Accurate Flow Measurement in Large Pipes

The ADFM Pro20 from Teledyne Isco (USA) brings unparalleled flow measurement accuracy to large pipes and channels, delivering flow rate data within 2% of actual value, in flow depths up to 20 feet (6m). Four (4) piezoelectric ceramics in the sensor emit short pulses along narrow acoustic beams pointing in different directions to measure velocity. A fifth ceramic mounted in the center of assembly, and aimed vertically, is used to measure the depth.

Each acoustic beam measures velocity at multiple points, known as bin, in the water column. The measured velocity data each bin are very precise- to within 0.01ft/s. The distribution accurate velocity measurement is then used to determined the flow pattern over the entire cross-section flow. Since the flow pattern and measured velocity distribution are dependent to each other, the ADFM's advanced flow algorithms automatically adapt to changing hydraulic condition within the pipe. the removes the need for in-situ calibration and insures flow rate measurement over a host of different measurement environments and hydraulic condition.

The ADFM enclosure houses the signal processing, data logging, and data output electronics. The enclosure is available as NEMA 4X Box housing, suitable for wall or console mounting in permanent application, and NEMA 6P cylindrical housing for use in manholes or other 'wet' environments.

Continous Toxicity Monitoring

Cymtox (UK) is wholly owned subsidiary of modern water pic. It develops and markets leading-edge water and wastewater monitoring solutions.

Online Real time Detection of toxic agents in water and wastewater monitoring of water toxicity using biosensors has become a widely accepted technique. Bacterial bio-sensors is offer simple and reproducible tests that can be automated, with reagents that can be stored. The new CTM (TM) Continuous Toxicity Monitor makes fully automatic, continuous, online testing a reality.

Certain strains of bacteria emit light when healthy, when they are exposed to toxic substances, the amount of light emitted reduces. The greater the toxicity of the sample, the lower the lights emmited. This has been shown over many years to be a reproducible effects. Measuring change in light between helaty bacteria and bacteria exposed to toxic substances will therefore indicate presence in water sample.

The CTM (TM) Continuous Toxicity Monitor automatically and simultaneously detects a broad range of toxictants including metals, pesticides, fungicides, herbicides, chlorinated solvents, industrial chemicals and algal toxin. The presence of harmful contaminants in water and wastewater is detected without having to monitor for a wide range of specific chemicals.

Processing soil samples for nutrient analysis

What is soil?

Soil is the loose covering the earth's topmost surface, which is practically always active.

Downwards the soil is bordered by solid or loose rocks. towards the top it is mostly bordered by a cover of vegetation, as well as atmosphere. Where the topmost layer of soil is covered by water, lakes, rivers and oceans it is considered sediment rather than soil can be defined differently.

Term of soil catogorised according to DIN 4022

Gravel - the fraction of the soil with diameter <2mm is considered as gravel, which again is divided into coarse, medium and fine gravel.

Sand- The grain fraction between 0.063mm and 2.0mm is identified as sand, which again is differentiated into coarse, medium and fine sand.

Coarse clay or silt - Contents of the soil equivalence diameter between 0.002mm and 0.063mm are grouped in coarse, medium and fine silt. The cohosive soil layer is referred in general terms also as clay.

Clay- Elements of the soil smaller than 0.002mm are considered as clay.

Soil and nutrient

Scientifically it is proven, that all segments of gravel - the contents of the soil larger than 2mm - are not available as nutrients for plants and also do not bond nutrients. It also referred to as coarse soil. ALl soil contents with on equivalence diameter of 2mm and smaller however, deliver nutrients for the plants themselves or bind nutrients for the plants. For example in the form of added fertiliser. This type fraction is considered as fine soil


Preparing soil samples

For preparation of agricultural soil samples for the analysis of nutrients, the VDLUFA demands in the book of methods volume 1 "analysis of soils" the seperation of coarse and fine soil.

for examination of radioactivity in the environment, the pre-treatment of the sample is described in DIN ISO 18589-2 radioactivity in environment- soil part 2

Also for examination of past polluted areas, the Federal Soil Protection and Past Contaminated Area Ordinance, assumes a separation at 2mm.

Environmental Monitoring in Landfill

The impact of landfills on the local population is convinced Pollution S.r.I (Italy) to develop an analytical system for environmental pollution. Currently, surveys for environmental analysis are carried out discontinuously. Air samplers are taken at regular time intervals and canister are analysed in laboratory. As a results the absence of continuous monitoring and delayed response does not allow real time action and tracking of the pollutants.

Latest the HAPSITE GC-MS (Gas Chromatography-Mass Spectrometry)system provides insights on the analysis of volatile organic compounds (VOCs) in environmental hazardous waste treatment and industrial hygine. On site critical information can be achieved in fast and reliable way.

The process of continuous monitoring was then performed using portable micro gas-cinematographer (Vega-CG) and multi point sampler (vega-MPS) which also produced and distributed by Pollution S.r.I

Vega MPS has a function to send in sequence to Vega-GC the samples 'sucked' at different points inside or on the neighborhood of the landfill. This system consists in a network of pipes of inert material (PTFE) and the intake air is continuously pumped in each line to ensure fresh and not diluted samples. Between sampler and analyzer a concentrator EDU-3 from Airsense Analytics (Germany) has been placed to increase the sensitivity of the monitoring systems.

Using the MC-Plan software integrated in the computer of the Vega-GC, it is possible to record the chemical composition of the sampling point at the specific sampling time and to compare the concentration of each component with the TLV level (threshold limit value). If the threshold level is exceeded on one several points, an alert massage is sent by email or to the mobile phone through a remote PC to graphically display the concentration trend during last hour in order to perform a deep analysis.

Grab Samplers for slow moving river or streams

There are 3 types of grab samplers available

EakmanBottom Grab Samplers

The Ekman Bottom Grab sampler is designed for sampling in soft bottomed lakes and rivers composed of muck, mud or fine peat. As the sampler is lowered, two hinged upper lids swing open to let water pass through and close upon retrieval preventing sample washout. When the sampler reaches the bottom, a messenger is sent down the line tripping the overlapping spring-loaded scoops. Each sampler is constructed of 316 stainless steel including the springs, cables and fasteners. Also available is a 5 ft. and 10 ft. extension handle for operating the sampler in shallow water instead of a cable and messenger. The sampler is also available as a kit which includes stainless 300 gm messenger, 100 ft. cable and carrying case (ordered separately).

Ponar type grab samplers

The Ponar Type Grab sampler is a commonly used sampler that is very versatile for all types of hard bottoms such as sand, gravel and clay. It can be used in streams, lakes reservoirs and the ocean. This modified Van Veen type self-tripping sampler features center hinged jaws and a spring loaded pin that releases when the sampler makes impact with the bottom. It also includes an underlip attachment that cleans gravel from the jaws that would normally prevent lateral loss of sample. The top is covered with a stainless steel screen with neoprene rubber flaps which allows water to flow through for a controlled descent and less interference with the sample. It is constructed of stainless steel with zinc plated steel arms and weights. A simple pin prevents premature closing.

The Ponar style sampler comes in several sizes with the lightweight model (1/8" stainless plate) easily used from a small boat with nylon cable. The heavyweight models (1/4" stainless plate) should be used with a sounding reel.

Van Veen Grab Sampler

The Van Veen grab is a lightweight sampler designed to take large samples in soft bottoms. Its long lever arms and the sharp cutting edges on the bottom of the scoops, enable it to cut deeply into the softer bottoms. The Van Veen grab sampler is manufactured in two sizes from stainless steel. The weighted jaws, chain suspension, and doors and screens allow flow-through during lowering to the bottom and assure vertical descent where strong underwater currents exist. The relatively large surface area and the strong closing mechanism allow the jaws to excavate relatively undisturbed sediments. When the powering cable is slowly made taut, the chains attached at the top of the release exert great tension on the long arms extending beyond the jaws, causing them to lift, dip deeper into the sediment, and trap material as they tightly close. The stainless-steel, 583 micron, door screens have flexible rubber flaps which, during lowering, are lifted. When the grab settles on the bottom, the flaps fall back and cover the screens completely, preventing any loss of sediment during retrieval.