GONGDA ZHONGJIE GONGDA ZHONGJIE
Company

We weld the membrane, we do not relabel it

Jiangsu Zhongjie Environmental Technology Co., Ltd. designs and manufactures tubular membrane elements and the systems built around them, on one site in Jiangbei New Area, Nanjing.

Who we are

Founded 2014, in the Nanjing membrane technology park

The company was established in November 2014 and works from No. 1 Yuansi Road, in the membrane technology industrial park of the Jiangbei New Area Industrial Technology Research and Innovation Park, Nanjing. In 2020 the park designated the company one of its key cultivated enterprises — the same year it passed ISO 9001 quality management certification.

What that means for a buyer is narrower than it sounds: the membrane formulation, the welded tubular element and the assembled skid are all produced and tested here. Nothing is bought in, rebranded and shipped out. When we tell you a stream will behave in a particular way, the claim rests on trials run on our own hardware.

GONGDA ZHONGJIE site entrance, Jiangbei New Area, Nanjing
The site entrance at the membrane industrial park, Jiangbei New Area, Nanjing.
Milestones

How the company got to its present shape

2014
Founded in Nanjing, Jiangsu

Established in November 2014 as a membrane technology company, working from the Jiangbei New Area industrial technology park.

2020
Key cultivated enterprise of the membrane technology industrial park

Recognised by the park as one of the companies it supports and grows. In the same year the company passed ISO 9001 quality management certification, bringing membrane formulation, element welding and factory testing under standardised control with traceable delivery records.

2023
High-Tech Enterprise certification

Recognised as a High-Tech Enterprise under China's national certification programme, on the strength of sustained R&D investment and self-owned intellectual property — patents covering membrane material formulations, element structures and system integration.

Today
5,000 m² own production workshop

A workshop equipped with a non-woven-supported tubular membrane welding line and full-system test bays, covering the chain from membrane material to element to skid-mounted plant — with factory verification before dispatch.

Technical backing

Nanjing Tech University, membrane science research institute

The membrane research institute at Nanjing Tech University is the technical source behind the product line. That link is what makes the material formulations and the element structures possible — and what a buyer is really paying for when they choose a tubular element over a cheaper hollow-fibre bundle.

Materials

Membrane formulations

Separation layers of PVDF, PES and modified PVDF, selected against the pH, temperature and solvent exposure of the actual stream rather than a generic duty class.

Filtration rating across the range: 30–200 nm.
Elements

Element construction

Imported non-woven support with a double-layer welding process, which raises the mechanical strength of the membrane tube and its tolerance of pressure surges and backwash fatigue.

Maximum inlet pressure: 10 bar, leaving headroom for higher crossflow velocity on viscous feeds.
Systems

Process integration

A complete chain from membrane material to element to process system, so the element is specified against the plant it will sit in rather than in isolation.

Support runs from bench test, through pilot, to commissioning.
What the research link buys you

It means a feed that does not fit the catalogue can still be worked on. Formulation, pore structure and element geometry are things the company can vary, because it makes them — not things it has to source. Where the feed is genuinely out of range, we would rather say so and point you elsewhere than sell an element that underperforms.

Credentials

The certificates, with their document numbers

Rather than describe the company's standing, we have put the paperwork on its own page — each item printed with the number on the document and the authority that signed it, so it can be checked instead of believed.

High-Tech Enterprise Certificate

Granted under China's national programme and signed jointly by the Jiangsu Provincial Department of Science and Technology, the Jiangsu Provincial Department of Finance and the Jiangsu Provincial Tax Service. The certificate requires the company to own its own patents and to sustain research spending, and it is re-assessed every three years.

Certificate number GR202332020406 · issued 13 December 2023 · term three years

High-Tech Enterprise Certificate issued to Jiangsu Zhongjie Environmental Technology Co., Ltd., certificate number GR202332020406
High-Tech Enterprise Certificate, 13 December 2023.
Quality & certification

Certified processes, and what they actually cover

ISO 9001Quality management system certification, held since 2020.
High-Tech EnterpriseNational certification obtained in 2023.
10 barMaximum inlet pressure of the tubular element range.

The certification covers three specific stages rather than the company in the abstract: membrane material formulation, element welding, and factory testing. Each stage is held to a written standard and each delivery carries a traceable record, which is the part that matters when a rack is commissioned two years after the elements were made.

Before dispatch, systems are assembled and wet-tested. Element dimensions and membrane area for the main models are published on the model code & specifications page, so you can design the rack and the pipework while the quotation is still in progress.

Product families

Four membrane lines

Microfiltration, ultrafiltration, special separation membranes and the integrated systems built from them. The tubular lines are the ones that carry the difficult feeds.

FamilyWhat it isTypical duty
Tubular UFOrganic tubular ultrafiltration, open channel, inside-out crossflowBiological sludge separation, oily wastewater, high-solids effluent
Tubular MFTubular microfiltration — the same open-channel geometry at a coarser ratingSolids and large-particle removal ahead of a finer stage
TMFChemical softening coupled with membrane separation in one stageHardness removal ahead of a high-recovery RO train
STRO / DTRODisc-tube and net-tube open-channel reverse osmosisLandfill leachate, brine concentration, zero-liquid-discharge trains
Integrated systemsSkid-mounted plants built around the aboveExternally mounted filtration, retrofits, containerised installations
Tubular membrane rack during on-site installation
Externally mounted filtration. The membrane sits outside the biological tank, so maintenance and element replacement do not disturb the main process.
Outdoor skid-mounted water treatment plant
Outdoor installation. Skid-mounted plant running in the open, pipework and instrumentation accessible for service.

Ask us the awkward question first

If your feed is out of range for a tubular element, we would rather tell you before a quotation is written. Send the peak solids, oil content and salinity and we will say which configuration to look at — including whether hollow fibre would do the job for less money.

Send your feed data