Can you please confirm the inlet TSS value from toilet flushing ? In your case it's only 124 ppm which I think is underestimated. Please let us know the method of sampling also ?

Akshay Shende

The data that I got from certified laboratory as shown in table. TSS value from inlet is 124 ppm.

I used manual sampling:

take a sample using a sampling tool (stainless dipper) and then put it into a sample bottle. before that, the sample bottle has been rinsed with the sample

I attached visual of the sample. Left side: inlet; right side: outlet

Please let me know your opinion Sir. Thanks in advance

Dear Mr. Yulinar,

Thanks for the photograph.

Rather than grab sampling, it would be better if you can take the composite sample.

May I also know the inlet sampling point ? Whether you take from the drainage line going to septic tank from toilet or you simply dip the sampler at the inlet of septic tank ?

I am attaching few of the values of wastewater from toilet/septic tank which will be useful to you (based on literature survey done by me).

Please see and try to compare with your data.

I am just simply took the sample from inlet chamber of septictank.

Thank for your information Sir. Akshay Shende

logically, anaerobic condition will will increase both biological and chemical oxygen demand because anaerobic bacteria will reduce all anions rich with oxygen like nitrate and sulfate in wastewater that originally have great load of organic waste that need to be degraded by bacteria,hence increasing BOD.

I think it is because of a lot of oils and detergents which were not degraded.

Thank you so much for answering my questions! Kiprotich Kiptum Mustafa Ismail Umer

Check https://www.mdpi.com/2073-4441/10/2/99/pdf

Also check https://www.scielo.br/j/bjce/a/xvDWWzh9kZKsqnv7sHrY8CL/?lang=en

Dear Kiprotich Kiptum,

Detergents do not exert any oxygen demand (its mostly inorganic).

Dear Mustafa,

Can you please elaborate "How reduction of oxy-anions in anaerobic treatment increases the chemical and bio-chemical oxygen demand ?"

Anaerobic Digestion (AD) affects the COD (especially the soluble COD) of the mixed liquor and promotes the dissociation of rbCOD due to fermentation and hydrolization of the organic complexes persist in the system. This effect is comparably higher in AD than that of aerobic exposure. In this way, though, your TSS, ammonia nitrogen and TN shall be decline at higher rate compared with the aerobic/anoxic treatment that would be a probable benefit. The excess COD or BOD can be easily neutralized by increasing the retention time of the clarifier or be implementing a short retention time aeration zone.

The problem is due to two factors:

1- the sampling was done during peak hours when the wastewater is loaded.

2- A 24 hour composite sampling must be done otherwise your results are normal.

Anaerobic wastewater treatment is a biological process where microorganisms degrade organic contaminants in the absence of oxygen. In a basic anaerobic treatment cycle, a semi-solid substance (sludge) is comprised of anaerobic bacteria and other microorganisms. These anaerobic microorganisms digest the biodegradable matter present in the wastewater, resulting in an effluent with lower biological oxygen demand (BOD), chemical oxygen demand (COD), and/or total suspended solids (TSS).

So, an increase in BOD and COD means a high load of pollution and a failure in treatment optimum condition.