• Continuous Record of effluent discharge
• SILVER, IRON, AMMONIUM, EDTA/PDTA, SULPHITE, COD.
• Immediate warnings if limits are exceeded
• Diagnostics to identify causes of excess effluents

The Photo-Lab Effluent Monitor serves a dual purpose.

1. Provides information and warnings to the QC and maintenance staff and thereby assists them to keep the lab within the effluent consent limits at the lowest possible cost
2. Generates records and reports of the level of the effluent for those responsible for compliance.

Using conventional methods to measure the levels of silver and other pollutants in wash water requires time consuming and costly analysis for which many photo labs are not equipped. The ROHIC effluent monitor uses an indirect method to provide this information continuously.

The effluent level in the wash water depends on the amounts of pollutants in the chemical tanks, on the correct wash water flows and on the performance of the squeegees.

The amount of chemistry carried into the wash tanks determines the conductivity of the discharge relative to the incoming fresh water

The ROHIC effluent monitor calculates the amount of fix, bleach-fix or other chemistry carried over into the wash tanks by measuring the change in conductivity. This measurement is converted into pollutant levels by taking into account the concentrations of silver etc. in the chemistry. Determining these is much simpler than analysis of the wash water.

Conductivity and water flow sensors in the wash tanks are connected to micro controllers called node deciders. These are connected to a PC via an RS485 serial link.

The PC uses the information form the sensors, together with the data from the chemical tanks, to calculate the concentrations in ppm (parts per million) and total mass of each of the pollutants discharged by each processor. these are then combined to give the total for the lab.

The quantities (grams/litre) of silver and other substances in the chemical tanks are entered as a parameter. In most cases this is acceptable, as having once been measured, they are fairly constant providing the processor is being operated correctly. There is however provision for inputting these values automatically from suitable sensors where these are available.

The monitor continually displays all the values in ppm and as a series of bar graphs which change colour form green to red if preset limits are exceeded. In addition warning lights on the node decoders change colour and an audible alarm is sounded. The displayed pollution levels are updated every few minutes.

All the data is saved and can be recalled, either on the screen or as print-outs in the form of clothesline graphs covering a period of days, weeks or months. Alternatively the measured data can be exported for further processing in spreadsheet or database programs.

These printed records provide the person responsible for compliance and the relevant authorities with the information to assess the environmental performance of the lab.

The system offers a number of other benefits.

The data can be used to optimise the performance of the low flow washes and thus reduce haul-away costs.

In a similar manner wash water consumption can be minimized. If any or all the wash water is being recycled, the data will assist in the operation of the wash water plant.

A further benefit id that the data can help in reducing the cost of squeegee maintenance.

the effluent monitors are specifically configured for each lab and can handle any number of processors. They can operate in conjunction with the other ROHIC devices monitoring or controlling pH, specific gravity, replenishment or temperature.

See ROHIC Intelligent Chemical Controls brochure and application notes for more detailed description of the system

Effluent Monitor Brochure

Squeegee Monitor Brochure

pH Measuring Equipment Brochure