10T/D Tin Plating Wastewater Treatment Project for Oulai New Materials

12 Aug, 2026 2:55pm

10T/D Tin Plating Wastewater Treatment Project for Oulai New Materials

WTEYA successfully delivered a 10T/D tin plating wastewater treatment system for Guangdong Oulai Hi-Tech Material Co., Ltd., utilizing a sequential batch physicochemical treatment system combined with AD (Anaerobic Digestion) and MBR (Membrane Bioreactor) technology to achieve compliant discharge and water reuse.

🤝 Project Overview

Guangdong Oulai Hi-Tech Material Co., Ltd. is a leading manufacturer of high-performance electronic materials, specializing in tin-plated products and surface treatment processes. The company's production generates tin-bearing wastewater containing heavy metals, complexing agents, and organic contaminants that require specialized treatment before discharge.

Item	Detail
Client	Guangdong Oulai Hi-Tech Material Co., Ltd.
Project	10T/D Tin Plating Wastewater Treatment
Capacity	10 tons per day
Treatment Goal	Compliant discharge + partial reuse
Process	Sequential Batch Physicochemical + AD + MBR

💧 Tin Plating Wastewater Characteristics

Tin plating wastewater from electronic material manufacturing presents unique treatment challenges due to its complex composition:

Tin (Sn) compounds — Stannous and stannic ions requiring specialized precipitation and coagulation
Heavy metals — Copper, nickel, and lead traces from plating bath carryover
Complexing agents — EDTA, citrate, and tartrate that bind metal ions and resist conventional precipitation
Organic contaminants — Surfactants, brighteners, and wetting agents from plating additives
High COD — Chemical oxygen demand from organic additives and solvents
Variable pH — Acidic and alkaline waste streams requiring careful pH adjustment
Low biodegradability — BOD/COD ratio often below 0.2, requiring advanced oxidation as pre-treatment

Conventional treatment methods often fail to meet discharge standards for tin-bearing complex wastewater. WTEYA's integrated approach combines the strengths of physicochemical separation, biological degradation, and membrane filtration to achieve reliable results.

⚡ Treatment Process: Sequential Batch Physicochemical + AD + MBR

WTEYA designed a three-stage treatment system specifically tailored for Oulai's tin plating wastewater:

Stage 1: Sequential Batch Physicochemical Treatment System

The sequential batch physicochemical reactor operates in a time-based cycle rather than a continuous flow format, offering superior flexibility for variable wastewater loads:

pH Adjustment — Precise dosing of acid/alkali to break metal-complex bonds and optimize precipitation conditions
De-complexing — Oxidative breaking of EDTA and citrate complexes using sodium hypochlorite and Fenton's reagent, releasing free metal ions
Coagulation & Flocculation — PAC (polyaluminum chloride) and PAM (polyacrylamide) dosing to form dense flocs capturing tin and heavy metal hydroxides
Sedimentation — Batch settling with sludge recycling to reduce chemical consumption
Sequential Operation — Fill → React → Settle → Decant → Idle cycles ensure complete reaction and high removal efficiency

Key advantages of the batch system include: 40% smaller footprint compared to continuous flow systems, precise reaction control, ability to handle shock loads, and reduced chemical consumption through optimized dosing algorithms.

Stage 2: AD (Anaerobic Digestion) Biological Treatment

Following physicochemical pre-treatment, the wastewater enters an anaerobic digestion reactor to degrade residual organic contaminants:

Hydrolysis & Acidogenesis — Complex organics (surfactants, brighteners) are broken down into volatile fatty acids by acidogenic bacteria
Methanogenesis — Methanogenic archaea convert VFAs to biogas (methane + CO₂), reducing COD by 50–70%
Granular Sludge — UASB-type granular biomass provides high biomass concentration and resistance to toxic compounds
Biogas Recovery — Generated methane can be captured for energy recovery, reducing operational costs

The AD stage is particularly effective for the high-COD, low-biodegradability wastewater from tin plating, as the anaerobic environment can degrade complex organics that aerobic processes struggle with. Typical COD removal: 50–70%, with biogas yield of 0.3–0.5 m³ per kg COD removed.

Stage 3: MBR (Membrane Bioreactor) Polishing

The final treatment stage uses a Membrane Bioreactor to achieve high-quality effluent suitable for discharge or reuse:

Aerobic Biodegradation — Activated sludge degrades residual dissolved organics to achieve COD < 50 mg/L
Membrane Filtration — PVDF hollow fiber membranes (0.1 μm pore size) completely retain biomass, producing crystal-clear permeate
High MLSS Operation — Mixed liquor suspended solids maintained at 8,000–12,000 mg/L, enabling compact tank design and stable performance
Nutrient Removal — Simultaneous nitrification-denitrification within the MBR tank removes nitrogen and phosphorus
Sludge Reduction — Long sludge age (30–60 days) minimizes excess sludge production, reducing disposal costs

MBR effluent quality: COD < 50 mg/L, BOD < 10 mg/L, SS ≈ 0 mg/L, turbidity < 1 NTU, meeting Class I discharge standards and suitable for partial reuse in the production line.

🏭 Technical Highlights & Innovation

Integrated Three-Stage Approach

The combination of sequential batch physicochemical treatment, anaerobic digestion, and MBR technology creates a synergistic treatment train where each stage addresses specific contaminants:

Physicochemical stage removes heavy metals (Sn, Cu, Ni) and breaks complexing agents
AD stage degrades refractory organics and reduces COD load on the MBR
MBR stage provides final polishing and complete solids removal

Sequential Batch Reactor (SBR) Advantages

Handles variable wastewater flow and concentration — ideal for batch-production facilities
No separate sedimentation tank needed — 40% smaller footprint
Real-time ORP and pH control for optimized chemical dosing
Sludge settling occurs under static conditions, ensuring excellent separation

PLC Automatic Control System

Full-process automation with Siemens S7-1200 PLC
Touch screen HMI with real-time monitoring of pH, ORP, DO, MLSS, flow rate
Remote monitoring via mobile app for unattended operation
Automatic alarm and safety interlock for abnormal conditions
Data logging and reporting for regulatory compliance

Anti-Corrosion Design

All wetted components use corrosion-resistant materials: PP/HDPE for chemical tanks, 316L stainless steel for piping and valves, and epoxy-coated carbon steel for structural frames. This ensures long service life (>nearly 20 years) in the aggressive tin plating wastewater environment.

🛡️ WTEYA — Your Trusted Wastewater Treatment Partner

WTEYA (Guangdong WTEYA Environmental Technology Co., Ltd.) has been specializing in industrial wastewater treatment for nearly 20 years. With a 30,000 m² manufacturing base, 500+ employees, and 200+ patents, WTEYA has delivered over 2,000 wastewater treatment projects across 30+ provinces in China and 30+ countries worldwide.

Our core expertise includes:

Heavy Metal Wastewater Treatment — Tin, copper, nickel, chromium, zinc, and lead removal systems
Plating & Surface Treatment Wastewater — Electroplating, anodizing, and coating wastewater solutions
MBR & Membrane Technology — MBR, UF, NF, and RO systems for water reuse and ZLD
Sequential Batch Reactor (SBR) Systems — Compact, flexible physicochemical treatment for variable loads
Zero Liquid Discharge (ZLD) — Complete wastewater recycling with MVR evaporation technology
OEM & ODM Services — Custom-designed systems built to client specifications

WTEYA's clients include leading enterprises such as CATL, BYD, Foxconn, Ganfeng Lithium, and other Fortune 500 companies. All systems are certified with ISO9001, ISO14001, and ISO45001, with equipment reliability exceeding 99%.

Frequently Asked Questions

Q: How does industrial wastewater treatment work?

A: Industrial wastewater treatment typically involves pre-treatment, membrane concentration, evaporation, and crystallization to remove contaminants and recover water.

Q: What are the benefits of wastewater recycling?

A: Benefits include reduced water costs, environmental compliance, reduced discharge fees, and improved corporate sustainability.