce rosin resin intermediates generate high-concentration organic wastewater with complex compositions containing large amounts of rosin, turpentine, and other substances, and this wastewater has poor biodegradability. In light of these characteristics, this project adopts a treatment process of \"flocculation reaction sedimentation → flocculation reaction flotation → filtration\". After 4 months of debugging, adjustments, and operation, it passed the completion acceptance test. The monitoring results showed that the effluent fully met the pre-established quality requirements for recycled water, achieving zero discharge. Domestic 2088 level transmitter: Recovery control and scheme design for rosin processing wastewater. The commissioning phase lasted three and a half months; the water temperature during the flocculation reaction was between 35 and 45°C. This commissioning process included testing of the equipment as well as adjustment of the process parameters. During the trial operation of the equipment, it was found that the precipitated rosin was blocking the wastewater delivery pipes; therefore, the wastewater pretreatment system was modified by adding a set of steel structure equipment for pre-sedimentation using NaOH, which resolved the wastewater delivery issue. Process parameter tuning mainly involves adjusting the dosage of chemicals and the volume of air-stirred water. The preparation concentrations are as follows: Ca(OH)2 is used as a supersaturated emulsion, Al2(SO4)3 is used as a 10% solution, and PAM is used as a 1‰ solution. Chemical dosing is carried out using a pH monitor in conjunction with a metering pump. The controlled pH range for the reaction and the corresponding dosage of chemicals are as follows: in the flocculation reaction sedimentation tank, the pH range is 9.0–10.5, with a Ca(OH)2 dosage of 4 kg/h; in the flocculation reaction flotation tank, the pH range is 6.6–7.2, with a Al2(SO4)3 dosage of 1.6 kg/h and a PAM dosage of 0.054 kg/h. The ratio of dissolved air water is R=30%, and the pressure is 0.3～0.4 Mpa. 2. Reduce the pollution of water bodies and soil by harmful substances. Urban sewage contains pathogenic bacteria, harmful organisms such as viruses and parasite eggs, various heavy metals, as well as recalcitrant organic chemicals. If these substances are discharged directly into surface water systems along with wastewater, they not only contaminate surface water systems directly but also pollute groundwater systems and soil through infiltration, causing damage to the natural environment; furthermore, they can pose a threat to human health via food derived from aquatic plants and animals. Domestic 2088 level transmitters: Recovery control and design solutions for rosin processing wastewater. There are nitrogen-containing organic wastes such as urea wastewater and *** wastewater; these types of wastewater are difficult to degrade and pose challenges in terms of treatment. If discharged without proper treatment, they can cause severe environmental pollution. Treating nitrogen-containing organic wastes is one of the important tasks in environmental protection, and supercritical water oxidation technology can provide an effective solution to this wastewater treatment problem. During supercritical water oxidation, nitrogen-containing organic compounds produce ammonia, which, under the action of oxidants, forms small molecular compounds such as NO and NO2. Under high-temperature conditions of 822 K, after a reaction time of 3 minutes, the removal rate of organic nitrogen in urea wastewater can reach 95% ； ***Under high temperatures of 390°C, after a reaction time of 10 minutes, the removal rate reaches 99%. Domestic 2088 level transmitter: Recovery control and scheme design for rosin processing wastewater. 3. Harmonizing the relationship between human development and ecosystem balance. Human development has caused significant damage to the natural environment since the Industrial Revolution, and issues such as the greenhouse effect, soil desertification, and the near-exhaustion of energy sources pose serious threats to the future living conditions of humanity. Establishing a harmonious relationship between human development and the natural ecological environment is a topic of widespread concern at present. The green development approach proposed in our country today aims to reduce the flow of harmful substances resulting from human activities into ecosystems, as well as to conserve water resources and non-renewable energy sources. The construction of urban sewage treatment and reuse systems is precisely a requirement of green development. Regarding the volume and quality of wastewater, there should be 2 production lines with an annual capacity of 100,000 tons of maleic rosin resin intermediates; these lines produce an average of 100 tons of maleic rosin per day. The wastewater generation rate per unit of product is approximately 1.6 m3, resulting in 160 m3 of wastewater generated daily. The process is designed to operate continuously for 24 hours, meaning the treatment capacity is 6.7 m3/h. The wastewater entering the wastewater treatment system includes wastewater from production processes, wastewater from workshop cleaning, and wastewater from rosin maintenance. The drainage volume from the production section is approximately 1.3 m3 per ton of rosin, accounting for 80% of the total wastewater volume; its composition is complex and the pollutant concentrations are high. The indicators of mixed wastewater such as CODcr, SS, oils and fats, and Fe2+ are all high, with a B/C value of less than 0.1. Taking into account factors such as the feasibility of the treatment process, treatment costs, and requirements for the quality of water used in production, the factory requires that all treated wastewater be reused in production. Domestic 2088 level transmitter: Recovery control and scheme design for rosin processing wastewater. 1. Pretreatment: Pretreatment includes sieving, sedimentation, oil separation, and alkaline pre-sedimentation. The temperature of the wastewater discharged from production is around 80°C; at this temperature, it contains a large amount of SS, which consists mainly of debris such as bark, wood chips, sand, and stones brought in from the raw materials, and all of these can be trapped by the sieve. As the water temperature drops, large amounts of resin and turpentine are also precipitated and accumulated, which can be collected, recovered, and reused through sedimentation and oil separation facilities. Given that the treatment station is located far from the wastewater discharge outlet in the workshop, resin may still precipitate during transportation and cause pipeline blockages; therefore, a pre-sedimentation facility equipped with NaOH was installed during the renovation to minimize the risk of pipeline blockages. 2. When the wastewater enters the regulation tank, its temperature is generally between 55 and 60°C; a blower is used to stir the water and cool it down, and after 12 hours the temperature can be reduced to 40–45°C, which ensures better results in the subsequent physical and chemical treatment processes. 3. Sedimentation, air flotation, and filtration: To keep the process as simple and compact as possible and to facilitate operation, the design of the equipment and the selection of materials have been optimized as follows: (1) The flocculation reaction zone adopts a perforated swirl format and is built together with the sedimentation zone or the air flotation zone. (2) Slotted plate sedimentation is selected for the precipitation form, taking advantage of the high density and easy sedimentation of the flocs formed after adding Ca(OH)2. (3) For the air dissolution method, a gas-liquid mixing pump is used in place of the conventional combination of an air compressor, a dissolved air tank, and a dissolved air pump; meanwhile, fiber balls are used as the filter media in the filtration tank, which allow for direct backwashing, eliminating the need for gas-based backwashing facilities.