阿里地区How to Treat Wastewater? A Detailed Analysis of Full-Process Technologies, Classified Solutions & Compliance Standards

Wastewater treatment is a systematic engineering that integrates physical, chemical and biological technologies to remove suspended solids, organic matter, nitrogen, phosphorus, heavy metals and other pollutants from water bodies, so as to make the effluent meet discharge standards or realize recycled reuse. Faced with wastewater from domestic, industrial and other sources, stable environmental compliance can only be achieved by adhering to the principles of staged treatment and classified targeted governance. This paper systematically explains how to treat wastewater, covering full-process technologies, scenario-based solutions, compliance standards and operation & maintenance essentials, providing professional reference for enterprises and engineering practices.

Wastewater is categorized into domestic wastewater and industrial wastewater by source, and differences in pollutant composition directly determine the treatment route:

Domestic wastewater: Mainly contains COD, BOD, ammonia nitrogen and total phosphorus with good biodegradability, suitable for treatment processes dominated by biological methods.

Industrial wastewater: Contains heavy metals, refractory organics, high salinity, oils and other substances, which requires targeted pre-treatment plus advanced treatment.

Core treatment principles: Conduct pre-treatment to protect equipment firstly, then biological treatment to reduce organic pollutants, followed by advanced treatment to upgrade water quality, and final solid waste disposal. The whole process shall comply with Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB 18918-2002) as well as special discharge standards of various industries.

Core goal: Remove large floating debris, regulate water volume and quality to protect subsequent treatment units.

Bar screen: Intercept large particulate impurities such as plastic bags and branches.

Grit chamber: Remove sediment and inorganic particles to reduce equipment abrasion.

Equalization tank: Balance water quality fluctuation, control pH value and mitigate shock load.

Treatment effect: Eliminate 30%-50% suspended solids and lay a solid foundation for core treatment.

Common processes: Coagulation sedimentation, dissolved air flotation, oil separation.

Add coagulants like PAC and PAM to flocculate and settle colloidal substances.

Dissolved air flotation efficiently removes emulsified oil and fine suspended solids.

Application: Pre-treatment for oily wastewater and high-SS wastewater to lower biochemical load.

This is the core link of wastewater treatment, which decomposes organic matter through microbial metabolism:

Mainstream processes: A²/O, SBR, biological contact oxidation, MBR Membrane Bioreactor.

Target removal efficiency: 80%-90% of COD and BOD, with simultaneous nitrogen and phosphorus removal.

Advantages of MBR: Membrane separation replaces secondary sedimentation tank, cutting land occupation by 30%-50%, and the effluent can be reused.

Further purification to meet high-standard discharge or reclaimed water requirements:

Filtration: Quartz sand filter, activated carbon filter, precision filter.

Membrane technologies: Ultrafiltration, nanofiltration, reverse osmosis.

Advanced oxidation: Ozonation, Fenton process, photocatalysis to degrade refractory organics.

Disinfection: Ultraviolet light, chlorine dioxide to kill pathogenic microorganisms.

The effluent can reach Grade 1 A standard and satisfy the demands of landscape replenishment and industrial reuse.

Thickening → dewatering → stabilization (anaerobic digestion / aerobic composting)

Disposal methods: Incineration for power generation, building material production, sanitary landfilling to eliminate secondary pollution.

Process route: Bar screen → equalization tank → A²/O biochemical tank → secondary sedimentation tank → disinfection → discharge

Application: Urban residential quarters, schools and office buildings, stably meeting Grade 1 A standard specified in GB 18918-2002.

Chemical / pharmaceutical wastewater: Neutralization → coagulation sedimentation → hydrolytic acidification → anaerobic treatment → aerobic treatment → advanced oxidation

Printing and dyeing wastewater: Bar screen → equalization tank → coagulation air flotation → anaerobic treatment → aerobic treatment → decolorization filtration

Food / livestock breeding wastewater: Oil separation → equalization tank → UASB anaerobic reactor → SBR aerobic tank → nitrogen and phosphorus removal

Heavy metal wastewater: Chemical precipitation → chelating adsorption → filtration to ensure heavy metal indicators up to standard.

Physical treatment: Bar screen, sedimentation, air flotation and filtration, no secondary pollution, suitable for pre-treatment.

Chemical treatment: Neutralization, coagulation, redox reaction, ion exchange, targeted removal of heavy metals and refractory substances.

Biological treatment: Combined anaerobic-anoxic-aerobic processes, low-cost degradation of organic matter, the mainstream core technology.

Advanced treatment: Membrane separation and advanced oxidation to satisfy reuse and strict discharge standards.

Comply with national standards plus industrial standards and apply for pollutant discharge permits.

Dilution discharge, concealed discharge and leakage discharge are strictly prohibited; online monitoring data shall be connected to regulatory platforms.

Conduct regular water quality inspection to ensure COD, ammonia nitrogen, total phosphorus, heavy metals and other indicators meet standards.

Clean bar screens and discharge sludge regularly to prevent blockage.

Control DO, pH and sludge concentration in biochemical tanks to maintain microbial activity.

Clean membrane modules periodically to extend service life.

Establish emergency response plans to cope with water quality fluctuations and equipment faults.

Prioritize resource utilization: Convert wastewater into reclaimed water, produce biogas / building materials from sludge to turn waste into valuable resources.

Intelligent O&M: PLC automatic control and IoT monitoring to cut costs and boost efficiency.

Low-carbon processes: Anaerobic ammonium oxidation, shortcut nitrification to reduce energy consumption and carbon emissions.

Breakthroughs in refractory wastewater treatment: New catalytic oxidation technologies and high-efficiency microbial agents to improve treatment efficiency.

There is no universal solution for wastewater treatment. The core logic is to match processes according to water quality, reduce pollutants in stages and guarantee compliance with strict standards. Only the full collaboration of pre-treatment, advanced purification, core biological treatment and sludge disposal can achieve a win-win result for environmental protection and economic benefits. Enterprises shall select suitable processes and standardize operation & management based on their own wastewater characteristics, so as to meet compliance requirements and promote the cyclic utilization of water resources.