In-Situ DGT Lake Water Sampling Device for Eutrophication Analysis
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Solution Overview
Problem
Existing DGT test devices for lake water cannot perform in-situ testing at multiple depths, simultaneously collect water samples, and determine physicochemical properties, leading to inaccurate bioavailability and eutrophication assessments.
Innovation Solution
A DGT test device with a floating ball and vertically arranged water sampling units, each equipped with DGT detection, multi-parameter water quality probes, and sampling devices, allowing for in-situ testing at surface, intermediate, and sediment water layers, and simultaneous collection and analysis of nitrogen and phosphorus concentrations and physicochemical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ex-situ DGT piston test is conducted in a laboratory using collected water samples, then the test can be performed with controlled conditions, but the physicochemical properties (Eh, pH, temperature, conductivity) of water samples change during collection and storage, leading to distortion of element forms and bioavailability
Solution Approach 1:
The patent performs DGT testing in-situ at the water body location before the water samples are collected and transported to the laboratory. By conducting the diffusion gradient test preliminarily at the original location, the system captures the element bioavailability under the actual physicochemical conditions (pH, temperature, Eh) before these parameters change during sample collection and storage, thus resolving the contradiction between reliable measurement and sample stability
2Device complexity
If simple DGT test devices (PVC pipe, crutch-shaped structure, spindle device) are used for in-situ testing, then the device complexity is reduced, but the devices cannot accurately collect water samples from the DGT test area simultaneously, resulting in low sampling frequency and inability to compare with time-integrated DGT concentration
Solution Approach 1:
The patent merges the DGT piston testing function with the water sample collection function into a single integrated device. The DGT piston is positioned within the water sampling bottle assembly, allowing simultaneous execution of both the diffusion gradient test and the water sample collection from the same test area. This combination resolves the contradiction by enabling both functions without requiring separate complex devices, thereby maintaining simplicity while improving productivity
3Device complexity
If simple DGT test devices are used for in-situ testing, then the device structure is simplified, but the devices cannot simultaneously measure physicochemical properties (Eh, pH, DO, salinity, temperature) of the water at the test area, limiting the ability to study eutrophication mechanism at different depths
Solution Approach 1:
The patent designs the water sampling unit with multi-functional capabilities: it performs DGT piston testing for element bioavailability, collects water samples for later analysis, and simultaneously measures multiple physicochemical parameters (pH, temperature, dissolved oxygen, conductivity) using integrated sensors. This multi-functional design resolves the contradiction by enabling diverse measurements within a single simplified device structure, thereby enhancing adaptability without increasing complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate, time-integrated measurements of nitrogen and phosphorus bioavailability and physicochemical properties across different water depths, effectively studying lake water eutrophication mechanisms.
Implementation Method 1
DGT measures the amount of a solute that diffuses through a diffusive gel and a membrane filter where a concentration gradient forms
Implementation Method 2
after passing through the diffusive layer of DOT device, the solute is quickly bonded by a binding gel behind the diffusive gel, which continuously removes solutes and maintains the concentration gradient during operation
Data Source
AI summary
A diffusive gradients in thin films (DGT) test device for lake water, including: a floating ball and a plurality of water sampling units. A DGT detection device, a water quality detection device with a multi-parameter probe, and a water sampling device are disposed in each of the water sampling units. The water sampling device includes: a plurality of sampling bottles, each of the sampling bottles is provided with an inlet pipe and an exhaust pipe, each of the inlet pipes and exhaust pipes is provided with a one-way solenoid valve; a peristaltic pump, a water sample outlet of the peristaltic pump communicates with the inlet pipes of the plurality of sampling bottles via a multi-way connector; the exhaust pipes of the plurality of sampling bottles are connected to an exhaust manifold via a multi-way connector; a control device connected with the peristaltic pump and each of the one-way solenoid valves.