Liquid Waste Management
The most common method of treating industrial waste water is open lagoons in which large man-made ponds or lagoons are provided for settlement and further biological improvement through storage of waste water.
Lagoons are constructed and lined with material, such as clay or an artificial liner that will prevent leaks to the groundwater below. This is a slow and cheap treatment system that can be used for various types of wastewater.
They rely on the interaction of sunlight, algae, microorganisms and oxygen. Most of the starch, palm oil and sugar industries employ lagoons to treat their waste waters. We have visited various industries, which employ even more than 10-step lagoon systems.
Lagoons are also aerated. Aerobic systems can achieve 80 to 90% removal of BOD with retention time of 1 to 10 days. The basins may range in depth from 1.5 to 5.0 meters and utilise aerators. But due to the high electricity cost for aeration, most of the industries opt for anaerobic lagoons. To take advantage of the CER revenue from CDM, now-a-days industries tend to cover the anaerobic lagoons to capture the methane gas for power generation.
Modern method of treating industrial waste water is by installing advanced anaerobic digestion plants. Modern high rate reactors can reduce the COD of the waste water by 85-95%.
Biogas produced will be used for heat or electricity generation. The most commonly used systems are UASB, AFFR, CSTR and CIGAR.
 open lagoons in palm oil industry |
 open lagoons in starch industry |
 covered lagoons for methane recovery |
 sewage treatment plant |
 biogas reactors |
 biogas reactors |
 waste water treatment |
 gas engine |
Waste waters from starch plants, palm oil plants, ethanol plants, poultry farms, cattle farms and piggery farms are ideal for biogas generation and power plants. Not all types of industrial waste waters can be anaerobically treated. Extensive research is being carried out in Asia to treat these waste waters anaerobically.
Sewage refers to the municipal wastewater resulting from the mixing of waste waters from different sources disposed of, usually via a pipe or sewer and containing a broad spectrum of contaminants. If these liquid wastes are discharged into rivers, ponds, lands, etc., without proper treatment, it will result in offensive odour, pollution of water and air as they will emit gases like methane and carbon dioxide. By adopting environmental friendly technologies, these problems can be mitigated. These waste waters can be treated using numerous processes depending on the type and extent of contamination. A typical wastewater treatment plant includes physical, chemical and biological treatment processes. For services related to liquid waste management, contact us.